xref: /openbmc/linux/tools/perf/perf.c (revision 78c99ba1)
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 
16 const char perf_usage_string[] =
17 	"perf [--version] [--help] COMMAND [ARGS]";
18 
19 const char perf_more_info_string[] =
20 	"See 'perf help COMMAND' for more information on a specific command.";
21 
22 static int use_pager = -1;
23 struct pager_config {
24 	const char *cmd;
25 	int val;
26 };
27 
28 static int pager_command_config(const char *var, const char *value, void *data)
29 {
30 	struct pager_config *c = data;
31 	if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
32 		c->val = perf_config_bool(var, value);
33 	return 0;
34 }
35 
36 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
37 int check_pager_config(const char *cmd)
38 {
39 	struct pager_config c;
40 	c.cmd = cmd;
41 	c.val = -1;
42 	perf_config(pager_command_config, &c);
43 	return c.val;
44 }
45 
46 static void commit_pager_choice(void) {
47 	switch (use_pager) {
48 	case 0:
49 		setenv("PERF_PAGER", "cat", 1);
50 		break;
51 	case 1:
52 		/* setup_pager(); */
53 		break;
54 	default:
55 		break;
56 	}
57 }
58 
59 static int handle_options(const char*** argv, int* argc, int* envchanged)
60 {
61 	int handled = 0;
62 
63 	while (*argc > 0) {
64 		const char *cmd = (*argv)[0];
65 		if (cmd[0] != '-')
66 			break;
67 
68 		/*
69 		 * For legacy reasons, the "version" and "help"
70 		 * commands can be written with "--" prepended
71 		 * to make them look like flags.
72 		 */
73 		if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
74 			break;
75 
76 		/*
77 		 * Check remaining flags.
78 		 */
79 		if (!prefixcmp(cmd, "--exec-path")) {
80 			cmd += 11;
81 			if (*cmd == '=')
82 				perf_set_argv_exec_path(cmd + 1);
83 			else {
84 				puts(perf_exec_path());
85 				exit(0);
86 			}
87 		} else if (!strcmp(cmd, "--html-path")) {
88 			puts(system_path(PERF_HTML_PATH));
89 			exit(0);
90 		} else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
91 			use_pager = 1;
92 		} else if (!strcmp(cmd, "--no-pager")) {
93 			use_pager = 0;
94 			if (envchanged)
95 				*envchanged = 1;
96 		} else if (!strcmp(cmd, "--perf-dir")) {
97 			if (*argc < 2) {
98 				fprintf(stderr, "No directory given for --perf-dir.\n" );
99 				usage(perf_usage_string);
100 			}
101 			setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
102 			if (envchanged)
103 				*envchanged = 1;
104 			(*argv)++;
105 			(*argc)--;
106 			handled++;
107 		} else if (!prefixcmp(cmd, "--perf-dir=")) {
108 			setenv(PERF_DIR_ENVIRONMENT, cmd + 10, 1);
109 			if (envchanged)
110 				*envchanged = 1;
111 		} else if (!strcmp(cmd, "--work-tree")) {
112 			if (*argc < 2) {
113 				fprintf(stderr, "No directory given for --work-tree.\n" );
114 				usage(perf_usage_string);
115 			}
116 			setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
117 			if (envchanged)
118 				*envchanged = 1;
119 			(*argv)++;
120 			(*argc)--;
121 		} else if (!prefixcmp(cmd, "--work-tree=")) {
122 			setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
123 			if (envchanged)
124 				*envchanged = 1;
125 		} else {
126 			fprintf(stderr, "Unknown option: %s\n", cmd);
127 			usage(perf_usage_string);
128 		}
129 
130 		(*argv)++;
131 		(*argc)--;
132 		handled++;
133 	}
134 	return handled;
135 }
136 
137 static int handle_alias(int *argcp, const char ***argv)
138 {
139 	int envchanged = 0, ret = 0, saved_errno = errno;
140 	int count, option_count;
141 	const char** new_argv;
142 	const char *alias_command;
143 	char *alias_string;
144 
145 	alias_command = (*argv)[0];
146 	alias_string = alias_lookup(alias_command);
147 	if (alias_string) {
148 		if (alias_string[0] == '!') {
149 			if (*argcp > 1) {
150 				struct strbuf buf;
151 
152 				strbuf_init(&buf, PATH_MAX);
153 				strbuf_addstr(&buf, alias_string);
154 				sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
155 				free(alias_string);
156 				alias_string = buf.buf;
157 			}
158 			ret = system(alias_string + 1);
159 			if (ret >= 0 && WIFEXITED(ret) &&
160 			    WEXITSTATUS(ret) != 127)
161 				exit(WEXITSTATUS(ret));
162 			die("Failed to run '%s' when expanding alias '%s'",
163 			    alias_string + 1, alias_command);
164 		}
165 		count = split_cmdline(alias_string, &new_argv);
166 		if (count < 0)
167 			die("Bad alias.%s string", alias_command);
168 		option_count = handle_options(&new_argv, &count, &envchanged);
169 		if (envchanged)
170 			die("alias '%s' changes environment variables\n"
171 				 "You can use '!perf' in the alias to do this.",
172 				 alias_command);
173 		memmove(new_argv - option_count, new_argv,
174 				count * sizeof(char *));
175 		new_argv -= option_count;
176 
177 		if (count < 1)
178 			die("empty alias for %s", alias_command);
179 
180 		if (!strcmp(alias_command, new_argv[0]))
181 			die("recursive alias: %s", alias_command);
182 
183 		new_argv = realloc(new_argv, sizeof(char*) *
184 				    (count + *argcp + 1));
185 		/* insert after command name */
186 		memcpy(new_argv + count, *argv + 1, sizeof(char*) * *argcp);
187 		new_argv[count+*argcp] = NULL;
188 
189 		*argv = new_argv;
190 		*argcp += count - 1;
191 
192 		ret = 1;
193 	}
194 
195 	errno = saved_errno;
196 
197 	return ret;
198 }
199 
200 const char perf_version_string[] = PERF_VERSION;
201 
202 #define RUN_SETUP	(1<<0)
203 #define USE_PAGER	(1<<1)
204 /*
205  * require working tree to be present -- anything uses this needs
206  * RUN_SETUP for reading from the configuration file.
207  */
208 #define NEED_WORK_TREE	(1<<2)
209 
210 struct cmd_struct {
211 	const char *cmd;
212 	int (*fn)(int, const char **, const char *);
213 	int option;
214 };
215 
216 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
217 {
218 	int status;
219 	struct stat st;
220 	const char *prefix;
221 
222 	prefix = NULL;
223 	if (p->option & RUN_SETUP)
224 		prefix = NULL; /* setup_perf_directory(); */
225 
226 	if (use_pager == -1 && p->option & RUN_SETUP)
227 		use_pager = check_pager_config(p->cmd);
228 	if (use_pager == -1 && p->option & USE_PAGER)
229 		use_pager = 1;
230 	commit_pager_choice();
231 
232 	if (p->option & NEED_WORK_TREE)
233 		/* setup_work_tree() */;
234 
235 	status = p->fn(argc, argv, prefix);
236 	if (status)
237 		return status & 0xff;
238 
239 	/* Somebody closed stdout? */
240 	if (fstat(fileno(stdout), &st))
241 		return 0;
242 	/* Ignore write errors for pipes and sockets.. */
243 	if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
244 		return 0;
245 
246 	/* Check for ENOSPC and EIO errors.. */
247 	if (fflush(stdout))
248 		die("write failure on standard output: %s", strerror(errno));
249 	if (ferror(stdout))
250 		die("unknown write failure on standard output");
251 	if (fclose(stdout))
252 		die("close failed on standard output: %s", strerror(errno));
253 	return 0;
254 }
255 
256 static void handle_internal_command(int argc, const char **argv)
257 {
258 	const char *cmd = argv[0];
259 	static struct cmd_struct commands[] = {
260 		{ "help", cmd_help, 0 },
261 		{ "list", cmd_list, 0 },
262 		{ "record", cmd_record, 0 },
263 		{ "report", cmd_report, 0 },
264 		{ "stat", cmd_stat, 0 },
265 		{ "top", cmd_top, 0 },
266 		{ "annotate", cmd_annotate, 0 },
267 		{ "version", cmd_version, 0 },
268 	};
269 	int i;
270 	static const char ext[] = STRIP_EXTENSION;
271 
272 	if (sizeof(ext) > 1) {
273 		i = strlen(argv[0]) - strlen(ext);
274 		if (i > 0 && !strcmp(argv[0] + i, ext)) {
275 			char *argv0 = strdup(argv[0]);
276 			argv[0] = cmd = argv0;
277 			argv0[i] = '\0';
278 		}
279 	}
280 
281 	/* Turn "perf cmd --help" into "perf help cmd" */
282 	if (argc > 1 && !strcmp(argv[1], "--help")) {
283 		argv[1] = argv[0];
284 		argv[0] = cmd = "help";
285 	}
286 
287 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
288 		struct cmd_struct *p = commands+i;
289 		if (strcmp(p->cmd, cmd))
290 			continue;
291 		exit(run_builtin(p, argc, argv));
292 	}
293 }
294 
295 static void execv_dashed_external(const char **argv)
296 {
297 	struct strbuf cmd = STRBUF_INIT;
298 	const char *tmp;
299 	int status;
300 
301 	strbuf_addf(&cmd, "perf-%s", argv[0]);
302 
303 	/*
304 	 * argv[0] must be the perf command, but the argv array
305 	 * belongs to the caller, and may be reused in
306 	 * subsequent loop iterations. Save argv[0] and
307 	 * restore it on error.
308 	 */
309 	tmp = argv[0];
310 	argv[0] = cmd.buf;
311 
312 	/*
313 	 * if we fail because the command is not found, it is
314 	 * OK to return. Otherwise, we just pass along the status code.
315 	 */
316 	status = run_command_v_opt(argv, 0);
317 	if (status != -ERR_RUN_COMMAND_EXEC) {
318 		if (IS_RUN_COMMAND_ERR(status))
319 			die("unable to run '%s'", argv[0]);
320 		exit(-status);
321 	}
322 	errno = ENOENT; /* as if we called execvp */
323 
324 	argv[0] = tmp;
325 
326 	strbuf_release(&cmd);
327 }
328 
329 static int run_argv(int *argcp, const char ***argv)
330 {
331 	int done_alias = 0;
332 
333 	while (1) {
334 		/* See if it's an internal command */
335 		handle_internal_command(*argcp, *argv);
336 
337 		/* .. then try the external ones */
338 		execv_dashed_external(*argv);
339 
340 		/* It could be an alias -- this works around the insanity
341 		 * of overriding "perf log" with "perf show" by having
342 		 * alias.log = show
343 		 */
344 		if (done_alias || !handle_alias(argcp, argv))
345 			break;
346 		done_alias = 1;
347 	}
348 
349 	return done_alias;
350 }
351 
352 
353 int main(int argc, const char **argv)
354 {
355 	const char *cmd;
356 
357 	cmd = perf_extract_argv0_path(argv[0]);
358 	if (!cmd)
359 		cmd = "perf-help";
360 
361 	/*
362 	 * "perf-xxxx" is the same as "perf xxxx", but we obviously:
363 	 *
364 	 *  - cannot take flags in between the "perf" and the "xxxx".
365 	 *  - cannot execute it externally (since it would just do
366 	 *    the same thing over again)
367 	 *
368 	 * So we just directly call the internal command handler, and
369 	 * die if that one cannot handle it.
370 	 */
371 	if (!prefixcmp(cmd, "perf-")) {
372 		cmd += 5;
373 		argv[0] = cmd;
374 		handle_internal_command(argc, argv);
375 		die("cannot handle %s internally", cmd);
376 	}
377 
378 	/* Look for flags.. */
379 	argv++;
380 	argc--;
381 	handle_options(&argv, &argc, NULL);
382 	commit_pager_choice();
383 	if (argc > 0) {
384 		if (!prefixcmp(argv[0], "--"))
385 			argv[0] += 2;
386 	} else {
387 		/* The user didn't specify a command; give them help */
388 		printf("\n usage: %s\n\n", perf_usage_string);
389 		list_common_cmds_help();
390 		printf("\n %s\n\n", perf_more_info_string);
391 		exit(1);
392 	}
393 	cmd = argv[0];
394 
395 	/*
396 	 * We use PATH to find perf commands, but we prepend some higher
397 	 * precidence paths: the "--exec-path" option, the PERF_EXEC_PATH
398 	 * environment, and the $(perfexecdir) from the Makefile at build
399 	 * time.
400 	 */
401 	setup_path();
402 
403 	while (1) {
404 		static int done_help = 0;
405 		static int was_alias = 0;
406 
407 		was_alias = run_argv(&argc, &argv);
408 		if (errno != ENOENT)
409 			break;
410 
411 		if (was_alias) {
412 			fprintf(stderr, "Expansion of alias '%s' failed; "
413 				"'%s' is not a perf-command\n",
414 				cmd, argv[0]);
415 			exit(1);
416 		}
417 		if (!done_help) {
418 			cmd = argv[0] = help_unknown_cmd(cmd);
419 			done_help = 1;
420 		} else
421 			break;
422 	}
423 
424 	fprintf(stderr, "Failed to run command '%s': %s\n",
425 		cmd, strerror(errno));
426 
427 	return 1;
428 }
429