perf tools: Replace basename() calls with perf_basename()

As noticed in a sashiko review for a patch adding a missing libgen.h
in a file using basename():

  https://sashiko.dev/#/patchset/20260402001740.2220481-1-acme%40kernel.org

So avoid these subtleties and instead reuse the gnu_basename() function
we had in srcline.c, renaming it to perf_basename() and replace
basename() calls with it, simplifying several cases by removing now
needless strdups.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

tools/perf/builtin-daemon.c

@@ -1016,7 +1016,7 @@ static int setup_config_changes(struct daemon *daemon)
 {
 	char *basen = strdup(daemon->config_real);
 	char *dirn  = strdup(daemon->config_real);
-	char *base, *dir;
+	const char *base, *dir;
 	int fd, wd = -1;
 
 	if (!dirn || !basen)
@@ -1029,7 +1029,7 @@ static int setup_config_changes(struct daemon *daemon)
 	}
 
 	dir = dirname(dirn);
-	base = basename(basen);
+	base = perf_basename(basen);
 	pr_debug("config file: %s, dir: %s\n", base, dir);
 
 	wd = inotify_add_watch(fd, dir, IN_CLOSE_WRITE);

tools/perf/util/annotate.c

@@ -8,7 +8,6 @@
 
 #include <errno.h>
 #include <inttypes.h>
-#include <libgen.h>
 #include <stdlib.h>
 #include "util.h" // hex_width()
 #include "ui/ui.h"
@@ -1245,7 +1244,7 @@ int hist_entry__annotate_printf(struct hist_entry *he, struct evsel *evsel)
 	if (opts->full_path)
 		d_filename = filename;
 	else
-		d_filename = basename(filename);
+		d_filename = perf_basename(filename);
 
 	if (evsel__is_group_event(evsel)) {
 		evsel__group_desc(evsel, buf, sizeof(buf));

tools/perf/util/data-convert-json.c

@@ -326,7 +326,7 @@ static void output_headers(struct perf_session *session, struct convert_json *c)
 	output_json_format(out, false, 2, "]");
 }
 
-int bt_convert__perf2json(const char *input_name, const char *output_name,
+int bt_convert__perf2json(const char *_input_name, const char *output_name,
 		struct perf_data_convert_opts *opts __maybe_unused)
 {
 	struct perf_session *session;
@@ -342,7 +342,7 @@ int bt_convert__perf2json(const char *input_name, const char *output_name,
 	};
 	struct perf_data data = {
 		.mode = PERF_DATA_MODE_READ,
-		.path = input_name,
+		.path = _input_name,
 		.force = opts->force,
 	};
 

tools/perf/util/dsos.c

@@ -6,7 +6,6 @@
 #include "vdso.h"
 #include "namespaces.h"
 #include <errno.h>
-#include <libgen.h>
 #include <stdlib.h>
 #include <string.h>
 #include <symbol.h> // filename__read_build_id
@@ -297,34 +296,21 @@ struct dso *dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
 
 static void dso__set_basename(struct dso *dso)
 {
-	char *base, *lname;
+	bool allocated = false;
+	const char *base;
 	int tid;
 
 	if (perf_pid_map_tid(dso__long_name(dso), &tid)) {
-		if (asprintf(&base, "[JIT] tid %d", tid) < 0)
+		char *jitname;
+
+		if (asprintf(&jitname, "[JIT] tid %d", tid) < 0)
 			return;
+		allocated = true;
+		base = jitname;
 	} else {
-	      /*
-	       * basename() may modify path buffer, so we must pass
-               * a copy.
-               */
-		lname = strdup(dso__long_name(dso));
-		if (!lname)
-			return;
-
-		/*
-		 * basename() may return a pointer to internal
-		 * storage which is reused in subsequent calls
-		 * so copy the result.
-		 */
-		base = strdup(basename(lname));
-
-		free(lname);
-
-		if (!base)
-			return;
+		base = perf_basename(dso__long_name(dso));
 	}
-	dso__set_short_name(dso, base, true);
+	dso__set_short_name(dso, base, allocated);
 }
 
 static struct dso *__dsos__addnew_id(struct dsos *dsos, const char *name, const struct dso_id *id)

tools/perf/util/probe-event.c

@@ -11,7 +11,6 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <errno.h>
-#include <libgen.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <stdlib.h>
@@ -229,7 +228,7 @@ static int convert_exec_to_group(const char *exec, char **result)
 	if (!exec_copy)
 		return -ENOMEM;
 
-	ptr1 = basename(exec_copy);
+	ptr1 = (char *)perf_basename(exec_copy);
 	if (!ptr1) {
 		ret = -EINVAL;
 		goto out;

tools/perf/util/srcline.c

@@ -8,6 +8,7 @@
 #include "symbol.h"
 #include "libdw.h"
 #include "debug.h"
+#include "util.h"
 
 #include <inttypes.h>
 #include <string.h>
@@ -74,14 +75,6 @@ int inline_list__append_tail(struct symbol *symbol, char *srcline, struct inline
 	return 0;
 }
 
-/* basename version that takes a const input string */
-static const char *gnu_basename(const char *path)
-{
-	const char *base = strrchr(path, '/');
-
-	return base ? base + 1 : path;
-}
-
 char *srcline_from_fileline(const char *file, unsigned int line)
 {
 	char *srcline;
@@ -90,7 +83,7 @@ char *srcline_from_fileline(const char *file, unsigned int line)
 		return NULL;
 
 	if (!srcline_full_filename)
-		file = gnu_basename(file);
+		file = perf_basename(file);
 
 	if (asprintf(&srcline, "%s:%u", file, line) < 0)
 		return NULL;

tools/perf/util/symbol.h

@@ -14,6 +14,7 @@
 #include "path.h"
 #include "symbol_conf.h"
 #include "spark.h"
+#include "util.h"
 
 #ifdef HAVE_LIBELF_SUPPORT
 #include <libelf.h>
@@ -97,18 +98,9 @@ struct intlist;
 
 static inline int __symbol__join_symfs(char *bf, size_t size, const char *path)
 {
-	if (symbol_conf.symfs_layout_flat) {
-		char *path_copy = strdup(path);
-		char *base;
-		int ret;
+	if (symbol_conf.symfs_layout_flat)
+		return path__join(bf, size, symbol_conf.symfs, perf_basename(path));
 
-		if (!path_copy)
-			return -ENOMEM;
-		base = basename(path_copy);
-		ret = path__join(bf, size, symbol_conf.symfs, base);
-		free(path_copy);
-		return ret;
-	}
 	return path__join(bf, size, symbol_conf.symfs, path);
 }
 

tools/perf/util/util.c

@@ -545,3 +545,11 @@ int scandirat(int dirfd, const char *dirp,
 	return err;
 }
 #endif
+
+/* basename version that takes a const input string */
+const char *perf_basename(const char *path)
+{
+	const char *base = strrchr(path, '/');
+
+	return base ? base + 1 : path;
+}

tools/perf/util/util.h

@@ -86,6 +86,8 @@ struct perf_debuginfod {
 };
 void perf_debuginfod_setup(struct perf_debuginfod *di);
 
+const char *perf_basename(const char *path);
+
 char *filename_with_chroot(int pid, const char *filename);
 
 int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x,