Make TypeLocBuilder an implementation detail of Sema. Nobody else should be using it

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@120628 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 181 insertions, 1 deletions

diff --git a/lib/Sema/TreeTransform.h b/lib/Sema/TreeTransform.h
index 807346c4c5..5aea3f029d 100644
--- a/lib/Sema/TreeTransform.h
+++ b/lib/Sema/TreeTransform.h
@@ -25,11 +25,11 @@
 #include "clang/AST/Stmt.h"
 #include "clang/AST/StmtCXX.h"
 #include "clang/AST/StmtObjC.h"
-#include "clang/AST/TypeLocBuilder.h"
 #include "clang/Sema/Ownership.h"
 #include "clang/Sema/Designator.h"
 #include "clang/Lex/Preprocessor.h"
 #include "llvm/Support/ErrorHandling.h"
+#include "TypeLocBuilder.h"
 #include <algorithm>
 
 namespace clang {
diff --git a/lib/Sema/TypeLocBuilder.h b/lib/Sema/TypeLocBuilder.h
new file mode 100644
index 0000000000..3d20a5273d
--- /dev/null
+++ b/lib/Sema/TypeLocBuilder.h
@@ -0,0 +1,180 @@
+//===--- 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 "llvm/ADT/SmallVector.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;
+  }  
+
+  /// 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;
+  }
+
+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 getTypeLoc(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 getTypeLoc(T);
+  }
+
+
+  // This is private because, when we kill off TypeSourceInfo in favor
+  // of TypeLoc, we'll want an interface that creates a TypeLoc given
+  // an ASTContext, and we don't want people to think they can just
+  // use this as an equivalent.
+  TypeLoc getTypeLoc(QualType T) {
+#ifndef NDEBUG
+    assert(LastTy == T && "type doesn't match last type pushed!");
+#endif
+    return TypeLoc(T, &Buffer[Index]);
+  }
+};
+
+}
+
+#endif