[dev.power64] build: merge default into dev.power64

LGTM=rsc
R=rsc
CC=golang-codereviews
https://codereview.appspot.com/160200044

193 files changed, 2765 insertions, 2132 deletions

diff --git a/src/cmd/5c/cgen.c b/src/cmd/5c/cgen.c
index 08ed36055..5ea8eea07 100644
--- a/src/cmd/5c/cgen.c
+++ b/src/cmd/5c/cgen.c
@@ -46,7 +46,7 @@ _cgen(Node *n, Node *nn, int inrel)
 	}
 	if(n == Z || n->type == T)
 		return;
-	if(typesuv[n->type->etype]) {
+	if(typesuv[n->type->etype] && (n->op != OFUNC || nn != Z)) {
 		sugen(n, nn, n->type->width);
 		return;
 	}
@@ -75,7 +75,7 @@ _cgen(Node *n, Node *nn, int inrel)
 	if(r != Z && r->complex >= FNX)
 	switch(o) {
 	default:
-		regret(&nod, r);
+		regret(&nod, r, 0, 0);
 		cgen(r, &nod);
 
 		regsalloc(&nod1, r);
@@ -107,7 +107,7 @@ _cgen(Node *n, Node *nn, int inrel)
 		if(l->addable >= INDEXED && l->complex < FNX) {
 			if(nn != Z || r->addable < INDEXED) {
 				if(r->complex >= FNX && nn == Z)
-					regret(&nod, r);
+					regret(&nod, r, 0, 0);
 				else
 					regalloc(&nod, r, nn);
 				cgen(r, &nod);
@@ -348,7 +348,7 @@ _cgen(Node *n, Node *nn, int inrel)
 			if(l->op != OIND)
 				diag(n, "bad function call");
 
-			regret(&nod, l->left);
+			regret(&nod, l->left, 0, 0);
 			cgen(l->left, &nod);
 			regsalloc(&nod1, l->left);
 			gopcode(OAS, &nod, Z, &nod1);
@@ -377,11 +377,11 @@ _cgen(Node *n, Node *nn, int inrel)
 		if(REGARG >= 0)
 			if(o != reg[REGARG])
 				reg[REGARG]--;
-		if(nn != Z) {
-			regret(&nod, n);
-			gopcode(OAS, &nod, Z, nn);
+		regret(&nod, n, l->type, 1);
+		if(nn != Z)
+			gmove(&nod, nn);
+		if(nod.op == OREGISTER)
 			regfree(&nod);
-		}
 		break;
 
 	case OIND:
@@ -823,7 +823,7 @@ boolgen(Node *n, int true, Node *nn)
 		if(true)
 			o = comrel[relindex(o)];
 		if(l->complex >= FNX && r->complex >= FNX) {
-			regret(&nod, r);
+			regret(&nod, r, 0, 0);
 			cgenrel(r, &nod);
 			regsalloc(&nod1, r);
 			gopcode(OAS, &nod, Z, &nod1);
@@ -957,7 +957,7 @@ sugen(Node *n, Node *nn, int32 w)
 		if(nn != Z && side(nn)) {
 			nod1 = *n;
 			nod1.type = typ(TIND, n->type);
-			regret(&nod2, &nod1);
+			regret(&nod2, &nod1, 0, 0);
 			lcgen(nn, &nod2);
 			regsalloc(&nod0, &nod1);
 			gopcode(OAS, &nod2, Z, &nod0);
@@ -1036,6 +1036,20 @@ sugen(Node *n, Node *nn, int32 w)
 		break;
 
 	case OFUNC:
+		if(!hasdotdotdot(n->left->type)) {
+			cgen(n, Z);
+			if(nn != Z) {
+				curarg -= n->type->width;
+				regret(&nod1, n, n->left->type, 1);
+				if(nn->complex >= FNX) {
+					regsalloc(&nod2, n);
+					cgen(&nod1, &nod2);
+					nod1 = nod2;
+				}
+				cgen(&nod1, nn);
+			}
+			break;
+		}
 		if(nn == Z) {
 			sugen(n, nodrat, w);
 			break;
diff --git a/src/cmd/5c/gc.h b/src/cmd/5c/gc.h
index 166900c3a..7417b7dbe 100644
--- a/src/cmd/5c/gc.h
+++ b/src/cmd/5c/gc.h
@@ -210,7 +210,7 @@ void	usedset(Node*, int);
 void	xcom(Node*);
 int	bcomplex(Node*, Node*);
 Prog*	gtext(Sym*, int32);
-vlong	argsize(void);
+vlong	argsize(int);
 
 /*
  * cgen.c
@@ -236,7 +236,7 @@ Node*	nodconst(int32);
 Node*	nod32const(vlong);
 Node*	nodfconst(double);
 void	nodreg(Node*, Node*, int);
-void	regret(Node*, Node*);
+void	regret(Node*, Node*, Type*, int);
 int	tmpreg(void);
 void	regalloc(Node*, Node*, Node*);
 void	regfree(Node*);
diff --git a/src/cmd/5c/sgen.c b/src/cmd/5c/sgen.c
index efcc0437b..a36612caa 100644
--- a/src/cmd/5c/sgen.c
+++ b/src/cmd/5c/sgen.c
@@ -36,7 +36,7 @@ gtext(Sym *s, int32 stkoff)
 {
 	int32 a;
 
-	a = argsize();
+	a = argsize(1);
 	if((textflag & NOSPLIT) != 0 && stkoff >= 128)
 		yyerror("stack frame too large for NOSPLIT function");
 
diff --git a/src/cmd/5c/swt.c b/src/cmd/5c/swt.c
index d24a5df9b..f39963b8f 100644
--- a/src/cmd/5c/swt.c
+++ b/src/cmd/5c/swt.c
@@ -374,10 +374,11 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 {
 	int32 o;
 	Type *v;
-	int w;
+	int w, packw;
 
 	o = i;
 	w = 1;
+	packw = 0;
 	switch(op) {
 	default:
 		diag(Z, "unknown align opcode %d", op);
@@ -388,7 +389,7 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		if(w < 1)
 			w = 1;
 		if(packflg)
-			w = packflg;
+			packw = packflg;
 		break;
 
 	case Ael1:	/* initial align of struct element */
@@ -404,7 +405,7 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		if(w < 1 || w > SZ_LONG)
 			fatal(Z, "align");
 		if(packflg) 
-			w = packflg;
+			packw = packflg;
 		break;
 
 	case Ael2:	/* width of a struct element */
@@ -440,6 +441,8 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		w = SZ_LONG;	/* because of a pun in cc/dcl.c:contig() */
 		break;
 	}
+	if(packw != 0 && xround(o, w) != xround(o, packw))
+		diag(Z, "#pragma pack changes offset of %T", t);
 	o = xround(o, w);
 	if(maxalign != nil && *maxalign < w)
 		*maxalign = w;
diff --git a/src/cmd/5c/txt.c b/src/cmd/5c/txt.c
index a753510ca..af40220cc 100644
--- a/src/cmd/5c/txt.c
+++ b/src/cmd/5c/txt.c
@@ -274,15 +274,43 @@ nodreg(Node *n, Node *nn, int reg)
 }
 
 void
-regret(Node *n, Node *nn)
+regret(Node *n, Node *nn, Type *t, int mode)
 {
 	int r;
 
-	r = REGRET;
-	if(typefd[nn->type->etype])
-		r = FREGRET+NREG;
-	nodreg(n, nn, r);
-	reg[r]++;
+	if(mode == 0 || hasdotdotdot(t) || nn->type->width == 0) {
+		r = REGRET;
+		if(typefd[nn->type->etype])
+			r = FREGRET+NREG;
+		nodreg(n, nn, r);
+		reg[r]++;
+		return;
+	}
+	
+	if(mode == 1) {
+		// fetch returned value after call.
+		// already called gargs, so curarg is set.
+		curarg = (curarg+3) & ~3;
+		regaalloc(n, nn);
+		return;
+	}
+	
+	if(mode == 2) {
+		// store value to be returned.
+		// must compute arg offset.
+		if(t->etype != TFUNC)
+			fatal(Z, "bad regret func %T", t);
+		*n = *nn;
+		n->op = ONAME;
+		n->class = CPARAM;
+		n->sym = slookup(".ret");
+		n->complex = nodret->complex;
+		n->xoffset = argsize(0);
+		n->addable = 20;
+		return;
+	}
+	
+	fatal(Z, "bad regret");
 }
 
 int
diff --git a/src/cmd/5g/cgen.c b/src/cmd/5g/cgen.c
index a42e67baf..5fae7a564 100644
--- a/src/cmd/5g/cgen.c
+++ b/src/cmd/5g/cgen.c
@@ -254,7 +254,6 @@ cgen(Node *n, Node *res)
 	case OOR:
 	case OXOR:
 	case OADD:
-	case OADDPTR:
 	case OMUL:
 		a = optoas(n->op, nl->type);
 		goto sbop;
@@ -1635,7 +1634,10 @@ int
 componentgen(Node *nr, Node *nl)
 {
 	Node nodl, nodr, tmp;
+	Type *t;
 	int freel, freer;
+	vlong fldcount;
+	vlong loffset, roffset;
 
 	freel = 0;
 	freer = 0;
@@ -1645,8 +1647,33 @@ componentgen(Node *nr, Node *nl)
 		goto no;
 
 	case TARRAY:
-		if(!isslice(nl->type))
+		t = nl->type;
+
+		// Slices are ok.
+		if(isslice(t))
+			break;
+		// Small arrays are ok.
+		if(t->bound > 0 && t->bound <= 3 && !isfat(t->type))
+			break;
+
+		goto no;
+
+	case TSTRUCT:
+		// Small structs with non-fat types are ok.
+		// Zero-sized structs are treated separately elsewhere.
+		fldcount = 0;
+		for(t=nl->type->type; t; t=t->down) {
+			if(isfat(t->type))
+				goto no;
+			if(t->etype != TFIELD)
+				fatal("componentgen: not a TFIELD: %lT", t);
+			fldcount++;
+		}
+		if(fldcount == 0 || fldcount > 4)
 			goto no;
+
+		break;
+
 	case TSTRING:
 	case TINTER:
 		break;
@@ -1674,6 +1701,7 @@ componentgen(Node *nr, Node *nl)
 		freer = 1;
 	}
 
+	
 	// nl and nr are 'cadable' which basically means they are names (variables) now.
 	// If they are the same variable, don't generate any code, because the
 	// VARDEF we generate will mark the old value as dead incorrectly.
@@ -1683,8 +1711,25 @@ componentgen(Node *nr, Node *nl)
 
 	switch(nl->type->etype) {
 	case TARRAY:
+		// componentgen for arrays.
 		if(nl->op == ONAME)
 			gvardef(nl);
+		t = nl->type;
+		if(!isslice(t)) {
+			nodl.type = t->type;
+			nodr.type = nodl.type;
+			for(fldcount=0; fldcount < t->bound; fldcount++) {
+				if(nr == N)
+					clearslim(&nodl);
+				else
+					gmove(&nodr, &nodl);
+				nodl.xoffset += t->type->width;
+				nodr.xoffset += t->type->width;
+			}
+			goto yes;
+		}
+
+		// componentgen for slices.
 		nodl.xoffset += Array_array;
 		nodl.type = ptrto(nl->type->type);
 
@@ -1759,6 +1804,31 @@ componentgen(Node *nr, Node *nl)
 		gmove(&nodr, &nodl);
 
 		goto yes;
+
+	case TSTRUCT:
+		if(nl->op == ONAME)
+			gvardef(nl);
+		loffset = nodl.xoffset;
+		roffset = nodr.xoffset;
+		// funarg structs may not begin at offset zero.
+		if(nl->type->etype == TSTRUCT && nl->type->funarg && nl->type->type)
+			loffset -= nl->type->type->width;
+		if(nr != N && nr->type->etype == TSTRUCT && nr->type->funarg && nr->type->type)
+			roffset -= nr->type->type->width;
+
+		for(t=nl->type->type; t; t=t->down) {
+			nodl.xoffset = loffset + t->width;
+			nodl.type = t->type;
+
+			if(nr == N)
+				clearslim(&nodl);
+			else {
+				nodr.xoffset = roffset + t->width;
+				nodr.type = nodl.type;
+				gmove(&nodr, &nodl);
+			}
+		}
+		goto yes;
 	}
 
 no:
diff --git a/src/cmd/5g/gsubr.c b/src/cmd/5g/gsubr.c
index 1241a23ea..5a70fcdda 100644
--- a/src/cmd/5g/gsubr.c
+++ b/src/cmd/5g/gsubr.c
@@ -1599,7 +1599,6 @@ optoas(int op, Type *t)
 	case CASE(OADD, TINT32):
 	case CASE(OADD, TUINT32):
 	case CASE(OADD, TPTR32):
-	case CASE(OADDPTR, TPTR32):
 		a = AADD;
 		break;
 
diff --git a/src/cmd/5g/reg.c b/src/cmd/5g/reg.c
index d259a232e..8e49a2d9c 100644
--- a/src/cmd/5g/reg.c
+++ b/src/cmd/5g/reg.c
@@ -1315,6 +1315,7 @@ void
 addreg(Adr *a, int rn)
 {
 	a->sym = nil;
+	a->node = nil;
 	a->name = D_NONE;
 	a->type = D_REG;
 	a->reg = rn;
diff --git a/src/cmd/5l/asm.c b/src/cmd/5l/asm.c
index 02b4c78f1..9c1c04e2d 100644
--- a/src/cmd/5l/asm.c
+++ b/src/cmd/5l/asm.c
@@ -599,10 +599,10 @@ asmb(void)
 			if(iself)
 				goto ElfSym;
 		case Hplan9:
-			symo = HEADR+segtext.len+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			break;
 		ElfSym:
-			symo = rnd(HEADR+segtext.filelen, INITRND)+rnd(HEADR+segrodata.filelen, INITRND)+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			symo = rnd(symo, INITRND);
 			break;
 		}
diff --git a/src/cmd/6a/lex.c b/src/cmd/6a/lex.c
index 167e6b6c1..b50e1622e 100644
--- a/src/cmd/6a/lex.c
+++ b/src/cmd/6a/lex.c
@@ -435,49 +435,49 @@ struct
 	"IRETQ",	LTYPE0,	AIRETQ,
 	"IRETW",	LTYPE0,	AIRETW,
 
-	"JOS",		LTYPER,	AJOS,
+	"JOS",		LTYPER,	AJOS,	/* overflow set (OF = 1) */
 	"JO",		LTYPER,	AJOS,	/* alternate */
-	"JOC",		LTYPER,	AJOC,
+	"JOC",		LTYPER,	AJOC,	/* overflow clear (OF = 0) */
 	"JNO",		LTYPER,	AJOC,	/* alternate */
-	"JCS",		LTYPER,	AJCS,
+	"JCS",		LTYPER,	AJCS,	/* carry set (CF = 1) */
 	"JB",		LTYPER,	AJCS,	/* alternate */
 	"JC",		LTYPER,	AJCS,	/* alternate */
 	"JNAE",		LTYPER,	AJCS,	/* alternate */
 	"JLO",		LTYPER,	AJCS,	/* alternate */
-	"JCC",		LTYPER,	AJCC,
+	"JCC",		LTYPER,	AJCC,	/* carry clear (CF = 0) */
 	"JAE",		LTYPER,	AJCC,	/* alternate */
 	"JNB",		LTYPER,	AJCC,	/* alternate */
 	"JNC",		LTYPER,	AJCC,	/* alternate */
 	"JHS",		LTYPER,	AJCC,	/* alternate */
-	"JEQ",		LTYPER,	AJEQ,
+	"JEQ",		LTYPER,	AJEQ,	/* equal (ZF = 1) */
 	"JE",		LTYPER,	AJEQ,	/* alternate */
 	"JZ",		LTYPER,	AJEQ,	/* alternate */
-	"JNE",		LTYPER,	AJNE,
+	"JNE",		LTYPER,	AJNE,	/* not equal (ZF = 0) */
 	"JNZ",		LTYPER,	AJNE,	/* alternate */
-	"JLS",		LTYPER,	AJLS,
+	"JLS",		LTYPER,	AJLS,	/* lower or same (unsigned) (CF = 1 || ZF = 1) */
 	"JBE",		LTYPER,	AJLS,	/* alternate */
 	"JNA",		LTYPER,	AJLS,	/* alternate */
-	"JHI",		LTYPER,	AJHI,
+	"JHI",		LTYPER,	AJHI,	/* higher (unsigned) (CF = 0 && ZF = 0) */
 	"JA",		LTYPER,	AJHI,	/* alternate */
 	"JNBE",		LTYPER,	AJHI,	/* alternate */
-	"JMI",		LTYPER,	AJMI,
+	"JMI",		LTYPER,	AJMI,	/* negative (minus) (SF = 1) */
 	"JS",		LTYPER,	AJMI,	/* alternate */
-	"JPL",		LTYPER,	AJPL,
+	"JPL",		LTYPER,	AJPL,	/* non-negative (plus) (SF = 0) */
 	"JNS",		LTYPER,	AJPL,	/* alternate */
-	"JPS",		LTYPER,	AJPS,
+	"JPS",		LTYPER,	AJPS,	/* parity set (PF = 1) */
 	"JP",		LTYPER,	AJPS,	/* alternate */
 	"JPE",		LTYPER,	AJPS,	/* alternate */
-	"JPC",		LTYPER,	AJPC,
+	"JPC",		LTYPER,	AJPC,	/* parity clear (PF = 0) */
 	"JNP",		LTYPER,	AJPC,	/* alternate */
 	"JPO",		LTYPER,	AJPC,	/* alternate */
-	"JLT",		LTYPER,	AJLT,
+	"JLT",		LTYPER,	AJLT,	/* less than (signed) (SF != OF) */
 	"JL",		LTYPER,	AJLT,	/* alternate */
 	"JNGE",		LTYPER,	AJLT,	/* alternate */
-	"JGE",		LTYPER,	AJGE,
+	"JGE",		LTYPER,	AJGE,	/* greater than or equal (signed) (SF = OF) */
 	"JNL",		LTYPER,	AJGE,	/* alternate */
-	"JLE",		LTYPER,	AJLE,
+	"JLE",		LTYPER,	AJLE,	/* less than or equal (signed) (ZF = 1 || SF != OF) */
 	"JNG",		LTYPER,	AJLE,	/* alternate */
-	"JGT",		LTYPER,	AJGT,
+	"JGT",		LTYPER,	AJGT,	/* greater than (signed) (ZF = 0 && SF = OF) */
 	"JG",		LTYPER,	AJGT,	/* alternate */
 	"JNLE",		LTYPER,	AJGT,	/* alternate */
 	"JCXZL",	LTYPER,	AJCXZL,
@@ -612,7 +612,7 @@ struct
 	"SCASL",	LTYPE0,	ASCASL,
 	"SCASQ",	LTYPE0,	ASCASQ,
 	"SCASW",	LTYPE0,	ASCASW,
-	"SETCC",	LTYPE1,	ASETCC,
+	"SETCC",	LTYPE1,	ASETCC,	/* see JCC etc above for condition codes */
 	"SETCS",	LTYPE1,	ASETCS,
 	"SETEQ",	LTYPE1,	ASETEQ,
 	"SETGE",	LTYPE1,	ASETGE,
diff --git a/src/cmd/6c/cgen.c b/src/cmd/6c/cgen.c
index bdef76ff0..b66c6add3 100644
--- a/src/cmd/6c/cgen.c
+++ b/src/cmd/6c/cgen.c
@@ -51,7 +51,7 @@ cgen(Node *n, Node *nn)
 	}
 	if(n == Z || n->type == T)
 		return;
-	if(typesu[n->type->etype]) {
+	if(typesu[n->type->etype] && (n->op != OFUNC || nn != Z)) {
 		sugen(n, nn, n->type->width);
 		return;
 	}
@@ -88,7 +88,7 @@ cgen(Node *n, Node *nn)
 		if(cond(o) && typesu[l->type->etype])
 			break;
 
-		regret(&nod, r);
+		regret(&nod, r, 0, 0);
 		cgen(r, &nod);
 
 		regsalloc(&nod1, r);
@@ -135,7 +135,7 @@ cgen(Node *n, Node *nn)
 		if(!hardleft) {
 			if(nn != Z || r->addable < INDEXED || hardconst(r)) {
 				if(r->complex >= FNX && nn == Z)
-					regret(&nod, r);
+					regret(&nod, r, 0, 0);
 				else
 					regalloc(&nod, r, nn);
 				cgen(r, &nod);
@@ -929,7 +929,7 @@ cgen(Node *n, Node *nn)
 			if(l->op != OIND)
 				diag(n, "bad function call");
 
-			regret(&nod, l->left);
+			regret(&nod, l->left, 0, 0);
 			cgen(l->left, &nod);
 			regsalloc(&nod1, l->left);
 			gmove(&nod, &nod1);
@@ -956,11 +956,13 @@ cgen(Node *n, Node *nn)
 		gpcdata(PCDATA_ArgSize, -1);
 		if(REGARG >= 0 && reg[REGARG])
 			reg[REGARG]--;
-		if(nn != Z) {
-			regret(&nod, n);
+		regret(&nod, n, l->type, 1); // update maxarg if nothing else
+		gpcdata(PCDATA_ArgSize, curarg);
+		gpcdata(PCDATA_ArgSize, -1);
+		if(nn != Z)
 			gmove(&nod, nn);
+		if(nod.op == OREGISTER)
 			regfree(&nod);
-		}
 		break;
 
 	case OIND:
@@ -1382,7 +1384,7 @@ boolgen(Node *n, int true, Node *nn)
 		if(true)
 			o = comrel[relindex(o)];
 		if(l->complex >= FNX && r->complex >= FNX) {
-			regret(&nod, r);
+			regret(&nod, r, 0, 0);
 			cgen(r, &nod);
 			regsalloc(&nod1, r);
 			gmove(&nod, &nod1);
@@ -1535,7 +1537,7 @@ sugen(Node *n, Node *nn, int32 w)
 		if(nn != Z && side(nn)) {
 			nod1 = *n;
 			nod1.type = typ(TIND, n->type);
-			regret(&nod2, &nod1);
+			regret(&nod2, &nod1, 0, 0);
 			lcgen(nn, &nod2);
 			regsalloc(&nod0, &nod1);
 			cgen(&nod2, &nod0);
@@ -1617,6 +1619,20 @@ sugen(Node *n, Node *nn, int32 w)
 		break;
 
 	case OFUNC:
+		if(!hasdotdotdot(n->left->type)) {
+			cgen(n, Z);
+			if(nn != Z) {
+				curarg -= n->type->width;
+				regret(&nod1, n, n->left->type, 1);
+				if(nn->complex >= FNX) {
+					regsalloc(&nod2, n);
+					cgen(&nod1, &nod2);
+					nod1 = nod2;
+				}
+				cgen(&nod1, nn);
+			}
+			break;
+		}
 		if(nn == Z) {
 			sugen(n, nodrat, w);
 			break;
diff --git a/src/cmd/6c/gc.h b/src/cmd/6c/gc.h
index bc4e36ccd..aa9d95d21 100644
--- a/src/cmd/6c/gc.h
+++ b/src/cmd/6c/gc.h
@@ -210,7 +210,7 @@ void	xcom(Node*);
 void	indx(Node*);
 int	bcomplex(Node*, Node*);
 Prog*	gtext(Sym*, int32);
-vlong	argsize(void);
+vlong	argsize(int);
 
 /*
  * cgen.c
@@ -239,7 +239,7 @@ Node*	nodfconst(double);
 Node*	nodgconst(vlong, Type*);
 int	nodreg(Node*, Node*, int);
 int	isreg(Node*, int);
-void	regret(Node*, Node*);
+void	regret(Node*, Node*, Type*, int);
 void	regalloc(Node*, Node*, Node*);
 void	regfree(Node*);
 void	regialloc(Node*, Node*, Node*);
diff --git a/src/cmd/6c/sgen.c b/src/cmd/6c/sgen.c
index ba1c1f652..d99510185 100644
--- a/src/cmd/6c/sgen.c
+++ b/src/cmd/6c/sgen.c
@@ -36,7 +36,7 @@ gtext(Sym *s, int32 stkoff)
 {
 	vlong v;
 
-	v = ((uvlong)argsize() << 32) | (stkoff & 0xffffffff);
+	v = ((uvlong)argsize(1) << 32) | (stkoff & 0xffffffff);
 	if((textflag & NOSPLIT) && stkoff >= 128)
 		yyerror("stack frame too large for NOSPLIT function");
 
@@ -124,10 +124,7 @@ xcom(Node *n)
 		break;
 
 	case ONAME:
-		if(flag_largemodel)
-			n->addable = 9;
-		else
-			n->addable = 10;
+		n->addable = 9;
 		if(n->class == CPARAM || n->class == CAUTO)
 			n->addable = 11;
 		break;
diff --git a/src/cmd/6c/swt.c b/src/cmd/6c/swt.c
index d7713648d..6e918eb10 100644
--- a/src/cmd/6c/swt.c
+++ b/src/cmd/6c/swt.c
@@ -250,10 +250,11 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 {
 	int32 o;
 	Type *v;
-	int w;
+	int w, packw;
 
 	o = i;
 	w = 1;
+	packw = 0;
 	switch(op) {
 	default:
 		diag(Z, "unknown align opcode %d", op);
@@ -264,7 +265,7 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		if(w < 1)
 			w = 1;
 		if(packflg)
-			w = packflg;
+			packw = packflg;
 		break;
 
 	case Ael1:	/* initial align of struct element */
@@ -277,7 +278,7 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		if(w < 1 || w > SZ_VLONG)
 			fatal(Z, "align");
 		if(packflg) 
-			w = packflg;
+			packw = packflg;
 		break;
 
 	case Ael2:	/* width of a struct element */
@@ -331,6 +332,8 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		o = align(o, t, Ael2, nil);
 		break;
 	}
+	if(packw != 0 && xround(o, w) != xround(o, packw))
+		diag(Z, "#pragma pack changes offset of %T", t);
 	o = xround(o, w);
 	if(maxalign && *maxalign < w)
 		*maxalign = w;
diff --git a/src/cmd/6c/txt.c b/src/cmd/6c/txt.c
index 4d07436c3..3bdbf410e 100644
--- a/src/cmd/6c/txt.c
+++ b/src/cmd/6c/txt.c
@@ -351,15 +351,43 @@ nodreg(Node *n, Node *nn, int r)
 }
 
 void
-regret(Node *n, Node *nn)
+regret(Node *n, Node *nn, Type *t, int mode)
 {
 	int r;
+	
+	if(mode == 0 || hasdotdotdot(t) || nn->type->width == 0) {
+		r = REGRET;
+		if(typefd[nn->type->etype])
+			r = FREGRET;
+		nodreg(n, nn, r);
+		reg[r]++;
+		return;
+	}
+	
+	if(mode == 1) {
+		// fetch returned value after call.
+		// already called gargs, so curarg is set.
+		curarg = (curarg+7) & ~7;
+		regaalloc(n, nn);
+		return;
+	}
 
-	r = REGRET;
-	if(typefd[nn->type->etype])
-		r = FREGRET;
-	nodreg(n, nn, r);
-	reg[r]++;
+	if(mode == 2) {
+		// store value to be returned.
+		// must compute arg offset.
+		if(t->etype != TFUNC)
+			fatal(Z, "bad regret func %T", t);
+		*n = *nn;
+		n->op = ONAME;
+		n->class = CPARAM;
+		n->sym = slookup(".ret");
+		n->complex = nodret->complex;
+		n->addable = 20;
+		n->xoffset = argsize(0);
+		return;
+	}
+	
+	fatal(Z, "bad regret");	
 }
 
 void
diff --git a/src/cmd/6g/cgen.c b/src/cmd/6g/cgen.c
index 4dd505b08..592e81542 100644
--- a/src/cmd/6g/cgen.c
+++ b/src/cmd/6g/cgen.c
@@ -247,7 +247,6 @@ cgen(Node *n, Node *res)
 	case OOR:
 	case OXOR:
 	case OADD:
-	case OADDPTR:
 	case OMUL:
 		a = optoas(n->op, nl->type);
 		if(a == AIMULB) {
@@ -752,12 +751,7 @@ agenr(Node *n, Node *a, Node *res)
 			regalloc(&n3, types[tptr], res);
 			p1 = gins(ALEAQ, N, &n3);
 			datastring(nl->val.u.sval->s, nl->val.u.sval->len, &p1->from);
-			if(flag_largemodel) {
-				gins(AADDQ, &n2, &n3);
-			} else {
-				p1->from.scale = 1;
-				p1->from.index = n2.val.u.reg;
-			}
+			gins(AADDQ, &n2, &n3);
 			goto indexdone;
 		}
 
diff --git a/src/cmd/6g/gg.h b/src/cmd/6g/gg.h
index a5da17d61..27f6c01fe 100644
--- a/src/cmd/6g/gg.h
+++ b/src/cmd/6g/gg.h
@@ -51,7 +51,6 @@ void	allocparams(void);
 void	checklabels(void);
 void	ginscall(Node*, int);
 int	gen_as_init(Node*);
-void	clearslim(Node*);
 
 /*
  * cgen.c
diff --git a/src/cmd/6g/ggen.c b/src/cmd/6g/ggen.c
index c385798f2..9665d831b 100644
--- a/src/cmd/6g/ggen.c
+++ b/src/cmd/6g/ggen.c
@@ -943,7 +943,7 @@ cgen_hmul(Node *nl, Node *nr, Node *res)
 	if(t->width == 1) {
 		// byte multiply behaves differently.
 		nodreg(&ax, t, D_AH);
-		nodreg(&dx, t, D_DL);
+		nodreg(&dx, t, D_DX);
 		gmove(&ax, &dx);
 	}
 	nodreg(&dx, t, D_DX);
diff --git a/src/cmd/6g/gsubr.c b/src/cmd/6g/gsubr.c
index f3464b7e1..a451d7d62 100644
--- a/src/cmd/6g/gsubr.c
+++ b/src/cmd/6g/gsubr.c
@@ -598,11 +598,8 @@ ismem(Node *n)
 	case ONAME:
 	case OPARAM:
 	case OCLOSUREVAR:
-		return 1;
 	case OADDR:
-		if(flag_largemodel)
-			return 1;
-		break;
+		return 1;
 	}
 	return 0;
 }
@@ -1540,14 +1537,12 @@ optoas(int op, Type *t)
 	case CASE(OADD, TINT32):
 	case CASE(OADD, TUINT32):
 	case CASE(OADD, TPTR32):
-	case CASE(OADDPTR, TPTR32):
 		a = AADDL;
 		break;
 
 	case CASE(OADD, TINT64):
 	case CASE(OADD, TUINT64):
 	case CASE(OADD, TPTR64):
-	case CASE(OADDPTR, TPTR64):
 		a = AADDQ;
 		break;
 
diff --git a/src/cmd/6g/peep.c b/src/cmd/6g/peep.c
index 0f2720443..24617836f 100644
--- a/src/cmd/6g/peep.c
+++ b/src/cmd/6g/peep.c
@@ -838,6 +838,11 @@ copyu(Prog *p, Adr *v, Adr *s)
 static int
 copyas(Adr *a, Adr *v)
 {
+	if(D_AL <= a->type && a->type <= D_R15B)
+		fatal("use of byte register");
+	if(D_AL <= v->type && v->type <= D_R15B)
+		fatal("use of byte register");
+
 	if(a->type != v->type)
 		return 0;
 	if(regtyp(v))
diff --git a/src/cmd/6g/reg.c b/src/cmd/6g/reg.c
index 02945fb40..1f757e197 100644
--- a/src/cmd/6g/reg.c
+++ b/src/cmd/6g/reg.c
@@ -844,7 +844,7 @@ prop(Reg *r, Bits ref, Bits cal)
 					if(v == v1 || ((cal.b[j/32]>>(j&31))&1) == 0) {
 						for(; v1 != nil; v1 = v1->nextinnode) {
 							j = v1 - var;
-							cal.b[j/32] |= 1<<(j&31);
+							cal.b[j/32] |= 1UL<<(j&31);
 						}
 					}
 				}
@@ -1191,6 +1191,7 @@ void
 addreg(Adr *a, int rn)
 {
 	a->sym = nil;
+	a->node = nil;
 	a->offset = 0;
 	a->type = rn;
 
diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c
index e251e32ca..18b5aa311 100644
--- a/src/cmd/6l/asm.c
+++ b/src/cmd/6l/asm.c
@@ -290,7 +290,6 @@ elfreloc1(Reloc *r, vlong sectoff)
 		break;
 		
 	case R_CALL:
-	case R_PCREL:
 		if(r->siz == 4) {
 			if(r->xsym->type == SDYNIMPORT)
 				VPUT(R_X86_64_GOTPCREL | (uint64)elfsym<<32);
@@ -299,7 +298,14 @@ elfreloc1(Reloc *r, vlong sectoff)
 		} else
 			return -1;
 		break;
-	
+
+	case R_PCREL:
+		if(r->siz == 4) {
+			VPUT(R_X86_64_PC32 | (uint64)elfsym<<32);
+		} else
+			return -1;
+		break;
+
 	case R_TLS:
 		if(r->siz == 4) {
 			if(flag_shared)
@@ -323,7 +329,7 @@ machoreloc1(Reloc *r, vlong sectoff)
 	
 	rs = r->xsym;
 
-	if(rs->type == SHOSTOBJ) {
+	if(rs->type == SHOSTOBJ || r->type == R_PCREL) {
 		if(rs->dynid < 0) {
 			diag("reloc %d to non-macho symbol %s type=%d", r->type, rs->name, rs->type);
 			return -1;
@@ -345,10 +351,13 @@ machoreloc1(Reloc *r, vlong sectoff)
 		v |= MACHO_X86_64_RELOC_UNSIGNED<<28;
 		break;
 	case R_CALL:
-	case R_PCREL:
 		v |= 1<<24; // pc-relative bit
 		v |= MACHO_X86_64_RELOC_BRANCH<<28;
 		break;
+	case R_PCREL:
+		// NOTE: Only works with 'external' relocation. Forced above.
+		v |= 1<<24; // pc-relative bit
+		v |= MACHO_X86_64_RELOC_SIGNED<<28;
 	}
 	
 	switch(r->siz) {
@@ -689,10 +698,10 @@ asmb(void)
 		case Hplan9:
 		case Helf:
 			debug['s'] = 1;
-			symo = HEADR+segtext.len+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			break;
 		case Hdarwin:
-			symo = rnd(HEADR+segtext.len, INITRND)+rnd(segdata.filelen, INITRND)+machlink;
+			symo = segdata.fileoff+rnd(segdata.filelen, INITRND)+machlink;
 			break;
 		case Hlinux:
 		case Hfreebsd:
@@ -701,11 +710,11 @@ asmb(void)
 		case Hdragonfly:
 		case Hsolaris:
 		case Hnacl:
-			symo = rnd(HEADR+segtext.len, INITRND)+rnd(segrodata.len, INITRND)+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			symo = rnd(symo, INITRND);
 			break;
 		case Hwindows:
-			symo = rnd(HEADR+segtext.filelen, PEFILEALIGN)+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			symo = rnd(symo, PEFILEALIGN);
 			break;
 		}
diff --git a/src/cmd/8a/lex.c b/src/cmd/8a/lex.c
index 32c099b75..807e48cb5 100644
--- a/src/cmd/8a/lex.c
+++ b/src/cmd/8a/lex.c
@@ -352,49 +352,49 @@ struct
 	"IRETL",	LTYPE0,	AIRETL,
 	"IRETW",	LTYPE0,	AIRETW,
 
-	"JOS",		LTYPER,	AJOS,
+	"JOS",		LTYPER,	AJOS,	/* overflow set (OF = 1) */
 	"JO",		LTYPER,	AJOS,	/* alternate */
-	"JOC",		LTYPER,	AJOC,
+	"JOC",		LTYPER,	AJOC,	/* overflow clear (OF = 0) */
 	"JNO",		LTYPER,	AJOC,	/* alternate */
-	"JCS",		LTYPER,	AJCS,
+	"JCS",		LTYPER,	AJCS,	/* carry set (CF = 1) */
 	"JB",		LTYPER,	AJCS,	/* alternate */
 	"JC",		LTYPER,	AJCS,	/* alternate */
 	"JNAE",		LTYPER,	AJCS,	/* alternate */
 	"JLO",		LTYPER,	AJCS,	/* alternate */
-	"JCC",		LTYPER,	AJCC,
+	"JCC",		LTYPER,	AJCC,	/* carry clear (CF = 0) */
 	"JAE",		LTYPER,	AJCC,	/* alternate */
 	"JNB",		LTYPER,	AJCC,	/* alternate */
 	"JNC",		LTYPER,	AJCC,	/* alternate */
 	"JHS",		LTYPER,	AJCC,	/* alternate */
-	"JEQ",		LTYPER,	AJEQ,
+	"JEQ",		LTYPER,	AJEQ,	/* equal (ZF = 1) */
 	"JE",		LTYPER,	AJEQ,	/* alternate */
 	"JZ",		LTYPER,	AJEQ,	/* alternate */
-	"JNE",		LTYPER,	AJNE,
+	"JNE",		LTYPER,	AJNE,	/* not equal (ZF = 0) */
 	"JNZ",		LTYPER,	AJNE,	/* alternate */
-	"JLS",		LTYPER,	AJLS,
+	"JLS",		LTYPER,	AJLS,	/* lower or same (unsigned) (CF = 1 || ZF = 1) */
 	"JBE",		LTYPER,	AJLS,	/* alternate */
 	"JNA",		LTYPER,	AJLS,	/* alternate */
-	"JHI",		LTYPER,	AJHI,
+	"JHI",		LTYPER,	AJHI,	/* higher (unsigned) (CF = 0 && ZF = 0) */
 	"JA",		LTYPER,	AJHI,	/* alternate */
 	"JNBE",		LTYPER,	AJHI,	/* alternate */
-	"JMI",		LTYPER,	AJMI,
+	"JMI",		LTYPER,	AJMI,	/* negative (minus) (SF = 1) */
 	"JS",		LTYPER,	AJMI,	/* alternate */
-	"JPL",		LTYPER,	AJPL,
+	"JPL",		LTYPER,	AJPL,	/* non-negative (plus) (SF = 0) */
 	"JNS",		LTYPER,	AJPL,	/* alternate */
-	"JPS",		LTYPER,	AJPS,
+	"JPS",		LTYPER,	AJPS,	/* parity set (PF = 1) */
 	"JP",		LTYPER,	AJPS,	/* alternate */
 	"JPE",		LTYPER,	AJPS,	/* alternate */
-	"JPC",		LTYPER,	AJPC,
+	"JPC",		LTYPER,	AJPC,	/* parity clear (PF = 0) */
 	"JNP",		LTYPER,	AJPC,	/* alternate */
 	"JPO",		LTYPER,	AJPC,	/* alternate */
-	"JLT",		LTYPER,	AJLT,
+	"JLT",		LTYPER,	AJLT,	/* less than (signed) (SF != OF) */
 	"JL",		LTYPER,	AJLT,	/* alternate */
 	"JNGE",		LTYPER,	AJLT,	/* alternate */
-	"JGE",		LTYPER,	AJGE,
+	"JGE",		LTYPER,	AJGE,	/* greater than or equal (signed) (SF = OF) */
 	"JNL",		LTYPER,	AJGE,	/* alternate */
-	"JLE",		LTYPER,	AJLE,
+	"JLE",		LTYPER,	AJLE,	/* less than or equal (signed) (ZF = 1 || SF != OF) */
 	"JNG",		LTYPER,	AJLE,	/* alternate */
-	"JGT",		LTYPER,	AJGT,
+	"JGT",		LTYPER,	AJGT,	/* greater than (signed) (ZF = 0 && SF = OF) */
 	"JG",		LTYPER,	AJGT,	/* alternate */
 	"JNLE",		LTYPER,	AJGT,	/* alternate */
 
@@ -493,7 +493,7 @@ struct
 	"SCASB",	LTYPE0,	ASCASB,
 	"SCASL",	LTYPE0,	ASCASL,
 	"SCASW",	LTYPE0,	ASCASW,
-	"SETCC",	LTYPE1,	ASETCC,
+	"SETCC",	LTYPE1,	ASETCC,	/* see JCC etc above for condition codes */
 	"SETCS",	LTYPE1,	ASETCS,
 	"SETEQ",	LTYPE1,	ASETEQ,
 	"SETGE",	LTYPE1,	ASETGE,
diff --git a/src/cmd/8c/cgen.c b/src/cmd/8c/cgen.c
index f54102245..8ac8e3600 100644
--- a/src/cmd/8c/cgen.c
+++ b/src/cmd/8c/cgen.c
@@ -49,7 +49,7 @@ cgen(Node *n, Node *nn)
 	}
 	if(n == Z || n->type == T)
 		return;
-	if(typesuv[n->type->etype]) {
+	if(typesuv[n->type->etype] && (n->op != OFUNC || nn != Z)) {
 		sugen(n, nn, n->type->width);
 		return;
 	}
@@ -86,7 +86,7 @@ cgen(Node *n, Node *nn)
 		if(cond(o) && typesuv[l->type->etype])
 			break;
 
-		regret(&nod, r);
+		regret(&nod, r, 0, 0);
 		cgen(r, &nod);
 
 		regsalloc(&nod1, r);
@@ -147,7 +147,7 @@ cgen(Node *n, Node *nn)
 		if(!hardleft) {
 			if(nn != Z || r->addable < INDEXED) {
 				if(r->complex >= FNX && nn == Z)
-					regret(&nod, r);
+					regret(&nod, r, 0, 0);
 				else
 					regalloc(&nod, r, nn);
 				cgen(r, &nod);
@@ -922,7 +922,7 @@ cgen(Node *n, Node *nn)
 			if(l->op != OIND)
 				diag(n, "bad function call");
 
-			regret(&nod, l->left);
+			regret(&nod, l->left, 0, 0);
 			cgen(l->left, &nod);
 			regsalloc(&nod1, l->left);
 			gmove(&nod, &nod1);
@@ -949,12 +949,12 @@ cgen(Node *n, Node *nn)
 		gpcdata(PCDATA_ArgSize, -1);
 		if(REGARG >= 0 && reg[REGARG])
 			reg[REGARG]--;
-		if(nn != Z) {
-			regret(&nod, n);
+		regret(&nod, n, l->type, 1); // update maxarg if nothing else
+		if(nn != Z)
 			gmove(&nod, nn);
+		if(nod.op == OREGISTER)
 			regfree(&nod);
-		} else
-		if(typefd[n->type->etype])
+		if(nn == Z && hasdotdotdot(l->type) && typefd[n->type->etype])
 			gins(AFMOVDP, &fregnode0, &fregnode0);
 		break;
 
@@ -1374,7 +1374,7 @@ boolgen(Node *n, int true, Node *nn)
 		if(true)
 			o = comrel[relindex(o)];
 		if(l->complex >= FNX && r->complex >= FNX) {
-			regret(&nod, r);
+			regret(&nod, r, 0, 0);
 			cgen(r, &nod);
 			regsalloc(&nod1, r);
 			gmove(&nod, &nod1);
@@ -1567,7 +1567,7 @@ sugen(Node *n, Node *nn, int32 w)
 		if(nn != Z && side(nn)) {
 			nod1 = *n;
 			nod1.type = typ(TIND, n->type);
-			regret(&nod2, &nod1);
+			regret(&nod2, &nod1, 0, 0);
 			lcgen(nn, &nod2);
 			regsalloc(&nod0, &nod1);
 			cgen(&nod2, &nod0);
@@ -1649,6 +1649,20 @@ sugen(Node *n, Node *nn, int32 w)
 		break;
 
 	case OFUNC:
+		if(!hasdotdotdot(n->left->type)) {
+			cgen(n, Z);
+			if(nn != Z) {
+				curarg -= n->type->width;
+				regret(&nod1, n, n->left->type, 1);
+				if(nn->complex >= FNX) {
+					regsalloc(&nod2, n);
+					cgen(&nod1, &nod2);
+					nod1 = nod2;
+				}
+				cgen(&nod1, nn);
+			}
+			break;
+		}
 		if(nn == Z) {
 			sugen(n, nodrat, w);
 			break;
diff --git a/src/cmd/8c/gc.h b/src/cmd/8c/gc.h
index 9c4613f56..aa3888d73 100644
--- a/src/cmd/8c/gc.h
+++ b/src/cmd/8c/gc.h
@@ -210,7 +210,7 @@ void	xcom(Node*);
 void	indx(Node*);
 int	bcomplex(Node*, Node*);
 Prog*	gtext(Sym*, int32);
-vlong	argsize(void);
+vlong	argsize(int);
 
 /*
  * cgen.c
@@ -244,7 +244,7 @@ Node*	nodconst(int32);
 Node*	nodfconst(double);
 int	nodreg(Node*, Node*, int);
 int	isreg(Node*, int);
-void	regret(Node*, Node*);
+void	regret(Node*, Node*, Type*, int);
 void	regalloc(Node*, Node*, Node*);
 void	regfree(Node*);
 void	regialloc(Node*, Node*, Node*);
diff --git a/src/cmd/8c/sgen.c b/src/cmd/8c/sgen.c
index 069bbc1fc..d647010ef 100644
--- a/src/cmd/8c/sgen.c
+++ b/src/cmd/8c/sgen.c
@@ -35,7 +35,7 @@ gtext(Sym *s, int32 stkoff)
 {
 	int32 a;
 
-	a = argsize();
+	a = argsize(1);
 	if((textflag & NOSPLIT) != 0 && stkoff >= 128)
 		yyerror("stack frame too large for NOSPLIT function");
 
diff --git a/src/cmd/8c/swt.c b/src/cmd/8c/swt.c
index ae36f84ea..d960519e3 100644
--- a/src/cmd/8c/swt.c
+++ b/src/cmd/8c/swt.c
@@ -255,10 +255,11 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 {
 	int32 o;
 	Type *v;
-	int w;
+	int w, packw;
 
 	o = i;
 	w = 1;
+	packw = 0;
 	switch(op) {
 	default:
 		diag(Z, "unknown align opcode %d", op);
@@ -269,7 +270,7 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		if(w < 1)
 			w = 1;
 		if(packflg)
-			w = packflg;
+			packw = packflg;
 		break;
 
 	case Ael1:	/* initial align of struct element */
@@ -285,7 +286,7 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		if(w < 1 || w > SZ_LONG)
 			fatal(Z, "align");
 		if(packflg) 
-			w = packflg;
+			packw = packflg;
 		break;
 
 	case Ael2:	/* width of a struct element */
@@ -320,6 +321,8 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		o = align(o, t, Ael2, nil);
 		break;
 	}
+	if(packw != 0 && xround(o, w) != xround(o, packw))
+		diag(Z, "#pragma pack changes offset of %T", t);
 	o = xround(o, w);
 	if(maxalign && *maxalign < w)
 		*maxalign = w;
diff --git a/src/cmd/8c/txt.c b/src/cmd/8c/txt.c
index 25082de05..7f87a0a0d 100644
--- a/src/cmd/8c/txt.c
+++ b/src/cmd/8c/txt.c
@@ -311,15 +311,43 @@ nodreg(Node *n, Node *nn, int r)
 }
 
 void
-regret(Node *n, Node *nn)
+regret(Node *n, Node *nn, Type *t, int mode)
 {
 	int r;
 
-	r = REGRET;
-	if(typefd[nn->type->etype])
-		r = FREGRET;
-	nodreg(n, nn, r);
-	reg[r]++;
+	if(mode == 0 || hasdotdotdot(t) || nn->type->width == 0) {
+		r = REGRET;
+		if(typefd[nn->type->etype])
+			r = FREGRET;
+		nodreg(n, nn, r);
+		reg[r]++;
+		return;
+	}
+	
+	if(mode == 1) {
+		// fetch returned value after call.
+		// already called gargs, so curarg is set.
+		curarg = (curarg+3) & ~3;
+		regaalloc(n, nn);
+		return;
+	}
+	
+	if(mode == 2) {
+		// store value to be returned.
+		// must compute arg offset.
+		if(t->etype != TFUNC)
+			fatal(Z, "bad regret func %T", t);
+		*n = *nn;
+		n->op = ONAME;
+		n->class = CPARAM;
+		n->sym = slookup(".retx");
+		n->complex = 0;
+		n->addable = 20;
+		n->xoffset = argsize(0);
+		return;
+	}
+	
+	fatal(Z, "bad regret");
 }
 
 void
diff --git a/src/cmd/8g/cgen.c b/src/cmd/8g/cgen.c
index 5988a4328..f3093bc26 100644
--- a/src/cmd/8g/cgen.c
+++ b/src/cmd/8g/cgen.c
@@ -242,7 +242,6 @@ cgen(Node *n, Node *res)
 	case OOR:
 	case OXOR:
 	case OADD:
-	case OADDPTR:
 	case OMUL:
 		a = optoas(n->op, nl->type);
 		if(a == AIMULB) {
@@ -1367,7 +1366,10 @@ int
 componentgen(Node *nr, Node *nl)
 {
 	Node nodl, nodr;
+	Type *t;
 	int freel, freer;
+	vlong fldcount;
+	vlong loffset, roffset;
 
 	freel = 0;
 	freer = 0;
@@ -1377,8 +1379,33 @@ componentgen(Node *nr, Node *nl)
 		goto no;
 
 	case TARRAY:
-		if(!isslice(nl->type))
+		t = nl->type;
+
+		// Slices are ok.
+		if(isslice(t))
+			break;
+		// Small arrays are ok.
+		if(t->bound > 0 && t->bound <= 3 && !isfat(t->type))
+			break;
+
+		goto no;
+
+	case TSTRUCT:
+		// Small structs with non-fat types are ok.
+		// Zero-sized structs are treated separately elsewhere.
+		fldcount = 0;
+		for(t=nl->type->type; t; t=t->down) {
+			if(isfat(t->type))
+				goto no;
+			if(t->etype != TFIELD)
+				fatal("componentgen: not a TFIELD: %lT", t);
+			fldcount++;
+		}
+		if(fldcount == 0 || fldcount > 4)
 			goto no;
+
+		break;
+
 	case TSTRING:
 	case TINTER:
 		break;
@@ -1399,7 +1426,7 @@ componentgen(Node *nr, Node *nl)
 			freer = 1;
 		}
 	}
-
+	
 	// nl and nr are 'cadable' which basically means they are names (variables) now.
 	// If they are the same variable, don't generate any code, because the
 	// VARDEF we generate will mark the old value as dead incorrectly.
@@ -1409,8 +1436,25 @@ componentgen(Node *nr, Node *nl)
 
 	switch(nl->type->etype) {
 	case TARRAY:
+		// componentgen for arrays.
 		if(nl->op == ONAME)
 			gvardef(nl);
+		t = nl->type;
+		if(!isslice(t)) {
+			nodl.type = t->type;
+			nodr.type = nodl.type;
+			for(fldcount=0; fldcount < t->bound; fldcount++) {
+				if(nr == N)
+					clearslim(&nodl);
+				else
+					gmove(&nodr, &nodl);
+				nodl.xoffset += t->type->width;
+				nodr.xoffset += t->type->width;
+			}
+			goto yes;
+		}
+
+		// componentgen for slices.
 		nodl.xoffset += Array_array;
 		nodl.type = ptrto(nl->type->type);
 
@@ -1422,7 +1466,7 @@ componentgen(Node *nr, Node *nl)
 		gmove(&nodr, &nodl);
 
 		nodl.xoffset += Array_nel-Array_array;
-		nodl.type = types[TUINT32];
+		nodl.type = types[simtype[TUINT]];
 
 		if(nr != N) {
 			nodr.xoffset += Array_nel-Array_array;
@@ -1432,7 +1476,7 @@ componentgen(Node *nr, Node *nl)
 		gmove(&nodr, &nodl);
 
 		nodl.xoffset += Array_cap-Array_nel;
-		nodl.type = types[TUINT32];
+		nodl.type = types[simtype[TUINT]];
 
 		if(nr != N) {
 			nodr.xoffset += Array_cap-Array_nel;
@@ -1457,7 +1501,7 @@ componentgen(Node *nr, Node *nl)
 		gmove(&nodr, &nodl);
 
 		nodl.xoffset += Array_nel-Array_array;
-		nodl.type = types[TUINT32];
+		nodl.type = types[simtype[TUINT]];
 
 		if(nr != N) {
 			nodr.xoffset += Array_nel-Array_array;
@@ -1492,6 +1536,31 @@ componentgen(Node *nr, Node *nl)
 		gmove(&nodr, &nodl);
 
 		goto yes;
+
+	case TSTRUCT:
+		if(nl->op == ONAME)
+			gvardef(nl);
+		loffset = nodl.xoffset;
+		roffset = nodr.xoffset;
+		// funarg structs may not begin at offset zero.
+		if(nl->type->etype == TSTRUCT && nl->type->funarg && nl->type->type)
+			loffset -= nl->type->type->width;
+		if(nr != N && nr->type->etype == TSTRUCT && nr->type->funarg && nr->type->type)
+			roffset -= nr->type->type->width;
+
+		for(t=nl->type->type; t; t=t->down) {
+			nodl.xoffset = loffset + t->width;
+			nodl.type = t->type;
+
+			if(nr == N)
+				clearslim(&nodl);
+			else {
+				nodr.xoffset = roffset + t->width;
+				nodr.type = nodl.type;
+				gmove(&nodr, &nodl);
+			}
+		}
+		goto yes;
 	}
 
 no:
diff --git a/src/cmd/8g/ggen.c b/src/cmd/8g/ggen.c
index 2285a04e6..5e3140480 100644
--- a/src/cmd/8g/ggen.c
+++ b/src/cmd/8g/ggen.c
@@ -991,7 +991,7 @@ cgen_hmul(Node *nl, Node *nr, Node *res)
 	if(t->width == 1) {
 		// byte multiply behaves differently.
 		nodreg(&ax, t, D_AH);
-		nodreg(&dx, t, D_DL);
+		nodreg(&dx, t, D_DX);
 		gmove(&ax, &dx);
 	}
 	nodreg(&dx, t, D_DX);
diff --git a/src/cmd/8g/gsubr.c b/src/cmd/8g/gsubr.c
index 66d5b8d69..9ee418cb7 100644
--- a/src/cmd/8g/gsubr.c
+++ b/src/cmd/8g/gsubr.c
@@ -430,7 +430,6 @@ optoas(int op, Type *t)
 	case CASE(OADD, TINT32):
 	case CASE(OADD, TUINT32):
 	case CASE(OADD, TPTR32):
-	case CASE(OADDPTR, TPTR32):
 		a = AADDL;
 		break;
 
diff --git a/src/cmd/8g/peep.c b/src/cmd/8g/peep.c
index d88987f95..91a91d20d 100644
--- a/src/cmd/8g/peep.c
+++ b/src/cmd/8g/peep.c
@@ -636,6 +636,11 @@ copyu(Prog *p, Adr *v, Adr *s)
 static int
 copyas(Adr *a, Adr *v)
 {
+	if(D_AL <= a->type && a->type <= D_BL)
+		fatal("use of byte register");
+	if(D_AL <= v->type && v->type <= D_BL)
+		fatal("use of byte register");
+
 	if(a->type != v->type)
 		return 0;
 	if(regtyp(v))
diff --git a/src/cmd/8g/reg.c b/src/cmd/8g/reg.c
index a69d124db..302b273a1 100644
--- a/src/cmd/8g/reg.c
+++ b/src/cmd/8g/reg.c
@@ -1168,6 +1168,7 @@ void
 addreg(Adr *a, int rn)
 {
 	a->sym = nil;
+	a->node = nil;
 	a->offset = 0;
 	a->type = rn;
 
diff --git a/src/cmd/8l/asm.c b/src/cmd/8l/asm.c
index 114a3eb5d..c135dce70 100644
--- a/src/cmd/8l/asm.c
+++ b/src/cmd/8l/asm.c
@@ -619,17 +619,17 @@ asmb(void)
 			if(iself)
 				goto Elfsym;
 		case Hplan9:
-			symo = HEADR+segtext.filelen+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			break;
 		case Hdarwin:
-			symo = rnd(HEADR+segtext.filelen, INITRND)+rnd(segdata.filelen, INITRND)+machlink;
+			symo = segdata.fileoff+rnd(segdata.filelen, INITRND)+machlink;
 			break;
 		Elfsym:
-			symo = rnd(HEADR+segtext.filelen, INITRND)+rnd(HEADR+segrodata.filelen, INITRND)+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			symo = rnd(symo, INITRND);
 			break;
 		case Hwindows:
-			symo = rnd(HEADR+segtext.filelen, PEFILEALIGN)+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			symo = rnd(symo, PEFILEALIGN);
 			break;
 		}
diff --git a/src/cmd/9c/cgen.c b/src/cmd/9c/cgen.c
index 0d7a40294..aeedc60c0 100644
--- a/src/cmd/9c/cgen.c
+++ b/src/cmd/9c/cgen.c
@@ -45,7 +45,7 @@ cgen(Node *n, Node *nn)
 	}
 	if(n == Z || n->type == T)
 		return;
-	if(typesu[n->type->etype]) {
+	if(typesu[n->type->etype] && (n->op != OFUNC || nn != Z)) {
 		sugen(n, nn, n->type->width);
 		return;
 	}
@@ -74,7 +74,7 @@ cgen(Node *n, Node *nn)
 	if(r != Z && r->complex >= FNX)
 	switch(o) {
 	default:
-		regret(&nod, r);
+		regret(&nod, r, 0, 0);
 		cgen(r, &nod);
 
 		regsalloc(&nod1, r);
@@ -324,7 +324,7 @@ cgen(Node *n, Node *nn)
 			if(l->op != OIND)
 				diag(n, "bad function call");
 
-			regret(&nod, l->left);
+			regret(&nod, l->left, 0, 0);
 			cgen(l->left, &nod);
 			regsalloc(&nod1, l->left);
 			gopcode(OAS, &nod, Z, &nod1);
@@ -353,11 +353,13 @@ cgen(Node *n, Node *nn)
 		if(REGARG>=0)
 			if(o != reg[REGARG])
 				reg[REGARG]--;
-		if(nn != Z) {
-			regret(&nod, n);
+		regret(&nod, n, l->type, 1); // update maxarg if nothing else
+		gpcdata(PCDATA_ArgSize, curarg);
+		gpcdata(PCDATA_ArgSize, -1);
+		if(nn != Z)
 			gopcode(OAS, &nod, Z, nn);
+		if(nod.op == OREGISTER)
 			regfree(&nod);
-		}
 		break;
 
 	case OIND:
@@ -759,7 +761,7 @@ boolgen(Node *n, int true, Node *nn)
 		if(true)
 			o = comrel[relindex(o)];
 		if(l->complex >= FNX && r->complex >= FNX) {
-			regret(&nod, r);
+			regret(&nod, r, 0, 0);
 			cgen(r, &nod);
 			regsalloc(&nod1, r);
 			gopcode(OAS, &nod, Z, &nod1);
@@ -966,6 +968,20 @@ sugen(Node *n, Node *nn, int32 w)
 		break;
 
 	case OFUNC:
+		if(!hasdotdotdot(n->left->type)) {
+			cgen(n, Z);
+			if(nn != Z) {
+				curarg -= n->type->width;
+				regret(&nod1, n, n->left->type, 1);
+				if(nn->complex >= FNX) {
+					regsalloc(&nod2, n);
+					cgen(&nod1, &nod2);
+					nod1 = nod2;
+				}
+				cgen(&nod1, nn);
+			}
+			break;
+		}
 		if(nn == Z) {
 			sugen(n, nodrat, w);
 			break;
diff --git a/src/cmd/9c/gc.h b/src/cmd/9c/gc.h
index 82204902b..fbe5099fe 100644
--- a/src/cmd/9c/gc.h
+++ b/src/cmd/9c/gc.h
@@ -141,7 +141,6 @@ extern	int	hintabsize;
 EXTERN	int32	maxargsafe;
 EXTERN	Multab	multab[20];
 EXTERN	int	mnstring;
-EXTERN	int	retok;
 EXTERN	Node*	nodrat;
 EXTERN	Node*	nodret;
 EXTERN	Node*	nodsafe;
@@ -212,7 +211,7 @@ void	noretval(int);
 void	xcom(Node*);
 int	bcomplex(Node*, Node*);
 Prog*	gtext(Sym*, int32);
-vlong	argsize(void);
+vlong	argsize(int);
 
 /*
  * cgen.c
@@ -238,7 +237,7 @@ Node*	nod32const(vlong);
 Node*	nodfconst(double);
 Node*	nodgconst(vlong v, Type *t);
 void	nodreg(Node*, Node*, int);
-void	regret(Node*, Node*);
+void	regret(Node*, Node*, Type*, int);
 void	regalloc(Node*, Node*, Node*);
 void	regfree(Node*);
 void	regialloc(Node*, Node*, Node*);
diff --git a/src/cmd/9c/sgen.c b/src/cmd/9c/sgen.c
index 25f0438e5..b03c17267 100644
--- a/src/cmd/9c/sgen.c
+++ b/src/cmd/9c/sgen.c
@@ -34,7 +34,7 @@ gtext(Sym *s, int32 stkoff)
 {
 	vlong v;
 
-	v = ((uvlong)argsize() << 32) | (stkoff & 0xffffffff);
+	v = ((uvlong)argsize(1) << 32) | (stkoff & 0xffffffff);
 	if((textflag & NOSPLIT) && stkoff >= 128)
 		yyerror("stack frame too large for NOSPLIT function");
 
diff --git a/src/cmd/9c/swt.c b/src/cmd/9c/swt.c
index 83058e7ab..a63db60b2 100644
--- a/src/cmd/9c/swt.c
+++ b/src/cmd/9c/swt.c
@@ -324,10 +324,11 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 {
 	int32 o;
 	Type *v;
-	int w;
+	int w, packw;
 
 	o = i;
 	w = 1;
+	packw = 0;
 	switch(op) {
 	default:
 		diag(Z, "unknown align opcode %d", op);
@@ -338,7 +339,7 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		if(w < 1)
 			w = 1;
 		if(packflg)
-			w = packflg;
+			packw = packflg;
 		break;
 
 	case Ael1:	/* initial allign of struct element */
@@ -351,7 +352,7 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		if(w < 1 || w > SZ_VLONG)
 			fatal(Z, "align");
 		if(packflg)
-			w = packflg;
+			packw = packflg;
 		break;
 
 	case Ael2:	/* width of a struct element */
@@ -386,6 +387,8 @@ align(int32 i, Type *t, int op, int32 *maxalign)
 		o = align(o, t, Ael2, nil);
 		break;
 	}
+	if(packw != 0 && xround(o, w) != xround(o, packw))
+		diag(Z, "#pragma pack changes offset of %T", t);
 	o = xround(o, w);
 	if(maxalign && *maxalign < w)
 		*maxalign = w;
diff --git a/src/cmd/9c/txt.c b/src/cmd/9c/txt.c
index 84aeb4d8a..e46aba84e 100644
--- a/src/cmd/9c/txt.c
+++ b/src/cmd/9c/txt.c
@@ -319,15 +319,43 @@ nodreg(Node *n, Node *nn, int reg)
 }
 
 void
-regret(Node *n, Node *nn)
+regret(Node *n, Node *nn, Type *t, int mode)
 {
 	int r;
+	
+	if(mode == 0 || hasdotdotdot(t) || nn->type->width == 0) {
+		r = REGRET;
+		if(typefd[nn->type->etype])
+			r = FREGRET+NREG;
+		nodreg(n, nn, r);
+		reg[r]++;
+		return;
+	}
+	
+	if(mode == 1) {
+		// fetch returned value after call.
+		// already called gargs, so curarg is set.
+		curarg = (curarg+7) & ~7;
+		regaalloc(n, nn);
+		return;
+	}
 
-	r = REGRET;
-	if(typefd[nn->type->etype])
-		r = FREGRET+NREG;
-	nodreg(n, nn, r);
-	reg[r]++;
+	if(mode == 2) {
+		// store value to be returned.
+		// must compute arg offset.
+		if(t->etype != TFUNC)
+			fatal(Z, "bad regret func %T", t);
+		*n = *nn;
+		n->op = ONAME;
+		n->class = CPARAM;
+		n->sym = slookup(".ret");
+		n->complex = nodret->complex;
+		n->addable = 20;
+		n->xoffset = argsize(0);
+		return;
+	}
+	
+	fatal(Z, "bad regret");	
 }
 
 void
diff --git a/src/cmd/9g/cgen.c b/src/cmd/9g/cgen.c
index 86a56975a..e38936001 100644
--- a/src/cmd/9g/cgen.c
+++ b/src/cmd/9g/cgen.c
@@ -260,7 +260,6 @@ cgen(Node *n, Node *res)
 	case OOR:
 	case OXOR:
 	case OADD:
-	case OADDPTR:
 	case OMUL:
 		a = optoas(n->op, nl->type);
 		goto sbop;
diff --git a/src/cmd/9g/gg.h b/src/cmd/9g/gg.h
index 6aa00117f..2eb516b40 100644
--- a/src/cmd/9g/gg.h
+++ b/src/cmd/9g/gg.h
@@ -49,7 +49,6 @@ void	allocparams(void);
 void	checklabels(void);
 void	ginscall(Node*, int);
 int	gen_as_init(Node*);
-void	clearslim(Node*);
 
 /*
  * cgen.c
diff --git a/src/cmd/9g/gsubr.c b/src/cmd/9g/gsubr.c
index dfdff0587..b194cfd9e 100644
--- a/src/cmd/9g/gsubr.c
+++ b/src/cmd/9g/gsubr.c
@@ -614,11 +614,8 @@ ismem(Node *n)
 	case ONAME:
 	case OPARAM:
 	case OCLOSUREVAR:
-		return 1;
 	case OADDR:
-		//if(flag_largemodel)
-			return 1;
-		break;
+		return 1;
 	}
 	return 0;
 }
@@ -1474,11 +1471,9 @@ optoas(int op, Type *t)
 	case CASE(OADD, TINT32):
 	case CASE(OADD, TUINT32):
 	case CASE(OADD, TPTR32):
-	case CASE(OADDPTR, TPTR32):
 	case CASE(OADD, TINT64):
 	case CASE(OADD, TUINT64):
 	case CASE(OADD, TPTR64):
-	case CASE(OADDPTR, TPTR64):
 		a = AADD;
 		break;
 
diff --git a/src/cmd/9l/asm.c b/src/cmd/9l/asm.c
index 5aeea1b6b..b8ca777c3 100644
--- a/src/cmd/9l/asm.c
+++ b/src/cmd/9l/asm.c
@@ -245,10 +245,10 @@ asmb(void)
 			if(iself)
 				goto ElfSym;
 		case Hplan9:
-			symo = HEADR+segtext.len+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			break;
 		ElfSym:
-			symo = rnd(HEADR+segtext.filelen, INITRND)+rnd(HEADR+segrodata.filelen, INITRND)+segdata.filelen;
+			symo = segdata.fileoff+segdata.filelen;
 			symo = rnd(symo, INITRND);
 			break;
 		}
diff --git a/src/cmd/addr2line/main.go b/src/cmd/addr2line/main.go
index 3802f764f..267f4170a 100644
--- a/src/cmd/addr2line/main.go
+++ b/src/cmd/addr2line/main.go
@@ -19,17 +19,14 @@ package main
 
 import (
 	"bufio"
-	"debug/elf"
-	"debug/gosym"
-	"debug/macho"
-	"debug/pe"
-	"debug/plan9obj"
 	"flag"
 	"fmt"
 	"log"
 	"os"
 	"strconv"
 	"strings"
+
+	"cmd/internal/objfile"
 )
 
 func printUsage(w *os.File) {
@@ -60,18 +57,12 @@ func main() {
 		usage()
 	}
 
-	f, err := os.Open(flag.Arg(0))
+	f, err := objfile.Open(flag.Arg(0))
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	textStart, symtab, pclntab, err := loadTables(f)
-	if err != nil {
-		log.Fatalf("reading %s: %v", flag.Arg(0), err)
-	}
-
-	pcln := gosym.NewLineTable(pclntab, textStart)
-	tab, err := gosym.NewTable(symtab, pcln)
+	tab, err := f.PCLineTable()
 	if err != nil {
 		log.Fatalf("reading %s: %v", flag.Arg(0), err)
 	}
@@ -102,145 +93,3 @@ func main() {
 	}
 	stdout.Flush()
 }
-
-func loadTables(f *os.File) (textStart uint64, symtab, pclntab []byte, err error) {
-	if obj, err := elf.NewFile(f); err == nil {
-		if sect := obj.Section(".text"); sect != nil {
-			textStart = sect.Addr
-		}
-		if sect := obj.Section(".gosymtab"); sect != nil {
-			if symtab, err = sect.Data(); err != nil {
-				return 0, nil, nil, err
-			}
-		}
-		if sect := obj.Section(".gopclntab"); sect != nil {
-			if pclntab, err = sect.Data(); err != nil {
-				return 0, nil, nil, err
-			}
-		}
-		return textStart, symtab, pclntab, nil
-	}
-
-	if obj, err := macho.NewFile(f); err == nil {
-		if sect := obj.Section("__text"); sect != nil {
-			textStart = sect.Addr
-		}
-		if sect := obj.Section("__gosymtab"); sect != nil {
-			if symtab, err = sect.Data(); err != nil {
-				return 0, nil, nil, err
-			}
-		}
-		if sect := obj.Section("__gopclntab"); sect != nil {
-			if pclntab, err = sect.Data(); err != nil {
-				return 0, nil, nil, err
-			}
-		}
-		return textStart, symtab, pclntab, nil
-	}
-
-	if obj, err := pe.NewFile(f); err == nil {
-		var imageBase uint64
-		switch oh := obj.OptionalHeader.(type) {
-		case *pe.OptionalHeader32:
-			imageBase = uint64(oh.ImageBase)
-		case *pe.OptionalHeader64:
-			imageBase = oh.ImageBase
-		default:
-			return 0, nil, nil, fmt.Errorf("pe file format not recognized")
-		}
-		if sect := obj.Section(".text"); sect != nil {
-			textStart = imageBase + uint64(sect.VirtualAddress)
-		}
-		if pclntab, err = loadPETable(obj, "pclntab", "epclntab"); err != nil {
-			return 0, nil, nil, err
-		}
-		if symtab, err = loadPETable(obj, "symtab", "esymtab"); err != nil {
-			return 0, nil, nil, err
-		}
-		return textStart, symtab, pclntab, nil
-	}
-
-	if obj, err := plan9obj.NewFile(f); err == nil {
-		textStart = obj.LoadAddress + obj.HdrSize
-		if pclntab, err = loadPlan9Table(obj, "pclntab", "epclntab"); err != nil {
-			return 0, nil, nil, err
-		}
-		if symtab, err = loadPlan9Table(obj, "symtab", "esymtab"); err != nil {
-			return 0, nil, nil, err
-		}
-		return textStart, symtab, pclntab, nil
-	}
-
-	return 0, nil, nil, fmt.Errorf("unrecognized binary format")
-}
-
-func findPESymbol(f *pe.File, name string) (*pe.Symbol, error) {
-	for _, s := range f.Symbols {
-		if s.Name != name {
-			continue
-		}
-		if s.SectionNumber <= 0 {
-			return nil, fmt.Errorf("symbol %s: invalid section number %d", name, s.SectionNumber)
-		}
-		if len(f.Sections) < int(s.SectionNumber) {
-			return nil, fmt.Errorf("symbol %s: section number %d is larger than max %d", name, s.SectionNumber, len(f.Sections))
-		}
-		return s, nil
-	}
-	return nil, fmt.Errorf("no %s symbol found", name)
-}
-
-func loadPETable(f *pe.File, sname, ename string) ([]byte, error) {
-	ssym, err := findPESymbol(f, sname)
-	if err != nil {
-		return nil, err
-	}
-	esym, err := findPESymbol(f, ename)
-	if err != nil {
-		return nil, err
-	}
-	if ssym.SectionNumber != esym.SectionNumber {
-		return nil, fmt.Errorf("%s and %s symbols must be in the same section", sname, ename)
-	}
-	sect := f.Sections[ssym.SectionNumber-1]
-	data, err := sect.Data()
-	if err != nil {
-		return nil, err
-	}
-	return data[ssym.Value:esym.Value], nil
-}
-
-func findPlan9Symbol(f *plan9obj.File, name string) (*plan9obj.Sym, error) {
-	syms, err := f.Symbols()
-	if err != nil {
-		return nil, err
-	}
-	for _, s := range syms {
-		if s.Name != name {
-			continue
-		}
-		return &s, nil
-	}
-	return nil, fmt.Errorf("no %s symbol found", name)
-}
-
-func loadPlan9Table(f *plan9obj.File, sname, ename string) ([]byte, error) {
-	ssym, err := findPlan9Symbol(f, sname)
-	if err != nil {
-		return nil, err
-	}
-	esym, err := findPlan9Symbol(f, ename)
-	if err != nil {
-		return nil, err
-	}
-	sect := f.Section("text")
-	if sect == nil {
-		return nil, err
-	}
-	data, err := sect.Data()
-	if err != nil {
-		return nil, err
-	}
-	textStart := f.LoadAddress + f.HdrSize
-	return data[ssym.Value-textStart : esym.Value-textStart], nil
-}
diff --git a/src/cmd/api/goapi.go b/src/cmd/api/goapi.go
index 932b5520f..7e8f85848 100644
--- a/src/cmd/api/goapi.go
+++ b/src/cmd/api/goapi.go
@@ -378,7 +378,51 @@ func (w *Walker) parseFile(dir, file string) (*ast.File, error) {
 	}
 	if w.context != nil && file == fmt.Sprintf("zruntime_defs_%s_%s.go", w.context.GOOS, w.context.GOARCH) {
 		// Just enough to keep the api checker happy.
-		src := "package runtime; type maptype struct{}; type _type struct{}; type alg struct{}; type mspan struct{}; type m struct{}; type lock struct{}; type slicetype struct{};"
+		src := "package runtime; type (" +
+			" _defer struct{};" +
+			" _func struct{};" +
+			" _panic struct{};" +
+			" _select struct{}; " +
+			" _type struct{};" +
+			" alg struct{};" +
+			" chantype struct{};" +
+			" context struct{};" + // windows
+			" eface struct{};" +
+			" funcval struct{};" +
+			" g struct{};" +
+			" gobuf struct{};" +
+			" hchan struct{};" +
+			" iface struct{};" +
+			" interfacetype struct{};" +
+			" itab struct{};" +
+			" m struct{};" +
+			" maptype struct{};" +
+			" mcache struct{};" +
+			" mspan struct{};" +
+			" mutex struct{};" +
+			" note struct{};" +
+			" slicetype struct{};" +
+			" stkframe struct{};" +
+			" sudog struct{};" +
+			" waitq struct{};" +
+			" wincallbackcontext struct{};" +
+			" keventt struct{};" +
+			" timespec struct{};" +
+			" epollevent struct{};" +
+			"); " +
+			"const (" +
+			" cb_max = 2000;" +
+			" _CacheLineSize = 64;" +
+			" _Gidle = 1;" +
+			" _Grunnable = 2;" +
+			" _Grunning = 3;" +
+			" _Gsyscall = 4;" +
+			" _Gwaiting = 5;" +
+			" _Gdead = 6;" +
+			" _Genqueue = 7;" +
+			" _Gcopystack = 8;" +
+			" _NSIG = 32;" +
+			")"
 		f, err = parser.ParseFile(fset, filename, src, 0)
 		if err != nil {
 			log.Fatalf("incorrect generated file: %s", err)
diff --git a/src/cmd/api/run.go b/src/cmd/api/run.go
index 896b2b4a1..c323deb60 100644
--- a/src/cmd/api/run.go
+++ b/src/cmd/api/run.go
@@ -98,11 +98,9 @@ func prepGoPath() string {
 	if err == nil {
 		username = u.Username
 	} else {
-		// Only need to handle Unix here, as Windows's os/user uses
-		// native syscall and should work fine without cgo.
 		username = os.Getenv("USER")
 		if username == "" {
-			log.Fatalf("Error getting current user: %v", err)
+			username = "nobody"
 		}
 	}
 
diff --git a/src/cmd/cc/cc.h b/src/cmd/cc/cc.h
index c8aac1253..1dae5acd9 100644
--- a/src/cmd/cc/cc.h
+++ b/src/cmd/cc/cc.h
@@ -794,7 +794,7 @@ void	xcom(Node*);
 int32	exreg(Type*);
 int32	align(int32, Type*, int, int32*);
 int32	maxround(int32, int32);
-int	hasdotdotdot(void);
+int	hasdotdotdot(Type*);
 void    linkarchinit(void);
 
 extern	schar	ewidth[];
diff --git a/src/cmd/cc/cc.y b/src/cmd/cc/cc.y
index 11ee444b7..8d7cb1472 100644
--- a/src/cmd/cc/cc.y
+++ b/src/cmd/cc/cc.y
@@ -1043,6 +1043,7 @@ complex:
 	}
 |	LSTRUCT sbody
 	{
+		diag(Z, "struct must have tag");
 		taggen++;
 		sprint(symb, "_%d_", taggen);
 		$$ = dotag(lookup(), TSTRUCT, autobn);
diff --git a/src/cmd/cc/dcl.c b/src/cmd/cc/dcl.c
index a7a942686..292717d68 100644
--- a/src/cmd/cc/dcl.c
+++ b/src/cmd/cc/dcl.c
@@ -697,7 +697,8 @@ argmark(Node *n, int pass)
 {
 	Type *t;
 
-	autoffset = align(0, thisfn->link, Aarg0, nil);
+	if(hasdotdotdot(thisfn->link))
+		autoffset = align(0, thisfn->link, Aarg0, nil);
 	stkoff = 0;
 	for(; n->left != Z; n = n->left) {
 		if(n->op != OFUNC || n->left->op != ONAME)
@@ -1401,6 +1402,10 @@ xdecl(int c, Type *t, Sym *s)
 		}
 	tmerge(t, s);
 	s->type = t;
+	if(c == CTYPEDEF && (typechlv[t->etype] || typefd[t->etype])) {
+		s->type = copytyp(t);
+		s->type->tag = s;
+	}
 	s->class = c;
 	s->block = 0;
 	s->offset = o;
@@ -1481,12 +1486,9 @@ edecl(int c, Type *t, Sym *s)
 {
 	Type *t1;
 
-	if(s == S) {
-		if(!typesu[t->etype])
-			diag(Z, "unnamed structure element must be struct/union");
-		if(c != CXXX)
-			diag(Z, "unnamed structure element cannot have class");
-	} else
+	if(s == S)
+		diag(Z, "unnamed structure elements not supported");
+	else
 		if(c != CXXX)
 			diag(Z, "structure element cannot have class: %s", s->name);
 	t1 = t;
diff --git a/src/cmd/cc/godefs.c b/src/cmd/cc/godefs.c
index 3755a8fc0..d3ab52fde 100644
--- a/src/cmd/cc/godefs.c
+++ b/src/cmd/cc/godefs.c
@@ -154,7 +154,6 @@ static void
 printtypename(Type *t)
 {
 	Sym *s;
-	Type *t1;
 	int w;
 	char *n;
 
@@ -188,60 +187,27 @@ printtypename(Type *t)
 
 	switch(t->etype) {
 	case TINT:
-		Bprint(&outbuf, "int32");
-		break;
 	case TUINT:
-		Bprint(&outbuf, "uint32");
-		break;
 	case TCHAR:
-		Bprint(&outbuf, "int8");
-		break;
 	case TUCHAR:
-		Bprint(&outbuf, "uint8");
-		break;
 	case TSHORT:
-		Bprint(&outbuf, "int16");
-		break;
 	case TUSHORT:
-		Bprint(&outbuf, "uint16");
-		break;
 	case TLONG:
-		// The 32/64-bit ambiguous types (int,uint,uintptr)
-		// are assigned a TLONG/TULONG to distinguish them
-		// from always 32-bit types which get a TINT/TUINT.
-		// (See int_x/uint_x in pkg/runtime/runtime.h.)
-		// For LONG and VLONG types, we generate the
-		// unqualified Go type when appropriate.
-		// This makes it easier to write Go code that
-		// modifies objects with autogenerated-from-C types.
-		if(ewidth[TIND] == 4)
-			Bprint(&outbuf, "int");
-		else
-			Bprint(&outbuf, "int32");
-		break;
 	case TULONG:
-		if(ewidth[TIND] == 4)
-			Bprint(&outbuf, "uint");
-		else
-			Bprint(&outbuf, "uint32");
-		break;
 	case TVLONG:
-		if(ewidth[TIND] == 8)
-			Bprint(&outbuf, "int");
-		else
-			Bprint(&outbuf, "int64");
-		break;
 	case TUVLONG:
-		if(ewidth[TIND] == 8)
-			Bprint(&outbuf, "uint");
-		else
-			Bprint(&outbuf, "uint64");
-		break;
 	case TFLOAT:
-		Bprint(&outbuf, "float32");
-		break;
 	case TDOUBLE:
-		Bprint(&outbuf, "float64");
+		// All names used in the runtime code should be typedefs.
+		if(t->tag != nil) {
+			if(strcmp(t->tag->name, "intgo") == 0)
+				Bprint(&outbuf, "int");
+			else if(strcmp(t->tag->name, "uintgo") == 0)
+				Bprint(&outbuf, "uint");
+			else
+				Bprint(&outbuf, "%s", t->tag->name);
+		} else	
+			Bprint(&outbuf, "C.%T", t);
 		break;
 	case TUNION:
 	case TSTRUCT:
@@ -251,27 +217,18 @@ printtypename(Type *t)
 			n = s->name;
 		else if(t->tag)
 			n = t->tag->name;
-		if(strcmp(n, "String") == 0){
+		if(strcmp(n, "String") == 0)
 			Bprint(&outbuf, "string");
-		} else if(strcmp(n, "Slice") == 0){
+		else if(strcmp(n, "Slice") == 0)
 			Bprint(&outbuf, "[]byte");
-		} else
+		else if(strcmp(n, "Eface") == 0)
+			Bprint(&outbuf, "interface{}");
+		else
 			Bprint(&outbuf, "%U", n);
 		break;
 	case TFUNC:
-		Bprint(&outbuf, "func(");
-		for(t1 = t->down; t1 != T; t1 = t1->down) {
-			if(t1->etype == TVOID)
-				break;
-			if(t1 != t->down)
-				Bprint(&outbuf, ", ");
-			printtypename(t1);
-		}
-		Bprint(&outbuf, ")");
-		if(t->link && t->link->etype != TVOID) {
-			Bprint(&outbuf, " ");
-			printtypename(t->link);
-		}
+		// There's no equivalent to a C function in the Go world.
+		Bprint(&outbuf, "unsafe.Pointer");
 		break;
 	case TDOT:
 		Bprint(&outbuf, "...interface{}");
@@ -360,9 +317,9 @@ godefvar(Sym *s)
 	switch(t->etype) {
 	case TENUM:
 		if(!typefd[t->etype])
-			Bprint(&outbuf, "const %U = %lld\n", s->name, s->vconst);
+			Bprint(&outbuf, "const %s = %lld\n", s->name, s->vconst);
 		else
-			Bprint(&outbuf, "const %U = %f\n;", s->name, s->fconst);
+			Bprint(&outbuf, "const %s = %f\n;", s->name, s->fconst);
 		break;
 
 	case TFUNC:
diff --git a/src/cmd/cc/pgen.c b/src/cmd/cc/pgen.c
index c2cf0e101..4b4684a52 100644
--- a/src/cmd/cc/pgen.c
+++ b/src/cmd/cc/pgen.c
@@ -56,24 +56,24 @@ makefuncdatasym(char *namefmt, int64 funcdatakind)
 }
 
 int
-hasdotdotdot(void)
+hasdotdotdot(Type *t)
 {
-	Type *t;
-
-	for(t=thisfn->down; t!=T; t=t->down)
+	for(t=t->down; t!=T; t=t->down)
 		if(t->etype == TDOT)
 			return 1;
 	return 0;
 }
 
 vlong
-argsize(void)
+argsize(int doret)
 {
 	Type *t;
 	int32 s;
 
 //print("t=%T\n", thisfn);
-	s = align(0, thisfn->link, Aarg0, nil);
+	s = 0;
+	if(hasdotdotdot(thisfn))
+		s = align(s, thisfn->link, Aarg0, nil);
 	for(t=thisfn->down; t!=T; t=t->down) {
 		switch(t->etype) {
 		case TVOID:
@@ -93,6 +93,14 @@ argsize(void)
 		s = (s+7) & ~7;
 	else
 		s = (s+3) & ~3;
+	if(doret && thisfn->link->etype != TVOID) {
+		s = align(s, thisfn->link, Aarg1, nil);
+		s = align(s, thisfn->link, Aarg2, nil);
+		if(thechar == '6')
+			s = (s+7) & ~7;
+		else
+			s = (s+3) & ~3;
+	}
 	return s;
 }
 
@@ -123,13 +131,14 @@ codgen(Node *n, Node *nn)
 	nearln = nn->lineno;
 
 	p = gtext(n1->sym, stkoff);
+	p->from.sym->cfunc = 1;
 	sp = p;
 
 	/*
 	 * generate funcdata symbol for this function.
 	 * data is filled in at the end of codgen().
 	 */
-	isvarargs = hasdotdotdot();
+	isvarargs = hasdotdotdot(thisfn);
 	gcargs = nil;
 	if(!isvarargs)
 		gcargs = makefuncdatasym("gcargs·%d", FUNCDATA_ArgsPointerMaps);
@@ -212,7 +221,7 @@ supgen(Node *n)
 void
 gen(Node *n)
 {
-	Node *l, nod;
+	Node *l, nod, nod1;
 	Prog *sp, *spc, *spb;
 	Case *cn;
 	long sbc, scc;
@@ -273,14 +282,26 @@ loop:
 			gbranch(ORETURN);
 			break;
 		}
+		if(typecmplx[n->type->etype] && !hasdotdotdot(thisfn)) {
+			regret(&nod, n, thisfn, 2);
+			sugen(l, &nod, n->type->width);
+			noretval(3);
+			gbranch(ORETURN);
+			break;
+		}
 		if(typecmplx[n->type->etype]) {
 			sugen(l, nodret, n->type->width);
 			noretval(3);
 			gbranch(ORETURN);
 			break;
 		}
-		regret(&nod, n);
+		regret(&nod1, n, thisfn, 2);
+		nod = nod1;
+		if(nod.op != OREGISTER)
+			regalloc(&nod, n, Z);
 		cgen(l, &nod);
+		if(nod1.op != OREGISTER)
+			gmove(&nod, &nod1);
 		regfree(&nod);
 		if(typefd[n->type->etype])
 			noretval(1);
@@ -729,9 +750,11 @@ dumpgcargs(Type *fn, Sym *sym)
 	symoffset = 0;
 	gextern(sym, nodconst(1), symoffset, 4);
 	symoffset += 4;
-	argbytes = (argsize() + ewidth[TIND] - 1);
+	argbytes = (argsize(1) + ewidth[TIND] - 1);
 	bv = bvalloc((argbytes  / ewidth[TIND]) * BitsPerPointer);
-	argoffset = align(0, fn->link, Aarg0, nil);
+	argoffset = 0;
+	if(hasdotdotdot(thisfn))
+		argoffset = align(0, fn->link, Aarg0, nil);
 	if(argoffset > 0) {
 		// The C calling convention returns structs by copying them to a
 		// location pointed to by a hidden first argument.  This first
diff --git a/src/cmd/cgo/gcc.go b/src/cmd/cgo/gcc.go
index 841c84833..d77d56c22 100644
--- a/src/cmd/cgo/gcc.go
+++ b/src/cmd/cgo/gcc.go
@@ -229,7 +229,8 @@ func (p *Package) guessKinds(f *File) []*Name {
 	// Determine kinds for names we already know about,
 	// like #defines or 'struct foo', before bothering with gcc.
 	var names, needType []*Name
-	for _, n := range f.Name {
+	for _, key := range nameKeys(f.Name) {
+		n := f.Name[key]
 		// If we've already found this name as a #define
 		// and we can translate it as a constant value, do so.
 		if n.Define != "" {
@@ -331,6 +332,7 @@ func (p *Package) guessKinds(f *File) []*Name {
 	const (
 		notType = 1 << iota
 		notConst
+		notDeclared
 	)
 	for _, line := range strings.Split(stderr, "\n") {
 		if !strings.Contains(line, ": error:") {
@@ -365,7 +367,7 @@ func (p *Package) guessKinds(f *File) []*Name {
 			completed = true
 
 		case "not-declared":
-			error_(token.NoPos, "%s", strings.TrimSpace(line[c2+1:]))
+			sniff[i] |= notDeclared
 		case "not-type":
 			sniff[i] |= notType
 		case "not-const":
@@ -374,12 +376,12 @@ func (p *Package) guessKinds(f *File) []*Name {
 	}
 
 	if !completed {
-		fatalf("%s did not produce error at completed:1\non input:\n%s", p.gccBaseCmd()[0], b.Bytes())
+		fatalf("%s did not produce error at completed:1\non input:\n%s\nfull error output:\n%s", p.gccBaseCmd()[0], b.Bytes(), stderr)
 	}
 
 	for i, n := range names {
 		switch sniff[i] {
-		case 0:
+		default:
 			error_(token.NoPos, "could not determine kind of name for C.%s", fixGo(n.Go))
 		case notType:
 			n.Kind = "const"
@@ -390,6 +392,14 @@ func (p *Package) guessKinds(f *File) []*Name {
 		}
 	}
 	if nerrors > 0 {
+		// Check if compiling the preamble by itself causes any errors,
+		// because the messages we've printed out so far aren't helpful
+		// to users debugging preamble mistakes.  See issue 8442.
+		preambleErrors := p.gccErrors([]byte(f.Preamble))
+		if len(preambleErrors) > 0 {
+			error_(token.NoPos, "\n%s errors for preamble:\n%s", p.gccBaseCmd()[0], preambleErrors)
+		}
+
 		fatalf("unresolved names")
 	}
 
@@ -649,7 +659,13 @@ func (p *Package) rewriteRef(f *File) {
 					f.Name[fpName] = name
 				}
 				r.Name = name
-				expr = ast.NewIdent(name.Mangle)
+				// Rewrite into call to _Cgo_ptr to prevent assignments.  The _Cgo_ptr
+				// function is defined in out.go and simply returns its argument. See
+				// issue 7757.
+				expr = &ast.CallExpr{
+					Fun:  &ast.Ident{NamePos: (*r.Expr).Pos(), Name: "_Cgo_ptr"},
+					Args: []ast.Expr{ast.NewIdent(name.Mangle)},
+				}
 			} else if r.Name.Kind == "type" {
 				// Okay - might be new(T)
 				expr = r.Name.Type.Go
@@ -1068,12 +1084,6 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 		return t
 	}
 
-	// clang won't generate DW_AT_byte_size for pointer types,
-	// so we have to fix it here.
-	if dt, ok := base(dtype).(*dwarf.PtrType); ok && dt.ByteSize == -1 {
-		dt.ByteSize = c.ptrSize
-	}
-
 	t := new(Type)
 	t.Size = dtype.Size() // note: wrong for array of pointers, corrected below
 	t.Align = -1
@@ -1097,12 +1107,20 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 			t.Go = c.Opaque(t.Size)
 			break
 		}
+		count := dt.Count
+		if count == -1 {
+			// Indicates flexible array member, which Go doesn't support.
+			// Translate to zero-length array instead.
+			count = 0
+		}
 		sub := c.Type(dt.Type, pos)
 		t.Align = sub.Align
 		t.Go = &ast.ArrayType{
-			Len: c.intExpr(dt.Count),
+			Len: c.intExpr(count),
 			Elt: sub.Go,
 		}
+		// Recalculate t.Size now that we know sub.Size.
+		t.Size = count * sub.Size
 		t.C.Set("__typeof__(%s[%d])", sub.C, dt.Count)
 
 	case *dwarf.BoolType:
@@ -1203,6 +1221,11 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 		}
 
 	case *dwarf.PtrType:
+		// Clang doesn't emit DW_AT_byte_size for pointer types.
+		if t.Size != c.ptrSize && t.Size != -1 {
+			fatalf("%s: unexpected: %d-byte pointer type - %s", lineno(pos), t.Size, dtype)
+		}
+		t.Size = c.ptrSize
 		t.Align = c.ptrSize
 
 		if _, ok := base(dt.Type).(*dwarf.VoidType); ok {
@@ -1374,34 +1397,24 @@ func (c *typeConv) Type(dtype dwarf.Type, pos token.Pos) *Type {
 		}
 	}
 
-	if t.Size <= 0 {
-		// Clang does not record the size of a pointer in its DWARF entry,
-		// so if dtype is an array, the call to dtype.Size at the top of the function
-		// computed the size as the array length * 0 = 0.
-		// The type switch called Type (this function) recursively on the pointer
-		// entry, and the code near the top of the function updated the size to
-		// be correct, so calling dtype.Size again will produce the correct value.
-		t.Size = dtype.Size()
-		if t.Size < 0 {
-			// Unsized types are [0]byte, unless they're typedefs of other types
-			// or structs with tags.
-			// if so, use the name we've already defined.
-			t.Size = 0
-			switch dt := dtype.(type) {
-			case *dwarf.TypedefType:
-				// ok
-			case *dwarf.StructType:
-				if dt.StructName != "" {
-					break
-				}
-				t.Go = c.Opaque(0)
-			default:
-				t.Go = c.Opaque(0)
-			}
-			if t.C.Empty() {
-				t.C.Set("void")
+	if t.Size < 0 {
+		// Unsized types are [0]byte, unless they're typedefs of other types
+		// or structs with tags.
+		// if so, use the name we've already defined.
+		t.Size = 0
+		switch dt := dtype.(type) {
+		case *dwarf.TypedefType:
+			// ok
+		case *dwarf.StructType:
+			if dt.StructName != "" {
+				break
 			}
-			return t
+			t.Go = c.Opaque(0)
+		default:
+			t.Go = c.Opaque(0)
+		}
+		if t.C.Empty() {
+			t.C.Set("void")
 		}
 	}
 
@@ -1533,6 +1546,9 @@ func (c *typeConv) pad(fld []*ast.Field, size int64) []*ast.Field {
 
 // Struct conversion: return Go and (6g) C syntax for type.
 func (c *typeConv) Struct(dt *dwarf.StructType, pos token.Pos) (expr *ast.StructType, csyntax string, align int64) {
+	// Minimum alignment for a struct is 1 byte.
+	align = 1
+
 	var buf bytes.Buffer
 	buf.WriteString("struct {")
 	fld := make([]*ast.Field, 0, 2*len(dt.Field)+1) // enough for padding around every field
diff --git a/src/cmd/cgo/out.go b/src/cmd/cgo/out.go
index 1ef78b757..6586531ad 100644
--- a/src/cmd/cgo/out.go
+++ b/src/cmd/cgo/out.go
@@ -58,16 +58,14 @@ func (p *Package) writeDefs() {
 	fmt.Fprintf(fgo2, "// Created by cgo - DO NOT EDIT\n\n")
 	fmt.Fprintf(fgo2, "package %s\n\n", p.PackageName)
 	fmt.Fprintf(fgo2, "import \"unsafe\"\n\n")
-	if *importSyscall {
-		fmt.Fprintf(fgo2, "import \"syscall\"\n\n")
-	}
 	if !*gccgo && *importRuntimeCgo {
 		fmt.Fprintf(fgo2, "import _ \"runtime/cgo\"\n\n")
 	}
-	fmt.Fprintf(fgo2, "type _ unsafe.Pointer\n\n")
 	if *importSyscall {
-		fmt.Fprintf(fgo2, "func _Cerrno(dst *error, x int32) { *dst = syscall.Errno(x) }\n")
+		fmt.Fprintf(fgo2, "import \"syscall\"\n\n")
+		fmt.Fprintf(fgo2, "var _ syscall.Errno\n")
 	}
+	fmt.Fprintf(fgo2, "func _Cgo_ptr(ptr unsafe.Pointer) unsafe.Pointer { return ptr }\n\n")
 
 	typedefNames := make([]string, 0, len(typedef))
 	for name := range typedef {
@@ -87,9 +85,10 @@ func (p *Package) writeDefs() {
 	}
 
 	if *gccgo {
-		fmt.Fprintf(fc, p.cPrologGccgo())
+		fmt.Fprint(fc, p.cPrologGccgo())
 	} else {
-		fmt.Fprintf(fc, cProlog)
+		fmt.Fprint(fc, cProlog)
+		fmt.Fprint(fgo2, goProlog)
 	}
 
 	gccgoSymbolPrefix := p.gccgoSymbolPrefix()
@@ -296,10 +295,6 @@ func (p *Package) structType(n *Name) (string, int64) {
 		fmt.Fprintf(&buf, "\t\tchar __pad%d[%d];\n", off, pad)
 		off += pad
 	}
-	if n.AddError {
-		fmt.Fprint(&buf, "\t\tint e[2*sizeof(void *)/sizeof(int)]; /* error */\n")
-		off += 2 * p.PtrSize
-	}
 	if off == 0 {
 		fmt.Fprintf(&buf, "\t\tchar unused;\n") // avoid empty struct
 	}
@@ -334,19 +329,18 @@ func (p *Package) writeDefsFunc(fc, fgo2 *os.File, n *Name) {
 	}
 
 	// Builtins defined in the C prolog.
-	inProlog := name == "CString" || name == "GoString" || name == "GoStringN" || name == "GoBytes" || name == "_CMalloc"
+	inProlog := builtinDefs[name] != ""
+	cname := fmt.Sprintf("_cgo%s%s", cPrefix, n.Mangle)
+	paramnames := []string(nil)
+	for i, param := range d.Type.Params.List {
+		paramName := fmt.Sprintf("p%d", i)
+		param.Names = []*ast.Ident{ast.NewIdent(paramName)}
+		paramnames = append(paramnames, paramName)
+	}
 
 	if *gccgo {
 		// Gccgo style hooks.
 		fmt.Fprint(fgo2, "\n")
-		cname := fmt.Sprintf("_cgo%s%s", cPrefix, n.Mangle)
-		paramnames := []string(nil)
-		for i, param := range d.Type.Params.List {
-			paramName := fmt.Sprintf("p%d", i)
-			param.Names = []*ast.Ident{ast.NewIdent(paramName)}
-			paramnames = append(paramnames, paramName)
-		}
-
 		conf.Fprint(fgo2, fset, d)
 		fmt.Fprint(fgo2, " {\n")
 		if !inProlog {
@@ -383,7 +377,7 @@ func (p *Package) writeDefsFunc(fc, fgo2 *os.File, n *Name) {
 		fmt.Fprint(fgo2, "}\n")
 
 		// declare the C function.
-		fmt.Fprintf(fgo2, "//extern _cgo%s%s\n", cPrefix, n.Mangle)
+		fmt.Fprintf(fgo2, "//extern %s\n", cname)
 		d.Name = ast.NewIdent(cname)
 		if n.AddError {
 			l := d.Type.Results.List
@@ -394,61 +388,49 @@ func (p *Package) writeDefsFunc(fc, fgo2 *os.File, n *Name) {
 
 		return
 	}
-	conf.Fprint(fgo2, fset, d)
-	fmt.Fprint(fgo2, "\n")
 
 	if inProlog {
+		fmt.Fprint(fgo2, builtinDefs[name])
 		return
 	}
 
-	var argSize int64
-	_, argSize = p.structType(n)
-
 	// C wrapper calls into gcc, passing a pointer to the argument frame.
-	fmt.Fprintf(fc, "#pragma cgo_import_static _cgo%s%s\n", cPrefix, n.Mangle)
-	fmt.Fprintf(fc, "void _cgo%s%s(void*);\n", cPrefix, n.Mangle)
-	fmt.Fprintf(fc, "\n")
-	fmt.Fprintf(fc, "void\n")
-	if argSize == 0 {
-		argSize++
+	fmt.Fprintf(fc, "#pragma cgo_import_static %s\n", cname)
+	fmt.Fprintf(fc, "void %s(void*);\n", cname)
+	fmt.Fprintf(fc, "void *·%s = %s;\n", cname, cname)
+
+	nret := 0
+	if !void {
+		d.Type.Results.List[0].Names = []*ast.Ident{ast.NewIdent("r1")}
+		nret = 1
 	}
-	// TODO(rsc): The struct here should declare pointers only where
-	// there are pointers in the actual argument frame.
-	// This is a workaround for golang.org/issue/6397.
-	fmt.Fprintf(fc, "·%s(struct{", n.Mangle)
-	if n := argSize / p.PtrSize; n > 0 {
-		fmt.Fprintf(fc, "void *y[%d];", n)
+	if n.AddError {
+		d.Type.Results.List[nret].Names = []*ast.Ident{ast.NewIdent("r2")}
 	}
-	if n := argSize % p.PtrSize; n > 0 {
-		fmt.Fprintf(fc, "uint8 x[%d];", n)
+
+	fmt.Fprint(fgo2, "\n")
+	fmt.Fprintf(fgo2, "var %s unsafe.Pointer\n", cname)
+	conf.Fprint(fgo2, fset, d)
+	fmt.Fprint(fgo2, " {\n")
+
+	// NOTE: Using uintptr to hide from escape analysis.
+	arg := "0"
+	if len(paramnames) > 0 {
+		arg = "uintptr(unsafe.Pointer(&p0))"
+	} else if !void {
+		arg = "uintptr(unsafe.Pointer(&r1))"
 	}
-	fmt.Fprintf(fc, "}p)\n")
-	fmt.Fprintf(fc, "{\n")
-	fmt.Fprintf(fc, "\truntime·cgocall(_cgo%s%s, &p);\n", cPrefix, n.Mangle)
+
+	prefix := ""
 	if n.AddError {
-		// gcc leaves errno in first word of interface at end of p.
-		// check whether it is zero; if so, turn interface into nil.
-		// if not, turn interface into errno.
-		// Go init function initializes ·_Cerrno with an os.Errno
-		// for us to copy.
-		fmt.Fprintln(fc, `	{
-			int32 e;
-			void **v;
-			v = (void**)(&p+1) - 2;	/* v = final two void* of p */
-			e = *(int32*)v;
-			v[0] = (void*)0xdeadbeef;
-			v[1] = (void*)0xdeadbeef;
-			if(e == 0) {
-				/* nil interface */
-				v[0] = 0;
-				v[1] = 0;
-			} else {
-				·_Cerrno(v, e);	/* fill in v as error for errno e */
-			}
-		}`)
+		prefix = "errno := "
 	}
-	fmt.Fprintf(fc, "}\n")
-	fmt.Fprintf(fc, "\n")
+	fmt.Fprintf(fgo2, "\t%s_cgo_runtime_cgocall_errno(%s, %s)\n", prefix, cname, arg)
+	if n.AddError {
+		fmt.Fprintf(fgo2, "\tif errno != 0 { r2 = syscall.Errno(errno) }\n")
+	}
+	fmt.Fprintf(fgo2, "\treturn\n")
+	fmt.Fprintf(fgo2, "}\n")
 }
 
 // writeOutput creates stubs for a specific source file to be compiled by 6g
@@ -521,7 +503,11 @@ func (p *Package) writeOutputFunc(fgcc *os.File, n *Name) {
 
 	// Gcc wrapper unpacks the C argument struct
 	// and calls the actual C function.
-	fmt.Fprintf(fgcc, "void\n")
+	if n.AddError {
+		fmt.Fprintf(fgcc, "int\n")
+	} else {
+		fmt.Fprintf(fgcc, "void\n")
+	}
 	fmt.Fprintf(fgcc, "_cgo%s%s(void *v)\n", cPrefix, n.Mangle)
 	fmt.Fprintf(fgcc, "{\n")
 	if n.AddError {
@@ -557,7 +543,7 @@ func (p *Package) writeOutputFunc(fgcc *os.File, n *Name) {
 	}
 	fmt.Fprintf(fgcc, ");\n")
 	if n.AddError {
-		fmt.Fprintf(fgcc, "\t*(int*)(a->e) = errno;\n")
+		fmt.Fprintf(fgcc, "\treturn errno;\n")
 	}
 	fmt.Fprintf(fgcc, "}\n")
 	fmt.Fprintf(fgcc, "\n")
@@ -1166,46 +1152,74 @@ const cProlog = `
 #include "runtime.h"
 #include "cgocall.h"
 
+static void *cgocall_errno = runtime·cgocall_errno;
+void *·_cgo_runtime_cgocall_errno = &cgocall_errno;
+
+static void *runtime_gostring = runtime·gostring;
+void *·_cgo_runtime_gostring = &runtime_gostring;
+
+static void *runtime_gostringn = runtime·gostringn;
+void *·_cgo_runtime_gostringn = &runtime_gostringn;
+
+static void *runtime_gobytes = runtime·gobytes;
+void *·_cgo_runtime_gobytes = &runtime_gobytes;
+
+static void *runtime_cmalloc = runtime·cmalloc;
+void *·_cgo_runtime_cmalloc = &runtime_cmalloc;
+
 void ·_Cerrno(void*, int32);
+`
 
-void
-·_Cfunc_GoString(int8 *p, String s)
-{
-	s = runtime·gostring((byte*)p);
-	FLUSH(&s);
+const goProlog = `
+var _cgo_runtime_cgocall_errno func(unsafe.Pointer, uintptr) int32
+var _cgo_runtime_cmalloc func(uintptr) unsafe.Pointer
+`
+
+const goStringDef = `
+var _cgo_runtime_gostring func(*_Ctype_char) string
+func _Cfunc_GoString(p *_Ctype_char) string {
+	return _cgo_runtime_gostring(p)
 }
+`
 
-void
-·_Cfunc_GoStringN(int8 *p, int32 l, String s)
-{
-	s = runtime·gostringn((byte*)p, l);
-	FLUSH(&s);
+const goStringNDef = `
+var _cgo_runtime_gostringn func(*_Ctype_char, int) string
+func _Cfunc_GoStringN(p *_Ctype_char, l _Ctype_int) string {
+	return _cgo_runtime_gostringn(p, int(l))
 }
+`
 
-void
-·_Cfunc_GoBytes(int8 *p, int32 l, Slice s)
-{
-	s = runtime·gobytes((byte*)p, l);
-	FLUSH(&s);
+const goBytesDef = `
+var _cgo_runtime_gobytes func(unsafe.Pointer, int) []byte
+func _Cfunc_GoBytes(p unsafe.Pointer, l _Ctype_int) []byte {
+	return _cgo_runtime_gobytes(p, int(l))
 }
+`
 
-void
-·_Cfunc_CString(String s, int8 *p)
-{
-	p = runtime·cmalloc(s.len+1);
-	runtime·memmove((byte*)p, s.str, s.len);
-	p[s.len] = 0;
-	FLUSH(&p);
+const cStringDef = `
+func _Cfunc_CString(s string) *_Ctype_char {
+	p := _cgo_runtime_cmalloc(uintptr(len(s)+1))
+	pp := (*[1<<30]byte)(p)
+	copy(pp[:], s)
+	pp[len(s)] = 0
+	return (*_Ctype_char)(p)
 }
+`
 
-void
-·_Cfunc__CMalloc(uintptr n, int8 *p)
-{
-	p = runtime·cmalloc(n);
-	FLUSH(&p);
+const cMallocDef = `
+func _Cfunc__CMalloc(n _Ctype_size_t) unsafe.Pointer {
+	return _cgo_runtime_cmalloc(uintptr(n))
 }
 `
 
+var builtinDefs = map[string]string{
+	"GoString":  goStringDef,
+	"GoStringN": goStringNDef,
+	"GoBytes":   goBytesDef,
+	"CString":   cStringDef,
+	"_CMalloc":  cMallocDef,
+}
+
 func (p *Package) cPrologGccgo() string {
 	return strings.Replace(cPrologGccgo, "PREFIX", cPrefix, -1)
 }
diff --git a/src/cmd/dist/a.h b/src/cmd/dist/a.h
index 6222e5060..288063b94 100644
--- a/src/cmd/dist/a.h
+++ b/src/cmd/dist/a.h
@@ -108,9 +108,6 @@ void	mkzexperiment(char*, char*);
 // buildgo.c
 void	mkzdefaultcc(char*, char*);
 
-// goc2c.c
-void	goc2c(char*, char*);
-
 // main.c
 extern int vflag;
 extern int sflag;
@@ -129,6 +126,7 @@ bool	isfile(char *p);
 char*	lastelem(char*);
 Time	mtime(char*);
 void	readfile(Buf*, char*);
+void	copyfile(char*, char*, int);
 void	run(Buf *b, char *dir, int mode, char *cmd, ...);
 void	runv(Buf *b, char *dir, int mode, Vec *argv);
 void	bgrunv(char *dir, int mode, Vec *argv);
diff --git a/src/cmd/dist/buf.c b/src/cmd/dist/buf.c
index 45fb1954d..2ddc6be75 100644
--- a/src/cmd/dist/buf.c
+++ b/src/cmd/dist/buf.c
@@ -202,7 +202,7 @@ vadd(Vec *v, char *p)
 }
 
 // vaddn adds a string consisting of the n bytes at p to the vector.
-void
+static void
 vaddn(Vec *v, char *p, int n)
 {
 	char *q;
diff --git a/src/cmd/dist/build.c b/src/cmd/dist/build.c
index 1feeccf41..6fab14a11 100644
--- a/src/cmd/dist/build.c
+++ b/src/cmd/dist/build.c
@@ -35,7 +35,6 @@ bool	rebuildall;
 bool defaultclang;
 
 static bool shouldbuild(char*, char*);
-static void copy(char*, char*, int);
 static void dopack(char*, char*, char**, int);
 static char *findgoversion(void);
 
@@ -628,7 +627,6 @@ char *depsuffix[] = {
 	".h",
 	".s",
 	".go",
-	".goc",
 };
 
 // gentab records how to generate some trivial files.
@@ -661,7 +659,7 @@ install(char *dir)
 {
 	char *name, *p, *elem, *prefix, *exe;
 	bool islib, ispkg, isgo, stale, ispackcmd;
-	Buf b, b1, path;
+	Buf b, b1, path, final_path, final_name;
 	Vec compile, files, link, go, missing, clean, lib, extra;
 	Time ttarg, t;
 	int i, j, k, n, doclean, targ;
@@ -676,6 +674,8 @@ install(char *dir)
 	binit(&b);
 	binit(&b1);
 	binit(&path);
+	binit(&final_path);
+	binit(&final_name);
 	vinit(&compile);
 	vinit(&files);
 	vinit(&link);
@@ -688,11 +688,12 @@ install(char *dir)
 
 	// path = full path to dir.
 	bpathf(&path, "%s/src/%s", goroot, dir);
+	bpathf(&final_path, "%s/src/%s", goroot_final, dir);
 	name = lastelem(dir);
 
 	// For misc/prof, copy into the tool directory and we're done.
 	if(hasprefix(dir, "misc/")) {
-		copy(bpathf(&b, "%s/%s", tooldir, name),
+		copyfile(bpathf(&b, "%s/%s", tooldir, name),
 			bpathf(&b1, "%s/misc/%s", goroot, name), 1);
 		goto out;
 	}
@@ -904,17 +905,19 @@ install(char *dir)
 
 	// For package runtime, copy some files into the work space.
 	if(streq(dir, "pkg/runtime")) {
-		copy(bpathf(&b, "%s/arch_GOARCH.h", workdir),
+		copyfile(bpathf(&b, "%s/arch_GOARCH.h", workdir),
 			bpathf(&b1, "%s/arch_%s.h", bstr(&path), goarch), 0);
-		copy(bpathf(&b, "%s/defs_GOOS_GOARCH.h", workdir),
+		copyfile(bpathf(&b, "%s/defs_GOOS_GOARCH.h", workdir),
 			bpathf(&b1, "%s/defs_%s_%s.h", bstr(&path), goos, goarch), 0);
 		p = bpathf(&b1, "%s/signal_%s_%s.h", bstr(&path), goos, goarch);
 		if(isfile(p))
-			copy(bpathf(&b, "%s/signal_GOOS_GOARCH.h", workdir), p, 0);
-		copy(bpathf(&b, "%s/os_GOOS.h", workdir),
+			copyfile(bpathf(&b, "%s/signal_GOOS_GOARCH.h", workdir), p, 0);
+		copyfile(bpathf(&b, "%s/os_GOOS.h", workdir),
 			bpathf(&b1, "%s/os_%s.h", bstr(&path), goos), 0);
-		copy(bpathf(&b, "%s/signals_GOOS.h", workdir),
+		copyfile(bpathf(&b, "%s/signals_GOOS.h", workdir),
 			bpathf(&b1, "%s/signals_%s.h", bstr(&path), goos), 0);
+		copyfile(bpathf(&b, "%s/pkg/%s_%s/textflag.h", goroot, goos, goarch),
+			bpathf(&b1, "%s/src/cmd/ld/textflag.h", goroot), 0);
 	}
 
 	// Generate any missing files; regenerate existing ones.
@@ -948,26 +951,10 @@ install(char *dir)
 	// The last batch was required for the generators.
 	// This one is generated.
 	if(streq(dir, "pkg/runtime")) {
-		copy(bpathf(&b, "%s/zasm_GOOS_GOARCH.h", workdir),
+		copyfile(bpathf(&b, "%s/zasm_GOOS_GOARCH.h", workdir),
 			bpathf(&b1, "%s/zasm_%s_%s.h", bstr(&path), goos, goarch), 0);
 	}
 
-	// Generate .c files from .goc files.
-	if(streq(dir, "pkg/runtime")) {
-		for(i=0; i<files.len; i++) {
-			p = files.p[i];
-			if(!hassuffix(p, ".goc"))
-				continue;
-			// b = path/zp but with _goos_goarch.c instead of .goc
-			bprintf(&b, "%s%sz%s", bstr(&path), slash, lastelem(p));
-			b.len -= 4;
-			bwritef(&b, "_%s_%s.c", goos, goarch);
-			goc2c(p, bstr(&b));
-			vadd(&files, bstr(&b));
-		}
-		vuniq(&files);
-	}
-
 	if((!streq(goos, gohostos) || !streq(goarch, gohostarch)) && isgo) {
 		// We've generated the right files; the go command can do the build.
 		if(vflag > 1)
@@ -1138,9 +1125,9 @@ nobuild:
 	// In package runtime, we install runtime.h and cgocall.h too,
 	// for use by cgo compilation.
 	if(streq(dir, "pkg/runtime")) {
-		copy(bpathf(&b, "%s/pkg/%s_%s/cgocall.h", goroot, goos, goarch),
+		copyfile(bpathf(&b, "%s/pkg/%s_%s/cgocall.h", goroot, goos, goarch),
 			bpathf(&b1, "%s/src/pkg/runtime/cgocall.h", goroot), 0);
-		copy(bpathf(&b, "%s/pkg/%s_%s/runtime.h", goroot, goos, goarch),
+		copyfile(bpathf(&b, "%s/pkg/%s_%s/runtime.h", goroot, goos, goarch),
 			bpathf(&b1, "%s/src/pkg/runtime/runtime.h", goroot), 0);
 	}
 
@@ -1277,8 +1264,8 @@ out:
 }
 
 // copy copies the file src to dst, via memory (so only good for small files).
-static void
-copy(char *dst, char *src, int exec)
+void
+copyfile(char *dst, char *src, int exec)
 {
 	Buf b;
 
diff --git a/src/cmd/dist/buildruntime.c b/src/cmd/dist/buildruntime.c
index 9b40a5968..7af38456d 100644
--- a/src/cmd/dist/buildruntime.c
+++ b/src/cmd/dist/buildruntime.c
@@ -112,7 +112,7 @@ mkzgoos(char *dir, char *file)
 
 	bwritestr(&out, "// auto generated by go tool dist\n\n");
 
-	if (streq(goos, "linux")) {
+	if(streq(goos, "linux")) {
 		bwritestr(&out, "// +build !android\n\n");
 	}
 	
@@ -169,11 +169,12 @@ mkzasm(char *dir, char *file)
 {
 	int i, n;
 	char *aggr, *p;
-	Buf in, b, out, exp;
+	Buf in, b, b1, out, exp;
 	Vec argv, lines, fields;
 
 	binit(&in);
 	binit(&b);
+	binit(&b1);
 	binit(&out);
 	binit(&exp);
 	vinit(&argv);
@@ -181,6 +182,10 @@ mkzasm(char *dir, char *file)
 	vinit(&fields);
 	
 	bwritestr(&out, "// auto generated by go tool dist\n\n");
+	if(streq(goos, "linux")) {
+		bwritestr(&out, "// +build !android\n\n");
+	}
+	
 	for(i=0; i<nelem(zasmhdr); i++) {
 		if(hasprefix(goarch, zasmhdr[i].goarch) && hasprefix(goos, zasmhdr[i].goos)) {
 			bwritestr(&out, zasmhdr[i].hdr);
@@ -190,6 +195,9 @@ mkzasm(char *dir, char *file)
 	fatal("unknown $GOOS/$GOARCH in mkzasm");
 ok:
 
+	copyfile(bpathf(&b, "%s/pkg/%s_%s/textflag.h", goroot, goos, goarch),
+		bpathf(&b1, "%s/src/cmd/ld/textflag.h", goroot), 0);
+
 	// Run 6c -D GOOS_goos -D GOARCH_goarch -I workdir -a -n -o workdir/proc.acid proc.c
 	// to get acid [sic] output. Run once without the -a -o workdir/proc.acid in order to
 	// report compilation failures (the -o redirects all messages, unfortunately).
@@ -201,6 +209,8 @@ ok:
 	vadd(&argv, bprintf(&b, "GOARCH_%s", goarch));
 	vadd(&argv, "-I");
 	vadd(&argv, bprintf(&b, "%s", workdir));
+	vadd(&argv, "-I");
+	vadd(&argv, bprintf(&b, "%s/pkg/%s_%s", goroot, goos, goarch));
 	vadd(&argv, "-n");
 	vadd(&argv, "-a");
 	vadd(&argv, "-o");
@@ -241,6 +251,8 @@ ok:
 				aggr = "seh";
 			else if(streq(fields.p[1], "Alg"))
 				aggr = "alg";
+			else if(streq(fields.p[1], "Panic"))
+				aggr = "panic";
 		}
 		if(hasprefix(lines.p[i], "}"))
 			aggr = nil;
@@ -273,6 +285,7 @@ ok:
 
 	bfree(&in);
 	bfree(&b);
+	bfree(&b1);
 	bfree(&out);
 	bfree(&exp);
 	vfree(&argv);
@@ -294,6 +307,10 @@ mkzsys(char *dir, char *file)
 	binit(&out);
 	
 	bwritestr(&out, "// auto generated by go tool dist\n\n");
+	if(streq(goos, "linux")) {
+		bwritestr(&out, "// +build !android\n\n");
+	}
+	
 	if(streq(goos, "windows")) {
 		bwritef(&out,
 			"// runtime·callbackasm is called by external code to\n"
@@ -346,13 +363,24 @@ mkzruntimedefs(char *dir, char *file)
 	vinit(&seen);
 	
 	bwritestr(&out, "// auto generated by go tool dist\n"
-		"\n"
+		"\n");
+
+	if(streq(goos, "linux")) {
+		bwritestr(&out, "// +build !android\n\n");
+	}
+	
+	bwritestr(&out,
 		"package runtime\n"
 		"import \"unsafe\"\n"
 		"var _ unsafe.Pointer\n"
 		"\n"
 	);
 
+	// Do not emit definitions for these.
+	vadd(&seen, "true");
+	vadd(&seen, "false");
+	vadd(&seen, "raceenabled");
+	vadd(&seen, "allgs");
 	
 	// Run 6c -D GOOS_goos -D GOARCH_goarch -I workdir -q -n -o workdir/runtimedefs
 	// on each of the runtimedefs C files.
@@ -363,6 +391,8 @@ mkzruntimedefs(char *dir, char *file)
 	vadd(&argv, bprintf(&b, "GOARCH_%s", goarch));
 	vadd(&argv, "-I");
 	vadd(&argv, bprintf(&b, "%s", workdir));
+	vadd(&argv, "-I");
+	vadd(&argv, bprintf(&b, "%s/pkg/%s_%s", goroot, goos, goarch));
 	vadd(&argv, "-q");
 	vadd(&argv, "-n");
 	vadd(&argv, "-o");
@@ -382,15 +412,15 @@ mkzruntimedefs(char *dir, char *file)
 	splitlines(&lines, bstr(&in));
 	for(i=0; i<lines.len; i++) {
 		p = lines.p[i];
-		// Drop comment, func, and const lines.
-		if(hasprefix(p, "//") || hasprefix(p, "const") || hasprefix(p, "func"))
+		// Drop comment and func lines.
+		if(hasprefix(p, "//") || hasprefix(p, "func"))
 			continue;
 		
 		// Note beginning of type or var decl, which can be multiline.
 		// Remove duplicates.  The linear check of seen here makes the
 		// whole processing quadratic in aggregate, but there are only
 		// about 100 declarations, so this is okay (and simple).
-		if(hasprefix(p, "type ") || hasprefix(p, "var ")) {
+		if(hasprefix(p, "type ") || hasprefix(p, "var ") || hasprefix(p, "const ")) {
 			splitfields(&fields, p);
 			if(fields.len < 2)
 				continue;
@@ -401,6 +431,17 @@ mkzruntimedefs(char *dir, char *file)
 			}
 			vadd(&seen, fields.p[1]);
 		}
+
+		// Const lines are printed in original case (usually upper). Add a leading _ as needed.
+		if(hasprefix(p, "const ")) {
+			if('A' <= p[6] && p[6] <= 'Z')
+				bwritestr(&out, "const _");
+			else
+				bwritestr(&out, "const ");
+			bwritestr(&out, p+6);
+			continue;
+		}
+
 		if(skip) {
 			if(hasprefix(p, "}"))
 				skip = 0;
@@ -409,6 +450,11 @@ mkzruntimedefs(char *dir, char *file)
 		
 		bwritestr(&out, p);
 	}
+
+	// Some windows specific const.
+	if(streq(goos, "windows")) {
+		bwritestr(&out, bprintf(&b, "const cb_max = %d\n", MAXWINCB));
+	}
 	
 	writefile(&out, file, 0);
 
diff --git a/src/cmd/dist/goc2c.c b/src/cmd/dist/goc2c.c
deleted file mode 100644
index 72cbc1be6..000000000
--- a/src/cmd/dist/goc2c.c
+++ /dev/null
@@ -1,833 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-#include "a.h"
-
-/*
- * Translate a .goc file into a .c file.  A .goc file is a combination
- * of a limited form of Go with C.
- */
-
-/*
-	package PACKAGENAME
-	{# line}
-	func NAME([NAME TYPE { , NAME TYPE }]) [(NAME TYPE { , NAME TYPE })] \{
-	  C code with proper brace nesting
-	\}
-*/
-
-/*
- * We generate C code which implements the function such that it can
- * be called from Go and executes the C code.
- */
-
-static char *input;
-static Buf *output;
-#define EOF -1
-
-enum
-{
-	use64bitint = 1,
-};
-
-static int
-xgetchar(void)
-{
-	int c;
-	
-	c = *input;
-	if(c == 0)
-		return EOF;
-	input++;
-	return c;
-}
-
-static void
-xungetc(void)
-{
-	input--;
-}
-
-static void
-xputchar(char c)
-{
-	bwrite(output, &c, 1);
-}
-
-static int
-xisspace(int c)
-{
-	return c == ' ' || c == '\t' || c == '\r' || c == '\n';
-}
-
-/* Whether we're emitting for gcc */
-static int gcc;
-
-/* File and line number */
-static const char *file;
-static unsigned int lineno;
-
-/* List of names and types.  */
-struct params {
-	struct params *next;
-	char *name;
-	char *type;
-};
-
-/* index into type_table */
-enum {
-	Bool,
-	Float,
-	Int,
-	Uint,
-	Uintptr,
-	String,
-	Slice,
-	Eface,
-	Complex128,
-	Float32,
-	Float64,
-};
-
-static struct {
-	char *name;
-	int size;
-	int rnd; // alignment
-} type_table[] = {
-	/* 
-	 * variable sized first, for easy replacement.
-	 * order matches enum above.
-	 * default is 32-bit architecture sizes.
-	 * spelling as in package runtime, so intgo/uintgo not int/uint.
-	 */
-	{"bool",	1},
-	{"float",	4},
-	{"intgo",		4},
-	{"uintgo",	4},
-	{"uintptr",	4},
-	{"String",	8},
-	{"Slice",	12},
-	{"Eface",	8},
-	{"Complex128", 16},
-
-	/* fixed size */
-	{"float32",	4},
-	{"float64",	8},
-	{"byte",	1},
-	{"int8",	1},
-	{"uint8",	1},
-	{"int16",	2},
-	{"uint16",	2},
-	{"int32",	4},
-	{"rune",	4},
-	{"uint32",	4},
-	{"int64",	8},
-	{"uint64",	8},
-
-	{nil, 0},
-};
-
-/* Fixed structure alignment (non-gcc only) */
-int structround = 4;
-
-/* Unexpected EOF.  */
-static void
-bad_eof(void)
-{
-	fatal("%s:%d: unexpected EOF\n", file, lineno);
-}
-
-/* Free a list of parameters.  */
-static void
-free_params(struct params *p)
-{
-	while (p != nil) {
-		struct params *next;
-
-		next = p->next;
-		xfree(p->name);
-		xfree(p->type);
-		xfree(p);
-		p = next;
-	}
-}
-
-/* Read a character, tracking lineno.  */
-static int
-getchar_update_lineno(void)
-{
-	int c;
-
-	c = xgetchar();
-	if (c == '\n')
-		++lineno;
-	return c;
-}
-
-/* Read a character, giving an error on EOF, tracking lineno.  */
-static int
-getchar_no_eof(void)
-{
-	int c;
-
-	c = getchar_update_lineno();
-	if (c == EOF)
-		bad_eof();
-	return c;
-}
-
-/* Read a character, skipping comments.  */
-static int
-getchar_skipping_comments(void)
-{
-	int c;
-
-	while (1) {
-		c = getchar_update_lineno();
-		if (c != '/')
-			return c;
-
-		c = xgetchar();
-		if (c == '/') {
-			do {
-				c = getchar_update_lineno();
-			} while (c != EOF && c != '\n');
-			return c;
-		} else if (c == '*') {
-			while (1) {
-				c = getchar_update_lineno();
-				if (c == EOF)
-					return EOF;
-				if (c == '*') {
-					do {
-						c = getchar_update_lineno();
-					} while (c == '*');
-					if (c == '/')
-						break;
-				}
-			}
-		} else {
-			xungetc();
-			return '/';
-		}
-	}
-}
-
-/*
- * Read and return a token.  Tokens are string or character literals
- * or else delimited by whitespace or by [(),{}].
- * The latter are all returned as single characters.
- */
-static char *
-read_token(void)
-{
-	int c, q;
-	char *buf;
-	unsigned int alc, off;
-	char* delims = "(),{}";
-
-	while (1) {
-		c = getchar_skipping_comments();
-		if (c == EOF)
-			return nil;
-		if (!xisspace(c))
-			break;
-	}
-	alc = 16;
-	buf = xmalloc(alc + 1);
-	off = 0;
-	if(c == '"' || c == '\'') {
-		q = c;
-		buf[off] = c;
-		++off;
-		while (1) {
-			if (off+2 >= alc) { // room for c and maybe next char
-				alc *= 2;
-				buf = xrealloc(buf, alc + 1);
-			}
-			c = getchar_no_eof();
-			buf[off] = c;
-			++off;
-			if(c == q)
-				break;
-			if(c == '\\') {
-				buf[off] = getchar_no_eof();
-				++off;
-			}
-		}
-	} else if (xstrrchr(delims, c) != nil) {
-		buf[off] = c;
-		++off;
-	} else {
-		while (1) {
-			if (off >= alc) {
-				alc *= 2;
-				buf = xrealloc(buf, alc + 1);
-			}
-			buf[off] = c;
-			++off;
-			c = getchar_skipping_comments();
-			if (c == EOF)
-				break;
-			if (xisspace(c) || xstrrchr(delims, c) != nil) {
-				if (c == '\n')
-					lineno--;
-				xungetc();
-				break;
-			}
-		}
-	}
-	buf[off] = '\0';
-	return buf;
-}
-
-/* Read a token, giving an error on EOF.  */
-static char *
-read_token_no_eof(void)
-{
-	char *token = read_token();
-	if (token == nil)
-		bad_eof();
-	return token;
-}
-
-/* Read the package clause, and return the package name.  */
-static char *
-read_package(void)
-{
-	char *token;
-
-	token = read_token_no_eof();
-	if (token == nil)
-		fatal("%s:%d: no token\n", file, lineno);
-	if (!streq(token, "package")) {
-		fatal("%s:%d: expected \"package\", got \"%s\"\n",
-			file, lineno, token);
-	}
-	return read_token_no_eof();
-}
-
-/* Read and copy preprocessor lines.  */
-static void
-read_preprocessor_lines(void)
-{
-	int first;
-	
-	first = 1;
-	while (1) {
-		int c;
-
-		do {
-			c = getchar_skipping_comments();
-		} while (xisspace(c));
-		if (c != '#') {
-			xungetc();
-			break;
-		}
-		if(first) {
-			first = 0;
-			xputchar('\n');
-		}
-		xputchar(c);
-		do {
-			c = getchar_update_lineno();
-			xputchar(c);
-		} while (c != '\n');
-	}
-}
-
-/*
- * Read a type in Go syntax and return a type in C syntax.  We only
- * permit basic types and pointers.
- */
-static char *
-read_type(void)
-{
-	char *p, *op, *q;
-	int pointer_count;
-	unsigned int len;
-
-	p = read_token_no_eof();
-	if (*p != '*' && !streq(p, "int") && !streq(p, "uint"))
-		return p;
-	op = p;
-	pointer_count = 0;
-	while (*p == '*') {
-		++pointer_count;
-		++p;
-	}
-	len = xstrlen(p);
-	q = xmalloc(len + 2 + pointer_count + 1);
-	xmemmove(q, p, len);
-
-	// Turn int/uint into intgo/uintgo.
-	if((len == 3 && xmemcmp(q, "int", 3) == 0) || (len == 4 && xmemcmp(q, "uint", 4) == 0)) {
-		q[len++] = 'g';
-		q[len++] = 'o';
-	}
-
-	while (pointer_count-- > 0)
-		q[len++] = '*';
-	
-	q[len] = '\0';
-	xfree(op);
-	return q;
-}
-
-/* Return the size of the given type. */
-static int
-type_size(char *p, int *rnd)
-{
-	int i;
-
-	if(p[xstrlen(p)-1] == '*') {
-		*rnd = type_table[Uintptr].rnd;
-		return type_table[Uintptr].size;
-	}
-
-	if(streq(p, "Iface"))
-		p = "Eface";
-
-	for(i=0; type_table[i].name; i++)
-		if(streq(type_table[i].name, p)) {
-			*rnd = type_table[i].rnd;
-			return type_table[i].size;
-		}
-	fatal("%s:%d: unknown type %s\n", file, lineno, p);
-	return 0;
-}
-
-/*
- * Read a list of parameters.  Each parameter is a name and a type.
- * The list ends with a ')'.  We have already read the '('.
- */
-static struct params *
-read_params(int *poffset)
-{
-	char *token;
-	struct params *ret, **pp, *p;
-	int offset, size, rnd;
-
-	ret = nil;
-	pp = &ret;
-	token = read_token_no_eof();
-	offset = 0;
-	if (!streq(token, ")")) {
-		while (1) {
-			p = xmalloc(sizeof(struct params));
-			p->name = token;
-			p->next = nil;
-			*pp = p;
-			pp = &p->next;
-
-			if(streq(token, "...")) {
-				p->type = xstrdup("");
-			} else {
-				p->type = read_type();
-				rnd = 0;
-				size = type_size(p->type, &rnd);
-				if(rnd > structround)
-					rnd = structround;
-				if(offset%rnd)
-					offset += rnd - offset%rnd;
-				offset += size;
-			}
-
-			token = read_token_no_eof();
-			if (!streq(token, ","))
-				break;
-			token = read_token_no_eof();
-		}
-	}
-	if (!streq(token, ")")) {
-		fatal("%s:%d: expected '('\n",
-			file, lineno);
-	}
-	if (poffset != nil)
-		*poffset = offset;
-	return ret;
-}
-
-/*
- * Read a function header.  This reads up to and including the initial
- * '{' character.  Returns 1 if it read a header, 0 at EOF.
- */
-static int
-read_func_header(char **name, struct params **params, int *paramwid, struct params **rets)
-{
-	int lastline;
-	char *token;
-
-	lastline = -1;
-	while (1) {
-		read_preprocessor_lines();
-		token = read_token();
-		if (token == nil)
-			return 0;
-		if (streq(token, "func")) {
-			if(lastline != -1)
-				bwritef(output, "\n");
-			break;
-		}
-		if (lastline != lineno) {
-			if (lastline == lineno-1)
-				bwritef(output, "\n");
-			else
-				bwritef(output, "\n#line %d \"%s\"\n", lineno, file);
-			lastline = lineno;
-		}
-		bwritef(output, "%s ", token);
-	}
-
-	*name = read_token_no_eof();
-
-	token = read_token();
-	if (token == nil || !streq(token, "(")) {
-		fatal("%s:%d: expected \"(\"\n",
-			file, lineno);
-	}
-	*params = read_params(paramwid);
-
-	token = read_token();
-	if (token == nil || !streq(token, "("))
-		*rets = nil;
-	else {
-		*rets = read_params(nil);
-		token = read_token();
-	}
-	if (token == nil || !streq(token, "{")) {
-		fatal("%s:%d: expected \"{\"\n",
-			file, lineno);
-	}
-	return 1;
-}
-
-/* Write out parameters.  */
-static void
-write_params(struct params *params, int *first)
-{
-	struct params *p;
-
-	for (p = params; p != nil; p = p->next) {
-		if (*first)
-			*first = 0;
-		else
-			bwritef(output, ", ");
-		bwritef(output, "%s %s", p->type, p->name);
-	}
-}
-
-/* Write a 6g function header.  */
-static void
-write_6g_func_header(char *package, char *name, struct params *params,
-		     int paramwid, struct params *rets)
-{
-	int first, n;
-	struct params *p;
-
-	bwritef(output, "void\n");
-	if(!contains(name, "·"))
-		bwritef(output, "%s·", package);
-	bwritef(output, "%s(", name);
-
-	first = 1;
-	write_params(params, &first);
-
-	/* insert padding to align output struct */
-	if(rets != nil && paramwid%structround != 0) {
-		n = structround - paramwid%structround;
-		if(n & 1)
-			bwritef(output, ", uint8");
-		if(n & 2)
-			bwritef(output, ", uint16");
-		if(n & 4)
-			bwritef(output, ", uint32");
-	}
-
-	write_params(rets, &first);
-	bwritef(output, ")\n{\n");
-	
-	for (p = rets; p != nil; p = p->next) {
-		if(streq(p->name, "..."))
-			continue;
-		if(streq(p->type, "Slice"))
-			bwritef(output, "\t%s.array = 0;\n\t%s.len = 0;\n\t%s.cap = 0;\n", p->name, p->name, p->name);
-		else if(streq(p->type, "String"))
-			bwritef(output, "\t%s.str = 0;\n\t%s.len = 0;\n", p->name, p->name);
-		else if(streq(p->type, "Eface"))
-			bwritef(output, "\t%s.type = 0;\n\t%s.data = 0;\n", p->name, p->name);
-		else if(streq(p->type, "Iface"))
-			bwritef(output, "\t%s.tab = 0;\n\t%s.data = 0;\n", p->name, p->name);
-		else if(streq(p->type, "Complex128"))
-			bwritef(output, "\t%s.real = 0;\n\t%s.imag = 0;\n", p->name, p->name);
-		else
-			bwritef(output, "\t%s = 0;\n", p->name);
-		bwritef(output, "\tFLUSH(&%s);\n", p->name);
-	}
-}
-
-/* Write a 6g function trailer.  */
-static void
-write_6g_func_trailer(struct params *rets)
-{
-	struct params *p;
-
-	for (p = rets; p != nil; p = p->next)
-		if(!streq(p->name, "..."))
-			bwritef(output, "\tFLUSH(&%s);\n", p->name);
-	bwritef(output, "}\n");
-}
-
-/* Define the gcc function return type if necessary.  */
-static void
-define_gcc_return_type(char *package, char *name, struct params *rets)
-{
-	struct params *p;
-
-	if (rets == nil || rets->next == nil)
-		return;
-	bwritef(output, "struct %s_%s_ret {\n", package, name);
-	for (p = rets; p != nil; p = p->next)
-		bwritef(output, "  %s %s;\n", p->type, p->name);
-	bwritef(output, "};\n");
-}
-
-/* Write out the gcc function return type.  */
-static void
-write_gcc_return_type(char *package, char *name, struct params *rets)
-{
-	if (rets == nil)
-		bwritef(output, "void");
-	else if (rets->next == nil)
-		bwritef(output, "%s", rets->type);
-	else
-		bwritef(output, "struct %s_%s_ret", package, name);
-}
-
-/* Write out a gcc function header.  */
-static void
-write_gcc_func_header(char *package, char *name, struct params *params,
-		      struct params *rets)
-{
-	int first;
-	struct params *p;
-
-	define_gcc_return_type(package, name, rets);
-	write_gcc_return_type(package, name, rets);
-	bwritef(output, " %s_%s(", package, name);
-	first = 1;
-	write_params(params, &first);
-	bwritef(output, ") asm (\"%s.%s\");\n", package, name);
-	write_gcc_return_type(package, name, rets);
-	bwritef(output, " %s_%s(", package, name);
-	first = 1;
-	write_params(params, &first);
-	bwritef(output, ")\n{\n");
-	for (p = rets; p != nil; p = p->next)
-		bwritef(output, "  %s %s;\n", p->type, p->name);
-}
-
-/* Write out a gcc function trailer.  */
-static void
-write_gcc_func_trailer(char *package, char *name, struct params *rets)
-{
-	if (rets == nil) {
-		// nothing to do
-	}
-	else if (rets->next == nil)
-		bwritef(output, "return %s;\n", rets->name);
-	else {
-		struct params *p;
-
-		bwritef(output, "  {\n    struct %s_%s_ret __ret;\n", package, name);
-		for (p = rets; p != nil; p = p->next)
-			bwritef(output, "    __ret.%s = %s;\n", p->name, p->name);
-		bwritef(output, "    return __ret;\n  }\n");
-	}
-	bwritef(output, "}\n");
-}
-
-/* Write out a function header.  */
-static void
-write_func_header(char *package, char *name,
-		  struct params *params, int paramwid,
-		  struct params *rets)
-{
-	if (gcc)
-		write_gcc_func_header(package, name, params, rets);
-	else
-		write_6g_func_header(package, name, params, paramwid, rets);
-	bwritef(output, "#line %d \"%s\"\n", lineno, file);
-}
-
-/* Write out a function trailer.  */
-static void
-write_func_trailer(char *package, char *name,
-		   struct params *rets)
-{
-	if (gcc)
-		write_gcc_func_trailer(package, name, rets);
-	else
-		write_6g_func_trailer(rets);
-}
-
-/*
- * Read and write the body of the function, ending in an unnested }
- * (which is read but not written).
- */
-static void
-copy_body(void)
-{
-	int nesting = 0;
-	while (1) {
-		int c;
-
-		c = getchar_no_eof();
-		if (c == '}' && nesting == 0)
-			return;
-		xputchar(c);
-		switch (c) {
-		default:
-			break;
-		case '{':
-			++nesting;
-			break;
-		case '}':
-			--nesting;
-			break;
-		case '/':
-			c = getchar_update_lineno();
-			xputchar(c);
-			if (c == '/') {
-				do {
-					c = getchar_no_eof();
-					xputchar(c);
-				} while (c != '\n');
-			} else if (c == '*') {
-				while (1) {
-					c = getchar_no_eof();
-					xputchar(c);
-					if (c == '*') {
-						do {
-							c = getchar_no_eof();
-							xputchar(c);
-						} while (c == '*');
-						if (c == '/')
-							break;
-					}
-				}
-			}
-			break;
-		case '"':
-		case '\'':
-			{
-				int delim = c;
-				do {
-					c = getchar_no_eof();
-					xputchar(c);
-					if (c == '\\') {
-						c = getchar_no_eof();
-						xputchar(c);
-						c = '\0';
-					}
-				} while (c != delim);
-			}
-			break;
-		}
-	}
-}
-
-/* Process the entire file.  */
-static void
-process_file(void)
-{
-	char *package, *name, *p, *n;
-	struct params *params, *rets;
-	int paramwid;
-
-	package = read_package();
-	read_preprocessor_lines();
-	while (read_func_header(&name, &params, &paramwid, &rets)) {
-		// name may have a package override already
-		n = xstrstr(name, "·");
-		if(n != nil) {
-			p = xmalloc(n - name + 1);
-			xmemmove(p, name, n - name);
-			p[n - name] = 0;
-			n += xstrlen("·");
-		} else {
-			p = package;
-			n = name;
-		}
-		write_func_header(p, n, params, paramwid, rets);
-		copy_body();
-		write_func_trailer(p, n, rets);
-		xfree(name);
-		if(p != package) xfree(p);
-		free_params(params);
-		free_params(rets);
-	}
-	xfree(package);
-}
-
-void
-goc2c(char *goc, char *c)
-{
-	int i;
-	Buf in, out;
-	
-	binit(&in);
-	binit(&out);
-	
-	file = goc;
-	readfile(&in, goc);
-
-	// TODO: set gcc=1 when using gcc
-
-	if(!gcc) {
-		if(contains(goarch, "64p32")) {
-			type_table[Uintptr].size = 4;
-			type_table[Int].size = 4;
-			structround = 8;
-		} else if(contains(goarch, "64")) {
-			type_table[Uintptr].size = 8;
-			if(use64bitint) {
-				type_table[Int].size = 8;
-			} else {
-				type_table[Int].size = 4;
-			}
-			structround = 8;
-		} else {
-			// NOTE: These are set in the initializer,
-			// but they might have been changed by a
-			// previous invocation of goc2c, so we have
-			// to restore them.
-			type_table[Uintptr].size = 4;
-			type_table[Int].size = 4;
-			structround = 4;
-		}
-
-		type_table[Uint].size = type_table[Int].size;
-		type_table[Slice].size = type_table[Uintptr].size+2*type_table[Int].size;
-		type_table[Eface].size = 2*type_table[Uintptr].size;
-		type_table[String].size = 2*type_table[Uintptr].size;
-
-		for(i=0; i<nelem(type_table); i++)
-			type_table[i].rnd = type_table[i].size;
-
-		type_table[String].rnd = type_table[Uintptr].rnd;
-		type_table[Slice].rnd = type_table[Uintptr].rnd;
-		type_table[Eface].rnd = type_table[Uintptr].rnd;
-		type_table[Complex128].rnd = type_table[Float64].rnd;
-	}
-
-	bprintf(&out, "// auto generated by go tool dist\n// goos=%s goarch=%s\n\n", goos, goarch);
-	input = bstr(&in);
-	output = &out;
-
-	lineno = 1;
-	process_file();
-	
-	writefile(&out, c, 0);
-}
diff --git a/src/cmd/dist/plan9.c b/src/cmd/dist/plan9.c
index 8d492ebc6..e4bf25147 100644
--- a/src/cmd/dist/plan9.c
+++ b/src/cmd/dist/plan9.c
@@ -23,7 +23,7 @@ bprintf(Buf *b, char *fmt, ...)
 {
 	va_list arg;
 	char buf[4096];
-	
+
 	breset(b);
 	va_start(arg, fmt);
 	vsnprintf(buf, sizeof buf, fmt, arg);
@@ -572,10 +572,10 @@ bool
 hassuffix(char *p, char *suffix)
 {
 	int np, ns;
-	
+
 	np = strlen(p);
 	ns = strlen(suffix);
-	return np >= ns && strcmp(p+np-ns, suffix) == 0;
+	return np >= ns && streq(p+np-ns, suffix);
 }
 
 // hasprefix reports whether p begins with prefix.
diff --git a/src/cmd/dist/unix.c b/src/cmd/dist/unix.c
index 668b189ca..893ed5cdd 100644
--- a/src/cmd/dist/unix.c
+++ b/src/cmd/dist/unix.c
@@ -431,7 +431,7 @@ xremoveall(char *p)
 	}
 	
 	bfree(&b);
-	vfree(&dir);	
+	vfree(&dir);
 }
 
 // xreaddir replaces dst with a list of the names of the files in dir.
@@ -441,13 +441,13 @@ xreaddir(Vec *dst, char *dir)
 {
 	DIR *d;
 	struct dirent *dp;
-	
+
 	vreset(dst);
 	d = opendir(dir);
 	if(d == nil)
 		fatal("opendir %s: %s", dir, strerror(errno));
 	while((dp = readdir(d)) != nil) {
-		if(strcmp(dp->d_name, ".") == 0 || strcmp(dp->d_name, "..") == 0)
+		if(streq(dp->d_name, ".") || streq(dp->d_name, ".."))
 			continue;
 		vadd(dst, dp->d_name);
 	}
@@ -461,7 +461,7 @@ xworkdir(void)
 {
 	Buf b;
 	char *p;
-	
+
 	binit(&b);
 
 	xgetenv(&b, "TMPDIR");
@@ -546,10 +546,10 @@ bool
 hassuffix(char *p, char *suffix)
 {
 	int np, ns;
-	
+
 	np = strlen(p);
 	ns = strlen(suffix);
-	return np >= ns && strcmp(p+np-ns, suffix) == 0;
+	return np >= ns && streq(p+np-ns, suffix);
 }
 
 // hasprefix reports whether p begins with prefix.
@@ -716,7 +716,7 @@ main(int argc, char **argv)
 			fatal("unknown architecture: %s", u.machine);
 	}
 
-	if(strcmp(gohostarch, "arm") == 0)
+	if(streq(gohostarch, "arm"))
 		maxnbg = 1;
 
 	// The OS X 10.6 linker does not support external linking mode.
@@ -728,7 +728,7 @@ main(int argc, char **argv)
 	//
 	// Roughly, OS X 10.N shows up as uname release (N+4),
 	// so OS X 10.6 is uname version 10 and OS X 10.8 is uname version 12.
-	if(strcmp(gohostos, "darwin") == 0) {
+	if(streq(gohostos, "darwin")) {
 		if(uname(&u) < 0)
 			fatal("uname: %s", strerror(errno));
 		osx = atoi(u.release) - 4;
diff --git a/src/cmd/dist/windows.c b/src/cmd/dist/windows.c
index 2839c4bc5..1102adff5 100644
--- a/src/cmd/dist/windows.c
+++ b/src/cmd/dist/windows.c
@@ -770,10 +770,10 @@ bool
 hassuffix(char *p, char *suffix)
 {
 	int np, ns;
-	
+
 	np = strlen(p);
 	ns = strlen(suffix);
-	return np >= ns && strcmp(p+np-ns, suffix) == 0;
+	return np >= ns && streq(p+np-ns, suffix);
 }
 
 bool
diff --git a/src/cmd/fix/doc.go b/src/cmd/fix/doc.go
index 5de3e08c5..057016957 100644
--- a/src/cmd/fix/doc.go
+++ b/src/cmd/fix/doc.go
@@ -27,7 +27,7 @@ rewrites are idempotent, so that it is safe to apply fix to updated
 or partially updated code even without using the -r flag.
 
 Fix prints the full list of fixes it can apply in its help output;
-to see them, run go tool fix -?.
+to see them, run go tool fix -help.
 
 Fix does not make backup copies of the files that it edits.
 Instead, use a version control system's ``diff'' functionality to inspect
diff --git a/src/cmd/gc/builtin.c b/src/cmd/gc/builtin.c
index 4808269b7..60b7c2f97 100644
--- a/src/cmd/gc/builtin.c
+++ b/src/cmd/gc/builtin.c
@@ -9,11 +9,12 @@ char *runtimeimport =
 	"func @\"\".throwreturn ()\n"
 	"func @\"\".throwinit ()\n"
 	"func @\"\".panicwrap (? string, ? string, ? string)\n"
-	"func @\"\".panic (? interface {})\n"
-	"func @\"\".recover (? *int32) (? interface {})\n"
+	"func @\"\".gopanic (? interface {})\n"
+	"func @\"\".gorecover (? *int32) (? interface {})\n"
 	"func @\"\".printbool (? bool)\n"
 	"func @\"\".printfloat (? float64)\n"
 	"func @\"\".printint (? int64)\n"
+	"func @\"\".printhex (? uint64)\n"
 	"func @\"\".printuint (? uint64)\n"
 	"func @\"\".printcomplex (? complex128)\n"
 	"func @\"\".printstring (? string)\n"
@@ -64,7 +65,6 @@ char *runtimeimport =
 	"func @\"\".efaceeq (@\"\".i1·2 any, @\"\".i2·3 any) (@\"\".ret·1 bool)\n"
 	"func @\"\".ifacethash (@\"\".i1·2 any) (@\"\".ret·1 uint32)\n"
 	"func @\"\".efacethash (@\"\".i1·2 any) (@\"\".ret·1 uint32)\n"
-	"func @\"\".equal (@\"\".typ·2 *byte, @\"\".x1·3 any, @\"\".x2·4 any) (@\"\".ret·1 bool)\n"
 	"func @\"\".makemap (@\"\".mapType·2 *byte, @\"\".hint·3 int64) (@\"\".hmap·1 map[any]any)\n"
 	"func @\"\".mapaccess1 (@\"\".mapType·2 *byte, @\"\".hmap·3 map[any]any, @\"\".key·4 *any) (@\"\".val·1 *any)\n"
 	"func @\"\".mapaccess1_fast32 (@\"\".mapType·2 *byte, @\"\".hmap·3 map[any]any, @\"\".key·4 any) (@\"\".val·1 *any)\n"
@@ -96,12 +96,12 @@ char *runtimeimport =
 	"func @\"\".makeslice (@\"\".typ·2 *byte, @\"\".nel·3 int64, @\"\".cap·4 int64) (@\"\".ary·1 []any)\n"
 	"func @\"\".growslice (@\"\".typ·2 *byte, @\"\".old·3 []any, @\"\".n·4 int64) (@\"\".ary·1 []any)\n"
 	"func @\"\".memmove (@\"\".to·1 *any, @\"\".frm·2 *any, @\"\".length·3 uintptr)\n"
-	"func @\"\".memequal (@\"\".eq·1 *bool, @\"\".size·2 uintptr, @\"\".x·3 *any, @\"\".y·4 *any)\n"
-	"func @\"\".memequal8 (@\"\".eq·1 *bool, @\"\".size·2 uintptr, @\"\".x·3 *any, @\"\".y·4 *any)\n"
-	"func @\"\".memequal16 (@\"\".eq·1 *bool, @\"\".size·2 uintptr, @\"\".x·3 *any, @\"\".y·4 *any)\n"
-	"func @\"\".memequal32 (@\"\".eq·1 *bool, @\"\".size·2 uintptr, @\"\".x·3 *any, @\"\".y·4 *any)\n"
-	"func @\"\".memequal64 (@\"\".eq·1 *bool, @\"\".size·2 uintptr, @\"\".x·3 *any, @\"\".y·4 *any)\n"
-	"func @\"\".memequal128 (@\"\".eq·1 *bool, @\"\".size·2 uintptr, @\"\".x·3 *any, @\"\".y·4 *any)\n"
+	"func @\"\".memequal (@\"\".x·2 *any, @\"\".y·3 *any, @\"\".size·4 uintptr) (? bool)\n"
+	"func @\"\".memequal8 (@\"\".x·2 *any, @\"\".y·3 *any, @\"\".size·4 uintptr) (? bool)\n"
+	"func @\"\".memequal16 (@\"\".x·2 *any, @\"\".y·3 *any, @\"\".size·4 uintptr) (? bool)\n"
+	"func @\"\".memequal32 (@\"\".x·2 *any, @\"\".y·3 *any, @\"\".size·4 uintptr) (? bool)\n"
+	"func @\"\".memequal64 (@\"\".x·2 *any, @\"\".y·3 *any, @\"\".size·4 uintptr) (? bool)\n"
+	"func @\"\".memequal128 (@\"\".x·2 *any, @\"\".y·3 *any, @\"\".size·4 uintptr) (? bool)\n"
 	"func @\"\".int64div (? int64, ? int64) (? int64)\n"
 	"func @\"\".uint64div (? uint64, ? uint64) (? uint64)\n"
 	"func @\"\".int64mod (? int64, ? int64) (? int64)\n"
diff --git a/src/cmd/gc/bv.c b/src/cmd/gc/bv.c
index 0e8f8d473..cfd1cd281 100644
--- a/src/cmd/gc/bv.c
+++ b/src/cmd/gc/bv.c
@@ -108,6 +108,9 @@ bvnext(Bvec *bv, int32 i)
 {
 	uint32 w;
 
+	if(i >= bv->n)
+		return -1;
+
 	// Jump i ahead to next word with bits.
 	if((bv->b[i>>WORDSHIFT]>>(i&WORDMASK)) == 0) {
 		i &= ~WORDMASK;
@@ -117,7 +120,7 @@ bvnext(Bvec *bv, int32 i)
 	}
 	if(i >= bv->n)
 		return -1;
-	
+
 	// Find 1 bit.
 	w = bv->b[i>>WORDSHIFT]>>(i&WORDMASK);
 	while((w&1) == 0) {
diff --git a/src/cmd/gc/const.c b/src/cmd/gc/const.c
index c01784a81..e418b9c56 100644
--- a/src/cmd/gc/const.c
+++ b/src/cmd/gc/const.c
@@ -1566,7 +1566,6 @@ isgoconst(Node *n)
 	case ORSH:
 	case OSUB:
 	case OXOR:
-	case OCONV:
 	case OIOTA:
 	case OCOMPLEX:
 	case OREAL:
@@ -1574,7 +1573,12 @@ isgoconst(Node *n)
 		if(isgoconst(n->left) && (n->right == N || isgoconst(n->right)))
 			return 1;
 		break;
-	
+
+	case OCONV:
+		if(okforconst[n->type->etype] && isgoconst(n->left))
+			return 1;
+		break;
+
 	case OLEN:
 	case OCAP:
 		l = n->left;
diff --git a/src/cmd/gc/fmt.c b/src/cmd/gc/fmt.c
index 951170aef..98556a658 100644
--- a/src/cmd/gc/fmt.c
+++ b/src/cmd/gc/fmt.c
@@ -1153,7 +1153,7 @@ exprfmt(Fmt *f, Node *n, int prec)
 		case Csend:
 			return fmtprint(f, "chan<- %N", n->left);
 		default:
-			if(n->left != N && n->left->op == TCHAN && n->left->sym == S && n->left->etype == Crecv)
+			if(n->left != N && n->left->op == OTCHAN && n->left->sym == S && n->left->etype == Crecv)
 				return fmtprint(f, "chan (%N)", n->left);
 			else
 				return fmtprint(f, "chan %N", n->left);
diff --git a/src/cmd/gc/gen.c b/src/cmd/gc/gen.c
index 908a5e53d..86acd8825 100644
--- a/src/cmd/gc/gen.c
+++ b/src/cmd/gc/gen.c
@@ -806,7 +806,8 @@ cgen_eface(Node *n, Node *res)
 void
 cgen_slice(Node *n, Node *res)
 {
-	Node src, dst, *cap, *len, *offs, *add, *base;
+	Node src, dst, *cap, *len, *offs, *add, *base, *tmpcap, *tmplen, *cmp, con;
+	Prog *p1, *p2;
 
 	cap = n->list->n;
 	len = n->list->next->n;
@@ -823,6 +824,11 @@ cgen_slice(Node *n, Node *res)
 	// garbage collector can see.
 	
 	base = temp(types[TUINTPTR]);
+	tmplen = temp(types[TINT]);
+	if(n->op != OSLICESTR)
+		tmpcap = temp(types[TINT]);
+	else
+		tmpcap = tmplen;
 
 	if(isnil(n->left)) {
 		tempname(&src, n->left->type);
@@ -837,43 +843,62 @@ cgen_slice(Node *n, Node *res)
 			fatal("slicearr is supposed to work on pointer: %+N\n", n);
 		cgen(&src, base);
 		cgen_checknil(base);
-		if(offs != N) {
-			add = nod(OADD, base, offs);
-			typecheck(&add, Erv);
-			cgen(add, base);
-		}
-	} else if(offs == N) {
-		src.type = types[tptr];
-		cgen(&src, base);
 	} else {
 		src.type = types[tptr];
-		add = nod(OADDPTR, &src, offs);
-		typecheck(&add, Erv);
-		cgen(add, base);
+		cgen(&src, base);
 	}
 	
 	// committed to the update
 	gvardef(res);
 
+	// compute len and cap.
+	// len = n-i, cap = m-i, and offs = i*width.
+	// computing offs last lets the multiply overwrite i.
+	cgen(len, tmplen);
+	if(n->op != OSLICESTR)
+		cgen(cap, tmpcap);
+
+	// if new cap != 0 { base += add }
+	// This avoids advancing base past the end of the underlying array/string,
+	// so that it cannot point at the next object in memory.
+	// If cap == 0, the base doesn't matter except insofar as it is 0 or non-zero.
+	// In essence we are replacing x[i:j:k] where i == j == k
+	// or x[i:j] where i == j == cap(x) with x[0:0:0].
+	if(offs != N) {
+		p1 = gjmp(P);
+		p2 = gjmp(P);
+		patch(p1, pc);
+
+		nodconst(&con, tmpcap->type, 0);
+		cmp = nod(OEQ, tmpcap, &con);
+		typecheck(&cmp, Erv);
+		bgen(cmp, 1, -1, p2);
+
+		add = nod(OADD, base, offs);
+		typecheck(&add, Erv);
+		cgen(add, base);
+
+		patch(p2, pc);
+	}
+
 	// dst.array = src.array  [ + lo *width ]
 	dst = *res;
 	dst.xoffset += Array_array;
 	dst.type = types[tptr];
-	
 	cgen(base, &dst);
 
 	// dst.len = hi [ - lo ]
 	dst = *res;
 	dst.xoffset += Array_nel;
 	dst.type = types[simtype[TUINT]];
-	cgen(len, &dst);
+	cgen(tmplen, &dst);
 
 	if(n->op != OSLICESTR) {
 		// dst.cap = cap [ - lo ]
 		dst = *res;
 		dst.xoffset += Array_cap;
 		dst.type = types[simtype[TUINT]];
-		cgen(cap, &dst);
+		cgen(tmpcap, &dst);
 	}
 }
 
diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index c3da5f636..12c1e9853 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -447,7 +447,6 @@ enum
 	OSUB,	// x - y
 	OOR,	// x | y
 	OXOR,	// x ^ y
-	OADDPTR,	// ptr + uintptr, inserted by compiler only, used to avoid unsafe type changes during codegen
 	OADDSTR,	// s + "foo"
 	OADDR,	// &x
 	OANDAND,	// b0 && b1
@@ -1169,6 +1168,7 @@ void	cgen_callmeth(Node *n, int proc);
 void	cgen_eface(Node* n, Node* res);
 void	cgen_slice(Node* n, Node* res);
 void	clearlabels(void);
+void	clearslim(Node*);
 void	checklabels(void);
 int	dotoffset(Node *n, int64 *oary, Node **nn);
 void	gen(Node *n);
@@ -1363,6 +1363,7 @@ int	is64(Type *t);
 int	isbadimport(Strlit *s);
 int	isblank(Node *n);
 int	isblanksym(Sym *s);
+int	isdirectiface(Type*);
 int	isfixedarray(Type *t);
 int	isideal(Type *t);
 int	isinter(Type *t);
diff --git a/src/cmd/gc/mparith1.c b/src/cmd/gc/mparith1.c
index 1519caec7..d33a81e09 100644
--- a/src/cmd/gc/mparith1.c
+++ b/src/cmd/gc/mparith1.c
@@ -591,7 +591,7 @@ Fconv(Fmt *fp)
 			d = mpgetflt(fvp);
 			if(d >= 0 && (fp->flags & FmtSign))
 				fmtprint(fp, "+");
-			return fmtprint(fp, "%g", d, exp, fvp);
+			return fmtprint(fp, "%g", d);
 		}
 		
 		// very out of range. compute decimal approximation by hand.
diff --git a/src/cmd/gc/mparith3.c b/src/cmd/gc/mparith3.c
index 95618f1c6..6afd75c02 100644
--- a/src/cmd/gc/mparith3.c
+++ b/src/cmd/gc/mparith3.c
@@ -251,8 +251,8 @@ mpgetfltN(Mpflt *a, int prec, int bias)
 		s = minexp - e;
 		if(s > prec+1)
 			s = prec+1;
-		if((v & ((1<<s)-1)) != 0)
-			v |= 1<<s;
+		if((v & ((1ULL<<s)-1)) != 0)
+			v |= 1ULL<<s;
 		v >>= s;
 		e = minexp;
 	}
diff --git a/src/cmd/gc/order.c b/src/cmd/gc/order.c
index 30dbc7dac..d11e9828c 100644
--- a/src/cmd/gc/order.c
+++ b/src/cmd/gc/order.c
@@ -593,7 +593,10 @@ orderstmt(Node *n, Order *order)
 		orderexpr(&n->rlist->n->left, order);  // arg to recv
 		ch = n->rlist->n->left->type;
 		tmp1 = ordertemp(ch->type, order, haspointers(ch->type));
-		tmp2 = ordertemp(types[TBOOL], order, 0);
+		if(!isblank(n->list->next->n))
+			tmp2 = ordertemp(n->list->next->n->type, order, 0);
+		else
+			tmp2 = ordertemp(types[TBOOL], order, 0);
 		order->out = list(order->out, n);
 		r = nod(OAS, n->list->n, tmp1);
 		typecheck(&r, Etop);
@@ -768,6 +771,12 @@ orderstmt(Node *n, Order *order)
 		// Special: clean case temporaries in each block entry.
 		// Select must enter one of its blocks, so there is no
 		// need for a cleaning at the end.
+		// Doubly special: evaluation order for select is stricter
+		// than ordinary expressions. Even something like p.c
+		// has to be hoisted into a temporary, so that it cannot be
+		// reordered after the channel evaluation for a different
+		// case (if p were nil, then the timing of the fault would
+		// give this away).
 		t = marktemp(order);
 		for(l=n->list; l; l=l->next) {
 			if(l->n->op != OXCASE)
@@ -810,6 +819,8 @@ orderstmt(Node *n, Order *order)
 					// r->left == N means 'case <-c'.
 					// c is always evaluated; x and ok are only evaluated when assigned.
 					orderexpr(&r->right->left, order);
+					if(r->right->left->op != ONAME)
+						r->right->left = ordercopyexpr(r->right->left, r->right->left->type, order, 0);
 
 					// Introduce temporary for receive and move actual copy into case body.
 					// avoids problems with target being addressed, as usual.
@@ -1055,6 +1066,19 @@ orderexpr(Node **np, Order *order)
 		orderexpr(&n->left, order);
 		n = ordercopyexpr(n, n->type, order, 1);
 		break;
+
+	case OEQ:
+	case ONE:
+		orderexpr(&n->left, order);
+		orderexpr(&n->right, order);
+		t = n->left->type;
+		if(t->etype == TSTRUCT || isfixedarray(t)) {
+			// for complex comparisons, we need both args to be
+			// addressable so we can pass them to the runtime.
+			orderaddrtemp(&n->left, order);
+			orderaddrtemp(&n->right, order);
+		}
+		break;
 	}
 	
 	lineno = lno;
diff --git a/src/cmd/gc/plive.c b/src/cmd/gc/plive.c
index 716cdd108..dc4edad63 100644
--- a/src/cmd/gc/plive.c
+++ b/src/cmd/gc/plive.c
@@ -1113,8 +1113,7 @@ twobitwalktype1(Type *t, vlong *xoffset, Bvec *bv)
 		// struct { byte *str; intgo len; }
 		if((*xoffset & (widthptr-1)) != 0)
 			fatal("twobitwalktype1: invalid alignment, %T", t);
-		bvset(bv, (*xoffset / widthptr) * BitsPerPointer + 0);
-		bvset(bv, (*xoffset / widthptr) * BitsPerPointer + 1); // 3:0 = multiword:string
+		bvset(bv, (*xoffset / widthptr) * BitsPerPointer + 1); // 2 = live ptr in first slot
 		*xoffset += t->width;
 		break;
 
@@ -1145,9 +1144,7 @@ twobitwalktype1(Type *t, vlong *xoffset, Bvec *bv)
 			// struct { byte *array; uintgo len; uintgo cap; }
 			if((*xoffset & (widthptr-1)) != 0)
 				fatal("twobitwalktype1: invalid TARRAY alignment, %T", t);
-			bvset(bv, (*xoffset / widthptr) * BitsPerPointer + 0);
-			bvset(bv, (*xoffset / widthptr) * BitsPerPointer + 1);
-			bvset(bv, (*xoffset / widthptr) * BitsPerPointer + 2); // 3:1 = multiword/slice
+			bvset(bv, (*xoffset / widthptr) * BitsPerPointer + 1); // 2 = live ptr in first slot
 			*xoffset += t->width;
 		} else
 			for(i = 0; i < t->bound; i++)
diff --git a/src/cmd/gc/popt.c b/src/cmd/gc/popt.c
index 4c75e6c26..6e6db88ef 100644
--- a/src/cmd/gc/popt.c
+++ b/src/cmd/gc/popt.c
@@ -49,7 +49,7 @@ noreturn(Prog *p)
 		symlist[0] = pkglookup("panicindex", runtimepkg);
 		symlist[1] = pkglookup("panicslice", runtimepkg);
 		symlist[2] = pkglookup("throwinit", runtimepkg);
-		symlist[3] = pkglookup("panic", runtimepkg);
+		symlist[3] = pkglookup("gopanic", runtimepkg);
 		symlist[4] = pkglookup("panicwrap", runtimepkg);
 		symlist[5] = pkglookup("throwreturn", runtimepkg);
 		symlist[6] = pkglookup("selectgo", runtimepkg);
diff --git a/src/cmd/gc/racewalk.c b/src/cmd/gc/racewalk.c
index 285bd78a2..27581702c 100644
--- a/src/cmd/gc/racewalk.c
+++ b/src/cmd/gc/racewalk.c
@@ -419,8 +419,10 @@ racewalknode(Node **np, NodeList **init, int wr, int skip)
 ret:
 	if(n->op != OBLOCK)  // OBLOCK is handled above in a special way.
 		racewalklist(n->list, init);
-	racewalknode(&n->ntest, &n->ntest->ninit, 0, 0);
-	racewalknode(&n->nincr, &n->nincr->ninit, 0, 0);
+	if(n->ntest != N)
+		racewalknode(&n->ntest, &n->ntest->ninit, 0, 0);
+	if(n->nincr != N)
+		racewalknode(&n->nincr, &n->nincr->ninit, 0, 0);
 	racewalklist(n->nbody, nil);
 	racewalklist(n->nelse, nil);
 	racewalklist(n->rlist, nil);
diff --git a/src/cmd/gc/reflect.c b/src/cmd/gc/reflect.c
index 8170c15b6..f227054ca 100644
--- a/src/cmd/gc/reflect.c
+++ b/src/cmd/gc/reflect.c
@@ -378,7 +378,7 @@ methods(Type *t)
 
 	// type stored in interface word
 	it = t;
-	if(it->width > widthptr)
+	if(!isdirectiface(it))
 		it = ptrto(t);
 
 	// make list of methods for t,
@@ -724,7 +724,7 @@ dcommontype(Sym *s, int ot, Type *t)
 	if(ot != 0)
 		fatal("dcommontype %d", ot);
 
-	sizeofAlg = 4*widthptr;
+	sizeofAlg = 2*widthptr;
 	if(algarray == nil)
 		algarray = pkglookup("algarray", runtimepkg);
 	alg = algtype(t);
@@ -785,6 +785,8 @@ dcommontype(Sym *s, int ot, Type *t)
 		i = KindSlice;
 	if(!haspointers(t))
 		i |= KindNoPointers;
+	if(isdirectiface(t))
+		i |= KindDirectIface;
 	if(gcprog)
 		i |= KindGCProg;
 	ot = duint8(s, ot, i);  // kind
@@ -1239,8 +1241,7 @@ static Sym*
 dalgsym(Type *t)
 {
 	int ot;
-	Sym *s, *hash, *hashfunc, *eq;
-	char buf[100];
+	Sym *s, *hash, *hashfunc, *eq, *eqfunc;
 
 	// dalgsym is only called for a type that needs an algorithm table,
 	// which implies that the type is comparable (or else it would use ANOEQ).
@@ -1251,29 +1252,18 @@ dalgsym(Type *t)
 	eq = typesymprefix(".eq", t);
 	geneq(eq, t);
 
-	// make Go func (a closure) for calling the hash function from Go
+	// make Go funcs (closures) for calling hash and equal from Go
 	hashfunc = typesymprefix(".hashfunc", t);
 	dsymptr(hashfunc, 0, hash, 0);
 	ggloblsym(hashfunc, widthptr, DUPOK|RODATA);
+	eqfunc = typesymprefix(".eqfunc", t);
+	dsymptr(eqfunc, 0, eq, 0);
+	ggloblsym(eqfunc, widthptr, DUPOK|RODATA);
 
-	// ../../pkg/runtime/runtime.h:/Alg
+	// ../../pkg/runtime/alg.go:/typeAlg
 	ot = 0;
 	ot = dsymptr(s, ot, hashfunc, 0);
-	ot = dsymptr(s, ot, eq, 0);
-	ot = dsymptr(s, ot, pkglookup("memprint", runtimepkg), 0);
-	switch(t->width) {
-	default:
-		ot = dsymptr(s, ot, pkglookup("memcopy", runtimepkg), 0);
-		break;
-	case 1:
-	case 2:
-	case 4:
-	case 8:
-	case 16:
-		snprint(buf, sizeof buf, "memcopy%d", (int)t->width*8);
-		ot = dsymptr(s, ot, pkglookup(buf, runtimepkg), 0);
-		break;
-	}
+	ot = dsymptr(s, ot, eqfunc, 0);
 
 	ggloblsym(s, ot, DUPOK|RODATA);
 	return s;
@@ -1511,8 +1501,8 @@ gengcprog1(ProgGen *g, Type *t, vlong *xoffset)
 		*xoffset += t->width;
 		break;
 	case TSTRING:
-		proggendata(g, BitsMultiWord);
-		proggendata(g, BitsString);
+		proggendata(g, BitsPointer);
+		proggendata(g, BitsScalar);
 		*xoffset += t->width;
 		break;
 	case TINTER:
@@ -1525,8 +1515,8 @@ gengcprog1(ProgGen *g, Type *t, vlong *xoffset)
 		break;
 	case TARRAY:
 		if(isslice(t)) {
-			proggendata(g, BitsMultiWord);
-			proggendata(g, BitsSlice);
+			proggendata(g, BitsPointer);
+			proggendata(g, BitsScalar);
 			proggendata(g, BitsScalar);
 		} else {
 			t1 = t->type;
diff --git a/src/cmd/gc/runtime.go b/src/cmd/gc/runtime.go
index 0257c3c7d..128fd1a31 100644
--- a/src/cmd/gc/runtime.go
+++ b/src/cmd/gc/runtime.go
@@ -20,12 +20,13 @@ func throwreturn()
 func throwinit()
 func panicwrap(string, string, string)
 
-func panic(interface{})
-func recover(*int32) interface{}
+func gopanic(interface{})
+func gorecover(*int32) interface{}
 
 func printbool(bool)
 func printfloat(float64)
 func printint(int64)
+func printhex(uint64)
 func printuint(uint64)
 func printcomplex(complex128)
 func printstring(string)
@@ -84,8 +85,6 @@ func efaceeq(i1 any, i2 any) (ret bool)
 func ifacethash(i1 any) (ret uint32)
 func efacethash(i1 any) (ret uint32)
 
-func equal(typ *byte, x1, x2 any) (ret bool)
-
 // *byte is really *runtime.Type
 func makemap(mapType *byte, hint int64) (hmap map[any]any)
 func mapaccess1(mapType *byte, hmap map[any]any, key *any) (val *any)
@@ -124,12 +123,12 @@ func makeslice(typ *byte, nel int64, cap int64) (ary []any)
 func growslice(typ *byte, old []any, n int64) (ary []any)
 func memmove(to *any, frm *any, length uintptr)
 
-func memequal(eq *bool, size uintptr, x, y *any)
-func memequal8(eq *bool, size uintptr, x, y *any)
-func memequal16(eq *bool, size uintptr, x, y *any)
-func memequal32(eq *bool, size uintptr, x, y *any)
-func memequal64(eq *bool, size uintptr, x, y *any)
-func memequal128(eq *bool, size uintptr, x, y *any)
+func memequal(x, y *any, size uintptr) bool
+func memequal8(x, y *any, size uintptr) bool
+func memequal16(x, y *any, size uintptr) bool
+func memequal32(x, y *any, size uintptr) bool
+func memequal64(x, y *any, size uintptr) bool
+func memequal128(x, y *any, size uintptr) bool
 
 // only used on 32-bit
 func int64div(int64, int64) int64
diff --git a/src/cmd/gc/select.c b/src/cmd/gc/select.c
index 7168e6b80..ed23e4318 100644
--- a/src/cmd/gc/select.c
+++ b/src/cmd/gc/select.c
@@ -337,19 +337,23 @@ selecttype(int32 size)
 	sudog->list = list(sudog->list, nod(ODCLFIELD, newname(lookup("g")), typenod(ptrto(types[TUINT8]))));
 	sudog->list = list(sudog->list, nod(ODCLFIELD, newname(lookup("selectdone")), typenod(ptrto(types[TUINT8]))));
 	sudog->list = list(sudog->list, nod(ODCLFIELD, newname(lookup("link")), typenod(ptrto(types[TUINT8]))));
+	sudog->list = list(sudog->list, nod(ODCLFIELD, newname(lookup("prev")), typenod(ptrto(types[TUINT8]))));
 	sudog->list = list(sudog->list, nod(ODCLFIELD, newname(lookup("elem")), typenod(ptrto(types[TUINT8]))));
 	sudog->list = list(sudog->list, nod(ODCLFIELD, newname(lookup("releasetime")), typenod(types[TUINT64])));
+	sudog->list = list(sudog->list, nod(ODCLFIELD, newname(lookup("nrelease")), typenod(types[TINT32])));
+	sudog->list = list(sudog->list, nod(ODCLFIELD, newname(lookup("waitlink")), typenod(ptrto(types[TUINT8]))));
 	typecheck(&sudog, Etype);
 	sudog->type->noalg = 1;
 	sudog->type->local = 1;
 
 	scase = nod(OTSTRUCT, N, N);
-	scase->list = list(scase->list, nod(ODCLFIELD, newname(lookup("sg")), sudog));
+	scase->list = list(scase->list, nod(ODCLFIELD, newname(lookup("elem")), typenod(ptrto(types[TUINT8]))));
 	scase->list = list(scase->list, nod(ODCLFIELD, newname(lookup("chan")), typenod(ptrto(types[TUINT8]))));
 	scase->list = list(scase->list, nod(ODCLFIELD, newname(lookup("pc")), typenod(types[TUINTPTR])));
 	scase->list = list(scase->list, nod(ODCLFIELD, newname(lookup("kind")), typenod(types[TUINT16])));
 	scase->list = list(scase->list, nod(ODCLFIELD, newname(lookup("so")), typenod(types[TUINT16])));
 	scase->list = list(scase->list, nod(ODCLFIELD, newname(lookup("receivedp")), typenod(ptrto(types[TUINT8]))));
+	scase->list = list(scase->list, nod(ODCLFIELD, newname(lookup("releasetime")), typenod(types[TUINT64])));
 	typecheck(&scase, Etype);
 	scase->type->noalg = 1;
 	scase->type->local = 1;
diff --git a/src/cmd/gc/subr.c b/src/cmd/gc/subr.c
index 0195f3d62..d62d55e77 100644
--- a/src/cmd/gc/subr.c
+++ b/src/cmd/gc/subr.c
@@ -656,11 +656,15 @@ maptype(Type *key, Type *val)
 {
 	Type *t;
 	Type *bad;
-	int atype;
+	int atype, mtype;
 
 	if(key != nil) {
 		atype = algtype1(key, &bad);
-		switch(bad == T ? key->etype : bad->etype) {
+		if(bad == T)
+			mtype = key->etype;
+		else
+			mtype = bad->etype;
+		switch(mtype) {
 		default:
 			if(atype == ANOEQ)
 				yyerror("invalid map key type %T", key);
@@ -2856,18 +2860,19 @@ genhash(Sym *sym, Type *t)
 }
 
 // Return node for
-//	if p.field != q.field { *eq = false; return }
+//	if p.field != q.field { return false }
 static Node*
-eqfield(Node *p, Node *q, Node *field, Node *eq)
+eqfield(Node *p, Node *q, Node *field)
 {
-	Node *nif, *nx, *ny;
+	Node *nif, *nx, *ny, *r;
 
 	nx = nod(OXDOT, p, field);
 	ny = nod(OXDOT, q, field);
 	nif = nod(OIF, N, N);
 	nif->ntest = nod(ONE, nx, ny);
-	nif->nbody = list(nif->nbody, nod(OAS, nod(OIND, eq, N), nodbool(0)));
-	nif->nbody = list(nif->nbody, nod(ORETURN, N, N));
+	r = nod(ORETURN, N, N);
+	r->list = list(r->list, nodbool(0));
+	nif->nbody = list(nif->nbody, r);
 	return nif;
 }
 
@@ -2896,11 +2901,11 @@ eqmemfunc(vlong size, Type *type)
 }
 
 // Return node for
-//	if memequal(size, &p.field, &q.field, eq); !*eq { return }
+//	if !memequal(&p.field, &q.field, size) { return false }
 static Node*
-eqmem(Node *p, Node *q, Node *field, vlong size, Node *eq)
+eqmem(Node *p, Node *q, Node *field, vlong size)
 {
-	Node *nif, *nx, *ny, *call;
+	Node *nif, *nx, *ny, *call, *r;
 
 	nx = nod(OADDR, nod(OXDOT, p, field), N);
 	nx->etype = 1;  // does not escape
@@ -2910,15 +2915,16 @@ eqmem(Node *p, Node *q, Node *field, vlong size, Node *eq)
 	typecheck(&ny, Erv);
 
 	call = nod(OCALL, eqmemfunc(size, nx->type->type), N);
-	call->list = list(call->list, eq);
-	call->list = list(call->list, nodintconst(size));
 	call->list = list(call->list, nx);
 	call->list = list(call->list, ny);
+	call->list = list(call->list, nodintconst(size));
 
 	nif = nod(OIF, N, N);
 	nif->ninit = list(nif->ninit, call);
-	nif->ntest = nod(ONOT, nod(OIND, eq, N), N);
-	nif->nbody = list(nif->nbody, nod(ORETURN, N, N));
+	nif->ntest = nod(ONOT, call, N);
+	r = nod(ORETURN, N, N);
+	r->list = list(r->list, nodbool(0));
+	nif->nbody = list(nif->nbody, r);
 	return nif;
 }
 
@@ -2928,7 +2934,7 @@ eqmem(Node *p, Node *q, Node *field, vlong size, Node *eq)
 void
 geneq(Sym *sym, Type *t)
 {
-	Node *n, *fn, *np, *neq, *nq, *tfn, *nif, *ni, *nx, *ny, *nrange;
+	Node *n, *fn, *np, *nq, *tfn, *nif, *ni, *nx, *ny, *nrange, *r;
 	Type *t1, *first;
 	int old_safemode;
 	int64 size;
@@ -2941,24 +2947,23 @@ geneq(Sym *sym, Type *t)
 	dclcontext = PEXTERN;
 	markdcl();
 
-	// func sym(eq *bool, s uintptr, p, q *T)
+	// func sym(p, q *T, s uintptr) bool
 	fn = nod(ODCLFUNC, N, N);
 	fn->nname = newname(sym);
 	fn->nname->class = PFUNC;
 	tfn = nod(OTFUNC, N, N);
 	fn->nname->ntype = tfn;
 
-	n = nod(ODCLFIELD, newname(lookup("eq")), typenod(ptrto(types[TBOOL])));
-	tfn->list = list(tfn->list, n);
-	neq = n->left;
-	n = nod(ODCLFIELD, newname(lookup("s")), typenod(types[TUINTPTR]));
-	tfn->list = list(tfn->list, n);
 	n = nod(ODCLFIELD, newname(lookup("p")), typenod(ptrto(t)));
 	tfn->list = list(tfn->list, n);
 	np = n->left;
 	n = nod(ODCLFIELD, newname(lookup("q")), typenod(ptrto(t)));
 	tfn->list = list(tfn->list, n);
 	nq = n->left;
+	n = nod(ODCLFIELD, newname(lookup("s")), typenod(types[TUINTPTR]));
+	tfn->list = list(tfn->list, n);
+	n = nod(ODCLFIELD, N, typenod(types[TBOOL]));
+	tfn->rlist = list(tfn->rlist, n);
 
 	funchdr(fn);
 
@@ -2984,7 +2989,7 @@ geneq(Sym *sym, Type *t)
 		colasdefn(nrange->list, nrange);
 		ni = nrange->list->n;
 		
-		// if p[i] != q[i] { *eq = false; return }
+		// if p[i] != q[i] { return false }
 		nx = nod(OINDEX, np, ni);
 		nx->bounded = 1;
 		ny = nod(OINDEX, nq, ni);
@@ -2992,13 +2997,11 @@ geneq(Sym *sym, Type *t)
 
 		nif = nod(OIF, N, N);
 		nif->ntest = nod(ONE, nx, ny);
-		nif->nbody = list(nif->nbody, nod(OAS, nod(OIND, neq, N), nodbool(0)));
-		nif->nbody = list(nif->nbody, nod(ORETURN, N, N));
+		r = nod(ORETURN, N, N);
+		r->list = list(r->list, nodbool(0));
+		nif->nbody = list(nif->nbody, r);
 		nrange->nbody = list(nrange->nbody, nif);
 		fn->nbody = list(fn->nbody, nrange);
-
-		// *eq = true;
-		fn->nbody = list(fn->nbody, nod(OAS, nod(OIND, neq, N), nodbool(1)));
 		break;
 
 	case TSTRUCT:
@@ -3023,16 +3026,16 @@ geneq(Sym *sym, Type *t)
 			// cross-package unexported fields.
 			if(first != T) {
 				if(first->down == t1) {
-					fn->nbody = list(fn->nbody, eqfield(np, nq, newname(first->sym), neq));
+					fn->nbody = list(fn->nbody, eqfield(np, nq, newname(first->sym)));
 				} else if(first->down->down == t1) {
-					fn->nbody = list(fn->nbody, eqfield(np, nq, newname(first->sym), neq));
+					fn->nbody = list(fn->nbody, eqfield(np, nq, newname(first->sym)));
 					first = first->down;
 					if(!isblanksym(first->sym))
-						fn->nbody = list(fn->nbody, eqfield(np, nq, newname(first->sym), neq));
+						fn->nbody = list(fn->nbody, eqfield(np, nq, newname(first->sym)));
 				} else {
 					// More than two fields: use memequal.
 					size = offend - first->width; // first->width is offset
-					fn->nbody = list(fn->nbody, eqmem(np, nq, newname(first->sym), size, neq));
+					fn->nbody = list(fn->nbody, eqmem(np, nq, newname(first->sym), size));
 				}
 				first = T;
 			}
@@ -3042,14 +3045,17 @@ geneq(Sym *sym, Type *t)
 				continue;
 
 			// Check this field, which is not just memory.
-			fn->nbody = list(fn->nbody, eqfield(np, nq, newname(t1->sym), neq));
+			fn->nbody = list(fn->nbody, eqfield(np, nq, newname(t1->sym)));
 		}
 
-		// *eq = true;
-		fn->nbody = list(fn->nbody, nod(OAS, nod(OIND, neq, N), nodbool(1)));
 		break;
 	}
 
+	// return true
+	r = nod(ORETURN, N, N);
+	r->list = list(r->list, nodbool(1));
+	fn->nbody = list(fn->nbody, r);
+
 	if(debug['r'])
 		dumplist("geneq body", fn->nbody);
 
@@ -3792,3 +3798,42 @@ checknil(Node *x, NodeList **init)
 	n->typecheck = 1;
 	*init = list(*init, n);
 }
+
+/*
+ * Can this type be stored directly in an interface word?
+ */
+int
+isdirectiface(Type *t)
+{
+	// Setting IfacePointerOnly = 1 changes the
+	// interface representation so that the data word
+	// in an interface value must always be a pointer.
+	// Setting it to 0 uses the original representation,
+	// where the data word can hold a pointer or any
+	// non-pointer value no bigger than a pointer.
+	enum {
+		IfacePointerOnly = 1,
+	};
+
+	if(IfacePointerOnly) {
+		switch(t->etype) {
+		case TPTR32:
+		case TPTR64:
+		case TCHAN:
+		case TMAP:
+		case TFUNC:
+		case TUNSAFEPTR:
+			return 1;
+		case TARRAY:
+			// Array of 1 direct iface type can be direct.
+			return t->bound == 1 && isdirectiface(t->type);
+		case TSTRUCT:
+			// Struct with 1 field of direct iface type can be direct.
+			return t->type != T && t->type->down == T && isdirectiface(t->type->type);
+		}
+		return 0;
+	}
+	
+	dowidth(t);
+	return t->width <= widthptr;
+}
diff --git a/src/cmd/gc/typecheck.c b/src/cmd/gc/typecheck.c
index 92e9ad521..746feb4d1 100644
--- a/src/cmd/gc/typecheck.c
+++ b/src/cmd/gc/typecheck.c
@@ -525,19 +525,6 @@ reswitch:
 		op = n->etype;
 		goto arith;
 
-	case OADDPTR:
-		ok |= Erv;
-		l = typecheck(&n->left, Erv);
-		r = typecheck(&n->right, Erv);
-		if(l->type == T || r->type == T)
-			goto error;
-		if(l->type->etype != tptr)
-			fatal("bad OADDPTR left type %E for %N", l->type->etype, n->left);
-		if(r->type->etype != TUINTPTR)
-			fatal("bad OADDPTR right type %E for %N", r->type->etype, n->right);
-		n->type = types[tptr];
-		goto ret;
-
 	case OADD:
 	case OAND:
 	case OANDAND:
@@ -2965,7 +2952,7 @@ typecheckas2(Node *n)
 			if(l->defn == n)
 				l->type = r->type;
 			l = n->list->next->n;
-			if(l->type != T)
+			if(l->type != T && l->type->etype != TBOOL)
 				checkassignto(types[TBOOL], l);
 			if(l->defn == n && l->ntype == N)
 				l->type = types[TBOOL];
diff --git a/src/cmd/gc/walk.c b/src/cmd/gc/walk.c
index cf25a3eac..365ece267 100644
--- a/src/cmd/gc/walk.c
+++ b/src/cmd/gc/walk.c
@@ -543,11 +543,11 @@ walkexpr(Node **np, NodeList **init)
 		goto ret;
 
 	case OPANIC:
-		n = mkcall("panic", T, init, n->left);
+		n = mkcall("gopanic", T, init, n->left);
 		goto ret;
 
 	case ORECOVER:
-		n = mkcall("recover", n->type, init, nod(OADDR, nodfp, N));
+		n = mkcall("gorecover", n->type, init, nod(OADDR, nodfp, N));
 		goto ret;
 
 	case OLITERAL:
@@ -673,7 +673,7 @@ walkexpr(Node **np, NodeList **init)
 			n1 = nod(OADDR, n->list->n, N);
 		n1->etype = 1; // addr does not escape
 		fn = chanfn("chanrecv2", 2, r->left->type);
-		r = mkcall1(fn, types[TBOOL], init, typename(r->left->type), r->left, n1);
+		r = mkcall1(fn, n->list->next->n->type, init, typename(r->left->type), r->left, n1);
 		n = nod(OAS, n->list->next->n, r);
 		typecheck(&n, Etop);
 		goto ret;
@@ -723,6 +723,12 @@ walkexpr(Node **np, NodeList **init)
 		var->typecheck = 1;
 		fn = mapfn(p, t);
 		r = mkcall1(fn, getoutargx(fn->type), init, typename(t), r->left, key);
+
+		// mapaccess2* returns a typed bool, but due to spec changes,
+		// the boolean result of i.(T) is now untyped so we make it the
+		// same type as the variable on the lhs.
+		if(!isblank(n->list->next->n))
+			r->type->type->down->type = n->list->next->n->type;
 		n->rlist = list1(r);
 		n->op = OAS2FUNC;
 		n->list->n = var;
@@ -770,6 +776,12 @@ walkexpr(Node **np, NodeList **init)
 			*p = '\0';
 			
 			fn = syslook(buf, 1);
+
+			// runtime.assert(E|I)2TOK returns a typed bool, but due
+			// to spec changes, the boolean result of i.(T) is now untyped
+			// so we make it the same type as the variable on the lhs.
+			if(!isblank(n->list->next->n))
+				fn->type->type->down->type->type = n->list->next->n->type;
 			ll = list1(typename(r->type));
 			ll = list(ll, r->left);
 			argtype(fn, r->left->type);
@@ -822,9 +834,7 @@ walkexpr(Node **np, NodeList **init)
 		walkexpr(&n->left, init);
 
 		// Optimize convT2E as a two-word copy when T is uintptr-shaped.
-		if(!isinter(n->left->type) && isnilinter(n->type) &&
-		   (n->left->type->width == widthptr) &&
-		   isint[simsimtype(n->left->type)]) {
+		if(isnilinter(n->type) && isdirectiface(n->left->type) && n->left->type->width == widthptr && isint[simsimtype(n->left->type)]) {
 			l = nod(OEFACE, typename(n->left->type), n->left);
 			l->type = n->type;
 			l->typecheck = n->typecheck;
@@ -872,8 +882,7 @@ walkexpr(Node **np, NodeList **init)
 			l->addable = 1;
 			ll = list(ll, l);
 
-			if(n->left->type->width == widthptr &&
-		   	   isint[simsimtype(n->left->type)]) {
+			if(isdirectiface(n->left->type) && n->left->type->width == widthptr && isint[simsimtype(n->left->type)]) {
 				/* For pointer types, we can make a special form of optimization
 				 *
 				 * These statements are put onto the expression init list:
@@ -1828,9 +1837,12 @@ walkprint(Node *nn, NodeList **init, int defer)
 					t = types[TINT64];
 				}
 			} else {
-				if(et == TUINT64)
-					on = syslook("printuint", 0);
-				else
+				if(et == TUINT64) {
+					if((t->sym->pkg == runtimepkg || compiling_runtime) && strcmp(t->sym->name, "hex") == 0)
+						on = syslook("printhex", 0);
+					else
+						on = syslook("printuint", 0);
+				} else
 					on = syslook("printint", 0);
 			}
 		} else if(isfloat[et]) {
@@ -2866,14 +2878,14 @@ sliceany(Node* n, NodeList **init)
 			lb = N;
 	}
 
-	// dynamic checks convert all bounds to unsigned to save us the bound < 0 comparison
-	// generate
-	//     if hb > bound || lb > hb { panicslice() }
+	// Checking src[lb:hb:cb] or src[lb:hb].
+	// if chk0 || chk1 || chk2 { panicslice() }
 	chk = N;
-	chk0 = N;
-	chk1 = N;
-	chk2 = N;
+	chk0 = N; // cap(src) < cb
+	chk1 = N; // cb < hb for src[lb:hb:cb]; cap(src) < hb for src[lb:hb]
+	chk2 = N; // hb < lb
 
+	// All comparisons are unsigned to avoid testing < 0.
 	bt = types[simtype[TUINT]];
 	if(cb != N && cb->type->width > 4)
 		bt = types[TUINT64];
@@ -3013,10 +3025,10 @@ eqfor(Type *t)
 	n = newname(sym);
 	n->class = PFUNC;
 	ntype = nod(OTFUNC, N, N);
-	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(ptrto(types[TBOOL]))));
-	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(types[TUINTPTR])));
 	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(ptrto(t))));
 	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(ptrto(t))));
+	ntype->list = list(ntype->list, nod(ODCLFIELD, N, typenod(types[TUINTPTR])));
+	ntype->rlist = list(ntype->rlist, nod(ODCLFIELD, N, typenod(types[TBOOL])));
 	typecheck(&ntype, Etype);
 	n->type = ntype->type;
 	return n;
@@ -3037,10 +3049,9 @@ countfield(Type *t)
 static void
 walkcompare(Node **np, NodeList **init)
 {
-	Node *n, *l, *r, *fn, *call, *a, *li, *ri, *expr;
+	Node *n, *l, *r, *call, *a, *li, *ri, *expr;
 	int andor, i;
 	Type *t, *t1;
-	static Node *tempbool;
 	
 	n = *np;
 	
@@ -3058,8 +3069,9 @@ walkcompare(Node **np, NodeList **init)
 		break;
 	}
 	
-	if(!islvalue(n->left) || !islvalue(n->right))
-		goto hard;
+	if(!islvalue(n->left) || !islvalue(n->right)) {
+		fatal("arguments of comparison must be lvalues");
+	}
 
 	l = temp(ptrto(t));
 	a = nod(OAS, l, nod(OADDR, n->left, N));
@@ -3118,57 +3130,16 @@ walkcompare(Node **np, NodeList **init)
 		goto ret;
 	}
 
-	// Chose not to inline, but still have addresses.
-	// Call equality function directly.
-	// The equality function requires a bool pointer for
-	// storing its address, because it has to be callable
-	// from C, and C can't access an ordinary Go return value.
-	// To avoid creating many temporaries, cache one per function.
-	if(tempbool == N || tempbool->curfn != curfn)
-		tempbool = temp(types[TBOOL]);
-	
+	// Chose not to inline.  Call equality function directly.
 	call = nod(OCALL, eqfor(t), N);
-	a = nod(OADDR, tempbool, N);
-	a->etype = 1;  // does not escape
-	call->list = list(call->list, a);
-	call->list = list(call->list, nodintconst(t->width));
 	call->list = list(call->list, l);
 	call->list = list(call->list, r);
-	typecheck(&call, Etop);
-	walkstmt(&call);
-	*init = list(*init, call);
-
-	// tempbool cannot be used directly as multiple comparison
-	// expressions may exist in the same statement. Create another
-	// temporary to hold the value (its address is not taken so it can
-	// be optimized away).
-	r = temp(types[TBOOL]);
-	a = nod(OAS, r, tempbool);
-	typecheck(&a, Etop);
-	walkstmt(&a);
-	*init = list(*init, a);
-
+	call->list = list(call->list, nodintconst(t->width));
+	r = call;
 	if(n->op != OEQ)
 		r = nod(ONOT, r, N);
 	goto ret;
 
-hard:
-	// Cannot take address of one or both of the operands.
-	// Instead, pass directly to runtime helper function.
-	// Easier on the stack than passing the address
-	// of temporary variables, because we are better at reusing
-	// the argument space than temporary variable space.
-	fn = syslook("equal", 1);
-	l = n->left;
-	r = n->right;
-	argtype(fn, n->left->type);
-	argtype(fn, n->left->type);
-	r = mkcall1(fn, n->type, init, typename(n->left->type), l, r);
-	if(n->op == ONE) {
-		r = nod(ONOT, r, N);
-	}
-	goto ret;
-
 ret:
 	typecheck(&r, Erv);
 	walkexpr(&r, init);
diff --git a/src/cmd/go/build.go b/src/cmd/go/build.go
index fa9262c0f..fd92ca278 100644
--- a/src/cmd/go/build.go
+++ b/src/cmd/go/build.go
@@ -885,7 +885,7 @@ func (b *builder) build(a *action) (err error) {
 	}
 
 	if len(gofiles) == 0 {
-		return &build.NoGoError{a.p.Dir}
+		return &build.NoGoError{Dir: a.p.Dir}
 	}
 
 	// If we're doing coverage, preprocess the .go files and put them in the work directory
@@ -1613,8 +1613,10 @@ func (gcToolchain) gc(b *builder, p *Package, archive, obj string, importArgs []
 }
 
 func (gcToolchain) asm(b *builder, p *Package, obj, ofile, sfile string) error {
+	// Add -I pkg/GOOS_GOARCH so #include "textflag.h" works in .s files.
+	inc := filepath.Join(goroot, "pkg", fmt.Sprintf("%s_%s", goos, goarch))
 	sfile = mkAbs(p.Dir, sfile)
-	return b.run(p.Dir, p.ImportPath, nil, tool(archChar+"a"), "-trimpath", b.work, "-I", obj, "-o", ofile, "-D", "GOOS_"+goos, "-D", "GOARCH_"+goarch, sfile)
+	return b.run(p.Dir, p.ImportPath, nil, tool(archChar+"a"), "-trimpath", b.work, "-I", obj, "-I", inc, "-o", ofile, "-D", "GOOS_"+goos, "-D", "GOARCH_"+goarch, sfile)
 }
 
 func (gcToolchain) pkgpath(basedir string, p *Package) string {
@@ -2312,7 +2314,23 @@ func (b *builder) cgo(p *Package, cgoExe, obj string, gccfiles, gxxfiles, mfiles
 			nonGccObjs = append(nonGccObjs, f)
 		}
 	}
-	if err := b.gccld(p, ofile, stringList(bareLDFLAGS, "-Wl,-r", "-nostdlib", staticLibs), gccObjs); err != nil {
+	ldflags := stringList(bareLDFLAGS, "-Wl,-r", "-nostdlib", staticLibs)
+
+	// Some systems, such as Ubuntu, always add --build-id to
+	// every link, but we don't want a build ID since we are
+	// producing an object file.  On some of those system a plain
+	// -r (not -Wl,-r) will turn off --build-id, but clang 3.0
+	// doesn't support a plain -r.  I don't know how to turn off
+	// --build-id when using clang other than passing a trailing
+	// --build-id=none.  So that is what we do, but only on
+	// systems likely to support it, which is to say, systems that
+	// normally use gold or the GNU linker.
+	switch goos {
+	case "android", "dragonfly", "linux", "netbsd":
+		ldflags = append(ldflags, "-Wl,--build-id=none")
+	}
+
+	if err := b.gccld(p, ofile, ldflags, gccObjs); err != nil {
 		return nil, nil, err
 	}
 
diff --git a/src/cmd/go/doc.go b/src/cmd/go/doc.go
index 4778048b5..0d4e26389 100644
--- a/src/cmd/go/doc.go
+++ b/src/cmd/go/doc.go
@@ -19,6 +19,7 @@ The commands are:
     env         print Go environment information
     fix         run go tool fix on packages
     fmt         run gofmt on package sources
+    generate    generate Go files by processing source
     get         download and install packages and dependencies
     install     compile and install packages and dependencies
     list        list packages
@@ -219,6 +220,98 @@ To run gofmt with specific options, run gofmt itself.
 See also: go fix, go vet.
 
 
+Generate Go files by processing source
+
+Usage:
+
+	go generate [-run regexp] [file.go... | packages]
+
+Generate runs commands described by directives within existing
+files. Those commands can run any process but the intent is to
+create or update Go source files, for instance by running yacc.
+
+Go generate is never run automatically by go build, go get, go test,
+and so on. It must be run explicitly.
+
+Directives are written as a whole-line comment of the form
+
+	//go:generate command argument...
+
+(note: no space in "//go") where command is the generator to be
+run, corresponding to an executable file that can be run locally.
+It must either be in the shell path (gofmt), a fully qualified path
+(/usr/you/bin/mytool), or a command alias, described below.
+
+The arguments are space-separated tokens or double-quoted strings
+passed to the generator as individual arguments when it is run.
+
+Quoted strings use Go syntax and are evaluated before execution; a
+quoted string appears a single argument to the generator.
+
+Go generate sets several variables when it runs the generator:
+
+	$GOARCH
+		The execution architecture (arm, amd64, etc.)
+	$GOOS
+		The execution operating system (linux, windows, etc.)
+	$GOFILE
+		The base name of the file.
+	$GOPACKAGE
+		The name of the package of the file containing the directive.
+
+Other than variable substition and quoted-string evaluation, no
+special processing such as "globbing" is performed on the command
+line.
+
+As a last step before running the command, any invocations of any
+environment variables with alphanumeric names, such as $GOFILE or
+$HOME, are expanded throughout the command line. The syntax for
+variable expansion is $NAME on all operating systems.  Due to the
+order of evaluation, variables are expanded even inside quoted
+strings. If the variable NAME is not set, $NAME expands to the
+empty string.
+
+A directive of the form,
+
+	//go:generate -command xxx args...
+
+specifies, for the remainder of this source file only, that the
+string xxx represents the command identified by the arguments. This
+can be used to create aliases or to handle multiword generators.
+For example,
+
+	//go:generate -command yacc go tool yacc
+
+specifies that the command "yacc" represents the generator
+"go tool yacc".
+
+Generate processes packages in the order given on the command line,
+one at a time. If the command line lists .go files, they are treated
+as a single package. Within a package, generate processes the
+source files in a package in file name order, one at a time. Within
+a source file, generate runs generators in the order they appear
+in the file, one at a time.
+
+If any generator returns an error exit status, "go generate" skips
+all further processing for that package.
+
+The generator is run in the package's source directory.
+
+Go generate accepts one specific flag:
+
+	-run=""
+		if non-empty, specifies a regular expression to
+		select directives whose command matches the expression.
+
+It also accepts the standard build flags -v, -n, and -x.
+The -v flag prints the names of packages and files as they are
+processed.
+The -n flag prints commands that would be executed.
+The -x flag prints commands as they are executed.
+
+For more about specifying packages, see 'go help packages'.
+
+
 Download and install packages and dependencies
 
 Usage:
@@ -750,10 +843,10 @@ will result in the following request(s):
 
 If that page contains the meta tag
 
-	<meta name="go-import" content="example.org git https://code.example/r/p/exproj">
+	<meta name="go-import" content="example.org git https://code.org/r/p/exproj">
 
 the go tool will verify that https://example.org/?go-get=1 contains the
-same meta tag and then git clone https://code.example/r/p/exproj into
+same meta tag and then git clone https://code.org/r/p/exproj into
 GOPATH/src/example.org.
 
 New downloaded packages are written to the first directory
diff --git a/src/cmd/go/generate.go b/src/cmd/go/generate.go
new file mode 100644
index 000000000..167758207
--- /dev/null
+++ b/src/cmd/go/generate.go
@@ -0,0 +1,355 @@
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+var cmdGenerate = &Command{
+	Run:       runGenerate,
+	UsageLine: "generate [-run regexp] [file.go... | packages]",
+	Short:     "generate Go files by processing source",
+	Long: `
+Generate runs commands described by directives within existing
+files. Those commands can run any process but the intent is to
+create or update Go source files, for instance by running yacc.
+
+Go generate is never run automatically by go build, go get, go test,
+and so on. It must be run explicitly.
+
+Directives are written as a whole-line comment of the form
+
+	//go:generate command argument...
+
+(note: no space in "//go") where command is the generator to be
+run, corresponding to an executable file that can be run locally.
+It must either be in the shell path (gofmt), a fully qualified path
+(/usr/you/bin/mytool), or a command alias, described below.
+
+The arguments are space-separated tokens or double-quoted strings
+passed to the generator as individual arguments when it is run.
+
+Quoted strings use Go syntax and are evaluated before execution; a
+quoted string appears a single argument to the generator.
+
+Go generate sets several variables when it runs the generator:
+
+	$GOARCH
+		The execution architecture (arm, amd64, etc.)
+	$GOOS
+		The execution operating system (linux, windows, etc.)
+	$GOFILE
+		The base name of the file.
+	$GOPACKAGE
+		The name of the package of the file containing the directive.
+
+Other than variable substition and quoted-string evaluation, no
+special processing such as "globbing" is performed on the command
+line.
+
+As a last step before running the command, any invocations of any
+environment variables with alphanumeric names, such as $GOFILE or
+$HOME, are expanded throughout the command line. The syntax for
+variable expansion is $NAME on all operating systems.  Due to the
+order of evaluation, variables are expanded even inside quoted
+strings. If the variable NAME is not set, $NAME expands to the
+empty string.
+
+A directive of the form,
+
+	//go:generate -command xxx args...
+
+specifies, for the remainder of this source file only, that the
+string xxx represents the command identified by the arguments. This
+can be used to create aliases or to handle multiword generators.
+For example,
+
+	//go:generate -command yacc go tool yacc
+
+specifies that the command "yacc" represents the generator
+"go tool yacc".
+
+Generate processes packages in the order given on the command line,
+one at a time. If the command line lists .go files, they are treated
+as a single package. Within a package, generate processes the
+source files in a package in file name order, one at a time. Within
+a source file, generate runs generators in the order they appear
+in the file, one at a time.
+
+If any generator returns an error exit status, "go generate" skips
+all further processing for that package.
+
+The generator is run in the package's source directory.
+
+Go generate accepts one specific flag:
+
+	-run=""
+		if non-empty, specifies a regular expression to
+		select directives whose command matches the expression.
+
+It also accepts the standard build flags -v, -n, and -x.
+The -v flag prints the names of packages and files as they are
+processed.
+The -n flag prints commands that would be executed.
+The -x flag prints commands as they are executed.
+
+For more about specifying packages, see 'go help packages'.
+	`,
+}
+
+var generateRunFlag string // generate -run flag
+
+func init() {
+	addBuildFlags(cmdGenerate)
+	cmdGenerate.Flag.StringVar(&generateRunFlag, "run", "", "")
+}
+
+func runGenerate(cmd *Command, args []string) {
+	// Even if the arguments are .go files, this loop suffices.
+	for _, pkg := range packages(args) {
+		for _, file := range pkg.gofiles {
+			if !generate(pkg.Name, file) {
+				break
+			}
+		}
+	}
+}
+
+// generate runs the generation directives for a single file.
+func generate(pkg, absFile string) bool {
+	fd, err := os.Open(absFile)
+	if err != nil {
+		log.Fatalf("generate: %s", err)
+	}
+	defer fd.Close()
+	g := &Generator{
+		r:        fd,
+		path:     absFile,
+		pkg:      pkg,
+		commands: make(map[string][]string),
+	}
+	return g.run()
+}
+
+// A Generator represents the state of a single Go source file
+// being scanned for generator commands.
+type Generator struct {
+	r        io.Reader
+	path     string // full rooted path name.
+	dir      string // full rooted directory of file.
+	file     string // base name of file.
+	pkg      string
+	commands map[string][]string
+	lineNum  int
+}
+
+// run runs the generators in the current file.
+func (g *Generator) run() (ok bool) {
+	// Processing below here calls g.errorf on failure, which does panic(stop).
+	// If we encounter an error, we abort the package.
+	defer func() {
+		e := recover()
+		if e != nil {
+			ok = false
+			if e != stop {
+				panic(e)
+			}
+		}
+	}()
+	g.dir, g.file = filepath.Split(g.path)
+	g.dir = filepath.Clean(g.dir) // No final separator please.
+	if buildV {
+		fmt.Fprintf(os.Stderr, "%s\n", shortPath(g.path))
+	}
+
+	s := bufio.NewScanner(g.r)
+	for s.Scan() {
+		g.lineNum++
+		if !bytes.HasPrefix(s.Bytes(), []byte("//go:generate ")) && !bytes.HasPrefix(s.Bytes(), []byte("//go:generate\t")) {
+			continue
+		}
+		words := g.split(s.Text())
+		if len(words) == 0 {
+			g.errorf("no arguments to directive")
+		}
+		if words[0] == "-command" {
+			g.setShorthand(words)
+			continue
+		}
+		// Run the command line.
+		if buildN || buildX {
+			fmt.Fprintf(os.Stderr, "%s\n", strings.Join(words, " "))
+		}
+		if buildN {
+			continue
+		}
+		g.exec(words)
+	}
+	if s.Err() != nil {
+		g.errorf("error reading %s: %s", shortPath(g.path), s.Err())
+	}
+	return true
+}
+
+// split breaks the line into words, evaluating quoted
+// strings and evaluating environment variables.
+// The initial //go:generate element is dropped.
+func (g *Generator) split(line string) []string {
+	// Parse line, obeying quoted strings.
+	var words []string
+	line = line[len("//go:generate "):]
+	// One (possibly quoted) word per iteration.
+Words:
+	for {
+		line = strings.TrimLeft(line, " \t")
+		if len(line) == 0 {
+			break
+		}
+		if line[0] == '"' {
+			for i := 1; i < len(line); i++ {
+				c := line[i] // Only looking for ASCII so this is OK.
+				switch c {
+				case '\\':
+					if i+1 == len(line) {
+						g.errorf("bad backslash")
+					}
+					i++ // Absorb next byte (If it's a multibyte we'll get an error in Unquote).
+				case '"':
+					word, err := strconv.Unquote(line[0 : i+1])
+					if err != nil {
+						g.errorf("bad quoted string")
+					}
+					words = append(words, word)
+					line = line[i+1:]
+					// Check the next character is space or end of line.
+					if len(line) > 0 && line[0] != ' ' && line[0] != '\t' {
+						g.errorf("expect space after quoted argument")
+					}
+					continue Words
+				}
+			}
+			g.errorf("mismatched quoted string")
+		}
+		i := strings.IndexAny(line, " \t")
+		if i < 0 {
+			i = len(line)
+		}
+		words = append(words, line[0:i])
+		line = line[i:]
+	}
+	// Substitute command if required.
+	if len(words) > 0 && g.commands[words[0]] != nil {
+		// Replace 0th word by command substitution.
+		words = append(g.commands[words[0]], words[1:]...)
+	}
+	// Substitute environment variables.
+	for i, word := range words {
+		words[i] = g.expandEnv(word)
+	}
+	return words
+}
+
+var stop = fmt.Errorf("error in generation")
+
+// errorf logs an error message prefixed with the file and line number.
+// It then exits the program because generation stops at the first error.
+func (g *Generator) errorf(format string, args ...interface{}) {
+	fmt.Fprintf(os.Stderr, "%s:%d: %s\n", shortPath(g.path), g.lineNum,
+		fmt.Sprintf(format, args...))
+	panic(stop)
+}
+
+// expandEnv expands any $XXX invocations in word.
+func (g *Generator) expandEnv(word string) string {
+	if !strings.ContainsRune(word, '$') {
+		return word
+	}
+	var buf bytes.Buffer
+	var w int
+	var r rune
+	for i := 0; i < len(word); i += w {
+		r, w = utf8.DecodeRuneInString(word[i:])
+		if r != '$' {
+			buf.WriteRune(r)
+			continue
+		}
+		w += g.identLength(word[i+w:])
+		envVar := word[i+1 : i+w]
+		var sub string
+		switch envVar {
+		case "GOARCH":
+			sub = runtime.GOARCH
+		case "GOOS":
+			sub = runtime.GOOS
+		case "GOFILE":
+			sub = g.file
+		case "GOPACKAGE":
+			sub = g.pkg
+		default:
+			sub = os.Getenv(envVar)
+		}
+		buf.WriteString(sub)
+	}
+	return buf.String()
+}
+
+// identLength returns the length of the identifier beginning the string.
+func (g *Generator) identLength(word string) int {
+	for i, r := range word {
+		if r == '_' || unicode.IsLetter(r) || unicode.IsDigit(r) {
+			continue
+		}
+		return i
+	}
+	return len(word)
+}
+
+// setShorthand installs a new shorthand as defined by a -command directive.
+func (g *Generator) setShorthand(words []string) {
+	// Create command shorthand.
+	if len(words) == 1 {
+		g.errorf("no command specified for -command")
+	}
+	command := words[1]
+	if g.commands[command] != nil {
+		g.errorf("command %q defined multiply defined", command)
+	}
+	g.commands[command] = words[2:len(words):len(words)] // force later append to make copy
+}
+
+// exec runs the command specified by the argument. The first word is
+// the command name itself.
+func (g *Generator) exec(words []string) {
+	cmd := exec.Command(words[0], words[1:]...)
+	// Standard in and out of generator should be the usual.
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	// Run the command in the package directory.
+	cmd.Dir = g.dir
+	env := []string{
+		"GOARCH=" + runtime.GOARCH,
+		"GOOS=" + runtime.GOOS,
+		"GOFILE=" + g.file,
+		"GOPACKAGE=" + g.pkg,
+	}
+	cmd.Env = mergeEnvLists(env, os.Environ())
+	err := cmd.Run()
+	if err != nil {
+		g.errorf("running %q: %s", words[0], err)
+	}
+}
diff --git a/src/cmd/go/generate_test.go b/src/cmd/go/generate_test.go
new file mode 100644
index 000000000..93c0ae66e
--- /dev/null
+++ b/src/cmd/go/generate_test.go
@@ -0,0 +1,48 @@
+// Copyright 2011 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"reflect"
+	"runtime"
+	"testing"
+)
+
+type splitTest struct {
+	in  string
+	out []string
+}
+
+var splitTests = []splitTest{
+	{"", nil},
+	{"x", []string{"x"}},
+	{" a b\tc ", []string{"a", "b", "c"}},
+	{` " a " `, []string{" a "}},
+	{"$GOARCH", []string{runtime.GOARCH}},
+	{"$GOOS", []string{runtime.GOOS}},
+	{"$GOFILE", []string{"proc.go"}},
+	{"$GOPACKAGE", []string{"sys"}},
+	{"a $XXNOTDEFINEDXX b", []string{"a", "", "b"}},
+	{"/$XXNOTDEFINED/", []string{"//"}},
+	{"yacc -o $GOARCH/yacc_$GOFILE", []string{"go", "tool", "yacc", "-o", runtime.GOARCH + "/yacc_proc.go"}},
+}
+
+func TestGenerateCommandParse(t *testing.T) {
+	g := &Generator{
+		r:        nil, // Unused here.
+		path:     "/usr/ken/sys/proc.go",
+		dir:      "/usr/ken/sys",
+		file:     "proc.go",
+		pkg:      "sys",
+		commands: make(map[string][]string),
+	}
+	g.setShorthand([]string{"-command", "yacc", "go", "tool", "yacc"})
+	for _, test := range splitTests {
+		got := g.split("//go:generate " + test.in)
+		if !reflect.DeepEqual(got, test.out) {
+			t.Errorf("split(%q): got %q expected %q", test.in, got, test.out)
+		}
+	}
+}
diff --git a/src/cmd/go/get.go b/src/cmd/go/get.go
index e708fcf77..a34286f54 100644
--- a/src/cmd/go/get.go
+++ b/src/cmd/go/get.go
@@ -151,7 +151,9 @@ func download(arg string, stk *importStack, getTestDeps bool) {
 	}
 
 	// Only process each package once.
-	if downloadCache[arg] {
+	// (Unless we're fetching test dependencies for this package,
+	// in which case we want to process it again.)
+	if downloadCache[arg] && !getTestDeps {
 		return
 	}
 	downloadCache[arg] = true
diff --git a/src/cmd/go/main.go b/src/cmd/go/main.go
index 5b1194aaa..eb69606de 100644
--- a/src/cmd/go/main.go
+++ b/src/cmd/go/main.go
@@ -79,6 +79,7 @@ var commands = []*Command{
 	cmdEnv,
 	cmdFix,
 	cmdFmt,
+	cmdGenerate,
 	cmdGet,
 	cmdInstall,
 	cmdList,
diff --git a/src/cmd/go/pkg.go b/src/cmd/go/pkg.go
index d45df265b..1af33f037 100644
--- a/src/cmd/go/pkg.go
+++ b/src/cmd/go/pkg.go
@@ -244,6 +244,9 @@ func loadImport(path string, srcDir string, stk *importStack, importPos []token.
 		importPath = dirToImportPath(filepath.Join(srcDir, path))
 	}
 	if p := packageCache[importPath]; p != nil {
+		if perr := disallowInternal(srcDir, p, stk); perr != p {
+			return perr
+		}
 		return reusePackage(p, stk)
 	}
 
@@ -258,11 +261,14 @@ func loadImport(path string, srcDir string, stk *importStack, importPos []token.
 	//
 	// TODO: After Go 1, decide when to pass build.AllowBinary here.
 	// See issue 3268 for mistakes to avoid.
-	bp, err := buildContext.Import(path, srcDir, 0)
+	bp, err := buildContext.Import(path, srcDir, build.ImportComment)
 	bp.ImportPath = importPath
 	if gobin != "" {
 		bp.BinDir = gobin
 	}
+	if err == nil && !isLocal && bp.ImportComment != "" && bp.ImportComment != path {
+		err = fmt.Errorf("code in directory %s expects import %q", bp.Dir, bp.ImportComment)
+	}
 	p.load(stk, bp, err)
 	if p.Error != nil && len(importPos) > 0 {
 		pos := importPos[0]
@@ -270,6 +276,10 @@ func loadImport(path string, srcDir string, stk *importStack, importPos []token.
 		p.Error.Pos = pos.String()
 	}
 
+	if perr := disallowInternal(srcDir, p, stk); perr != p {
+		return perr
+	}
+
 	return p
 }
 
@@ -298,6 +308,75 @@ func reusePackage(p *Package, stk *importStack) *Package {
 	return p
 }
 
+// disallowInternal checks that srcDir is allowed to import p.
+// If the import is allowed, disallowInternal returns the original package p.
+// If not, it returns a new package containing just an appropriate error.
+func disallowInternal(srcDir string, p *Package, stk *importStack) *Package {
+	// golang.org/s/go14internal:
+	// An import of a path containing the element “internal”
+	// is disallowed if the importing code is outside the tree
+	// rooted at the parent of the “internal” directory.
+	//
+	// ... For Go 1.4, we will implement the rule first for $GOROOT, but not $GOPATH.
+
+	// Only applies to $GOROOT.
+	if !p.Standard {
+		return p
+	}
+
+	// The stack includes p.ImportPath.
+	// If that's the only thing on the stack, we started
+	// with a name given on the command line, not an
+	// import. Anything listed on the command line is fine.
+	if len(*stk) == 1 {
+		return p
+	}
+
+	// Check for "internal" element: four cases depending on begin of string and/or end of string.
+	i, ok := findInternal(p.ImportPath)
+	if !ok {
+		return p
+	}
+
+	// Internal is present.
+	// Map import path back to directory corresponding to parent of internal.
+	if i > 0 {
+		i-- // rewind over slash in ".../internal"
+	}
+	parent := p.Dir[:i+len(p.Dir)-len(p.ImportPath)]
+	if hasPathPrefix(filepath.ToSlash(srcDir), filepath.ToSlash(parent)) {
+		return p
+	}
+
+	// Internal is present, and srcDir is outside parent's tree. Not allowed.
+	perr := *p
+	perr.Error = &PackageError{
+		ImportStack: stk.copy(),
+		Err:         "use of internal package not allowed",
+	}
+	perr.Incomplete = true
+	return &perr
+}
+
+// findInternal looks for the final "internal" path element in the given import path.
+// If there isn't one, findInternal returns ok=false.
+// Otherwise, findInternal returns ok=true and the index of the "internal".
+func findInternal(path string) (index int, ok bool) {
+	// Four cases, depending on internal at start/end of string or not.
+	// The order matters: we must return the index of the final element,
+	// because the final one produces the most restrictive requirement
+	// on the importer.
+	switch {
+	case strings.HasSuffix(path, "/internal"):
+		return len(path) - len("internal"), true
+	case strings.Contains(path, "/internal/"):
+		return strings.LastIndex(path, "/internal/") + 1, true
+	case path == "internal", strings.HasPrefix(path, "internal/"):
+		return 0, true
+	}
+	return 0, false
+}
+
 type targetDir int
 
 const (
@@ -482,7 +561,7 @@ func (p *Package) load(stk *importStack, bp *build.Package, err error) *Package
 
 	// Build list of imported packages and full dependency list.
 	imports := make([]*Package, 0, len(p.Imports))
-	deps := make(map[string]bool)
+	deps := make(map[string]*Package)
 	for i, path := range importPaths {
 		if path == "C" {
 			continue
@@ -502,10 +581,10 @@ func (p *Package) load(stk *importStack, bp *build.Package, err error) *Package
 			path = p1.ImportPath
 			importPaths[i] = path
 		}
-		deps[path] = true
+		deps[path] = p1
 		imports = append(imports, p1)
-		for _, dep := range p1.Deps {
-			deps[dep] = true
+		for _, dep := range p1.deps {
+			deps[dep.ImportPath] = dep
 		}
 		if p1.Incomplete {
 			p.Incomplete = true
@@ -519,7 +598,7 @@ func (p *Package) load(stk *importStack, bp *build.Package, err error) *Package
 	}
 	sort.Strings(p.Deps)
 	for _, dep := range p.Deps {
-		p1 := packageCache[dep]
+		p1 := deps[dep]
 		if p1 == nil {
 			panic("impossible: missing entry in package cache for " + dep + " imported by " + p.ImportPath)
 		}
diff --git a/src/cmd/go/test.bash b/src/cmd/go/test.bash
index c62f62940..24640e272 100755
--- a/src/cmd/go/test.bash
+++ b/src/cmd/go/test.bash
@@ -105,6 +105,58 @@ cp -R testdata/local "testdata/$bad"
 testlocal "$bad" 'with bad characters in path'
 rm -rf "testdata/$bad"
 
+TEST 'internal packages in $GOROOT are respected'
+if ./testgo build -v ./testdata/testinternal >testdata/std.out 2>&1; then
+	echo "go build ./testdata/testinternal succeeded incorrectly"
+	ok=false
+elif ! grep 'use of internal package not allowed' testdata/std.out >/dev/null; then
+	echo "wrong error message for testdata/testinternal"
+	cat std.out
+	ok=false
+fi
+
+TEST 'internal packages outside $GOROOT are not respected'
+if ! ./testgo build -v ./testdata/testinternal2; then
+	echo "go build ./testdata/testinternal2 failed"
+	ok=false
+fi
+
+export GOPATH=$(pwd)/testdata/importcom
+TEST 'import comment - match'
+if ! ./testgo build ./testdata/importcom/works.go; then
+	echo 'go build ./testdata/importcom/works.go failed'
+	ok=false
+fi
+TEST 'import comment - mismatch'
+if ./testgo build ./testdata/importcom/wrongplace.go 2>testdata/err; then
+	echo 'go build ./testdata/importcom/wrongplace.go suceeded'
+	ok=false
+elif ! grep 'wrongplace expects import "my/x"' testdata/err >/dev/null; then
+	echo 'go build did not mention incorrect import:'
+	cat testdata/err
+	ok=false
+fi
+TEST 'import comment - syntax error'
+if ./testgo build ./testdata/importcom/bad.go 2>testdata/err; then
+	echo 'go build ./testdata/importcom/bad.go suceeded'
+	ok=false
+elif ! grep 'cannot parse import comment' testdata/err >/dev/null; then
+	echo 'go build did not mention syntax error:'
+	cat testdata/err
+	ok=false
+fi
+TEST 'import comment - conflict'
+if ./testgo build ./testdata/importcom/conflict.go 2>testdata/err; then
+	echo 'go build ./testdata/importcom/conflict.go suceeded'
+	ok=false
+elif ! grep 'found import comments' testdata/err >/dev/null; then
+	echo 'go build did not mention comment conflict:'
+	cat testdata/err
+	ok=false
+fi
+rm -f ./testdata/err
+unset GOPATH
+
 TEST error message for syntax error in test go file says FAIL
 export GOPATH=$(pwd)/testdata
 if ./testgo test syntaxerror 2>testdata/err; then
@@ -527,6 +579,17 @@ TEST go get cover
 unset GOPATH
 rm -rf $d
 
+TEST go get -t "code.google.com/p/go-get-issue-8181/{a,b}"
+d=$(TMPDIR=/var/tmp mktemp -d -t testgoXXX)
+export GOPATH=$d
+if ./testgo get -t code.google.com/p/go-get-issue-8181/{a,b}; then
+	./testgo list ... | grep go.tools/godoc > /dev/null || ok=false
+else
+	ok=false
+fi
+unset GOPATH
+rm -rf $d
+
 TEST shadowing logic
 export GOPATH=$(pwd)/testdata/shadow/root1:$(pwd)/testdata/shadow/root2
 
@@ -815,6 +878,33 @@ elif ! grep 'File with non-runnable example was built.' testdata/std.out > /dev/
 	ok=false
 fi
 
+TEST 'go generate handles simple command'
+if ! ./testgo generate ./testdata/generate/test1.go > testdata/std.out; then
+	echo "go test ./testdata/generate/test1.go failed to run"
+	ok=false
+elif ! grep 'Success' testdata/std.out > /dev/null; then
+	echo "go test ./testdata/generate/test1.go generated wrong output"
+	ok=false
+fi
+
+TEST 'go generate handles command alias'
+if ! ./testgo generate ./testdata/generate/test2.go > testdata/std.out; then
+	echo "go test ./testdata/generate/test2.go failed to run"
+	ok=false
+elif ! grep 'Now is the time for all good men' testdata/std.out > /dev/null; then
+	echo "go test ./testdata/generate/test2.go generated wrong output"
+	ok=false
+fi
+
+TEST 'go generate variable substitution'
+if ! ./testgo generate ./testdata/generate/test3.go > testdata/std.out; then
+	echo "go test ./testdata/generate/test3.go failed to run"
+	ok=false
+elif ! grep "$GOARCH test3.go p xyzp/test3.go/123" testdata/std.out > /dev/null; then
+	echo "go test ./testdata/generate/test3.go generated wrong output"
+	ok=false
+fi
+
 # clean up
 if $started; then stop; fi
 rm -rf testdata/bin testdata/bin1
diff --git a/src/cmd/go/testdata/generate/test1.go b/src/cmd/go/testdata/generate/test1.go
new file mode 100644
index 000000000..1f05734f0
--- /dev/null
+++ b/src/cmd/go/testdata/generate/test1.go
@@ -0,0 +1,13 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Simple test for go generate.
+
+// We include a build tag that go generate should ignore.
+
+// +build ignore
+
+//go:generate echo Success
+
+package p
diff --git a/src/cmd/go/testdata/generate/test2.go b/src/cmd/go/testdata/generate/test2.go
new file mode 100644
index 000000000..ef1a3d951
--- /dev/null
+++ b/src/cmd/go/testdata/generate/test2.go
@@ -0,0 +1,10 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test that go generate handles command aliases.
+
+//go:generate -command run echo Now is the time
+//go:generate run for all good men
+
+package p
diff --git a/src/cmd/go/testdata/generate/test3.go b/src/cmd/go/testdata/generate/test3.go
new file mode 100644
index 000000000..41ffb7ea8
--- /dev/null
+++ b/src/cmd/go/testdata/generate/test3.go
@@ -0,0 +1,9 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test go generate variable substitution.
+
+//go:generate echo $GOARCH $GOFILE $GOPACKAGE xyz$GOPACKAGE/$GOFILE/123
+
+package p
diff --git a/src/cmd/go/testdata/importcom/bad.go b/src/cmd/go/testdata/importcom/bad.go
new file mode 100644
index 000000000..e104c2e99
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/bad.go
@@ -0,0 +1,3 @@
+package p
+
+import "bad"
diff --git a/src/cmd/go/testdata/importcom/conflict.go b/src/cmd/go/testdata/importcom/conflict.go
new file mode 100644
index 000000000..995556c51
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/conflict.go
@@ -0,0 +1,3 @@
+package p
+
+import "conflict"
diff --git a/src/cmd/go/testdata/importcom/src/bad/bad.go b/src/cmd/go/testdata/importcom/src/bad/bad.go
new file mode 100644
index 000000000..bc51fd3fd
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/src/bad/bad.go
@@ -0,0 +1 @@
+package bad // import
diff --git a/src/cmd/go/testdata/importcom/src/conflict/a.go b/src/cmd/go/testdata/importcom/src/conflict/a.go
new file mode 100644
index 000000000..2d6770351
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/src/conflict/a.go
@@ -0,0 +1 @@
+package conflict // import "a"
diff --git a/src/cmd/go/testdata/importcom/src/conflict/b.go b/src/cmd/go/testdata/importcom/src/conflict/b.go
new file mode 100644
index 000000000..8fcfb3c8b
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/src/conflict/b.go
@@ -0,0 +1 @@
+package conflict /* import "b" */
diff --git a/src/cmd/go/testdata/importcom/src/works/x/x.go b/src/cmd/go/testdata/importcom/src/works/x/x.go
new file mode 100644
index 000000000..044c6eca8
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/src/works/x/x.go
@@ -0,0 +1 @@
+package x // import "works/x"
diff --git a/src/cmd/go/testdata/importcom/src/works/x/x1.go b/src/cmd/go/testdata/importcom/src/works/x/x1.go
new file mode 100644
index 000000000..2449b29df
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/src/works/x/x1.go
@@ -0,0 +1 @@
+package x // important! not an import comment
diff --git a/src/cmd/go/testdata/importcom/src/wrongplace/x.go b/src/cmd/go/testdata/importcom/src/wrongplace/x.go
new file mode 100644
index 000000000..b89849da7
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/src/wrongplace/x.go
@@ -0,0 +1 @@
+package x // import "my/x"
diff --git a/src/cmd/go/testdata/importcom/works.go b/src/cmd/go/testdata/importcom/works.go
new file mode 100644
index 000000000..31b55d08a
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/works.go
@@ -0,0 +1,3 @@
+package p
+
+import _ "works/x"
diff --git a/src/cmd/go/testdata/importcom/wrongplace.go b/src/cmd/go/testdata/importcom/wrongplace.go
new file mode 100644
index 000000000..e2535e01a
--- /dev/null
+++ b/src/cmd/go/testdata/importcom/wrongplace.go
@@ -0,0 +1,3 @@
+package p
+
+import "wrongplace"
diff --git a/src/cmd/go/testdata/testinternal/p.go b/src/cmd/go/testdata/testinternal/p.go
new file mode 100644
index 000000000..e3558a53b
--- /dev/null
+++ b/src/cmd/go/testdata/testinternal/p.go
@@ -0,0 +1,3 @@
+package p
+
+import _ "net/http/internal"
diff --git a/src/cmd/go/testdata/testinternal2/p.go b/src/cmd/go/testdata/testinternal2/p.go
new file mode 100644
index 000000000..c594f5c5e
--- /dev/null
+++ b/src/cmd/go/testdata/testinternal2/p.go
@@ -0,0 +1,3 @@
+package p
+
+import _ "./x/y/z/internal/w"
diff --git a/src/cmd/go/testdata/testinternal2/x/y/z/internal/w/w.go b/src/cmd/go/testdata/testinternal2/x/y/z/internal/w/w.go
new file mode 100644
index 000000000..a796c0b5f
--- /dev/null
+++ b/src/cmd/go/testdata/testinternal2/x/y/z/internal/w/w.go
@@ -0,0 +1 @@
+package w
diff --git a/src/cmd/go/vcs_test.go b/src/cmd/go/vcs_test.go
index f9bf75fef..14d681ba6 100644
--- a/src/cmd/go/vcs_test.go
+++ b/src/cmd/go/vcs_test.go
@@ -12,6 +12,9 @@ import (
 // Test that RepoRootForImportPath creates the correct RepoRoot for a given importPath.
 // TODO(cmang): Add tests for SVN and BZR.
 func TestRepoRootForImportPath(t *testing.T) {
+	if testing.Short() {
+		t.Skip("skipping test to avoid external network")
+	}
 	switch runtime.GOOS {
 	case "nacl", "android":
 		t.Skipf("no networking available on %s", runtime.GOOS)
@@ -106,7 +109,7 @@ func TestRepoRootForImportPath(t *testing.T) {
 
 		if want == nil {
 			if err == nil {
-				t.Errorf("RepoRootForImport(%q): Error expected but not received")
+				t.Errorf("RepoRootForImport(%q): Error expected but not received", test.path)
 			}
 			continue
 		}
diff --git a/src/cmd/gofmt/gofmt.go b/src/cmd/gofmt/gofmt.go
index 576cae522..f322a2b0a 100644
--- a/src/cmd/gofmt/gofmt.go
+++ b/src/cmd/gofmt/gofmt.go
@@ -122,7 +122,7 @@ func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error
 			fmt.Fprintln(out, filename)
 		}
 		if *write {
-			err = ioutil.WriteFile(filename, res, 0)
+			err = ioutil.WriteFile(filename, res, 0644)
 			if err != nil {
 				return err
 			}
@@ -186,6 +186,11 @@ func gofmtMain() {
 	initRewrite()
 
 	if flag.NArg() == 0 {
+		if *write {
+			fmt.Fprintln(os.Stderr, "error: cannot use -w with standard input")
+			exitCode = 2
+			return
+		}
 		if err := processFile("<standard input>", os.Stdin, os.Stdout, true); err != nil {
 			report(err)
 		}
@@ -277,14 +282,14 @@ func parse(fset *token.FileSet, filename string, src []byte, stdin bool) (*ast.F
 	// into a function body.  This handles expressions too.
 	// Insert using a ;, not a newline, so that the line numbers
 	// in fsrc match the ones in src.
-	fsrc := append(append([]byte("package p; func _() {"), src...), '}')
+	fsrc := append(append([]byte("package p; func _() {"), src...), '\n', '}')
 	file, err = parser.ParseFile(fset, filename, fsrc, parserMode)
 	if err == nil {
 		adjust := func(orig, src []byte) []byte {
 			// Remove the wrapping.
 			// Gofmt has turned the ; into a \n\n.
 			src = src[len("package p\n\nfunc _() {"):]
-			src = src[:len(src)-len("}\n")]
+			src = src[:len(src)-len("\n}\n")]
 			// Gofmt has also indented the function body one level.
 			// Remove that indent.
 			src = bytes.Replace(src, []byte("\n\t"), []byte("\n"), -1)
diff --git a/src/cmd/gofmt/gofmt_test.go b/src/cmd/gofmt/gofmt_test.go
index ca44f3dcf..d1edb7bcc 100644
--- a/src/cmd/gofmt/gofmt_test.go
+++ b/src/cmd/gofmt/gofmt_test.go
@@ -6,18 +6,60 @@ package main
 
 import (
 	"bytes"
+	"flag"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
+	"text/scanner"
 )
 
-func runTest(t *testing.T, in, out, flags string) {
+var update = flag.Bool("update", false, "update .golden files")
+
+// gofmtFlags looks for a comment of the form
+//
+//	//gofmt flags
+//
+// within the first maxLines lines of the given file,
+// and returns the flags string, if any. Otherwise it
+// returns the empty string.
+func gofmtFlags(filename string, maxLines int) string {
+	f, err := os.Open(filename)
+	if err != nil {
+		return "" // ignore errors - they will be found later
+	}
+	defer f.Close()
+
+	// initialize scanner
+	var s scanner.Scanner
+	s.Init(f)
+	s.Error = func(*scanner.Scanner, string) {}       // ignore errors
+	s.Mode = scanner.GoTokens &^ scanner.SkipComments // want comments
+
+	// look for //gofmt comment
+	for s.Line <= maxLines {
+		switch s.Scan() {
+		case scanner.Comment:
+			const prefix = "//gofmt "
+			if t := s.TokenText(); strings.HasPrefix(t, prefix) {
+				return strings.TrimSpace(t[len(prefix):])
+			}
+		case scanner.EOF:
+			return ""
+		}
+
+	}
+
+	return ""
+}
+
+func runTest(t *testing.T, in, out string) {
 	// process flags
 	*simplifyAST = false
 	*rewriteRule = ""
 	stdin := false
-	for _, flag := range strings.Split(flags, " ") {
+	for _, flag := range strings.Split(gofmtFlags(in, 20), " ") {
 		elts := strings.SplitN(flag, "=", 2)
 		name := elts[0]
 		value := ""
@@ -56,6 +98,17 @@ func runTest(t *testing.T, in, out, flags string) {
 	}
 
 	if got := buf.Bytes(); !bytes.Equal(got, expected) {
+		if *update {
+			if in != out {
+				if err := ioutil.WriteFile(out, got, 0666); err != nil {
+					t.Error(err)
+				}
+				return
+			}
+			// in == out: don't accidentally destroy input
+			t.Errorf("WARNING: -update did not rewrite input file %s", in)
+		}
+
 		t.Errorf("(gofmt %s) != %s (see %s.gofmt)", in, out, in)
 		d, err := diff(expected, got)
 		if err == nil {
@@ -67,53 +120,37 @@ func runTest(t *testing.T, in, out, flags string) {
 	}
 }
 
-var tests = []struct {
-	in, flags string
-}{
-	{"gofmt.go", ""},
-	{"gofmt_test.go", ""},
-	{"testdata/composites.input", "-s"},
-	{"testdata/slices1.input", "-s"},
-	{"testdata/slices2.input", "-s"},
-	{"testdata/ranges.input", "-s"},
-	{"testdata/old.input", ""},
-	{"testdata/rewrite1.input", "-r=Foo->Bar"},
-	{"testdata/rewrite2.input", "-r=int->bool"},
-	{"testdata/rewrite3.input", "-r=x->x"},
-	{"testdata/rewrite4.input", "-r=(x)->x"},
-	{"testdata/rewrite5.input", "-r=x+x->2*x"},
-	{"testdata/rewrite6.input", "-r=fun(x)->Fun(x)"},
-	{"testdata/rewrite7.input", "-r=fun(x...)->Fun(x)"},
-	{"testdata/rewrite8.input", "-r=interface{}->int"},
-	{"testdata/stdin*.input", "-stdin"},
-	{"testdata/comments.input", ""},
-	{"testdata/import.input", ""},
-	{"testdata/crlf.input", ""},        // test case for issue 3961; see also TestCRLF
-	{"testdata/typeswitch.input", ""},  // test case for issue 4470
-	{"testdata/emptydecl.input", "-s"}, // test case for issue 7631
-}
-
+// TestRewrite processes testdata/*.input files and compares them to the
+// corresponding testdata/*.golden files. The gofmt flags used to process
+// a file must be provided via a comment of the form
+//
+//	//gofmt flags
+//
+// in the processed file within the first 20 lines, if any.
 func TestRewrite(t *testing.T) {
-	for _, test := range tests {
-		match, err := filepath.Glob(test.in)
-		if err != nil {
-			t.Error(err)
-			continue
+	// determine input files
+	match, err := filepath.Glob("testdata/*.input")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// add larger examples
+	match = append(match, "gofmt.go", "gofmt_test.go")
+
+	for _, in := range match {
+		out := in // for files where input and output are identical
+		if strings.HasSuffix(in, ".input") {
+			out = in[:len(in)-len(".input")] + ".golden"
 		}
-		for _, in := range match {
-			out := in
-			if strings.HasSuffix(in, ".input") {
-				out = in[:len(in)-len(".input")] + ".golden"
-			}
-			runTest(t, in, out, test.flags)
-			if in != out {
-				// Check idempotence.
-				runTest(t, out, out, test.flags)
-			}
+		runTest(t, in, out)
+		if in != out {
+			// Check idempotence.
+			runTest(t, out, out)
 		}
 	}
 }
 
+// Test case for issue 3961.
 func TestCRLF(t *testing.T) {
 	const input = "testdata/crlf.input"   // must contain CR/LF's
 	const golden = "testdata/crlf.golden" // must not contain any CR's
diff --git a/src/cmd/gofmt/testdata/composites.golden b/src/cmd/gofmt/testdata/composites.golden
index b2825e732..fc9c98e62 100644
--- a/src/cmd/gofmt/testdata/composites.golden
+++ b/src/cmd/gofmt/testdata/composites.golden
@@ -1,3 +1,5 @@
+//gofmt -s
+
 package P
 
 type T struct {
diff --git a/src/cmd/gofmt/testdata/composites.input b/src/cmd/gofmt/testdata/composites.input
index 7210dafc9..fc7598af9 100644
--- a/src/cmd/gofmt/testdata/composites.input
+++ b/src/cmd/gofmt/testdata/composites.input
@@ -1,3 +1,5 @@
+//gofmt -s
+
 package P
 
 type T struct {
diff --git a/src/cmd/gofmt/testdata/crlf.golden b/src/cmd/gofmt/testdata/crlf.golden
index 57679f770..193dbacc7 100644
--- a/src/cmd/gofmt/testdata/crlf.golden
+++ b/src/cmd/gofmt/testdata/crlf.golden
@@ -2,6 +2,7 @@
 	Source containing CR/LF line endings.
 	The gofmt'ed output must only have LF
 	line endings.
+	Test case for issue 3961.
 */
 package main
 
diff --git a/src/cmd/gofmt/testdata/crlf.input b/src/cmd/gofmt/testdata/crlf.input
index 61a1aa0b4..ae7e14dbf 100644
--- a/src/cmd/gofmt/testdata/crlf.input
+++ b/src/cmd/gofmt/testdata/crlf.input
@@ -2,6 +2,7 @@
 	Source containing CR/LF line endings.

 	The gofmt'ed output must only have LF

 	line endings.

+	Test case for issue 3961.

 */

 package main

 

diff --git a/src/cmd/gofmt/testdata/emptydecl.golden b/src/cmd/gofmt/testdata/emptydecl.golden
index 9fe62c973..33d6435e0 100644
--- a/src/cmd/gofmt/testdata/emptydecl.golden
+++ b/src/cmd/gofmt/testdata/emptydecl.golden
@@ -1,3 +1,7 @@
+//gofmt -s
+
+// Test case for issue 7631.
+
 package main
 
 // Keep this declaration
diff --git a/src/cmd/gofmt/testdata/emptydecl.input b/src/cmd/gofmt/testdata/emptydecl.input
index d1cab00ef..4948a61f0 100644
--- a/src/cmd/gofmt/testdata/emptydecl.input
+++ b/src/cmd/gofmt/testdata/emptydecl.input
@@ -1,3 +1,7 @@
+//gofmt -s
+
+// Test case for issue 7631.
+
 package main
 
 // Keep this declaration
diff --git a/src/cmd/gofmt/testdata/ranges.golden b/src/cmd/gofmt/testdata/ranges.golden
index 42168526d..506b3a035 100644
--- a/src/cmd/gofmt/testdata/ranges.golden
+++ b/src/cmd/gofmt/testdata/ranges.golden
@@ -1,3 +1,5 @@
+//gofmt -s
+
 // Test cases for range simplification.
 package p
 
diff --git a/src/cmd/gofmt/testdata/ranges.input b/src/cmd/gofmt/testdata/ranges.input
index 4b02d5175..df5f8333c 100644
--- a/src/cmd/gofmt/testdata/ranges.input
+++ b/src/cmd/gofmt/testdata/ranges.input
@@ -1,3 +1,5 @@
+//gofmt -s
+
 // Test cases for range simplification.
 package p
 
diff --git a/src/cmd/gofmt/testdata/rewrite1.golden b/src/cmd/gofmt/testdata/rewrite1.golden
index d9beb3705..3ee5373a7 100644
--- a/src/cmd/gofmt/testdata/rewrite1.golden
+++ b/src/cmd/gofmt/testdata/rewrite1.golden
@@ -1,3 +1,5 @@
+//gofmt -r=Foo->Bar
+
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite1.input b/src/cmd/gofmt/testdata/rewrite1.input
index bdb894320..a84c8f781 100644
--- a/src/cmd/gofmt/testdata/rewrite1.input
+++ b/src/cmd/gofmt/testdata/rewrite1.input
@@ -1,3 +1,5 @@
+//gofmt -r=Foo->Bar
+
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite2.golden b/src/cmd/gofmt/testdata/rewrite2.golden
index 64c67ffa6..f980e0353 100644
--- a/src/cmd/gofmt/testdata/rewrite2.golden
+++ b/src/cmd/gofmt/testdata/rewrite2.golden
@@ -1,3 +1,5 @@
+//gofmt -r=int->bool
+
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite2.input b/src/cmd/gofmt/testdata/rewrite2.input
index 21171447a..489be4e07 100644
--- a/src/cmd/gofmt/testdata/rewrite2.input
+++ b/src/cmd/gofmt/testdata/rewrite2.input
@@ -1,3 +1,5 @@
+//gofmt -r=int->bool
+
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite3.golden b/src/cmd/gofmt/testdata/rewrite3.golden
index 0d16d1601..261a220c6 100644
--- a/src/cmd/gofmt/testdata/rewrite3.golden
+++ b/src/cmd/gofmt/testdata/rewrite3.golden
@@ -1,3 +1,5 @@
+//gofmt -r=x->x
+
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite3.input b/src/cmd/gofmt/testdata/rewrite3.input
index 0d16d1601..261a220c6 100644
--- a/src/cmd/gofmt/testdata/rewrite3.input
+++ b/src/cmd/gofmt/testdata/rewrite3.input
@@ -1,3 +1,5 @@
+//gofmt -r=x->x
+
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite4.golden b/src/cmd/gofmt/testdata/rewrite4.golden
index 8dfc81a07..b05547b4b 100644
--- a/src/cmd/gofmt/testdata/rewrite4.golden
+++ b/src/cmd/gofmt/testdata/rewrite4.golden
@@ -1,3 +1,5 @@
+//gofmt -r=(x)->x
+
 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite4.input b/src/cmd/gofmt/testdata/rewrite4.input
index 164cc0451..081709920 100644
--- a/src/cmd/gofmt/testdata/rewrite4.input
+++ b/src/cmd/gofmt/testdata/rewrite4.input
@@ -1,3 +1,5 @@
+//gofmt -r=(x)->x
+
 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite5.golden b/src/cmd/gofmt/testdata/rewrite5.golden
index 5a448a63d..9beb34aee 100644
--- a/src/cmd/gofmt/testdata/rewrite5.golden
+++ b/src/cmd/gofmt/testdata/rewrite5.golden
@@ -1,3 +1,5 @@
+//gofmt -r=x+x->2*x
+
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite5.input b/src/cmd/gofmt/testdata/rewrite5.input
index 0d759e69b..d7a6122d0 100644
--- a/src/cmd/gofmt/testdata/rewrite5.input
+++ b/src/cmd/gofmt/testdata/rewrite5.input
@@ -1,3 +1,5 @@
+//gofmt -r=x+x->2*x
+
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite6.golden b/src/cmd/gofmt/testdata/rewrite6.golden
index e565dbdd9..48ec9aa0d 100644
--- a/src/cmd/gofmt/testdata/rewrite6.golden
+++ b/src/cmd/gofmt/testdata/rewrite6.golden
@@ -1,3 +1,5 @@
+//gofmt -r=fun(x)->Fun(x)
+
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite6.input b/src/cmd/gofmt/testdata/rewrite6.input
index 8c088b3e8..b085a84fe 100644
--- a/src/cmd/gofmt/testdata/rewrite6.input
+++ b/src/cmd/gofmt/testdata/rewrite6.input
@@ -1,3 +1,5 @@
+//gofmt -r=fun(x)->Fun(x)
+
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite7.golden b/src/cmd/gofmt/testdata/rewrite7.golden
index 29babad9f..8386a0b2a 100644
--- a/src/cmd/gofmt/testdata/rewrite7.golden
+++ b/src/cmd/gofmt/testdata/rewrite7.golden
@@ -1,3 +1,5 @@
+//gofmt -r=fun(x...)->Fun(x)
+
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite7.input b/src/cmd/gofmt/testdata/rewrite7.input
index 073e2a3e6..c1984708e 100644
--- a/src/cmd/gofmt/testdata/rewrite7.input
+++ b/src/cmd/gofmt/testdata/rewrite7.input
@@ -1,3 +1,5 @@
+//gofmt -r=fun(x...)->Fun(x)
+
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite8.golden b/src/cmd/gofmt/testdata/rewrite8.golden
index cfc452b03..62f0419df 100644
--- a/src/cmd/gofmt/testdata/rewrite8.golden
+++ b/src/cmd/gofmt/testdata/rewrite8.golden
@@ -1,3 +1,5 @@
+//gofmt -r=interface{}->int
+
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/rewrite8.input b/src/cmd/gofmt/testdata/rewrite8.input
index 235efa91c..7964c5c75 100644
--- a/src/cmd/gofmt/testdata/rewrite8.input
+++ b/src/cmd/gofmt/testdata/rewrite8.input
@@ -1,3 +1,5 @@
+//gofmt -r=interface{}->int
+
 // Copyright 2013 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
diff --git a/src/cmd/gofmt/testdata/slices1.golden b/src/cmd/gofmt/testdata/slices1.golden
index 6633a5e00..04bc16f21 100644
--- a/src/cmd/gofmt/testdata/slices1.golden
+++ b/src/cmd/gofmt/testdata/slices1.golden
@@ -1,3 +1,5 @@
+//gofmt -s
+
 // Test cases for slice expression simplification.
 package p
 
diff --git a/src/cmd/gofmt/testdata/slices1.input b/src/cmd/gofmt/testdata/slices1.input
index 27e9cb8fe..1f25c43cc 100644
--- a/src/cmd/gofmt/testdata/slices1.input
+++ b/src/cmd/gofmt/testdata/slices1.input
@@ -1,3 +1,5 @@
+//gofmt -s
+
 // Test cases for slice expression simplification.
 package p
 
diff --git a/src/cmd/gofmt/testdata/slices2.golden b/src/cmd/gofmt/testdata/slices2.golden
index 433788e1e..ab657004e 100644
--- a/src/cmd/gofmt/testdata/slices2.golden
+++ b/src/cmd/gofmt/testdata/slices2.golden
@@ -1,3 +1,5 @@
+//gofmt -s
+
 // Test cases for slice expression simplification.
 // Because of a dot import, these slices must remain untouched.
 package p
diff --git a/src/cmd/gofmt/testdata/slices2.input b/src/cmd/gofmt/testdata/slices2.input
index 433788e1e..ab657004e 100644
--- a/src/cmd/gofmt/testdata/slices2.input
+++ b/src/cmd/gofmt/testdata/slices2.input
@@ -1,3 +1,5 @@
+//gofmt -s
+
 // Test cases for slice expression simplification.
 // Because of a dot import, these slices must remain untouched.
 package p
diff --git a/src/cmd/gofmt/testdata/stdin1.golden b/src/cmd/gofmt/testdata/stdin1.golden
index ff8b0b7ab..9e4dcd20f 100644
--- a/src/cmd/gofmt/testdata/stdin1.golden
+++ b/src/cmd/gofmt/testdata/stdin1.golden
@@ -1,3 +1,5 @@
+	//gofmt -stdin
+
 	if x {
 		y
 	}
diff --git a/src/cmd/gofmt/testdata/stdin1.golden.gofmt b/src/cmd/gofmt/testdata/stdin1.golden.gofmt
deleted file mode 100644
index 1f888877d..000000000
--- a/src/cmd/gofmt/testdata/stdin1.golden.gofmt
+++ /dev/null
@@ -1,3 +0,0 @@
-	if x {
-	y
-}
diff --git a/src/cmd/gofmt/testdata/stdin1.input b/src/cmd/gofmt/testdata/stdin1.input
index ff8b0b7ab..9e4dcd20f 100644
--- a/src/cmd/gofmt/testdata/stdin1.input
+++ b/src/cmd/gofmt/testdata/stdin1.input
@@ -1,3 +1,5 @@
+	//gofmt -stdin
+
 	if x {
 		y
 	}
diff --git a/src/cmd/gofmt/testdata/stdin1.input.gofmt b/src/cmd/gofmt/testdata/stdin1.input.gofmt
deleted file mode 100644
index 1f888877d..000000000
--- a/src/cmd/gofmt/testdata/stdin1.input.gofmt
+++ /dev/null
@@ -1,3 +0,0 @@
-	if x {
-	y
-}
diff --git a/src/cmd/gofmt/testdata/stdin2.golden b/src/cmd/gofmt/testdata/stdin2.golden
index 7eb1b54fe..57df35540 100644
--- a/src/cmd/gofmt/testdata/stdin2.golden
+++ b/src/cmd/gofmt/testdata/stdin2.golden
@@ -1,4 +1,4 @@
-
+//gofmt -stdin
 
 var x int
 
diff --git a/src/cmd/gofmt/testdata/stdin2.golden.gofmt b/src/cmd/gofmt/testdata/stdin2.golden.gofmt
deleted file mode 100644
index 85e800300..000000000
--- a/src/cmd/gofmt/testdata/stdin2.golden.gofmt
+++ /dev/null
@@ -1,10 +0,0 @@
-
-
-
-var x int
-
-func f() {
-	y := z
-}
-
-
diff --git a/src/cmd/gofmt/testdata/stdin2.input b/src/cmd/gofmt/testdata/stdin2.input
index 99defd2d1..69d6bdd68 100644
--- a/src/cmd/gofmt/testdata/stdin2.input
+++ b/src/cmd/gofmt/testdata/stdin2.input
@@ -1,4 +1,4 @@
-
+//gofmt -stdin
 
 var x int
 
diff --git a/src/cmd/gofmt/testdata/stdin2.input.gofmt b/src/cmd/gofmt/testdata/stdin2.input.gofmt
deleted file mode 100644
index 7eb1b54fe..000000000
--- a/src/cmd/gofmt/testdata/stdin2.input.gofmt
+++ /dev/null
@@ -1,11 +0,0 @@
-
-
-var x int
-
-func f() {
-	y := z
-	/* this is a comment */
-	// this is a comment too
-}
-
-
diff --git a/src/cmd/gofmt/testdata/stdin3.golden b/src/cmd/gofmt/testdata/stdin3.golden
index 1bf2f5a48..d6da0e417 100644
--- a/src/cmd/gofmt/testdata/stdin3.golden
+++ b/src/cmd/gofmt/testdata/stdin3.golden
@@ -1,3 +1,4 @@
+		//gofmt -stdin
 
 		/* note: no newline at end of file */
 		for i := 0; i < 10; i++ {
diff --git a/src/cmd/gofmt/testdata/stdin3.golden.gofmt b/src/cmd/gofmt/testdata/stdin3.golden.gofmt
deleted file mode 100644
index b4d1d4663..000000000
--- a/src/cmd/gofmt/testdata/stdin3.golden.gofmt
+++ /dev/null
@@ -1,7 +0,0 @@
-
-
-		/* note: no newline at end of file */
-		for i := 0; i < 10; i++ {
-			s += i
-		}
-	
\ No newline at end of file
diff --git a/src/cmd/gofmt/testdata/stdin3.input b/src/cmd/gofmt/testdata/stdin3.input
index d963bd0d2..ab46c1063 100644
--- a/src/cmd/gofmt/testdata/stdin3.input
+++ b/src/cmd/gofmt/testdata/stdin3.input
@@ -1,3 +1,4 @@
+		//gofmt -stdin
 
 		/* note: no newline at end of file */
 		for i := 0; i < 10; i++ { s += i }
diff --git a/src/cmd/gofmt/testdata/stdin3.input.gofmt b/src/cmd/gofmt/testdata/stdin3.input.gofmt
deleted file mode 100644
index b4d1d4663..000000000
--- a/src/cmd/gofmt/testdata/stdin3.input.gofmt
+++ /dev/null
@@ -1,7 +0,0 @@
-
-
-		/* note: no newline at end of file */
-		for i := 0; i < 10; i++ {
-			s += i
-		}
-	
\ No newline at end of file
diff --git a/src/cmd/gofmt/testdata/stdin4.golden b/src/cmd/gofmt/testdata/stdin4.golden
index 5f7343551..0c7acace5 100644
--- a/src/cmd/gofmt/testdata/stdin4.golden
+++ b/src/cmd/gofmt/testdata/stdin4.golden
@@ -1,3 +1,5 @@
+	//gofmt -stdin
+
 	// comment
 
 	i := 0
diff --git a/src/cmd/gofmt/testdata/stdin4.golden.gofmt b/src/cmd/gofmt/testdata/stdin4.golden.gofmt
deleted file mode 100644
index 5f7343551..000000000
--- a/src/cmd/gofmt/testdata/stdin4.golden.gofmt
+++ /dev/null
@@ -1,3 +0,0 @@
-	// comment
-
-	i := 0
diff --git a/src/cmd/gofmt/testdata/stdin4.input b/src/cmd/gofmt/testdata/stdin4.input
index f02a54fb1..1fc73f31e 100644
--- a/src/cmd/gofmt/testdata/stdin4.input
+++ b/src/cmd/gofmt/testdata/stdin4.input
@@ -1,3 +1,5 @@
+	//gofmt -stdin
+
 	// comment
 	
 	i := 0
diff --git a/src/cmd/gofmt/testdata/stdin4.input.gofmt b/src/cmd/gofmt/testdata/stdin4.input.gofmt
deleted file mode 100644
index 5f7343551..000000000
--- a/src/cmd/gofmt/testdata/stdin4.input.gofmt
+++ /dev/null
@@ -1,3 +0,0 @@
-	// comment
-
-	i := 0
diff --git a/src/cmd/gofmt/testdata/stdin5.golden b/src/cmd/gofmt/testdata/stdin5.golden
new file mode 100644
index 000000000..31ce6b248
--- /dev/null
+++ b/src/cmd/gofmt/testdata/stdin5.golden
@@ -0,0 +1,3 @@
+//gofmt -stdin
+
+i := 5 // Line comment without newline.
\ No newline at end of file
diff --git a/src/cmd/gofmt/testdata/stdin5.input b/src/cmd/gofmt/testdata/stdin5.input
new file mode 100644
index 000000000..0a7c97d18
--- /dev/null
+++ b/src/cmd/gofmt/testdata/stdin5.input
@@ -0,0 +1,3 @@
+//gofmt -stdin
+
+i  :=5// Line comment without newline.
\ No newline at end of file
diff --git a/src/cmd/nm/elf.go b/src/cmd/internal/objfile/elf.go
index 5aaa194dd..8495fa753 100644
--- a/src/cmd/nm/elf.go
+++ b/src/cmd/internal/objfile/elf.go
@@ -4,24 +4,29 @@
 
 // Parsing of ELF executables (Linux, FreeBSD, and so on).
 
-package main
+package objfile
 
 import (
 	"debug/elf"
 	"os"
 )
 
-func elfSymbols(f *os.File) []Sym {
-	p, err := elf.NewFile(f)
+type elfFile struct {
+	elf *elf.File
+}
+
+func openElf(r *os.File) (rawFile, error) {
+	f, err := elf.NewFile(r)
 	if err != nil {
-		errorf("parsing %s: %v", f.Name(), err)
-		return nil
+		return nil, err
 	}
+	return &elfFile{f}, nil
+}
 
-	elfSyms, err := p.Symbols()
+func (f *elfFile) symbols() ([]Sym, error) {
+	elfSyms, err := f.elf.Symbols()
 	if err != nil {
-		errorf("parsing %s: %v", f.Name(), err)
-		return nil
+		return nil, err
 	}
 
 	var syms []Sym
@@ -34,10 +39,10 @@ func elfSymbols(f *os.File) []Sym {
 			sym.Code = 'B'
 		default:
 			i := int(s.Section)
-			if i < 0 || i >= len(p.Sections) {
+			if i < 0 || i >= len(f.elf.Sections) {
 				break
 			}
-			sect := p.Sections[i]
+			sect := f.elf.Sections[i]
 			switch sect.Flags & (elf.SHF_WRITE | elf.SHF_ALLOC | elf.SHF_EXECINSTR) {
 			case elf.SHF_ALLOC | elf.SHF_EXECINSTR:
 				sym.Code = 'T'
@@ -53,5 +58,22 @@ func elfSymbols(f *os.File) []Sym {
 		syms = append(syms, sym)
 	}
 
-	return syms
+	return syms, nil
+}
+
+func (f *elfFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	if sect := f.elf.Section(".text"); sect != nil {
+		textStart = sect.Addr
+	}
+	if sect := f.elf.Section(".gosymtab"); sect != nil {
+		if symtab, err = sect.Data(); err != nil {
+			return 0, nil, nil, err
+		}
+	}
+	if sect := f.elf.Section(".gopclntab"); sect != nil {
+		if pclntab, err = sect.Data(); err != nil {
+			return 0, nil, nil, err
+		}
+	}
+	return textStart, symtab, pclntab, nil
 }
diff --git a/src/cmd/nm/goobj.go b/src/cmd/internal/objfile/goobj.go
index b0de51db9..a4f49ebe4 100644
--- a/src/cmd/nm/goobj.go
+++ b/src/cmd/internal/objfile/goobj.go
@@ -4,7 +4,7 @@
 
 // Parsing of Go intermediate object files and archives.
 
-package main
+package objfile
 
 import (
 	"debug/goobj"
@@ -12,6 +12,18 @@ import (
 	"os"
 )
 
+type goobjFile struct {
+	goobj *goobj.Package
+}
+
+func openGoobj(r *os.File) (rawFile, error) {
+	f, err := goobj.Parse(r, `""`)
+	if err != nil {
+		return nil, err
+	}
+	return &goobjFile{f}, nil
+}
+
 func goobjName(id goobj.SymID) string {
 	if id.Version == 0 {
 		return id.Name
@@ -19,17 +31,11 @@ func goobjName(id goobj.SymID) string {
 	return fmt.Sprintf("%s<%d>", id.Name, id.Version)
 }
 
-func goobjSymbols(f *os.File) []Sym {
-	pkg, err := goobj.Parse(f, `""`)
-	if err != nil {
-		errorf("parsing %s: %v", f.Name(), err)
-		return nil
-	}
-
+func (f *goobjFile) symbols() ([]Sym, error) {
 	seen := make(map[goobj.SymID]bool)
 
 	var syms []Sym
-	for _, s := range pkg.Syms {
+	for _, s := range f.goobj.Syms {
 		seen[s.SymID] = true
 		sym := Sym{Addr: uint64(s.Data.Offset), Name: goobjName(s.SymID), Size: int64(s.Size), Type: s.Type.Name, Code: '?'}
 		switch s.Kind {
@@ -50,7 +56,7 @@ func goobjSymbols(f *os.File) []Sym {
 		syms = append(syms, sym)
 	}
 
-	for _, s := range pkg.Syms {
+	for _, s := range f.goobj.Syms {
 		for _, r := range s.Reloc {
 			if !seen[r.Sym] {
 				seen[r.Sym] = true
@@ -64,5 +70,12 @@ func goobjSymbols(f *os.File) []Sym {
 		}
 	}
 
-	return syms
+	return syms, nil
+}
+
+// pcln does not make sense for Go object files, because each
+// symbol has its own individual pcln table, so there is no global
+// space of addresses to map.
+func (f *goobjFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	return 0, nil, nil, fmt.Errorf("pcln not available in go object file")
 }
diff --git a/src/cmd/nm/macho.go b/src/cmd/internal/objfile/macho.go
index c60bde55b..f845792ff 100644
--- a/src/cmd/nm/macho.go
+++ b/src/cmd/internal/objfile/macho.go
@@ -4,36 +4,42 @@
 
 // Parsing of Mach-O executables (OS X).
 
-package main
+package objfile
 
 import (
 	"debug/macho"
+	"fmt"
 	"os"
 	"sort"
 )
 
-func machoSymbols(f *os.File) []Sym {
-	p, err := macho.NewFile(f)
+type machoFile struct {
+	macho *macho.File
+}
+
+func openMacho(r *os.File) (rawFile, error) {
+	f, err := macho.NewFile(r)
 	if err != nil {
-		errorf("parsing %s: %v", f.Name(), err)
-		return nil
+		return nil, err
 	}
+	return &machoFile{f}, nil
+}
 
-	if p.Symtab == nil {
-		errorf("%s: no symbol table", f.Name())
-		return nil
+func (f *machoFile) symbols() ([]Sym, error) {
+	if f.macho.Symtab == nil {
+		return nil, fmt.Errorf("missing symbol table")
 	}
 
 	// Build sorted list of addresses of all symbols.
 	// We infer the size of a symbol by looking at where the next symbol begins.
 	var addrs []uint64
-	for _, s := range p.Symtab.Syms {
+	for _, s := range f.macho.Symtab.Syms {
 		addrs = append(addrs, s.Value)
 	}
 	sort.Sort(uint64s(addrs))
 
 	var syms []Sym
-	for _, s := range p.Symtab.Syms {
+	for _, s := range f.macho.Symtab.Syms {
 		sym := Sym{Name: s.Name, Addr: s.Value, Code: '?'}
 		i := sort.Search(len(addrs), func(x int) bool { return addrs[x] > s.Value })
 		if i < len(addrs) {
@@ -41,8 +47,8 @@ func machoSymbols(f *os.File) []Sym {
 		}
 		if s.Sect == 0 {
 			sym.Code = 'U'
-		} else if int(s.Sect) <= len(p.Sections) {
-			sect := p.Sections[s.Sect-1]
+		} else if int(s.Sect) <= len(f.macho.Sections) {
+			sect := f.macho.Sections[s.Sect-1]
 			switch sect.Seg {
 			case "__TEXT":
 				sym.Code = 'R'
@@ -59,7 +65,24 @@ func machoSymbols(f *os.File) []Sym {
 		syms = append(syms, sym)
 	}
 
-	return syms
+	return syms, nil
+}
+
+func (f *machoFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	if sect := f.macho.Section("__text"); sect != nil {
+		textStart = sect.Addr
+	}
+	if sect := f.macho.Section("__gosymtab"); sect != nil {
+		if symtab, err = sect.Data(); err != nil {
+			return 0, nil, nil, err
+		}
+	}
+	if sect := f.macho.Section("__gopclntab"); sect != nil {
+		if pclntab, err = sect.Data(); err != nil {
+			return 0, nil, nil, err
+		}
+	}
+	return textStart, symtab, pclntab, nil
 }
 
 type uint64s []uint64
diff --git a/src/cmd/internal/objfile/objfile.go b/src/cmd/internal/objfile/objfile.go
new file mode 100644
index 000000000..09fa63e60
--- /dev/null
+++ b/src/cmd/internal/objfile/objfile.go
@@ -0,0 +1,72 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package objfile implements portable access to OS-specific executable files.
+package objfile
+
+import (
+	"debug/gosym"
+	"fmt"
+	"os"
+)
+
+type rawFile interface {
+	symbols() (syms []Sym, err error)
+	pcln() (textStart uint64, symtab, pclntab []byte, err error)
+}
+
+// A File is an opened executable file.
+type File struct {
+	r   *os.File
+	raw rawFile
+}
+
+// A Sym is a symbol defined in an executable file.
+type Sym struct {
+	Name string // symbol name
+	Addr uint64 // virtual address of symbol
+	Size int64  // size in bytes
+	Code rune   // nm code (T for text, D for data, and so on)
+	Type string // XXX?
+}
+
+var openers = []func(*os.File) (rawFile, error){
+	openElf,
+	openGoobj,
+	openMacho,
+	openPE,
+	openPlan9,
+}
+
+// Open opens the named file.
+// The caller must call f.Close when the file is no longer needed.
+func Open(name string) (*File, error) {
+	r, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	for _, try := range openers {
+		if raw, err := try(r); err == nil {
+			return &File{r, raw}, nil
+		}
+	}
+	r.Close()
+	return nil, fmt.Errorf("open %s: unrecognized object file", name)
+}
+
+func (f *File) Close() error {
+	return f.r.Close()
+}
+
+func (f *File) Symbols() ([]Sym, error) {
+	return f.raw.symbols()
+}
+
+func (f *File) PCLineTable() (*gosym.Table, error) {
+	textStart, symtab, pclntab, err := f.raw.pcln()
+	if err != nil {
+		return nil, err
+	}
+	return gosym.NewTable(symtab, gosym.NewLineTable(pclntab, textStart))
+}
diff --git a/src/cmd/internal/objfile/pe.go b/src/cmd/internal/objfile/pe.go
new file mode 100644
index 000000000..868709eaf
--- /dev/null
+++ b/src/cmd/internal/objfile/pe.go
@@ -0,0 +1,170 @@
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Parsing of PE executables (Microsoft Windows).
+
+package objfile
+
+import (
+	"debug/pe"
+	"fmt"
+	"os"
+	"sort"
+)
+
+type peFile struct {
+	pe *pe.File
+}
+
+func openPE(r *os.File) (rawFile, error) {
+	f, err := pe.NewFile(r)
+	if err != nil {
+		return nil, err
+	}
+	switch f.OptionalHeader.(type) {
+	case *pe.OptionalHeader32, *pe.OptionalHeader64:
+		// ok
+	default:
+		return nil, fmt.Errorf("unrecognized PE format")
+	}
+	return &peFile{f}, nil
+}
+
+func (f *peFile) symbols() ([]Sym, error) {
+	// Build sorted list of addresses of all symbols.
+	// We infer the size of a symbol by looking at where the next symbol begins.
+	var addrs []uint64
+
+	var imageBase uint64
+	switch oh := f.pe.OptionalHeader.(type) {
+	case *pe.OptionalHeader32:
+		imageBase = uint64(oh.ImageBase)
+	case *pe.OptionalHeader64:
+		imageBase = oh.ImageBase
+	}
+
+	var syms []Sym
+	for _, s := range f.pe.Symbols {
+		const (
+			N_UNDEF = 0  // An undefined (extern) symbol
+			N_ABS   = -1 // An absolute symbol (e_value is a constant, not an address)
+			N_DEBUG = -2 // A debugging symbol
+		)
+		sym := Sym{Name: s.Name, Addr: uint64(s.Value), Code: '?'}
+		switch s.SectionNumber {
+		case N_UNDEF:
+			sym.Code = 'U'
+		case N_ABS:
+			sym.Code = 'C'
+		case N_DEBUG:
+			sym.Code = '?'
+		default:
+			if s.SectionNumber < 0 || len(f.pe.Sections) < int(s.SectionNumber) {
+				return nil, fmt.Errorf("invalid section number in symbol table")
+			}
+			sect := f.pe.Sections[s.SectionNumber-1]
+			const (
+				text  = 0x20
+				data  = 0x40
+				bss   = 0x80
+				permX = 0x20000000
+				permR = 0x40000000
+				permW = 0x80000000
+			)
+			ch := sect.Characteristics
+			switch {
+			case ch&text != 0:
+				sym.Code = 'T'
+			case ch&data != 0:
+				if ch&permW == 0 {
+					sym.Code = 'R'
+				} else {
+					sym.Code = 'D'
+				}
+			case ch&bss != 0:
+				sym.Code = 'B'
+			}
+			sym.Addr += imageBase + uint64(sect.VirtualAddress)
+		}
+		syms = append(syms, sym)
+		addrs = append(addrs, sym.Addr)
+	}
+
+	sort.Sort(uint64s(addrs))
+	for i := range syms {
+		j := sort.Search(len(addrs), func(x int) bool { return addrs[x] > syms[i].Addr })
+		if j < len(addrs) {
+			syms[i].Size = int64(addrs[j] - syms[i].Addr)
+		}
+	}
+
+	return syms, nil
+}
+
+func (f *peFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	var imageBase uint64
+	switch oh := f.pe.OptionalHeader.(type) {
+	case *pe.OptionalHeader32:
+		imageBase = uint64(oh.ImageBase)
+	case *pe.OptionalHeader64:
+		imageBase = oh.ImageBase
+	default:
+		return 0, nil, nil, fmt.Errorf("pe file format not recognized")
+	}
+	if sect := f.pe.Section(".text"); sect != nil {
+		textStart = imageBase + uint64(sect.VirtualAddress)
+	}
+	if pclntab, err = loadPETable(f.pe, "runtime.pclntab", "runtime.epclntab"); err != nil {
+		// We didn't find the symbols, so look for the names used in 1.3 and earlier.
+		// TODO: Remove code looking for the old symbols when we no longer care about 1.3.
+		var err2 error
+		if pclntab, err2 = loadPETable(f.pe, "pclntab", "epclntab"); err2 != nil {
+			return 0, nil, nil, err
+		}
+	}
+	if symtab, err = loadPETable(f.pe, "runtime.symtab", "runtime.esymtab"); err != nil {
+		// Same as above.
+		var err2 error
+		if symtab, err2 = loadPETable(f.pe, "symtab", "esymtab"); err2 != nil {
+			return 0, nil, nil, err
+		}
+	}
+	return textStart, symtab, pclntab, nil
+}
+
+func findPESymbol(f *pe.File, name string) (*pe.Symbol, error) {
+	for _, s := range f.Symbols {
+		if s.Name != name {
+			continue
+		}
+		if s.SectionNumber <= 0 {
+			return nil, fmt.Errorf("symbol %s: invalid section number %d", name, s.SectionNumber)
+		}
+		if len(f.Sections) < int(s.SectionNumber) {
+			return nil, fmt.Errorf("symbol %s: section number %d is larger than max %d", name, s.SectionNumber, len(f.Sections))
+		}
+		return s, nil
+	}
+	return nil, fmt.Errorf("no %s symbol found", name)
+}
+
+func loadPETable(f *pe.File, sname, ename string) ([]byte, error) {
+	ssym, err := findPESymbol(f, sname)
+	if err != nil {
+		return nil, err
+	}
+	esym, err := findPESymbol(f, ename)
+	if err != nil {
+		return nil, err
+	}
+	if ssym.SectionNumber != esym.SectionNumber {
+		return nil, fmt.Errorf("%s and %s symbols must be in the same section", sname, ename)
+	}
+	sect := f.Sections[ssym.SectionNumber-1]
+	data, err := sect.Data()
+	if err != nil {
+		return nil, err
+	}
+	return data[ssym.Value:esym.Value], nil
+}
diff --git a/src/cmd/internal/objfile/plan9obj.go b/src/cmd/internal/objfile/plan9obj.go
new file mode 100644
index 000000000..80744f82a
--- /dev/null
+++ b/src/cmd/internal/objfile/plan9obj.go
@@ -0,0 +1,124 @@
+// Copyright 2014 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Parsing of Plan 9 a.out executables.
+
+package objfile
+
+import (
+	"debug/plan9obj"
+	"fmt"
+	"os"
+	"sort"
+)
+
+var validSymType = map[rune]bool{
+	'T': true,
+	't': true,
+	'D': true,
+	'd': true,
+	'B': true,
+	'b': true,
+}
+
+type plan9File struct {
+	plan9 *plan9obj.File
+}
+
+func openPlan9(r *os.File) (rawFile, error) {
+	f, err := plan9obj.NewFile(r)
+	if err != nil {
+		return nil, err
+	}
+	return &plan9File{f}, nil
+}
+
+func (f *plan9File) symbols() ([]Sym, error) {
+	plan9Syms, err := f.plan9.Symbols()
+	if err != nil {
+		return nil, err
+	}
+
+	// Build sorted list of addresses of all symbols.
+	// We infer the size of a symbol by looking at where the next symbol begins.
+	var addrs []uint64
+	for _, s := range plan9Syms {
+		if !validSymType[s.Type] {
+			continue
+		}
+		addrs = append(addrs, s.Value)
+	}
+	sort.Sort(uint64s(addrs))
+
+	var syms []Sym
+
+	for _, s := range plan9Syms {
+		if !validSymType[s.Type] {
+			continue
+		}
+		sym := Sym{Addr: s.Value, Name: s.Name, Code: rune(s.Type)}
+		i := sort.Search(len(addrs), func(x int) bool { return addrs[x] > s.Value })
+		if i < len(addrs) {
+			sym.Size = int64(addrs[i] - s.Value)
+		}
+		syms = append(syms, sym)
+	}
+
+	return syms, nil
+}
+
+func (f *plan9File) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	textStart = f.plan9.LoadAddress + f.plan9.HdrSize
+	if pclntab, err = loadPlan9Table(f.plan9, "runtime.pclntab", "runtime.epclntab"); err != nil {
+		// We didn't find the symbols, so look for the names used in 1.3 and earlier.
+		// TODO: Remove code looking for the old symbols when we no longer care about 1.3.
+		var err2 error
+		if pclntab, err2 = loadPlan9Table(f.plan9, "pclntab", "epclntab"); err2 != nil {
+			return 0, nil, nil, err
+		}
+	}
+	if symtab, err = loadPlan9Table(f.plan9, "runtime.symtab", "runtime.esymtab"); err != nil {
+		// Same as above.
+		var err2 error
+		if symtab, err2 = loadPlan9Table(f.plan9, "symtab", "esymtab"); err2 != nil {
+			return 0, nil, nil, err
+		}
+	}
+	return textStart, symtab, pclntab, nil
+}
+
+func findPlan9Symbol(f *plan9obj.File, name string) (*plan9obj.Sym, error) {
+	syms, err := f.Symbols()
+	if err != nil {
+		return nil, err
+	}
+	for _, s := range syms {
+		if s.Name != name {
+			continue
+		}
+		return &s, nil
+	}
+	return nil, fmt.Errorf("no %s symbol found", name)
+}
+
+func loadPlan9Table(f *plan9obj.File, sname, ename string) ([]byte, error) {
+	ssym, err := findPlan9Symbol(f, sname)
+	if err != nil {
+		return nil, err
+	}
+	esym, err := findPlan9Symbol(f, ename)
+	if err != nil {
+		return nil, err
+	}
+	sect := f.Section("text")
+	if sect == nil {
+		return nil, err
+	}
+	data, err := sect.Data()
+	if err != nil {
+		return nil, err
+	}
+	textStart := f.LoadAddress + f.HdrSize
+	return data[ssym.Value-textStart : esym.Value-textStart], nil
+}
diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c
index 702f559a8..7bf18f081 100644
--- a/src/cmd/ld/data.c
+++ b/src/cmd/ld/data.c
@@ -145,7 +145,7 @@ relocsym(LSym *s)
 			diag("%s: invalid relocation %d+%d not in [%d,%d)", s->name, off, siz, 0, s->np);
 			continue;
 		}
-		if(r->sym != S && (r->sym->type & SMASK == 0 || r->sym->type & SMASK == SXREF)) {
+		if(r->sym != S && ((r->sym->type & (SMASK | SHIDDEN)) == 0 || (r->sym->type & SMASK) == SXREF)) {
 			diag("%s: not defined", r->sym->name);
 			continue;
 		}
@@ -281,9 +281,13 @@ relocsym(LSym *s)
 					if(thechar == '6')
 						o = 0;
 				} else if(HEADTYPE == Hdarwin) {
-					if(rs->type != SHOSTOBJ)
-						o += symaddr(rs) - rs->sect->vaddr;
-					o -= r->off; // WTF?
+					if(r->type == R_CALL) {
+						if(rs->type != SHOSTOBJ)
+							o += symaddr(rs) - rs->sect->vaddr;
+						o -= r->off; // relative to section offset, not symbol
+					} else {
+						o += r->siz;
+					}
 				} else {
 					diag("unhandled pcrel relocation for %s", headstring);
 				}
@@ -425,10 +429,10 @@ dynreloc(void)
 }
 
 static void
-blk(LSym *start, int32 addr, int32 size)
+blk(LSym *start, int64 addr, int64 size)
 {
 	LSym *sym;
-	int32 eaddr;
+	int64 eaddr;
 	uchar *p, *ep;
 
 	for(sym = start; sym != nil; sym = sym->next)
@@ -469,10 +473,10 @@ blk(LSym *start, int32 addr, int32 size)
 }
 
 void
-codeblk(int32 addr, int32 size)
+codeblk(int64 addr, int64 size)
 {
 	LSym *sym;
-	int32 eaddr, n;
+	int64 eaddr, n;
 	uchar *q;
 
 	if(debug['a'])
@@ -529,10 +533,10 @@ codeblk(int32 addr, int32 size)
 }
 
 void
-datblk(int32 addr, int32 size)
+datblk(int64 addr, int64 size)
 {
 	LSym *sym;
-	int32 i, eaddr;
+	int64 i, eaddr;
 	uchar *p, *ep;
 	char *typ, *rsname;
 	Reloc *r;
@@ -985,8 +989,8 @@ dodata(void)
 	sect->align = maxalign(s, SINITARR-1);
 	datsize = rnd(datsize, sect->align);
 	sect->vaddr = datsize;
-	linklookup(ctxt, "noptrdata", 0)->sect = sect;
-	linklookup(ctxt, "enoptrdata", 0)->sect = sect;
+	linklookup(ctxt, "runtime.noptrdata", 0)->sect = sect;
+	linklookup(ctxt, "runtime.enoptrdata", 0)->sect = sect;
 	for(; s != nil && s->type < SINITARR; s = s->next) {
 		datsize = aligndatsize(datsize, s);
 		s->sect = sect;
@@ -1016,9 +1020,9 @@ dodata(void)
 	sect->align = maxalign(s, SBSS-1);
 	datsize = rnd(datsize, sect->align);
 	sect->vaddr = datsize;
-	linklookup(ctxt, "data", 0)->sect = sect;
-	linklookup(ctxt, "edata", 0)->sect = sect;
-	gcdata = linklookup(ctxt, "gcdata", 0);
+	linklookup(ctxt, "runtime.data", 0)->sect = sect;
+	linklookup(ctxt, "runtime.edata", 0)->sect = sect;
+	gcdata = linklookup(ctxt, "runtime.gcdata", 0);
 	proggeninit(&gen, gcdata);
 	for(; s != nil && s->type < SBSS; s = s->next) {
 		if(s->type == SINITARR) {
@@ -1040,9 +1044,9 @@ dodata(void)
 	sect->align = maxalign(s, SNOPTRBSS-1);
 	datsize = rnd(datsize, sect->align);
 	sect->vaddr = datsize;
-	linklookup(ctxt, "bss", 0)->sect = sect;
-	linklookup(ctxt, "ebss", 0)->sect = sect;
-	gcbss = linklookup(ctxt, "gcbss", 0);
+	linklookup(ctxt, "runtime.bss", 0)->sect = sect;
+	linklookup(ctxt, "runtime.ebss", 0)->sect = sect;
+	gcbss = linklookup(ctxt, "runtime.gcbss", 0);
 	proggeninit(&gen, gcbss);
 	for(; s != nil && s->type < SNOPTRBSS; s = s->next) {
 		s->sect = sect;
@@ -1059,8 +1063,8 @@ dodata(void)
 	sect->align = maxalign(s, SNOPTRBSS);
 	datsize = rnd(datsize, sect->align);
 	sect->vaddr = datsize;
-	linklookup(ctxt, "noptrbss", 0)->sect = sect;
-	linklookup(ctxt, "enoptrbss", 0)->sect = sect;
+	linklookup(ctxt, "runtime.noptrbss", 0)->sect = sect;
+	linklookup(ctxt, "runtime.enoptrbss", 0)->sect = sect;
 	for(; s != nil && s->type == SNOPTRBSS; s = s->next) {
 		datsize = aligndatsize(datsize, s);
 		s->sect = sect;
@@ -1068,7 +1072,7 @@ dodata(void)
 		growdatsize(&datsize, s);
 	}
 	sect->len = datsize - sect->vaddr;
-	linklookup(ctxt, "end", 0)->sect = sect;
+	linklookup(ctxt, "runtime.end", 0)->sect = sect;
 
 	// 6g uses 4-byte relocation offsets, so the entire segment must fit in 32 bits.
 	if(datsize != (uint32)datsize) {
@@ -1139,8 +1143,8 @@ dodata(void)
 	sect->align = maxalign(s, STYPELINK-1);
 	datsize = rnd(datsize, sect->align);
 	sect->vaddr = 0;
-	linklookup(ctxt, "rodata", 0)->sect = sect;
-	linklookup(ctxt, "erodata", 0)->sect = sect;
+	linklookup(ctxt, "runtime.rodata", 0)->sect = sect;
+	linklookup(ctxt, "runtime.erodata", 0)->sect = sect;
 	for(; s != nil && s->type < STYPELINK; s = s->next) {
 		datsize = aligndatsize(datsize, s);
 		s->sect = sect;
@@ -1155,8 +1159,8 @@ dodata(void)
 	sect->align = maxalign(s, STYPELINK);
 	datsize = rnd(datsize, sect->align);
 	sect->vaddr = datsize;
-	linklookup(ctxt, "typelink", 0)->sect = sect;
-	linklookup(ctxt, "etypelink", 0)->sect = sect;
+	linklookup(ctxt, "runtime.typelink", 0)->sect = sect;
+	linklookup(ctxt, "runtime.etypelink", 0)->sect = sect;
 	for(; s != nil && s->type == STYPELINK; s = s->next) {
 		datsize = aligndatsize(datsize, s);
 		s->sect = sect;
@@ -1171,8 +1175,8 @@ dodata(void)
 	sect->align = maxalign(s, SPCLNTAB-1);
 	datsize = rnd(datsize, sect->align);
 	sect->vaddr = datsize;
-	linklookup(ctxt, "symtab", 0)->sect = sect;
-	linklookup(ctxt, "esymtab", 0)->sect = sect;
+	linklookup(ctxt, "runtime.symtab", 0)->sect = sect;
+	linklookup(ctxt, "runtime.esymtab", 0)->sect = sect;
 	for(; s != nil && s->type < SPCLNTAB; s = s->next) {
 		datsize = aligndatsize(datsize, s);
 		s->sect = sect;
@@ -1187,8 +1191,8 @@ dodata(void)
 	sect->align = maxalign(s, SELFROSECT-1);
 	datsize = rnd(datsize, sect->align);
 	sect->vaddr = datsize;
-	linklookup(ctxt, "pclntab", 0)->sect = sect;
-	linklookup(ctxt, "epclntab", 0)->sect = sect;
+	linklookup(ctxt, "runtime.pclntab", 0)->sect = sect;
+	linklookup(ctxt, "runtime.epclntab", 0)->sect = sect;
 	for(; s != nil && s->type < SELFROSECT; s = s->next) {
 		datsize = aligndatsize(datsize, s);
 		s->sect = sect;
@@ -1241,8 +1245,8 @@ textaddress(void)
 	// and then letting threads copy down, but probably not worth it.
 	sect = segtext.sect;
 	sect->align = funcalign;
-	linklookup(ctxt, "text", 0)->sect = sect;
-	linklookup(ctxt, "etext", 0)->sect = sect;
+	linklookup(ctxt, "runtime.text", 0)->sect = sect;
+	linklookup(ctxt, "runtime.etext", 0)->sect = sect;
 	va = INITTEXT;
 	sect->vaddr = va;
 	for(sym = ctxt->textp; sym != nil; sym = sym->next) {
@@ -1353,32 +1357,32 @@ address(void)
 			sub->value += sym->value;
 	}
 
-	xdefine("text", STEXT, text->vaddr);
-	xdefine("etext", STEXT, text->vaddr + text->len);
-	xdefine("rodata", SRODATA, rodata->vaddr);
-	xdefine("erodata", SRODATA, rodata->vaddr + rodata->len);
-	xdefine("typelink", SRODATA, typelink->vaddr);
-	xdefine("etypelink", SRODATA, typelink->vaddr + typelink->len);
-
-	sym = linklookup(ctxt, "gcdata", 0);
-	xdefine("egcdata", SRODATA, symaddr(sym) + sym->size);
-	linklookup(ctxt, "egcdata", 0)->sect = sym->sect;
-
-	sym = linklookup(ctxt, "gcbss", 0);
-	xdefine("egcbss", SRODATA, symaddr(sym) + sym->size);
-	linklookup(ctxt, "egcbss", 0)->sect = sym->sect;
-
-	xdefine("symtab", SRODATA, symtab->vaddr);
-	xdefine("esymtab", SRODATA, symtab->vaddr + symtab->len);
-	xdefine("pclntab", SRODATA, pclntab->vaddr);
-	xdefine("epclntab", SRODATA, pclntab->vaddr + pclntab->len);
-	xdefine("noptrdata", SNOPTRDATA, noptr->vaddr);
-	xdefine("enoptrdata", SNOPTRDATA, noptr->vaddr + noptr->len);
-	xdefine("bss", SBSS, bss->vaddr);
-	xdefine("ebss", SBSS, bss->vaddr + bss->len);
-	xdefine("data", SDATA, data->vaddr);
-	xdefine("edata", SDATA, data->vaddr + data->len);
-	xdefine("noptrbss", SNOPTRBSS, noptrbss->vaddr);
-	xdefine("enoptrbss", SNOPTRBSS, noptrbss->vaddr + noptrbss->len);
-	xdefine("end", SBSS, segdata.vaddr + segdata.len);
+	xdefine("runtime.text", STEXT, text->vaddr);
+	xdefine("runtime.etext", STEXT, text->vaddr + text->len);
+	xdefine("runtime.rodata", SRODATA, rodata->vaddr);
+	xdefine("runtime.erodata", SRODATA, rodata->vaddr + rodata->len);
+	xdefine("runtime.typelink", SRODATA, typelink->vaddr);
+	xdefine("runtime.etypelink", SRODATA, typelink->vaddr + typelink->len);
+
+	sym = linklookup(ctxt, "runtime.gcdata", 0);
+	xdefine("runtime.egcdata", SRODATA, symaddr(sym) + sym->size);
+	linklookup(ctxt, "runtime.egcdata", 0)->sect = sym->sect;
+
+	sym = linklookup(ctxt, "runtime.gcbss", 0);
+	xdefine("runtime.egcbss", SRODATA, symaddr(sym) + sym->size);
+	linklookup(ctxt, "runtime.egcbss", 0)->sect = sym->sect;
+
+	xdefine("runtime.symtab", SRODATA, symtab->vaddr);
+	xdefine("runtime.esymtab", SRODATA, symtab->vaddr + symtab->len);
+	xdefine("runtime.pclntab", SRODATA, pclntab->vaddr);
+	xdefine("runtime.epclntab", SRODATA, pclntab->vaddr + pclntab->len);
+	xdefine("runtime.noptrdata", SNOPTRDATA, noptr->vaddr);
+	xdefine("runtime.enoptrdata", SNOPTRDATA, noptr->vaddr + noptr->len);
+	xdefine("runtime.bss", SBSS, bss->vaddr);
+	xdefine("runtime.ebss", SBSS, bss->vaddr + bss->len);
+	xdefine("runtime.data", SDATA, data->vaddr);
+	xdefine("runtime.edata", SDATA, data->vaddr + data->len);
+	xdefine("runtime.noptrbss", SNOPTRBSS, noptrbss->vaddr);
+	xdefine("runtime.enoptrbss", SNOPTRBSS, noptrbss->vaddr + noptrbss->len);
+	xdefine("runtime.end", SBSS, segdata.vaddr + segdata.len);
 }
diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index 5db41f9a7..7b997464d 100644
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -1351,10 +1351,10 @@ genasmsym(void (*put)(LSym*, char*, int, vlong, vlong, int, LSym*))
 
 	// These symbols won't show up in the first loop below because we
 	// skip STEXT symbols. Normal STEXT symbols are emitted by walking textp.
-	s = linklookup(ctxt, "text", 0);
+	s = linklookup(ctxt, "runtime.text", 0);
 	if(s->type == STEXT)
 		put(s, s->name, 'T', s->value, s->size, s->version, 0);
-	s = linklookup(ctxt, "etext", 0);
+	s = linklookup(ctxt, "runtime.etext", 0);
 	if(s->type == STEXT)
 		put(s, s->name, 'T', s->value, s->size, s->version, 0);
 
@@ -1556,3 +1556,56 @@ diag(char *fmt, ...)
 		errorexit();
 	}
 }
+
+void
+checkgo(void)
+{
+	LSym *s;
+	Reloc *r;
+	int i;
+	int changed;
+	
+	if(!debug['C'])
+		return;
+	
+	// TODO(rsc,khr): Eventually we want to get to no Go-called C functions at all,
+	// which would simplify this logic quite a bit.
+
+	// Mark every Go-called C function with cfunc=2, recursively.
+	do {
+		changed = 0;
+		for(s = ctxt->textp; s != nil; s = s->next) {
+			if(s->cfunc == 0 || (s->cfunc == 2 && s->nosplit)) {
+				for(i=0; i<s->nr; i++) {
+					r = &s->r[i];
+					if(r->sym == nil)
+						continue;
+					if((r->type == R_CALL || r->type == R_CALLARM) && r->sym->type == STEXT) {
+						if(r->sym->cfunc == 1) {
+							changed = 1;
+							r->sym->cfunc = 2;
+						}
+					}
+				}
+			}
+		}
+	}while(changed);
+
+	// Complain about Go-called C functions that can split the stack
+	// (that can be preempted for garbage collection or trigger a stack copy).
+	for(s = ctxt->textp; s != nil; s = s->next) {
+		if(s->cfunc == 0 || (s->cfunc == 2 && s->nosplit)) {
+			for(i=0; i<s->nr; i++) {
+				r = &s->r[i];
+				if(r->sym == nil)
+					continue;
+				if((r->type == R_CALL || r->type == R_CALLARM) && r->sym->type == STEXT) {
+					if(s->cfunc == 0 && r->sym->cfunc == 2 && !r->sym->nosplit)
+						print("Go %s calls C %s\n", s->name, r->sym->name);
+					else if(s->cfunc == 2 && s->nosplit && !r->sym->nosplit)
+						print("Go calls C %s calls %s\n", s->name, r->sym->name);
+				}
+			}
+		}
+	}
+}
diff --git a/src/cmd/ld/lib.h b/src/cmd/ld/lib.h
index 4094dfa6b..067ffa0bc 100644
--- a/src/cmd/ld/lib.h
+++ b/src/cmd/ld/lib.h
@@ -183,12 +183,13 @@ uint16	be16(uchar *b);
 uint32	be32(uchar *b);
 uint64	be64(uchar *b);
 void	callgraph(void);
+void	checkgo(void);
 void	cflush(void);
-void	codeblk(int32 addr, int32 size);
+void	codeblk(int64 addr, int64 size);
 vlong	cpos(void);
 void	cseek(vlong p);
 void	cwrite(void *buf, int n);
-void	datblk(int32 addr, int32 size);
+void	datblk(int64 addr, int64 size);
 int	datcmp(LSym *s1, LSym *s2);
 vlong	datoff(vlong addr);
 void	deadcode(void);
diff --git a/src/cmd/ld/pcln.c b/src/cmd/ld/pcln.c
index 4c2ffa78e..3cd9e65da 100644
--- a/src/cmd/ld/pcln.c
+++ b/src/cmd/ld/pcln.c
@@ -90,7 +90,7 @@ renumberfiles(Link *ctxt, LSym **files, int nfiles, Pcdata *d)
 		}
 		dv = val - newval;
 		newval = val;
-		v = (uint32)(dv<<1) ^ (uint32)(int32)(dv>>31);
+		v = ((uint32)dv<<1) ^ (uint32)(int32)(dv>>31);
 		addvarint(&out, v);
 
 		// pc delta
@@ -119,7 +119,7 @@ pclntab(void)
 	static Pcln zpcln;
 	
 	funcdata_bytes = 0;
-	ftab = linklookup(ctxt, "pclntab", 0);
+	ftab = linklookup(ctxt, "runtime.pclntab", 0);
 	ftab->type = SPCLNTAB;
 	ftab->reachable = 1;
 
diff --git a/src/cmd/ld/pobj.c b/src/cmd/ld/pobj.c
index d78dacd36..54c5ef247 100644
--- a/src/cmd/ld/pobj.c
+++ b/src/cmd/ld/pobj.c
@@ -71,6 +71,7 @@ main(int argc, char *argv[])
 	if(thechar == '6')
 		flagcount("8", "assume 64-bit addresses", &debug['8']);
 	flagfn1("B", "info: define ELF NT_GNU_BUILD_ID note", addbuildinfo);
+	flagcount("C", "check Go calls to C code", &debug['C']);
 	flagint64("D", "addr: data address", &INITDAT);
 	flagstr("E", "sym: entry symbol", &INITENTRY);
 	if(thechar == '5')
@@ -162,6 +163,7 @@ main(int argc, char *argv[])
 		mark(linklookup(ctxt, "runtime.read_tls_fallback", 0));
 	}
 
+	checkgo();
 	deadcode();
 	callgraph();
 	paramspace = "SP";	/* (FP) now (SP) on output */
diff --git a/src/cmd/ld/symtab.c b/src/cmd/ld/symtab.c
index 8149a6716..c3a72c3cf 100644
--- a/src/cmd/ld/symtab.c
+++ b/src/cmd/ld/symtab.c
@@ -347,36 +347,36 @@ symtab(void)
 
 	// Define these so that they'll get put into the symbol table.
 	// data.c:/^address will provide the actual values.
-	xdefine("text", STEXT, 0);
-	xdefine("etext", STEXT, 0);
-	xdefine("typelink", SRODATA, 0);
-	xdefine("etypelink", SRODATA, 0);
-	xdefine("rodata", SRODATA, 0);
-	xdefine("erodata", SRODATA, 0);
-	xdefine("noptrdata", SNOPTRDATA, 0);
-	xdefine("enoptrdata", SNOPTRDATA, 0);
-	xdefine("data", SDATA, 0);
-	xdefine("edata", SDATA, 0);
-	xdefine("bss", SBSS, 0);
-	xdefine("ebss", SBSS, 0);
-	xdefine("noptrbss", SNOPTRBSS, 0);
-	xdefine("enoptrbss", SNOPTRBSS, 0);
-	xdefine("end", SBSS, 0);
-	xdefine("epclntab", SRODATA, 0);
-	xdefine("esymtab", SRODATA, 0);
+	xdefine("runtime.text", STEXT, 0);
+	xdefine("runtime.etext", STEXT, 0);
+	xdefine("runtime.typelink", SRODATA, 0);
+	xdefine("runtime.etypelink", SRODATA, 0);
+	xdefine("runtime.rodata", SRODATA, 0);
+	xdefine("runtime.erodata", SRODATA, 0);
+	xdefine("runtime.noptrdata", SNOPTRDATA, 0);
+	xdefine("runtime.enoptrdata", SNOPTRDATA, 0);
+	xdefine("runtime.data", SDATA, 0);
+	xdefine("runtime.edata", SDATA, 0);
+	xdefine("runtime.bss", SBSS, 0);
+	xdefine("runtime.ebss", SBSS, 0);
+	xdefine("runtime.noptrbss", SNOPTRBSS, 0);
+	xdefine("runtime.enoptrbss", SNOPTRBSS, 0);
+	xdefine("runtime.end", SBSS, 0);
+	xdefine("runtime.epclntab", SRODATA, 0);
+	xdefine("runtime.esymtab", SRODATA, 0);
 
 	// garbage collection symbols
-	s = linklookup(ctxt, "gcdata", 0);
+	s = linklookup(ctxt, "runtime.gcdata", 0);
 	s->type = SRODATA;
 	s->size = 0;
 	s->reachable = 1;
-	xdefine("egcdata", SRODATA, 0);
+	xdefine("runtime.egcdata", SRODATA, 0);
 
-	s = linklookup(ctxt, "gcbss", 0);
+	s = linklookup(ctxt, "runtime.gcbss", 0);
 	s->type = SRODATA;
 	s->size = 0;
 	s->reachable = 1;
-	xdefine("egcbss", SRODATA, 0);
+	xdefine("runtime.egcbss", SRODATA, 0);
 
 	// pseudo-symbols to mark locations of type, string, and go string data.
 	s = linklookup(ctxt, "type.*", 0);
@@ -397,9 +397,9 @@ symtab(void)
 	s->reachable = 1;
 	symgofunc = s;
 	
-	symtypelink = linklookup(ctxt, "typelink", 0);
+	symtypelink = linklookup(ctxt, "runtime.typelink", 0);
 
-	symt = linklookup(ctxt, "symtab", 0);
+	symt = linklookup(ctxt, "runtime.symtab", 0);
 	symt->type = SSYMTAB;
 	symt->size = 0;
 	symt->reachable = 1;
diff --git a/src/cmd/link/auto.go b/src/cmd/link/auto.go
index 8f0c39f8c..f9228e8ca 100644
--- a/src/cmd/link/auto.go
+++ b/src/cmd/link/auto.go
@@ -18,26 +18,26 @@ import (
 // linkerDefined lists the symbols supplied by other parts of the linker
 // (runtime.go and layout.go).
 var linkerDefined = map[string]bool{
-	"bss":        true,
-	"data":       true,
-	"ebss":       true,
-	"edata":      true,
-	"efunctab":   true,
-	"end":        true,
-	"enoptrbss":  true,
-	"enoptrdata": true,
-	"erodata":    true,
-	"etext":      true,
-	"etypelink":  true,
-	"functab":    true,
-	"gcbss":      true,
-	"gcdata":     true,
-	"noptrbss":   true,
-	"noptrdata":  true,
-	"pclntab":    true,
-	"rodata":     true,
-	"text":       true,
-	"typelink":   true,
+	"runtime.bss":        true,
+	"runtime.data":       true,
+	"runtime.ebss":       true,
+	"runtime.edata":      true,
+	"runtime.efunctab":   true,
+	"runtime.end":        true,
+	"runtime.enoptrbss":  true,
+	"runtime.enoptrdata": true,
+	"runtime.erodata":    true,
+	"runtime.etext":      true,
+	"runtime.etypelink":  true,
+	"runtime.functab":    true,
+	"runtime.gcbss":      true,
+	"runtime.gcdata":     true,
+	"runtime.noptrbss":   true,
+	"runtime.noptrdata":  true,
+	"runtime.pclntab":    true,
+	"runtime.rodata":     true,
+	"runtime.text":       true,
+	"runtime.typelink":   true,
 }
 
 // isAuto reports whether sym is an automatically-generated data or constant symbol.
diff --git a/src/cmd/link/layout.go b/src/cmd/link/layout.go
index 647702244..149ebced0 100644
--- a/src/cmd/link/layout.go
+++ b/src/cmd/link/layout.go
@@ -172,9 +172,9 @@ func (p *Prog) layout() {
 			start = sect.VirtAddr
 			end = sect.VirtAddr + sect.Size
 		}
-		p.defineConst(name, start)
-		p.defineConst("e"+name, end)
+		p.defineConst("runtime."+name, start)
+		p.defineConst("runtime.e"+name, end)
 		progEnd = end
 	}
-	p.defineConst("end", progEnd)
+	p.defineConst("runtime.end", progEnd)
 }
diff --git a/src/cmd/link/pclntab.go b/src/cmd/link/pclntab.go
index b0b19ad53..232d586bf 100644
--- a/src/cmd/link/pclntab.go
+++ b/src/cmd/link/pclntab.go
@@ -183,7 +183,7 @@ func (p *Prog) pclntab() {
 
 	pclntab := &Sym{
 		Sym: &goobj.Sym{
-			SymID: goobj.SymID{Name: "pclntab"},
+			SymID: goobj.SymID{Name: "runtime.pclntab"},
 			Kind:  goobj.SPCLNTAB,
 			Size:  buf.Size(),
 			Reloc: buf.Reloc(),
@@ -437,7 +437,7 @@ func (it *PCIter) Next() {
 		return
 	}
 	it.start = false
-	sv := int32(uv)>>1 ^ int32(uv)<<31>>31
+	sv := int32(uv>>1) ^ int32(uv<<31)>>31
 	it.Value += sv
 
 	// pc delta
diff --git a/src/cmd/link/pclntab_test.go b/src/cmd/link/pclntab_test.go
index 5696a0978..19953f579 100644
--- a/src/cmd/link/pclntab_test.go
+++ b/src/cmd/link/pclntab_test.go
@@ -141,7 +141,7 @@ func TestPclntab(t *testing.T) {
 // It returns a symbol reader for pclntab, the offset of the function information
 // within that symbol, and the args and frame values read out of the information.
 func findFunc(t *testing.T, p *Prog, name string) (r *SymReader, off, args, frame int, ok bool) {
-	tabsym := p.Syms[goobj.SymID{Name: "pclntab"}]
+	tabsym := p.Syms[goobj.SymID{Name: "runtime.pclntab"}]
 	if tabsym == nil {
 		t.Errorf("pclntab is missing in binary")
 		return
@@ -276,6 +276,12 @@ func checkPCData(t *testing.T, r *SymReader, name string, off, pc, pnum, val int
 // readPCData reads the PCData table offset off
 // to obtain and return the value associated with pc.
 func readPCData(t *testing.T, r *SymReader, name, pcdataname string, pcoff uint32, pc int) (int, bool) {
+	// "If pcsp, pcfile, pcln, or any of the pcdata offsets is zero,
+	// that table is considered missing, and all PCs take value -1."
+	if pcoff == 0 {
+		return -1, true
+	}
+
 	var it PCIter
 	for it.Init(r.p, r.data[pcoff:]); !it.Done; it.Next() {
 		if it.PC <= uint32(pc) && uint32(pc) < it.NextPC {
diff --git a/src/cmd/link/runtime.go b/src/cmd/link/runtime.go
index 5d37015eb..b0c1ac98a 100644
--- a/src/cmd/link/runtime.go
+++ b/src/cmd/link/runtime.go
@@ -15,13 +15,13 @@ func (p *Prog) runtime() {
 	// TODO: Implement garbage collection data.
 	p.addSym(&Sym{
 		Sym: &goobj.Sym{
-			SymID: goobj.SymID{Name: "gcdata"},
+			SymID: goobj.SymID{Name: "runtime.gcdata"},
 			Kind:  goobj.SRODATA,
 		},
 	})
 	p.addSym(&Sym{
 		Sym: &goobj.Sym{
-			SymID: goobj.SymID{Name: "gcbss"},
+			SymID: goobj.SymID{Name: "runtime.gcbss"},
 			Kind:  goobj.SRODATA,
 		},
 	})
diff --git a/src/cmd/link/testdata/Makefile b/src/cmd/link/testdata/Makefile
index 3b1b15f73..e9651a03f 100644
--- a/src/cmd/link/testdata/Makefile
+++ b/src/cmd/link/testdata/Makefile
@@ -9,7 +9,7 @@ ALL=\
 all: $(ALL)
 
 %.6: %.s
-	go tool 6a $*.s
+	GOARCH=amd64 GOOS=darwin go tool 6a -trimpath=$(shell pwd) $*.s
 
 pclntab.s: genpcln.go
 	go run genpcln.go >pclntab.s
diff --git a/src/cmd/link/testdata/autosection.6 b/src/cmd/link/testdata/autosection.6
index bc9d446e1..386f422cf 100644
--- a/src/cmd/link/testdata/autosection.6
+++ b/src/cmd/link/testdata/autosection.6
diff --git a/src/cmd/link/testdata/autosection.s b/src/cmd/link/testdata/autosection.s
index 8a579b702..e0cb21723 100644
--- a/src/cmd/link/testdata/autosection.s
+++ b/src/cmd/link/testdata/autosection.s
@@ -4,7 +4,7 @@
 
 // Test of section-named symbols.
 
-#include "../../ld/textflag.h"
+#include "textflag.h"
 
 TEXT start(SB),7,$0
 	MOVQ $autotab(SB),AX
@@ -16,37 +16,37 @@ GLOBL zero(SB), $8
 GLOBL zeronoptr(SB), NOPTR, $16
 
 // text
-DATA autotab+0x00(SB)/8, $text(SB)
+DATA autotab+0x00(SB)/8, $runtime·text(SB)
 DATA autotab+0x08(SB)/8, $start(SB)
-DATA autotab+0x10(SB)/8, $etext(SB)
+DATA autotab+0x10(SB)/8, $runtime·etext(SB)
 DATA autotab+0x18(SB)/8, $start+16(SB)
 
 // data
-DATA autotab+0x20(SB)/8, $data(SB)
+DATA autotab+0x20(SB)/8, $runtime·data(SB)
 DATA autotab+0x28(SB)/8, $autotab(SB)
-DATA autotab+0x30(SB)/8, $edata(SB)
+DATA autotab+0x30(SB)/8, $runtime·edata(SB)
 DATA autotab+0x38(SB)/8, $nonzero+4(SB)
 
 // bss
-DATA autotab+0x40(SB)/8, $bss(SB)
+DATA autotab+0x40(SB)/8, $runtime·bss(SB)
 DATA autotab+0x48(SB)/8, $zero(SB)
-DATA autotab+0x50(SB)/8, $ebss(SB)
+DATA autotab+0x50(SB)/8, $runtime·ebss(SB)
 DATA autotab+0x58(SB)/8, $zero+8(SB)
 
 // noptrdata
-DATA autotab+0x60(SB)/8, $noptrdata(SB)
+DATA autotab+0x60(SB)/8, $runtime·noptrdata(SB)
 DATA autotab+0x68(SB)/8, $nonzeronoptr(SB)
-DATA autotab+0x70(SB)/8, $enoptrdata(SB)
+DATA autotab+0x70(SB)/8, $runtime·enoptrdata(SB)
 DATA autotab+0x78(SB)/8, $nonzeronoptr+8(SB)
 
 // noptrbss
-DATA autotab+0x80(SB)/8, $noptrbss(SB)
+DATA autotab+0x80(SB)/8, $runtime·noptrbss(SB)
 DATA autotab+0x88(SB)/8, $zeronoptr(SB)
-DATA autotab+0x90(SB)/8, $enoptrbss(SB)
+DATA autotab+0x90(SB)/8, $runtime·enoptrbss(SB)
 DATA autotab+0x98(SB)/8, $zeronoptr+16(SB)
 
 // end
-DATA autotab+0xa0(SB)/8, $end(SB)
+DATA autotab+0xa0(SB)/8, $runtime·end(SB)
 DATA autotab+0xa8(SB)/8, $zeronoptr+16(SB)
 
 GLOBL autotab(SB), $0xb0
diff --git a/src/cmd/link/testdata/autoweak.6 b/src/cmd/link/testdata/autoweak.6
index 636a4d844..5d74d4e2b 100644
--- a/src/cmd/link/testdata/autoweak.6
+++ b/src/cmd/link/testdata/autoweak.6
diff --git a/src/cmd/link/testdata/dead.6 b/src/cmd/link/testdata/dead.6
index bb77aafe8..9540adc1a 100644
--- a/src/cmd/link/testdata/dead.6
+++ b/src/cmd/link/testdata/dead.6
diff --git a/src/cmd/link/testdata/dead.s b/src/cmd/link/testdata/dead.s
index 832ddaff6..86f31360f 100644
--- a/src/cmd/link/testdata/dead.s
+++ b/src/cmd/link/testdata/dead.s
@@ -17,7 +17,7 @@ TEXT text1(SB),7,$0
 	RET
 
 TEXT text2(SB),7,$0
-	MOVQ $edata(SB),BX
+	MOVQ $runtime·edata(SB),BX
 	RET
 
 DATA data1<>+0(SB)/8, $data2(SB)
@@ -46,4 +46,3 @@ GLOBL dead_data1(SB), $16
 GLOBL dead_data2(SB), $1
 GLOBL dead_data3(SB), $1
 GLOBL dead_funcdata(SB), $8
-
diff --git a/src/cmd/link/testdata/genpcln.go b/src/cmd/link/testdata/genpcln.go
index 684cc07a2..c10eaeae9 100644
--- a/src/cmd/link/testdata/genpcln.go
+++ b/src/cmd/link/testdata/genpcln.go
@@ -107,6 +107,6 @@ func main() {
 	for f := 0; f < 3; f++ {
 		fmt.Printf("\tCALL func%d(SB)\n", f)
 	}
-	fmt.Printf("\tMOVQ $pclntab(SB), AX\n")
+	fmt.Printf("\tMOVQ $runtime·pclntab(SB), AX\n")
 	fmt.Printf("\n\tRET\n")
 }
diff --git a/src/cmd/link/testdata/hello.6 b/src/cmd/link/testdata/hello.6
index b129dc029..67983f1a9 100644
--- a/src/cmd/link/testdata/hello.6
+++ b/src/cmd/link/testdata/hello.6
diff --git a/src/cmd/link/testdata/layout.6 b/src/cmd/link/testdata/layout.6
index 8cd5bd2cd..db24ef3e5 100644
--- a/src/cmd/link/testdata/layout.6
+++ b/src/cmd/link/testdata/layout.6
diff --git a/src/cmd/link/testdata/layout.s b/src/cmd/link/testdata/layout.s
index 0d492c5af..c3e55ef49 100644
--- a/src/cmd/link/testdata/layout.s
+++ b/src/cmd/link/testdata/layout.s
@@ -5,7 +5,7 @@
 // Test of section assignment in layout.go.
 // Each symbol should end up in the section named by the symbol name prefix (up to the underscore).
 
-#include "../../ld/textflag.h"
+#include "textflag.h"
 
 TEXT text_start(SB),7,$0
 	MOVQ $rodata_sym(SB), AX
diff --git a/src/cmd/link/testdata/link.hello.darwin.amd64 b/src/cmd/link/testdata/link.hello.darwin.amd64
index b1f0a93b2..0bd475dd8 100644
--- a/src/cmd/link/testdata/link.hello.darwin.amd64
+++ b/src/cmd/link/testdata/link.hello.darwin.amd64
@@ -6,8 +6,8 @@
 *
 00000060  00 00 00 00 00 00 00 00  19 00 00 00 38 01 00 00  |............8...|
 00000070  5f 5f 54 45 58 54 00 00  00 00 00 00 00 00 00 00  |__TEXT..........|
-00000080  00 10 00 00 00 00 00 00  d6 10 00 00 00 00 00 00  |................|
-00000090  00 00 00 00 00 00 00 00  d6 10 00 00 00 00 00 00  |................|
+00000080  00 10 00 00 00 00 00 00  b0 10 00 00 00 00 00 00  |................|
+00000090  00 00 00 00 00 00 00 00  b0 10 00 00 00 00 00 00  |................|
 000000a0  07 00 00 00 05 00 00 00  03 00 00 00 00 00 00 00  |................|
 000000b0  5f 5f 74 65 78 74 00 00  00 00 00 00 00 00 00 00  |__text..........|
 000000c0  5f 5f 54 45 58 54 00 00  00 00 00 00 00 00 00 00  |__TEXT..........|
@@ -21,7 +21,7 @@
 *
 00000150  5f 5f 66 75 6e 63 74 61  62 00 00 00 00 00 00 00  |__functab.......|
 00000160  5f 5f 54 45 58 54 00 00  00 00 00 00 00 00 00 00  |__TEXT..........|
-00000170  20 20 00 00 00 00 00 00  b6 00 00 00 00 00 00 00  |  ..............|
+00000170  20 20 00 00 00 00 00 00  90 00 00 00 00 00 00 00  |  ..............|
 00000180  20 10 00 00 00 00 00 00  00 00 00 00 00 00 00 00  | ...............|
 *
 000001a0  19 00 00 00 98 00 00 00  5f 5f 44 41 54 41 00 00  |........__DATA..|
@@ -48,10 +48,7 @@
 00001070  00 00 00 00 00 00 00 00  5f 72 74 30 5f 67 6f 00  |........_rt0_go.|
 00001080  02 20 00 04 20 00 06 05  02 05 02 05 02 05 02 02  |. .. ...........|
 00001090  02 02 02 05 02 02 02 01  00 00 00 00 00 00 00 00  |................|
-000010a0  02 00 00 00 88 00 00 00  2f 55 73 65 72 73 2f 72  |......../Users/r|
-000010b0  73 63 2f 67 2f 67 6f 2f  73 72 63 2f 63 6d 64 2f  |sc/g/go/src/cmd/|
-000010c0  6c 69 6e 6b 2f 74 65 73  74 64 61 74 61 2f 68 65  |link/testdata/he|
-000010d0  6c 6c 6f 2e 73 00 00 00  00 00 00 00 00 00 00 00  |llo.s...........|
+000010a0  02 00 00 00 88 00 00 00  68 65 6c 6c 6f 2e 73 00  |........hello.s.|
 *
 00002000  68 65 6c 6c 6f 20 77 6f  72 6c 64 0a              |hello world.|
 0000200c
diff --git a/src/cmd/link/testdata/pclntab.6 b/src/cmd/link/testdata/pclntab.6
index 918411ca5..9e7f9afdb 100644
--- a/src/cmd/link/testdata/pclntab.6
+++ b/src/cmd/link/testdata/pclntab.6
diff --git a/src/cmd/link/testdata/pclntab.s b/src/cmd/link/testdata/pclntab.s
index 22c4ee0de..12dac70b0 100644
--- a/src/cmd/link/testdata/pclntab.s
+++ b/src/cmd/link/testdata/pclntab.s
@@ -1746,6 +1746,6 @@ TEXT start(SB),7,$0
 	CALL func0(SB)
 	CALL func1(SB)
 	CALL func2(SB)
-	MOVQ $pclntab(SB), AX
+	MOVQ $runtime·pclntab(SB), AX
 
 	RET
diff --git a/src/cmd/nm/nm.go b/src/cmd/nm/nm.go
index a4036184e..3089e481b 100644
--- a/src/cmd/nm/nm.go
+++ b/src/cmd/nm/nm.go
@@ -6,13 +6,13 @@ package main
 
 import (
 	"bufio"
-	"bytes"
 	"flag"
 	"fmt"
-	"io"
 	"log"
 	"os"
 	"sort"
+
+	"cmd/internal/objfile"
 )
 
 func usage() {
@@ -85,55 +85,22 @@ func errorf(format string, args ...interface{}) {
 	exitCode = 1
 }
 
-type Sym struct {
-	Addr uint64
-	Size int64
-	Code rune
-	Name string
-	Type string
-}
-
-var parsers = []struct {
-	prefix []byte
-	parse  func(*os.File) []Sym
-}{
-	{[]byte("!<arch>\n"), goobjSymbols},
-	{[]byte("go object "), goobjSymbols},
-	{[]byte("\x7FELF"), elfSymbols},
-	{[]byte("\xFE\xED\xFA\xCE"), machoSymbols},
-	{[]byte("\xFE\xED\xFA\xCF"), machoSymbols},
-	{[]byte("\xCE\xFA\xED\xFE"), machoSymbols},
-	{[]byte("\xCF\xFA\xED\xFE"), machoSymbols},
-	{[]byte("MZ"), peSymbols},
-	{[]byte("\x00\x00\x01\xEB"), plan9Symbols}, // 386
-	{[]byte("\x00\x00\x04\x07"), plan9Symbols}, // mips
-	{[]byte("\x00\x00\x06\x47"), plan9Symbols}, // arm
-	{[]byte("\x00\x00\x8A\x97"), plan9Symbols}, // amd64
-}
-
 func nm(file string) {
-	f, err := os.Open(file)
+	f, err := objfile.Open(file)
 	if err != nil {
 		errorf("%v", err)
 		return
 	}
 	defer f.Close()
 
-	buf := make([]byte, 16)
-	io.ReadFull(f, buf)
-	f.Seek(0, 0)
-
-	var syms []Sym
-	for _, p := range parsers {
-		if bytes.HasPrefix(buf, p.prefix) {
-			syms = p.parse(f)
-			goto HaveSyms
-		}
+	syms, err := f.Symbols()
+	if err != nil {
+		errorf("reading %s: %v", file, err)
+	}
+	if len(syms) == 0 {
+		errorf("reading %s: no symbols", file)
 	}
-	errorf("%v: unknown file format", file)
-	return
 
-HaveSyms:
 	switch *sortOrder {
 	case "address":
 		sort.Sort(byAddr(syms))
@@ -165,19 +132,19 @@ HaveSyms:
 	w.Flush()
 }
 
-type byAddr []Sym
+type byAddr []objfile.Sym
 
 func (x byAddr) Len() int           { return len(x) }
 func (x byAddr) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
 func (x byAddr) Less(i, j int) bool { return x[i].Addr < x[j].Addr }
 
-type byName []Sym
+type byName []objfile.Sym
 
 func (x byName) Len() int           { return len(x) }
 func (x byName) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
 func (x byName) Less(i, j int) bool { return x[i].Name < x[j].Name }
 
-type bySize []Sym
+type bySize []objfile.Sym
 
 func (x bySize) Len() int           { return len(x) }
 func (x bySize) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
diff --git a/src/cmd/nm/nm_test.go b/src/cmd/nm/nm_test.go
index 74773877f..f447e8e49 100644
--- a/src/cmd/nm/nm_test.go
+++ b/src/cmd/nm/nm_test.go
@@ -77,7 +77,7 @@ func TestNM(t *testing.T) {
 		"elf/testdata/gcc-amd64-linux-exec",
 		"macho/testdata/gcc-386-darwin-exec",
 		"macho/testdata/gcc-amd64-darwin-exec",
-		"pe/testdata/gcc-amd64-mingw-exec",
+		// "pe/testdata/gcc-amd64-mingw-exec", // no symbols!
 		"pe/testdata/gcc-386-mingw-exec",
 		"plan9obj/testdata/amd64-plan9-exec",
 		"plan9obj/testdata/386-plan9-exec",
@@ -87,7 +87,7 @@ func TestNM(t *testing.T) {
 		cmd := exec.Command(testnmpath, exepath)
 		out, err := cmd.CombinedOutput()
 		if err != nil {
-			t.Fatalf("go tool nm %v: %v\n%s", exepath, err, string(out))
+			t.Errorf("go tool nm %v: %v\n%s", exepath, err, string(out))
 		}
 	}
 
diff --git a/src/cmd/nm/pe.go b/src/cmd/nm/pe.go
deleted file mode 100644
index 52d05e51d..000000000
--- a/src/cmd/nm/pe.go
+++ /dev/null
@@ -1,98 +0,0 @@
-// Copyright 2013 The Go Authors.  All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Parsing of PE executables (Microsoft Windows).
-
-package main
-
-import (
-	"debug/pe"
-	"os"
-	"sort"
-)
-
-func peSymbols(f *os.File) []Sym {
-	p, err := pe.NewFile(f)
-	if err != nil {
-		errorf("parsing %s: %v", f.Name(), err)
-		return nil
-	}
-
-	// Build sorted list of addresses of all symbols.
-	// We infer the size of a symbol by looking at where the next symbol begins.
-	var addrs []uint64
-
-	var imageBase uint64
-	switch oh := p.OptionalHeader.(type) {
-	case *pe.OptionalHeader32:
-		imageBase = uint64(oh.ImageBase)
-	case *pe.OptionalHeader64:
-		imageBase = oh.ImageBase
-	default:
-		errorf("parsing %s: file format not recognized", f.Name())
-		return nil
-	}
-
-	var syms []Sym
-	for _, s := range p.Symbols {
-		const (
-			N_UNDEF = 0  // An undefined (extern) symbol
-			N_ABS   = -1 // An absolute symbol (e_value is a constant, not an address)
-			N_DEBUG = -2 // A debugging symbol
-		)
-		sym := Sym{Name: s.Name, Addr: uint64(s.Value), Code: '?'}
-		switch s.SectionNumber {
-		case N_UNDEF:
-			sym.Code = 'U'
-		case N_ABS:
-			sym.Code = 'C'
-		case N_DEBUG:
-			sym.Code = '?'
-		default:
-			if s.SectionNumber < 0 {
-				errorf("parsing %s: invalid section number %d", f.Name(), s.SectionNumber)
-				return nil
-			}
-			if len(p.Sections) < int(s.SectionNumber) {
-				errorf("parsing %s: section number %d is large then max %d", f.Name(), s.SectionNumber, len(p.Sections))
-				return nil
-			}
-			sect := p.Sections[s.SectionNumber-1]
-			const (
-				text  = 0x20
-				data  = 0x40
-				bss   = 0x80
-				permX = 0x20000000
-				permR = 0x40000000
-				permW = 0x80000000
-			)
-			ch := sect.Characteristics
-			switch {
-			case ch&text != 0:
-				sym.Code = 'T'
-			case ch&data != 0:
-				if ch&permW == 0 {
-					sym.Code = 'R'
-				} else {
-					sym.Code = 'D'
-				}
-			case ch&bss != 0:
-				sym.Code = 'B'
-			}
-			sym.Addr += imageBase + uint64(sect.VirtualAddress)
-		}
-		syms = append(syms, sym)
-		addrs = append(addrs, sym.Addr)
-	}
-
-	sort.Sort(uint64s(addrs))
-	for i := range syms {
-		j := sort.Search(len(addrs), func(x int) bool { return addrs[x] > syms[i].Addr })
-		if j < len(addrs) {
-			syms[i].Size = int64(addrs[j] - syms[i].Addr)
-		}
-	}
-
-	return syms
-}
diff --git a/src/cmd/nm/plan9obj.go b/src/cmd/nm/plan9obj.go
deleted file mode 100644
index 006c66ebf..000000000
--- a/src/cmd/nm/plan9obj.go
+++ /dev/null
@@ -1,48 +0,0 @@
-// Copyright 2014 The Go Authors.  All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Parsing of Plan 9 a.out executables.
-
-package main
-
-import (
-	"debug/plan9obj"
-	"os"
-	"sort"
-)
-
-func plan9Symbols(f *os.File) []Sym {
-	p, err := plan9obj.NewFile(f)
-	if err != nil {
-		errorf("parsing %s: %v", f.Name(), err)
-		return nil
-	}
-
-	plan9Syms, err := p.Symbols()
-	if err != nil {
-		errorf("parsing %s: %v", f.Name(), err)
-		return nil
-	}
-
-	// Build sorted list of addresses of all symbols.
-	// We infer the size of a symbol by looking at where the next symbol begins.
-	var addrs []uint64
-	for _, s := range plan9Syms {
-		addrs = append(addrs, s.Value)
-	}
-	sort.Sort(uint64s(addrs))
-
-	var syms []Sym
-
-	for _, s := range plan9Syms {
-		sym := Sym{Addr: s.Value, Name: s.Name, Code: rune(s.Type)}
-		i := sort.Search(len(addrs), func(x int) bool { return addrs[x] > s.Value })
-		if i < len(addrs) {
-			sym.Size = int64(addrs[i] - s.Value)
-		}
-		syms = append(syms, sym)
-	}
-
-	return syms
-}
diff --git a/src/cmd/objdump/main.go b/src/cmd/objdump/main.go
index 9922dcc02..1e4163296 100644
--- a/src/cmd/objdump/main.go
+++ b/src/cmd/objdump/main.go
@@ -101,7 +101,7 @@ func main() {
 	keep := syms[:0]
 	for _, sym := range syms {
 		switch sym.Name {
-		case "text", "_text", "etext", "_etext":
+		case "runtime.text", "text", "_text", "runtime.etext", "etext", "_etext":
 			// drop
 		default:
 			keep = append(keep, sym)
@@ -118,7 +118,7 @@ func main() {
 		i := sort.Search(len(syms), func(i int) bool { return syms[i].Addr > addr })
 		if i > 0 {
 			s := syms[i-1]
-			if s.Addr <= addr && addr < s.Addr+uint64(s.Size) && s.Name != "etext" && s.Name != "_etext" {
+			if s.Addr <= addr && addr < s.Addr+uint64(s.Size) && s.Name != "runtime.etext" && s.Name != "etext" && s.Name != "_etext" {
 				return s.Name, s.Addr
 			}
 		}
@@ -355,11 +355,20 @@ func loadTables(f *os.File) (textStart uint64, textData, symtab, pclntab []byte,
 			textStart = imageBase + uint64(sect.VirtualAddress)
 			textData, _ = sect.Data()
 		}
-		if pclntab, err = loadPETable(obj, "pclntab", "epclntab"); err != nil {
-			return 0, nil, nil, nil, err
+		if pclntab, err = loadPETable(obj, "runtime.pclntab", "runtime.epclntab"); err != nil {
+			// We didn't find the symbols, so look for the names used in 1.3 and earlier.
+			// TODO: Remove code looking for the old symbols when we no longer care about 1.3.
+			var err2 error
+			if pclntab, err2 = loadPETable(obj, "pclntab", "epclntab"); err2 != nil {
+				return 0, nil, nil, nil, err
+			}
 		}
-		if symtab, err = loadPETable(obj, "symtab", "esymtab"); err != nil {
-			return 0, nil, nil, nil, err
+		if symtab, err = loadPETable(obj, "runtime.symtab", "runtime.esymtab"); err != nil {
+			// Same as above.
+			var err2 error
+			if symtab, err2 = loadPETable(obj, "symtab", "esymtab"); err2 != nil {
+				return 0, nil, nil, nil, err
+			}
 		}
 		return textStart, textData, symtab, pclntab, nil
 	}
@@ -369,11 +378,20 @@ func loadTables(f *os.File) (textStart uint64, textData, symtab, pclntab []byte,
 		if sect := obj.Section("text"); sect != nil {
 			textData, _ = sect.Data()
 		}
-		if pclntab, err = loadPlan9Table(obj, "pclntab", "epclntab"); err != nil {
-			return 0, nil, nil, nil, err
+		if pclntab, err = loadPlan9Table(obj, "runtime.pclntab", "runtime.epclntab"); err != nil {
+			// We didn't find the symbols, so look for the names used in 1.3 and earlier.
+			// TODO: Remove code looking for the old symbols when we no longer care about 1.3.
+			var err2 error
+			if pclntab, err2 = loadPlan9Table(obj, "pclntab", "epclntab"); err2 != nil {
+				return 0, nil, nil, nil, err
+			}
 		}
-		if symtab, err = loadPlan9Table(obj, "symtab", "esymtab"); err != nil {
-			return 0, nil, nil, nil, err
+		if symtab, err = loadPlan9Table(obj, "runtime.symtab", "runtime.esymtab"); err != nil {
+			// Same as above.
+			var err2 error
+			if symtab, err2 = loadPlan9Table(obj, "symtab", "esymtab"); err2 != nil {
+				return 0, nil, nil, nil, err
+			}
 		}
 		return textStart, textData, symtab, pclntab, nil
 	}
diff --git a/src/cmd/yacc/Makefile b/src/cmd/yacc/Makefile
deleted file mode 100644
index f8c8169bd..000000000
--- a/src/cmd/yacc/Makefile
+++ /dev/null
@@ -1,12 +0,0 @@
-# Copyright 2009 The Go Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style
-# license that can be found in the LICENSE file.
-
-TARG=expr$(shell go env GOEXE)
-
-$(TARG): yacc.go expr.y
-	go run yacc.go -p expr expr.y
-	go build -o $(TARG) y.go
-
-clean:
-	rm -f y.go y.output $(TARG)
diff --git a/src/cmd/yacc/doc.go b/src/cmd/yacc/doc.go
index ceaaf2448..702c9f0d2 100644
--- a/src/cmd/yacc/doc.go
+++ b/src/cmd/yacc/doc.go
@@ -20,8 +20,9 @@ written in C and documented at
 Adepts of the original yacc will have no trouble adapting to this
 form of the tool.
 
-The file expr.y in this directory is a yacc grammar for a very simple
-expression parser.  It needs the flag "-p expr" (see below).
+The directory $GOROOT/cmd/yacc/testdata/expr is a yacc program
+for a very simple expression parser. See expr.y and main.go in that
+directory for examples of how to write and build yacc programs.
 
 The generated parser is reentrant. Parse expects to be given an
 argument that conforms to the following interface:
diff --git a/src/cmd/yacc/testdata/expr/README b/src/cmd/yacc/testdata/expr/README
new file mode 100644
index 000000000..302ef57a7
--- /dev/null
+++ b/src/cmd/yacc/testdata/expr/README
@@ -0,0 +1,20 @@
+This directory contains a simple program demonstrating how to use
+the Go version of yacc.
+
+To build it:
+
+	$ go generate
+	$ go build
+
+or
+
+	$ go generate
+	$ go run expr.go
+
+The file main.go contains the "go generate" command to run yacc to
+create expr.go from expr.y. It also has the package doc comment,
+as godoc will not scan the .y file.
+
+The actual implementation is in expr.y.
+
+The program is not installed in the binary distributions of Go.
diff --git a/src/cmd/yacc/expr.y b/src/cmd/yacc/testdata/expr/expr.y
index 77e9259da..09451949f 100644
--- a/src/cmd/yacc/expr.y
+++ b/src/cmd/yacc/testdata/expr/expr.y
@@ -11,11 +11,6 @@
 
 %{
 
-// This tag will be copied to the generated file to prevent that file
-// confusing a future build.
-
-// +build ignore
-
 package main
 
 import (
diff --git a/src/cmd/yacc/testdata/expr/main.go b/src/cmd/yacc/testdata/expr/main.go
new file mode 100644
index 000000000..8d5b6911f
--- /dev/null
+++ b/src/cmd/yacc/testdata/expr/main.go
@@ -0,0 +1,15 @@
+// Copyright 2014 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This file holds the go generate command to run yacc on the grammar in expr.y.
+// To build expr:
+//	% go generate
+//	% go build
+
+//go:generate -command yacc go tool yacc
+//go:generate yacc -o expr.go -p "expr" expr.y
+
+// Expr is a simple expression evaluator that serves as a working example of
+// how to use Go's yacc implemenation.
+package main