Do not export functions declared inside functions

The exported nodes of an analysed file are collected during the analysis,
which also reaches the function declarations inside function bodies. When the
file changes, the result cache restore parses it again with
ExportedNodeVisitor, which does not look inside function bodies. The two lists
never matched, so every edit of such a file looked like a symbol disappeared,
and all files with errors were re-analysed with it.

Inner named functions are not supported anyway (function.inner), so they are
left out of the exported nodes. On WordPress core, appending a comment to
wp-includes/canonical.php, which declares lowercase_octets() inside
redirect_canonical(), re-analysed 400 files. Now it re-analyses 1.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GdwtgiEHwkF5BTz73jgHQQ

Author: ondrejmirtes

.github/workflows/e2e-tests.yml

@@ -428,6 +428,20 @@ jobs:
               ../bashunit -a contains 'Result cache restored. 2 files will be reanalysed.' "$OUTPUT"
               ../bashunit -a not_contains 'Bar.php:10:Instantiated class ResultCacheE2EScannedExportedNodes\NewDep not found.' "$OUTPUT"
               ../bashunit -a contains 'Foo.php:10:Method ResultCacheE2EScannedExportedNodes\Foo::doFoo() should return int but returns string.' "$OUTPUT"
+          - script: |
+              cd e2e/result-cache-inner-function
+              OUTPUT=$(../bashunit -a exit_code "1" "../../bin/phpstan analyse -vv --error-format raw")
+              echo "$OUTPUT"
+              ../bashunit -a contains 'Outer.php:8:Inner named functions are not supported by PHPStan.' "$OUTPUT"
+              ../bashunit -a contains 'Other.php:10:Method ResultCacheE2EInnerFunction\Other::doOther() should return int but returns string.' "$OUTPUT"
+              # A function declared inside another function is not an exported node, so an edit of the
+              # file declaring it looks like no symbol appeared or disappeared: only the file itself is
+              # re-analysed, not every file with errors.
+              patch -b src/Outer.php < body.patch
+              INFO=$(../../bin/phpstan result-cache-info --json)
+              echo "$INFO"
+              ../bashunit -a equals 'true' "$(echo "$INFO" | jq --raw-output '.resultCacheUsed')"
+              ../bashunit -a equals '1' "$(echo "$INFO" | jq --raw-output '.filesToAnalyseCount')"
           - script: |
               cd e2e/result-cache-scanned-trait
               ../../bin/phpstan analyse

e2e/result-cache-inner-function/body.patch

@@ -0,0 +1,11 @@
+--- src/Outer.php
++++ src/Outer.php
+@@ -11,5 +11,7 @@
+ 		}
+ 	}
+ 
+-	return inner($s);
++	$lower = inner($s);
++
++	return $lower;
+ }

e2e/result-cache-inner-function/phpstan.neon

@@ -0,0 +1,5 @@
+parameters:
+	level: 8
+	tmpDir: tmp
+	paths:
+		- src

e2e/result-cache-inner-function/src/Other.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace ResultCacheE2EInnerFunction;
+
+class Other
+{
+
+	public function doOther(): int
+	{
+		return 'not an int';
+	}
+
+}

e2e/result-cache-inner-function/src/Outer.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace ResultCacheE2EInnerFunction;
+
+function outer(string $s): string
+{
+	if (!function_exists('ResultCacheE2EInnerFunction\inner')) {
+		function inner(string $s): string
+		{
+			return strtolower($s);
+		}
+	}
+
+	return inner($s);
+}

e2e/result-cache-inner-function/tmp/.gitignore

@@ -0,0 +1,2 @@
+*
+!.*

src/Dependency/DependencyResolver.php

@@ -164,7 +164,11 @@ public function resolveDependencies(Node $node, Scope $scope): ?NodeDependencies
 			$this->collectNodeDependencies($node, $scope, $dependenciesReflections, $dependenciesFilePaths);
 		}
 
+		// A function declared inside another function is not supported (function.inner), and the
+		// restore does not look inside function bodies for exported nodes (ExportedNodeVisitor):
+		// exporting it here would make every edit of its file look like a symbol disappeared.
 		$exportedNode = ($nodeProfile & self::PROFILE_EXPORT) !== 0
+			&& !($node instanceof Node\Stmt\Function_ && $scope->getFunction() !== null)
 			? $this->exportedNodeResolver->resolve($node, $this->nameScopeTracker->getNamespaceUses())
 			: null;