v4.19.13 snapshot.
diff --git a/tools/perf/builtin-help.c b/tools/perf/builtin-help.c
new file mode 100644
index 0000000..1c41b4e
--- /dev/null
+++ b/tools/perf/builtin-help.c
@@ -0,0 +1,493 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * builtin-help.c
+ *
+ * Builtin help command
+ */
+#include "perf.h"
+#include "util/config.h"
+#include "builtin.h"
+#include <subcmd/exec-cmd.h>
+#include "common-cmds.h"
+#include <subcmd/parse-options.h>
+#include <subcmd/run-command.h>
+#include <subcmd/help.h>
+#include "util/debug.h"
+#include <linux/kernel.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+static struct man_viewer_list {
+ struct man_viewer_list *next;
+ char name[0];
+} *man_viewer_list;
+
+static struct man_viewer_info_list {
+ struct man_viewer_info_list *next;
+ const char *info;
+ char name[0];
+} *man_viewer_info_list;
+
+enum help_format {
+ HELP_FORMAT_NONE,
+ HELP_FORMAT_MAN,
+ HELP_FORMAT_INFO,
+ HELP_FORMAT_WEB,
+};
+
+static enum help_format parse_help_format(const char *format)
+{
+ if (!strcmp(format, "man"))
+ return HELP_FORMAT_MAN;
+ if (!strcmp(format, "info"))
+ return HELP_FORMAT_INFO;
+ if (!strcmp(format, "web") || !strcmp(format, "html"))
+ return HELP_FORMAT_WEB;
+
+ pr_err("unrecognized help format '%s'", format);
+ return HELP_FORMAT_NONE;
+}
+
+static const char *get_man_viewer_info(const char *name)
+{
+ struct man_viewer_info_list *viewer;
+
+ for (viewer = man_viewer_info_list; viewer; viewer = viewer->next) {
+ if (!strcasecmp(name, viewer->name))
+ return viewer->info;
+ }
+ return NULL;
+}
+
+static int check_emacsclient_version(void)
+{
+ struct strbuf buffer = STRBUF_INIT;
+ struct child_process ec_process;
+ const char *argv_ec[] = { "emacsclient", "--version", NULL };
+ int version;
+ int ret = -1;
+
+ /* emacsclient prints its version number on stderr */
+ memset(&ec_process, 0, sizeof(ec_process));
+ ec_process.argv = argv_ec;
+ ec_process.err = -1;
+ ec_process.stdout_to_stderr = 1;
+ if (start_command(&ec_process)) {
+ fprintf(stderr, "Failed to start emacsclient.\n");
+ return -1;
+ }
+ if (strbuf_read(&buffer, ec_process.err, 20) < 0) {
+ fprintf(stderr, "Failed to read emacsclient version\n");
+ goto out;
+ }
+ close(ec_process.err);
+
+ /*
+ * Don't bother checking return value, because "emacsclient --version"
+ * seems to always exits with code 1.
+ */
+ finish_command(&ec_process);
+
+ if (!strstarts(buffer.buf, "emacsclient")) {
+ fprintf(stderr, "Failed to parse emacsclient version.\n");
+ goto out;
+ }
+
+ version = atoi(buffer.buf + strlen("emacsclient"));
+
+ if (version < 22) {
+ fprintf(stderr,
+ "emacsclient version '%d' too old (< 22).\n",
+ version);
+ } else
+ ret = 0;
+out:
+ strbuf_release(&buffer);
+ return ret;
+}
+
+static void exec_failed(const char *cmd)
+{
+ char sbuf[STRERR_BUFSIZE];
+ pr_warning("failed to exec '%s': %s", cmd, str_error_r(errno, sbuf, sizeof(sbuf)));
+}
+
+static void exec_woman_emacs(const char *path, const char *page)
+{
+ if (!check_emacsclient_version()) {
+ /* This works only with emacsclient version >= 22. */
+ char *man_page;
+
+ if (!path)
+ path = "emacsclient";
+ if (asprintf(&man_page, "(woman \"%s\")", page) > 0) {
+ execlp(path, "emacsclient", "-e", man_page, NULL);
+ free(man_page);
+ }
+ exec_failed(path);
+ }
+}
+
+static void exec_man_konqueror(const char *path, const char *page)
+{
+ const char *display = getenv("DISPLAY");
+
+ if (display && *display) {
+ char *man_page;
+ const char *filename = "kfmclient";
+
+ /* It's simpler to launch konqueror using kfmclient. */
+ if (path) {
+ const char *file = strrchr(path, '/');
+ if (file && !strcmp(file + 1, "konqueror")) {
+ char *new = strdup(path);
+ char *dest = strrchr(new, '/');
+
+ /* strlen("konqueror") == strlen("kfmclient") */
+ strcpy(dest + 1, "kfmclient");
+ path = new;
+ }
+ if (file)
+ filename = file;
+ } else
+ path = "kfmclient";
+ if (asprintf(&man_page, "man:%s(1)", page) > 0) {
+ execlp(path, filename, "newTab", man_page, NULL);
+ free(man_page);
+ }
+ exec_failed(path);
+ }
+}
+
+static void exec_man_man(const char *path, const char *page)
+{
+ if (!path)
+ path = "man";
+ execlp(path, "man", page, NULL);
+ exec_failed(path);
+}
+
+static void exec_man_cmd(const char *cmd, const char *page)
+{
+ char *shell_cmd;
+
+ if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
+ execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
+ free(shell_cmd);
+ }
+ exec_failed(cmd);
+}
+
+static void add_man_viewer(const char *name)
+{
+ struct man_viewer_list **p = &man_viewer_list;
+ size_t len = strlen(name);
+
+ while (*p)
+ p = &((*p)->next);
+ *p = zalloc(sizeof(**p) + len + 1);
+ strncpy((*p)->name, name, len);
+}
+
+static int supported_man_viewer(const char *name, size_t len)
+{
+ return (!strncasecmp("man", name, len) ||
+ !strncasecmp("woman", name, len) ||
+ !strncasecmp("konqueror", name, len));
+}
+
+static void do_add_man_viewer_info(const char *name,
+ size_t len,
+ const char *value)
+{
+ struct man_viewer_info_list *new = zalloc(sizeof(*new) + len + 1);
+
+ strncpy(new->name, name, len);
+ new->info = strdup(value);
+ new->next = man_viewer_info_list;
+ man_viewer_info_list = new;
+}
+
+static void unsupported_man_viewer(const char *name, const char *var)
+{
+ pr_warning("'%s': path for unsupported man viewer.\n"
+ "Please consider using 'man.<tool>.%s' instead.", name, var);
+}
+
+static int add_man_viewer_path(const char *name,
+ size_t len,
+ const char *value)
+{
+ if (supported_man_viewer(name, len))
+ do_add_man_viewer_info(name, len, value);
+ else
+ unsupported_man_viewer(name, "cmd");
+
+ return 0;
+}
+
+static int add_man_viewer_cmd(const char *name,
+ size_t len,
+ const char *value)
+{
+ if (supported_man_viewer(name, len))
+ unsupported_man_viewer(name, "path");
+ else
+ do_add_man_viewer_info(name, len, value);
+
+ return 0;
+}
+
+static int add_man_viewer_info(const char *var, const char *value)
+{
+ const char *name = var + 4;
+ const char *subkey = strrchr(name, '.');
+
+ if (!subkey) {
+ pr_err("Config with no key for man viewer: %s", name);
+ return -1;
+ }
+
+ if (!strcmp(subkey, ".path")) {
+ if (!value)
+ return config_error_nonbool(var);
+ return add_man_viewer_path(name, subkey - name, value);
+ }
+ if (!strcmp(subkey, ".cmd")) {
+ if (!value)
+ return config_error_nonbool(var);
+ return add_man_viewer_cmd(name, subkey - name, value);
+ }
+
+ pr_warning("'%s': unsupported man viewer sub key.", subkey);
+ return 0;
+}
+
+static int perf_help_config(const char *var, const char *value, void *cb)
+{
+ enum help_format *help_formatp = cb;
+
+ if (!strcmp(var, "help.format")) {
+ if (!value)
+ return config_error_nonbool(var);
+ *help_formatp = parse_help_format(value);
+ if (*help_formatp == HELP_FORMAT_NONE)
+ return -1;
+ return 0;
+ }
+ if (!strcmp(var, "man.viewer")) {
+ if (!value)
+ return config_error_nonbool(var);
+ add_man_viewer(value);
+ return 0;
+ }
+ if (strstarts(var, "man."))
+ return add_man_viewer_info(var, value);
+
+ return 0;
+}
+
+static struct cmdnames main_cmds, other_cmds;
+
+void list_common_cmds_help(void)
+{
+ unsigned int i, longest = 0;
+
+ for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
+ if (longest < strlen(common_cmds[i].name))
+ longest = strlen(common_cmds[i].name);
+ }
+
+ puts(" The most commonly used perf commands are:");
+ for (i = 0; i < ARRAY_SIZE(common_cmds); i++) {
+ printf(" %-*s ", longest, common_cmds[i].name);
+ puts(common_cmds[i].help);
+ }
+}
+
+static const char *cmd_to_page(const char *perf_cmd)
+{
+ char *s;
+
+ if (!perf_cmd)
+ return "perf";
+ else if (strstarts(perf_cmd, "perf"))
+ return perf_cmd;
+
+ return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
+}
+
+static void setup_man_path(void)
+{
+ char *new_path;
+ const char *old_path = getenv("MANPATH");
+
+ /* We should always put ':' after our path. If there is no
+ * old_path, the ':' at the end will let 'man' to try
+ * system-wide paths after ours to find the manual page. If
+ * there is old_path, we need ':' as delimiter. */
+ if (asprintf(&new_path, "%s:%s", system_path(PERF_MAN_PATH), old_path ?: "") > 0) {
+ setenv("MANPATH", new_path, 1);
+ free(new_path);
+ } else {
+ pr_err("Unable to setup man path");
+ }
+}
+
+static void exec_viewer(const char *name, const char *page)
+{
+ const char *info = get_man_viewer_info(name);
+
+ if (!strcasecmp(name, "man"))
+ exec_man_man(info, page);
+ else if (!strcasecmp(name, "woman"))
+ exec_woman_emacs(info, page);
+ else if (!strcasecmp(name, "konqueror"))
+ exec_man_konqueror(info, page);
+ else if (info)
+ exec_man_cmd(info, page);
+ else
+ pr_warning("'%s': unknown man viewer.", name);
+}
+
+static int show_man_page(const char *perf_cmd)
+{
+ struct man_viewer_list *viewer;
+ const char *page = cmd_to_page(perf_cmd);
+ const char *fallback = getenv("PERF_MAN_VIEWER");
+
+ setup_man_path();
+ for (viewer = man_viewer_list; viewer; viewer = viewer->next)
+ exec_viewer(viewer->name, page); /* will return when unable */
+
+ if (fallback)
+ exec_viewer(fallback, page);
+ exec_viewer("man", page);
+
+ pr_err("no man viewer handled the request");
+ return -1;
+}
+
+static int show_info_page(const char *perf_cmd)
+{
+ const char *page = cmd_to_page(perf_cmd);
+ setenv("INFOPATH", system_path(PERF_INFO_PATH), 1);
+ execlp("info", "info", "perfman", page, NULL);
+ return -1;
+}
+
+static int get_html_page_path(char **page_path, const char *page)
+{
+ struct stat st;
+ const char *html_path = system_path(PERF_HTML_PATH);
+
+ /* Check that we have a perf documentation directory. */
+ if (stat(mkpath("%s/perf.html", html_path), &st)
+ || !S_ISREG(st.st_mode)) {
+ pr_err("'%s': not a documentation directory.", html_path);
+ return -1;
+ }
+
+ return asprintf(page_path, "%s/%s.html", html_path, page);
+}
+
+/*
+ * If open_html is not defined in a platform-specific way (see for
+ * example compat/mingw.h), we use the script web--browse to display
+ * HTML.
+ */
+#ifndef open_html
+static void open_html(const char *path)
+{
+ execl_cmd("web--browse", "-c", "help.browser", path, NULL);
+}
+#endif
+
+static int show_html_page(const char *perf_cmd)
+{
+ const char *page = cmd_to_page(perf_cmd);
+ char *page_path; /* it leaks but we exec bellow */
+
+ if (get_html_page_path(&page_path, page) < 0)
+ return -1;
+
+ open_html(page_path);
+
+ return 0;
+}
+
+int cmd_help(int argc, const char **argv)
+{
+ bool show_all = false;
+ enum help_format help_format = HELP_FORMAT_MAN;
+ struct option builtin_help_options[] = {
+ OPT_BOOLEAN('a', "all", &show_all, "print all available commands"),
+ OPT_SET_UINT('m', "man", &help_format, "show man page", HELP_FORMAT_MAN),
+ OPT_SET_UINT('w', "web", &help_format, "show manual in web browser",
+ HELP_FORMAT_WEB),
+ OPT_SET_UINT('i', "info", &help_format, "show info page",
+ HELP_FORMAT_INFO),
+ OPT_END(),
+ };
+ const char * const builtin_help_subcommands[] = {
+ "buildid-cache", "buildid-list", "diff", "evlist", "help", "list",
+ "record", "report", "bench", "stat", "timechart", "top", "annotate",
+ "script", "sched", "kallsyms", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
+#ifdef HAVE_LIBELF_SUPPORT
+ "probe",
+#endif
+#if defined(HAVE_LIBAUDIT_SUPPORT) || defined(HAVE_SYSCALL_TABLE_SUPPORT)
+ "trace",
+#endif
+ NULL };
+ const char *builtin_help_usage[] = {
+ "perf help [--all] [--man|--web|--info] [command]",
+ NULL
+ };
+ int rc;
+
+ load_command_list("perf-", &main_cmds, &other_cmds);
+
+ rc = perf_config(perf_help_config, &help_format);
+ if (rc)
+ return rc;
+
+ argc = parse_options_subcommand(argc, argv, builtin_help_options,
+ builtin_help_subcommands, builtin_help_usage, 0);
+
+ if (show_all) {
+ printf("\n Usage: %s\n\n", perf_usage_string);
+ list_commands("perf commands", &main_cmds, &other_cmds);
+ printf(" %s\n\n", perf_more_info_string);
+ return 0;
+ }
+
+ if (!argv[0]) {
+ printf("\n usage: %s\n\n", perf_usage_string);
+ list_common_cmds_help();
+ printf("\n %s\n\n", perf_more_info_string);
+ return 0;
+ }
+
+ switch (help_format) {
+ case HELP_FORMAT_MAN:
+ rc = show_man_page(argv[0]);
+ break;
+ case HELP_FORMAT_INFO:
+ rc = show_info_page(argv[0]);
+ break;
+ case HELP_FORMAT_WEB:
+ rc = show_html_page(argv[0]);
+ break;
+ case HELP_FORMAT_NONE:
+ /* fall-through */
+ default:
+ rc = -1;
+ break;
+ }
+
+ return rc;
+}