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nasm/misc/omfdump.c
H. Peter Anvin 6c105cea3b Improve misc/omfdump, add misc/Makefile, use -std=c23 if possible
- Add improvements to omfdump from Bernd Böckmann.

- Add misc/Makefile with option to install omfdump and auxiliary NASM
  data files.

- Use compiler.h and friends in the misc directory.

- Use -std=c23 if the C compiler supports it.

Cc: Bernd Boeckmann <bernd-github@boeckmann.io>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2025-09-03 10:05:21 -07:00

819 lines
20 KiB
C

/*
* omfdump.c
*
* Very simple program to dump the contents of an OMF (OBJ) file
*
* This assumes a littleendian, unaligned-load-capable host and a
* C compiler which handles basic C99.
*
* Copyright (c) 1996-2010, the NASM Authors
* Copyright (c) 2023, Bernd Boeckmann
*
* see LICENCE file for licensing terms
*/
#include "compiler.h"
#include "bytesex.h"
#include <ctype.h>
typedef struct {
uint16_t name_idx;
uint16_t class_idx;
uint16_t ovl_idx;
} segdef_t;
typedef struct {
uint16_t name_idx;
} grpdef_t;
const char *progname;
static const char *record_types[256] = {
[0x80] = "THEADR",
[0x82] = "LHEADR",
[0x88] = "COMENT",
[0x8a] = "MODEND16",
[0x8b] = "MODEND32",
[0x8c] = "EXTDEF",
[0x8e] = "TYPDEF",
[0x90] = "PUBDEF16",
[0x91] = "PUBDEF32",
[0x94] = "LINNUM16",
[0x95] = "LINNUM32",
[0x96] = "LNAMES",
[0x98] = "SEGDEF16",
[0x99] = "SEGDEF32",
[0x9a] = "GRPDEF",
[0x9c] = "FIXUPP16",
[0x9d] = "FIXUPP32",
[0xa0] = "LEDATA16",
[0xa1] = "LEDATA32",
[0xa2] = "LIDATA16",
[0xa3] = "LIDATA32",
[0xb0] = "COMDEF",
[0xb2] = "BAKPAT16",
[0xb3] = "BAKPAT32",
[0xb4] = "LEXTDEF",
[0xb6] = "LPUBDEF16",
[0xb7] = "LPUBDEF32",
[0xb8] = "LCOMDEF",
[0xbc] = "CEXTDEF",
[0xc2] = "COMDAT16",
[0xc3] = "COMDAT32",
[0xc4] = "LINSYM16",
[0xc5] = "LINSYM32",
[0xc6] = "ALIAS",
[0xc8] = "NBKPAT16",
[0xc9] = "NBKPAT32",
[0xca] = "LLNAMES",
[0xcc] = "VERNUM",
[0xce] = "VENDEXT",
[0xf0] = "LIBHDR",
[0xf1] = "LIBEND",
};
typedef void (*dump_func)(uint8_t, const uint8_t *, size_t);
/* Ordered collection type */
struct collection {
size_t n; /* Elements in collection (not including 0) */
size_t s; /* Elements allocated (not including 0) */
void const **p; /* Element pointers */
};
struct collection c_names, c_lsegs, c_groups, c_extsym;
static void *nulldie(void *ptr)
{
if (likely(ptr))
return ptr;
fprintf(stderr, "%s: memory allocation error\n", progname);
exit(1);
abort(); /* This should never happen */
}
static void *xmalloc(size_t size)
{
return nulldie(malloc(size));
}
static void *xrealloc(void *ptr, size_t size)
{
return nulldie(realloc(ptr, size));
}
/* Make sure there is enough space for at least one additional element */
static void *expand_buffer(void *buf, size_t *bufsizep, size_t datasize,
size_t elemsize)
{
size_t bufsize = *bufsizep;
if (likely(bufsize < datasize))
return buf;
if (bufsize < BUFSIZ)
bufsize = BUFSIZ;
else
bufsize <<= 1;
if (bufsize <= datasize)
bufsize = datasize+1;
buf = xrealloc(buf, bufsize * elemsize);
*bufsizep = bufsize;
return buf;
}
static void add_collection(struct collection *c, const void *p)
{
c->p = expand_buffer(c->p, &c->s, c->n, sizeof(const void *));
c->p[c->n++] = p;
}
static const void *get_collection(struct collection *c, size_t index,
const void *invalid)
{
if (index == 0 || index > c->n)
return invalid;
return c->p[index - 1];
}
static uint8_t *copy_name(size_t len, const uint8_t *data)
{
uint8_t *r = xmalloc(len + 1);
memcpy(r, data, len);
r[len] = '\0';
return r;
}
static void hexdump_data(unsigned int offset, const uint8_t *data,
size_t n, size_t field)
{
unsigned int i, j;
for (i = 0; i < n; i += 16) {
printf(" %04x: ", i + offset);
for (j = 0; j < 16; j++) {
char sep = (j == 7) ? '-' : ' ';
if (i + j < field)
printf("%02x%c", data[i + j], sep);
else if (i + j < n)
printf("xx%c", sep); /* Beyond end of... */
else
printf(" "); /* No separator */
}
printf(" : ");
for (j = 0; j < 16; j++) {
if (i + j < n)
putchar((i + j >= field) ? 'x' :
isprint(data[i + j]) ? data[i + j] : '.');
}
putchar('\n');
}
}
static void dump_unknown(uint8_t type, const uint8_t *data, size_t n)
{
(void)type;
hexdump_data(0, data, n, n);
}
static void print_dostime(const uint8_t *p)
{
uint16_t da = (p[3] << 8) + p[2];
uint16_t ti = (p[1] << 8) + p[0];
printf("%04u-%02u-%02u %02u:%02u:%02u",
(da >> 9) + 1980, (da >> 5) & 15, da & 31,
(ti >> 11), (ti >> 5) & 63, (ti << 1) & 63);
}
static void dump_coment_depfile(uint8_t type, const uint8_t *data, size_t n)
{
(void)type;
if (n > 4 && data[4] == n - 5) {
printf(" # ");
print_dostime(data);
printf(" %.*s\n", (int)(n - 5), data + 5);
}
hexdump_data(2, data, n, n);
}
static const dump_func dump_coment_class[256] = {
[0xe9] = dump_coment_depfile
};
static void dump_coment(uint8_t type, const uint8_t *data, size_t n)
{
uint8_t class;
static const char *coment_class[256] = {
[0x00] = "Translator",
[0x01] = "Copyright",
[0x81] = "Library specifier",
[0x9c] = "MS-DOS version",
[0x9d] = "Memory model",
[0x9e] = "DOSSEG",
[0x9f] = "Library search",
[0xa0] = "OMF extensions",
[0xa1] = "New OMF extension",
[0xa2] = "Link pass separator",
[0xa3] = "LIBMOD",
[0xa4] = "EXESTR",
[0xa6] = "INCERR",
[0xa7] = "NOPAD",
[0xa8] = "WKEXT",
[0xa9] = "LZEXT",
[0xda] = "Comment",
[0xdb] = "Compiler",
[0xdc] = "Date",
[0xdd] = "Timestamp",
[0xdf] = "User",
[0xe3] = "Type definition",
[0xe8] = "Filename",
[0xe9] = "Dependency file",
[0xff] = "Command line"
};
if (n < 2) {
hexdump_data(type, data, 2, n);
return;
}
type = data[0];
class = data[1];
printf(" [NP=%d NL=%d UD=%02X] %02X %s\n",
(type >> 7) & 1,
(type >> 6) & 1,
type & 0x3f,
class, coment_class[class] ? coment_class[class] : "???");
if (dump_coment_class[class])
dump_coment_class[class] (class, data + 2, n - 2);
else
hexdump_data(2, data + 2, n - 2, n - 2);
}
/* Parse an index field */
static uint16_t get_index(const uint8_t **pp)
{
uint8_t c;
c = *(*pp)++;
if (c & 0x80) {
return ((c & 0x7f) << 8) + *(*pp)++;
} else {
return c;
}
}
static uint16_t get_16(const uint8_t **pp)
{
uint16_t v = getu16(*pp);
(*pp) += 2;
return v;
}
static uint32_t get_32(const uint8_t **pp)
{
const uint32_t v = getu32(*pp);
(*pp) += 4;
return v;
}
/* Returns a name as a constant, persistent C string */
static const char *lname(int index)
{
return get_collection(&c_names, index, "");
}
static const char *segment_name(uint16_t segment_idx)
{
const segdef_t *seg;
seg = get_collection(&c_lsegs, segment_idx, NULL);
if (!seg)
return "";
return lname(seg->name_idx);
}
static const char *group_name(uint16_t group_idx)
{
const grpdef_t *grp;
grp = get_collection(&c_groups, group_idx, NULL);
if (!grp)
return "";
return lname(grp->name_idx);
}
static const char *external_name(uint16_t idx)
{
return get_collection(&c_extsym, idx, "");
}
/* LNAMES or LLNAMES */
static void dump_lnames(uint8_t type, const uint8_t *data, size_t n)
{
const uint8_t *p = data;
const uint8_t *end = data + n;
uint8_t *s;
(void)type;
while (p < end) {
size_t l = *p;
if (l > n) {
s = copy_name(n, p+1);
add_collection(&c_names, s);
printf(" # %4zu 0x%04zx: \"%.*s... <%zu missing bytes>\n",
c_names.n, c_names.n, (int)(n - 1), p + 1, l - n);
} else {
s = copy_name(l, p+1);
add_collection(&c_names, s);
printf(" [%04zx] '%s'\n", c_names.n, s);
}
hexdump_data(p - data, p, l + 1, n);
p += l + 1;
n -= l + 1;
}
}
/* SEGDEF16 or SEGDEF32 */
static void dump_segdef(uint8_t type, const uint8_t *data, size_t n)
{
bool big = type & 1;
const uint8_t *p = data;
const uint8_t *end = data + n;
uint8_t attr;
static const char *const alignment[8] =
{ "ABS", "BYTE", "WORD", "PARA", "PAGE", "DWORD", "LTL", "?ALIGN" };
static const char *const combine[8] =
{ "PRIVATE", "?COMMON", "PUBLIC", "?COMBINE", "?PUBLIC", "STACK",
"COMMON", "?PUBLIC" };
const char *s;
segdef_t *seg = xmalloc(sizeof(segdef_t));
if (p >= end)
return;
attr = *p++;
printf(" %s (A%u) %s (C%u) %s%s",
alignment[(attr >> 5) & 7], (attr >> 5) & 7,
combine[(attr >> 2) & 7], (attr >> 2) & 7,
(attr & 0x02) ? "MAXSIZE " : "", (attr & 0x01) ? "USE32" : "USE16");
if (((attr >> 5) & 7) == 0) {
/* Absolute segment */
if (p + 3 > end)
goto dump;
printf(" AT %04x:", get_16(&p));
printf("%02x", *p++);
}
if (big) {
if (p + 4 > end)
goto dump;
printf(" size %08x", get_32(&p));
} else {
if (p + 2 > end)
goto dump;
printf(" size %04x", get_16(&p));
}
puts("");
seg->name_idx = get_index(&p);
if (p > end)
goto dump;
s = lname(seg->name_idx);
printf(" name '%s'", s);
seg->class_idx = get_index(&p);
if (p > end)
goto dump;
s = lname(seg->class_idx);
if (*s) {
printf(", class '%s'", s);
}
seg->ovl_idx = get_index(&p);
if (p > end)
goto dump;
s = lname(seg->ovl_idx);
if (*s) { /* s points to empty string if no overlay is given */
printf(", ovl '%s'", s);
}
add_collection(&c_lsegs, seg);
dump:
putchar('\n');
hexdump_data(0, data, n, n);
}
static void dump_grpdef(uint8_t type, const uint8_t *data, size_t n)
{
const uint8_t *p = data;
const uint8_t *end = data + n;
const char *s;
uint16_t name_idx;
grpdef_t *grp;
(void)type;
grp = xmalloc(sizeof(grpdef_t));
name_idx = get_index(&p);
grp->name_idx = name_idx;
if (p > end)
goto dump;
add_collection(&c_groups, grp);
s = lname(name_idx);
printf(" name '%s'\n", s);
while (p < end) {
if (*p == 0xff) { /* segment */
p++;
printf(" segment '%s'\n", segment_name(get_index(&p)));
} else if (*p == 0xfe) {
p++;
name_idx = get_index(&p);
s = lname(name_idx);
printf(" external '%s'\n", s);
} else
goto dump;
}
dump:
hexdump_data(0, data, n, n);
}
static const char *const method_base[16] = {
"SEGDEF", "GRPDEF", "EXTDEF", "frame#",
"SEGDEF", "GRPDEF", "EXTDEF", "unsupported",
"SEGDEF", "GRPDEF", "EXTDEF", "frame#",
"prev. LEDATA SEG index", "TARGET index", "invalid", "unsupported"
};
static const char *location_descr[16] = {
"low-order byte", "16-bit offset", "16-bit segment", "32-bit far ptr",
"hi-order byte", "16-bit ldr-resolved offset", "reserved", "reserved",
"unknown", "32-bit offset", "unknown", "48-bit ptr", "unknown",
"32-bit ldr-resolved offset", "unknown", "unknown"
};
/* helper routine used in fixup and modend dumps */
static void dump_fixdat(bool big, const uint8_t **data)
{
const uint8_t *p = *data;
uint8_t fix;
uint16_t idx;
fix = *p++;
/* frame decoding */
printf("\n frame %s%d%s",
(fix & 0x80) ? "thread " : "method F",
((fix & 0x70) >> 4), ((fix & 0xc0) == 0xc0) ? "?" : "");
if ((fix & 0x80) == 0)
printf(" (%s)", method_base[((fix >> 4) & 7) + 8]);
if ((fix & 0xc0) == 0) {
idx = get_index(&p);
printf(" index %04x", idx);
if ((fix >> 4) == 0) {
printf(" '%s'", segment_name(idx));
} else if ((fix >> 4) == 1) {
printf(" '%s'", group_name(idx));
} else if ((fix >> 4) == 2) {
printf(" '%s'", external_name(idx));
}
}
/* target decoding */
printf("\n target %s%d",
(fix & 0x08) ? "thread " : "method T", fix & 7);
if ((fix & 0x08) == 0)
printf(" (%s)", method_base[(fix & 7)]);
if ((fix & 0x08) == 0) {
idx = get_index(&p);
printf(" index %04x", idx);
if ((fix & 3) == 0) {
printf(" '%s'", segment_name(idx));
} else if ((fix & 3) == 1) {
printf(" '%s'", group_name(idx));
} else if ((fix & 3) == 2) {
printf(" '%s'", external_name(idx));
}
}
if ((fix & 0x04) == 0) {
if (big) {
printf(" disp %08x", get_32(&p));
} else {
printf(" disp %04x", get_16(&p));
}
}
putchar('\n');
*data = p;
}
/* FIXUPP16 or FIXUPP32 */
static void dump_fixupp(uint8_t type, const uint8_t *data, size_t n)
{
bool big = type & 1;
const uint8_t *p = data;
const uint8_t *end = data + n;
while (p < end) {
const uint8_t *start = p;
uint8_t op = *p++;
if (!(op & 0x80)) {
/* THREAD record */
bool frame = !!(op & 0x40);
printf(" THREAD %-7s%d%s method %c%d (%s)",
frame ? "frame" : "target", op & 3,
(op & 0x20) ? " +flag5?" : "",
(op & 0x40) ? 'F' : 'T',
((op & 0x1c) >> 2),
method_base[((op & 0x40) >> 3) | ((op & 0x1c) >> 2)]);
if ((op & 0x50) != 0x50) {
printf(" index %04x", get_index(&p));
}
putchar('\n');
} else {
/* FIXUP subrecord */
printf(" FIXUP %s-relative, type %d (%s)\n"
" record offset %04x",
(op & 0x40) ? "segment" : "self",
(op & 0x3c) >> 2,
location_descr[(op & 0x3c) >> 2], ((op & 3) << 8) + *p++);
dump_fixdat(big, &p);
}
hexdump_data(start - data, start, p - start, n - (start - data));
}
}
static void dump_ledata(uint8_t type, const uint8_t *data, size_t n)
{
bool big = type & 1;
const uint8_t *p = data;
const segdef_t *seg = get_collection(&c_lsegs, get_index(&p), NULL);
const char *seg_name = "(null)";
size_t data_len;
if (seg != NULL)
seg_name = lname(seg->name_idx);
printf(" segment '%s', ", seg_name);
if (big) {
printf("offset %08x\n", get_32(&p));
} else {
printf("offset %04x\n", get_16(&p));
}
data_len = n - (p - data);
hexdump_data(0, p, data_len, data_len);
}
static void dump_pubdef(uint8_t type, const uint8_t *data, size_t n)
{
static int pub_names_count;
bool big = type & 1;
const uint8_t *p = data;
const uint8_t *end = data + n;
uint16_t grp_idx;
uint16_t seg_idx;
uint16_t type_idx;
int name_len;
grp_idx = get_index(&p);
if (p > end)
goto dump;
seg_idx = get_index(&p);
if (p > end)
goto dump;
if (grp_idx == 0 && seg_idx == 0) {
printf(" frame %04x", get_16(&p));
} else {
printf(" ");
if (seg_idx) {
printf(" segment '%s'", segment_name(seg_idx));
}
if (grp_idx) {
printf(" group '%s'", group_name(grp_idx));
}
}
puts("");
while (p < end) {
pub_names_count++;
name_len = *p++;
printf(" [%04x] public name '%.*s' ", pub_names_count, name_len, p);
p += name_len;
if (big) {
printf("offset %08x", get_32(&p));
} else {
printf("offset %04x", get_16(&p));
}
type_idx = get_index(&p);
if (type_idx) {
printf(", type %d", type_idx);
}
puts("");
}
dump:
hexdump_data(0, data, n, n);
}
static void dump_extdef(uint8_t type, const uint8_t *data, size_t n)
{
static int ext_names_count;
const uint8_t *p = data;
const uint8_t *end = data + n;
uint16_t type_idx;
int name_len;
uint8_t *name;
(void)type;
while (p < end) {
ext_names_count++;
name_len = *p++;
name = copy_name(name_len, p);
add_collection(&c_extsym, name);
p += name_len;
printf(" [%04x] external name '%s'", ext_names_count, name);
type_idx = get_index(&p);
if (type_idx) {
printf(", type %d", type_idx);
}
puts("");
}
hexdump_data(0, data, n, n);
}
static void dump_modend(uint8_t type, const uint8_t *data, size_t n)
{
const uint8_t *p = data;
if (*p & 0x80)
printf(" main module\n");
if (*p & 0x40) {
printf(" start address:");
p++;
dump_fixdat(type & 1, &p);
}
hexdump_data(0, data, n, n);
}
static const dump_func dump_type[256] = {
[0x88] = dump_coment,
[0x8a] = dump_modend,
[0x8c] = dump_extdef,
[0x90] = dump_pubdef,
[0x91] = dump_pubdef,
[0x96] = dump_lnames,
[0x98] = dump_segdef,
[0x99] = dump_segdef,
[0x9a] = dump_grpdef,
[0x9c] = dump_fixupp,
[0x9d] = dump_fixupp,
[0xa0] = dump_ledata,
[0xa1] = dump_ledata,
[0xca] = dump_lnames,
};
static uint8_t *read_file(FILE *f, size_t *sz)
{
uint8_t *buf = NULL;
size_t bufsize = 0;
size_t bytes;
size_t size = 0;
if (fseek(f, 0, SEEK_END)) {
/* Try to get the size of the file to preallocate buffer */
bufsize = ftell(f);
if (bufsize)
buf = xmalloc(bufsize);
}
rewind(f);
do {
buf = expand_buffer(buf, &bufsize, size, 1);
bytes = fread(buf + size, 1, bufsize - size, f);
if (ferror(f)) {
free(buf);
*sz = 0;
return NULL;
}
size += bytes;
} while (bytes && !feof(f));
*sz = size;
if (size != bufsize)
buf = xrealloc(buf, size);
return buf;
}
static int dump_omf(FILE *f)
{
size_t len, n;
uint8_t type;
const uint8_t *p, *data;
data = read_file(f, &len);
if (!data)
return -1;
p = data;
while (len >= 3 && *p != 0x1a) {
uint8_t csum;
int i;
type = p[0];
n = *(uint16_t *) (p + 1);
printf("%02x %-10s %4zd bytes",
type, record_types[type] ? record_types[type] : "???", n);
if (len < n + 3) {
printf("\n (truncated, only %zd bytes left)\n", len - 3);
break; /* Truncated */
}
p += 3; /* Header doesn't count in the length */
n--; /* Remove checksum byte */
csum = 0;
for (i = -3; i < (int)n; i++)
csum -= p[i];
printf(", checksum %02X", p[i]);
if (csum == p[i])
printf(" (valid)\n");
else
printf(" (actual = %02X)\n", csum);
if (dump_type[type])
dump_type[type] (type, p, n);
else
dump_unknown(type, p, n);
p += n + 1;
len -= (n + 4);
}
free((void *)data);
return 0;
}
int main(int argc, char *argv[])
{
FILE *f;
int i;
progname = argv[0];
if (argc < 2) {
fputs("omfdump - dump contents of object module files to stdout\n"
"Usage: omfdump file...\n", stdout);
return 0;
}
for (i = 1; i < argc; i++) {
f = fopen(argv[i], "rb");
if (!f || dump_omf(f)) {
perror(argv[i]);
return 1;
}
fclose(f);
}
return 0;
}