* [PATCH 2/3] Avoid double exec() in execv_git_cmd()
2007-12-02 7:03 [PATCH 1/3] Prepare execv_git_cmd() for removal of builtins from the filesystem Junio C Hamano
@ 2007-12-02 7:03 ` Junio C Hamano
2007-12-02 7:03 ` [PATCH 3/3] git-shell: accept "git foo" form Junio C Hamano
2007-12-02 12:24 ` [PATCH 2/3] Avoid double exec() in execv_git_cmd() Johannes Schindelin
2007-12-02 8:48 ` [PATCH 1/3] Prepare execv_git_cmd() for removal of builtins from the filesystem Christian Couder
1 sibling, 2 replies; 5+ messages in thread
From: Junio C Hamano @ 2007-12-02 7:03 UTC (permalink / raw)
To: git
This avoids double exec() when execv_git_cmd() is used to spawn an
external git command.
For this, execv_git_cmd() needs to be able to tell what's built-in.
This is done by introducing a new function git_builtin_command() that
checks the list of built-in commands and returns a pointer to the
cmd_struct if found. The same function is used from the git potty.
This unfortunately pulls all built-in functions to libgit.a, so any
external command that happens to link with exec_cmd.o will need to pull
them in. I am not sure if that is worth it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
Makefile | 7 +-
exec_cmd.c | 208 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
exec_cmd.h | 8 ++
git.c | 155 +-------------------------------------------
4 files changed, 210 insertions(+), 168 deletions(-)
diff --git a/Makefile b/Makefile
index a7e44a3..6907954 100644
--- a/Makefile
+++ b/Makefile
@@ -893,7 +893,8 @@ git.o git.spec \
$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) $<
exec_cmd.o: exec_cmd.c GIT-CFLAGS
- $(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) '-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' $<
+ $(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) \
+ -DGIT_VERSION='"$(GIT_VERSION)"' '-DGIT_EXEC_PATH="$(gitexecdir_SQ)"' $<
builtin-init-db.o: builtin-init-db.c GIT-CFLAGS
$(QUIET_CC)$(CC) -o $*.o -c $(ALL_CFLAGS) -DDEFAULT_GIT_TEMPLATE_DIR='"$(template_dir_SQ)"' $<
@@ -923,8 +924,8 @@ $(LIB_OBJS) $(BUILTIN_OBJS): $(LIB_H)
$(patsubst git-%$X,%.o,$(PROGRAMS)): $(LIB_H) $(wildcard */*.h)
builtin-revert.o builtin-runstatus.o wt-status.o: wt-status.h
-$(LIB_FILE): $(LIB_OBJS)
- $(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(LIB_OBJS)
+$(LIB_FILE): $(LIB_OBJS) $(BUILTIN_OBJS)
+ $(QUIET_AR)$(RM) $@ && $(AR) rcs $@ $(LIB_OBJS) $(BUILTIN_OBJS)
XDIFF_OBJS=xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
xdiff/xmerge.o
diff --git a/exec_cmd.c b/exec_cmd.c
index 10b2908..db61540 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -1,3 +1,4 @@
+#include "builtin.h"
#include "cache.h"
#include "exec_cmd.h"
#include "quote.h"
@@ -63,27 +64,206 @@ void setup_path(const char *cmd_path)
strbuf_release(&new_path);
}
+#define RUN_SETUP (1<<0)
+#define USE_PAGER (1<<1)
+/*
+ * require working tree to be present -- anything uses this needs
+ * RUN_SETUP for reading from the configuration file.
+ */
+#define NEED_WORK_TREE (1<<2)
+
+const char git_version_string[] = GIT_VERSION;
+const char git_usage_string[] =
+ "git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate|--no-pager] [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE] [--help] COMMAND [ARGS]";
+
+int run_builtin_command(struct cmd_struct *p, int argc, const char **argv)
+{
+ int status;
+ struct stat st;
+ const char *prefix;
+
+ prefix = NULL;
+ if (p->option & RUN_SETUP)
+ prefix = setup_git_directory();
+ if (p->option & USE_PAGER)
+ setup_pager();
+ if (p->option & NEED_WORK_TREE)
+ setup_work_tree();
+
+ trace_argv_printf(argv, argc, "trace: built-in: git");
+
+ status = p->fn(argc, argv, prefix);
+ if (status)
+ return status & 0xff;
+
+ /* 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("write failure on standard output: %s", strerror(errno));
+ if (ferror(stdout))
+ die("unknown write failure on standard output");
+ if (fclose(stdout))
+ die("close failed on standard output: %s", strerror(errno));
+ return 0;
+}
+
+static struct cmd_struct builtin_command[] = {
+ { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
+ { "annotate", cmd_annotate, RUN_SETUP },
+ { "apply", cmd_apply },
+ { "archive", cmd_archive },
+ { "blame", cmd_blame, RUN_SETUP },
+ { "branch", cmd_branch, RUN_SETUP },
+ { "bundle", cmd_bundle },
+ { "cat-file", cmd_cat_file, RUN_SETUP },
+ { "check-attr", cmd_check_attr, RUN_SETUP | NEED_WORK_TREE },
+ { "check-ref-format", cmd_check_ref_format },
+ { "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 },
+ { "commit-tree", cmd_commit_tree, RUN_SETUP },
+ { "config", cmd_config },
+ { "count-objects", cmd_count_objects, RUN_SETUP },
+ { "describe", cmd_describe, RUN_SETUP },
+ { "diff", cmd_diff },
+ { "diff-files", cmd_diff_files },
+ { "diff-index", cmd_diff_index, RUN_SETUP },
+ { "diff-tree", cmd_diff_tree, RUN_SETUP },
+ { "fetch", cmd_fetch, RUN_SETUP },
+ { "fetch--tool", cmd_fetch__tool, 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 | USE_PAGER },
+ { "help", cmd_help },
+#ifndef NO_CURL
+ { "http-fetch", cmd_http_fetch, RUN_SETUP },
+#endif
+ { "init", cmd_init_db },
+ { "init-db", cmd_init_db },
+ { "log", cmd_log, RUN_SETUP | USE_PAGER },
+ { "ls-files", cmd_ls_files, RUN_SETUP },
+ { "ls-remote", cmd_ls_remote },
+ { "ls-tree", cmd_ls_tree, RUN_SETUP },
+ { "mailinfo", cmd_mailinfo },
+ { "mailsplit", cmd_mailsplit },
+ { "merge-base", cmd_merge_base, RUN_SETUP },
+ { "merge-file", cmd_merge_file },
+ { "merge-ours", cmd_merge_ours, RUN_SETUP },
+ { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
+ { "name-rev", cmd_name_rev, RUN_SETUP },
+ { "pack-objects", cmd_pack_objects, RUN_SETUP },
+ { "pack-refs", cmd_pack_refs, RUN_SETUP },
+ { "peek-remote", cmd_ls_remote },
+ { "pickaxe", cmd_blame, RUN_SETUP },
+ { "prune", cmd_prune, RUN_SETUP },
+ { "prune-packed", cmd_prune_packed, RUN_SETUP },
+ { "push", cmd_push, RUN_SETUP },
+ { "read-tree", cmd_read_tree, RUN_SETUP },
+ { "reflog", cmd_reflog, RUN_SETUP },
+ { "repo-config", cmd_config },
+ { "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 },
+ { "runstatus", cmd_runstatus, RUN_SETUP | NEED_WORK_TREE },
+ { "send-pack", cmd_send_pack, RUN_SETUP },
+ { "shortlog", cmd_shortlog, RUN_SETUP | USE_PAGER },
+ { "show", cmd_show, RUN_SETUP | USE_PAGER },
+ { "show-branch", cmd_show_branch, RUN_SETUP },
+ { "show-ref", cmd_show_ref, RUN_SETUP },
+ { "stripspace", cmd_stripspace },
+ { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
+ { "tag", cmd_tag, RUN_SETUP },
+ { "tar-tree", cmd_tar_tree },
+ { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
+ { "update-index", cmd_update_index, RUN_SETUP },
+ { "update-ref", cmd_update_ref, RUN_SETUP },
+ { "upload-archive", cmd_upload_archive },
+ { "verify-pack", cmd_verify_pack },
+ { "verify-tag", cmd_verify_tag, RUN_SETUP },
+ { "version", cmd_version },
+ { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
+ { "write-tree", cmd_write_tree, RUN_SETUP },
+};
+
+struct cmd_struct *git_builtin_command(const char *name)
+{
+ unsigned int hi, lo;
+ lo = 0;
+ hi = ARRAY_SIZE(builtin_command);
+ do {
+ unsigned mi = (lo + hi) / 2;
+ int cmp = strcmp(builtin_command[mi].cmd, name);
+ if (!cmp)
+ return &builtin_command[mi];
+ if (cmp > 0)
+ hi = mi;
+ else
+ lo = mi + 1;
+ } while (lo < hi);
+ return NULL;
+}
+
int execv_git_cmd(const char **argv)
{
- int argc;
- const char **nargv;
+ /*
+ * We exec "git foo" for builtin commands, but exec "git-foo"
+ * if "foo" is not a built-in, to avoid double exec overhead.
+ */
+ if (!git_builtin_command(argv[0])) {
+ struct strbuf cmd;
+ const char *save;
+
+ strbuf_init(&cmd, 0);
+ strbuf_addf(&cmd, "git-%s", argv[0]);
- for (argc = 0; argv[argc]; argc++)
- ; /* just counting */
- nargv = xmalloc(sizeof(*nargv) * (argc + 2));
+ save = argv[0];
+ argv[0] = cmd.buf;
+ trace_argv_printf(argv, -1, "trace: exec:");
- nargv[0] = "git";
- for (argc = 0; argv[argc]; argc++)
- nargv[argc + 1] = argv[argc];
- nargv[argc + 1] = NULL;
- trace_argv_printf(nargv, -1, "trace: exec:");
+ execvp(argv[0], (char **)argv);
- /* execvp() can only ever return if it fails */
- execvp("git", (char **)nargv);
+ trace_printf("trace: exec failed: %s\n", strerror(errno));
+ strbuf_release(&cmd);
+ argv[0] = save;
+ }
+ else {
+ int argc;
+ const char **nargv;
- trace_printf("trace: exec failed: %s\n", strerror(errno));
+ for (argc = 0; argv[argc]; argc++)
+ ; /* just counting */
+ nargv = xmalloc(sizeof(*nargv) * (argc + 2));
- free(nargv);
+ nargv[0] = "git";
+ for (argc = 0; argv[argc]; argc++)
+ nargv[argc + 1] = argv[argc];
+ nargv[argc + 1] = NULL;
+
+ trace_argv_printf(nargv, -1, "trace: exec:");
+
+ /* execvp() can only ever return if it fails */
+ execvp("git", (char **)nargv);
+
+ trace_printf("trace: exec failed: %s\n", strerror(errno));
+
+ free(nargv);
+ }
return -1;
}
diff --git a/exec_cmd.h b/exec_cmd.h
index a892355..184bc1d 100644
--- a/exec_cmd.h
+++ b/exec_cmd.h
@@ -7,5 +7,13 @@ extern void setup_path(const char *);
extern int execv_git_cmd(const char **argv); /* NULL terminated */
extern int execl_git_cmd(const char *cmd, ...);
+struct cmd_struct {
+ const char *cmd;
+ int (*fn)(int, const char **, const char *);
+ int option;
+};
+
+extern struct cmd_struct *git_builtin_command(const char *);
+extern int run_builtin_command(struct cmd_struct *p, int argc, const char **argv);
#endif /* GIT_EXEC_CMD_H */
diff --git a/git.c b/git.c
index d690426..9d86f5c 100644
--- a/git.c
+++ b/git.c
@@ -3,9 +3,6 @@
#include "cache.h"
#include "quote.h"
-const char git_usage_string[] =
- "git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate|--no-pager] [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE] [--help] COMMAND [ARGS]";
-
static int handle_options(const char*** argv, int* argc, int* envchanged)
{
int handled = 0;
@@ -222,151 +219,10 @@ static int handle_alias(int *argcp, const char ***argv)
return ret;
}
-const char git_version_string[] = GIT_VERSION;
-
-#define RUN_SETUP (1<<0)
-#define USE_PAGER (1<<1)
-/*
- * require working tree to be present -- anything uses this needs
- * RUN_SETUP for reading from the configuration file.
- */
-#define NEED_WORK_TREE (1<<2)
-
-struct cmd_struct {
- const char *cmd;
- int (*fn)(int, const char **, const char *);
- int option;
-};
-
-static int run_command(struct cmd_struct *p, int argc, const char **argv)
-{
- int status;
- struct stat st;
- const char *prefix;
-
- prefix = NULL;
- if (p->option & RUN_SETUP)
- prefix = setup_git_directory();
- if (p->option & USE_PAGER)
- setup_pager();
- if (p->option & NEED_WORK_TREE)
- setup_work_tree();
-
- trace_argv_printf(argv, argc, "trace: built-in: git");
-
- status = p->fn(argc, argv, prefix);
- if (status)
- return status & 0xff;
-
- /* 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("write failure on standard output: %s", strerror(errno));
- if (ferror(stdout))
- die("unknown write failure on standard output");
- if (fclose(stdout))
- die("close failed on standard output: %s", strerror(errno));
- return 0;
-}
-
static void handle_internal_command(int argc, const char **argv)
{
const char *cmd = argv[0];
- static struct cmd_struct commands[] = {
- { "add", cmd_add, RUN_SETUP | NEED_WORK_TREE },
- { "annotate", cmd_annotate, RUN_SETUP },
- { "apply", cmd_apply },
- { "archive", cmd_archive },
- { "blame", cmd_blame, RUN_SETUP },
- { "branch", cmd_branch, RUN_SETUP },
- { "bundle", cmd_bundle },
- { "cat-file", cmd_cat_file, RUN_SETUP },
- { "checkout-index", cmd_checkout_index,
- RUN_SETUP | NEED_WORK_TREE},
- { "check-ref-format", cmd_check_ref_format },
- { "check-attr", cmd_check_attr, 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 },
- { "commit-tree", cmd_commit_tree, RUN_SETUP },
- { "config", cmd_config },
- { "count-objects", cmd_count_objects, RUN_SETUP },
- { "describe", cmd_describe, RUN_SETUP },
- { "diff", cmd_diff },
- { "diff-files", cmd_diff_files },
- { "diff-index", cmd_diff_index, RUN_SETUP },
- { "diff-tree", cmd_diff_tree, RUN_SETUP },
- { "fetch", cmd_fetch, RUN_SETUP },
- { "fetch-pack", cmd_fetch_pack, RUN_SETUP },
- { "fetch--tool", cmd_fetch__tool, 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 | USE_PAGER },
- { "help", cmd_help },
-#ifndef NO_CURL
- { "http-fetch", cmd_http_fetch, RUN_SETUP },
-#endif
- { "init", cmd_init_db },
- { "init-db", cmd_init_db },
- { "log", cmd_log, RUN_SETUP | USE_PAGER },
- { "ls-files", cmd_ls_files, RUN_SETUP },
- { "ls-tree", cmd_ls_tree, RUN_SETUP },
- { "ls-remote", cmd_ls_remote },
- { "mailinfo", cmd_mailinfo },
- { "mailsplit", cmd_mailsplit },
- { "merge-base", cmd_merge_base, RUN_SETUP },
- { "merge-file", cmd_merge_file },
- { "merge-ours", cmd_merge_ours, RUN_SETUP },
- { "mv", cmd_mv, RUN_SETUP | NEED_WORK_TREE },
- { "name-rev", cmd_name_rev, RUN_SETUP },
- { "pack-objects", cmd_pack_objects, RUN_SETUP },
- { "peek-remote", cmd_ls_remote },
- { "pickaxe", cmd_blame, RUN_SETUP },
- { "prune", cmd_prune, RUN_SETUP },
- { "prune-packed", cmd_prune_packed, RUN_SETUP },
- { "push", cmd_push, RUN_SETUP },
- { "read-tree", cmd_read_tree, RUN_SETUP },
- { "reflog", cmd_reflog, RUN_SETUP },
- { "repo-config", cmd_config },
- { "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 },
- { "runstatus", cmd_runstatus, RUN_SETUP | NEED_WORK_TREE },
- { "send-pack", cmd_send_pack, RUN_SETUP },
- { "shortlog", cmd_shortlog, RUN_SETUP | USE_PAGER },
- { "show-branch", cmd_show_branch, RUN_SETUP },
- { "show", cmd_show, RUN_SETUP | USE_PAGER },
- { "stripspace", cmd_stripspace },
- { "symbolic-ref", cmd_symbolic_ref, RUN_SETUP },
- { "tag", cmd_tag, RUN_SETUP },
- { "tar-tree", cmd_tar_tree },
- { "unpack-objects", cmd_unpack_objects, RUN_SETUP },
- { "update-index", cmd_update_index, RUN_SETUP },
- { "update-ref", cmd_update_ref, RUN_SETUP },
- { "upload-archive", cmd_upload_archive },
- { "verify-tag", cmd_verify_tag, RUN_SETUP },
- { "version", cmd_version },
- { "whatchanged", cmd_whatchanged, RUN_SETUP | USE_PAGER },
- { "write-tree", cmd_write_tree, RUN_SETUP },
- { "verify-pack", cmd_verify_pack },
- { "show-ref", cmd_show_ref, RUN_SETUP },
- { "pack-refs", cmd_pack_refs, RUN_SETUP },
- };
- int i;
+ struct cmd_struct *builtin;
/* Turn "git cmd --help" into "git help cmd" */
if (argc > 1 && !strcmp(argv[1], "--help")) {
@@ -374,12 +230,9 @@ static void handle_internal_command(int argc, const char **argv)
argv[0] = cmd = "help";
}
- for (i = 0; i < ARRAY_SIZE(commands); i++) {
- struct cmd_struct *p = commands+i;
- if (strcmp(p->cmd, cmd))
- continue;
- exit(run_command(p, argc, argv));
- }
+ builtin = git_builtin_command(cmd);
+ if (builtin)
+ exit(run_builtin_command(builtin, argc, argv));
}
static void execv_dashed_external(const char **argv)
--
1.5.3.6.2090.g4ece0
^ permalink raw reply related [flat|nested] 5+ messages in thread