Report uses of deprecated constants

src/Reflection/BetterReflection/BetterReflectionProvider.php

@@ -365,6 +365,8 @@ public function getConstant(Node\Name $nameNode, ?NamespaceAnswerer $namespaceAn
 			$constantName,
 			$constantValueType,
 			$fileName,
+			$this->fileTypeMapper,
+			$constantReflection->getDocComment(),
 		);
 	}
 

src/Reflection/Constant/RuntimeConstantReflection.php

@@ -2,17 +2,28 @@
 
 namespace PHPStan\Reflection\Constant;
 
+use PHPStan\PhpDoc\ResolvedPhpDocBlock;
 use PHPStan\Reflection\GlobalConstantReflection;
 use PHPStan\TrinaryLogic;
+use PHPStan\Type\FileTypeMapper;
 use PHPStan\Type\Type;
 
 class RuntimeConstantReflection implements GlobalConstantReflection
 {
 
+	private false|ResolvedPhpDocBlock $resolvedPhpDocBlock = false;
+
+	private ?string $deprecatedDescription = null;
+
+	/**
+	 * @param non-empty-string|null $docComment
+	 */
 	public function __construct(
 		private string $name,
 		private Type $valueType,
 		private ?string $fileName,
+		private FileTypeMapper $fileTypeMapper,
+		private ?string $docComment,
 	)
 	{
 	}
@@ -34,12 +45,43 @@ public function getFileName(): ?string
 
 	public function isDeprecated(): TrinaryLogic
 	{
-		return TrinaryLogic::createNo();
+		$resolvedPhpDoc = $this->getResolvedPhpDoc();
+		if ($resolvedPhpDoc === null) {
+			return TrinaryLogic::createNo();
+		}
+
+		return TrinaryLogic::createFromBoolean($resolvedPhpDoc->isDeprecated());
 	}
 
 	public function getDeprecatedDescription(): ?string
 	{
-		return null;
+		if ($this->deprecatedDescription === null && $this->isDeprecated()->yes()) {
+			$resolvedPhpDoc = $this->getResolvedPhpDoc();
+			if ($resolvedPhpDoc !== null && $resolvedPhpDoc->getDeprecatedTag() !== null) {
+				$this->deprecatedDescription = $resolvedPhpDoc->getDeprecatedTag()->getMessage();
+			}
+		}
+
+		return $this->deprecatedDescription;
+	}
+
+	/** @return non-empty-string|null */
+	public function getDocComment(): ?string
+	{
+		return $this->docComment;
+	}
+
+	private function getResolvedPhpDoc(): ?ResolvedPhpDocBlock
+	{
+		if ($this->docComment === null) {
+			return null;
+		}
+
+		if ($this->resolvedPhpDocBlock !== false) {
+			return $this->resolvedPhpDocBlock;
+		}
+
+		return $this->resolvedPhpDocBlock = $this->fileTypeMapper->getResolvedPhpDoc($this->getFileName(), null, null, null, $this->docComment);
 	}
 
 	public function isInternal(): TrinaryLogic

tests/PHPStan/Reflection/Constant/RuntimeConstantReflectionTest.php

@@ -0,0 +1,47 @@
+<?php declare(strict_types = 1);
+
+namespace PHPStan\Reflection\Constant;
+
+use PhpParser\Node\Name;
+use PHPStan\Testing\PHPStanTestCase;
+use PHPStan\TrinaryLogic;
+
+class RuntimeConstantReflectionTest extends PHPStanTestCase
+{
+
+	public function dataDeprecatedConstants(): array
+	{
+		return [
+			[
+				new Name('\DeprecatedConst\FINE'),
+				TrinaryLogic::createNo(),
+				null,
+			],
+			[
+				new Name('\DeprecatedConst\MY_CONST'),
+				TrinaryLogic::createYes(),
+				null,
+			],
+			[
+				new Name('\DeprecatedConst\MY_CONST2'),
+				TrinaryLogic::createYes(),
+				"don't use it!",
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider dataDeprecatedConstants
+	 */
+	public function testDeprecatedConstants(Name $constName, TrinaryLogic $isDeprecated, ?string $deprecationMessage): void
+	{
+		require_once __DIR__ . '/data/deprecated-constant.php';
+
+		$reflectionProvider = $this->createReflectionProvider();
+
+		$this->assertTrue($reflectionProvider->hasConstant($constName, null));
+		$this->assertSame($isDeprecated, $reflectionProvider->getConstant($constName, null)->isDeprecated());
+		$this->assertSame($deprecationMessage, $reflectionProvider->getConstant($constName, null)->getDeprecatedDescription());
+	}
+
+}

tests/PHPStan/Reflection/Constant/data/deprecated-constant.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace DeprecatedConst;
+
+const FINE = '1';
+
+/**
+ * @deprecated
+ */
+const MY_CONST = '1';
+
+/**
+ * @deprecated don't use it!
+ */
+const MY_CONST2 = '1';