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git/git.c
Jeff King 3f2e2297b9 add an extra level of indirection to main() 
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>
2016-07-01 15:09:10 -07:00

718 lines
20 KiB
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#include "builtin.h"
#include "exec_cmd.h"
#include "help.h"
#include "run-command.h"
const char git_usage_string[] =
"git [--version] [--help] [-C <path>] [-c name=value]\n"
" [--exec-path[=<path>]] [--html-path] [--man-path] [--info-path]\n"
" [-p | --paginate | --no-pager] [--no-replace-objects] [--bare]\n"
" [--git-dir=<path>] [--work-tree=<path>] [--namespace=<name>]\n"
" <command> [<args>]";
const char git_more_info_string[] =
N_("'git help -a' and 'git help -g' list available subcommands and some\n"
"concept guides. See 'git help <command>' or 'git help <concept>'\n"
"to read about a specific subcommand or concept.");
static int use_pager = -1;
static char *orig_cwd;
static const char *env_names[] = {
GIT_DIR_ENVIRONMENT,
GIT_WORK_TREE_ENVIRONMENT,
GIT_IMPLICIT_WORK_TREE_ENVIRONMENT,
GIT_PREFIX_ENVIRONMENT
};
static char *orig_env[4];
static int save_restore_env_balance;
static void save_env_before_alias(void)
{
int i;
assert(save_restore_env_balance == 0);
save_restore_env_balance = 1;
orig_cwd = xgetcwd();
for (i = 0; i < ARRAY_SIZE(env_names); i++) {
orig_env[i] = getenv(env_names[i]);
if (orig_env[i])
orig_env[i] = xstrdup(orig_env[i]);
}
}
static void restore_env(int external_alias)
{
int i;
assert(save_restore_env_balance == 1);
save_restore_env_balance = 0;
if (!external_alias && orig_cwd && chdir(orig_cwd))
die_errno("could not move to %s", orig_cwd);
free(orig_cwd);
for (i = 0; i < ARRAY_SIZE(env_names); i++) {
if (external_alias &&
!strcmp(env_names[i], GIT_PREFIX_ENVIRONMENT))
continue;
if (orig_env[i]) {
setenv(env_names[i], orig_env[i], 1);
free(orig_env[i]);
} else {
unsetenv(env_names[i]);
}
}
}
static void commit_pager_choice(void) {
switch (use_pager) {
case 0:
setenv("GIT_PAGER", "cat", 1);
break;
case 1:
setup_pager();
break;
default:
break;
}
}
static int handle_options(const char ***argv, int *argc, int *envchanged)
{
const char **orig_argv = *argv;
while (*argc > 0) {
const char *cmd = (*argv)[0];
if (cmd[0] != '-')
break;
/*
* For legacy reasons, the "version" and "help"
* commands can be written with "--" prepended
* to make them look like flags.
*/
if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
break;
/*
* Check remaining flags.
*/
if (skip_prefix(cmd, "--exec-path", &cmd)) {
if (*cmd == '=')
git_set_argv_exec_path(cmd + 1);
else {
puts(git_exec_path());
exit(0);
}
} else if (!strcmp(cmd, "--html-path")) {
puts(system_path(GIT_HTML_PATH));
exit(0);
} else if (!strcmp(cmd, "--man-path")) {
puts(system_path(GIT_MAN_PATH));
exit(0);
} else if (!strcmp(cmd, "--info-path")) {
puts(system_path(GIT_INFO_PATH));
exit(0);
} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
use_pager = 1;
} else if (!strcmp(cmd, "--no-pager")) {
use_pager = 0;
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--no-replace-objects")) {
check_replace_refs = 0;
setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--git-dir")) {
if (*argc < 2) {
fprintf(stderr, "No directory given for --git-dir.\n" );
usage(git_usage_string);
}
setenv(GIT_DIR_ENVIRONMENT, (*argv)[1], 1);
if (envchanged)
*envchanged = 1;
(*argv)++;
(*argc)--;
} else if (skip_prefix(cmd, "--git-dir=", &cmd)) {
setenv(GIT_DIR_ENVIRONMENT, cmd, 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--namespace")) {
if (*argc < 2) {
fprintf(stderr, "No namespace given for --namespace.\n" );
usage(git_usage_string);
}
setenv(GIT_NAMESPACE_ENVIRONMENT, (*argv)[1], 1);
if (envchanged)
*envchanged = 1;
(*argv)++;
(*argc)--;
} else if (skip_prefix(cmd, "--namespace=", &cmd)) {
setenv(GIT_NAMESPACE_ENVIRONMENT, cmd, 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--work-tree")) {
if (*argc < 2) {
fprintf(stderr, "No directory given for --work-tree.\n" );
usage(git_usage_string);
}
setenv(GIT_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
if (envchanged)
*envchanged = 1;
(*argv)++;
(*argc)--;
} else if (skip_prefix(cmd, "--work-tree=", &cmd)) {
setenv(GIT_WORK_TREE_ENVIRONMENT, cmd, 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--bare")) {
char *cwd = xgetcwd();
is_bare_repository_cfg = 1;
setenv(GIT_DIR_ENVIRONMENT, cwd, 0);
free(cwd);
setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "-c")) {
if (*argc < 2) {
fprintf(stderr, "-c expects a configuration string\n" );
usage(git_usage_string);
}
git_config_push_parameter((*argv)[1]);
(*argv)++;
(*argc)--;
} else if (!strcmp(cmd, "--literal-pathspecs")) {
setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "1", 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--no-literal-pathspecs")) {
setenv(GIT_LITERAL_PATHSPECS_ENVIRONMENT, "0", 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--glob-pathspecs")) {
setenv(GIT_GLOB_PATHSPECS_ENVIRONMENT, "1", 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--noglob-pathspecs")) {
setenv(GIT_NOGLOB_PATHSPECS_ENVIRONMENT, "1", 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--icase-pathspecs")) {
setenv(GIT_ICASE_PATHSPECS_ENVIRONMENT, "1", 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "--shallow-file")) {
(*argv)++;
(*argc)--;
set_alternate_shallow_file((*argv)[0], 1);
if (envchanged)
*envchanged = 1;
} else if (!strcmp(cmd, "-C")) {
if (*argc < 2) {
fprintf(stderr, "No directory given for -C.\n" );
usage(git_usage_string);
}
if ((*argv)[1][0]) {
if (chdir((*argv)[1]))
die_errno("Cannot change to '%s'", (*argv)[1]);
if (envchanged)
*envchanged = 1;
}
(*argv)++;
(*argc)--;
} else {
fprintf(stderr, "Unknown option: %s\n", cmd);
usage(git_usage_string);
}
(*argv)++;
(*argc)--;
}
return (*argv) - orig_argv;
}
static int handle_alias(int *argcp, const char ***argv)
{
int envchanged = 0, ret = 0, saved_errno = errno;
int count, option_count;
const char **new_argv;
const char *alias_command;
char *alias_string;
int unused_nongit;
save_env_before_alias();
setup_git_directory_gently(&unused_nongit);
alias_command = (*argv)[0];
alias_string = alias_lookup(alias_command);
if (alias_string) {
if (alias_string[0] == '!') {
struct child_process child = CHILD_PROCESS_INIT;
commit_pager_choice();
restore_env(1);
child.use_shell = 1;
argv_array_push(&child.args, alias_string + 1);
argv_array_pushv(&child.args, (*argv) + 1);
ret = run_command(&child);
if (ret >= 0) /* normal exit */
exit(ret);
die_errno("While expanding alias '%s': '%s'",
alias_command, alias_string + 1);
}
count = split_cmdline(alias_string, &new_argv);
if (count < 0)
die("Bad alias.%s string: %s", alias_command,
split_cmdline_strerror(count));
option_count = handle_options(&new_argv, &count, &envchanged);
if (envchanged)
die("alias '%s' changes environment variables\n"
"You can use '!git' in the alias to do this.",
alias_command);
memmove(new_argv - option_count, new_argv,
count * sizeof(char *));
new_argv -= option_count;
if (count < 1)
die("empty alias for %s", alias_command);
if (!strcmp(alias_command, new_argv[0]))
die("recursive alias: %s", alias_command);
trace_argv_printf(new_argv,
"trace: alias expansion: %s =>",
alias_command);
REALLOC_ARRAY(new_argv, count + *argcp);
/* insert after command name */
memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
*argv = new_argv;
*argcp += count - 1;
ret = 1;
}
restore_env(0);
errno = saved_errno;
return ret;
}
#define RUN_SETUP (1<<0)
#define RUN_SETUP_GENTLY (1<<1)
#define USE_PAGER (1<<2)
/*
* require working tree to be present -- anything uses this needs
* RUN_SETUP for reading from the configuration file.
*/
#define NEED_WORK_TREE (1<<3)
struct cmd_struct {
const char *cmd;
int (*fn)(int, const char **, const char *);
int option;
};
static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
{
int status, help;
struct stat st;
const char *prefix;
prefix = NULL;
help = argc == 2 && !strcmp(argv[1], "-h");
if (!help) {
if (p->option & RUN_SETUP)
prefix = setup_git_directory();
else if (p->option & RUN_SETUP_GENTLY) {
int nongit_ok;
prefix = setup_git_directory_gently(&nongit_ok);
}
if (use_pager == -1 && p->option & (RUN_SETUP | RUN_SETUP_GENTLY))
use_pager = check_pager_config(p->cmd);
if (use_pager == -1 && p->option & USE_PAGER)
use_pager = 1;
if ((p->option & (RUN_SETUP | RUN_SETUP_GENTLY)) &&
startup_info->have_repository) /* get_git_dir() may set up repo, avoid that */
trace_repo_setup(prefix);
}
commit_pager_choice();
if (!help && p->option & NEED_WORK_TREE)
setup_work_tree();
trace_argv_printf(argv, "trace: built-in: git");
status = p->fn(argc, argv, prefix);
if (status)
return status;
/* Somebody closed stdout? */
if (fstat(fileno(stdout), &st))
return 0;
/* Ignore write errors for pipes and sockets.. */
if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
return 0;
/* Check for ENOSPC and EIO errors.. */
if (fflush(stdout))
die_errno("write failure on standard output");
if (ferror(stdout))
die("unknown write failure on standard output");
if (fclose(stdout))
die_errno("close failed on standard output");
return 0;
}
static struct cmd_struct commands[] = {
{ "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
{ "am", cmd_am, RUN_SETUP | NEED_WORK_TREE },
{ "annotate", cmd_annotate, RUN_SETUP },
{ "apply", cmd_apply, RUN_SETUP_GENTLY },
{ "archive", cmd_archive },
{ "bisect--helper", cmd_bisect__helper, RUN_SETUP },
{ "blame", cmd_blame, RUN_SETUP },
{ "branch", cmd_branch, RUN_SETUP },
{ "bundle", cmd_bundle, RUN_SETUP_GENTLY },
{ "cat-file", cmd_cat_file, RUN_SETUP },
{ "check-attr", cmd_check_attr, RUN_SETUP },
{ "check-ignore", cmd_check_ignore, RUN_SETUP | NEED_WORK_TREE },
{ "check-mailmap", cmd_check_mailmap, RUN_SETUP },
{ "check-ref-format", cmd_check_ref_format },
{ "checkout", cmd_checkout, RUN_SETUP | NEED_WORK_TREE },
{ "checkout-index", cmd_checkout_index,
RUN_SETUP | NEED_WORK_TREE},
{ "cherry", cmd_cherry, RUN_SETUP },
{ "cherry-pick", cmd_cherry_pick, RUN_SETUP | NEED_WORK_TREE },
{ "clean", cmd_clean, RUN_SETUP | NEED_WORK_TREE },
{ "clone", cmd_clone },
{ "column", cmd_column, RUN_SETUP_GENTLY },
{ "commit", cmd_commit, RUN_SETUP | NEED_WORK_TREE },
{ "commit-tree", cmd_commit_tree, RUN_SETUP },
{ "config", cmd_config, RUN_SETUP_GENTLY },
{ "count-objects", cmd_count_objects, RUN_SETUP },
{ "credential", cmd_credential, RUN_SETUP_GENTLY },
{ "describe", cmd_describe, RUN_SETUP },
{ "diff", cmd_diff },
{ "diff-files", cmd_diff_files, RUN_SETUP | NEED_WORK_TREE },
{ "diff-index", cmd_diff_index, RUN_SETUP },
{ "diff-tree", cmd_diff_tree, RUN_SETUP },
{ "fast-export", cmd_fast_export, RUN_SETUP },
{ "fetch", cmd_fetch, RUN_SETUP },
{ "fetch-pack", cmd_fetch_pack, RUN_SETUP },
{ "fmt-merge-msg", cmd_fmt_merge_msg, RUN_SETUP },
{ "for-each-ref", cmd_for_each_ref, RUN_SETUP },
{ "format-patch", cmd_format_patch, RUN_SETUP },
{ "fsck", cmd_fsck, RUN_SETUP },
{ "fsck-objects", cmd_fsck, RUN_SETUP },
{ "gc", cmd_gc, RUN_SETUP },
{ "get-tar-commit-id", cmd_get_tar_commit_id },
{ "grep", cmd_grep, RUN_SETUP_GENTLY },
{ "hash-object", cmd_hash_object },
{ "help", cmd_help },
{ "index-pack", cmd_index_pack, RUN_SETUP_GENTLY },
{ "init", cmd_init_db },
{ "init-db", cmd_init_db },
{ "interpret-trailers", cmd_interpret_trailers, RUN_SETUP_GENTLY },
{ "log", cmd_log, RUN_SETUP },
{ "ls-files", cmd_ls_files, RUN_SETUP },
{ "ls-remote", cmd_ls_remote, RUN_SETUP_GENTLY },
{ "ls-tree", cmd_ls_tree, RUN_SETUP },
{ "mailinfo", cmd_mailinfo },
{ "mailsplit", cmd_mailsplit },
{ "merge", cmd_merge, RUN_SETUP | NEED_WORK_TREE },
{ "merge-base", cmd_merge_base, RUN_SETUP },
{ "merge-file", cmd_merge_file, RUN_SETUP_GENTLY },
{ "merge-index", cmd_merge_index, RUN_SETUP },
{ "merge-ours", cmd_merge_ours, RUN_SETUP },
{ "merge-recursive", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
{ "merge-recursive-ours", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
{ "merge-recursive-theirs", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
{ "merge-subtree", cmd_merge_recursive, RUN_SETUP | NEED_WORK_TREE },
{ "merge-tree", cmd_merge_tree, RUN_SETUP },
{ "mktag", cmd_mktag, RUN_SETUP },
{ "mktree", cmd_mktree, RUN_SETUP },
{ "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
{ "name-rev", cmd_name_rev, RUN_SETUP },
{ "notes", cmd_notes, RUN_SETUP },
{ "pack-objects", cmd_pack_objects, RUN_SETUP },
{ "pack-redundant", cmd_pack_redundant, RUN_SETUP },
{ "pack-refs", cmd_pack_refs, RUN_SETUP },
{ "patch-id", cmd_patch_id },
{ "pickaxe", cmd_blame, RUN_SETUP },
{ "prune", cmd_prune, RUN_SETUP },
{ "prune-packed", cmd_prune_packed, RUN_SETUP },
{ "pull", cmd_pull, RUN_SETUP | NEED_WORK_TREE },
{ "push", cmd_push, RUN_SETUP },
{ "read-tree", cmd_read_tree, RUN_SETUP },
{ "receive-pack", cmd_receive_pack },
{ "reflog", cmd_reflog, RUN_SETUP },
{ "remote", cmd_remote, RUN_SETUP },
{ "remote-ext", cmd_remote_ext },
{ "remote-fd", cmd_remote_fd },
{ "repack", cmd_repack, RUN_SETUP },
{ "replace", cmd_replace, RUN_SETUP },
{ "rerere", cmd_rerere, RUN_SETUP },
{ "reset", cmd_reset, RUN_SETUP },
{ "rev-list", cmd_rev_list, RUN_SETUP },
{ "rev-parse", cmd_rev_parse },
{ "revert", cmd_revert, RUN_SETUP | NEED_WORK_TREE },
{ "rm", cmd_rm, RUN_SETUP },
{ "send-pack", cmd_send_pack, RUN_SETUP },
{ "shortlog", cmd_shortlog, RUN_SETUP_GENTLY | USE_PAGER },
{ "show", cmd_show, RUN_SETUP },
{ "show-branch", cmd_show_branch, RUN_SETUP },
{ "show-ref", cmd_show_ref, RUN_SETUP },
{ "stage", cmd_add, RUN_SETUP | NEED_WORK_TREE },
{ "status", cmd_status, RUN_SETUP | NEED_WORK_TREE },
{ "stripspace", cmd_stripspace },
{ "submodule--helper", cmd_submodule__helper, RUN_SETUP },
{ "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
{ "tag", cmd_tag, RUN_SETUP },
{ "unpack-file", cmd_unpack_file, RUN_SETUP },
{ "unpack-objects", cmd_unpack_objects, RUN_SETUP },
{ "update-index", cmd_update_index, RUN_SETUP },
{ "update-ref", cmd_update_ref, RUN_SETUP },
{ "update-server-info", cmd_update_server_info, RUN_SETUP },
{ "upload-archive", cmd_upload_archive },
{ "upload-archive--writer", cmd_upload_archive_writer },
{ "var", cmd_var, RUN_SETUP_GENTLY },
{ "verify-commit", cmd_verify_commit, RUN_SETUP },
{ "verify-pack", cmd_verify_pack },
{ "verify-tag", cmd_verify_tag, RUN_SETUP },
{ "version", cmd_version },
{ "whatchanged", cmd_whatchanged, RUN_SETUP },
{ "worktree", cmd_worktree, RUN_SETUP },
{ "write-tree", cmd_write_tree, RUN_SETUP },
};
static struct cmd_struct *get_builtin(const char *s)
{
int i;
for (i = 0; i < ARRAY_SIZE(commands); i++) {
struct cmd_struct *p = commands + i;
if (!strcmp(s, p->cmd))
return p;
}
return NULL;
}
int is_builtin(const char *s)
{
return !!get_builtin(s);
}
#ifdef STRIP_EXTENSION
static void strip_extension(const char **argv)
{
size_t len;
if (strip_suffix(argv[0], STRIP_EXTENSION, &len))
argv[0] = xmemdupz(argv[0], len);
}
#else
#define strip_extension(cmd)
#endif
static void handle_builtin(int argc, const char **argv)
{
const char *cmd;
struct cmd_struct *builtin;
strip_extension(argv);
cmd = argv[0];
/* Turn "git cmd --help" into "git help cmd" */
if (argc > 1 && !strcmp(argv[1], "--help")) {
argv[1] = argv[0];
argv[0] = cmd = "help";
}
builtin = get_builtin(cmd);
if (builtin)
exit(run_builtin(builtin, argc, argv));
}
static void execv_dashed_external(const char **argv)
{
struct strbuf cmd = STRBUF_INIT;
const char *tmp;
int status;
if (use_pager == -1)
use_pager = check_pager_config(argv[0]);
commit_pager_choice();
strbuf_addf(&cmd, "git-%s", argv[0]);
/*
* argv[0] must be the git command, but the argv array
* belongs to the caller, and may be reused in
* subsequent loop iterations. Save argv[0] and
* restore it on error.
*/
tmp = argv[0];
argv[0] = cmd.buf;
trace_argv_printf(argv, "trace: exec:");
/*
* if we fail because the command is not found, it is
* OK to return. Otherwise, we just pass along the status code.
*/
status = run_command_v_opt(argv, RUN_SILENT_EXEC_FAILURE | RUN_CLEAN_ON_EXIT);
if (status >= 0 || errno != ENOENT)
exit(status);
argv[0] = tmp;
strbuf_release(&cmd);
}
static int run_argv(int *argcp, const char ***argv)
{
int done_alias = 0;
while (1) {
/*
* If we tried alias and futzed with our environment,
* it no longer is safe to invoke builtins directly in
* general. We have to spawn them as dashed externals.
*
* NEEDSWORK: if we can figure out cases
* where it is safe to do, we can avoid spawning a new
* process.
*/
if (!done_alias)
handle_builtin(*argcp, *argv);
/* .. then try the external ones */
execv_dashed_external(*argv);
/* It could be an alias -- this works around the insanity
* of overriding "git log" with "git show" by having
* alias.log = show
*/
if (done_alias)
break;
if (!handle_alias(argcp, argv))
break;
done_alias = 1;
}
return done_alias;
}
/*
* Many parts of Git have subprograms communicate via pipe, expect the
* upstream of a pipe to die with SIGPIPE when the downstream of a
* pipe does not need to read all that is written. Some third-party
* programs that ignore or block SIGPIPE for their own reason forget
* to restore SIGPIPE handling to the default before spawning Git and
* break this carefully orchestrated machinery.
*
* Restore the way SIGPIPE is handled to default, which is what we
* expect.
*/
static void restore_sigpipe_to_default(void)
{
sigset_t unblock;
sigemptyset(&unblock);
sigaddset(&unblock, SIGPIPE);
sigprocmask(SIG_UNBLOCK, &unblock, NULL);
signal(SIGPIPE, SIG_DFL);
}
int cmd_main(int argc, const char **argv)
{
const char *cmd;
int done_help = 0;
cmd = git_extract_argv0_path(argv[0]);
if (!cmd)
cmd = "git-help";
/*
* Always open file descriptors 0/1/2 to avoid clobbering files
* in die(). It also avoids messing up when the pipes are dup'ed
* onto stdin/stdout/stderr in the child processes we spawn.
*/
sanitize_stdfds();
restore_sigpipe_to_default();
git_setup_gettext();
trace_command_performance(argv);
/*
* "git-xxxx" is the same as "git xxxx", but we obviously:
*
* - cannot take flags in between the "git" and the "xxxx".
* - cannot execute it externally (since it would just do
* the same thing over again)
*
* So we just directly call the builtin handler, and die if
* that one cannot handle it.
*/
if (skip_prefix(cmd, "git-", &cmd)) {
argv[0] = cmd;
handle_builtin(argc, argv);
die("cannot handle %s as a builtin", cmd);
}
/* Look for flags.. */
argv++;
argc--;
handle_options(&argv, &argc, NULL);
if (argc > 0) {
/* translate --help and --version into commands */
skip_prefix(argv[0], "--", &argv[0]);
} else {
/* The user didn't specify a command; give them help */
commit_pager_choice();
printf("usage: %s\n\n", git_usage_string);
list_common_cmds_help();
printf("\n%s\n", _(git_more_info_string));
exit(1);
}
cmd = argv[0];
/*
* We use PATH to find git commands, but we prepend some higher
* precedence paths: the "--exec-path" option, the GIT_EXEC_PATH
* environment, and the $(gitexecdir) from the Makefile at build
* time.
*/
setup_path();
while (1) {
int was_alias = run_argv(&argc, &argv);
if (errno != ENOENT)
break;
if (was_alias) {
fprintf(stderr, "Expansion of alias '%s' failed; "
"'%s' is not a git command\n",
cmd, argv[0]);
exit(1);
}
if (!done_help) {
cmd = argv[0] = help_unknown_cmd(cmd);
done_help = 1;
} else
break;
}
fprintf(stderr, "Failed to run command '%s': %s\n",
cmd, strerror(errno));
return 1;
}
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