Return to nm.c CVS log

Up to [local] / src / usr.bin / nm

Fixes endianess problems with old a.out tools. This makes building
some cross toolchains possible.

This also changes some utilities's behavior slightly:
- nm, strip, size now handle any a.out format they know about.
- ranlib complains if it detects mixed archives (several object
formats for different boxes).

In the presence of mixed objects, you still have file, ranlib or ld
to prevent you from getting too confused...

/*	$OpenBSD: nm.c,v 1.8 1999/05/10 16:14:07 espie Exp $	*/
/*	$NetBSD: nm.c,v 1.7 1996/01/14 23:04:03 pk Exp $	*/

/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Hans Huebner.
 *
 * 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
static char copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)nm.c	8.1 (Berkeley) 6/6/93";
#endif
static char rcsid[] = "$OpenBSD: nm.c,v 1.8 1999/05/10 16:14:07 espie Exp $";
#endif /* not lint */

#include <sys/param.h>
#include <sys/types.h>
#include <a.out.h>
#include <stab.h>
#include <ar.h>
#include <ranlib.h>
#include <unistd.h>
#include <err.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* XXX get shared code to handle byte-order swaps */
#include "byte.c"


int ignore_bad_archive_entries = 1;
int print_only_external_symbols;
int print_only_undefined_symbols;
int print_all_symbols;
int print_file_each_line;
int fcount;

int rev;
int fname(), rname(), value();
int (*sfunc)() = fname;


/* some macros for symbol type (nlist.n_type) handling */
#define	IS_DEBUGGER_SYMBOL(x)	((x) & N_STAB)
#define	IS_EXTERNAL(x)		((x) & N_EXT)
#define	SYMBOL_TYPE(x)		((x) & (N_TYPE | N_STAB))

void *emalloc(), *erealloc();

/*
 * main()
 *	parse command line, execute process_file() for each file
 *	specified on the command line.
 */
main(argc, argv)
	int argc;
	char **argv;
{
	extern int optind;
	int ch, errors;

	while ((ch = getopt(argc, argv, "agnopruw")) != -1) {
		switch (ch) {
		case 'a':
			print_all_symbols = 1;
			break;
		case 'g':
			print_only_external_symbols = 1;
			break;
		case 'n':
			sfunc = value;
			break;
		case 'o':
			print_file_each_line = 1;
			break;
		case 'p':
			sfunc = NULL;
			break;
		case 'r':
			rev = 1;
			break;
		case 'u':
			print_only_undefined_symbols = 1;
			break;
		case 'w':
			ignore_bad_archive_entries = 0;
			break;
		case '?':
		default:
			usage();
		}
	}
	fcount = argc - optind;
	argv += optind;

	if (rev && sfunc == fname)
		sfunc = rname;

	if (!fcount)
		errors = process_file("a.out");
	else {
		errors = 0;
		do {
			errors |= process_file(*argv);
		} while (*++argv);
	}
	exit(errors);
}

/*
 * process_file()
 *	show symbols in the file given as an argument.  Accepts archive and
 *	object files as input.
 */
process_file(fname)
	char *fname;
{
	struct exec exec_head;
	FILE *fp;
	int retval;
	char magic[SARMAG];
    
	if (!(fp = fopen(fname, "r"))) {
		warn("cannot read %s", fname);
		return(1);
	}

	if (fcount > 1)
		(void)printf("\n%s:\n", fname);
    
	/*
	 * first check whether this is an object file - read a object
	 * header, and skip back to the beginning
	 */
	if (fread((char *)&exec_head, sizeof(exec_head), (size_t)1, fp) != 1) {
		warnx("%s: bad format", fname);
		(void)fclose(fp);
		return(1);
	}
	rewind(fp);

	if (BAD_OBJECT(exec_head)) {
	/* this could be an archive */
		if (fread(magic, sizeof(magic), (size_t)1, fp) != 1 ||
		    strncmp(magic, ARMAG, SARMAG)) {
			warnx("%s: not object file or archive", fname);
			(void)fclose(fp);
			return(1);
		}
		retval = show_archive(fname, fp);
	} else
		retval = show_objfile(fname, fp);
	(void)fclose(fp);
	return(retval);
}

/*
 * show_archive()
 *	show symbols in the given archive file
 */
show_archive(fname, fp)
	char *fname;
	FILE *fp;
{
	struct ar_hdr ar_head;
	struct exec exec_head;
	int i, rval;
	long last_ar_off;
	char *p, *name;
	int baselen, namelen;

	baselen = strlen(fname) + 3;
	namelen = sizeof(ar_head.ar_name);
	name = emalloc(baselen + namelen);

	rval = 0;

	/* while there are more entries in the archive */
	while (fread((char *)&ar_head, sizeof(ar_head), (size_t)1, fp) == 1) {
		/* bad archive entry - stop processing this archive */
		if (strncmp(ar_head.ar_fmag, ARFMAG, sizeof(ar_head.ar_fmag))) {
			warnx("%s: bad format archive header", fname);
			(void)free(name);
			return(1);
		}

		/* remember start position of current archive object */
		last_ar_off = ftell(fp);

		/* skip ranlib entries */
		if (!strncmp(ar_head.ar_name, RANLIBMAG, sizeof(RANLIBMAG) - 1))
			goto skip;

		/*
		 * construct a name of the form "archive.a:obj.o:" for the
		 * current archive entry if the object name is to be printed
		 * on each output line
		 */
		p = name;
		if (print_file_each_line)
			p += sprintf(p, "%s:", fname);
#ifdef AR_EFMT1
		/*
		 * BSD 4.4 extended AR format: #1/<namelen>, with name as the
		 * first <namelen> bytes of the file
		 */
		if (		(ar_head.ar_name[0] == '#') &&
				(ar_head.ar_name[1] == '1') &&
				(ar_head.ar_name[2] == '/') && 
				(isdigit(ar_head.ar_name[3]))) {

			int len = atoi(&ar_head.ar_name[3]);
			if (len > namelen) {
				p -= (long)name;
				name = (char *)erealloc(name, baselen+len);
				namelen = len;
				p += (long)name;
			}
			if (fread(p, len, 1, fp) != 1) {
				warnx("%s: premature EOF", name);
				(void)free(name);
				return 1;
			}
			p += len;
		} else
#endif
		for (i = 0; i < sizeof(ar_head.ar_name); ++i)
			if (ar_head.ar_name[i] && ar_head.ar_name[i] != ' ')
				*p++ = ar_head.ar_name[i];
		*p++ = '\0';

		/* get and check current object's header */
		if (fread((char *)&exec_head, sizeof(exec_head),
		    (size_t)1, fp) != 1) {
			warnx("%s: premature EOF", name);
			(void)free(name);
			return(1);
		}

		if (BAD_OBJECT(exec_head)) {
			if (!ignore_bad_archive_entries) {
				 warnx("%s: bad format", name);
				rval = 1;
			}
		} else {
			(void)fseek(fp, (long)-sizeof(exec_head), SEEK_CUR);
			if (!print_file_each_line)
				(void)printf("\n%s:\n", name);
			rval |= show_objfile(name, fp);
		}

		/*
		 * skip to next archive object - it starts at the next
	 	 * even byte boundary
		 */
#define even(x) (((x) + 1) & ~1)
skip:		if (fseek(fp, last_ar_off + even(atol(ar_head.ar_size)),
		    SEEK_SET)) {
			warn("%s", fname);
			(void)free(name);
			return(1);
		}
	}
	(void)free(name);
	return(rval);
}

/*
 * show_objfile()
 *	show symbols from the object file pointed to by fp.  The current
 *	file pointer for fp is expected to be at the beginning of an a.out
 *	header.
 */
show_objfile(objname, fp)
	char *objname;
	FILE *fp;
{
	register struct nlist *names, *np;
	register int i, nnames, nrawnames;
	struct exec head;
	long stabsize;
	char *stab;

	/* read a.out header */
	if (fread((char *)&head, sizeof(head), (size_t)1, fp) != 1) {
		warnx("%s: cannot read header", objname);
		return(1);
	}

	/*
	 * skip back to the header - the N_-macros return values relative
	 * to the beginning of the a.out header
	 */
	if (fseek(fp, (long)-sizeof(head), SEEK_CUR)) {
		warn("%s", objname);
		return(1);
	}

	/* stop if this is no valid object file, or a format we don't dare
	 * playing with
	 */
	if (BAD_OBJECT(head)) {
		warnx("%s: bad format", objname);
		return(1);
	}

	fix_header_order(&head);

	/* stop if the object file contains no symbol table */
	if (!head.a_syms) {
		warnx("%s: no name list", objname);
		return(1);
	}

	if (fseek(fp, (long)N_SYMOFF(head), SEEK_CUR)) {
		warn("%s", objname);
		return(1);
	}

	/* get memory for the symbol table */
	names = emalloc((size_t)head.a_syms);
	nrawnames = head.a_syms / sizeof(*names);
	if (fread((char *)names, (size_t)head.a_syms, (size_t)1, fp) != 1) {
		warnx("%s: cannot read symbol table", objname);
		(void)free((char *)names);
		return(1);
	}
	fix_nlists_order(names, nrawnames, N_GETMID(head));

	/*
	 * Following the symbol table comes the string table.  The first
	 * 4-byte-integer gives the total size of the string table
	 * _including_ the size specification itself.
	 */
	if (fread((char *)&stabsize, sizeof(stabsize), (size_t)1, fp) != 1) {
		warnx("%s: cannot read stab size", objname);
		(void)free((char *)names);
		return(1);
	}
	stabsize = fix_long_order(stabsize, N_GETMID(head));
	stab = emalloc((size_t)stabsize);

	/*
	 * read the string table offset by 4 - all indices into the string
	 * table include the size specification.
	 */
	stabsize -= 4;		/* we already have the size */
	if (fread(stab + 4, (size_t)stabsize, (size_t)1, fp) != 1) {
		warnx("%s: stab truncated..", objname);
		(void)free((char *)names);
		(void)free(stab);
		return(1);
	}

	/*
	 * fix up the symbol table and filter out unwanted entries
	 *
	 * common symbols are characterized by a n_type of N_UNDF and a
	 * non-zero n_value -- change n_type to N_COMM for all such
	 * symbols to make life easier later.
	 *
	 * filter out all entries which we don't want to print anyway
	 */
	for (np = names, i = nnames = 0; i < nrawnames; np++, i++) {
		if (SYMBOL_TYPE(np->n_type) == N_UNDF && np->n_value)
			np->n_type = N_COMM | (np->n_type & N_EXT);
		if (!print_all_symbols && IS_DEBUGGER_SYMBOL(np->n_type))
			continue;
		if (print_only_external_symbols && !IS_EXTERNAL(np->n_type))
			continue;
		if (print_only_undefined_symbols &&
		    SYMBOL_TYPE(np->n_type) != N_UNDF)
			continue;

		/*
		 * make n_un.n_name a character pointer by adding the string
		 * table's base to n_un.n_strx
		 *
		 * don't mess with zero offsets
		 */
		if (np->n_un.n_strx)
			np->n_un.n_name = stab + np->n_un.n_strx;
		else
			np->n_un.n_name = "";
		names[nnames++] = *np;
	}

	/* sort the symbol table if applicable */
	if (sfunc)
		qsort((char *)names, (size_t)nnames, sizeof(*names), sfunc);

	/* print out symbols */
	for (np = names, i = 0; i < nnames; np++, i++)
		print_symbol(objname, np);

	(void)free((char *)names);
	(void)free(stab);
	return(0);
}

/*
 * print_symbol()
 *	show one symbol
 */
print_symbol(objname, sym)
	char *objname;
	register struct nlist *sym;
{
	char *typestring(), typeletter();

	if (print_file_each_line)
		(void)printf("%s:", objname);

	/*
	 * handle undefined-only format seperately (no space is
	 * left for symbol values, no type field is printed)
	 */
	if (print_only_undefined_symbols) {
		(void)puts(sym->n_un.n_name);
		return;
	}

	/* print symbol's value */
	if (SYMBOL_TYPE(sym->n_type) == N_UNDF)
		(void)printf("        ");
	else
		(void)printf("%08lx", sym->n_value);

	/* print type information */
	if (IS_DEBUGGER_SYMBOL(sym->n_type))
		(void)printf(" - %02x %04x %5s ", sym->n_other,
		    sym->n_desc&0xffff, typestring(sym->n_type));
	else
		(void)printf(" %c ", typeletter(sym->n_type));

	/* print the symbol's name */
	(void)puts(sym->n_un.n_name);
}

/*
 * typestring()
 *	return the a description string for an STAB entry
 */
char *
typestring(type)
	register u_char type;
{
	switch(type) {
	case N_BCOMM:
		return("BCOMM");
	case N_ECOML:
		return("ECOML");
	case N_ECOMM:
		return("ECOMM");
	case N_ENTRY:
		return("ENTRY");
	case N_FNAME:
		return("FNAME");
	case N_FUN:
		return("FUN");
	case N_GSYM:
		return("GSYM");
	case N_LBRAC:
		return("LBRAC");
	case N_LCSYM:
		return("LCSYM");
	case N_LENG:
		return("LENG");
	case N_LSYM:
		return("LSYM");
	case N_PC:
		return("PC");
	case N_PSYM:
		return("PSYM");
	case N_RBRAC:
		return("RBRAC");
	case N_RSYM:
		return("RSYM");
	case N_SLINE:
		return("SLINE");
	case N_SO:
		return("SO");
	case N_SOL:
		return("SOL");
	case N_SSYM:
		return("SSYM");
	case N_STSYM:
		return("STSYM");
	}
	return("???");
}

/*
 * typeletter()
 *	return a description letter for the given basic type code of an
 *	symbol table entry.  The return value will be upper case for
 *	external, lower case for internal symbols.
 */
char
typeletter(type)
	u_char type;
{
	switch(SYMBOL_TYPE(type)) {
	case N_ABS:
		return(IS_EXTERNAL(type) ? 'A' : 'a');
	case N_BSS:
		return(IS_EXTERNAL(type) ? 'B' : 'b');
	case N_COMM:
		return(IS_EXTERNAL(type) ? 'C' : 'c');
	case N_DATA:
		return(IS_EXTERNAL(type) ? 'D' : 'd');
	case N_FN:
		/* NOTE: N_FN == N_WARNING,
		 * in this case, the N_EXT bit is to considered as
		 * part of the symbol's type itself.
		 */
		return(IS_EXTERNAL(type) ? 'F' : 'W');
	case N_TEXT:
		return(IS_EXTERNAL(type) ? 'T' : 't');
	case N_INDR:
		return(IS_EXTERNAL(type) ? 'I' : 'i');
	case N_SIZE:
		return(IS_EXTERNAL(type) ? 'S' : 's');
	case N_UNDF:
		return(IS_EXTERNAL(type) ? 'U' : 'u');
	}
	return('?');
}

fname(a0, b0)
	void *a0, *b0;
{
	struct nlist *a = a0, *b = b0;

	return(strcmp(a->n_un.n_name, b->n_un.n_name));
}

rname(a0, b0)
	void *a0, *b0;
{
	struct nlist *a = a0, *b = b0;

	return(strcmp(b->n_un.n_name, a->n_un.n_name));
}

value(a0, b0)
	void *a0, *b0;
{
	register struct nlist *a = a0, *b = b0;

	if (SYMBOL_TYPE(a->n_type) == N_UNDF)
		if (SYMBOL_TYPE(b->n_type) == N_UNDF)
			return(0);
		else
			return(-1);
	else if (SYMBOL_TYPE(b->n_type) == N_UNDF)
		return(1);
	if (rev) {
		if (a->n_value == b->n_value)
			return(rname(a0, b0));
		return(b->n_value > a->n_value ? 1 : -1);
	} else {
		if (a->n_value == b->n_value)
			return(fname(a0, b0));
		return(a->n_value > b->n_value ? 1 : -1);
	}
}

void *
emalloc(size)
	size_t size;
{
	char *p;

	/* NOSTRICT */
	if (p = malloc(size))
		return(p);
	err(1, NULL);
	exit(1);
}

void *
erealloc(p, size)
	void   *p;
	size_t size;
{
	/* NOSTRICT */
	if (p = realloc(p, size))
		return(p);
	err(1, NULL);
	exit(1);
}

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