Make it possible to break error hook processing

Error hooks should normally return SUCCESS but they can return FAILURE
in order to stop the processing of the current hook list as it is the
case for the bailout one.

It also has the benefit of standardizing the API for error hooks.

Author: Patrick Allaert

Zend/zend_errors.c

@@ -26,7 +26,7 @@
 #include "ext/standard/html.h"
 
 /* {{{ zend_error_display_cb */
-ZEND_API void zend_error_display_cb(ZEND_ERROR_CB_HOOK_ARGS)
+ZEND_ERROR_CB_API zend_error_display_cb(ZEND_ERROR_CB_HOOK_ARGS)
 {
 	char *buffer = PG(last_error_message);
 
@@ -80,11 +80,12 @@ ZEND_API void zend_error_display_cb(ZEND_ERROR_CB_HOOK_ARGS)
 		zend_output_debug_string(trigger_break, "%s(%d) : %s - %s", error_filename, error_lineno, error_type_str, buffer);
 	}
 #endif
+	return SUCCESS;
 }
 /* }}} */
 
 /* {{{ zend_error_log_cb */
-ZEND_API void zend_error_log_cb(ZEND_ERROR_CB_HOOK_ARGS)
+ZEND_ERROR_CB_API zend_error_log_cb(ZEND_ERROR_CB_HOOK_ARGS)
 {
 	char *buffer = PG(last_error_message);
 
@@ -99,11 +100,12 @@ ZEND_API void zend_error_log_cb(ZEND_ERROR_CB_HOOK_ARGS)
 		php_log_err(log_buffer);
 		efree(log_buffer);
 	}
+	return SUCCESS;
 }
 /* }}} */
 
 /* {{{ zend_error_bailout_cb */
-ZEND_API zend_bool zend_error_bailout_cb(ZEND_ERROR_CB_HOOK_ARGS)
+ZEND_ERROR_CB_API zend_error_bailout_cb(ZEND_ERROR_CB_HOOK_ARGS)
 {
 	/* Bail out if we can't recover */
 	switch (type) {
@@ -138,11 +140,11 @@ ZEND_API zend_bool zend_error_bailout_cb(ZEND_ERROR_CB_HOOK_ARGS)
 					zend_set_memory_limit(PG(memory_limit));
 					zend_objects_store_mark_destructed(&EG(objects_store));
 					zend_bailout();
-					return 1;
+					return FAILURE;
 				}
 			}
 	}
-	return 0;
+	return SUCCESS;
 }
 /* }}} */
 

Zend/zend_errors.h

@@ -56,11 +56,12 @@ typedef enum {
 #define ZEND_ERROR_CB_FUNC_ARGS_PASSTHRU type, error_filename, error_lineno, format, args
 #define ZEND_ERROR_CB_HOOK_ARGS ZEND_ERROR_CB_FUNC_ARGS, const char *error_type_str
 #define ZEND_ERROR_CB_HOOK_ARGS_PASSTHRU ZEND_ERROR_CB_FUNC_ARGS_PASSTHRU, error_type_str
+#define ZEND_ERROR_CB_API ZEND_API int
 
 BEGIN_EXTERN_C()
-ZEND_API void zend_error_display_cb(ZEND_ERROR_CB_HOOK_ARGS);
-ZEND_API void zend_error_log_cb(ZEND_ERROR_CB_HOOK_ARGS);
-ZEND_API zend_bool zend_error_bailout_cb(ZEND_ERROR_CB_HOOK_ARGS);
+ZEND_ERROR_CB_API zend_error_display_cb(ZEND_ERROR_CB_HOOK_ARGS);
+ZEND_ERROR_CB_API zend_error_log_cb(ZEND_ERROR_CB_HOOK_ARGS);
+ZEND_ERROR_CB_API zend_error_bailout_cb(ZEND_ERROR_CB_HOOK_ARGS);
 ZEND_API void zend_append_error_hook(zend_error_cb_hook_t hook_part, void (*hook)(ZEND_ERROR_CB_HOOK_ARGS));
 ZEND_API void zend_prepend_error_hook(zend_error_cb_hook_t hook_part, void (*hook)(ZEND_ERROR_CB_HOOK_ARGS));
 ZEND_API void zend_clear_error_hook(zend_error_cb_hook_t hook_part);

main/main.c

@@ -961,11 +961,12 @@ PHPAPI void php_html_puts(const char *str, size_t size)
 /* }}} */
 
 #define CALL_ERROR_HOOKS(HOOK_LIST) for ( \
-			hook = (void (**)(ZEND_ERROR_CB_HOOK_ARGS)) zend_llist_get_first_ex(&(PG(error_hooks)[HOOK_LIST]), &pos); \
-            hook != NULL; \
+			hook_result = SUCCESS, \
+			hook = (int (**)(ZEND_ERROR_CB_HOOK_ARGS)) zend_llist_get_first_ex(&(PG(error_hooks)[HOOK_LIST]), &pos); \
+            hook != NULL && hook_result == SUCCESS; \
             hook = zend_llist_get_next_ex(&(PG(error_hooks)[HOOK_LIST]), &pos)) { \
 			va_copy(copy, args); \
-			(*hook)(type, error_filename, error_lineno, format, copy, error_type_str); \
+			hook_result = (*hook)(type, error_filename, error_lineno, format, copy, error_type_str); \
 			va_end(copy); \
 		}
 
@@ -976,10 +977,9 @@ static void php_error_cb(PHP_ERROR_CB_FUNC_ARGS)
 	char *buffer, *error_type_str;
 	int buffer_len, display;
 	zend_llist_position pos;
-	void (**hook)(ZEND_ERROR_CB_HOOK_ARGS);
-	zend_bool (**bailout_hook)(ZEND_ERROR_CB_HOOK_ARGS);
+	int (**hook)(ZEND_ERROR_CB_HOOK_ARGS);
 	va_list copy;
-	zend_bool bailout = 0;
+	int hook_result;
 
 	buffer_len = (int)vspprintf(&buffer, PG(log_errors_max_len), format, args);
 
@@ -1097,19 +1097,10 @@ static void php_error_cb(PHP_ERROR_CB_FUNC_ARGS)
 		CALL_ERROR_HOOKS(E_HOOK_PROCESS);
 	}
 
-	for (
-			bailout_hook = (zend_bool (**)(ZEND_ERROR_CB_HOOK_ARGS)) zend_llist_get_first_ex(&(PG(error_hooks)[E_HOOK_BAILOUT]), &pos);
-            bailout_hook != NULL;
-            bailout_hook = zend_llist_get_next_ex(&(PG(error_hooks)[E_HOOK_BAILOUT]), &pos)) {
-			va_copy(copy, args);
-			bailout = (*bailout_hook)(type, error_filename, error_lineno, format, copy, error_type_str);
-			va_end(copy);
-			if (bailout) {
-				goto error_cb_end;
-			}
-	}
+	CALL_ERROR_HOOKS(E_HOOK_BAILOUT);
 
-	if (!display) {
+	// hook_result == FAILURE means we must bail out
+	if (hook_result == FAILURE || !display) {
 		goto error_cb_end;
 	}