[explicit-resource-management] disallow using in switch cases

rmahdav · V8 LUCI CQ · commit 044b9b6f589d · 2025-05-02T09:57:32.000-07:00
This CL disallows `using` and `await using` in switch cases. This was a normative change that got consensus in TC39 meetings: rbuckton/ecma262#14 Bug: 409478039 Change-Id: I077e75d7d0d632c8b34150cfc76e4903984d6091 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/6500234 Reviewed-by: Shu-yu Guo <syg@chromium.org> Commit-Queue: Rezvan Mahdavi Hezaveh <rezvan@chromium.org> Cr-Commit-Position: refs/heads/main@{#100037}
diff --git a/src/parsing/parser-base.h b/src/parsing/parser-base.h
@@ -1165,16 +1165,18 @@ class ParserBase {
   }
   bool is_using_allowed() const {
     // UsingDeclaration and AwaitUsingDeclaration are Syntax Errors if the goal
-    // symbol is Script. UsingDeclaration and AwaitUsingDeclaration are not
-    // contained, either directly or indirectly, within a Block, CaseBlock,
-    // ForStatement, ForInOfStatement, FunctionBody, GeneratorBody,
+    // symbol is Script. UsingDeclaration and AwaitUsingDeclaration are Syntax
+    // Errors if they are not contained, either directly or indirectly, within a
+    // Block, ForStatement, ForInOfStatement, FunctionBody, GeneratorBody,
     // AsyncGeneratorBody, AsyncFunctionBody, ClassStaticBlockBody, or
-    // ClassBody. Unless the current scope's ScopeType is ScriptScope, the
+    // ClassBody. They are disallowed in 'bare' switch cases.
+    // Unless the current scope's ScopeType is ScriptScope, the
     // current position is directly or indirectly within one of the productions
     // listed above since they open a new scope.
-    return ((scope()->scope_type() != SCRIPT_SCOPE &&
-             scope()->scope_type() != EVAL_SCOPE) ||
-            scope()->scope_type() == REPL_MODE_SCOPE);
+    return (((scope()->scope_type() != SCRIPT_SCOPE &&
+              scope()->scope_type() != EVAL_SCOPE) ||
+             scope()->scope_type() == REPL_MODE_SCOPE) &&
+            !scope()->is_nonlinear());
   }
   bool IsNextUsingKeyword(Token::Value token_after_using, bool is_await_using) {
     // using and await using declarations in for-of statements must be followed
diff --git a/test/test262/test262.status b/test/test262/test262.status
@@ -1233,6 +1233,10 @@
   # May OOM fatally
   'staging/sm/regress/regress-610026': [SKIP],
 
+  # https://github.com/rbuckton/ecma262/pull/14
+  'staging/explicit-resource-management/await-using-in-switch-case-block': [SKIP],
+  'staging/explicit-resource-management/call-dispose-methods': [SKIP],
+
   ############################ SLOW TESTS #############################
 
   'annexB/built-ins/RegExp/RegExp-leading-escape-BMP': [PASS, SLOW],
diff --git a/test/unittests/parser/decls-unittest.cc b/test/unittests/parser/decls-unittest.cc
@@ -1082,6 +1082,24 @@ TEST_F(DeclsTest, TestUsing) {
                   EXPECT_ERROR);
     context.Check("{var using; \n using = 42;}", EXPECT_RESULT,
                   Number::New(isolate(), 42));
+    context.Check(
+        "let label = \"1\"; \n switch (label) { \n case 1: \n let y = 2; \n"
+        "using x = { \n "
+        "     value: 1, \n "
+        "      [Symbol.dispose]() { \n "
+        "       return 42; \n "
+        "     } \n "
+        "   };  }",
+        EXPECT_ERROR);
+    context.Check(
+        "let label = \"1\"; \n switch (label) { \n case 1: {\n let y = 2; \n"
+        "using x = { \n "
+        "     value: 1, \n "
+        "      [Symbol.dispose]() { \n "
+        "       return 42; \n "
+        "     } \n "
+        "   };  } }",
+        EXPECT_RESULT, Undefined(isolate()));
   }
 }
 
@@ -1144,6 +1162,17 @@ TEST_F(DeclsTest, TestAwaitUsing) {
         " } } \n "
         " f(); ",
         EXPECT_ERROR);
+    context.Check(
+        "async function f() {let label = \"1\"; \n switch (label){ \n case 1: "
+        "\n let y = 2;"
+        "\n await using x = { \n "
+        "     value: 1, \n "
+        "      [Symbol.asyncDispose]() { \n "
+        "       classStaticBlockBodyValues.push(42); \n "
+        "     } \n "
+        "   }; \n }"
+        "} \n f();",
+        EXPECT_ERROR);
   }
 }
 
