Add ReflectionConstant::getFileName()

Allow determining the name of the file that defined a constant, when the
constant was defined in userland code via const or define(). For constants
defined by PHP core or extensions, false is returned, matching the existing
getFileName() methods on other reflection classes.

Fixes GH-15723
Closes GH-15847

Author: DanielEScherzer

UPGRADING

@@ -88,6 +88,9 @@ PHP 8.5 UPGRADE NOTES
     statement from the DEALLOCATE sql command in that we can reuse
     its name afterwards.
 
+- Reflection:
+  . ReflectionConstant::getFileName() was introduced.
+
 ========================================
 7. New Classes and Interfaces
 ========================================

Zend/zend_constants.c

@@ -46,12 +46,18 @@ void free_zend_constant(zval *zv)
 		if (c->name) {
 			zend_string_release_ex(c->name, 0);
 		}
+		if (c->filename) {
+			zend_string_release_ex(c->filename, 0);
+		}
 		efree(c);
 	} else {
 		zval_internal_ptr_dtor(&c->value);
 		if (c->name) {
 			zend_string_release_ex(c->name, 1);
 		}
+		if (c->filename) {
+			zend_string_release_ex(c->filename, 1);
+		}
 		free(c);
 	}
 }
@@ -68,6 +74,9 @@ static void copy_zend_constant(zval *zv)
 
 	c = Z_PTR_P(zv);
 	c->name = zend_string_copy(c->name);
+	if (c->filename != NULL) {
+		c->filename = zend_string_copy(c->filename);
+	}
 	if (Z_TYPE(c->value) == IS_STRING) {
 		Z_STR(c->value) = zend_string_dup(Z_STR(c->value), 1);
 	}
@@ -495,13 +504,24 @@ ZEND_API zend_result zend_register_constant(zend_constant *c)
 		name = c->name;
 	}
 
+	zend_string *filename = zend_get_executed_filename_ex();
+	if (filename == NULL) {
+		c->filename = NULL;
+	} else {
+		c->filename = zend_string_copy(filename);
+	}
+
 	/* Check if the user is trying to define any special constant */
 	if (zend_string_equals_literal(name, "__COMPILER_HALT_OFFSET__")
 		|| (!persistent && zend_get_special_const(ZSTR_VAL(name), ZSTR_LEN(name)))
 		|| zend_hash_add_constant(EG(zend_constants), name, c) == NULL
 	) {
 		zend_error(E_WARNING, "Constant %s already defined", ZSTR_VAL(name));
 		zend_string_release(c->name);
+		if (c->filename) {
+			zend_string_release(c->filename);
+			c->filename = NULL;
+		}
 		if (!persistent) {
 			zval_ptr_dtor_nogc(&c->value);
 		}

Zend/zend_constants.h

@@ -33,6 +33,7 @@
 typedef struct _zend_constant {
 	zval value;
 	zend_string *name;
+	zend_string *filename;
 } zend_constant;
 
 #define ZEND_CONSTANT_FLAGS(c) \

Zend/zend_execute_API.c

@@ -299,6 +299,9 @@ ZEND_API void zend_shutdown_executor_values(bool fast_shutdown)
 				if (c->name) {
 					zend_string_release_ex(c->name, 0);
 				}
+				if (c->filename) {
+					zend_string_release_ex(c->filename, 0);
+				}
 				efree(c);
 				zend_string_release_ex(key, 0);
 			} ZEND_HASH_MAP_FOREACH_END_DEL();

ext/reflection/php_reflection.c

@@ -7553,6 +7553,20 @@ ZEND_METHOD(ReflectionConstant, isDeprecated)
 	RETURN_BOOL(ZEND_CONSTANT_FLAGS(const_) & CONST_DEPRECATED);
 }
 
+ZEND_METHOD(ReflectionConstant, getFileName)
+{
+	reflection_object *intern;
+	zend_constant *const_;
+
+	ZEND_PARSE_PARAMETERS_NONE();
+
+	GET_REFLECTION_OBJECT_PTR(const_);
+	if (const_->filename != NULL) {
+		RETURN_STR_COPY(const_->filename);
+	}
+	RETURN_FALSE;
+}
+
 ZEND_METHOD(ReflectionConstant, __toString)
 {
 	reflection_object *intern;

ext/reflection/php_reflection.stub.php

@@ -916,5 +916,7 @@ public function getValue(): mixed {}
 
     public function isDeprecated(): bool {}
 
+    public function getFileName(): string|false {}
+
     public function __toString(): string {}
 }

ext/reflection/php_reflection_arginfo.h

@@ -0,0 +1,44 @@
+--TEST--
+ReflectionConstant::getFileName()
+--FILE--
+<?php
+
+include "included5.inc";
+
+function testConstant(string $name): void {
+    $ref = new ReflectionConstant($name);
+    echo "$name: ";
+    var_dump($ref->getFileName());
+}
+
+define('IN_CURRENT_FILE_DEFINED', 42);
+const IN_CURRENT_FILE_AST = 123;
+
+echo "From PHP:\n";
+testConstant('PHP_VERSION');
+testConstant('STDIN');
+testConstant('STDOUT');
+testConstant('STDERR');
+
+echo "\nFrom the current file:\n";
+testConstant('IN_CURRENT_FILE_DEFINED');
+testConstant('IN_CURRENT_FILE_AST');
+
+echo "\nFrom an included file:\n";
+testConstant('INCLUDED_CONSTANT_DEFINED');
+testConstant('INCLUDED_CONSTANT_AST');
+?>
+--EXPECTF--
+From PHP:
+PHP_VERSION: bool(false)
+STDIN: bool(false)
+STDOUT: bool(false)
+STDERR: bool(false)
+
+From the current file:
+IN_CURRENT_FILE_DEFINED: string(%d) "%sReflectionConstant_getFileName.php"
+IN_CURRENT_FILE_AST: string(%d) "%sReflectionConstant_getFileName.php"
+
+From an included file:
+INCLUDED_CONSTANT_DEFINED: string(%d) "%sincluded5.inc"
+INCLUDED_CONSTANT_AST: string(%d) "%sincluded5.inc"

ext/reflection/tests/ReflectionConstant_getFileName.phpt

@@ -0,0 +1,5 @@
+<?php
+define('INCLUDED_CONSTANT_DEFINED', 'Foo');
+
+const INCLUDED_CONSTANT_AST = 'Bar';
+?>