Aggressively use actual function parameters in php_verror

Zend/tests/display_error_function_args.phpt

@@ -0,0 +1,28 @@
+--TEST--
+Displaying function arguments in errors
+--INI--
+display_error_function_args=On
+--FILE--
+<?php
+
+// A function that sets its own parameters in docref call, to compare
+unlink('/');
+// Something with sensitive parameters that exists in a minimal build,
+// and also doesn't set anything in the docref call
+// XXX: May be better to provide a new zend_test func?
+password_hash("test", PASSWORD_BCRYPT, array("salt" => "123456789012345678901" . chr(0)));
+
+ini_set("display_error_function_args", "Off");
+
+unlink('/');
+password_hash("test", PASSWORD_BCRYPT, array("salt" => "123456789012345678901" . chr(0)));
+
+?>
+--EXPECTF--
+Warning: unlink('/'): %s in %s on line %d
+
+Warning: password_hash(Object(SensitiveParameterValue), '2y', Array): The "salt" option has been ignored, since providing a custom salt is no longer supported in %s on line %d
+
+Warning: unlink(/): %s in %s on line %d
+
+Warning: password_hash(): The "salt" option has been ignored, since providing a custom salt is no longer supported in %s on line %d

Zend/zend_exceptions.c

@@ -542,6 +542,31 @@ static void _build_trace_args(zval *arg, smart_str *str) /* {{{ */
 }
 /* }}} */
 
+static void _build_trace_args_list(zval *tmp, smart_str *str) /* {{{ */
+{
+	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();
+
+		if (last_len != ZSTR_LEN(str->s)) {
+			ZSTR_LEN(str->s) -= 2; /* remove last ', ' */
+		}
+	} else {
+		/* only happens w/ reflection abuse (Zend/tests/bug63762.phpt) */
+		zend_error(E_WARNING, "args element is not an array");
+	}
+}
+/* }}} */
+
 static void _build_trace_string(smart_str *str, const HashTable *ht, uint32_t num) /* {{{ */
 {
 	zval *file, *tmp;
@@ -579,30 +604,49 @@ 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();
-
-			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");
-		}
+		_build_trace_args_list(tmp, str);
 	}
 	smart_str_appends(str, ")\n");
 }
 /* }}} */
 
+/* {{{ 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) {
+	zval *tmp;
+	smart_str str = {0};
+	/* init because ASan will complain */
+	smart_str_appends(&str, "");
+
+	tmp = zend_hash_find_known_hash(frame, ZSTR_KNOWN(ZEND_STR_ARGS));
+	if (tmp) {
+		_build_trace_args_list(tmp, &str);
+	}
+
+	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) {
+		dynamic_params = zend_trace_function_args_to_string(Z_ARRVAL_P(first_frame));
+	}
+	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;
 	zval *frame;

Zend/zend_exceptions.h

@@ -66,6 +66,8 @@ 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

@@ -64,6 +64,7 @@
 #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
@@ -802,6 +803,7 @@ PHP_INI_BEGIN()
 
 	STD_PHP_INI_ENTRY_EX("display_errors",		"1",		PHP_INI_ALL,		OnUpdateDisplayErrors,	display_errors,			php_core_globals,	core_globals, display_errors_mode)
 	STD_PHP_INI_BOOLEAN("display_startup_errors",	"1",	PHP_INI_ALL,		OnUpdateBool,			display_startup_errors,	php_core_globals,	core_globals)
+	STD_PHP_INI_BOOLEAN("display_error_function_args",	"0",	PHP_INI_ALL,		OnUpdateBool,			display_error_function_args,	php_core_globals,	core_globals)
 	STD_PHP_INI_BOOLEAN("enable_dl",			"1",		PHP_INI_SYSTEM,		OnUpdateBool,			enable_dl,				php_core_globals,	core_globals)
 	STD_PHP_INI_BOOLEAN("expose_php",			"1",		PHP_INI_SYSTEM,		OnUpdateBool,			expose_php,				php_core_globals,	core_globals)
 	STD_PHP_INI_ENTRY("docref_root", 			"", 		PHP_INI_ALL,		OnUpdateString,			docref_root,			php_core_globals,	core_globals)
@@ -1134,7 +1136,18 @@ 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;
+		/*
+		 * By default, this is disabled because it requires rewriting
+		 * almost all PHPT files.
+		 */
+		if (PG(display_error_function_args)) {
+			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);

main/php_globals.h

@@ -61,6 +61,7 @@ struct _php_core_globals {
 
 	uint8_t display_errors;
 	bool display_startup_errors;
+	bool display_error_function_args;
 	bool log_errors;
 	bool ignore_repeated_errors;
 	bool ignore_repeated_source;

php.ini-development

@@ -611,6 +611,15 @@ ignore_repeated_source = Off
 ; Production Value: On
 ;fatal_error_backtraces = On
 
+; This directive controls whether PHP will print the actual arguments of a
+; function upon an error. If disabled (or there was an error fetching the
+; arguments), the function providing the error may optionally provide some
+; additional information after the problem function's name.
+; Default Value: Off
+; Development Value: On
+; Production Value: On
+display_error_function_args = On
+
 ;;;;;;;;;;;;;;;;;
 ; Data Handling ;
 ;;;;;;;;;;;;;;;;;

php.ini-production

@@ -613,6 +613,15 @@ ignore_repeated_source = Off
 ; Production Value: On
 ;fatal_error_backtraces = On
 
+; This directive controls whether PHP will print the actual arguments of a
+; function upon an error. If disabled (or there was an error fetching the
+; arguments), the function providing the error may optionally provide some
+; additional information after the problem function's name.
+; Default Value: Off
+; Development Value: On
+; Production Value: On
+display_error_function_args = On
+
 ;;;;;;;;;;;;;;;;;
 ; Data Handling ;
 ;;;;;;;;;;;;;;;;;

run-tests.php

@@ -275,6 +275,7 @@ function main(): void
         'fatal_error_backtraces=Off',
         'display_errors=1',
         'display_startup_errors=1',
+        'display_error_function_args=0',
         'log_errors=0',
         'html_errors=0',
         'track_errors=0',

scripts/dev/bless_tests.php

@@ -74,6 +74,10 @@ function normalizeOutput(string $out): string {
         'Resource ID#%d used as offset, casting to integer (%d)',
         $out);
     $out = preg_replace('/string\(\d+\) "([^"]*%d)/', 'string(%d) "$1', $out);
+    // Inside of strings, replace absolute paths that have been truncated with
+    // any string. These tend to contain homedirs with usernames, not good.
+    $out = preg_replace("/'\\/.*\.\\.\\.'/", "'%s'", $out);
+    $out = preg_replace("/'file:\/\\/.*\.\\.\\.'/", "'%s'", $out);
     $out = str_replace("\0", '%0', $out);
     return $out;
 }