ref: 6d5cccdbfa78d757b07efa64195f49a5db7e46e1
dir: /src/cmd/ld.c/
static char sccsid[] = "@(#) ./ld/main.c";
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <scc/mach.h>
#include <scc/scc.h>
#include <scc/ar.h>
#include <scc/syslibs.h>
#define NR_SYMBOL 128
typedef struct objlst Objlst;
typedef struct symbol Symbol;
typedef struct section Section;
enum {
NOINSTALL,
INSTALL,
};
enum {
OUTLIB,
INLIB,
};
struct section {
char *name;
unsigned long long size;
FILE *fp;
Section *next;
};
struct objlst {
Obj *obj;
struct objlst *next;
};
struct symbol {
char *name;
Obj *obj;
Objsym *def;
unsigned long long size, value;
struct symbol *next, *prev;
struct symbol *hash;
};
char *output = "a.out", *entry = "start", *datasiz;
static Section *sections;
static int bintype = -1;
static char *filename, *membname;
static Objlst *objhead, *objlast;
static Symbol *symtab[NR_SYMBOL];
static Symbol refhead = {
.next = &refhead,
.prev = &refhead,
};
static int sflag; /* discard all the symbols */
static int xflag; /* discard local symbols */
static int Xflag; /* discard locals starting with 'L' */
static int rflag; /* preserve relocation bits */
static int dflag; /* define common even with rflag */
static int gflag; /* preserve debug symbols */
static int status;
static char *
errstr(void)
{
return strerror(errno);
}
static void
error(char *fmt, ...)
{
va_list va;
va_start(va, fmt);
fprintf(stderr, "ld: %s: ", filename);
if (membname)
fprintf(stderr, "%s: ", membname);
vfprintf(stderr, fmt, va);
putc('\n', stderr);
va_end(va);
status = EXIT_FAILURE;
}
static void
cleanup(void)
{
if (status != EXIT_FAILURE)
remove(output);
}
static int
moreundef(void)
{
return refhead.next != &refhead;
}
static Symbol *
lookup(char *name, int install)
{
size_t len;
char *s;
unsigned h;
Symbol *sym;
h = genhash(name) % NR_SYMBOL;
for (sym = symtab[h]; sym; sym = sym->hash) {
if (!strcmp(name, sym->name))
return sym;
}
if (!install)
return NULL;
len = strlen(name) + 1;
sym = malloc(sizeof(*sym));
s = malloc(len);
if (!len || !s) {
error("out of memory");
exit(EXIT_FAILURE);
}
sym->obj = NULL;
sym->name = memcpy(s, name, len);
sym->hash = symtab[h];
symtab[h] = sym;
sym->value = 0;
sym->size = 0;
refhead.next->prev = sym;
sym->next = refhead.next;
refhead.next = sym;
sym->prev = &refhead;
return sym;
}
static Symbol *
define(Objsym *osym, Obj *obj)
{
Symbol *sym = lookup(osym->name, INSTALL);
if (sym->def && sym->def->type != 'C') {
error("%s: symbol redefined", osym->name);
return NULL;
}
sym->obj = obj;
sym->def = osym;
sym->size = osym->size;
sym->value = osym->value;
sym->next->prev = sym->prev;
sym->prev->next = sym->next;
sym->next = sym->prev = NULL;
return sym;
}
static int
newsym(Objsym *osym, Obj *obj)
{
Symbol *sym;
switch (osym->type) {
case 'U':
lookup(osym->name, INSTALL);
case '?':
case 'N':
break;
case 'C':
sym = lookup(osym->name, NOINSTALL);
if (!sym || !sym->def) {
define(osym, obj);
break;
}
if (sym->def->type != 'C')
break;
if (sym->size < osym->size)
sym->size = osym->size;
break;
default:
if (isupper(osym->type))
define(osym, obj);
break;
}
return 1;
}
static void
newsect(Objsect *secp, FILE *fp)
{
int c;
unsigned long long align, size;
Section *sp;
for (sp = sections; sp; sp = sp->next) {
if (!strcmp(sp->name, secp->name))
break;
}
if (!sp) {
size_t len = strlen(secp->name) + 1;
char * s = malloc(len);
FILE *fp = tmpfile();
sp = malloc(sizeof(*sp));
if (!s || !sp || !fp)
goto err;
sp->name = memcpy(s, secp->name, len);
sp->size = 0;
sp->fp = fp;
sp->next = sections;
if (!sections)
sections = sp;
}
align = secp->align-1;
size = (sp->size + align) & ~align;
for (; secp->size < size; secp->size++)
putc(0, sp->fp);
fseek(fp, secp->offset, SEEK_SET);
while ((c = getc(fp)) != EOF)
putc(c, sp->fp);
fflush(sp->fp);
if (!ferror(fp) && !ferror(sp->fp))
return;
err:
error(errstr());
}
static void
loadobj(Obj *obj, FILE *fp)
{
int n;
Objlst *lst;
Objsym *sym;
Objsect *secp;
if ((lst = malloc(sizeof(*lst))) == NULL) {
error("out of memory");
return;
}
if (objsect(obj) < 0 || objsyms(obj) < 0)
goto err1;
lst->obj = obj;
lst->next = NULL;
if (!objlast)
objlast = objhead = lst;
else
objlast = objlast->next = lst;
for (sym = obj->syms; sym; sym = sym->next)
newsym(sym, obj);
for (secp = obj->secs; secp; secp = secp->next)
newsect(secp, fp);
return;
err1:
free(lst);
error("out of memory");
}
static void
newobject(FILE *fp, int type, int inlib)
{
Obj *obj;
Symbol *sym, *p;
if ((obj = objnew(type)) == NULL) {
error("out of memory");
return;
}
if (bintype == -1) {
bintype = type;
} else if (bintype != type) {
error("not compatible object file");
return;
}
bintype = type;
if (objread(obj, fp) < 0) {
error("object file corrupted");
goto delete;
}
if (inlib) {
p = &refhead;
for (sym = p->next; sym != p; sym = sym->next) {
if (objlookup(obj, sym->name, 0))
break;
}
if (sym == p)
goto delete;
}
loadobj(obj, fp);
return;
delete:
objdel(obj);
return;
}
static void
loadlib(FILE *fp)
{
int t, loaded;
long n;
Objsymdef *def, *dp;
Symbol *sym;
if (getindex(bintype, &n, &def, fp) < 0) {
error("corrupted index");
return;
}
for (loaded = 0; moreundef(); loaded = 0) {
for (dp = def; dp; dp = dp->next) {
sym = lookup(dp->name, NOINSTALL);
if (!sym || !sym->def)
continue;
if (fseek(fp, dp->offset, SEEK_SET) == EOF) {
error(errstr());
break;
}
if ((t = objtype(fp, NULL)) == -1) {
error("library file corrupted");
break;
}
if (t != bintype) {
error("incompatible library");
break;
}
newobject(fp, t, OUTLIB);
loaded = 1;
}
if (!loaded)
break;
}
clean:
free(def);
}
static int
newmember(FILE *fp, char *name, void *data)
{
int t;
int *nmemb = data;
membname = data;
if (bintype == -1) {
error("an object file is needed before any library");
return 0;
}
if (*nmemb++ == 0) {
if (!strncmp(name, "/", SARNAM) ||
!strncmp(name, "__.SYMDEF", SARNAM)) {
loadlib(fp);
return 0;
}
}
if ((t = objtype(fp, NULL)) == -1)
return 1;
if (bintype != t) {
error("wrong object file format");
return 1;
}
newobject(fp, t, INLIB);
return 1;
}
static int
newlibrary(FILE *fp)
{
int nmemb = 0;
return formember(fp, newmember, &nmemb);
}
static FILE *
openfile(char *name, char *buffer)
{
size_t pathlen, len;
FILE *fp;
char **bp, **base, **end;
char libname[FILENAME_MAX];
filename = name;
membname = NULL;
if (name[0] != '-' || name[1] != 'l') {
if ((fp = fopen(name, "rb")) == NULL)
error(errstr());
return fp;
}
len = strlen(name+2) + 3;
if (len > FILENAME_MAX-1) {
error("library name too long");
return NULL;
}
strcat(strcpy(buffer, "lib"), name+2);
filename = buffer;
if ((fp = fopen(libname, "rb")) != NULL)
return fp;
base = syslibs;
end = &syslibs[MAX_LIB_PATHS];
for (bp = base; bp < end && *bp; ++bp) {
pathlen = strlen(*bp);
if (pathlen + len > FILENAME_MAX-1)
continue;
memcpy(libname, *bp, pathlen);
memcpy(libname+pathlen+1, buffer, len);
buffer[pathlen] = '/';
if ((fp = fopen(buffer, "rb")) != NULL)
return fp;
}
error("not found");
return NULL;
}
static void
pass1(int argc, char *argv[])
{
int t;
FILE *fp;
char buff[FILENAME_MAX];
for ( ; *argv; ++argv) {
if ((fp = openfile(*argv, buff)) == NULL)
continue;
if ((t = objtype(fp, NULL)) != -1)
newobject(fp, t, OUTLIB);
else if (archive(fp))
newlibrary(fp);
else
error("bad format");
fclose(fp);
}
if (moreundef()) {
Symbol *sym, *p;
p = &refhead;
for (sym = p->next; sym != p; sym = sym->next) {
fprintf(stderr,
"ld: symbol '%s' not defined\n",
sym->name);
}
exit(EXIT_FAILURE);
}
}
static void
pass2(int argc, char *argv[])
{
}
static void
usage(void)
{
fputs("usage: ld [options] file ...\n", stderr);
exit(EXIT_FAILURE);
}
static void
Lpath(char *path)
{
char **bp, **base, **end;
base = syslibs;
end = &syslibs[MAX_LIB_PATHS];
for (bp = base; bp < end && *bp; ++bp)
;
if (bp == end) {
fputs("ld: too many -L options\n", stderr);
exit(1);
}
*bp = path;
}
int
main(int argc, char *argv[])
{
char *cp, **p;
for (--argc; *++argv; --argc) {
if (argv[0][0] != '-' || argv[0][1] == 'l')
break;
if (argv[0][1] == '-') {
--argc, ++argv;
break;
}
for (cp = &argv[0][1]; *cp; ++cp) {
switch (*cp) {
case 's':
sflag = 1;
break;
case 'x':
xflag = 1;
break;
case 'X':
Xflag = 1;
break;
case 'r':
rflag = 1;
break;
case 'd':
dflag = 1;
break;
case 'i':
case 'n':
/* TODO */
break;
case 'L':
if (argc == 0)
goto usage;
++argv, --argc;
Lpath(*argv);
break;
case 'u':
if (argc == 0)
goto usage;
++argv, --argc;
lookup(*argv, INSTALL);
break;
case 'o':
if (argc == 0)
goto usage;
++argv, --argc;
output = *argv;
break;
case 'e':
if (argc == 0)
goto usage;
++argv, --argc;
entry = *argv;
break;
case 'D':
if (argc == 0)
goto usage;
++argv, --argc;
datasiz = *argv;
break;
default:
usage:
usage();
}
}
}
if (argc == 0)
usage();
atexit(cleanup);
pass1(argc, argv);
pass2(argc, argv);
return status;
}