Add preg_last_error_msg() function

Provides the last PCRE error as a human-readable message, similar
to functionality existing in other extensions, such as
json_last_error_msg().

Closes GH-5185.

1 files changed, 38 insertions, 11 deletions

diff --git a/ext/pcre/php_pcre.c b/ext/pcre/php_pcre.c
index edf48ca1f4..fdc1b1b856 100644
--- a/ext/pcre/php_pcre.c
+++ b/ext/pcre/php_pcre.c
@@ -52,17 +52,6 @@ struct _pcre_cache_entry {
 	uint32_t refcount;
 };
 
-enum {
-	PHP_PCRE_NO_ERROR = 0,
-	PHP_PCRE_INTERNAL_ERROR,
-	PHP_PCRE_BACKTRACK_LIMIT_ERROR,
-	PHP_PCRE_RECURSION_LIMIT_ERROR,
-	PHP_PCRE_BAD_UTF8_ERROR,
-	PHP_PCRE_BAD_UTF8_OFFSET_ERROR,
-	PHP_PCRE_JIT_STACKLIMIT_ERROR
-};
-
-
 PHPAPI ZEND_DECLARE_MODULE_GLOBALS(pcre)
 
 #ifdef HAVE_PCRE_JIT_SUPPORT
@@ -138,6 +127,33 @@ static void pcre_handle_exec_error(int pcre_code) /* {{{ */
 }
 /* }}} */
 
+static const char *php_pcre_get_error_msg(php_pcre_error_code error_code) /* {{{ */
+{
+    switch (error_code) {
+        case PHP_PCRE_NO_ERROR:
+            return "No error";
+        case PHP_PCRE_INTERNAL_ERROR:
+            return "Internal error";
+        case PHP_PCRE_BAD_UTF8_ERROR:
+            return "Malformed UTF-8 characters, possibly incorrectly encoded";
+        case PHP_PCRE_BAD_UTF8_OFFSET_ERROR:
+            return "The offset did not correspond to the beginning of a valid UTF-8 code point";
+        case PHP_PCRE_BACKTRACK_LIMIT_ERROR:
+            return "Backtrack limit exhausted";
+        case PHP_PCRE_RECURSION_LIMIT_ERROR:
+            return "Recursion limit exhausted";
+
+#ifdef HAVE_PCRE_JIT_SUPPORT
+        case PHP_PCRE_JIT_STACKLIMIT_ERROR:
+            return "JIT stack limit exhausted";
+#endif
+
+        default:
+            return "Unknown error";
+    }
+}
+/* }}} */
+
 static void php_free_pcre_cache(zval *data) /* {{{ */
 {
 	pcre_cache_entry *pce = (pcre_cache_entry *) Z_PTR_P(data);
@@ -2957,6 +2973,16 @@ static PHP_FUNCTION(preg_last_error)
 }
 /* }}} */
 
+/* {{{ proto string preg_last_error_msg()
+   Returns the error message of the last regexp execution. */
+static PHP_FUNCTION(preg_last_error_msg)
+{
+    ZEND_PARSE_PARAMETERS_NONE();
+
+    RETURN_STRING(php_pcre_get_error_msg(PCRE_G(error_code)));
+}
+/* }}} */
+
 /* {{{ module definition structures */
 
 static const zend_function_entry pcre_functions[] = {
@@ -2970,6 +2996,7 @@ static const zend_function_entry pcre_functions[] = {
 	PHP_FE(preg_quote,					arginfo_preg_quote)
 	PHP_FE(preg_grep,					arginfo_preg_grep)
 	PHP_FE(preg_last_error,				arginfo_preg_last_error)
+	PHP_FE(preg_last_error_msg,			arginfo_preg_last_error_msg)
 	PHP_FE_END
 };