DebugInfo: use uin32_t for alignment

[vleschuk]

Summary

Use uint32_t for alignment to match changes introduced in https://reviews.llvm.org/D25620

[aprantl]

include/clang/AST/ASTContext.h

83

I'm not sure we want to use a debug info type inside the AST. I think we only want to use them in CGDebugInfo.cpp.

[vleschuk]

include/clang/AST/ASTContext.h

83

We use TypeInfo and related functions heavily in CGDebugInfo.cpp, leaving this field as "unsigned" will make us to perform conversions from "unsigned" to llvm::DIAlignment, I think having this changed will result in simpler code.

[vleschuk]

include/clang/AST/ASTContext.h

83

@dblaikie wrote:

It'd still be a layering violation to have AST depend on debug info types/concepts. If it makes sense to change it to uint32_t in AST, that'd probably be reasonable.

We are discussing the possibility of changing this to "unsigned" in https://reviews.llvm.org/D25620, after we come to consensus I'll update both patches. Thanks for the advice, I agree that using DebugInfo types in AST was a bad idea.

[vleschuk]

• Use uint32_t directly for alignment instead of creating typedef ofr it
• Get rid of DebugInfo dependency in AST

[vleschuk]

Can anyone take a look at this please? =)

[aprantl]

This patch is conflating two set of changes:
(1) NFC: rename all occurrences of unsigned for alignment purposes in the frontend with uint32_t
(2) shrink all debug-info-related alignment variables from uint64_t -> unint32_t.

I think this patch should only be doing the changes in (2).

[vleschuk]

• Removed all changes non-related to CGDebugInfo: will post them in separate NFC patch which will switch all unsigned alignment entries to uint32_t.

[vleschuk]

In D25621#573671, @aprantl wrote:

This patch is conflating two set of changes:
(1) NFC: rename all occurrences of unsigned for alignment purposes in the frontend with uint32_t
(2) shrink all debug-info-related alignment variables from uint64_t -> unint32_t.

I think this patch should only be doing the changes in (2).

Agreed. Update this one. The (1) will come as separate NFC review along with corresponding LLVM patch.

[aprantl]

Thanks, this LGTM!

include/clang/AST/ASTContext.h

namespace clang {
   enum BuiltinTemplateKind : int;
 
   namespace comments {
     class FullComment;
   }
 
   struct TypeInfo {
     uint64_t Width;
-    unsigned Align;
+    llvm::DIAlignment Align;
     bool AlignIsRequired : 1;
     TypeInfo() : Width(0), Align(0), AlignIsRequired(false) {}
-    TypeInfo(uint64_t Width, unsigned Align, bool AlignIsRequired)
+    TypeInfo(uint64_t Width, llvm::DIAlignment Align, bool AlignIsRequired)
         : Width(Width), Align(Align), AlignIsRequired(AlignIsRequired) {}
   };
 
 /// \brief Holds long-lived AST nodes (such as types and decls) that can be
 /// referred to throughout the semantic analysis of a file.
 class ASTContext : public RefCountedBase<ASTContext> {
   ASTContext &this_() { return *this; }
 
public:
 
   /// \brief Return the size of the specified (complete) type \p T, in
   /// characters.
   CharUnits getTypeSizeInChars(QualType T) const;
   CharUnits getTypeSizeInChars(const Type *T) const;
 
   /// \brief Return the ABI-specified alignment of a (complete) type \p T, in
   /// bits.
-  unsigned getTypeAlign(QualType T) const { return getTypeInfo(T).Align; }
-  unsigned getTypeAlign(const Type *T) const { return getTypeInfo(T).Align; }
+  llvm::DIAlignment getTypeAlign(QualType T) const { return getTypeInfo(T).Align; }
+  llvm::DIAlignment getTypeAlign(const Type *T) const { return getTypeInfo(T).Align; }
 
   /// \brief Return the ABI-specified alignment of a type, in bits, or 0 if
   /// the type is incomplete and we cannot determine the alignment (for
   /// example, from alignment attributes).
-  unsigned getTypeAlignIfKnown(QualType T) const;
+  llvm::DIAlignment getTypeAlignIfKnown(QualType T) const;
 
   /// \brief Return the ABI-specified alignment of a (complete) type \p T, in 
   /// characters.
   CharUnits getTypeAlignInChars(QualType T) const;
   CharUnits getTypeAlignInChars(const Type *T) const;
   
   // getTypeInfoDataSizeInChars - Return the size of a type, in chars. If the
   // type is a record, its data size is returned.

include/clang/AST/DeclBase.h

 #include "clang/AST/DeclarationName.h"
 #include "clang/Basic/Specifiers.h"
 #include "clang/Basic/VersionTuple.h"
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/ADT/iterator.h"
 #include "llvm/ADT/iterator_range.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/PrettyStackTrace.h"
+#include "llvm/IR/DebugInfoMetadata.h"
 
 namespace clang {
 class ASTMutationListener;
 class BlockDecl;
 class CXXRecordDecl;
 class CompoundStmt;
 class DeclContext;
 class DeclarationName;
template<typename T> T *getAttr() const {
     return hasAttrs() ? getSpecificAttr<T>(getAttrs()) : nullptr;
   }
   template<typename T> bool hasAttr() const {
     return hasAttrs() && hasSpecificAttr<T>(getAttrs());
   }
 
   /// getMaxAlignment - return the maximum alignment specified by attributes
   /// on this decl, 0 if there are none.
-  unsigned getMaxAlignment() const;
+  llvm::DIAlignment getMaxAlignment() const;
 
   /// setInvalidDecl - Indicates the Decl had a semantic error. This
   /// allows for graceful error recovery.
   void setInvalidDecl(bool Invalid = true);
   bool isInvalidDecl() const { return (bool) InvalidDecl; }
 
   /// isImplicit - Indicates whether the declaration was implicitly
   /// generated by the implementation. If false, this declaration

lib/AST/DeclBase.cpp

 ASTContext &Decl::getASTContext() const {
   return getTranslationUnitDecl()->getASTContext();
 }
 
 ASTMutationListener *Decl::getASTMutationListener() const {
   return getASTContext().getASTMutationListener();
 }
 
-unsigned Decl::getMaxAlignment() const {
+llvm::DIAlignment Decl::getMaxAlignment() const {
   if (!hasAttrs())
     return 0;
 
-  unsigned Align = 0;
+  llvm::DIAlignment Align = 0;
   const AttrVec &V = getAttrs();
   ASTContext &Ctx = getASTContext();
   specific_attr_iterator<AlignedAttr> I(V.begin()), E(V.end());
   for (; I != E; ++I)
     Align = std::max(Align, I->getAlignment(Ctx));
   return Align;
 }
 

lib/CodeGen/CGDebugInfo.cpp

case BuiltinType::ULongLong:
     BTName = "long long unsigned int";
     break;
   default:
     BTName = BT->getName(CGM.getLangOpts());
     break;
   }
   // Bit size, align and offset of the type.
   uint64_t Size = CGM.getContext().getTypeSize(BT);
-  uint64_t Align = CGM.getContext().getTypeAlign(BT);
+  llvm::DIAlignment Align = CGM.getContext().getTypeAlign(BT);
   return DBuilder.createBasicType(BTName, Size, Align, Encoding);
 }
 
 llvm::DIType *CGDebugInfo::CreateType(const ComplexType *Ty) {
   // Bit size, align and offset of the type.
   llvm::dwarf::TypeKind Encoding = llvm::dwarf::DW_ATE_complex_float;
   if (Ty->isComplexIntegerType())
     Encoding = llvm::dwarf::DW_ATE_lo_user;
 
   uint64_t Size = CGM.getContext().getTypeSize(Ty);
-  uint64_t Align = CGM.getContext().getTypeAlign(Ty);
+  llvm::DIAlignment Align = CGM.getContext().getTypeAlign(Ty);
   return DBuilder.createBasicType("complex", Size, Align, Encoding);
 }
 
 llvm::DIType *CGDebugInfo::CreateQualifiedType(QualType Ty,
                                                llvm::DIFile *Unit) {
   QualifierCollector Qc;
   const Type *T = Qc.strip(Ty);
 
CGDebugInfo::getOrCreateRecordFwdDecl(const RecordType *Ty,
   const RecordDecl *RD = Ty->getDecl();
   if (llvm::DIType *T = getTypeOrNull(CGM.getContext().getRecordType(RD)))
     return cast<llvm::DICompositeType>(T);
   llvm::DIFile *DefUnit = getOrCreateFile(RD->getLocation());
   unsigned Line = getLineNumber(RD->getLocation());
   StringRef RDName = getClassName(RD);
 
   uint64_t Size = 0;
-  uint64_t Align = 0;
+  llvm::DIAlignment Align = 0;
 
   const RecordDecl *D = RD->getDefinition();
   if (D && D->isCompleteDefinition()) {
     Size = CGM.getContext().getTypeSize(Ty);
     Align = CGM.getContext().getTypeAlign(Ty);
   }
 
   // Create the type.
llvm::DIType *CGDebugInfo::CreatePointerLikeType(llvm::dwarf::Tag Tag,
                                                  const Type *Ty,
                                                  QualType PointeeTy,
                                                  llvm::DIFile *Unit) {
   // Bit size, align and offset of the type.
   // Size is always the size of a pointer. We can't use getTypeSize here
   // because that does not return the correct value for references.
   unsigned AS = CGM.getContext().getTargetAddressSpace(PointeeTy);
   uint64_t Size = CGM.getTarget().getPointerWidth(AS);
-  uint64_t Align = CGM.getContext().getTypeAlign(Ty);
+  llvm::DIAlignment Align = CGM.getContext().getTypeAlign(Ty);
 
   if (Tag == llvm::dwarf::DW_TAG_reference_type ||
       Tag == llvm::dwarf::DW_TAG_rvalue_reference_type)
     return DBuilder.createReferenceType(Tag, getOrCreateType(PointeeTy, Unit),
                                         Size, Align);
   else
     return DBuilder.createPointerType(getOrCreateType(PointeeTy, Unit), Size,
                                       Align);
llvm::DISubroutineType *CGDebugInfo::getOrCreateInstanceMethodType(
   // "this" pointer is always first argument.
   const CXXRecordDecl *RD = ThisPtr->getPointeeCXXRecordDecl();
   if (isa<ClassTemplateSpecializationDecl>(RD)) {
     // Create pointer type directly in this case.
     const PointerType *ThisPtrTy = cast<PointerType>(ThisPtr);
     QualType PointeeTy = ThisPtrTy->getPointeeType();
     unsigned AS = CGM.getContext().getTargetAddressSpace(PointeeTy);
     uint64_t Size = CGM.getTarget().getPointerWidth(AS);
-    uint64_t Align = CGM.getContext().getTypeAlign(ThisPtrTy);
+    llvm::DIAlignment Align = CGM.getContext().getTypeAlign(ThisPtrTy);
     llvm::DIType *PointeeType = getOrCreateType(PointeeTy, Unit);
     llvm::DIType *ThisPtrType =
         DBuilder.createPointerType(PointeeType, Size, Align);
     TypeCache[ThisPtr.getAsOpaquePtr()].reset(ThisPtrType);
     // TODO: This and the artificial type below are misleading, the
     // types aren't artificial the argument is, but the current
     // metadata doesn't represent that.
     ThisPtrType = DBuilder.createObjectPointerType(ThisPtrType);
llvm::DIType *CGDebugInfo::CreateTypeDefinition(const ObjCInterfaceType *Ty,
                                                 llvm::DIFile *Unit) {
   ObjCInterfaceDecl *ID = Ty->getDecl();
   llvm::DIFile *DefUnit = getOrCreateFile(ID->getLocation());
   unsigned Line = getLineNumber(ID->getLocation());
   unsigned RuntimeLang = TheCU->getSourceLanguage();
 
   // Bit size, align and offset of the type.
   uint64_t Size = CGM.getContext().getTypeSize(Ty);
-  uint64_t Align = CGM.getContext().getTypeAlign(Ty);
+  llvm::DIAlignment Align = CGM.getContext().getTypeAlign(Ty);
 
   llvm::DINode::DIFlags Flags = llvm::DINode::FlagZero;
   if (ID->getImplementation())
     Flags |= llvm::DINode::FlagObjcClassComplete;
  
   llvm::DIScope *Mod = getParentModuleOrNull(ID);
   llvm::DICompositeType *RealDecl = DBuilder.createStructType(
       Mod ? Mod : Unit, ID->getName(), DefUnit, Line, Size, Align, Flags,
       nullptr, llvm::DINodeArray(), RuntimeLang);
 
   QualType QTy(Ty, 0);
   TypeCache[QTy.getAsOpaquePtr()].reset(RealDecl);
 
if (Count == 0)
     // If number of elements are not known then this is an unbounded array.
     // Use Count == -1 to express such arrays.
     Count = -1;
 
   llvm::Metadata *Subscript = DBuilder.getOrCreateSubrange(0, Count);
   llvm::DINodeArray SubscriptArray = DBuilder.getOrCreateArray(Subscript);
 
   uint64_t Size = CGM.getContext().getTypeSize(Ty);
-  uint64_t Align = CGM.getContext().getTypeAlign(Ty);
+  llvm::DIAlignment Align = CGM.getContext().getTypeAlign(Ty);
 
   return DBuilder.createVectorType(Size, Align, ElementTy, SubscriptArray);
 }
 
 llvm::DIType *CGDebugInfo::CreateType(const ArrayType *Ty, llvm::DIFile *Unit) {
   uint64_t Size;
-  uint64_t Align;
+  llvm::DIAlignment Align;
 
   // FIXME: make getTypeAlign() aware of VLAs and incomplete array types
   if (const auto *VAT = dyn_cast<VariableArrayType>(Ty)) {
     Size = 0;
     Align =
         CGM.getContext().getTypeAlign(CGM.getContext().getBaseElementType(VAT));
   } else if (Ty->isIncompleteArrayType()) {
     Size = 0;
llvm::DIType* CGDebugInfo::CreateType(const PipeType *Ty,
                                      llvm::DIFile *U) {
   return getOrCreateType(Ty->getElementType(), U);
 }
 
 llvm::DIType *CGDebugInfo::CreateEnumType(const EnumType *Ty) {
   const EnumDecl *ED = Ty->getDecl();
 
   uint64_t Size = 0;
-  uint64_t Align = 0;
+  llvm::DIAlignment Align = 0;
   if (!ED->getTypeForDecl()->isIncompleteType()) {
     Size = CGM.getContext().getTypeSize(ED->getTypeForDecl());
     Align = CGM.getContext().getTypeAlign(ED->getTypeForDecl());
   }
 
   SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU);
 
   bool isImportedFromModule =
llvm::DIType *CGDebugInfo::CreateEnumType(const EnumType *Ty) {
   }
 
   return CreateTypeDefinition(Ty);
 }
 
 llvm::DIType *CGDebugInfo::CreateTypeDefinition(const EnumType *Ty) {
   const EnumDecl *ED = Ty->getDecl();
   uint64_t Size = 0;
-  uint64_t Align = 0;
+  llvm::DIAlignment Align = 0;
   if (!ED->getTypeForDecl()->isIncompleteType()) {
     Size = CGM.getContext().getTypeSize(ED->getTypeForDecl());
     Align = CGM.getContext().getTypeAlign(ED->getTypeForDecl());
   }
 
   SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU);
 
   // Create elements for each enumerator.
llvm::DICompositeType *CGDebugInfo::CreateLimitedType(const RecordType *Ty) {
 
   // If this is just a forward or incomplete declaration, construct an
   // appropriately marked node and just return it.
   const RecordDecl *D = RD->getDefinition();
   if (!D || !D->isCompleteDefinition())
     return getOrCreateRecordFwdDecl(Ty, RDContext);
 
   uint64_t Size = CGM.getContext().getTypeSize(Ty);
-  uint64_t Align = CGM.getContext().getTypeAlign(Ty);
+  llvm::DIAlignment Align = CGM.getContext().getTypeAlign(Ty);
 
   SmallString<256> FullName = getUniqueTagTypeName(Ty, CGM, TheCU);
 
   llvm::DICompositeType *RealDecl = DBuilder.createReplaceableCompositeType(
       getTagForRecord(RD), RDName, RDContext, DefUnit, Line, 0, Size, Align,
       llvm::DINode::FlagZero, FullName);
 
   // Elements of composite types usually have back to the type, creating