perf tools: Do not manually count string lengths

Use strlen & macros instead of manually counting string lengths as
this is error prone and may lend to bugs.

Signed-off-by: Vincent Legoll <vincent.legoll@gmail.com>
Cc: Linus Torvalds <torvalds@osdl.org>
LKML-Reference: <4727185d0910130118m5387058dndb02ac9b384af9f0@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 13 insertions, 8 deletions

diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 19fc7feb9d59..624e62d9d1e0 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -89,8 +89,8 @@ static int handle_options(const char*** argv, int* argc, int* envchanged)
                 /*
                  * Check remaining flags.
                  */
-                if (!prefixcmp(cmd, "--exec-path")) {
-                        cmd += 11;
+                if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
+                        cmd += strlen(CMD_EXEC_PATH);
                         if (*cmd == '=')
                                 perf_set_argv_exec_path(cmd + 1);
                         else {
@@ -117,8 +117,8 @@ static int handle_options(const char*** argv, int* argc, int* envchanged)
                         (*argv)++;
                         (*argc)--;
                         handled++;
-                } else if (!prefixcmp(cmd, "--perf-dir=")) {
-                        setenv(PERF_DIR_ENVIRONMENT, cmd + 10, 1);
+                } else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
+                        setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
                         if (envchanged)
                                 *envchanged = 1;
                 } else if (!strcmp(cmd, "--work-tree")) {
@@ -131,8 +131,8 @@ static int handle_options(const char*** argv, int* argc, int* envchanged)
                                 *envchanged = 1;
                         (*argv)++;
                         (*argc)--;
-                } else if (!prefixcmp(cmd, "--work-tree=")) {
-                        setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + 12, 1);
+                } else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
+                        setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
                         if (envchanged)
                                 *envchanged = 1;
                 } else if (!strcmp(cmd, "--debugfs-dir")) {
@@ -146,8 +146,8 @@ static int handle_options(const char*** argv, int* argc, int* envchanged)
                                 *envchanged = 1;
                         (*argv)++;
                         (*argc)--;
-                } else if (!prefixcmp(cmd, "--debugfs-dir=")) {
-                        strncpy(debugfs_mntpt, cmd + 14, MAXPATHLEN);
+                } else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
+                        strncpy(debugfs_mntpt, cmd + strlen(CMD_DEBUGFS_DIR), MAXPATHLEN);
                         debugfs_mntpt[MAXPATHLEN - 1] = '\0';
                         if (envchanged)
                                 *envchanged = 1;
diff --git a/tools/perf/util/cache.h b/tools/perf/util/cache.h
index f26172c0c919..918eb376abe3 100644
--- a/tools/perf/util/cache.h
+++ b/tools/perf/util/cache.h
@@ -5,6 +5,11 @@
 #include "strbuf.h"
 #include "../perf.h"
 
+#define CMD_EXEC_PATH "--exec-path"
+#define CMD_PERF_DIR "--perf-dir="
+#define CMD_WORK_TREE "--work-tree="
+#define CMD_DEBUGFS_DIR "--debugfs-dir="
+
 #define PERF_DIR_ENVIRONMENT "PERF_DIR"
 #define PERF_WORK_TREE_ENVIRONMENT "PERF_WORK_TREE"
 #define DEFAULT_PERF_DIR_ENVIRONMENT ".perf"