Fix address space for function types with AS qualifier

[eandrews]

Summary

This patch fixes a bug introduced in commit 4eaf5846d0e7 - https://reviews.llvm.org/D111566

Commit 4eaf5846d0e7 sets address space of function type as program address space unconditionally. This breaks types which have address space qualifiers. E.g. __ptr32.

This patch fixes the bug by using address space qualifiers if present.

[aaron.ballman]

LGTM aside from some nits

clang/lib/AST/ASTContext.cpp

11962–11969

How about something like that?

clang/test/CodeGen/address-space-ptr32.c

4

[eandrews]

In D119045#3302129, @aaron.ballman wrote:

LGTM aside from some nits

Thanks! Fixed the nits in commit.

clang/lib/AST/ASTContext.cpp

if (QT->getUnqualifiedDesugaredType()->isNullPtrType())
     AS = LangAS::Default;
   else
     AS = QT->getPointeeType().getAddressSpace();
 
   return getTargetInfo().getNullPointerValue(AS);
 }
 
 unsigned ASTContext::getTargetAddressSpace(QualType T) const {
-  return T->isFunctionType() ? getTargetInfo().getProgramAddressSpace()
-                             : getTargetAddressSpace(T.getQualifiers());
+  // Return the address space for the type. If the type is a
+  // function type without an address space qualifier, the
+  // program address space is used. Otherwise, the target picks
+  // the best address space based on the type information
+  return T->isFunctionType() && !T.hasAddressSpace()
+             ? getTargetInfo().getProgramAddressSpace()
 }
 
 unsigned ASTContext::getTargetAddressSpace(Qualifiers Q) const {
   return getTargetAddressSpace(Q.getAddressSpace());
 }
 
 unsigned ASTContext::getTargetAddressSpace(LangAS AS) const {
   if (isTargetAddressSpace(AS))
     return toTargetAddressSpace(AS);

clang/test/CodeGen/address-space-ptr32.c

+// RUN: %clang_cc1 -triple x86_64-windows-msvc -fms-extensions -emit-llvm < %s | FileCheck %s
+
+int foo(void) {
+  int (*__ptr32 a)(int);
+  return sizeof(a);
+}
+
+// CHECK: define dso_local i32 @foo
+// CHECK: %a = alloca i32 (i32) addrspace(270)*, align 4
+// CHECK: ret i32 4