Backport fix for GH-17687

Introducing a new attribute macro in lower branches is an ABI break and
not allowed. However, we still need to fix the warnings such that
-Werror builds don't break. So we copy the macro from the master branch
to the C files in the appropriate places.

ext/fileinfo/data_file.c

@@ -1,6 +1,6 @@
 /* This is a generated file, do not modify */
 /* Usage: php create_data_file.php /path/to/magic.mgc > data_file.c */
-const unsigned char php_magic_database[7955032] = {
+const unsigned char php_magic_database[7955032] ZEND_NONSTRING = {
 0x1C, 0x04, 0x1E, 0xF1, 0x12, 0x00, 0x00, 0x00, 0xD2, 0x3B, 0x00, 0x00, 0xD2, 0x16, 0x00, 0x00, 
 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 

ext/fileinfo/libmagic/apprentice.c

@@ -185,6 +185,12 @@ private struct {
 	{ NULL, 0, NULL }
 };
 
+#if __has_attribute(nonstring)
+# define ZEND_NONSTRING __attribute__((nonstring))
+#else
+# define ZEND_NONSTRING
+#endif
+
 #include "../data_file.c"
 
 #ifdef COMPILE_ONLY

ext/pdo/pdo_sqlstate.c

@@ -24,8 +24,14 @@
 #include "php_pdo.h"
 #include "php_pdo_driver.h"
 
+#if __has_attribute(nonstring)
+# define ZEND_NONSTRING __attribute__((nonstring))
+#else
+# define ZEND_NONSTRING
+#endif
+
 struct pdo_sqlstate_info {
-	const char state[5];
+	const char state[5] ZEND_NONSTRING;
 	const char *desc;
 };
 

ext/standard/crypt_sha256.c

@@ -317,8 +317,14 @@ static const char sha256_rounds_prefix[] = "rounds=";
 /* Maximum number of rounds.  */
 #define ROUNDS_MAX 999999999
 
+#if __has_attribute(nonstring)
+# define ZEND_NONSTRING __attribute__((nonstring))
+#else
+# define ZEND_NONSTRING
+#endif
+
 /* Table with characters for base64 transformation.  */
-static const char b64t[64] =
+static const char b64t[64] ZEND_NONSTRING =
 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
 
 char * php_sha256_crypt_r(const char *key, const char *salt, char *buffer, int buflen)

ext/standard/crypt_sha512.c

@@ -350,8 +350,14 @@ static const char sha512_rounds_prefix[] = "rounds=";
 /* Maximum number of rounds.  */
 #define ROUNDS_MAX 999999999
 
+#if __has_attribute(nonstring)
+# define ZEND_NONSTRING __attribute__((nonstring))
+#else
+# define ZEND_NONSTRING
+#endif
+
 /* Table with characters for base64 transformation.  */
-static const char b64t[64] =
+static const char b64t[64] ZEND_NONSTRING =
 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";