liblink: create new library based on linker code

There is an enormous amount of code moving around in this CL,
but the code is the same, and it is invoked in the same ways.
This CL is preparation for the new linker structure, not the new
structure itself.

The new library's definition is in include/link.h.

The main change is the use of a Link structure to hold all the
linker-relevant state, replacing the smattering of global variables.
The Link structure should both make it clearer which state must
be carried around and make it possible to parallelize more easily
later.

The main body of the linker has moved into the architecture-independent
cmd/ld directory. That includes the list of known header types, so the
distinction between Hplan9x32 and Hplan9x64 is removed (no other
header type distinguished 32- and 64-bit formats), and code for unused
formats such as ipaq kernels has been deleted.

The code being deleted from 5l, 6l, and 8l reappears in liblink or in ld.
Because multiple files are being merged in the liblink directory,
it is not possible to show the diffs nicely in hg.

The Prog and Addr structures have been unified into an
architecture-independent form and moved to link.h, where they will
be shared by all tools: the assemblers, the compilers, and the linkers.
The unification makes it possible to write architecture-independent
traversal of Prog lists, among other benefits.

The Sym structures cannot be unified: they are too fundamentally
different between the linker and the compilers. Instead, liblink defines
an LSym - a linker Sym - to be used in the Prog and Addr structures,
and the linker now refers exclusively to LSyms. The compilers will
keep using their own syms but will fill out the corresponding LSyms in
the Prog and Addr structures.

Although code from 5l, 6l, and 8l is now in a single library, the
code has been arranged so that only one architecture needs to
be linked into a particular program: 5l will not contain the code
needed for x86 instruction layout, for example.

The object file writing code in liblink/obj.c is from cmd/gc/obj.c.

Preparation for golang.org/s/go13linker work.

This CL does not build by itself. It depends on 35740044
and will be submitted at the same time.

R=iant
CC=golang-dev
https://codereview.appspot.com/35790044

1 files changed, 26 insertions, 305 deletions

diff --git a/src/cmd/8l/l.h b/src/cmd/8l/l.h
index 814aa1458..928e2e49a 100644
--- a/src/cmd/8l/l.h
+++ b/src/cmd/8l/l.h
@@ -31,6 +31,7 @@
 #include	<u.h>
 #include	<libc.h>
 #include	<bio.h>
+#include	<link.h>
 #include	"8.out.h"
 
 #ifndef	EXTERN
@@ -47,136 +48,8 @@ enum
 };
 
 #define	P		((Prog*)0)
-#define	S		((Sym*)0)
-#define	TNAME		(cursym?cursym->name:noname)
-
-typedef	struct	Adr	Adr;
-typedef	struct	Prog	Prog;
-typedef	struct	Sym	Sym;
-typedef	struct	Auto	Auto;
-typedef	struct	Optab	Optab;
-typedef	struct	Reloc	Reloc;
-
-struct	Adr
-{
-	union
-	{
-		int32	u0offset;
-		char	u0scon[8];
-		Prog	*u0cond;	/* not used, but should be D_BRANCH */
-		Ieee	u0ieee;
-		char	*u0sbig;
-	} u0;
-	Sym*	sym;
-	short	type;
-	uchar	index;
-	char	scale;
-	int32	offset2;
-};
-
-#define	offset	u0.u0offset
-#define	scon	u0.u0scon
-#define	cond	u0.u0cond
-#define	ieee	u0.u0ieee
-#define	sbig	u0.u0sbig
-
-struct	Reloc
-{
-	int32	off;
-	uchar	siz;
-	uchar	done;
-	int32	type;
-	int32	add;
-	int32	xadd;
-	Sym*	sym;
-	Sym*	xsym;
-};
-
-struct	Prog
-{
-	Adr	from;
-	Adr	to;
-	Prog*	forwd;
-	Prog*	comefrom;
-	Prog*	link;
-	Prog*	pcond;	/* work on this */
-	int32	pc;
-	int32	spadj;
-	int32	line;
-	short	as;
-	char	width;		/* fake for DATA */
-	char	ft;		/* oclass cache */
-	char	tt;
-	uchar	mark;	/* work on these */
-	uchar	back;
-	uchar	bigjmp;
-};
-#define	datasize	from.scale
-#define	textflag	from.scale
-#define	iscall(p)	((p)->as == ACALL)
-
-struct	Auto
-{
-	Sym*	asym;
-	Auto*	link;
-	int32	aoffset;
-	short	type;
-	Sym*	gotype;
-};
-struct	Sym
-{
-	char*	name;
-	char*	extname;	// name used in external object files
-	short	type;
-	short	version;
-	uchar	dupok;
-	uchar	reachable;
-	uchar	cgoexport;
-	uchar	special;
-	uchar	stkcheck;
-	uchar	hide;
-	int32	value;
-	int32	size;
-	int32	sig;
-	int32	dynid;
-	int32	plt;
-	int32	got;
-	int32	align;	// if non-zero, required alignment in bytes
-	int32	elfsym;
-	int32	args;	// size of stack frame incoming arguments area
-	Sym*	hash;	// in hash table
-	Sym*	allsym;	// in all symbol list
-	Sym*	next;	// in text or data list
-	Sym*	sub;	// in sub list
-	Sym*	outer;	// container of sub
-	Sym*	gotype;
-	Sym*	reachparent;
-	Sym*	queue;
-	char*	file;
-	char*	dynimplib;
-	char*	dynimpvers;
-	struct Section*	sect;
-	struct Hist*	hist;	// for ATEXT
-	
-	// STEXT
-	Auto*	autom;
-	Prog*	text;
-	
-	// SDATA, SBSS
-	uchar*	p;
-	int32	np;
-	int32	maxp;
-	Reloc*	r;
-	int32	nr;
-	int32	maxr;
-};
-struct	Optab
-{
-	short	as;
-	uchar*	ytab;
-	uchar	prefix;
-	uchar	op[13];
-};
+#define	S		((LSym*)0)
+#define	TNAME		(ctxt->cursym?ctxt->cursym->name:noname)
 
 enum
 {
@@ -185,202 +58,50 @@ enum
 	MINLC		= 1,
 	MAXIO		= 8192,
 	MAXHIST		= 40,				/* limit of path elements for history symbols */
-
-	Yxxx		= 0,
-	Ynone,
-	Yi0,
-	Yi1,
-	Yi8,
-	Yi32,
-	Yiauto,
-	Yal,
-	Ycl,
-	Yax,
-	Ycx,
-	Yrb,
-	Yrl,
-	Yrf,
-	Yf0,
-	Yrx,
-	Ymb,
-	Yml,
-	Ym,
-	Ybr,
-	Ycol,
-
-	Ycs,	Yss,	Yds,	Yes,	Yfs,	Ygs,
-	Ygdtr,	Yidtr,	Yldtr,	Ymsw,	Ytask,
-	Ycr0,	Ycr1,	Ycr2,	Ycr3,	Ycr4,	Ycr5,	Ycr6,	Ycr7,
-	Ydr0,	Ydr1,	Ydr2,	Ydr3,	Ydr4,	Ydr5,	Ydr6,	Ydr7,
-	Ytr0,	Ytr1,	Ytr2,	Ytr3,	Ytr4,	Ytr5,	Ytr6,	Ytr7,
-	Ymr, Ymm,
-	Yxr, Yxm,
-	Ymax,
-
-	Zxxx		= 0,
-
-	Zlit,
-	Zlitm_r,
-	Z_rp,
-	Zbr,
-	Zcall,
-	Zcallcon,
-	Zcallind,
-	Zib_,
-	Zib_rp,
-	Zibo_m,
-	Zil_,
-	Zil_rp,
-	Zilo_m,
-	Zjmp,
-	Zjmpcon,
-	Zloop,
-	Zm_o,
-	Zm_r,
-	Zm2_r,
-	Zm_r_xm,
-	Zm_r_i_xm,
-	Zaut_r,
-	Zo_m,
-	Zpseudo,
-	Zr_m,
-	Zr_m_xm,
-	Zr_m_i_xm,
-	Zrp_,
-	Z_ib,
-	Z_il,
-	Zm_ibo,
-	Zm_ilo,
-	Zib_rr,
-	Zil_rr,
-	Zclr,
-	Zibm_r,	/* mmx1,mmx2/mem64,imm8 */
-	Zbyte,
-	Zmov,
-	Zmax,
-
-	Px		= 0,
-	Pe		= 0x66,	/* operand escape */
-	Pm		= 0x0f,	/* 2byte opcode escape */
-	Pq		= 0xff,	/* both escape */
-	Pb		= 0xfe,	/* byte operands */
-	Pf2		= 0xf2,	/* xmm escape 1 */
-	Pf3		= 0xf3,	/* xmm escape 2 */
 };
 
 #pragma	varargck	type	"A"	int
-#pragma	varargck	type	"D"	Adr*
+#pragma	varargck	type	"D"	Addr*
 #pragma	varargck	type	"I"	uchar*
 #pragma	varargck	type	"P"	Prog*
 #pragma	varargck	type	"R"	int
 #pragma	varargck	type	"S"	char*
-#pragma	varargck	type	"Y"	Sym*
+#pragma	varargck	type	"Y"	LSym*
 #pragma	varargck	type	"Z"	char*
 #pragma	varargck	type	"i"	char*
 
-EXTERN	int32	HEADR;
-EXTERN	int32	HEADTYPE;
-EXTERN	int32	INITRND;
-EXTERN	int32	INITTEXT;
-EXTERN	int32	INITDAT;
-EXTERN	char*	INITENTRY;		/* entry point */
-EXTERN	char*	pcstr;
-EXTERN	Auto*	curauto;
-EXTERN	Auto*	curhist;
-EXTERN	Prog*	curp;
-EXTERN	Sym*	cursym;
-EXTERN	Sym*	datap;
+EXTERN	LSym*	datap;
 EXTERN	int	debug[128];
 EXTERN	char	literal[32];
-EXTERN	Sym*	etextp;
 EXTERN	Prog*	firstp;
-EXTERN	uchar	ycover[Ymax*Ymax];
-EXTERN	uchar*	andptr;
-EXTERN	uchar	and[100];
-EXTERN	char	reg[D_NONE];
 EXTERN	int32	lcsize;
-EXTERN	int	maxop;
-EXTERN	int	nerrors;
-EXTERN	char*	noname;
-EXTERN	int32	pc;
 EXTERN	char*	rpath;
 EXTERN	int32	spsize;
-EXTERN	Sym*	symlist;
+EXTERN	LSym*	symlist;
 EXTERN	int32	symsize;
-EXTERN	Sym*	textp;
 EXTERN	int32	textsize;
-EXTERN	Prog	zprg;
-EXTERN	int	dtype;
-EXTERN	int	tlsoffset;
-EXTERN	Sym*	adrgotype;	// type symbol on last Adr read
-EXTERN	Sym*	fromgotype;	// type symbol on last p->from read
 
-extern	Optab	optab[];
-extern	char*	anames[];
-
-int	Aconv(Fmt*);
-int	Dconv(Fmt*);
-int	Iconv(Fmt*);
-int	Pconv(Fmt*);
-int	Rconv(Fmt*);
-int	Sconv(Fmt*);
-void	addhist(int32, int);
-Prog*	appendp(Prog*);
+int	Aconv(Fmt *fp);
+int	Dconv(Fmt *fp);
+int	Iconv(Fmt *fp);
+int	Pconv(Fmt *fp);
+int	Rconv(Fmt *fp);
+int	Sconv(Fmt *fp);
+void	adddynlib(char *lib);
+void	adddynrel(LSym *s, Reloc *r);
+void	adddynrela(LSym *rela, LSym *s, Reloc *r);
+void	adddynsym(Link *ctxt, LSym *s);
+int	archreloc(Reloc *r, LSym *s, vlong *val);
 void	asmb(void);
-void	asmdyn(void);
-void	asmins(Prog*);
-void	asmsym(void);
-int32	atolwhex(char*);
-Prog*	brchain(Prog*);
-Prog*	brloop(Prog*);
-void	cflush(void);
-Prog*	copyp(Prog*);
-vlong	cpos(void);
-double	cputime(void);
-void	diag(char*, ...);
-void	dodata(void);
-void	doelf(void);
-void	doprof1(void);
-void	doprof2(void);
-void	dostkoff(void);
-int32	entryvalue(void);
-void	follow(void);
-void	instinit(void);
+void	diag(char *fmt, ...);
+int	elfreloc1(Reloc *r, vlong sectoff);
+void	elfsetupplt(void);
 void	listinit(void);
-Sym*	lookup(char*, int);
-void	lputb(int32);
-void	lputl(int32);
-void	vputl(uint64);
-void	strnput(char*, int);
-void	main(int, char*[]);
-void*	mal(uint32);
-int	opsize(Prog*);
-void	patch(void);
-Prog*	prg(void);
-int	relinv(int);
-int32	rnd(int32, int32);
-void	s8put(char*);
-void	span(void);
-void	undef(void);
-int32	symaddr(Sym*);
-void	wput(ushort);
-void	wputl(ushort);
-void	xdefine(char*, int, int32);
-
-uint32	machheadr(void);
-vlong		addaddr(Sym *s, Sym *t);
-vlong		addsize(Sym *s, Sym *t);
-vlong		addstring(Sym *s, char *str);
-vlong		adduint16(Sym *s, uint16 v);
-vlong		adduint32(Sym *s, uint32 v);
-vlong		adduint64(Sym *s, uint64 v);
-vlong		adduint8(Sym *s, uint8 v);
-vlong		adduintxx(Sym *s, uint64 v, int wid);
-
-/*
- *	go.c
- */
-void	deadcode(void);
+int	machoreloc1(Reloc *r, vlong sectoff);
+void	main(int argc, char *argv[]);
+int32	rnd(int32 v, int32 r);
+void	s8put(char *n);
+char*	xsymname(LSym *s);
 
 /* Native is little-endian */
 #define	LPUT(a)	lputl(a)