Crash because Definition->type is null for a function

[lumpysimon]

Indexing a WordPress site, PHP7.1.1 on OSX, after about 15 mins of indexing I'm getting the The PHP Language Server server crashed 5 times in the last 3 minutes. The server will not be restarted error. Here's the stack trace:

extensionHost.ts:282 [Extension Host] TypeError: Return value of LanguageServer\DefinitionResolver::resolveExpressionNodeToType() must implement interface phpDocumentor\Reflection\Type, null returned in /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/felixfbecker/language-server/src/DefinitionResolver.php:444
Stack trace:
#0 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/felixfbecker/language-server/src/DefinitionResolver.php(238): LanguageServer\DefinitionResolver->resolveExpressionNodeToType(Object(PhpParser\Node\Expr\FuncCall))
#1 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/felixfbecker/language-server/src/NodeVisitor/ReferencesCollector.php(38): LanguageServer\DefinitionResolver->resolveReferenceNodeToFqn(Object(PhpParser\Node\Expr\MethodCall))
#2 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(108): LanguageServer\NodeVisitor\ReferencesCollector->enterNode(Object(PhpParser\Node\Expr\MethodCall))
#3 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(171): PhpParser\NodeTraverser->traverseNode(Object(PhpParser\Node\Expr\Assign))
#4 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(101): PhpParser\NodeTraverser->traverseArray(Array)
#5 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(171): PhpParser\NodeTraverser->traverseNode(Object(PhpParser\Node\Stmt\If_))
#6 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(101): PhpParser\NodeTraverser->traverseArray(Array)
#7 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(171): PhpParser\NodeTraverser->traverseNode(Object(PhpParser\Node\Stmt\Foreach_))
#8 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(101): PhpParser\NodeTraverser->traverseArray(Array)
#9 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(171): PhpParser\NodeTraverser->traverseNode(Object(PhpParser\Node\Stmt\Foreach_))
#10 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(101): PhpParser\NodeTraverser->traverseArray(Array)
#11 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(171): PhpParser\NodeTraverser->traverseNode(Object(PhpParser\Node\Stmt\ClassMethod))
#12 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(101): PhpParser\NodeTraverser->traverseArray(Array)
#13 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(171): PhpParser\NodeTraverser->traverseNode(Object(PhpParser\Node\Stmt\Class_))
#14 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(101): PhpParser\NodeTraverser->traverseArray(Array)
#15 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(171): PhpParser\NodeTraverser->traverseNode(Object(PhpParser\Node\Stmt\If_))
#16 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/nikic/php-parser/lib/PhpParser/NodeTraverser.php(85): PhpParser\NodeTraverser->traverseArray(Array)
#17 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/felixfbecker/language-server/src/PhpDocument.php(205): PhpParser\NodeTraverser->traverse(Array)
#18 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/felixfbecker/language-server/src/PhpDocument.php(119): LanguageServer\PhpDocument->updateContent('<?php\n\n/*\n\tPlug...')
#19 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/felixfbecker/language-server/src/PhpDocumentLoader.php(134): LanguageServer\PhpDocument->__construct('file:///private...', '<?php\n\n/*\n\tPlug...', Object(LanguageServer\Index\Index), Object(LanguageServer\Parser), Object(phpDocumentor\Reflection\DocBlockFactory), Object(LanguageServer\DefinitionResolver))
#20 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/felixfbecker/language-server/src/PhpDocumentLoader.php(113): LanguageServer\PhpDocumentLoader->create('file:///private...', '<?php\n\n/*\n\tPlug...')
#21 [internal function]: LanguageServer\PhpDocumentLoader->LanguageServer\{closure}()
#22 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/sabre/event/lib/coroutine.php(70): Generator->send('<?php\n\n/*\n\tPlug...')
#23 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/sabre/event/lib/Promise.php(242): Sabre\Event\{closure}('<?php\n\n/*\n\tPlug...')
#24 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/sabre/event/lib/Loop/Loop.php(261): Sabre\Event\Promise->Sabre\Event\{closure}()
#25 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/sabre/event/lib/Loop/Loop.php(215): Sabre\Event\Loop\Loop->runNextTicks()
#26 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/sabre/event/lib/Loop/Loop.php(194): Sabre\Event\Loop\Loop->tick(true)
#27 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/sabre/event/lib/Loop/functions.php(122): Sabre\Event\Loop\Loop->run()
#28 /Users/myuserhere/.vscode/extensions/felixfbecker.php-intellisense-1.1.2/vendor/felixfbecker/language-server/bin/php-language-server.php(102): Sabre\Event\Loop\run()
#29 {main}
d.logExtensionHostMessage @ extensionHost.ts:282
(anonymous function) @ extensionHost.ts:137
emitTwo @ events.js:106
emit @ events.js:191
process.nextTick @ internal/child_process.js:744
_combinedTickCallback @ internal/process/next_tick.js:67
_tickCallback @ internal/process/next_tick.js:98
messageService.ts:126 The PHP Language Server server crashed 5 times in the last 3 minutes. The server will not be restarted.
e.doShow @ messageService.ts:126
e.show @ messageService.ts:105
(anonymous function) @ mainThreadMessageService.ts:55
n.Class.derive._oncancel @ winjs.base.raw.js:1641
t.$showMessage @ mainThreadMessageService.ts:25
e.handle @ abstractThreadService.ts:34
s @ ipcRemoteCom.ts:275
f @ ipcRemoteCom.ts:231
_combinedTickCallback @ internal/process/next_tick.js:67
_tickCallback @ internal/process/next_tick.js:98

[felixfbecker]

Probably fixed by #292, which seems to have broken a test though. If you wanna look into that I can merge it, don't have time right now

[lumpysimon]

I would help if I could, but it's way outside my field of knowledge I'm afraid.

[johnrom]

This is not fixed by #292

[johnrom]

@felixfbecker

this line should check if $def->type is null:

$def = $this->index->getDefinition($fqn, true);

if ($def !== null && $def->type !== null) {
    return $def->type;
}

[felixfbecker]

@johnrom thanks for looking into this, but the real issue is that $def->type is null in the Definition object, not that case is not handled.

[johnrom]

I figured that was probably a problem (but I'll survive without that fix for now :) ). I have a file that causes this issue, if you'd like me to attach it.

[Talv]

I did some digging on this. The issue is actually pretty trivial. It occurs for non namespaced symbols, where functions and classes have clashing names.

Shortest snippet of code that will trigger exception:

class acf_local {
}
acf_local()->enabled;

When trying to resolve type definition of acf_local() it incorrectly assumes it's clas acf_local. Obviously class doesn't define ->type, as it is type itself - thus the exception.
It happens because of missing () here.
It doesn't occur for namespaced symbols because they have namespacedName attribute set (correctly) in different part of code.

edit:
Wrong assumption about namespacedName.