perf tools: Don't die() in do_write()
[linux-2.6.git] / tools / perf / perf.c
1 /*
2  * perf.c
3  *
4  * Performance analysis utility.
5  *
6  * This is the main hub from which the sub-commands (perf stat,
7  * perf top, perf record, perf report, etc.) are started.
8  */
9 #include "builtin.h"
10
11 #include "util/exec_cmd.h"
12 #include "util/cache.h"
13 #include "util/quote.h"
14 #include "util/run-command.h"
15 #include "util/parse-events.h"
16 #include "util/string.h"
17 #include "util/debugfs.h"
18
19 const char perf_usage_string[] =
20         "perf [--version] [--help] COMMAND [ARGS]";
21
22 const char perf_more_info_string[] =
23         "See 'perf help COMMAND' for more information on a specific command.";
24
25 static int use_pager = -1;
26 struct pager_config {
27         const char *cmd;
28         int val;
29 };
30
31 static char debugfs_mntpt[MAXPATHLEN];
32
33 static int pager_command_config(const char *var, const char *value, void *data)
34 {
35         struct pager_config *c = data;
36         if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
37                 c->val = perf_config_bool(var, value);
38         return 0;
39 }
40
41 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
42 int check_pager_config(const char *cmd)
43 {
44         struct pager_config c;
45         c.cmd = cmd;
46         c.val = -1;
47         perf_config(pager_command_config, &c);
48         return c.val;
49 }
50
51 static void commit_pager_choice(void) {
52         switch (use_pager) {
53         case 0:
54                 setenv("PERF_PAGER", "cat", 1);
55                 break;
56         case 1:
57                 /* setup_pager(); */
58                 break;
59         default:
60                 break;
61         }
62 }
63
64 static void set_debugfs_path(void)
65 {
66         char *path;
67
68         path = getenv(PERF_DEBUGFS_ENVIRONMENT);
69         snprintf(debugfs_path, MAXPATHLEN, "%s/%s", path ?: debugfs_mntpt,
70                  "tracing/events");
71 }
72
73 static int handle_options(const char*** argv, int* argc, int* envchanged)
74 {
75         int handled = 0;
76
77         while (*argc > 0) {
78                 const char *cmd = (*argv)[0];
79                 if (cmd[0] != '-')
80                         break;
81
82                 /*
83                  * For legacy reasons, the "version" and "help"
84                  * commands can be written with "--" prepended
85                  * to make them look like flags.
86                  */
87                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
88                         break;
89
90                 /*
91                  * Check remaining flags.
92                  */
93                 if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
94                         cmd += strlen(CMD_EXEC_PATH);
95                         if (*cmd == '=')
96                                 perf_set_argv_exec_path(cmd + 1);
97                         else {
98                                 puts(perf_exec_path());
99                                 exit(0);
100                         }
101                 } else if (!strcmp(cmd, "--html-path")) {
102                         puts(system_path(PERF_HTML_PATH));
103                         exit(0);
104                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
105                         use_pager = 1;
106                 } else if (!strcmp(cmd, "--no-pager")) {
107                         use_pager = 0;
108                         if (envchanged)
109                                 *envchanged = 1;
110                 } else if (!strcmp(cmd, "--perf-dir")) {
111                         if (*argc < 2) {
112                                 fprintf(stderr, "No directory given for --perf-dir.\n" );
113                                 usage(perf_usage_string);
114                         }
115                         setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
116                         if (envchanged)
117                                 *envchanged = 1;
118                         (*argv)++;
119                         (*argc)--;
120                         handled++;
121                 } else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
122                         setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
123                         if (envchanged)
124                                 *envchanged = 1;
125                 } else if (!strcmp(cmd, "--work-tree")) {
126                         if (*argc < 2) {
127                                 fprintf(stderr, "No directory given for --work-tree.\n" );
128                                 usage(perf_usage_string);
129                         }
130                         setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
131                         if (envchanged)
132                                 *envchanged = 1;
133                         (*argv)++;
134                         (*argc)--;
135                 } else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
136                         setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
137                         if (envchanged)
138                                 *envchanged = 1;
139                 } else if (!strcmp(cmd, "--debugfs-dir")) {
140                         if (*argc < 2) {
141                                 fprintf(stderr, "No directory given for --debugfs-dir.\n");
142                                 usage(perf_usage_string);
143                         }
144                         strncpy(debugfs_mntpt, (*argv)[1], MAXPATHLEN);
145                         debugfs_mntpt[MAXPATHLEN - 1] = '\0';
146                         if (envchanged)
147                                 *envchanged = 1;
148                         (*argv)++;
149                         (*argc)--;
150                 } else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
151                         strncpy(debugfs_mntpt, cmd + strlen(CMD_DEBUGFS_DIR), MAXPATHLEN);
152                         debugfs_mntpt[MAXPATHLEN - 1] = '\0';
153                         if (envchanged)
154                                 *envchanged = 1;
155                 } else {
156                         fprintf(stderr, "Unknown option: %s\n", cmd);
157                         usage(perf_usage_string);
158                 }
159
160                 (*argv)++;
161                 (*argc)--;
162                 handled++;
163         }
164         return handled;
165 }
166
167 static int handle_alias(int *argcp, const char ***argv)
168 {
169         int envchanged = 0, ret = 0, saved_errno = errno;
170         int count, option_count;
171         const char** new_argv;
172         const char *alias_command;
173         char *alias_string;
174
175         alias_command = (*argv)[0];
176         alias_string = alias_lookup(alias_command);
177         if (alias_string) {
178                 if (alias_string[0] == '!') {
179                         if (*argcp > 1) {
180                                 struct strbuf buf;
181
182                                 strbuf_init(&buf, PATH_MAX);
183                                 strbuf_addstr(&buf, alias_string);
184                                 sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
185                                 free(alias_string);
186                                 alias_string = buf.buf;
187                         }
188                         ret = system(alias_string + 1);
189                         if (ret >= 0 && WIFEXITED(ret) &&
190                             WEXITSTATUS(ret) != 127)
191                                 exit(WEXITSTATUS(ret));
192                         die("Failed to run '%s' when expanding alias '%s'",
193                             alias_string + 1, alias_command);
194                 }
195                 count = split_cmdline(alias_string, &new_argv);
196                 if (count < 0)
197                         die("Bad alias.%s string", alias_command);
198                 option_count = handle_options(&new_argv, &count, &envchanged);
199                 if (envchanged)
200                         die("alias '%s' changes environment variables\n"
201                                  "You can use '!perf' in the alias to do this.",
202                                  alias_command);
203                 memmove(new_argv - option_count, new_argv,
204                                 count * sizeof(char *));
205                 new_argv -= option_count;
206
207                 if (count < 1)
208                         die("empty alias for %s", alias_command);
209
210                 if (!strcmp(alias_command, new_argv[0]))
211                         die("recursive alias: %s", alias_command);
212
213                 new_argv = realloc(new_argv, sizeof(char*) *
214                                     (count + *argcp + 1));
215                 /* insert after command name */
216                 memcpy(new_argv + count, *argv + 1, sizeof(char*) * *argcp);
217                 new_argv[count+*argcp] = NULL;
218
219                 *argv = new_argv;
220                 *argcp += count - 1;
221
222                 ret = 1;
223         }
224
225         errno = saved_errno;
226
227         return ret;
228 }
229
230 const char perf_version_string[] = PERF_VERSION;
231
232 #define RUN_SETUP       (1<<0)
233 #define USE_PAGER       (1<<1)
234 /*
235  * require working tree to be present -- anything uses this needs
236  * RUN_SETUP for reading from the configuration file.
237  */
238 #define NEED_WORK_TREE  (1<<2)
239
240 struct cmd_struct {
241         const char *cmd;
242         int (*fn)(int, const char **, const char *);
243         int option;
244 };
245
246 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
247 {
248         int status;
249         struct stat st;
250         const char *prefix;
251
252         prefix = NULL;
253         if (p->option & RUN_SETUP)
254                 prefix = NULL; /* setup_perf_directory(); */
255
256         if (use_pager == -1 && p->option & RUN_SETUP)
257                 use_pager = check_pager_config(p->cmd);
258         if (use_pager == -1 && p->option & USE_PAGER)
259                 use_pager = 1;
260         commit_pager_choice();
261         set_debugfs_path();
262
263         status = p->fn(argc, argv, prefix);
264         if (status)
265                 return status & 0xff;
266
267         /* Somebody closed stdout? */
268         if (fstat(fileno(stdout), &st))
269                 return 0;
270         /* Ignore write errors for pipes and sockets.. */
271         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
272                 return 0;
273
274         /* Check for ENOSPC and EIO errors.. */
275         if (fflush(stdout))
276                 die("write failure on standard output: %s", strerror(errno));
277         if (ferror(stdout))
278                 die("unknown write failure on standard output");
279         if (fclose(stdout))
280                 die("close failed on standard output: %s", strerror(errno));
281         return 0;
282 }
283
284 static void handle_internal_command(int argc, const char **argv)
285 {
286         const char *cmd = argv[0];
287         static struct cmd_struct commands[] = {
288                 { "help", cmd_help, 0 },
289                 { "list", cmd_list, 0 },
290                 { "buildid-list", cmd_buildid_list, 0 },
291                 { "record", cmd_record, 0 },
292                 { "report", cmd_report, 0 },
293                 { "bench", cmd_bench, 0 },
294                 { "stat", cmd_stat, 0 },
295                 { "timechart", cmd_timechart, 0 },
296                 { "top", cmd_top, 0 },
297                 { "annotate", cmd_annotate, 0 },
298                 { "version", cmd_version, 0 },
299                 { "trace", cmd_trace, 0 },
300                 { "sched", cmd_sched, 0 },
301         };
302         unsigned int i;
303         static const char ext[] = STRIP_EXTENSION;
304
305         if (sizeof(ext) > 1) {
306                 i = strlen(argv[0]) - strlen(ext);
307                 if (i > 0 && !strcmp(argv[0] + i, ext)) {
308                         char *argv0 = strdup(argv[0]);
309                         argv[0] = cmd = argv0;
310                         argv0[i] = '\0';
311                 }
312         }
313
314         /* Turn "perf cmd --help" into "perf help cmd" */
315         if (argc > 1 && !strcmp(argv[1], "--help")) {
316                 argv[1] = argv[0];
317                 argv[0] = cmd = "help";
318         }
319
320         for (i = 0; i < ARRAY_SIZE(commands); i++) {
321                 struct cmd_struct *p = commands+i;
322                 if (strcmp(p->cmd, cmd))
323                         continue;
324                 exit(run_builtin(p, argc, argv));
325         }
326 }
327
328 static void execv_dashed_external(const char **argv)
329 {
330         struct strbuf cmd = STRBUF_INIT;
331         const char *tmp;
332         int status;
333
334         strbuf_addf(&cmd, "perf-%s", argv[0]);
335
336         /*
337          * argv[0] must be the perf command, but the argv array
338          * belongs to the caller, and may be reused in
339          * subsequent loop iterations. Save argv[0] and
340          * restore it on error.
341          */
342         tmp = argv[0];
343         argv[0] = cmd.buf;
344
345         /*
346          * if we fail because the command is not found, it is
347          * OK to return. Otherwise, we just pass along the status code.
348          */
349         status = run_command_v_opt(argv, 0);
350         if (status != -ERR_RUN_COMMAND_EXEC) {
351                 if (IS_RUN_COMMAND_ERR(status))
352                         die("unable to run '%s'", argv[0]);
353                 exit(-status);
354         }
355         errno = ENOENT; /* as if we called execvp */
356
357         argv[0] = tmp;
358
359         strbuf_release(&cmd);
360 }
361
362 static int run_argv(int *argcp, const char ***argv)
363 {
364         int done_alias = 0;
365
366         while (1) {
367                 /* See if it's an internal command */
368                 handle_internal_command(*argcp, *argv);
369
370                 /* .. then try the external ones */
371                 execv_dashed_external(*argv);
372
373                 /* It could be an alias -- this works around the insanity
374                  * of overriding "perf log" with "perf show" by having
375                  * alias.log = show
376                  */
377                 if (done_alias || !handle_alias(argcp, argv))
378                         break;
379                 done_alias = 1;
380         }
381
382         return done_alias;
383 }
384
385 /* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
386 static void get_debugfs_mntpt(void)
387 {
388         const char *path = debugfs_find_mountpoint();
389
390         if (path)
391                 strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));
392         else
393                 debugfs_mntpt[0] = '\0';
394 }
395
396 int main(int argc, const char **argv)
397 {
398         const char *cmd;
399
400         cmd = perf_extract_argv0_path(argv[0]);
401         if (!cmd)
402                 cmd = "perf-help";
403         /* get debugfs mount point from /proc/mounts */
404         get_debugfs_mntpt();
405         /*
406          * "perf-xxxx" is the same as "perf xxxx", but we obviously:
407          *
408          *  - cannot take flags in between the "perf" and the "xxxx".
409          *  - cannot execute it externally (since it would just do
410          *    the same thing over again)
411          *
412          * So we just directly call the internal command handler, and
413          * die if that one cannot handle it.
414          */
415         if (!prefixcmp(cmd, "perf-")) {
416                 cmd += 5;
417                 argv[0] = cmd;
418                 handle_internal_command(argc, argv);
419                 die("cannot handle %s internally", cmd);
420         }
421
422         /* Look for flags.. */
423         argv++;
424         argc--;
425         handle_options(&argv, &argc, NULL);
426         commit_pager_choice();
427         set_debugfs_path();
428         if (argc > 0) {
429                 if (!prefixcmp(argv[0], "--"))
430                         argv[0] += 2;
431         } else {
432                 /* The user didn't specify a command; give them help */
433                 printf("\n usage: %s\n\n", perf_usage_string);
434                 list_common_cmds_help();
435                 printf("\n %s\n\n", perf_more_info_string);
436                 exit(1);
437         }
438         cmd = argv[0];
439
440         /*
441          * We use PATH to find perf commands, but we prepend some higher
442          * precidence paths: the "--exec-path" option, the PERF_EXEC_PATH
443          * environment, and the $(perfexecdir) from the Makefile at build
444          * time.
445          */
446         setup_path();
447
448         while (1) {
449                 static int done_help = 0;
450                 static int was_alias = 0;
451
452                 was_alias = run_argv(&argc, &argv);
453                 if (errno != ENOENT)
454                         break;
455
456                 if (was_alias) {
457                         fprintf(stderr, "Expansion of alias '%s' failed; "
458                                 "'%s' is not a perf-command\n",
459                                 cmd, argv[0]);
460                         exit(1);
461                 }
462                 if (!done_help) {
463                         cmd = argv[0] = help_unknown_cmd(cmd);
464                         done_help = 1;
465                 } else
466                         break;
467         }
468
469         fprintf(stderr, "Failed to run command '%s': %s\n",
470                 cmd, strerror(errno));
471
472         return 1;
473 }