[MS ABI] Don't crash on references to pointers to members in args

We know that a reference can always be dereferenced.  However, we don't
always know the number of bytes if the reference's pointee type is
incomplete.  This case was correctly handled but we didn't consider the
case where the type is complete but we cannot calculate its size for ABI
specific reasons.  In this specific case, a member pointer's size is
available only under certain conditions.

This fixes PR24703.

llvm-svn: 247188

diff --git a/clang/lib/CodeGen/CGCall.cpp b/clang/lib/CodeGen/CGCall.cpp
index ef90952..b54264b 100644 (file)
--- a/clang/lib/CodeGen/CGCall.cpp
+++ b/clang/lib/CodeGen/CGCall.cpp
@@ -1586,7 +1586,7 @@ void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
 
   if (const auto *RefTy = RetTy->getAs<ReferenceType>()) {
     QualType PTy = RefTy->getPointeeType();
-    if (!PTy->isIncompleteType() && PTy->isConstantSizeType())
+    if (getCXXABI().isTypeInfoCalculable(PTy) && PTy->isConstantSizeType())
       RetAttrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy)
                                         .getQuantity());
     else if (getContext().getTargetAddressSpace(PTy) == 0)
@@ -1698,7 +1698,7 @@ void CodeGenModule::ConstructAttributeList(const CGFunctionInfo &FI,
 
     if (const auto *RefTy = ParamType->getAs<ReferenceType>()) {
       QualType PTy = RefTy->getPointeeType();
-      if (!PTy->isIncompleteType() && PTy->isConstantSizeType())
+      if (getCXXABI().isTypeInfoCalculable(PTy) && PTy->isConstantSizeType())
         Attrs.addDereferenceableAttr(getContext().getTypeSizeInChars(PTy)
                                        .getQuantity());
       else if (getContext().getTargetAddressSpace(PTy) == 0)

diff --git a/clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp b/clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp
index 27a2a5f..25d7c77 100644 (file)
--- a/clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp
+++ b/clang/test/CodeGenCXX/microsoft-abi-member-pointers.cpp
@@ -745,4 +745,10 @@ void foo_fun() {
   // CHECK: store i8* bitcast (void (%class.CA*)* @"\01?OnHelp@CA@@QAEXXZ" to i8*), i8**
   f func = (f)&CA::OnHelp;
 }
+namespace PR24703 {
+struct S;
+
+void f(int S::*&p) {}
+// CHECK-LABEL: define void @"\01?f@PR24703@@YAXAAPQS@1@H@Z"(
+}