| //===--- TypeLocBuilder.h - Type Source Info collector ----------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This files defines TypeLocBuilder, a class for building TypeLocs |
| // bottom-up. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef LLVM_CLANG_SEMA_TYPELOCBUILDER_H |
| #define LLVM_CLANG_SEMA_TYPELOCBUILDER_H |
| |
| #include "clang/AST/TypeLoc.h" |
| #include "clang/AST/ASTContext.h" |
| |
| namespace clang { |
| |
| class TypeLocBuilder { |
| enum { InlineCapacity = 8 * sizeof(SourceLocation) }; |
| |
| /// The underlying location-data buffer. Data grows from the end |
| /// of the buffer backwards. |
| char *Buffer; |
| |
| /// The capacity of the current buffer. |
| size_t Capacity; |
| |
| /// The index of the first occupied byte in the buffer. |
| size_t Index; |
| |
| #ifndef NDEBUG |
| /// The last type pushed on this builder. |
| QualType LastTy; |
| #endif |
| |
| /// The inline buffer. |
| char InlineBuffer[InlineCapacity]; |
| |
| public: |
| TypeLocBuilder() |
| : Buffer(InlineBuffer), Capacity(InlineCapacity), Index(InlineCapacity) {} |
| |
| ~TypeLocBuilder() { |
| if (Buffer != InlineBuffer) |
| delete[] Buffer; |
| } |
| |
| /// Ensures that this buffer has at least as much capacity as described. |
| void reserve(size_t Requested) { |
| if (Requested > Capacity) |
| // For now, match the request exactly. |
| grow(Requested); |
| } |
| |
| /// Pushes a copy of the given TypeLoc onto this builder. The builder |
| /// must be empty for this to work. |
| void pushFullCopy(TypeLoc L) { |
| size_t Size = L.getFullDataSize(); |
| TypeLoc Copy = pushFullUninitializedImpl(L.getType(), Size); |
| memcpy(Copy.getOpaqueData(), L.getOpaqueData(), Size); |
| } |
| |
| /// Pushes uninitialized space for the given type. The builder must |
| /// be empty. |
| TypeLoc pushFullUninitialized(QualType T) { |
| return pushFullUninitializedImpl(T, TypeLoc::getFullDataSizeForType(T)); |
| } |
| |
| /// Pushes space for a typespec TypeLoc. Invalidates any TypeLocs |
| /// previously retrieved from this builder. |
| TypeSpecTypeLoc pushTypeSpec(QualType T) { |
| size_t LocalSize = TypeSpecTypeLoc::LocalDataSize; |
| return cast<TypeSpecTypeLoc>(pushImpl(T, LocalSize)); |
| } |
| |
| /// Resets this builder to the newly-initialized state. |
| void clear() { |
| #ifndef NDEBUG |
| LastTy = QualType(); |
| #endif |
| Index = Capacity; |
| } |
| |
| /// \brief Tell the TypeLocBuilder that the type it is storing has been |
| /// modified in some safe way that doesn't affect type-location information. |
| void TypeWasModifiedSafely(QualType T) { |
| #ifndef NDEBUG |
| LastTy = T; |
| #endif |
| } |
| |
| /// Pushes space for a new TypeLoc of the given type. Invalidates |
| /// any TypeLocs previously retrieved from this builder. |
| template <class TyLocType> TyLocType push(QualType T) { |
| size_t LocalSize = cast<TyLocType>(TypeLoc(T, 0)).getLocalDataSize(); |
| return cast<TyLocType>(pushImpl(T, LocalSize)); |
| } |
| |
| /// Creates a TypeSourceInfo for the given type. |
| TypeSourceInfo *getTypeSourceInfo(ASTContext& Context, QualType T) { |
| #ifndef NDEBUG |
| assert(T == LastTy && "type doesn't match last type pushed!"); |
| #endif |
| |
| size_t FullDataSize = Capacity - Index; |
| TypeSourceInfo *DI = Context.CreateTypeSourceInfo(T, FullDataSize); |
| memcpy(DI->getTypeLoc().getOpaqueData(), &Buffer[Index], FullDataSize); |
| return DI; |
| } |
| |
| /// \brief Copies the type-location information to the given AST context and |
| /// returns a \c TypeLoc referring into the AST context. |
| TypeLoc getTypeLocInContext(ASTContext &Context, QualType T) { |
| #ifndef NDEBUG |
| assert(T == LastTy && "type doesn't match last type pushed!"); |
| #endif |
| |
| size_t FullDataSize = Capacity - Index; |
| void *Mem = Context.Allocate(FullDataSize); |
| memcpy(Mem, &Buffer[Index], FullDataSize); |
| return TypeLoc(T, Mem); |
| } |
| |
| private: |
| TypeLoc pushImpl(QualType T, size_t LocalSize) { |
| #ifndef NDEBUG |
| QualType TLast = TypeLoc(T, 0).getNextTypeLoc().getType(); |
| assert(TLast == LastTy && |
| "mismatch between last type and new type's inner type"); |
| LastTy = T; |
| #endif |
| |
| // If we need to grow, grow by a factor of 2. |
| if (LocalSize > Index) { |
| size_t RequiredCapacity = Capacity + (LocalSize - Index); |
| size_t NewCapacity = Capacity * 2; |
| while (RequiredCapacity > NewCapacity) |
| NewCapacity *= 2; |
| grow(NewCapacity); |
| } |
| |
| Index -= LocalSize; |
| |
| return getTemporaryTypeLoc(T); |
| } |
| |
| /// Grow to the given capacity. |
| void grow(size_t NewCapacity) { |
| assert(NewCapacity > Capacity); |
| |
| // Allocate the new buffer and copy the old data into it. |
| char *NewBuffer = new char[NewCapacity]; |
| unsigned NewIndex = Index + NewCapacity - Capacity; |
| memcpy(&NewBuffer[NewIndex], |
| &Buffer[Index], |
| Capacity - Index); |
| |
| if (Buffer != InlineBuffer) |
| delete[] Buffer; |
| |
| Buffer = NewBuffer; |
| Capacity = NewCapacity; |
| Index = NewIndex; |
| } |
| |
| TypeLoc pushFullUninitializedImpl(QualType T, size_t Size) { |
| #ifndef NDEBUG |
| assert(LastTy.isNull() && "pushing full on non-empty TypeLocBuilder"); |
| LastTy = T; |
| #endif |
| assert(Index == Capacity && "pushing full on non-empty TypeLocBuilder"); |
| |
| reserve(Size); |
| Index -= Size; |
| |
| return getTemporaryTypeLoc(T); |
| } |
| |
| public: |
| /// \brief Retrieve a temporary TypeLoc that refers into this \c TypeLocBuilder |
| /// object. |
| /// |
| /// The resulting \c TypeLoc should only be used so long as the |
| /// \c TypeLocBuilder is active and has not had more type information |
| /// pushed into it. |
| TypeLoc getTemporaryTypeLoc(QualType T) { |
| #ifndef NDEBUG |
| assert(LastTy == T && "type doesn't match last type pushed!"); |
| #endif |
| return TypeLoc(T, &Buffer[Index]); |
| } |
| }; |
| |
| } |
| |
| #endif |