perf_counter tools: add in basic glue from Git

First very raw version at having a central 'perf' command and
a list of subcommands:

  perf top
  perf stat
  perf record
  perf report
  ...

This is done by picking up Git's collection of utility functions,
and hacking them to build fine in this new environment.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 395 insertions, 0 deletions

diff --git a/Documentation/perf_counter/run-command.c b/Documentation/perf_counter/run-command.c
new file mode 100644
index 000000000000..b2f5e854f40a
--- /dev/null
+++ b/Documentation/perf_counter/run-command.c
@@ -0,0 +1,395 @@
+#include "cache.h"
+#include "run-command.h"
+#include "exec_cmd.h"
+
+static inline void close_pair(int fd[2])
+{
+        close(fd[0]);
+        close(fd[1]);
+}
+
+static inline void dup_devnull(int to)
+{
+        int fd = open("/dev/null", O_RDWR);
+        dup2(fd, to);
+        close(fd);
+}
+
+int start_command(struct child_process *cmd)
+{
+        int need_in, need_out, need_err;
+        int fdin[2], fdout[2], fderr[2];
+
+        /*
+         * In case of errors we must keep the promise to close FDs
+         * that have been passed in via ->in and ->out.
+         */
+
+        need_in = !cmd->no_stdin && cmd->in < 0;
+        if (need_in) {
+                if (pipe(fdin) < 0) {
+                        if (cmd->out > 0)
+                                close(cmd->out);
+                        return -ERR_RUN_COMMAND_PIPE;
+                }
+                cmd->in = fdin[1];
+        }
+
+        need_out = !cmd->no_stdout
+                && !cmd->stdout_to_stderr
+                && cmd->out < 0;
+        if (need_out) {
+                if (pipe(fdout) < 0) {
+                        if (need_in)
+                                close_pair(fdin);
+                        else if (cmd->in)
+                                close(cmd->in);
+                        return -ERR_RUN_COMMAND_PIPE;
+                }
+                cmd->out = fdout[0];
+        }
+
+        need_err = !cmd->no_stderr && cmd->err < 0;
+        if (need_err) {
+                if (pipe(fderr) < 0) {
+                        if (need_in)
+                                close_pair(fdin);
+                        else if (cmd->in)
+                                close(cmd->in);
+                        if (need_out)
+                                close_pair(fdout);
+                        else if (cmd->out)
+                                close(cmd->out);
+                        return -ERR_RUN_COMMAND_PIPE;
+                }
+                cmd->err = fderr[0];
+        }
+
+#ifndef __MINGW32__
+        fflush(NULL);
+        cmd->pid = fork();
+        if (!cmd->pid) {
+                if (cmd->no_stdin)
+                        dup_devnull(0);
+                else if (need_in) {
+                        dup2(fdin[0], 0);
+                        close_pair(fdin);
+                } else if (cmd->in) {
+                        dup2(cmd->in, 0);
+                        close(cmd->in);
+                }
+
+                if (cmd->no_stderr)
+                        dup_devnull(2);
+                else if (need_err) {
+                        dup2(fderr[1], 2);
+                        close_pair(fderr);
+                }
+
+                if (cmd->no_stdout)
+                        dup_devnull(1);
+                else if (cmd->stdout_to_stderr)
+                        dup2(2, 1);
+                else if (need_out) {
+                        dup2(fdout[1], 1);
+                        close_pair(fdout);
+                } else if (cmd->out > 1) {
+                        dup2(cmd->out, 1);
+                        close(cmd->out);
+                }
+
+                if (cmd->dir && chdir(cmd->dir))
+                        die("exec %s: cd to %s failed (%s)", cmd->argv[0],
+                            cmd->dir, strerror(errno));
+                if (cmd->env) {
+                        for (; *cmd->env; cmd->env++) {
+                                if (strchr(*cmd->env, '='))
+                                        putenv((char*)*cmd->env);
+                                else
+                                        unsetenv(*cmd->env);
+                        }
+                }
+                if (cmd->preexec_cb)
+                        cmd->preexec_cb();
+                if (cmd->perf_cmd) {
+                        execv_perf_cmd(cmd->argv);
+                } else {
+                        execvp(cmd->argv[0], (char *const*) cmd->argv);
+                }
+                exit(127);
+        }
+#else
+        int s0 = -1, s1 = -1, s2 = -1;  /* backups of stdin, stdout, stderr */
+        const char **sargv = cmd->argv;
+        char **env = environ;
+
+        if (cmd->no_stdin) {
+                s0 = dup(0);
+                dup_devnull(0);
+        } else if (need_in) {
+                s0 = dup(0);
+                dup2(fdin[0], 0);
+        } else if (cmd->in) {
+                s0 = dup(0);
+                dup2(cmd->in, 0);
+        }
+
+        if (cmd->no_stderr) {
+                s2 = dup(2);
+                dup_devnull(2);
+        } else if (need_err) {
+                s2 = dup(2);
+                dup2(fderr[1], 2);
+        }
+
+        if (cmd->no_stdout) {
+                s1 = dup(1);
+                dup_devnull(1);
+        } else if (cmd->stdout_to_stderr) {
+                s1 = dup(1);
+                dup2(2, 1);
+        } else if (need_out) {
+                s1 = dup(1);
+                dup2(fdout[1], 1);
+        } else if (cmd->out > 1) {
+                s1 = dup(1);
+                dup2(cmd->out, 1);
+        }
+
+        if (cmd->dir)
+                die("chdir in start_command() not implemented");
+        if (cmd->env) {
+                env = copy_environ();
+                for (; *cmd->env; cmd->env++)
+                        env = env_setenv(env, *cmd->env);
+        }
+
+        if (cmd->perf_cmd) {
+                cmd->argv = prepare_perf_cmd(cmd->argv);
+        }
+
+        cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env);
+
+        if (cmd->env)
+                free_environ(env);
+        if (cmd->perf_cmd)
+                free(cmd->argv);
+
+        cmd->argv = sargv;
+        if (s0 >= 0)
+                dup2(s0, 0), close(s0);
+        if (s1 >= 0)
+                dup2(s1, 1), close(s1);
+        if (s2 >= 0)
+                dup2(s2, 2), close(s2);
+#endif
+
+        if (cmd->pid < 0) {
+                int err = errno;
+                if (need_in)
+                        close_pair(fdin);
+                else if (cmd->in)
+                        close(cmd->in);
+                if (need_out)
+                        close_pair(fdout);
+                else if (cmd->out)
+                        close(cmd->out);
+                if (need_err)
+                        close_pair(fderr);
+                return err == ENOENT ?
+                        -ERR_RUN_COMMAND_EXEC :
+                        -ERR_RUN_COMMAND_FORK;
+        }
+
+        if (need_in)
+                close(fdin[0]);
+        else if (cmd->in)
+                close(cmd->in);
+
+        if (need_out)
+                close(fdout[1]);
+        else if (cmd->out)
+                close(cmd->out);
+
+        if (need_err)
+                close(fderr[1]);
+
+        return 0;
+}
+
+static int wait_or_whine(pid_t pid)
+{
+        for (;;) {
+                int status, code;
+                pid_t waiting = waitpid(pid, &status, 0);
+
+                if (waiting < 0) {
+                        if (errno == EINTR)
+                                continue;
+                        error("waitpid failed (%s)", strerror(errno));
+                        return -ERR_RUN_COMMAND_WAITPID;
+                }
+                if (waiting != pid)
+                        return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
+                if (WIFSIGNALED(status))
+                        return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
+
+                if (!WIFEXITED(status))
+                        return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
+                code = WEXITSTATUS(status);
+                switch (code) {
+                case 127:
+                        return -ERR_RUN_COMMAND_EXEC;
+                case 0:
+                        return 0;
+                default:
+                        return -code;
+                }
+        }
+}
+
+int finish_command(struct child_process *cmd)
+{
+        return wait_or_whine(cmd->pid);
+}
+
+int run_command(struct child_process *cmd)
+{
+        int code = start_command(cmd);
+        if (code)
+                return code;
+        return finish_command(cmd);
+}
+
+static void prepare_run_command_v_opt(struct child_process *cmd,
+                                      const char **argv,
+                                      int opt)
+{
+        memset(cmd, 0, sizeof(*cmd));
+        cmd->argv = argv;
+        cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
+        cmd->perf_cmd = opt & RUN_PERF_CMD ? 1 : 0;
+        cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
+}
+
+int run_command_v_opt(const char **argv, int opt)
+{
+        struct child_process cmd;
+        prepare_run_command_v_opt(&cmd, argv, opt);
+        return run_command(&cmd);
+}
+
+int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
+{
+        struct child_process cmd;
+        prepare_run_command_v_opt(&cmd, argv, opt);
+        cmd.dir = dir;
+        cmd.env = env;
+        return run_command(&cmd);
+}
+
+#ifdef __MINGW32__
+static __stdcall unsigned run_thread(void *data)
+{
+        struct async *async = data;
+        return async->proc(async->fd_for_proc, async->data);
+}
+#endif
+
+int start_async(struct async *async)
+{
+        int pipe_out[2];
+
+        if (pipe(pipe_out) < 0)
+                return error("cannot create pipe: %s", strerror(errno));
+        async->out = pipe_out[0];
+
+#ifndef __MINGW32__
+        /* Flush stdio before fork() to avoid cloning buffers */
+        fflush(NULL);
+
+        async->pid = fork();
+        if (async->pid < 0) {
+                error("fork (async) failed: %s", strerror(errno));
+                close_pair(pipe_out);
+                return -1;
+        }
+        if (!async->pid) {
+                close(pipe_out[0]);
+                exit(!!async->proc(pipe_out[1], async->data));
+        }
+        close(pipe_out[1]);
+#else
+        async->fd_for_proc = pipe_out[1];
+        async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
+        if (!async->tid) {
+                error("cannot create thread: %s", strerror(errno));
+                close_pair(pipe_out);
+                return -1;
+        }
+#endif
+        return 0;
+}
+
+int finish_async(struct async *async)
+{
+#ifndef __MINGW32__
+        int ret = 0;
+
+        if (wait_or_whine(async->pid))
+                ret = error("waitpid (async) failed");
+#else
+        DWORD ret = 0;
+        if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
+                ret = error("waiting for thread failed: %lu", GetLastError());
+        else if (!GetExitCodeThread(async->tid, &ret))
+                ret = error("cannot get thread exit code: %lu", GetLastError());
+        CloseHandle(async->tid);
+#endif
+        return ret;
+}
+
+int run_hook(const char *index_file, const char *name, ...)
+{
+        struct child_process hook;
+        const char **argv = NULL, *env[2];
+        char index[PATH_MAX];
+        va_list args;
+        int ret;
+        size_t i = 0, alloc = 0;
+
+        if (access(perf_path("hooks/%s", name), X_OK) < 0)
+                return 0;
+
+        va_start(args, name);
+        ALLOC_GROW(argv, i + 1, alloc);
+        argv[i++] = perf_path("hooks/%s", name);
+        while (argv[i-1]) {
+                ALLOC_GROW(argv, i + 1, alloc);
+                argv[i++] = va_arg(args, const char *);
+        }
+        va_end(args);
+
+        memset(&hook, 0, sizeof(hook));
+        hook.argv = argv;
+        hook.no_stdin = 1;
+        hook.stdout_to_stderr = 1;
+        if (index_file) {
+                snprintf(index, sizeof(index), "PERF_INDEX_FILE=%s", index_file);
+                env[0] = index;
+                env[1] = NULL;
+                hook.env = env;
+        }
+
+        ret = start_command(&hook);
+        free(argv);
+        if (ret) {
+                warning("Could not spawn %s", argv[0]);
+                return ret;
+        }
+        ret = finish_command(&hook);
+        if (ret == -ERR_RUN_COMMAND_WAITPID_SIGNAL)
+                warning("%s exited due to uncaught signal", argv[0]);
+
+        return ret;
+}