linux/tools/perf/builtin-help.c
Arnaldo Carvalho de Melo c8b5f2c96d tools: Introduce str_error_r()
The tools so far have been using the strerror_r() GNU variant, that
returns a string, be it the buffer passed or something else.

But that, besides being tricky in cases where we expect that the
function using strerror_r() returns the error formatted in a provided
buffer (we have to check if it returned something else and copy that
instead), breaks the build on systems not using glibc, like Alpine
Linux, where musl libc is used.

So, introduce yet another wrapper, str_error_r(), that has the GNU
interface, but uses the portable XSI variant of strerror_r(), so that
users rest asured that the provided buffer is used and it is what is
returned.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-12 15:19:47 -03:00

498 lines
12 KiB
C

/*
* 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"
static struct man_viewer_list {
struct man_viewer_list *next;
char name[FLEX_ARRAY];
} *man_viewer_list;
static struct man_viewer_info_list {
struct man_viewer_info_list *next;
const char *info;
char name[FLEX_ARRAY];
} *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 (prefixcmp(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_woman_emacs(const char *path, const char *page)
{
char sbuf[STRERR_BUFSIZE];
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);
}
warning("failed to exec '%s': %s", path,
str_error_r(errno, sbuf, sizeof(sbuf)));
}
}
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";
char sbuf[STRERR_BUFSIZE];
/* 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);
}
warning("failed to exec '%s': %s", path,
str_error_r(errno, sbuf, sizeof(sbuf)));
}
}
static void exec_man_man(const char *path, const char *page)
{
char sbuf[STRERR_BUFSIZE];
if (!path)
path = "man";
execlp(path, "man", page, NULL);
warning("failed to exec '%s': %s", path,
str_error_r(errno, sbuf, sizeof(sbuf)));
}
static void exec_man_cmd(const char *cmd, const char *page)
{
char sbuf[STRERR_BUFSIZE];
char *shell_cmd;
if (asprintf(&shell_cmd, "%s %s", cmd, page) > 0) {
execl("/bin/sh", "sh", "-c", shell_cmd, NULL);
free(shell_cmd);
}
warning("failed to exec '%s': %s", cmd,
str_error_r(errno, sbuf, sizeof(sbuf)));
}
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 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
warning("'%s': path for unsupported man viewer.\n"
"Please consider using 'man.<tool>.cmd' instead.",
name);
return 0;
}
static int add_man_viewer_cmd(const char *name,
size_t len,
const char *value)
{
if (supported_man_viewer(name, len))
warning("'%s': cmd for supported man viewer.\n"
"Please consider using 'man.<tool>.path' instead.",
name);
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)
return error("Config with no key for man viewer: %s", name);
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);
}
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 (!prefixcmp(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 int is_perf_command(const char *s)
{
return is_in_cmdlist(&main_cmds, s) ||
is_in_cmdlist(&other_cmds, s);
}
static const char *cmd_to_page(const char *perf_cmd)
{
char *s;
if (!perf_cmd)
return "perf";
else if (!prefixcmp(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 {
error("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
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, const char *prefix __maybe_unused)
{
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", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
#ifdef HAVE_LIBELF_SUPPORT
"probe",
#endif
#ifdef HAVE_LIBAUDIT_SUPPORT
"trace",
#endif
NULL };
const char *builtin_help_usage[] = {
"perf help [--all] [--man|--web|--info] [command]",
NULL
};
const char *alias;
int rc = 0;
load_command_list("perf-", &main_cmds, &other_cmds);
perf_config(perf_help_config, &help_format);
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;
}
alias = alias_lookup(argv[0]);
if (alias && !is_perf_command(argv[0])) {
printf("`perf %s' is aliased to `%s'\n", argv[0], alias);
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;
}