core-builtin: add and use built in shim wrapper for strrchr

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>

Author: ColinIanKing

Makefile.config

@@ -2644,6 +2644,7 @@ functions: \
 	BUILTIN_STRDUP \
 	BUILTIN_STRLEN \
 	BUILTIN_STRNCMP \
+	BUILTIN_STRRCHR \
 	BUILTIN_STRSTR \
 	BUILTIN_SUPPORTS \
 	BUILTIN_TAN \
@@ -3741,6 +3742,9 @@ BUILTIN_STRLEN:
 BUILTIN_STRNCMP:
 	$(call check,test-builtin-strncmp,HAVE_BUILTIN_STRNCMP,__builtin_strncmp)
 
+BUILTIN_STRRCHR:
+	$(call check,test-builtin-strrchr,HAVE_BUILTIN_STRRCHR,__builtin_strrchr)
+
 BUILTIN_STRSTR:
 	$(call check,test-builtin-strstr,HAVE_BUILTIN_STRSTR,__builtin_strstr)
 

core-builtin.h

@@ -85,6 +85,12 @@
 #define shim_strncmp(s1, s2, n)		strncmp((s1), (s2), (n))
 #endif
 
+#if defined(HAVE_BUILTIN_STRRCHR)
+#define shim_strrchr(str, c)		__builtin_strrchr((str), (c))
+#else
+#define shim_strrchr(str, c)		strrchr((str), (c))
+#endif
+
 #if defined(HAVE_BUILTIN_STRSTR)
 #define shim_strstr(haystack, needle)	__builtin_strstr((haystack), (needle))
 #else

core-cpu-cache.c

@@ -327,7 +327,7 @@ static int stress_cpu_cache_get_riscv(
 	int cpu_num;
 
 	/* Parse CPU number */
-	base = strrchr(cpu_path, '/');
+	base = shim_strrchr(cpu_path, '/');
 	if (!base)
 		return 0;
 	base++;

stress-gpu.c

@@ -18,6 +18,7 @@
  *
  */
 #include "stress-ng.h"
+#include "core-builtin.h"
 #include "core-out-of-memory.h"
 #include "core-pthread.h"
 #include "core-signal.h"
@@ -108,7 +109,7 @@ static void stress_get_gpu_freq_mhz(double *gpu_freq)
 
 static void stress_gpu_trim_newline(char *str)
 {
-	char *ptr = strrchr(str, '\n');
+	char *ptr = shim_strrchr(str, '\n');
 
 	if (ptr)
 		*ptr = '\0';

stress-inode-flags.c

@@ -208,7 +208,7 @@ static int stress_inode_flags_stressor(
 #endif
 
 	/* Find basename */
-	file_name = strrchr(data->file_name, '/');
+	file_name = shim_strrchr(data->file_name, '/');
 	if (file_name)
 		file_name++;
 

test/test-builtin-strrchr.c

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2026      Colin Ian King
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+#include <string.h>
+
+int main(int argc, char **argv)
+{
+	static char str[] = "test";
+
+	return  (int)(__builtin_strrchr(str, 's') - str);
+}
+