1 files changed, 165 insertions, 0 deletions

diff --git a/Documentation/perf_counter/exec_cmd.c b/Documentation/perf_counter/exec_cmd.c
new file mode 100644
index 000000000000..d39292263153
--- /dev/null
+++ b/Documentation/perf_counter/exec_cmd.c
@@ -0,0 +1,165 @@
+#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)
+{
+#ifdef RUNTIME_PREFIX
+        static const char *prefix;
+#else
+        static const char *prefix = PREFIX;
+#endif
+        struct strbuf d = STRBUF_INIT;
+
+        if (is_absolute_path(path))
+                return path;
+
+#ifdef RUNTIME_PREFIX
+        assert(argv0_path);
+        assert(is_absolute_path(argv0_path));
+
+        if (!prefix &&
+            !(prefix = strip_path_suffix(argv0_path, PERF_EXEC_PATH)) &&
+            !(prefix = strip_path_suffix(argv0_path, BINDIR)) &&
+            !(prefix = strip_path_suffix(argv0_path, "perf"))) {
+                prefix = PREFIX;
+                fprintf(stderr, "RUNTIME_PREFIX requested, "
+                                "but prefix computation failed.  "
+                                "Using static fallback '%s'.\n", prefix);
+        }
+#endif
+
+        strbuf_addf(&d, "%s/%s", prefix, path);
+        path = strbuf_detach(&d, NULL);
+        return path;
+}
+
+const char *perf_extract_argv0_path(const char *argv0)
+{
+        const char *slash;
+
+        if (!argv0 || !*argv0)
+                return NULL;
+        slash = argv0 + strlen(argv0);
+
+        while (argv0 <= slash && !is_dir_sep(*slash))
+                slash--;
+
+        if (slash >= argv0) {
+                argv0_path = strndup(argv0, slash - argv0);
+                return slash + 1;
+        }
+
+        return argv0;
+}
+
+void perf_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 perf programs. */
+const char *perf_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(PERF_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;
+
+        add_path(&new_path, perf_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_perf_cmd(const char **argv)
+{
+        int argc;
+        const char **nargv;
+
+        for (argc = 0; argv[argc]; argc++)
+                ; /* just counting */
+        nargv = malloc(sizeof(*nargv) * (argc + 2));
+
+        nargv[0] = "perf";
+        for (argc = 0; argv[argc]; argc++)
+                nargv[argc + 1] = argv[argc];
+        nargv[argc + 1] = NULL;
+        return nargv;
+}
+
+int execv_perf_cmd(const char **argv) {
+        const char **nargv = prepare_perf_cmd(argv);
+
+        /* execvp() can only ever return if it fails */
+        execvp("perf", (char **)nargv);
+
+        free(nargv);
+        return -1;
+}
+
+
+int execl_perf_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_perf_cmd(argv);
+}