Fix #3927 - prevent crash with bad type ref

src/Psalm/Internal/PhpVisitor/ReflectorVisitor.php

@@ -609,8 +609,9 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements PhpParse
                 }
             }
 
-            $classlike_storage->type_aliases = \array_map(
+            $converted_aliases = \array_map(
                 function (TypeAlias\InlineTypeAlias $t) {
+                    try {
                         $union = TypeParser::parseTokens(
                             $t->replacement_tokens,
                             null,
@@ -623,10 +624,24 @@ class ReflectorVisitor extends PhpParser\NodeVisitorAbstract implements PhpParse
                         return new TypeAlias\ClassTypeAlias(
                             \array_values($union->getAtomicTypes())
                         );
+                    } catch (\Exception $e) {
+                        return null;
+                    }
                 },
                 $this->classlike_type_aliases
             );
 
+            foreach ($converted_aliases as $key => $type) {
+                if (!$type) {
+                    $classlike_storage->docblock_issues[] = new InvalidDocblock(
+                        '@psalm-type ' . $key . ' contains invalid references',
+                        new CodeLocation($this->file_scanner, $node, null, true)
+                    );
+                }
+            }
+
+            $classlike_storage->type_aliases = \array_filter($converted_aliases);
+
             $this->classlike_type_aliases = [];
 
             if ($classlike_storage->has_visitor_issues) {

tests/TypeAnnotationTest.php

@@ -386,6 +386,17 @@ class TypeAnnotationTest extends TestCase
                 }',
                 'error_message' => 'UndefinedDocblockClass',
             ],
+            'noCrashWithPriorReference' => [
+                '<?php
+                    /**
+                     * @psalm-type _C=array{c:_CC}
+                     * @psalm-type _CC=float
+                     */
+                    class A {
+
+                    }',
+                'error_message' => 'InvalidDocblock',
+            ],
         ];
     }
 }