From 1b593e1ea4d2af0f6444d9a7788d5d99abd6fde5 Mon Sep 17 00:00:00 2001 From: Vincent Ambo Date: Sat, 11 Jan 2020 23:36:56 +0000 Subject: Squashed 'third_party/git/' content from commit cb71568594 git-subtree-dir: third_party/git git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7 --- exec-cmd.c | 367 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 367 insertions(+) create mode 100644 exec-cmd.c (limited to 'exec-cmd.c') diff --git a/exec-cmd.c b/exec-cmd.c new file mode 100644 index 000000000000..7deeab30397c --- /dev/null +++ b/exec-cmd.c @@ -0,0 +1,367 @@ +#include "cache.h" +#include "exec-cmd.h" +#include "quote.h" +#include "argv-array.h" + +#if defined(RUNTIME_PREFIX) + +#if defined(HAVE_NS_GET_EXECUTABLE_PATH) +#include +#endif + +#if defined(HAVE_BSD_KERN_PROC_SYSCTL) +#include +#include +#include +#endif + +#endif /* RUNTIME_PREFIX */ + +#define MAX_ARGS 32 + +static const char *system_prefix(void); + +#ifdef RUNTIME_PREFIX + +/** + * When using a runtime prefix, Git dynamically resolves paths relative to its + * executable. + * + * The method for determining the path of the executable is highly + * platform-specific. + */ + +/** + * Path to the current Git executable. Resolved on startup by + * 'git_resolve_executable_dir'. + */ +static const char *executable_dirname; + +static const char *system_prefix(void) +{ + static const char *prefix; + + assert(executable_dirname); + assert(is_absolute_path(executable_dirname)); + + if (!prefix && + !(prefix = strip_path_suffix(executable_dirname, GIT_EXEC_PATH)) && + !(prefix = strip_path_suffix(executable_dirname, BINDIR)) && + !(prefix = strip_path_suffix(executable_dirname, "git"))) { + prefix = FALLBACK_RUNTIME_PREFIX; + trace_printf("RUNTIME_PREFIX requested, " + "but prefix computation failed. " + "Using static fallback '%s'.\n", prefix); + } + return prefix; +} + +/* + * Resolves the executable path from argv[0], only if it is absolute. + * + * Returns 0 on success, -1 on failure. + */ +static int git_get_exec_path_from_argv0(struct strbuf *buf, const char *argv0) +{ + const char *slash; + + if (!argv0 || !*argv0) + return -1; + + slash = find_last_dir_sep(argv0); + if (slash) { + trace_printf("trace: resolved executable path from argv0: %s\n", + argv0); + strbuf_add_absolute_path(buf, argv0); + return 0; + } + return -1; +} + +#ifdef PROCFS_EXECUTABLE_PATH +/* + * Resolves the executable path by examining a procfs symlink. + * + * Returns 0 on success, -1 on failure. + */ +static int git_get_exec_path_procfs(struct strbuf *buf) +{ + if (strbuf_realpath(buf, PROCFS_EXECUTABLE_PATH, 0)) { + trace_printf( + "trace: resolved executable path from procfs: %s\n", + buf->buf); + return 0; + } + return -1; +} +#endif /* PROCFS_EXECUTABLE_PATH */ + +#ifdef HAVE_BSD_KERN_PROC_SYSCTL +/* + * Resolves the executable path using KERN_PROC_PATHNAME BSD sysctl. + * + * Returns 0 on success, -1 on failure. + */ +static int git_get_exec_path_bsd_sysctl(struct strbuf *buf) +{ + int mib[4]; + char path[MAXPATHLEN]; + size_t cb = sizeof(path); + + mib[0] = CTL_KERN; + mib[1] = KERN_PROC; + mib[2] = KERN_PROC_PATHNAME; + mib[3] = -1; + if (!sysctl(mib, 4, path, &cb, NULL, 0)) { + trace_printf( + "trace: resolved executable path from sysctl: %s\n", + path); + strbuf_addstr(buf, path); + return 0; + } + return -1; +} +#endif /* HAVE_BSD_KERN_PROC_SYSCTL */ + +#ifdef HAVE_NS_GET_EXECUTABLE_PATH +/* + * Resolves the executable path by querying Darwin application stack. + * + * Returns 0 on success, -1 on failure. + */ +static int git_get_exec_path_darwin(struct strbuf *buf) +{ + char path[PATH_MAX]; + uint32_t size = sizeof(path); + if (!_NSGetExecutablePath(path, &size)) { + trace_printf( + "trace: resolved executable path from Darwin stack: %s\n", + path); + strbuf_addstr(buf, path); + return 0; + } + return -1; +} +#endif /* HAVE_NS_GET_EXECUTABLE_PATH */ + +#ifdef HAVE_WPGMPTR +/* + * Resolves the executable path by using the global variable _wpgmptr. + * + * Returns 0 on success, -1 on failure. + */ +static int git_get_exec_path_wpgmptr(struct strbuf *buf) +{ + int len = wcslen(_wpgmptr) * 3 + 1; + strbuf_grow(buf, len); + len = xwcstoutf(buf->buf, _wpgmptr, len); + if (len < 0) + return -1; + buf->len += len; + return 0; +} +#endif /* HAVE_WPGMPTR */ + +/* + * Resolves the absolute path of the current executable. + * + * Returns 0 on success, -1 on failure. + */ +static int git_get_exec_path(struct strbuf *buf, const char *argv0) +{ + /* + * Identifying the executable path is operating system specific. + * Selectively employ all available methods in order of preference, + * preferring highly-available authoritative methods over + * selectively-available or non-authoritative methods. + * + * All cases fall back on resolving against argv[0] if there isn't a + * better functional method. However, note that argv[0] can be + * used-supplied on many operating systems, and is not authoritative + * in those cases. + * + * Each of these functions returns 0 on success, so evaluation will stop + * after the first successful method. + */ + if ( +#ifdef HAVE_BSD_KERN_PROC_SYSCTL + git_get_exec_path_bsd_sysctl(buf) && +#endif /* HAVE_BSD_KERN_PROC_SYSCTL */ + +#ifdef HAVE_NS_GET_EXECUTABLE_PATH + git_get_exec_path_darwin(buf) && +#endif /* HAVE_NS_GET_EXECUTABLE_PATH */ + +#ifdef PROCFS_EXECUTABLE_PATH + git_get_exec_path_procfs(buf) && +#endif /* PROCFS_EXECUTABLE_PATH */ + +#ifdef HAVE_WPGMPTR + git_get_exec_path_wpgmptr(buf) && +#endif /* HAVE_WPGMPTR */ + + git_get_exec_path_from_argv0(buf, argv0)) { + return -1; + } + + if (strbuf_normalize_path(buf)) { + trace_printf("trace: could not normalize path: %s\n", buf->buf); + return -1; + } + + trace2_cmd_path(buf->buf); + + return 0; +} + +void git_resolve_executable_dir(const char *argv0) +{ + struct strbuf buf = STRBUF_INIT; + char *resolved; + const char *slash; + + if (git_get_exec_path(&buf, argv0)) { + trace_printf( + "trace: could not determine executable path from: %s\n", + argv0); + strbuf_release(&buf); + return; + } + + resolved = strbuf_detach(&buf, NULL); + slash = find_last_dir_sep(resolved); + if (slash) + resolved[slash - resolved] = '\0'; + + executable_dirname = resolved; + trace_printf("trace: resolved executable dir: %s\n", + executable_dirname); +} + +#else + +/* + * When not using a runtime prefix, Git uses a hard-coded path. + */ +static const char *system_prefix(void) +{ + return FALLBACK_RUNTIME_PREFIX; +} + +/* + * This is called during initialization, but No work needs to be done here when + * runtime prefix is not being used. + */ +void git_resolve_executable_dir(const char *argv0) +{ +} + +#endif /* RUNTIME_PREFIX */ + +char *system_path(const char *path) +{ + struct strbuf d = STRBUF_INIT; + + if (is_absolute_path(path)) + return xstrdup(path); + + strbuf_addf(&d, "%s/%s", system_prefix(), path); + return strbuf_detach(&d, NULL); +} + +static const char *exec_path_value; + +void git_set_exec_path(const char *exec_path) +{ + exec_path_value = 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) +{ + if (!exec_path_value) { + const char *env = getenv(EXEC_PATH_ENVIRONMENT); + if (env && *env) + exec_path_value = xstrdup(env); + else + exec_path_value = system_path(GIT_EXEC_PATH); + } + return exec_path_value; +} + +static void add_path(struct strbuf *out, const char *path) +{ + if (path && *path) { + strbuf_add_absolute_path(out, path); + strbuf_addch(out, PATH_SEP); + } +} + +void setup_path(void) +{ + const char *exec_path = git_exec_path(); + const char *old_path = getenv("PATH"); + struct strbuf new_path = STRBUF_INIT; + + git_set_exec_path(exec_path); + add_path(&new_path, exec_path); + + if (old_path) + strbuf_addstr(&new_path, old_path); + else + strbuf_addstr(&new_path, _PATH_DEFPATH); + + setenv("PATH", new_path.buf, 1); + + strbuf_release(&new_path); +} + +const char **prepare_git_cmd(struct argv_array *out, const char **argv) +{ + argv_array_push(out, "git"); + argv_array_pushv(out, argv); + return out->argv; +} + +int execv_git_cmd(const char **argv) +{ + struct argv_array nargv = ARGV_ARRAY_INIT; + + prepare_git_cmd(&nargv, argv); + trace_argv_printf(nargv.argv, "trace: exec:"); + + /* execvp() can only ever return if it fails */ + sane_execvp("git", (char **)nargv.argv); + + trace_printf("trace: exec failed: %s\n", strerror(errno)); + + argv_array_clear(&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); +} -- cgit 1.4.1