Use the correct alignment for uuid descriptors

The _GUID_ descriptors emitted by MSVC have alignment 8 for 64-bit
builds: we should do the same if the linker picks the "wrong" COMDAT.

llvm-svn: 264530

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 399b739..435d646 100644 (file)
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1458,8 +1458,8 @@ ConstantAddress CodeGenModule::GetAddrOfUuidDescriptor(
   std::string Name = "_GUID_" + Uuid.lower();
   std::replace(Name.begin(), Name.end(), '-', '_');
 
-  // Contains a 32-bit field.
-  CharUnits Alignment = CharUnits::fromQuantity(4);
+  // The UUID descriptor should be pointer aligned.
+  CharUnits Alignment = CharUnits::fromQuantity(PointerAlignInBytes);
 
   // Look for an existing global.
   if (llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name))

diff --git a/clang/test/CodeGenCXX/microsoft-uuidof.cpp b/clang/test/CodeGenCXX/microsoft-uuidof.cpp
index 2ac5f1b..62e4b88 100644 (file)
--- a/clang/test/CodeGenCXX/microsoft-uuidof.cpp
+++ b/clang/test/CodeGenCXX/microsoft-uuidof.cpp
@@ -1,5 +1,6 @@
 // RUN: %clang_cc1 -emit-llvm %s -o - -DDEFINE_GUID -triple=i386-pc-linux -fms-extensions | FileCheck %s --check-prefix=CHECK-DEFINE-GUID
 // RUN: %clang_cc1 -emit-llvm %s -o - -triple=i386-pc-linux -fms-extensions | FileCheck %s
+// RUN: %clang_cc1 -emit-llvm %s -o - -triple=x86_64-pc-linux -fms-extensions | FileCheck %s --check-prefix=CHECK-64
 // RUN: %clang_cc1 -emit-llvm %s -o - -DDEFINE_GUID -DWRONG_GUID -triple=i386-pc-linux -fms-extensions | FileCheck %s --check-prefix=CHECK-DEFINE-WRONG-GUID
 
 #ifdef DEFINE_GUID
@@ -36,6 +37,7 @@ GUID g = __uuidof(S1);
 // First global use of __uuidof(S1) forces the creation of the global.
 // CHECK: @_GUID_12345678_1234_1234_1234_1234567890ab = linkonce_odr constant { i32, i16, i16, [8 x i8] } { i32 305419896, i16 4660, i16 4660, [8 x i8] c"\124\124Vx\90\AB" }, comdat
 // CHECK: @gr = constant %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to %struct._GUID*), align 4
+// CHECK-64: @gr = constant %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to %struct._GUID*), align 8
 const GUID& gr = __uuidof(S1);
 
 // CHECK: @gp = global %struct._GUID* bitcast ({ i32, i16, i16, [8 x i8] }* @_GUID_12345678_1234_1234_1234_1234567890ab to %struct._GUID*), align 4