gen_stub: Using $this when not in object context

[DanielEScherzer]

Description

In ext/zend_test/test.stub.php I added

    /** @var string */
    const TEMP_TEST = __FILE__;

and then ran
php build/gen_stub.php ext/zend_test/test.stub.php

Output:

root@228aa53d048d:/usr/src/php# php build/gen_stub.php ext/zend_test/test.stub.php

Fatal error: Uncaught Error: Using $this when not in object context in /usr/src/php/build/gen_stub.php:2173
Stack trace:
#0 /usr/src/php/build/PHP-Parser-5.3.1/lib/PhpParser/ConstExprEvaluator.php(148): EvaluatedValue::{closure}(Object(PhpParser\Node\Scalar\MagicConst\File))
#1 /usr/src/php/build/PHP-Parser-5.3.1/lib/PhpParser/ConstExprEvaluator.php(102): PhpParser\ConstExprEvaluator->evaluate(Object(PhpParser\Node\Scalar\MagicConst\File))
#2 /usr/src/php/build/gen_stub.php(2209): PhpParser\ConstExprEvaluator->evaluateDirectly(Object(PhpParser\Node\Scalar\MagicConst\File))
#3 /usr/src/php/build/gen_stub.php(2615): EvaluatedValue::createFromExpression(Object(PhpParser\Node\Scalar\MagicConst\File), Object(SimpleType), NULL, Array)
#4 /usr/src/php/build/gen_stub.php(5204): ConstInfo->getDeclaration(Array)
#5 /usr/src/php/build/gen_stub.php(125): generateArgInfoCode('test', Object(FileInfo), Array, 'e496fa1faa84677...')
#6 /usr/src/php/build/gen_stub.php(6127): processStubFile('ext/zend_test/t...', Object(Context))
#7 {main}
  thrown in /usr/src/php/build/gen_stub.php on line 2173

Cause:

php-src/build/gen_stub.php

Lines 2119 to 2125 in 6329248

	/**
	* @param array<string, ConstInfo> $allConstInfos
	*/
	public static function createFromExpression(Expr $expr, ?SimpleType $constType, ?string $cConstName, array $allConstInfos): EvaluatedValue
	{
	// This visitor replaces the PHP constants by C constants. It allows direct expansion of the compiled constants, e.g. later in the pretty printer.
	$visitor = new class($allConstInfos) extends PhpParser\NodeVisitorAbstract

... later in that same static function ...

php-src/build/gen_stub.php

Lines 2169 to 2174 in 6329248

	$evaluator = new ConstExprEvaluator(
	static function (Expr $expr) use ($allConstInfos, &$isUnknownConstValue) {
	// $expr is a ConstFetch with a name of a C macro here
	if (!$expr instanceof Expr\ConstFetch) {
	throw new Exception($this->getVariableTypeName() . " " . $this->name->__toString() . " has an unsupported value");
	}

getVariableTypeName() is only something that exists on VariableLike instances so I'm not even sure what the correct replacement should be

PHP Version

6329248

Operating System

No response

[DanielEScherzer]

CC @kocsismate - it looks like this has been an issue since 8.2

php-src/build/gen_stub.php

Lines 1588 to 1597 in e144c58

	public static function createFromExpression(Expr $expr, ?SimpleType $constType, ?string $cConstName, iterable $allConstInfos): EvaluatedValue
	{
	$originatingConst = null;
	$isUnknownConstValue = null;
	$evaluator = new ConstExprEvaluator(
	function (Expr $expr) use ($allConstInfos, &$constType, &$originatingConst, &$isUnknownConstValue) {
	if (!$expr instanceof Expr\ConstFetch && !$expr instanceof Expr\ClassConstFetch) {
	throw new Exception($this->getVariableTypeName() . " " . $this->getVariableLikeName() . " has an unsupported value");
	}

Given that the bug is in part of the build system, should it be fixed on 8.2? Just 8.3+? Just master?

[TimWolla]

Given that this hasn't been a problem so far, it's somewhat feature request-ish. I'd say master (unless an earlier branch makes merges easier).

[kocsismate]

I agree with Tim, if noone needed a fix until now then we could just fix it for master :) And thanks for finding it BTW!

getVariableTypeName() is only something that exists on VariableLike instances so I'm not even sure what the correct replacement should be

Then the exception message could be changed to avoid the problem in the first place ^^ Like only displaying the expression 🤔

[kocsismate]

I created a possible fix: #18327

It will display the following message for the example code:

In ./ext/zend_test/test.stub.php:
Expression at line 12 must be a global, non-magic constant

What do you think?

[DanielEScherzer]

Works for me