perf help: Use asprintf instead of adhoc equivalents

That doesn't chekcs malloc return and that, when using strbuf, if it
can't grow, just explodes away via die().

Cc: Adrian Hunter <adrian.hunter@intel.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-vr8qsjbwub7e892hpa9msz95@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-help.c b/tools/perf/builtin-help.c
index 49d55e2..bc1de9b 100644 (file)
--- a/tools/perf/builtin-help.c
+++ b/tools/perf/builtin-help.c
@@ -106,12 +106,14 @@ static void exec_woman_emacs(const char *path, const char *page)
 
        if (!check_emacsclient_version()) {
                /* This works only with emacsclient version >= 22. */
-               struct strbuf man_page = STRBUF_INIT;
+               char *man_page;
 
                if (!path)
                        path = "emacsclient";
-               strbuf_addf(&man_page, "(woman \"%s\")", page);
-               execlp(path, "emacsclient", "-e", man_page.buf, NULL);
+               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,
                        strerror_r(errno, sbuf, sizeof(sbuf)));
        }
@@ -122,7 +124,7 @@ static void exec_man_konqueror(const char *path, const char *page)
        const char *display = getenv("DISPLAY");
 
        if (display && *display) {
-               struct strbuf man_page = STRBUF_INIT;
+               char *man_page;
                const char *filename = "kfmclient";
                char sbuf[STRERR_BUFSIZE];
 
@@ -141,8 +143,10 @@ static void exec_man_konqueror(const char *path, const char *page)
                                filename = file;
                } else
                        path = "kfmclient";
-               strbuf_addf(&man_page, "man:%s(1)", page);
-               execlp(path, filename, "newTab", man_page.buf, NULL);
+               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,
                        strerror_r(errno, sbuf, sizeof(sbuf)));
        }
@@ -161,11 +165,13 @@ static void exec_man_man(const char *path, const char *page)
 
 static void exec_man_cmd(const char *cmd, const char *page)
 {
-       struct strbuf shell_cmd = STRBUF_INIT;
        char sbuf[STRERR_BUFSIZE];
+       char *shell_cmd;
 
-       strbuf_addf(&shell_cmd, "%s %s", cmd, page);
-       execl("/bin/sh", "sh", "-c", shell_cmd.buf, NULL);
+       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,
                strerror_r(errno, sbuf, sizeof(sbuf)));
 }
@@ -299,43 +305,33 @@ static int is_perf_command(const char *s)
                is_in_cmdlist(&other_cmds, s);
 }
 
-static const char *prepend(const char *prefix, const char *cmd)
-{
-       size_t pre_len = strlen(prefix);
-       size_t cmd_len = strlen(cmd);
-       char *p = malloc(pre_len + cmd_len + 1);
-       memcpy(p, prefix, pre_len);
-       strcpy(p + pre_len, cmd);
-       return p;
-}
-
 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;
-       else
-               return prepend("perf-", perf_cmd);
+
+       return asprintf(&s, "perf-%s", perf_cmd) < 0 ? NULL : s;
 }
 
 static void setup_man_path(void)
 {
-       struct strbuf new_path = STRBUF_INIT;
+       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. */
-       strbuf_addstr(&new_path, system_path(PERF_MAN_PATH));
-       strbuf_addch(&new_path, ':');
-       if (old_path)
-               strbuf_addstr(&new_path, old_path);
-
-       setenv("MANPATH", new_path.buf, 1);
-
-       strbuf_release(&new_path);
+       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)
@@ -380,7 +376,7 @@ static int show_info_page(const char *perf_cmd)
        return -1;
 }
 
-static int get_html_page_path(struct strbuf *page_path, const char *page)
+static int get_html_page_path(char **page_path, const char *page)
 {
        struct stat st;
        const char *html_path = system_path(PERF_HTML_PATH);
@@ -392,10 +388,7 @@ static int get_html_page_path(struct strbuf *page_path, const char *page)
                return -1;
        }
 
-       strbuf_init(page_path, 0);
-       strbuf_addf(page_path, "%s/%s.html", html_path, page);
-
-       return 0;
+       return asprintf(page_path, "%s/%s.html", html_path, page);
 }
 
 /*
@@ -413,12 +406,12 @@ static void open_html(const char *path)
 static int show_html_page(const char *perf_cmd)
 {
        const char *page = cmd_to_page(perf_cmd);
-       struct strbuf page_path; /* it leaks but we exec bellow */
+       char *page_path; /* it leaks but we exec bellow */
 
-       if (get_html_page_path(&page_path, page) != 0)
+       if (get_html_page_path(&page_path, page) < 0)
                return -1;
 
-       open_html(page_path.buf);
+       open_html(page_path);
 
        return 0;
 }