usr/src/usr.bin/strip/strip.c

/*
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1988 Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)strip.c     5.7 (Berkeley) 5/26/91";
#endif /* not lint */

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <a.out.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct exec EXEC;
typedef struct nlist NLIST;

void err __P((const char *fmt, ...));
void s_stab __P((const char *, int, EXEC *));
void s_sym __P((const char *, int, EXEC *));
void usage __P((void));

int eval;

main(argc, argv)
        int argc;
        char *argv[];
{
        register int fd, nb;
        EXEC head;
        void (*sfcn)__P((const char *, int, EXEC *));
        int ch;
        char *fn;

        sfcn = s_sym;
        while ((ch = getopt(argc, argv, "d")) != EOF)
                switch(ch) {
                case 'd':
                        sfcn = s_stab;
                        break;
                case '?':
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        while (fn = *argv++) {
                if ((fd = open(fn, O_RDWR)) < 0 ||
                    (nb = read(fd, &head, sizeof(EXEC))) == -1) {
                        err("%s: %s", fn, strerror(errno));
                        continue;
                }
                if (nb != sizeof(EXEC) || N_BADMAG(head)) {
                        err("%s: %s", fn, strerror(EFTYPE));
                        continue;
                }
                sfcn(fn, fd, &head);
                if (close(fd))
                        err("%s: %s", fn, strerror(errno));
        }
        exit(eval);
}

void
s_sym(fn, fd, ep)
        const char *fn;
        int fd;
        register EXEC *ep;
{
        static int pagesize = -1;
        register off_t fsize;

        /* If no symbols or data/text relocation info, quit. */
        if (!ep->a_syms && !ep->a_trsize && !ep->a_drsize)
                return;

        /*
         * New file size is the header plus text and data segments; OMAGIC
         * and NMAGIC formats have the text/data immediately following the
         * header.  ZMAGIC format wastes the rest of of header page.
         */
        if (ep->a_magic == ZMAGIC)
                fsize = pagesize == -1 ? (pagesize = getpagesize()) : pagesize;
        else
                fsize = sizeof(EXEC);
        fsize += ep->a_text + ep->a_data;

        /* Set symbol size and relocation info values to 0. */
        ep->a_syms = ep->a_trsize = ep->a_drsize = 0;

        /* Rewrite the header and truncate the file. */
        if (lseek(fd, 0L, SEEK_SET) == -1 ||
            write(fd, ep, sizeof(EXEC)) != sizeof(EXEC) ||
            ftruncate(fd, fsize))
                err("%s: %s", fn, strerror(errno));
}

void
s_stab(fn, fd, ep)
        const char *fn;
        int fd;
        EXEC *ep;
{
        struct stat sb;
        register NLIST *bsym2, *sym1, *sym2;
        register u_long nsym1, nsym2;
        register char *p, *bstr2, *str1, *str2;
        register int len, symlen;
        off_t fsize;
        int nb;
        char *bp;

        /* Quit if no symbols. */
        if (ep->a_syms == 0)
                return;

        bsym2 = NULL;
        bp = bstr2 = NULL;

        /* Read the file into memory.                   XXX mmap */
        if (fstat(fd, &sb))
                goto syserr;
        if ((bp = malloc(sb.st_size)) == NULL)
                goto syserr;
        if (lseek(fd, 0L, SEEK_SET) == -1)
                goto syserr;
        if ((nb = read(fd, bp, (int)sb.st_size)) == -1)
                goto syserr;
        if (nb != sb.st_size) {
                errno = EIO;
                goto syserr;
        }

        /*
         * Allocate space for new symbol and string tables.  Allocate before
         * reading the symbol tables so we can do it all in a single pass.
         * This loses if there weren't any symbols to strip, but that's life.
         */
        sym1 = (NLIST *)(bp + N_SYMOFF(*ep));
        if ((bsym2 = sym2 = malloc((u_int)ep->a_syms)) == NULL) {
                err("%s", strerror(errno));
                goto mem;
        }
        str1 = bp + N_STROFF(*ep);
        if ((bstr2 = malloc((u_int)*(u_long *)str1)) == NULL) {
                err("%s", strerror(errno));
                goto mem;
        }
        str2 = bstr2 + sizeof(u_long);
        symlen = sizeof(u_long);

        /*
         * Read through the symbol table.  For each non-debugging symbol,
         * copy it into the new symbol and string tables.  Keep track of
         * how many symbols are copied and the length of the new string
         * table.
         */
#define strx    n_un.n_strx
        nsym2 = 0;
        for (nsym1 = ep->a_syms / sizeof(NLIST); nsym1--; ++sym1)
                if (!(sym1->n_type & N_STAB) && sym1->strx) {
                        *sym2 = *sym1;
                        sym2->strx = str2 - bstr2;
                        p = str1 + sym1->strx;
                        len = strlen(p) + 1;
                        bcopy(p, str2, len);
                        symlen += len;
                        str2 += len;
                        ++sym2;
                        ++nsym2;
                }

        /* If no debugging symbols, quit. */
        if (!nsym2)
                goto mem;

        /* Fill in new symbol table size. */
        ep->a_syms = nsym2 * sizeof(NLIST);

        /* Write out the header. */
        if (lseek(fd, 0L, SEEK_SET) == -1 ||
            write(fd, ep, sizeof(EXEC)) != sizeof(EXEC))
                goto syserr;

        /* Write out the symbol table. */
        if (lseek(fd, N_SYMOFF(*ep), SEEK_SET) == -1 ||
            write(fd, bsym2, ep->a_syms) != ep->a_syms)
                goto syserr;

        /* Fill in the new size of the string table. */
        *(u_long *)bstr2 = symlen;

        /* Write out the string table. */
        if (write(fd, bstr2, symlen) != symlen)
                goto syserr;

        /* Truncate to the current length. */
        if ((fsize = lseek(fd, 0L, SEEK_CUR)) == -1)
                goto syserr;
        if (ftruncate(fd, fsize))
syserr:         err("%s: %s", fn, strerror(errno));

mem:    if (bp)
                free(bp);
        if (bstr2)
                free(bstr2);
        if (bsym2)
                free(bsym2);
}

void
usage()
{

        (void)fprintf(stderr, "usage: strip [-d] file ...\n");
        exit(1);
}

#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

void
#if __STDC__
err(const char *fmt, ...)
#else
err(fmt, va_alist)
        char *fmt;
        va_dcl
#endif
{
        va_list ap;
#if __STDC__
        va_start(ap, fmt);
#else
        va_start(ap);
#endif
        (void)fprintf(stderr, "strip: ");
        (void)vfprintf(stderr, fmt, ap);
        va_end(ap);
        (void)fprintf(stderr, "\n");
        eval = 1;
}