From 6f47cdd51341344c0e32630e19e72c94cd25f34e Mon Sep 17 00:00:00 2001 From: Eric Fiselier Date: Wed, 24 Oct 2018 22:38:49 +0000 Subject: [PATCH] [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 git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@345211 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Sema/SemaExprCXX.cpp | 5 +++-- ...cxx03-aligned-allocation-unscoped-enum.cpp | 21 +++++++++++++++++++ 2 files changed, 24 insertions(+), 2 deletions(-) create mode 100644 test/SemaCXX/cxx03-aligned-allocation-unscoped-enum.cpp diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp index 1349b5af6a..03ec20601c 100644 --- a/lib/Sema/SemaExprCXX.cpp +++ b/lib/Sema/SemaExprCXX.cpp @@ -1515,8 +1515,9 @@ 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 && ParamTy->isIntegerType(); } // In CUDA, determine how much we'd like / dislike to call this. diff --git a/test/SemaCXX/cxx03-aligned-allocation-unscoped-enum.cpp b/test/SemaCXX/cxx03-aligned-allocation-unscoped-enum.cpp new file mode 100644 index 0000000000..8bafaec26d --- /dev/null +++ b/test/SemaCXX/cxx03-aligned-allocation-unscoped-enum.cpp @@ -0,0 +1,21 @@ +// RUN: %clang_cc1 -std=c++03 %s -faligned-allocation \ +// RUN: -emit-llvm -o - | FileCheck %s + +// Ensure Clang doesn't confuse std::align_val_t with the sized deallocation +// parameter when the enum type is unscoped. Libc++ does this in C++03 in order +// to support aligned allocation in that dialect. + +using size_t = __decltype(sizeof(0)); + +namespace std { +enum align_val_t { zero = size_t(0), + max = size_t(-1) }; +} + +// CHECK-LABEL: define void @_Z1fPi( +void f(int *p) { + // CHECK-NOT: call void @_ZdlPvSt11align_val_t( + // CHECK: call void @_ZdlPv( + // CHECK: ret void + delete p; +} -- 2.40.0