[Sema] Fix Modified Type in address_space AttributedType

This is a fix for https://reviews.llvm.org/D51229 where we pass the
address_space qualified type as the modified type of an AttributedType. This
change now instead wraps the AttributedType with either the address_space
qualifier or a DependentAddressSpaceType.

Differential Revision: https://reviews.llvm.org/D55447

llvm-svn: 351997

3 files changed, 83 insertions, 28 deletions

diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index ebbf105d98f..452ff6201a2 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -3205,6 +3205,7 @@ bool AttributedType::isQualifier() const {
   case attr::TypeNullable:
   case attr::TypeNullUnspecified:
   case attr::LifetimeBound:
+  case attr::AddressSpace:
     return true;
 
   // All other type attributes aren't qualifiers; they rewrite the modified
diff --git a/clang/lib/AST/TypePrinter.cpp b/clang/lib/AST/TypePrinter.cpp
index 11f9ec33e94..a98b45bebd3 100644
--- a/clang/lib/AST/TypePrinter.cpp
+++ b/clang/lib/AST/TypePrinter.cpp
@@ -257,11 +257,17 @@ bool TypePrinter::canPrefixQualifiers(const Type *T,
     case Type::FunctionProto:
     case Type::FunctionNoProto:
     case Type::Paren:
-    case Type::Attributed:
     case Type::PackExpansion:
     case Type::SubstTemplateTypeParm:
       CanPrefixQualifiers = false;
       break;
+
+    case Type::Attributed: {
+      // We still want to print the address_space before the type if it is an
+      // address_space attribute.
+      const auto *AttrTy = cast<AttributedType>(T);
+      CanPrefixQualifiers = AttrTy->getAttrKind() == attr::AddressSpace;
+    }
   }
 
   return CanPrefixQualifiers;
@@ -1377,7 +1383,10 @@ void TypePrinter::printAttributedBefore(const AttributedType *T,
   if (T->getAttrKind() == attr::ObjCKindOf)
     OS << "__kindof ";
 
-  printBefore(T->getModifiedType(), OS);
+  if (T->getAttrKind() == attr::AddressSpace)
+    printBefore(T->getEquivalentType(), OS);
+  else
+    printBefore(T->getModifiedType(), OS);
 
   if (T->isMSTypeSpec()) {
     switch (T->getAttrKind()) {
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 93b42829bba..b1aac72ea50 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -5787,28 +5787,27 @@ ParsedType Sema::ActOnObjCInstanceType(SourceLocation Loc) {
 // Type Attribute Processing
 //===----------------------------------------------------------------------===//
 
-/// BuildAddressSpaceAttr - Builds a DependentAddressSpaceType if an expression
-/// is uninstantiated. If instantiated it will apply the appropriate address space
-/// to the type. This function allows dependent template variables to be used in
-/// conjunction with the address_space attribute
-QualType Sema::BuildAddressSpaceAttr(QualType &T, Expr *AddrSpace,
-                                     SourceLocation AttrLoc) {
+/// Build an AddressSpace index from a constant expression and diagnose any
+/// errors related to invalid address_spaces. Returns true on successfully
+/// building an AddressSpace index.
+static bool BuildAddressSpaceIndex(Sema &S, LangAS &ASIdx,
+                                   const Expr *AddrSpace,
+                                   SourceLocation AttrLoc) {
   if (!AddrSpace->isValueDependent()) {
-
     llvm::APSInt addrSpace(32);
-    if (!AddrSpace->isIntegerConstantExpr(addrSpace, Context)) {
-      Diag(AttrLoc, diag::err_attribute_argument_type)
+    if (!AddrSpace->isIntegerConstantExpr(addrSpace, S.Context)) {
+      S.Diag(AttrLoc, diag::err_attribute_argument_type)
           << "'address_space'" << AANT_ArgumentIntegerConstant
           << AddrSpace->getSourceRange();
-      return QualType();
+      return false;
     }
 
     // Bounds checking.
     if (addrSpace.isSigned()) {
       if (addrSpace.isNegative()) {
-        Diag(AttrLoc, diag::err_attribute_address_space_negative)
+        S.Diag(AttrLoc, diag::err_attribute_address_space_negative)
             << AddrSpace->getSourceRange();
-        return QualType();
+        return false;
       }
       addrSpace.setIsSigned(false);
     }
@@ -5817,14 +5816,28 @@ QualType Sema::BuildAddressSpaceAttr(QualType &T, Expr *AddrSpace,
     max =
         Qualifiers::MaxAddressSpace - (unsigned)LangAS::FirstTargetAddressSpace;
     if (addrSpace > max) {
-      Diag(AttrLoc, diag::err_attribute_address_space_too_high)
+      S.Diag(AttrLoc, diag::err_attribute_address_space_too_high)
           << (unsigned)max.getZExtValue() << AddrSpace->getSourceRange();
-      return QualType();
+      return false;
     }
 
-    LangAS ASIdx =
+    ASIdx =
         getLangASFromTargetAS(static_cast<unsigned>(addrSpace.getZExtValue()));
+    return true;
+  }
 
+  // Default value for DependentAddressSpaceTypes
+  ASIdx = LangAS::Default;
+  return true;
+}
+
+/// BuildAddressSpaceAttr - Builds a DependentAddressSpaceType if an expression
+/// is uninstantiated. If instantiated it will apply the appropriate address
+/// space to the type. This function allows dependent template variables to be
+/// used in conjunction with the address_space attribute
+QualType Sema::BuildAddressSpaceAttr(QualType &T, LangAS ASIdx, Expr *AddrSpace,
+                                     SourceLocation AttrLoc) {
+  if (!AddrSpace->isValueDependent()) {
     if (DiagnoseMultipleAddrSpaceAttributes(*this, T.getAddressSpace(), ASIdx,
                                             AttrLoc))
       return QualType();
@@ -5845,6 +5858,14 @@ QualType Sema::BuildAddressSpaceAttr(QualType &T, Expr *AddrSpace,
   return Context.getDependentAddressSpaceType(T, AddrSpace, AttrLoc);
 }
 
+QualType Sema::BuildAddressSpaceAttr(QualType &T, Expr *AddrSpace,
+                                     SourceLocation AttrLoc) {
+  LangAS ASIdx;
+  if (!BuildAddressSpaceIndex(*this, ASIdx, AddrSpace, AttrLoc))
+    return QualType();
+  return BuildAddressSpaceAttr(T, ASIdx, AddrSpace, AttrLoc);
+}
+
 /// HandleAddressSpaceTypeAttribute - Process an address_space attribute on the
 /// specified type.  The attribute contains 1 argument, the id of the address
 /// space for the type.
@@ -5890,19 +5911,41 @@ static void HandleAddressSpaceTypeAttribute(QualType &Type,
       ASArgExpr = static_cast<Expr *>(Attr.getArgAsExpr(0));
     }
 
-    // Create the DependentAddressSpaceType or append an address space onto
-    // the type.
-    QualType T = S.BuildAddressSpaceAttr(Type, ASArgExpr, Attr.getLoc());
+    LangAS ASIdx;
+    if (!BuildAddressSpaceIndex(S, ASIdx, ASArgExpr, Attr.getLoc())) {
+      Attr.setInvalid();
+      return;
+    }
 
-    if (!T.isNull()) {
-      ASTContext &Ctx = S.Context;
-      auto *ASAttr = ::new (Ctx) AddressSpaceAttr(
-          Attr.getRange(), Ctx, Attr.getAttributeSpellingListIndex(),
-          static_cast<unsigned>(T.getQualifiers().getAddressSpace()));
-      Type = State.getAttributedType(ASAttr, T, T);
+    ASTContext &Ctx = S.Context;
+    auto *ASAttr = ::new (Ctx) AddressSpaceAttr(
+        Attr.getRange(), Ctx, Attr.getAttributeSpellingListIndex(),
+        static_cast<unsigned>(ASIdx));
+
+    // If the expression is not value dependent (not templated), then we can
+    // apply the address space qualifiers just to the equivalent type.
+    // Otherwise, we make an AttributedType with the modified and equivalent
+    // type the same, and wrap it in a DependentAddressSpaceType. When this
+    // dependent type is resolved, the qualifier is added to the equivalent type
+    // later.
+    QualType T;
+    if (!ASArgExpr->isValueDependent()) {
+      QualType EquivType =
+          S.BuildAddressSpaceAttr(Type, ASIdx, ASArgExpr, Attr.getLoc());
+      if (EquivType.isNull()) {
+        Attr.setInvalid();
+        return;
+      }
+      T = State.getAttributedType(ASAttr, Type, EquivType);
     } else {
-      Attr.setInvalid();
+      T = State.getAttributedType(ASAttr, Type, Type);
+      T = S.BuildAddressSpaceAttr(T, ASIdx, ASArgExpr, Attr.getLoc());
     }
+
+    if (!T.isNull())
+      Type = T;
+    else
+      Attr.setInvalid();
   } else {
     // The keyword-based type attributes imply which address space to use.
     ASIdx = Attr.asOpenCLLangAS();
@@ -7346,9 +7389,11 @@ static void processTypeAttrs(TypeProcessingState &state, QualType &type,
           if (!IsTypeAttr)
             continue;
         }
-      } else if (TAL != TAL_DeclChunk) {
+      } else if (TAL != TAL_DeclChunk &&
+                 attr.getKind() != ParsedAttr::AT_AddressSpace) {
         // Otherwise, only consider type processing for a C++11 attribute if
         // it's actually been applied to a type.
+        // We also allow C++11 address_space attributes to pass through.
         continue;
       }
     }