[clang] [clang][Sema] Fix the continue and break scope for while loops (PR #152606)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Oliver Hunt (ojhunt)

<details>
<summary>Changes</summary>

Make sure we don't push the break and continue scope for a while loop until after we have evaluated the condition.

---
Full diff: https://github.com/llvm/llvm-project/pull/152606.diff


3 Files Affected:

- (modified) clang/docs/ReleaseNotes.rst (+2) 
- (modified) clang/lib/Parse/ParseStmt.cpp (+2-1) 
- (added) clang/test/Sema/while-loop-condition-scope.c (+11) 


``````````diff
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 0e9fcaa5fac6a..4062c4b7a6fdb 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -161,6 +161,8 @@ Bug Fixes in This Version
   targets that treat ``_Float16``/``__fp16`` as native scalar types. Previously
   the warning was silently lost because the operands differed only by an implicit
   cast chain. (#GH149967).
+- Correct the continue and break scope for while statements to be after the
+  condition is evaluated.
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
index bf1978c22ee9f..b1b700951231f 100644
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -1734,7 +1734,6 @@ StmtResult Parser::ParseWhileStatement(SourceLocation *TrailingElseLoc) {
                  Scope::DeclScope  | Scope::ControlScope;
   else
     ScopeFlags = Scope::BreakScope | Scope::ContinueScope;
-  ParseScope WhileScope(this, ScopeFlags);
 
   // Parse the condition.
   Sema::ConditionResult Cond;
@@ -1744,6 +1743,8 @@ StmtResult Parser::ParseWhileStatement(SourceLocation *TrailingElseLoc) {
                                 Sema::ConditionKind::Boolean, LParen, RParen))
     return StmtError();
 
+  ParseScope WhileScope(this, ScopeFlags);
+
   // OpenACC Restricts a while-loop inside of certain construct/clause
   // combinations, so diagnose that here in OpenACC mode.
   SemaOpenACC::LoopInConstructRAII LCR{getActions().OpenACC()};
diff --git a/clang/test/Sema/while-loop-condition-scope.c b/clang/test/Sema/while-loop-condition-scope.c
new file mode 100644
index 0000000000000..d87362bdc668d
--- /dev/null
+++ b/clang/test/Sema/while-loop-condition-scope.c
@@ -0,0 +1,11 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s 
+
+void f() {
+  while (({ continue; 1; })) {
+    // expected-error at -1 {{'continue' statement not in loop statement}}
+
+  }
+  while (({ break; 1; })) {
+    // expected-error at -1 {{'break' statement not in loop or switch statement}}
+  }
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/152606