If a try block terminates, don't consider the contents of the finally block to be dead code.

Fixes #48258.

Bug: #48258
Change-Id: Icf88c659f3258a723970d89882b58c75f8eff6d8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/231043
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Paul Berry <[email protected]>

Author: stereotype441

pkg/analyzer/lib/src/generated/resolver.dart

@@ -2445,10 +2445,10 @@ class ResolverVisitor extends ThrowingAstVisitor<void>
       flow.tryCatchStatement_bodyBegin();
     }
     body.accept(this);
+    nullSafetyDeadCodeVerifier.flowEnd(node.body);
+    nullSafetyDeadCodeVerifier.tryStatementEnter(node);
     if (catchClauses.isNotEmpty) {
       flow.tryCatchStatement_bodyEnd(body);
-      nullSafetyDeadCodeVerifier.flowEnd(node.body);
-      nullSafetyDeadCodeVerifier.tryStatementEnter(node);
 
       var catchLength = catchClauses.length;
       for (var i = 0; i < catchLength; ++i) {
@@ -2464,8 +2464,8 @@ class ResolverVisitor extends ThrowingAstVisitor<void>
       }
 
       flow.tryCatchStatement_end();
-      nullSafetyDeadCodeVerifier.tryStatementExit(node);
     }
+    nullSafetyDeadCodeVerifier.tryStatementExit(node);
 
     if (finallyBlock != null) {
       flow.tryFinallyStatement_finallyBegin(

pkg/analyzer/test/src/diagnostics/dead_code_test.dart

@@ -140,6 +140,24 @@ int f(Foo foo) {
       error(HintCode.DEAD_CODE, 111, 10),
     ]);
   }
+
+  test_try_finally() async {
+    await assertErrorsInCode('''
+main() {
+  try {
+    foo();
+    print('dead');
+  } finally {
+    print('alive');
+  }
+  print('dead');
+}
+Never foo() => throw 'exception';
+''', [
+      error(HintCode.DEAD_CODE, 32, 14),
+      error(HintCode.DEAD_CODE, 87, 14),
+    ]);
+  }
 }
 
 mixin DeadCodeTestCases on PubPackageResolutionTest {