cmd/ld: replace -hostobj with -linkmode

Still disabled. Need to fix TLS.

R=golang-dev, minux.ma, bradfitz
CC=golang-dev
https://codereview.appspot.com/7783044

11 files changed, 75 insertions, 58 deletions

diff --git a/src/cmd/5l/asm.c b/src/cmd/5l/asm.c
index f81ec2ff9..a1220a38e 100644
--- a/src/cmd/5l/asm.c
+++ b/src/cmd/5l/asm.c
@@ -605,7 +605,7 @@ asmb(void)
 					Bprint(&bso, "%5.2f dwarf\n", cputime());
 				dwarfemitdebugsections();
 				
-				if(isobj)
+				if(linkmode == LinkExternal)
 					elfemitreloc();
 			}
 			break;
diff --git a/src/cmd/5l/obj.c b/src/cmd/5l/obj.c
index f70cb6c33..a025db209 100644
--- a/src/cmd/5l/obj.c
+++ b/src/cmd/5l/obj.c
@@ -117,6 +117,7 @@ main(int argc, char *argv[])
 	flagcount("f", "ignore version mismatch", &debug['f']);
 	flagcount("g", "disable go package data checks", &debug['g']);
 	flagstr("k", "sym: set field tracking symbol", &tracksym);
+	flagfn1("linkmode", "mode: set link mode (internal, external, auto)", setlinkmode);
 	flagcount("n", "dump symbol table", &debug['n']);
 	flagstr("o", "outfile: set output file", &outfile);
 	flagcount("p", "insert profiling code", &debug['p']);
@@ -135,6 +136,11 @@ main(int argc, char *argv[])
 	if(argc != 1)
 		usage();
 
+	if(linkmode != Linkinternal) {
+		diag("only -linkmode=internal is supported");
+		errorexit();
+	}
+
 	libinit();
 
 	if(HEADTYPE == -1)
diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c
index de6ea3a63..07ba59ad9 100644
--- a/src/cmd/6l/asm.c
+++ b/src/cmd/6l/asm.c
@@ -711,7 +711,7 @@ asmb(void)
 
 				dwarfemitdebugsections();
 				
-				if(isobj)
+				if(linkmode == LinkExternal)
 					elfemitreloc();
 			}
 			break;
@@ -735,7 +735,7 @@ asmb(void)
 			dwarfemitdebugsections();
 			break;
 		case Hdarwin:
-			if(isobj)
+			if(linkmode == LinkExternal)
 				machoemitreloc();
 			break;
 		}
diff --git a/src/cmd/6l/obj.c b/src/cmd/6l/obj.c
index 91569794b..3775df9de 100644
--- a/src/cmd/6l/obj.c
+++ b/src/cmd/6l/obj.c
@@ -109,7 +109,7 @@ main(int argc, char *argv[])
 	flagcount("d", "disable dynamic executable", &debug['d']);
 	flagcount("f", "ignore version mismatch", &debug['f']);
 	flagcount("g", "disable go package data checks", &debug['g']);
-	flagcount("hostobj", "generate host object file", &isobj);
+	flagfn1("linkmode", "mode: set link mode (internal, external, auto)", setlinkmode);
 	flagstr("k", "sym: set field tracking symbol", &tracksym);
 	flagcount("n", "dump symbol table", &debug['n']);
 	flagstr("o", "outfile: set output file", &outfile);
@@ -124,10 +124,6 @@ main(int argc, char *argv[])
 	flagcount("w", "disable DWARF generation", &debug['w']);
 	
 	flagparse(&argc, &argv, usage);
-	
-	// TODO: link mode flag instead of isobj
-	if(isobj)
-		linkmode = LinkExternal;
 
 	if(argc != 1)
 		usage();
@@ -137,17 +133,19 @@ main(int argc, char *argv[])
 	if(HEADTYPE == -1)
 		HEADTYPE = headtype(goos);
 
-	if(isobj) {
-		switch(HEADTYPE) {
-		default:
-			sysfatal("cannot use -hostobj with -H %s", headstr(HEADTYPE));
-		case Hdarwin:
-		case Hfreebsd:
-		case Hlinux:
-		case Hnetbsd:
-		case Hopenbsd:
-			break;
-		}
+	switch(HEADTYPE) {
+	default:
+		if(linkmode == LinkAuto)
+			linkmode = LinkInternal;
+		if(linkmode == LinkExternal)
+			sysfatal("cannot use -linkmode=external with -H %s", headstr(HEADTYPE));
+		break;
+	case Hdarwin:
+	case Hfreebsd:
+	case Hlinux:
+	case Hnetbsd:
+	case Hopenbsd:
+		break;
 	}
 
 	if(outfile == nil) {
diff --git a/src/cmd/8l/asm.c b/src/cmd/8l/asm.c
index 402360d70..bfeb13839 100644
--- a/src/cmd/8l/asm.c
+++ b/src/cmd/8l/asm.c
@@ -671,7 +671,7 @@ asmb(void)
 					Bprint(&bso, "%5.2f dwarf\n", cputime());
 				dwarfemitdebugsections();
 				
-				if(isobj)
+				if(linkmode == LinkExternal)
 					elfemitreloc();
 			}
 			break;
@@ -694,7 +694,7 @@ asmb(void)
 			dwarfemitdebugsections();
 			break;
 		case Hdarwin:
-			if(isobj)
+			if(linkmode == LinkExternal)
 				machoemitreloc();
 			break;
 		}
diff --git a/src/cmd/8l/obj.c b/src/cmd/8l/obj.c
index 14c6b6aa9..306e288a3 100644
--- a/src/cmd/8l/obj.c
+++ b/src/cmd/8l/obj.c
@@ -115,7 +115,7 @@ main(int argc, char *argv[])
 	flagcount("d", "disable dynamic executable", &debug['d']);
 	flagcount("f", "ignore version mismatch", &debug['f']);
 	flagcount("g", "disable go package data checks", &debug['g']);
-	flagcount("hostobj", "generate host object file", &isobj);
+	flagfn1("linkmode", "mode: set link mode (internal, external, auto)", setlinkmode);
 	flagstr("k", "sym: set field tracking symbol", &tracksym);
 	flagstr("o", "outfile: set output file", &outfile);
 	flagcount("p", "insert profiling code", &debug['p']);
@@ -131,10 +131,6 @@ main(int argc, char *argv[])
 	
 	flagparse(&argc, &argv, usage);
 
-	// TODO: link mode flag instead of isobj
-	if(isobj)
-		linkmode = LinkExternal;
-
 	if(argc != 1)
 		usage();
 
@@ -143,17 +139,19 @@ main(int argc, char *argv[])
 	if(HEADTYPE == -1)
 		HEADTYPE = headtype(goos);
 
-	if(isobj) {
-		switch(HEADTYPE) {
-		default:
-			sysfatal("cannot use -hostobj with -H %s", headstr(HEADTYPE));
-		case Hdarwin:
-		case Hfreebsd:
-		case Hlinux:
-		case Hnetbsd:
-		case Hopenbsd:
-			break;
-		}
+	switch(HEADTYPE) {
+	default:
+		if(linkmode == LinkAuto)
+			linkmode = LinkInternal;
+		if(linkmode == LinkExternal)
+			sysfatal("cannot use -linkmode=external with -H %s", headstr(HEADTYPE));
+		break;
+	case Hdarwin:
+	case Hfreebsd:
+	case Hlinux:
+	case Hnetbsd:
+	case Hopenbsd:
+		break;
 	}
 
 	if(outfile == nil) {
diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c
index fdf4d043d..b70d4636c 100644
--- a/src/cmd/ld/data.c
+++ b/src/cmd/ld/data.c
@@ -178,11 +178,11 @@ relocsym(Sym *s)
 		switch(r->type) {
 		default:
 			o = 0;
-			if(isobj || archreloc(r, s, &o) < 0)
+			if(linkmode == LinkExternal || archreloc(r, s, &o) < 0)
 				diag("unknown reloc %d", r->type);
 			break;
 		case D_ADDR:
-			if(isobj && r->sym->type != SCONST) {
+			if(linkmode == LinkExternal && r->sym->type != SCONST) {
 				r->done = 0;
 
 				// set up addend for eventual relocation via outer symbol.
@@ -212,7 +212,7 @@ relocsym(Sym *s)
 			break;
 		case D_PCREL:
 			// r->sym can be null when CALL $(constant) is transformed from absolute PC to relative PC call.
-			if(isobj && r->sym && r->sym->type != SCONST && r->sym->sect != cursym->sect) {
+			if(linkmode == LinkExternal && r->sym && r->sym->type != SCONST && r->sym->sect != cursym->sect) {
 				r->done = 0;
 
 				// set up addend for eventual relocation via outer symbol.
@@ -630,7 +630,7 @@ datblk(int32 addr, int32 size)
 			Bprint(&bso, " %.2ux", 0);
 		Bprint(&bso, "\n");
 		
-		if(isobj) {
+		if(linkmode == LinkExternal) {
 			for(i=0; i<sym->nr; i++) {
 				r = &sym->r[i];
 				rsname = "";
diff --git a/src/cmd/ld/elf.c b/src/cmd/ld/elf.c
index 50711a0ec..f5cce9c52 100644
--- a/src/cmd/ld/elf.c
+++ b/src/cmd/ld/elf.c
@@ -758,7 +758,7 @@ elfshbits(Section *sect)
 		sh->flags |= SHF_EXECINSTR;
 	if(sect->rwx & 2)
 		sh->flags |= SHF_WRITE;
-	if(!isobj)
+	if(linkmode != LinkExternal)
 		sh->addr = sect->vaddr;
 	sh->addralign = sect->align;
 	sh->size = sect->len;
@@ -899,7 +899,7 @@ doelf(void)
 	addstring(shstrtab, ".gosymtab");
 	addstring(shstrtab, ".gopclntab");
 	
-	if(isobj) {
+	if(linkmode == LinkExternal) {
 		debug['s'] = 0;
 		debug['d'] = 1;
 
@@ -1131,7 +1131,7 @@ asmbelf(vlong symo)
 	resoff = ELFRESERVE;
 	
 	pph = nil;
-	if(isobj) {
+	if(linkmode == LinkExternal) {
 		/* skip program headers */
 		eh->phoff = 0;
 		eh->phentsize = 0;
@@ -1392,7 +1392,7 @@ elfobj:
 	for(sect=segdata.sect; sect!=nil; sect=sect->next)
 		elfshbits(sect);
 
-	if(isobj) {
+	if(linkmode == LinkExternal) {
 		for(sect=segtext.sect; sect!=nil; sect=sect->next)
 			elfshreloc(sect);
 		for(sect=segdata.sect; sect!=nil; sect=sect->next)
@@ -1415,8 +1415,8 @@ elfobj:
 		sh->size = elfstrsize;
 		sh->addralign = 1;
 
-		// TODO(rsc): Enable for isobj too, once we know it works.
-		if(!isobj)
+		// TODO(rsc): Enable for linkmode == LinkExternal too, once we know it works.
+		if(linkmode != LinkExternal)
 			dwarfaddelfheaders();
 	}
 
@@ -1440,12 +1440,12 @@ elfobj:
 
 	if(flag_shared)
 		eh->type = ET_DYN;
-	else if(isobj)
+	else if(linkmode == LinkExternal)
 		eh->type = ET_REL;
 	else
 		eh->type = ET_EXEC;
 
-	if(!isobj)
+	if(linkmode != LinkExternal)
 		eh->entry = entryvalue();
 
 	eh->version = EV_CURRENT;
@@ -1462,7 +1462,7 @@ elfobj:
 	a += elfwriteshdrs();
 	if(!debug['d'])
 		a += elfwriteinterp();
-	if(!isobj) {
+	if(linkmode != LinkExternal) {
 		if(HEADTYPE == Hnetbsd)
 			a += elfwritenetbsdsig();
 		if(HEADTYPE == Hopenbsd)
diff --git a/src/cmd/ld/go.c b/src/cmd/ld/go.c
index ff1f5f437..f933cbba3 100644
--- a/src/cmd/ld/go.c
+++ b/src/cmd/ld/go.c
@@ -476,12 +476,10 @@ loadcgo(char *file, char *pkg, char *p, int n)
 		if(strcmp(f[0], "cgo_import_static") == 0) {
 			if(nf != 2)
 				goto err;
-			if(isobj) {
-				local = f[1];
-				s = lookup(local, 0);
-				s->type = SHOSTOBJ;
-				s->size = 0;
-			}
+			local = f[1];
+			s = lookup(local, 0);
+			s->type = SHOSTOBJ;
+			s->size = 0;
 			continue;
 		}
 
@@ -925,3 +923,18 @@ importcycles(void)
 	for(p=pkgall; p; p=p->all)
 		cycle(p);
 }
+
+void
+setlinkmode(char *arg)
+{
+	if(strcmp(arg, "internal") == 0)
+		linkmode = LinkInternal;
+	else if(strcmp(arg, "external") == 0)
+		linkmode = LinkExternal;
+	else if(strcmp(arg, "auto") == 0)
+		linkmode = LinkAuto;
+	else {
+		fprint(2, "unknown link mode -linkmode %s\n", arg);
+		errorexit();
+	}
+}
diff --git a/src/cmd/ld/lib.h b/src/cmd/ld/lib.h
index e5dcdc353..78232c075 100644
--- a/src/cmd/ld/lib.h
+++ b/src/cmd/ld/lib.h
@@ -170,6 +170,7 @@ EXTERN	Segment	segtext;
 EXTERN	Segment	segdata;
 EXTERN	Segment	segdwarf;
 
+void	setlinkmode(char*);
 void	addlib(char *src, char *obj);
 void	addlibpath(char *srcref, char *objref, char *file, char *pkg);
 Section*	addsection(Segment*, char*, int);
diff --git a/src/run.bash b/src/run.bash
index 6c96d5ddd..538d4f6fe 100755
--- a/src/run.bash
+++ b/src/run.bash
@@ -75,10 +75,11 @@ go run $GOROOT/test/run.go - .
 
 [ "$CGO_ENABLED" != 1 ] ||
 (xcd ../misc/cgo/test
-go test
+go test -ldflags '-linkmode=auto'
+go test -ldflags '-linkmode=internal'
 case "$GOHOSTOS-$GOARCH" in
 darwin-386 | darwin-amd64 | freebsd-386 | freebsd-amd64 | linux-386 | linux-amd64 | netbsd-386 | netbsd-amd64 | openbsd-386 | openbsd-amd64)
-	go test -ldflags '-w -hostobj'
+	go test -ldflags '-linkmode=external'
 esac
 ) || exit $?