/* * 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{	CHUNK	= 256,		/* number of Syms to allocate at once */	NNAMES	= 50,	MAXIS	= 8,		/* max length to determine if a file is a .? file */	MAXOFF	= 0x7fffffff,	/* larger than any possible local offset */}; int	_is2(char*),		/* in [$OS].c */	_is6(char*),	_is8(char*),	_isk(char*),	_isv(char*),	_isz(char*),	_read2(Biobuf*, Prog*),	_read6(Biobuf*, Prog*),	_read8(Biobuf*, Prog*),	_readk(Biobuf*, Prog*),	_readv(Biobuf*, Prog*),	_readz(Biobuf*, Prog*); typedef struct Obj	Obj; struct	Obj		/* functions to handle each intermediate (.$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]	_is2, _read2,	[ObjSparc]	_isk, _readk,	[ObjMips]	_isv, _readv,	[ObjHobbit]	_isz, _readz,	[Obj386]	_is8, _read8,	[Obj960]	_is6, _read6,	[Maxobjtype]	0, 0}; static	struct	Sym *sym;	/* base of symbol array */static	int	names[NNAMES];	/* working set of active names */static	int	local;		/* start of current local symbols in sym */static	int	global;		/* start of current global symbols in sym */static	long	nsym;		/* number of symbols */static	int	have;		/* current size of symbol cache */ static	int	processprog(Prog*);	/* decode each symbol reference */static	void	objlookup(int, char *, int );static	int 	objupdate(int, int);static	void	assure(int); intobjtype(Biobuf *bp){	int i;	char buf[MAXIS]; 	if(Bread(bp, buf, MAXIS) < MAXIS)		return -1;	Bseek(bp, -MAXIS, 1);	for (i = 0; obj[i].is; i++) {		if ((*obj[i].is)(buf))			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)		return 1;	local = nsym;	global = nsym;	while ((*obj[objtype].read)(bp, &p))		if (!processprog(&p))			return 0;	return 1;} intreadar(Biobuf *bp, int objtype, int end){	Prog p; 	if (objtype < 0 || objtype >= Maxobjtype)		return 1;	local = nsym;	global = nsym;	while ((*obj[objtype].read)(bp, &p) && BOFFSET(bp) < end)		if (!processprog(&p))			return 0;	return 1;} /* *	decode a symbol reference or definition */static	intprocessprog(Prog *p){	if(p->kind == aNone)		return 1;	if(p->sym < 0 || p->sym >= NNAMES)		return 0;	switch(p->kind)	{	case aName:		objlookup(p->sym, p->id, p->type);		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){	int i;	Sym *s; 	if (sym) {		s = &sym[names[id]];		i = islocal(type) ? local : global;		if (names[id] >= i && strncmp(s->name, name, NNAME) == 0) {			s->type = type;			return;		}		for (s = &sym[i]; i < nsym; i++, s++) {			if (strncmp(s->name, name, NNAME) == 0) {				switch(s->type) {				case 'T':				case 'D':				case 'U':					if (type == 'U') {						names[id] = i;						return;					}					break;				case 't':				case 'd':				case 'b':					if (type == 'b') {						names[id] = i;						return;					}					break;				case 'a':				case 'p':					if (type == 'a' || type == 'p') {						names[id] = i;						return;					}					break;				default:					break;				}			}		}	}	names[id] = nsym++;	assure(nsym);	s = &sym[names[id]]; 	memmove(s->name, name, NNAME);	s->type = type;	s->value = islocal(type) ? MAXOFF : 0;	return;}/* *	return base of symbol storage and number of symbols */Sym*objbase(long *n){	*n = nsym;	return sym;}/* *	return i-th Symbol */Sym*objsym(int index){	if (!sym)		return 0;	if (index < 0 || index >= nsym)		return 0;	return sym+index;} /* * update the offset information for a 'a' or 'p' symbol in an intermediate file */void_offset(int id, long off){	Sym *s;		s = &sym[names[id]];	if (s->name[0] && islocal(s->type) && s->value > off)		s->value = off;} /* * update the type of a global text or data symbol */static int objupdate(int id, int type){	Sym *s; 	s = &sym[names[id]];	if (s->name[0])		if (s->type == 'U') {			s->type = type;			return 1;		} else if (s->type == 'b' || s->type == tolower(type)) {			s->type = tolower(type);			return 1;		} else if (s->type == type)			return 1;	return 0;} /* * 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<NNAME && a.name[i] != ' '; i++)		buf[i] = a.name[i];	buf[i] = 0;	arsize = atol(a.size);	if (arsize&1)		arsize++;	return arsize + SAR_HDR;} /* * make sure the symbol array can hold n elements; * expand it if it can't. */static voidassure(int n){	int old; 	if(n >= have){		old = have;		have = (n + CHUNK-1) &~ (CHUNK-1);		sym = realloc(sym, have * sizeof(*sym));		if(sym == 0){			fprint(2, "%s: out of memory\n");			exits("memory");		}		memset(sym + old, 0, (have - old) * sizeof(*sym));	}} voidobjreset(void){	if (sym) {		nsym = 0;		memset(names, 0, sizeof names);		memset(sym, 0, have * sizeof(*sym));	}}