[SemaCXX] Unconfuse Clang when std::align_val_t is unscoped in C++03

Summary:
When -faligned-allocation is specified in C++03 libc++ defines std::align_val_t as an unscoped enumeration type (because Clang didn't provide scoped enumerations as an extension until 8.0).
Unfortunately Clang confuses the `align_val_t` overloads of delete with the sized deallocation overloads which aren't enabled. This caused Clang to call the aligned deallocation function as if it were the sized deallocation overload.

For example: https://godbolt.org/z/xXJELh

This patch fixes the confusion.

Reviewers: rsmith, EricWF

Reviewed By: EricWF

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D53508

llvm-svn: 345296

1 files changed, 5 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 1349b5af6aa..43e753636d1 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -1515,8 +1515,11 @@ namespace {
       if (FD->getNumParams() == NumBaseParams + 2)
         HasAlignValT = HasSizeT = true;
       else if (FD->getNumParams() == NumBaseParams + 1) {
-        HasSizeT = FD->getParamDecl(NumBaseParams)->getType()->isIntegerType();
-        HasAlignValT = !HasSizeT;
+        QualType ParamTy = FD->getParamDecl(NumBaseParams)->getType();
+        HasAlignValT = ParamTy->isAlignValT();
+        HasSizeT = !HasAlignValT;
+        assert((HasAlignValT || ParamTy->isIntegerType()) &&
+            "Candidate is not regular dealloc function");
       }
 
       // In CUDA, determine how much we'd like / dislike to call this.