mirror of
https://github.com/git/git
synced 2024-08-25 02:35:46 +00:00
3f2e2297b9
There are certain startup tasks that we expect every git process to do. In some cases this is just to improve the quality of the program (e.g., setting up gettext()). In others it is a requirement for using certain functions in libgit.a (e.g., system_path() expects that you have called git_extract_argv0_path()). Most commands are builtins and are covered by the git.c version of main(). However, there are still a few external commands that use their own main(). Each of these has to remember to include the correct startup sequence, and we are not always consistent. Rather than just fix the inconsistencies, let's make this harder to get wrong by providing a common main() that can run this standard startup. We basically have two options to do this: - the compat/mingw.h file already does something like this by adding a #define that replaces the definition of main with a wrapper that calls mingw_startup(). The upside is that the code in each program doesn't need to be changed at all; it's rewritten on the fly by the preprocessor. The downside is that it may make debugging of the startup sequence a bit more confusing, as the preprocessor is quietly inserting new code. - the builtin functions are all of the form cmd_foo(), and git.c's main() calls them. This is much more explicit, which may make things more obvious to somebody reading the code. It's also more flexible (because of course we have to figure out _which_ cmd_foo() to call). The downside is that each of the builtins must define cmd_foo(), instead of just main(). This patch chooses the latter option, preferring the more explicit approach, even though it is more invasive. We introduce a new file common-main.c, with the "real" main. It expects to call cmd_main() from whatever other objects it is linked against. We link common-main.o against anything that links against libgit.a, since we know that such programs will need to do this setup. Note that common-main.o can't actually go inside libgit.a, as the linker would not pick up its main() function automatically (it has no callers). The rest of the patch is just adjusting all of the various external programs (mostly in t/helper) to use cmd_main(). I've provided a global declaration for cmd_main(), which means that all of the programs also need to match its signature. In particular, many functions need to switch to "const char **" instead of "char **" for argv. This effect ripples out to a few other variables and functions, as well. This makes the patch even more invasive, but the end result is much better. We should be treating argv strings as const anyway, and now all programs conform to the same signature (which also matches the way builtins are defined). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
#include "cache.h"
|
|
#include "pack.h"
|
|
|
|
static const char show_index_usage[] =
|
|
"git show-index";
|
|
|
|
int cmd_main(int argc, const char **argv)
|
|
{
|
|
int i;
|
|
unsigned nr;
|
|
unsigned int version;
|
|
static unsigned int top_index[256];
|
|
|
|
git_setup_gettext();
|
|
|
|
if (argc != 1)
|
|
usage(show_index_usage);
|
|
if (fread(top_index, 2 * 4, 1, stdin) != 1)
|
|
die("unable to read header");
|
|
if (top_index[0] == htonl(PACK_IDX_SIGNATURE)) {
|
|
version = ntohl(top_index[1]);
|
|
if (version < 2 || version > 2)
|
|
die("unknown index version");
|
|
if (fread(top_index, 256 * 4, 1, stdin) != 1)
|
|
die("unable to read index");
|
|
} else {
|
|
version = 1;
|
|
if (fread(&top_index[2], 254 * 4, 1, stdin) != 1)
|
|
die("unable to read index");
|
|
}
|
|
nr = 0;
|
|
for (i = 0; i < 256; i++) {
|
|
unsigned n = ntohl(top_index[i]);
|
|
if (n < nr)
|
|
die("corrupt index file");
|
|
nr = n;
|
|
}
|
|
if (version == 1) {
|
|
for (i = 0; i < nr; i++) {
|
|
unsigned int offset, entry[6];
|
|
|
|
if (fread(entry, 4 + 20, 1, stdin) != 1)
|
|
die("unable to read entry %u/%u", i, nr);
|
|
offset = ntohl(entry[0]);
|
|
printf("%u %s\n", offset, sha1_to_hex((void *)(entry+1)));
|
|
}
|
|
} else {
|
|
unsigned off64_nr = 0;
|
|
struct {
|
|
unsigned char sha1[20];
|
|
uint32_t crc;
|
|
uint32_t off;
|
|
} *entries;
|
|
ALLOC_ARRAY(entries, nr);
|
|
for (i = 0; i < nr; i++)
|
|
if (fread(entries[i].sha1, 20, 1, stdin) != 1)
|
|
die("unable to read sha1 %u/%u", i, nr);
|
|
for (i = 0; i < nr; i++)
|
|
if (fread(&entries[i].crc, 4, 1, stdin) != 1)
|
|
die("unable to read crc %u/%u", i, nr);
|
|
for (i = 0; i < nr; i++)
|
|
if (fread(&entries[i].off, 4, 1, stdin) != 1)
|
|
die("unable to read 32b offset %u/%u", i, nr);
|
|
for (i = 0; i < nr; i++) {
|
|
uint64_t offset;
|
|
uint32_t off = ntohl(entries[i].off);
|
|
if (!(off & 0x80000000)) {
|
|
offset = off;
|
|
} else {
|
|
uint32_t off64[2];
|
|
if ((off & 0x7fffffff) != off64_nr)
|
|
die("inconsistent 64b offset index");
|
|
if (fread(off64, 8, 1, stdin) != 1)
|
|
die("unable to read 64b offset %u", off64_nr);
|
|
offset = (((uint64_t)ntohl(off64[0])) << 32) |
|
|
ntohl(off64[1]);
|
|
off64_nr++;
|
|
}
|
|
printf("%" PRIuMAX " %s (%08"PRIx32")\n",
|
|
(uintmax_t) offset,
|
|
sha1_to_hex(entries[i].sha1),
|
|
ntohl(entries[i].crc));
|
|
}
|
|
free(entries);
|
|
}
|
|
return 0;
|
|
}
|