Check if the calling function is builtin, not the callback

phpstan-bot · claude · phpstan-bot · commit 627c741bb28c · 2026-03-29T10:37:21.000Z
The non-error on `uasort($options, 'strnatcasecmp')` in strict mode is
because uasort (the caller) is builtin, not because strnatcasecmp (the
callback) is builtin. Per PHP internals, when a builtin function calls
a callback, it always uses strict_types=0.

- Remove isBuiltin() from CallableParametersAcceptor interface and all
  implementations (was checking the wrong function)
- Forward $strictTypes through CallableType/ClosureType accepts() to
  CallableTypeHelper
- In FunctionCallParametersCheck, set strictTypes=false for callable
  parameters of builtin functions
- Update tests: customUsort (user-defined) in strict mode now correctly
  reports an error, while uasort/usort (builtin) do not

Co-Authored-By: Claude Opus 4.6 &lt;noreply@anthropic.com&gt;
diff --git a/src/Reflection/Callables/CallableParametersAcceptor.php b/src/Reflection/Callables/CallableParametersAcceptor.php
@@ -60,6 +60,4 @@ public function mustUseReturnValue(): TrinaryLogic;
 
 	public function getAsserts(): Assertions;
 
-	public function isBuiltin(): TrinaryLogic;
-
 }
diff --git a/src/Reflection/Callables/FunctionCallableVariant.php b/src/Reflection/Callables/FunctionCallableVariant.php
@@ -179,14 +179,4 @@ public function getAsserts(): Assertions
 		return $this->function->getAsserts();
 	}
 
-	public function isBuiltin(): TrinaryLogic
-	{
-		$isBuiltin = $this->function->isBuiltin();
-		if ($isBuiltin instanceof TrinaryLogic) {
-			return $isBuiltin;
-		}
-
-		return TrinaryLogic::createFromBoolean($isBuiltin);
-	}
-
 }
diff --git a/src/Reflection/ExtendedCallableFunctionVariant.php b/src/Reflection/ExtendedCallableFunctionVariant.php
@@ -37,7 +37,6 @@ public function __construct(
 		private array $usedVariables,
 		private TrinaryLogic $acceptsNamedArguments,
 		private TrinaryLogic $mustUseReturnValue,
-		private TrinaryLogic $isBuiltinCallable,
 		private ?Assertions $assertions = null,
 	)
 	{
@@ -93,9 +92,4 @@ public function getAsserts(): Assertions
 		return $this->assertions ?? Assertions::createEmpty();
 	}
 
-	public function isBuiltin(): TrinaryLogic
-	{
-		return $this->isBuiltinCallable;
-	}
-
 }
diff --git a/src/Reflection/GenericParametersAcceptorResolver.php b/src/Reflection/GenericParametersAcceptorResolver.php
@@ -130,7 +130,6 @@ public static function resolve(array $argTypes, ParametersAcceptor $parametersAc
 				$originalParametersAcceptor->getUsedVariables(),
 				$originalParametersAcceptor->acceptsNamedArguments(),
 				$originalParametersAcceptor->mustUseReturnValue(),
-				$originalParametersAcceptor->isBuiltin(),
 				$originalParametersAcceptor->getAsserts(),
 			);
 		}
diff --git a/src/Reflection/InaccessibleMethod.php b/src/Reflection/InaccessibleMethod.php
@@ -98,9 +98,4 @@ public function getAsserts(): Assertions
 		return Assertions::createEmpty();
 	}
 
-	public function isBuiltin(): TrinaryLogic
-	{
-		return TrinaryLogic::createMaybe();
-	}
-
 }
diff --git a/src/Reflection/ParametersAcceptorSelector.php b/src/Reflection/ParametersAcceptorSelector.php
@@ -736,7 +736,6 @@ public static function combineAcceptors(array $acceptors): ExtendedParametersAcc
 		$usedVariables = [];
 		$acceptsNamedArguments = TrinaryLogic::createNo();
 		$mustUseReturnValue = TrinaryLogic::createMaybe();
-		$isBuiltin = TrinaryLogic::createMaybe();
 
 		foreach ($acceptors as $acceptor) {
 			$returnTypes[] = $acceptor->getReturnType();
@@ -754,7 +753,6 @@ public static function combineAcceptors(array $acceptors): ExtendedParametersAcc
 				$usedVariables = array_merge($usedVariables, $acceptor->getUsedVariables());
 				$acceptsNamedArguments = $acceptsNamedArguments->or($acceptor->acceptsNamedArguments());
 				$mustUseReturnValue = $mustUseReturnValue->or($acceptor->mustUseReturnValue());
-				$isBuiltin = $isBuiltin->or($acceptor->isBuiltin());
 			}
 			$isVariadic = $isVariadic || $acceptor->isVariadic();
 
@@ -862,7 +860,6 @@ public static function combineAcceptors(array $acceptors): ExtendedParametersAcc
 				$usedVariables,
 				$acceptsNamedArguments,
 				$mustUseReturnValue,
-				$isBuiltin,
 			);
 		}
 
@@ -900,7 +897,6 @@ private static function wrapAcceptor(ParametersAcceptor $acceptor): ExtendedPara
 				$acceptor->getUsedVariables(),
 				$acceptor->acceptsNamedArguments(),
 				$acceptor->mustUseReturnValue(),
-				$acceptor->isBuiltin(),
 				$acceptor->getAsserts(),
 			);
 		}
diff --git a/src/Reflection/ResolvedFunctionVariantWithCallable.php b/src/Reflection/ResolvedFunctionVariantWithCallable.php
@@ -29,7 +29,6 @@ public function __construct(
 		private array $usedVariables,
 		private TrinaryLogic $acceptsNamedArguments,
 		private TrinaryLogic $mustUseReturnValue,
-		private TrinaryLogic $isBuiltinCallable,
 		private ?Assertions $assertions = null,
 	)
 	{
@@ -125,9 +124,4 @@ public function getAsserts(): Assertions
 		return $this->assertions ?? Assertions::createEmpty();
 	}
 
-	public function isBuiltin(): TrinaryLogic
-	{
-		return $this->isBuiltinCallable;
-	}
-
 }
diff --git a/src/Reflection/TrivialParametersAcceptor.php b/src/Reflection/TrivialParametersAcceptor.php
@@ -108,9 +108,4 @@ public function getAsserts(): Assertions
 		return Assertions::createEmpty();
 	}
 
-	public function isBuiltin(): TrinaryLogic
-	{
-		return TrinaryLogic::createMaybe();
-	}
-
 }
diff --git a/src/Rules/FunctionCallParametersCheck.php b/src/Rules/FunctionCallParametersCheck.php
@@ -363,7 +363,11 @@ public function check(
 					!$parameter->passedByReference()->createsNewVariable()
 					|| (!$isBuiltin && !$argumentValueType instanceof ErrorType)
 				) {
-					$accepts = $this->ruleLevelHelper->accepts($parameterType, $argumentValueType, $scope->isDeclareStrictTypes());
+					$callableStrictTypes = $scope->isDeclareStrictTypes();
+					if ($isBuiltin && $parameterType->isCallable()->yes()) {
+						$callableStrictTypes = false;
+					}
+					$accepts = $this->ruleLevelHelper->accepts($parameterType, $argumentValueType, $callableStrictTypes);
 
 					if (!$accepts->result) {
 						$verbosityLevel = VerbosityLevel::getRecommendedLevelByType($parameterType, $argumentValueType);
diff --git a/src/Type/CallableType.php b/src/Type/CallableType.php
@@ -139,7 +139,7 @@ public function accepts(Type $type, bool $strictTypes): AcceptsResult
 			return $type->isAcceptedBy($this, $strictTypes);
 		}
 
-		return $this->isSuperTypeOfInternal($type, true)->toAcceptsResult();
+		return $this->isSuperTypeOfInternal($type, true, $strictTypes)->toAcceptsResult();
 	}
 
 	public function isSuperTypeOf(Type $type): IsSuperTypeOfResult
@@ -151,7 +151,7 @@ public function isSuperTypeOf(Type $type): IsSuperTypeOfResult
 		return $this->isSuperTypeOfInternal($type, false);
 	}
 
-	private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny): IsSuperTypeOfResult
+	private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny, bool $strictTypes = true): IsSuperTypeOfResult
 	{
 		$isCallable = new IsSuperTypeOfResult($type->isCallable(), []);
 		if ($isCallable->no()) {
@@ -180,12 +180,11 @@ private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny): IsSup
 
 		$variantsResult = null;
 		foreach ($type->getCallableParametersAcceptors($scope) as $variant) {
-			$isBuiltinCallable = $variant->isBuiltin()->yes();
 			$variant = ParametersAcceptorSelector::selectFromTypes($parameterTypes, [$variant], false);
 			if (!$variant instanceof CallableParametersAcceptor) {
 				return IsSuperTypeOfResult::createNo([]);
 			}
-			$isSuperType = CallableTypeHelper::isParametersAcceptorSuperTypeOf($this, $variant, $treatMixedAsAny, !$isBuiltinCallable);
+			$isSuperType = CallableTypeHelper::isParametersAcceptorSuperTypeOf($this, $variant, $treatMixedAsAny, $strictTypes);
 			if ($variantsResult === null) {
 				$variantsResult = $isSuperType;
 			} else {
@@ -405,11 +404,6 @@ public function getAsserts(): Assertions
 		return Assertions::createEmpty();
 	}
 
-	public function isBuiltin(): TrinaryLogic
-	{
-		return TrinaryLogic::createMaybe();
-	}
-
 	public function toNumber(): Type
 	{
 		return new ErrorType();
diff --git a/src/Type/ClosureType.php b/src/Type/ClosureType.php
@@ -138,11 +138,6 @@ public function getAsserts(): Assertions
 		return $this->assertions;
 	}
 
-	public function isBuiltin(): TrinaryLogic
-	{
-		return TrinaryLogic::createMaybe();
-	}
-
 	/**
 	 * @return array<non-empty-string, TemplateTag>
 	 */
@@ -230,7 +225,7 @@ public function accepts(Type $type, bool $strictTypes): AcceptsResult
 			return $this->objectType->accepts($type, $strictTypes);
 		}
 
-		return $this->isSuperTypeOfInternal($type, true)->toAcceptsResult();
+		return $this->isSuperTypeOfInternal($type, true, $strictTypes)->toAcceptsResult();
 	}
 
 	public function isSuperTypeOf(Type $type): IsSuperTypeOfResult
@@ -242,7 +237,7 @@ public function isSuperTypeOf(Type $type): IsSuperTypeOfResult
 		return $this->isSuperTypeOfInternal($type, false);
 	}
 
-	private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny): IsSuperTypeOfResult
+	private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny, bool $strictTypes = true): IsSuperTypeOfResult
 	{
 		if ($type instanceof self) {
 			$parameterTypes = array_map(static fn ($parameter) => $parameter->getType(), $this->getParameters());
@@ -254,6 +249,7 @@ private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny): IsSup
 				$this,
 				$variant,
 				$treatMixedAsAny,
+				$strictTypes,
 			);
 		}
 
diff --git a/tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php b/tests/PHPStan/Rules/Functions/CallToFunctionParametersRuleTest.php
@@ -2750,7 +2750,20 @@ public function testBug11619(): void
 	#[RequiresPhp('>= 8.1')]
 	public function testBug11619Strict(): void
 	{
-		$this->analyse([__DIR__ . '/data/bug-11619-strict.php'], []);
+		$this->analyse([__DIR__ . '/data/bug-11619-strict.php'], [
+			[
+				'Parameter #1 $string1 of function strnatcasecmp expects string, Bug11619Strict\Foo given.',
+				31,
+			],
+			[
+				'Parameter #2 $string2 of function strnatcasecmp expects string, Bug11619Strict\Foo given.',
+				31,
+			],
+			[
+				'Parameter #2 $f of function Bug11619Strict\customUsort expects callable(Stringable, Stringable): int, \'strnatcasecmp\' given.',
+				54,
+			],
+		]);
 	}
 
 	public function testBug13247(): void

Original file line number	Diff line number	Diff line change
`@@ -60,6 +60,4 @@ public function mustUseReturnValue(): TrinaryLogic;`
`60`	`60`
`61`	`61`	`public function getAsserts(): Assertions;`
`62`	`62`
`63`		`- public function isBuiltin(): TrinaryLogic;`
`64`		`-`
`65`	`63`	`}`
Original file line number	Diff line number	Diff line change
`@@ -179,14 +179,4 @@ public function getAsserts(): Assertions`
`179`	`179`	`return $this->function->getAsserts();`
`180`	`180`	`}`
`181`	`181`
`182`		`- public function isBuiltin(): TrinaryLogic`
`183`		`- {`
`184`		`- $isBuiltin = $this->function->isBuiltin();`
`185`		`- if ($isBuiltin instanceof TrinaryLogic) {`
`186`		`- return $isBuiltin;`
`187`		`- }`
`188`		`-`
`189`		`- return TrinaryLogic::createFromBoolean($isBuiltin);`
`190`		`- }`
`191`		`-`
`192`	`182`	`}`
Original file line number	Diff line number	Diff line change
`@@ -37,7 +37,6 @@ public function __construct(`
`37`	`37`	`private array $usedVariables,`
`38`	`38`	`private TrinaryLogic $acceptsNamedArguments,`
`39`	`39`	`private TrinaryLogic $mustUseReturnValue,`
`40`		`- private TrinaryLogic $isBuiltinCallable,`
`41`	`40`	`private ?Assertions $assertions = null,`
`42`	`41`	`)`
`43`	`42`	`{`
`@@ -93,9 +92,4 @@ public function getAsserts(): Assertions`
`93`	`92`	`return $this->assertions ?? Assertions::createEmpty();`
`94`	`93`	`}`
`95`	`94`
`96`		`- public function isBuiltin(): TrinaryLogic`
`97`		`- {`
`98`		`- return $this->isBuiltinCallable;`
`99`		`- }`
`100`		`-`
`101`	`95`	`}`
Original file line number	Diff line number	Diff line change
`@@ -130,7 +130,6 @@ public static function resolve(array $argTypes, ParametersAcceptor $parametersAc`
`130`	`130`	`$originalParametersAcceptor->getUsedVariables(),`
`131`	`131`	`$originalParametersAcceptor->acceptsNamedArguments(),`
`132`	`132`	`$originalParametersAcceptor->mustUseReturnValue(),`
`133`		`- $originalParametersAcceptor->isBuiltin(),`
`134`	`133`	`$originalParametersAcceptor->getAsserts(),`
`135`	`134`	`);`
`136`	`135`	`}`
Original file line number	Diff line number	Diff line change
`@@ -98,9 +98,4 @@ public function getAsserts(): Assertions`
`98`	`98`	`return Assertions::createEmpty();`
`99`	`99`	`}`
`100`	`100`
`101`		`- public function isBuiltin(): TrinaryLogic`
`102`		`- {`
`103`		`- return TrinaryLogic::createMaybe();`
`104`		`- }`
`105`		`-`
`106`	`101`	`}`
Original file line number	Diff line number	Diff line change
`@@ -29,7 +29,6 @@ public function __construct(`
`29`	`29`	`private array $usedVariables,`
`30`	`30`	`private TrinaryLogic $acceptsNamedArguments,`
`31`	`31`	`private TrinaryLogic $mustUseReturnValue,`
`32`		`- private TrinaryLogic $isBuiltinCallable,`
`33`	`32`	`private ?Assertions $assertions = null,`
`34`	`33`	`)`
`35`	`34`	`{`
`@@ -125,9 +124,4 @@ public function getAsserts(): Assertions`
`125`	`124`	`return $this->assertions ?? Assertions::createEmpty();`
`126`	`125`	`}`
`127`	`126`
`128`		`- public function isBuiltin(): TrinaryLogic`
`129`		`- {`
`130`		`- return $this->isBuiltinCallable;`
`131`		`- }`
`132`		`-`
`133`	`127`	`}`
Original file line number	Diff line number	Diff line change
`@@ -108,9 +108,4 @@ public function getAsserts(): Assertions`
`108`	`108`	`return Assertions::createEmpty();`
`109`	`109`	`}`
`110`	`110`
`111`		`- public function isBuiltin(): TrinaryLogic`
`112`		`- {`
`113`		`- return TrinaryLogic::createMaybe();`
`114`		`- }`
`115`		`-`
`116`	`111`	`}`
Original file line number	Diff line number	Diff line change
`@@ -139,7 +139,7 @@ public function accepts(Type $type, bool $strictTypes): AcceptsResult`
`139`	`139`	`return $type->isAcceptedBy($this, $strictTypes);`
`140`	`140`	`}`
`141`	`141`
`142`		`- return $this->isSuperTypeOfInternal($type, true)->toAcceptsResult();`
	`142`	`+ return $this->isSuperTypeOfInternal($type, true, $strictTypes)->toAcceptsResult();`
`143`	`143`	`}`
`144`	`144`
`145`	`145`	`public function isSuperTypeOf(Type $type): IsSuperTypeOfResult`
`@@ -151,7 +151,7 @@ public function isSuperTypeOf(Type $type): IsSuperTypeOfResult`
`151`	`151`	`return $this->isSuperTypeOfInternal($type, false);`
`152`	`152`	`}`
`153`	`153`
`154`		`- private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny): IsSuperTypeOfResult`
	`154`	`+ private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny, bool $strictTypes = true): IsSuperTypeOfResult`
`155`	`155`	`{`
`156`	`156`	`$isCallable = new IsSuperTypeOfResult($type->isCallable(), []);`
`157`	`157`	`if ($isCallable->no()) {`
`@@ -180,12 +180,11 @@ private function isSuperTypeOfInternal(Type $type, bool $treatMixedAsAny): IsSup`
`180`	`180`
`181`	`181`	`$variantsResult = null;`
`182`	`182`	`foreach ($type->getCallableParametersAcceptors($scope) as $variant) {`
`183`		`- $isBuiltinCallable = $variant->isBuiltin()->yes();`
`184`	`183`	`$variant = ParametersAcceptorSelector::selectFromTypes($parameterTypes, [$variant], false);`
`185`	`184`	`if (!$variant instanceof CallableParametersAcceptor) {`
`186`	`185`	`return IsSuperTypeOfResult::createNo([]);`
`187`	`186`	`}`
`188`		`- $isSuperType = CallableTypeHelper::isParametersAcceptorSuperTypeOf($this, $variant, $treatMixedAsAny, !$isBuiltinCallable);`
	`187`	`+ $isSuperType = CallableTypeHelper::isParametersAcceptorSuperTypeOf($this, $variant, $treatMixedAsAny, $strictTypes);`
`189`	`188`	`if ($variantsResult === null) {`
`190`	`189`	`$variantsResult = $isSuperType;`
`191`	`190`	`} else {`
`@@ -405,11 +404,6 @@ public function getAsserts(): Assertions`
`405`	`404`	`return Assertions::createEmpty();`
`406`	`405`	`}`
`407`	`406`
`408`		`- public function isBuiltin(): TrinaryLogic`
`409`		`- {`
`410`		`- return TrinaryLogic::createMaybe();`
`411`		`- }`
`412`		`-`
`413`	`407`	`public function toNumber(): Type`
`414`	`408`	`{`
`415`	`409`	`return new ErrorType();`