/* * obj.c * routines universal to all object files */#include <u.h>#include <libc.h>#include <bio.h>#include <ar.h>#include <mach.h>#include "obj.h" #define islocal(t)	((t)=='a' || (t)=='p') enum{	NNAMES	= 50,	MAXIS	= 8,		/* max length to determine if a file is a .? file */	MAXOFF	= 0x7fffffff,	/* larger than any possible local offset */	NHASH	= 1024,		/* must be power of two */	HASHMUL	= 79L,}; int	_is2(char*),		/* in [$OS].c */	_is5(char*),	_is6(char*),	_is7(char*),	_is8(char*),	_is9(char*),	_isk(char*),	_isq(char*),	_isv(char*),	_isu(char*),	_read2(Biobuf*, Prog*),	_read5(Biobuf*, Prog*),	_read6(Biobuf*, Prog*),	_read7(Biobuf*, Prog*),	_read8(Biobuf*, Prog*),	_read9(Biobuf*, Prog*),	_readk(Biobuf*, Prog*),	_readq(Biobuf*, Prog*),	_readv(Biobuf*, Prog*),	_readu(Biobuf*, Prog*); typedef struct Obj	Obj;typedef struct Symtab	Symtab; struct	Obj		/* functions to handle each intermediate (.$O) file */{	char	*name;				/* name of each $O file */	int	(*is)(char*);			/* test for each type of $O file */	int	(*read)(Biobuf*, Prog*);	/* read for each type of $O file*/}; static Obj	obj[] ={			/* functions to identify and parse each type of obj */	[Obj68020]	"68020 .2",	_is2, _read2,	[ObjAmd64]	"amd64 .6",	_is6, _read6,	[ObjArm]	"arm .5",	_is5, _read5,	[ObjAlpha]	"alpha .7",	_is7, _read7,	[Obj386]	"386 .8",	_is8, _read8,	[ObjSparc]	"sparc .k",	_isk, _readk,	[ObjPower]	"power .q",	_isq, _readq,	[ObjMips]	"mips .v",	_isv, _readv,	[ObjSparc64]	"sparc64 .u",	_isu, _readu,	[ObjPower64]	"power64 .9",	_is9, _read9,	[Maxobjtype]	0, 0}; struct	Symtab{	struct	Sym 	s;	struct	Symtab	*next;}; static	Symtab *hash[NHASH];static	Sym	*names[NNAMES];	/* working set of active names */ static	int	processprog(Prog*,int);	/* decode each symbol reference */static	void	objreset(void);static	void	objlookup(int, char *, int, uint);static	void 	objupdate(int, int); intobjtype(Biobuf *bp, char **name){	int i;	char buf[MAXIS]; 	if(Bread(bp, buf, MAXIS) < MAXIS)		return -1;	Bseek(bp, -MAXIS, 1);	for (i = 0; i < Maxobjtype; i++) {		if (obj[i].is && (*obj[i].is)(buf)) {			if (name)				*name = obj[i].name;			return i;		}	}	return -1;} intisar(Biobuf *bp){	int n;	char magbuf[SARMAG]; 	n = Bread(bp, magbuf, SARMAG);	if(n == SARMAG && strncmp(magbuf, ARMAG, SARMAG) == 0)		return 1;	return 0;} /* * determine what kind of object file this is and process it. * return whether or not this was a recognized intermediate file. */intreadobj(Biobuf *bp, int objtype){	Prog p; 	if (objtype < 0 || objtype >= Maxobjtype || obj[objtype].is == 0)		return 1;	objreset();	while ((*obj[objtype].read)(bp, &p))		if (!processprog(&p, 1))			return 0;	return 1;} intreadar(Biobuf *bp, int objtype, vlong end, int doautos){	Prog p; 	if (objtype < 0 || objtype >= Maxobjtype || obj[objtype].is == 0)		return 1;	objreset();	while ((*obj[objtype].read)(bp, &p) && Boffset(bp) < end)		if (!processprog(&p, doautos))			return 0;	return 1;} /* *	decode a symbol reference or definition */static	intprocessprog(Prog *p, int doautos){	if(p->kind == aNone)		return 1;	if(p->sym < 0 || p->sym >= NNAMES)		return 0;	switch(p->kind)	{	case aName:		if (!doautos)		if(p->type != 'U' && p->type != 'b')			break;		objlookup(p->sym, p->id, p->type, p->sig);		break;	case aText:		objupdate(p->sym, 'T');		break;	case aData:		objupdate(p->sym, 'D');		break;	default:		break;	}	return 1;} /* * find the entry for s in the symbol array. * make a new entry if it is not already there. */static voidobjlookup(int id, char *name, int type, uint sig){	long h;	char *cp;	Sym *s;	Symtab *sp; 	s = names[id];	if(s && strcmp(s->name, name) == 0) {		s->type = type;		s->sig = sig;		return;	} 	h = *name;	for(cp = name+1; *cp; h += *cp++)		h *= HASHMUL;	if(h < 0)		h = ~h;	h &= (NHASH-1);	if (type == 'U' || type == 'b' || islocal(type)) {		for(sp = hash[h]; sp; sp = sp->next)			if(strcmp(sp->s.name, name) == 0) {				switch(sp->s.type) {				case 'T':				case 'D':				case 'U':					if (type == 'U') {						names[id] = &sp->s;						return;					}					break;				case 't':				case 'd':				case 'b':					if (type == 'b') {						names[id] = &sp->s;						return;					}					break;				case 'a':				case 'p':					if (islocal(type)) {						names[id] = &sp->s;						return;					}					break;				default:					break;				}			}	}	sp = malloc(sizeof(Symtab));	sp->s.name = name;	sp->s.type = type;	sp->s.sig = sig;	sp->s.value = islocal(type) ? MAXOFF : 0;	names[id] = &sp->s;	sp->next = hash[h];	hash[h] = sp;	return;}/* *	traverse the symbol lists */voidobjtraverse(void (*fn)(Sym*, void*), void *pointer){	int i;	Symtab *s; 	for(i = 0; i < NHASH; i++)		for(s = hash[i]; s; s = s->next)			(*fn)(&s->s, pointer);} /* * update the offset information for a 'a' or 'p' symbol in an intermediate file */void_offset(int id, vlong off){	Sym *s; 	s = names[id];	if (s && s->name[0] && islocal(s->type) && s->value > off)		s->value = off;} /* * update the type of a global text or data symbol */static void objupdate(int id, int type){	Sym *s; 	s = names[id];	if (s && s->name[0])		if (s->type == 'U')			s->type = type;		else if (s->type == 'b')			s->type = tolower(type);} /* * look for the next file in an archive */intnextar(Biobuf *bp, int offset, char *buf){	struct ar_hdr a;	int i, r;	long arsize; 	if (offset&01)		offset++;	Bseek(bp, offset, 0);	r = Bread(bp, &a, SAR_HDR);	if(r != SAR_HDR)		return 0;	if(strncmp(a.fmag, ARFMAG, sizeof(a.fmag)))		return -1;	for(i=0; i<sizeof(a.name) && i<SARNAME && a.name[i] != ' '; i++)		buf[i] = a.name[i];	buf[i] = 0;	arsize = strtol(a.size, 0, 0);	if (arsize&1)		arsize++;	return arsize + SAR_HDR;} static voidobjreset(void){	int i;	Symtab *s, *n; 	for(i = 0; i < NHASH; i++) {		for(s = hash[i]; s; s = n) {			n = s->next;			free(s->s.name);			free(s);		}		hash[i] = 0;	}	memset(names, 0, sizeof names);}