Aggressively use actual func params in verror

PHP errors used to not show parameter info consistently.
Make it so that it uses a backtrace to get function info, similar to how
exceptions work.

This makes the docref error functions' parameter argument mostly
vestigal, being used only if allocation fails basically.

Several tests will fail from the fact we include function params.
One annoyance is that _build_trace_args truncates strings according to
exception_string_param_max_len.

See GH-12048

Co-authored-by: Tim Düsterhus <tim@bastelstu.be>

Author: NattyNarwhal

Zend/zend_exceptions.c

@@ -506,7 +506,7 @@ ZEND_METHOD(ErrorException, getSeverity)
 		} \
 	} while (0)
 
-static void _build_trace_args(zval *arg, smart_str *str) /* {{{ */
+static void build_trace_args(zval *arg, smart_str *str) /* {{{ */
 {
 	/* the trivial way would be to do
 	 * convert_to_string(arg);
@@ -516,24 +516,21 @@ static void _build_trace_args(zval *arg, smart_str *str) /* {{{ */
 
 	ZVAL_DEREF(arg);
 
-	if (smart_str_append_zval(str, arg, EG(exception_string_param_max_len)) == SUCCESS) {
-		smart_str_appends(str, ", ");
-	} else {
+	if (smart_str_append_zval(str, arg, EG(exception_string_param_max_len)) != SUCCESS) {
 		switch (Z_TYPE_P(arg)) {
 			case IS_RESOURCE:
 				smart_str_appends(str, "Resource id #");
 				smart_str_append_long(str, Z_RES_HANDLE_P(arg));
-				smart_str_appends(str, ", ");
 				break;
 			case IS_ARRAY:
-				smart_str_appends(str, "Array, ");
+				smart_str_appends(str, "Array");
 				break;
 			case IS_OBJECT: {
 				zend_string *class_name = Z_OBJ_HANDLER_P(arg, get_class_name)(Z_OBJ_P(arg));
 				smart_str_appends(str, "Object(");
 				/* cut off on NULL byte ... class@anonymous */
 				smart_str_appends(str, ZSTR_VAL(class_name));
-				smart_str_appends(str, "), ");
+				smart_str_appends(str, ")");
 				zend_string_release_ex(class_name, 0);
 				break;
 			}
@@ -542,7 +539,30 @@ static void _build_trace_args(zval *arg, smart_str *str) /* {{{ */
 }
 /* }}} */
 
-static void _build_trace_string(smart_str *str, const HashTable *ht, uint32_t num) /* {{{ */
+static void build_trace_args_list(zval *tmp, smart_str *str) /* {{{ */
+{
+	if (UNEXPECTED(Z_TYPE_P(tmp) != IS_ARRAY)) {
+		/* only happens w/ reflection abuse (Zend/tests/bug63762.phpt) */
+		zend_error(E_WARNING, "args element is not an array");
+		return;
+	}
+
+	bool first = true;
+	ZEND_HASH_FOREACH_STR_KEY_VAL(Z_ARRVAL_P(tmp), zend_string *name, zval *arg) {
+		if (!first) {
+			smart_str_appends(str, ", ");
+		}
+		first = false;
+		if (name) {
+			smart_str_append(str, name);
+			smart_str_appends(str, ": ");
+		}
+		build_trace_args(arg, str);
+	} ZEND_HASH_FOREACH_END();
+}
+/* }}} */
+
+static void build_trace_string(smart_str *str, const HashTable *ht, uint32_t num) /* {{{ */
 {
 	zval *file, *tmp;
 
@@ -588,27 +608,40 @@ static void _build_trace_string(smart_str *str, const HashTable *ht, uint32_t nu
 	smart_str_appendc(str, '(');
 	tmp = zend_hash_find_known_hash(ht, ZSTR_KNOWN(ZEND_STR_ARGS));
 	if (tmp) {
-		if (EXPECTED(Z_TYPE_P(tmp) == IS_ARRAY)) {
-			size_t last_len = ZSTR_LEN(str->s);
-			zend_string *name;
-			zval *arg;
-
-			ZEND_HASH_FOREACH_STR_KEY_VAL(Z_ARRVAL_P(tmp), name, arg) {
-				if (name) {
-					smart_str_append(str, name);
-					smart_str_appends(str, ": ");
-				}
-				_build_trace_args(arg, str);
-			} ZEND_HASH_FOREACH_END();
+		build_trace_args_list(tmp, str);
+	}
+	smart_str_appends(str, ")\n");
+}
+/* }}} */
 
-			if (last_len != ZSTR_LEN(str->s)) {
-				ZSTR_LEN(str->s) -= 2; /* remove last ', ' */
-			}
-		} else {
-			zend_error(E_WARNING, "args element is not an array");
+/* {{{ Gets the function arguments printed as a string from a backtrace frame. */
+ZEND_API zend_string *zend_trace_function_args_to_string(const HashTable *frame) {
+	smart_str str = {0};
+
+	zval *tmp = zend_hash_find_known_hash(frame, ZSTR_KNOWN(ZEND_STR_ARGS));
+	if (tmp) {
+		build_trace_args_list(tmp, &str);
+	}
+
+	return smart_str_extract(&str);
+}
+/* }}} */
+
+/* {{{ 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;
+	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) {
+		zval *first_frame = zend_hash_index_find(Z_ARRVAL(backtrace), 0);
+		if (first_frame) {
+			dynamic_params = zend_trace_function_args_to_string(Z_ARRVAL_P(first_frame));
 		}
 	}
-	smart_str_appends(str, ")\n");
+	zval_ptr_dtor(&backtrace);
+	return dynamic_params;
 }
 /* }}} */
 
@@ -624,7 +657,7 @@ ZEND_API zend_string *zend_trace_to_string(const HashTable *trace, bool include_
 			continue;
 		}
 
-		_build_trace_string(&str, Z_ARRVAL_P(frame), num++);
+		build_trace_string(&str, Z_ARRVAL_P(frame), num++);
 	} ZEND_HASH_FOREACH_END();
 
 	if (include_main) {

Zend/zend_exceptions.h

@@ -65,6 +65,8 @@ ZEND_API zend_result zend_update_exception_properties(zend_execute_data *execute
 /* show an exception using zend_error(severity,...), severity should be E_ERROR */
 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(const 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

@@ -62,6 +62,7 @@
 #include "win32/php_registry.h"
 #include "ext/standard/flock_compat.h"
 #endif
+#include "Zend/zend_builtin_functions.h"
 #include "Zend/zend_exceptions.h"
 
 #if PHP_SIGCHILD
@@ -1132,7 +1133,12 @@ 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) {
-		origin_len = spprintf(&origin, 0, "%s%s%s(%s)", class_name, space, function, params);
+		zend_string *dynamic_params = NULL;
+		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);
+		}
 	} else {
 		origin_len = strlen(function);
 		origin = estrndup(function, origin_len);