Refactor declarations of ASTContext allocate functions into its own header.

Forward declarations of the allocate functions combine with the forward
declaration of the ASTContext class is enough information for some headers
without pulling in ASTContext.h in its entirety.  Pull the existing
declarations from AttrIterator.h into a new header.  Also place the default
alignment size into this header.  Previously, new had its default in
AttrIterator.h while new[] had its default in ASTContext.h.  Add new header
includes where it is needed.  Specifically to ASTVector.h to make it a
standalone header, unlike previously which it was standalone as long as
none of its functions were called.

llvm-svn: 350792

clang/include/clang/AST/ASTContext.h

@@ -15,6 +15,7 @@
 #ifndef LLVM_CLANG_AST_ASTCONTEXT_H
 #define LLVM_CLANG_AST_ASTCONTEXT_H
 
+#include "clang/AST/ASTContextAllocate.h"
 #include "clang/AST/ASTTypeTraits.h"
 #include "clang/AST/CanonicalType.h"
 #include "clang/AST/CommentCommandTraits.h"
@@ -2969,8 +2970,8 @@ inline Selector GetUnarySelector(StringRef name, ASTContext &Ctx) {
 /// This placement form of operator new uses the ASTContext's allocator for
 /// obtaining memory.
 ///
-/// IMPORTANT: These are also declared in clang/AST/AttrIterator.h! Any changes
-/// here need to also be made there.
+/// IMPORTANT: These are also declared in clang/AST/ASTContextAllocate.h!
+/// Any changes here need to also be made there.
 ///
 /// We intentionally avoid using a nothrow specification here so that the calls
 /// to this operator will not perform a null check on the result -- the
@@ -2993,7 +2994,7 @@ inline Selector GetUnarySelector(StringRef name, ASTContext &Ctx) {
 ///                  allocator supports it).
 /// @return The allocated memory. Could be nullptr.
 inline void *operator new(size_t Bytes, const clang::ASTContext &C,
-                          size_t Alignment) {
+                          size_t Alignment /* = 8 */) {
   return C.Allocate(Bytes, Alignment);
 }
 
@@ -3031,7 +3032,7 @@ inline void operator delete(void *Ptr, const clang::ASTContext &C, size_t) {
 ///                  allocator supports it).
 /// @return The allocated memory. Could be nullptr.
 inline void *operator new[](size_t Bytes, const clang::ASTContext& C,
-                            size_t Alignment = 8) {
+                            size_t Alignment /* = 8 */) {
   return C.Allocate(Bytes, Alignment);
 }
 

clang/include/clang/AST/ASTContextAllocate.h

@@ -0,0 +1,38 @@
+//===- ASTContextAllocate.h - ASTContext allocate functions -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file declares ASTContext allocation functions separate from the main
+//  code in ASTContext.h.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_AST_ASTCONTEXTALLOCATE_H
+#define LLVM_CLANG_AST_ASTCONTEXTALLOCATE_H
+
+#include <cstddef>
+
+namespace clang {
+
+class ASTContext;
+
+} // namespace clang
+
+// Defined in ASTContext.h
+void *operator new(size_t Bytes, const clang::ASTContext &C,
+                   size_t Alignment = 8);
+void *operator new[](size_t Bytes, const clang::ASTContext &C,
+                     size_t Alignment = 8);
+
+// It is good practice to pair new/delete operators.  Also, MSVC gives many
+// warnings if a matching delete overload is not declared, even though the
+// throw() spec guarantees it will not be implicitly called.
+void operator delete(void *Ptr, const clang::ASTContext &C, size_t);
+void operator delete[](void *Ptr, const clang::ASTContext &C, size_t);
+
+#endif // LLVM_CLANG_AST_ASTCONTEXTALLOCATE_H

clang/include/clang/AST/ASTVector.h

@@ -18,6 +18,7 @@
 #ifndef LLVM_CLANG_AST_ASTVECTOR_H
 #define LLVM_CLANG_AST_ASTVECTOR_H
 
+#include "clang/AST/ASTContextAllocate.h"
 #include "llvm/ADT/PointerIntPair.h"
 #include <algorithm>
 #include <cassert>

clang/include/clang/AST/Attr.h

@@ -14,6 +14,7 @@
 #ifndef LLVM_CLANG_AST_ATTR_H
 #define LLVM_CLANG_AST_ATTR_H
 
+#include "clang/AST/ASTContextAllocate.h"  // For Attrs.inc
 #include "clang/AST/AttrIterator.h"
 #include "clang/AST/Decl.h"
 #include "clang/AST/Expr.h"

clang/include/clang/AST/AttrIterator.h

@@ -26,25 +26,6 @@ namespace clang {
 class ASTContext;
 class Attr;
 
-} // namespace clang
-
-// Defined in ASTContext.h
-void *operator new(size_t Bytes, const clang::ASTContext &C,
-                   size_t Alignment = 8);
-
-// FIXME: Being forced to not have a default argument here due to redeclaration
-//        rules on default arguments sucks
-void *operator new[](size_t Bytes, const clang::ASTContext &C,
-                     size_t Alignment);
-
-// It is good practice to pair new/delete operators.  Also, MSVC gives many
-// warnings if a matching delete overload is not declared, even though the
-// throw() spec guarantees it will not be implicitly called.
-void operator delete(void *Ptr, const clang::ASTContext &C, size_t);
-void operator delete[](void *Ptr, const clang::ASTContext &C, size_t);
-
-namespace clang {
-
 /// AttrVec - A vector of Attr, which is how they are stored on the AST.
 using AttrVec = SmallVector<Attr *, 4>;
 

clang/include/clang/AST/Decl.h

@@ -15,6 +15,7 @@
 #define LLVM_CLANG_AST_DECL_H
 
 #include "clang/AST/APValue.h"
+#include "clang/AST/ASTContextAllocate.h"
 #include "clang/AST/DeclBase.h"
 #include "clang/AST/DeclarationName.h"
 #include "clang/AST/ExternalASTSource.h"