[clang] Fix crash when passing a braced-init list to a parentehsized aggregate init expression

The previous code incorrectly assumed that we would never call
warnBracedScalarInit(...) with a EK_ParenAggInitMember. This patch fixes
the bug by warning when a scalar member is initialized via a braced-init
list when performing a parentehsized aggregate initialization. This
behavior is consistent with parentehsized list aggregate initialization.

Fixes #63008

Reviewed By: shafik

Differential Revision: https://reviews.llvm.org/D151763

Author: alanzhao1

clang/docs/ReleaseNotes.rst

@@ -460,6 +460,9 @@ Bug Fixes in This Version
 - Fix crash when diagnosing default comparison method.
   (`#62791 <https://github.com/llvm/llvm-project/issues/62791>`_) and
   (`#62102 <https://github.com/llvm/llvm-project/issues/62102>`_).
+- Fix crash when passing a braced initializer list to a parentehsized aggregate
+  initialization expression.
+  (`#63008 <https://github.com/llvm/llvm-project/issues/63008>`_).
 
 Bug Fixes to Compiler Builtins
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

clang/lib/Sema/SemaInit.cpp

@@ -1158,6 +1158,7 @@ static void warnBracedScalarInit(Sema &S, const InitializedEntity &Entity,
   case InitializedEntity::EK_Parameter_CF_Audited:
   case InitializedEntity::EK_TemplateParameter:
   case InitializedEntity::EK_Result:
+  case InitializedEntity::EK_ParenAggInitMember:
     // Extra braces here are suspicious.
     DiagID = diag::warn_braces_around_init;
     break;
@@ -1192,7 +1193,6 @@ static void warnBracedScalarInit(Sema &S, const InitializedEntity &Entity,
   case InitializedEntity::EK_LambdaToBlockConversionBlockElement:
   case InitializedEntity::EK_Binding:
   case InitializedEntity::EK_StmtExprResult:
-  case InitializedEntity::EK_ParenAggInitMember:
     llvm_unreachable("unexpected braced scalar init");
   }
 

clang/test/SemaCXX/paren-list-agg-init.cpp

@@ -266,3 +266,9 @@ O o2(0, 0); // no-error
 O o3(0);
 // expected-error@-1 {{reference member of type 'int &&' uninitialized}}
 }
+
+namespace gh63008 {
+auto a = new A('a', {1.1});
+// expected-warning@-1 {{braces around scalar init}}
+// beforecxx20-warning@-2 {{aggregate initialization of type 'A' from a parenthesized list of values is a C++20 extension}}
+}