xref: /plan9-contrib/sys/src/cmd/ld/pobj.c (revision 40d015479ed36701ae6dcfd8814f849fc6285e8d)

#include	"l.h"
#include	<ar.h>

char	*noname		= "<none>";
char	symname[]	= SYMDEF;

char**	libdir;
int	nlibdir	= 0;
static	int	maxlibdir = 0;

int
isobjfile(char *f)
{
	int n, v;
	Biobuf *b;
	char buf1[5], buf2[SARMAG];

	b = Bopen(f, OREAD);
	if(b == nil)
		return 0;
	n = Bread(b, buf1, 5);
	if(n == 5 && (buf1[2] == 1 && buf1[3] == '<' || buf1[3] == 1 && buf1[4] == '<'))
		v = 1;	/* good enough for our purposes */
	else{
		Bseek(b, 0, 0);
		n = Bread(b, buf2, SARMAG);
		v = n == SARMAG && strncmp(buf2, ARMAG, SARMAG) == 0;
	}
	Bterm(b);
	return v;
}

void
loadlib(void)
{
	int i;
	long h;
	Sym *s;

loop:
	xrefresolv = 0;
	for(i=0; i<libraryp; i++) {
		if(debug['v'])
			Bprint(&bso, "%5.2f autolib: %s (from %s)\n", cputime(), library[i], libraryobj[i]);
		objfile(library[i]);
	}
	if(xrefresolv)
	for(h=0; h<nelem(hash); h++)
	for(s = hash[h]; s != S; s = s->link)
		if(s->type == SXREF)
			goto loop;
}

void
objfile(char *file)
{
	long off, esym, cnt, l;
	int f, work;
	Sym *s;
	char magbuf[SARMAG];
	char name[LIBNAMELEN], pname[LIBNAMELEN];
	struct ar_hdr arhdr;
	char *e, *start, *stop;

	if(debug['v'])
		Bprint(&bso, "%5.2f ldobj: %s\n", cputime(), file);
	Bflush(&bso);
	if(file[0] == '-' && file[1] == 'l') {
		snprint(pname, sizeof(pname), "lib%s.a", file+2);
		e = findlib(pname);
		if(e == nil) {
			diag("cannot find library: %s", file);
			errorexit();
		}
		snprint(name, sizeof(name), "%s/%s", e, pname);
		file = name;
	}
	f = open(file, 0);
	if(f < 0) {
		diag("cannot open %s: %r", file);
		errorexit();
	}
	l = read(f, magbuf, SARMAG);
	if(l != SARMAG || strncmp(magbuf, ARMAG, SARMAG)){
		/* load it as a regular file */
		l = seek(f, 0L, 2);
		seek(f, 0L, 0);
		ldobj(f, l, file);
		close(f);
		return;
	}

	if(debug['v'])
		Bprint(&bso, "%5.2f ldlib: %s\n", cputime(), file);
	l = read(f, &arhdr, SAR_HDR);
	if(l != SAR_HDR) {
		diag("%s: short read on archive file symbol header", file);
		goto out;
	}
	if(strncmp(arhdr.name, symname, strlen(symname))) {
		diag("%s: first entry not symbol header", file);
		goto out;
	}

	esym = SARMAG + SAR_HDR + atolwhex(arhdr.size);
	off = SARMAG + SAR_HDR;

	/*
	 * just bang the whole symbol file into memory
	 */
	seek(f, off, 0);
	cnt = esym - off;
	start = malloc(cnt + 10);
	cnt = read(f, start, cnt);
	if(cnt <= 0){
		close(f);
		return;
	}
	stop = &start[cnt];
	memset(stop, 0, 10);

	work = 1;
	while(work){
		if(debug['v'])
			Bprint(&bso, "%5.2f library pass: %s\n", cputime(), file);
		Bflush(&bso);
		work = 0;
		for(e = start; e < stop; e = strchr(e+5, 0) + 1) {
			s = lookup(e+5, 0);
			if(s->type != SXREF)
				continue;
			sprint(pname, "%s(%s)", file, s->name);
			if(debug['v'])
				Bprint(&bso, "%5.2f library: %s\n", cputime(), pname);
			Bflush(&bso);
			l = e[1] & 0xff;
			l |= (e[2] & 0xff) << 8;
			l |= (e[3] & 0xff) << 16;
			l |= (e[4] & 0xff) << 24;
			seek(f, l, 0);
			l = read(f, &arhdr, SAR_HDR);
			if(l != SAR_HDR)
				goto bad;
			if(strncmp(arhdr.fmag, ARFMAG, sizeof(arhdr.fmag)))
				goto bad;
			l = atolwhex(arhdr.size);
			ldobj(f, l, pname);
			if(s->type == SXREF) {
				diag("%s: failed to load: %s", file, s->name);
				errorexit();
			}
			work = 1;
			xrefresolv = 1;
		}
	}
	return;

bad:
	diag("%s: bad or out of date archive", file);
out:
	close(f);
}

void
addlibpath(char *arg)
{
	char **p;

	if(nlibdir >= maxlibdir) {
		if(maxlibdir == 0)
			maxlibdir = 8;
		else
			maxlibdir *= 2;
		p = malloc(maxlibdir*sizeof(*p));
		if(p == nil) {
			diag("out of memory");
			errorexit();
		}
		memmove(p, libdir, nlibdir*sizeof(*p));
		free(libdir);
		libdir = p;
	}
	libdir[nlibdir++] = strdup(arg);
}

char*
findlib(char *file)
{
	int i;
	char name[LIBNAMELEN];

	for(i = 0; i < nlibdir; i++) {
		snprint(name, sizeof(name), "%s/%s", libdir[i], file);
		if(fileexists(name))
			return libdir[i];
	}
	return nil;
}

void
addlibroot(void)
{
	char *a;
	char name[LIBNAMELEN];

	a = getenv("ccroot");
	if(a != nil && *a != '\0') {
		if(!fileexists(a)) {
			diag("nonexistent $ccroot: %s", a);
			errorexit();
		}
	}else
		a = "";
	snprint(name, sizeof(name), "%s/%s/lib", a, thestring);
	addlibpath(name);
}

void
addlib(char *obj)
{
	char fn1[LIBNAMELEN], fn2[LIBNAMELEN], comp[LIBNAMELEN], *p, *name;
	int i, search;

	if(histfrogp <= 0)
		return;

	name = fn1;
	search = 0;
	if(histfrog[0]->name[1] == '/') {
		sprint(name, "");
		i = 1;
	} else if(histfrog[0]->name[1] == '.') {
		sprint(name, ".");
		i = 0;
	} else {
		sprint(name, "");
		i = 0;
		search = 1;
	}

	for(; i<histfrogp; i++) {
		snprint(comp, sizeof comp, histfrog[i]->name+1);
		for(;;) {
			p = strstr(comp, "$O");
			if(p == 0)
				break;
			memmove(p+1, p+2, strlen(p+2)+1);
			p[0] = thechar;
		}
		for(;;) {
			p = strstr(comp, "$M");
			if(p == 0)
				break;
			if(strlen(comp)+strlen(thestring)-2+1 >= sizeof comp) {
				diag("library component too long");
				return;
			}
			memmove(p+strlen(thestring), p+2, strlen(p+2)+1);
			memmove(p, thestring, strlen(thestring));
		}
		if(strlen(fn1) + strlen(comp) + 3 >= sizeof(fn1)) {
			diag("library component too long");
			return;
		}
		if(i > 0 || !search)
			strcat(fn1, "/");
		strcat(fn1, comp);
	}

	cleanname(name);

	if(search){
		p = findlib(name);
		if(p != nil){
			snprint(fn2, sizeof(fn2), "%s/%s", p, name);
			name = fn2;
		}
	}

	for(i=0; i<libraryp; i++)
		if(strcmp(name, library[i]) == 0)
			return;
	if(libraryp == nelem(library)){
		diag("too many autolibs; skipping %s", name);
		return;
	}

	p = malloc(strlen(name) + 1);
	strcpy(p, name);
	library[libraryp] = p;
	p = malloc(strlen(obj) + 1);
	strcpy(p, obj);
	libraryobj[libraryp] = p;
	libraryp++;
}

void
addhist(long line, int type)
{
	Auto *u;
	Sym *s;
	int i, j, k;

	u = malloc(sizeof(Auto));
	s = malloc(sizeof(Sym));
	s->name = malloc(2*(histfrogp+1) + 1);

	u->asym = s;
	u->type = type;
	u->aoffset = line;
	u->link = curhist;
	curhist = u;

	j = 1;
	for(i=0; i<histfrogp; i++) {
		k = histfrog[i]->value;
		s->name[j+0] = k>>8;
		s->name[j+1] = k;
		j += 2;
	}
}

void
histtoauto(void)
{
	Auto *l;

	while((l = curhist) != nil) {
		curhist = l->link;
		l->link = curauto;
		curauto = l;
	}
}

void
collapsefrog(Sym *s)
{
	int i;

	/*
	 * bad encoding of path components only allows
	 * MAXHIST components. if there is an overflow,
	 * first try to collapse xxx/..
	 */
	for(i=1; i<histfrogp; i++)
		if(strcmp(histfrog[i]->name+1, "..") == 0) {
			memmove(histfrog+i-1, histfrog+i+1,
				(histfrogp-i-1)*sizeof(histfrog[0]));
			histfrogp--;
			goto out;
		}

	/*
	 * next try to collapse .
	 */
	for(i=0; i<histfrogp; i++)
		if(strcmp(histfrog[i]->name+1, ".") == 0) {
			memmove(histfrog+i, histfrog+i+1,
				(histfrogp-i-1)*sizeof(histfrog[0]));
			goto out;
		}

	/*
	 * last chance, just truncate from front
	 */
	memmove(histfrog+0, histfrog+1,
		(histfrogp-1)*sizeof(histfrog[0]));

out:
	histfrog[histfrogp-1] = s;
}

uchar*
readsome(int f, uchar *buf, uchar *good, uchar *stop, int max)
{
	int n;

	n = stop - good;
	memmove(buf, good, stop - good);
	stop = buf + n;
	n = MAXIO - n;
	if(n > max)
		n = max;
	n = read(f, stop, n);
	if(n <= 0)
		return 0;
	return stop + n;
}

Sym*
lookup(char *symb, int v)
{
	Sym *s;
	char *p;
	long h;
	int c, l;

	h = v;
	for(p=symb; c = *p; p++)
		h = h+h+h + c;
	l = (p - symb) + 1;
	if(h < 0)
		h = ~h;
	h %= NHASH;
	for(s = hash[h]; s != S; s = s->link)
		if(s->version == v)
		if(memcmp(s->name, symb, l) == 0)
			return s;

	s = halloc(sizeof(Sym));
	s->name = malloc(l + 1);
	memmove(s->name, symb, l);

	s->link = hash[h];
	s->type = 0;
	s->version = v;
	s->value = 0;
	s->sig = 0;
	hash[h] = s;
	return s;
}

int
find1(long l, int c)
{
	char *p;
	int i;

	p = (char*)&l;
	for(i=0; i<4; i++)
		if(*p++ == c)
			return i;
	return 0;
}

long
ieeedtof(Ieee *ieeep)
{
	int exp;
	long v;

	if(ieeep->h == 0)
		return 0;
	exp = (ieeep->h>>20) & ((1L<<11)-1L);
	exp -= (1L<<10) - 2L;
	v = (ieeep->h & 0xfffffL) << 3;
	v |= (ieeep->l >> 29) & 0x7L;
	if((ieeep->l >> 28) & 1) {
		v++;
		if(v & 0x800000L) {
			v = (v & 0x7fffffL) >> 1;
			exp++;
		}
	}
	if(exp <= -126 || exp >= 130)
		diag("double fp to single fp overflow");
	v |= ((exp + 126) & 0xffL) << 23;
	v |= ieeep->h & 0x80000000L;
	return v;
}

double
ieeedtod(Ieee *ieeep)
{
	Ieee e;
	double fr;
	int exp;

	if(ieeep->h & (1L<<31)) {
		e.h = ieeep->h & ~(1L<<31);
		e.l = ieeep->l;
		return -ieeedtod(&e);
	}
	if(ieeep->l == 0 && ieeep->h == 0)
		return 0;
	fr = ieeep->l & ((1L<<16)-1L);
	fr /= 1L<<16;
	fr += (ieeep->l>>16) & ((1L<<16)-1L);
	fr /= 1L<<16;
	fr += (ieeep->h & (1L<<20)-1L) | (1L<<20);
	fr /= 1L<<21;
	exp = (ieeep->h>>20) & ((1L<<11)-1L);
	exp -= (1L<<10) - 2L;
	return ldexp(fr, exp);
}