[DeadCode] Handle always terminated TryCatch on RemoveUnreachableStat…

…ementRector (#2545)

* [DeadCode] Handle always terminated TryCatch on RemoveUnreachableStatementRector

* implemented 🎉

rules-tests/DeadCode/Rector/Stmt/RemoveUnreachableStatementRector/Fixture/always_terminated_try_catch.php.inc

@@ -0,0 +1,41 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\Stmt\RemoveUnreachableStatementRector\Fixture;
+
+use Exception;
+
+class AlwaysTerminatedTryCatch
+{
+    public function run()
+    {
+        try {
+            return something();
+        } catch (Exception $e) {
+            return null;
+        }
+
+        echo 'never executed';
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\Stmt\RemoveUnreachableStatementRector\Fixture;
+
+use Exception;
+
+class AlwaysTerminatedTryCatch
+{
+    public function run()
+    {
+        try {
+            return something();
+        } catch (Exception $e) {
+            return null;
+        }
+    }
+}
+
+?>

rules-tests/DeadCode/Rector/Stmt/RemoveUnreachableStatementRector/Fixture/try_return_finally_comment.php.inc

@@ -0,0 +1,37 @@
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\Stmt\RemoveUnreachableStatementRector\Fixture;
+
+class TryFinallyOnlyCommentStmt
+{
+    public function setMultiple($values, $ttl = null): bool
+    {
+        try {
+            return true;
+        } finally {
+            // only comment
+        }
+
+        return false;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DeadCode\Rector\Stmt\RemoveUnreachableStatementRector\Fixture;
+
+class TryFinallyOnlyCommentStmt
+{
+    public function setMultiple($values, $ttl = null): bool
+    {
+        try {
+            return true;
+        } finally {
+            // only comment
+        }
+    }
+}
+
+?>

rules/DeadCode/Rector/Stmt/RemoveUnreachableStatementRector.php

@@ -10,7 +10,6 @@
 use PhpParser\Node\Stmt\Break_;
 use PhpParser\Node\Stmt\Continue_;
 use PhpParser\Node\Stmt\Expression;
-use PhpParser\Node\Stmt\Finally_;
 use PhpParser\Node\Stmt\Goto_;
 use PhpParser\Node\Stmt\InlineHTML;
 use PhpParser\Node\Stmt\Label;
@@ -19,8 +18,8 @@
 use PhpParser\Node\Stmt\Throw_;
 use PhpParser\Node\Stmt\TryCatch;
 use Rector\Core\Contract\PhpParser\Node\StmtsAwareInterface;
+use Rector\Core\NodeAnalyzer\TryCatchAnalyzer;
 use Rector\Core\Rector\AbstractRector;
-use Rector\NodeTypeResolver\Node\AttributeKey;
 use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
 use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
 
@@ -31,6 +30,10 @@
  */
 final class RemoveUnreachableStatementRector extends AbstractRector
 {
+    public function __construct(private readonly TryCatchAnalyzer $tryCatchAnalyzer)
+    {
+    }
+
     public function getRuleDefinition(): RuleDefinition
     {
         return new RuleDefinition('Remove unreachable statements', [
@@ -142,24 +145,6 @@ private function shouldRemove(Stmt $previousStmt, Stmt $currentStmt): bool
             return false;
         }
 
-        $isUnreachable = $currentStmt->getAttribute(AttributeKey::IS_UNREACHABLE);
-        if ($isUnreachable !== true) {
-            return false;
-        }
-
-        if (! $previousStmt->finally instanceof Finally_) {
-            return false;
-        }
-
-        return $this->cleanNop($previousStmt->finally->stmts) !== [];
-    }
-
-    /**
-     * @param Stmt[] $stmts
-     * @return Stmt[]
-     */
-    private function cleanNop(array $stmts): array
-    {
-        return array_filter($stmts, fn (Stmt $stmt): bool => ! $stmt instanceof Nop);
+        return $this->tryCatchAnalyzer->isAlwaysTerminated($previousStmt);
     }
 }

src/NodeAnalyzer/TryCatchAnalyzer.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Core\NodeAnalyzer;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Exit_;
+use PhpParser\Node\Stmt;
+use PhpParser\Node\Stmt\Expression;
+use PhpParser\Node\Stmt\Finally_;
+use PhpParser\Node\Stmt\Return_;
+use PhpParser\Node\Stmt\Throw_;
+use PhpParser\Node\Stmt\TryCatch;
+
+final class TryCatchAnalyzer
+{
+    /**
+     * @var array<class-string<Node>>
+     */
+    private const TERMINATED_NODES = [Return_::class, Throw_::class];
+
+    public function isAlwaysTerminated(TryCatch $tryCatch): bool
+    {
+        if ($tryCatch->finally instanceof Finally_ && $this->isTerminated($tryCatch->finally->stmts)) {
+            return true;
+        }
+
+        foreach ($tryCatch->catches as $catch) {
+            if (! $this->isTerminated($catch->stmts)) {
+                return false;
+            }
+        }
+
+        return $this->isTerminated($tryCatch->stmts);
+    }
+
+    /**
+     * @param Stmt[] $stmts
+     */
+    private function isTerminated(array $stmts): bool
+    {
+        if ($stmts === []) {
+            return false;
+        }
+
+        $lastKey = array_key_last($stmts);
+        $lastNode = $stmts[$lastKey];
+
+        if ($lastNode instanceof Expression) {
+            return $lastNode->expr instanceof Exit_;
+        }
+
+        return in_array($lastNode::class, self::TERMINATED_NODES, true);
+    }
+}