Make suggested refactors

- move build_dynamic_parameters to zend_exceptions, avoid the dependency
  on the BIF header in main.c
- (though i'm not sure if exceptions is best place for this function)
- add documentation comments to new API surface from this PR

Author: NattyNarwhal

Zend/zend_exceptions.c

@@ -620,6 +620,7 @@ static void _build_trace_string(smart_str *str, const HashTable *ht, uint32_t nu
 }
 /* }}} */
 
+/* {{{ Gets the function arguments printed as a string from a backtrace frame. */
 ZEND_API zend_string *zend_trace_function_args_to_string(HashTable *frame) {
 	zval *tmp;
 	smart_str str = {0};
@@ -634,6 +635,29 @@ ZEND_API zend_string *zend_trace_function_args_to_string(HashTable *frame) {
 	smart_str_0(&str);
 	return str.s ? str.s : ZSTR_EMPTY_ALLOC();
 }
+/* }}} */
+
+/* {{{ Gets the currently executing function's arguments as a string. Used by php_verror. */
+ZEND_API zend_string *zend_trace_current_function_args_string(void) {
+	zend_string *dynamic_params = NULL;
+	/* get a backtrace to snarf function args */
+	zval backtrace, *first_frame;
+	zend_fetch_debug_backtrace(&backtrace, /* skip_last */ 0, /* options */ 0, /* limit */ 1);
+	/* can fail esp if low memory condition */
+	if (Z_TYPE(backtrace) != IS_ARRAY) {
+		return NULL; /* don't need to free */
+	}
+	first_frame = zend_hash_index_find(Z_ARRVAL(backtrace), 0);
+	if (!first_frame) {
+		goto free_backtrace;
+	}
+	dynamic_params = zend_trace_function_args_to_string(Z_ARRVAL_P(first_frame));
+free_backtrace:
+	zval_ptr_dtor(&backtrace);
+	/* free the string after we use it */
+	return dynamic_params;
+}
+/* }}} */
 
 ZEND_API zend_string *zend_trace_to_string(const HashTable *trace, bool include_main) {
 	zend_ulong index;

Zend/zend_exceptions.h

@@ -67,6 +67,7 @@ ZEND_API zend_result zend_update_exception_properties(zend_execute_data *execute
 ZEND_API ZEND_COLD zend_result zend_exception_error(zend_object *exception, int severity);
 ZEND_NORETURN void zend_exception_uncaught_error(const char *prefix, ...) ZEND_ATTRIBUTE_FORMAT(printf, 1, 2);
 ZEND_API zend_string *zend_trace_function_args_to_string(HashTable *frame);
+ZEND_API zend_string *zend_trace_current_function_args_string(void);
 ZEND_API zend_string *zend_trace_to_string(const HashTable *trace, bool include_main);
 
 ZEND_API ZEND_COLD zend_object *zend_create_unwind_exit(void);

main/main.c

@@ -1053,26 +1053,6 @@ static zend_string *escape_html(const char *buffer, size_t buffer_len) {
 	return result;
 }
 
-static zend_string *build_dynamic_parameters(void) {
-	zend_string *dynamic_params = NULL;
-	/* get a backtrace to snarf function args */
-	zval backtrace, *first_frame;
-	zend_fetch_debug_backtrace(&backtrace, /* skip_last */ 0, /* options */ 0, /* limit */ 1);
-	/* can fail esp if low memory condition */
-	if (Z_TYPE(backtrace) != IS_ARRAY) {
-		return NULL; /* don't need to free */
-	}
-	first_frame = zend_hash_index_find(Z_ARRVAL(backtrace), 0);
-	if (!first_frame) {
-		goto free_backtrace;
-	}
-	dynamic_params = zend_trace_function_args_to_string(Z_ARRVAL_P(first_frame));
-free_backtrace:
-	zval_ptr_dtor(&backtrace);
-	/* free the string after we use it */
-	return dynamic_params;
-}
-
 /* {{{ php_verror */
 /* php_verror is called from php_error_docref<n> functions.
  * Its purpose is to unify error messages and automatically generate clickable
@@ -1156,7 +1136,7 @@ PHPAPI ZEND_COLD void php_verror(const char *docref, const char *params, int typ
 	/* if we still have memory then format the origin */
 	if (is_function) {
 		zend_string *dynamic_params = NULL;
-		dynamic_params = build_dynamic_parameters();
+		dynamic_params = zend_trace_current_function_args_string();
 		origin_len = spprintf(&origin, 0, "%s%s%s(%s)", class_name, space, function, dynamic_params ? ZSTR_VAL(dynamic_params) : params);
 		if (dynamic_params) {
 			zend_string_release(dynamic_params);