ConstFetch handler

Author: ondrejmirtes

src/Analyser/Generator/ExprHandler/ConstFetchHandler.php

@@ -0,0 +1,104 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Analyser\Generator\ExprHandler;
+
+use Generator;
+use PhpParser\Node\Expr;
+use PhpParser\Node\Expr\ConstFetch;
+use PhpParser\Node\Name\FullyQualified;
+use PhpParser\Node\Stmt;
+use PHPStan\Analyser\ConstantResolver;
+use PHPStan\Analyser\ExpressionContext;
+use PHPStan\Analyser\Generator\ExprAnalysisResult;
+use PHPStan\Analyser\Generator\ExprHandler;
+use PHPStan\Analyser\Generator\GeneratorScope;
+use PHPStan\Analyser\Generator\NodeCallbackRequest;
+use PHPStan\Analyser\Generator\SpecifiedTypesHelper;
+use PHPStan\Analyser\SpecifiedTypes;
+use PHPStan\DependencyInjection\AutowiredService;
+use PHPStan\Type\Constant\ConstantBooleanType;
+use PHPStan\Type\ErrorType;
+use PHPStan\Type\NullType;
+use PHPStan\Type\Type;
+use function strtolower;
+
+/**
+ * @implements ExprHandler<ConstFetch>
+ */
+#[AutowiredService]
+final class ConstFetchHandler implements ExprHandler
+{
+
+	public function __construct(
+		private ConstantResolver $constantResolver,
+		private SpecifiedTypesHelper $specifiedTypesHelper,
+	)
+	{
+	}
+
+	public function supports(Expr $expr): bool
+	{
+		return $expr instanceof ConstFetch;
+	}
+
+	public function analyseExpr(Stmt $stmt, Expr $expr, GeneratorScope $scope, ExpressionContext $context, ?callable $alternativeNodeCallback): Generator
+	{
+		yield new NodeCallbackRequest($expr->name, $scope, $alternativeNodeCallback);
+
+		$type = $this->getConstFetchType($expr, $scope);
+
+		return new ExprAnalysisResult(
+			$type,
+			$type,
+			$scope,
+			hasYield: false,
+			isAlwaysTerminating: false,
+			throwPoints: [],
+			impurePoints: [],
+			specifiedTruthyTypes: $this->specifiedTypesHelper->createDefaultSpecifiedTruthyTypes($expr),
+			specifiedFalseyTypes: $this->specifiedTypesHelper->createDefaultSpecifiedFalseyTypes($expr),
+			specifiedNullTypes: new SpecifiedTypes(),
+		);
+	}
+
+	private function getConstFetchType(ConstFetch $expr, GeneratorScope $scope): Type
+	{
+		$constName = (string) $expr->name;
+		$loweredConstName = strtolower($constName);
+		if ($loweredConstName === 'true') {
+			return new ConstantBooleanType(true);
+		} elseif ($loweredConstName === 'false') {
+			return new ConstantBooleanType(false);
+		} elseif ($loweredConstName === 'null') {
+			return new NullType();
+		}
+
+		$namespacedName = null;
+		if (!$expr->name->isFullyQualified() && $scope->getNamespace() !== null) {
+			$namespacedName = new FullyQualified([$scope->getNamespace(), $expr->name->toString()]);
+		}
+		$globalName = new FullyQualified($expr->name->toString());
+
+		foreach ([$namespacedName, $globalName] as $name) {
+			if ($name === null) {
+				continue;
+			}
+			$constFetch = new ConstFetch($name);
+			$exprType = $scope->getExpressionType($constFetch);
+			if ($exprType !== null) {
+				return $this->constantResolver->resolveConstantType(
+					$name->toString(),
+					$exprType,
+				);
+			}
+		}
+
+		$constantType = $this->constantResolver->resolveConstant($expr->name, $scope);
+		if ($constantType !== null) {
+			return $constantType;
+		}
+
+		return new ErrorType();
+	}
+
+}

tests/PHPStan/Analyser/Generator/data/gnsr.php

@@ -8,6 +8,7 @@
 use DivisionByZeroError;
 use function PHPStan\Testing\assertNativeType;
 use function PHPStan\Testing\assertType;
+use const PHP_VERSION_ID;
 
 class Foo
 {
@@ -470,3 +471,7 @@ function doFoo(): void {
 		assertType('470', __LINE__);
 	}
 }
+
+function (): void {
+	assertType('int<50207, 80599>', PHP_VERSION_ID);
+};