git/exec_cmd.c
Johannes Sixt c90d565a46 Propagate --exec-path setting to external commands via GIT_EXEC_PATH
Let PATH0=$PATH that was set before the invocation.
Let /foo be a build directory.
Let /pfx be the installation prefix.
Let pfxexecpath=/pfx/libexec/git-core.

The following is going on when 'git --exec-path=/foo gc' is invoked:

1. git sets PATH=/foo:$PATH0 using the path from --exec-path

2. gc execs 'git repack' (note: no dash).

3. Since there is a git in /foo (it's a build directory), /foo/git is
   taken.

4. No explicit exec-path is set this time, hence, this secondary git sets
   PATH=$pfxexecpath:/foo:$PATH

5. Since 'repack' is not a built-in, execv_dashed_external execs
   'git-repack' (note: dash).

6. There is a $pfxexecpath/git-repack, and it is taken.

7. This git-repack runs 'git pack-objects' (note: no dash).

8. There is no git in $pfxexecpath, but there is one in /foo. Hence,
   /foo/git is run.

9. pack-objects is a builtin, hence, in effect /foo/git-pack-objects
   is run.

As you can see, the way in which we previously set the PATH allowed to
mix gits of different vintage.  By setting GIT_EXEC_PATH when --exec-path
was given on the command line, we reduce the confusion.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-03-21 21:45:14 -07:00

137 lines
2.6 KiB
C

#include "cache.h"
#include "exec_cmd.h"
#include "quote.h"
#define MAX_ARGS 32
extern char **environ;
static const char *argv_exec_path;
static const char *argv0_path;
const char *system_path(const char *path)
{
if (!is_absolute_path(path) && argv0_path) {
struct strbuf d = STRBUF_INIT;
strbuf_addf(&d, "%s/%s", argv0_path, path);
path = strbuf_detach(&d, NULL);
}
return path;
}
void git_set_argv0_path(const char *path)
{
argv0_path = path;
}
void git_set_argv_exec_path(const char *exec_path)
{
argv_exec_path = exec_path;
/*
* Propagate this setting to external programs.
*/
setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
}
/* Returns the highest-priority, location to look for git programs. */
const char *git_exec_path(void)
{
const char *env;
if (argv_exec_path)
return argv_exec_path;
env = getenv(EXEC_PATH_ENVIRONMENT);
if (env && *env) {
return env;
}
return system_path(GIT_EXEC_PATH);
}
static void add_path(struct strbuf *out, const char *path)
{
if (path && *path) {
if (is_absolute_path(path))
strbuf_addstr(out, path);
else
strbuf_addstr(out, make_nonrelative_path(path));
strbuf_addch(out, PATH_SEP);
}
}
void setup_path(void)
{
const char *old_path = getenv("PATH");
struct strbuf new_path;
strbuf_init(&new_path, 0);
add_path(&new_path, argv_exec_path);
add_path(&new_path, getenv(EXEC_PATH_ENVIRONMENT));
add_path(&new_path, system_path(GIT_EXEC_PATH));
add_path(&new_path, argv0_path);
if (old_path)
strbuf_addstr(&new_path, old_path);
else
strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
setenv("PATH", new_path.buf, 1);
strbuf_release(&new_path);
}
const char **prepare_git_cmd(const char **argv)
{
int argc;
const char **nargv;
for (argc = 0; argv[argc]; argc++)
; /* just counting */
nargv = xmalloc(sizeof(*nargv) * (argc + 2));
nargv[0] = "git";
for (argc = 0; argv[argc]; argc++)
nargv[argc + 1] = argv[argc];
nargv[argc + 1] = NULL;
return nargv;
}
int execv_git_cmd(const char **argv) {
const char **nargv = prepare_git_cmd(argv);
trace_argv_printf(nargv, "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;
}
int execl_git_cmd(const char *cmd,...)
{
int argc;
const char *argv[MAX_ARGS + 1];
const char *arg;
va_list param;
va_start(param, cmd);
argv[0] = cmd;
argc = 1;
while (argc < MAX_ARGS) {
arg = argv[argc++] = va_arg(param, char *);
if (!arg)
break;
}
va_end(param);
if (MAX_ARGS <= argc)
return error("too many args to run %s", cmd);
argv[argc] = NULL;
return execv_git_cmd(argv);
}