[clang-doc] Reland "[clang-doc] Setup clang-doc frontend framework"

Fixed windows release build tests.

llvm-svn: 328270
diff --git a/clang-tools-extra/clang-doc/Mapper.cpp b/clang-tools-extra/clang-doc/Mapper.cpp
new file mode 100644
index 0000000..f3ef99e
--- /dev/null
+++ b/clang-tools-extra/clang-doc/Mapper.cpp
@@ -0,0 +1,86 @@
+//===-- Mapper.cpp - ClangDoc Mapper ----------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "Mapper.h"
+#include "BitcodeWriter.h"
+#include "Serialize.h"
+#include "clang/AST/Comment.h"
+#include "clang/Index/USRGeneration.h"
+#include "llvm/ADT/StringExtras.h"
+
+using clang::comments::FullComment;
+
+namespace clang {
+namespace doc {
+
+void MapASTVisitor::HandleTranslationUnit(ASTContext &Context) {
+  TraverseDecl(Context.getTranslationUnitDecl());
+}
+
+template <typename T> bool MapASTVisitor::mapDecl(const T *D) {
+  // If we're looking a decl not in user files, skip this decl.
+  if (D->getASTContext().getSourceManager().isInSystemHeader(D->getLocation()))
+    return true;
+
+  llvm::SmallString<128> USR;
+  // If there is an error generating a USR for the decl, skip this decl.
+  if (index::generateUSRForDecl(D, USR))
+    return true;
+
+  ECtx->reportResult(llvm::toHex(llvm::toStringRef(serialize::hashUSR(USR))),
+                     serialize::emitInfo(D, getComment(D, D->getASTContext()),
+                                         getLine(D, D->getASTContext()),
+                                         getFile(D, D->getASTContext())));
+  return true;
+}
+
+bool MapASTVisitor::VisitNamespaceDecl(const NamespaceDecl *D) {
+  return mapDecl(D);
+}
+
+bool MapASTVisitor::VisitRecordDecl(const RecordDecl *D) { return mapDecl(D); }
+
+bool MapASTVisitor::VisitEnumDecl(const EnumDecl *D) { return mapDecl(D); }
+
+bool MapASTVisitor::VisitCXXMethodDecl(const CXXMethodDecl *D) {
+  return mapDecl(D);
+}
+
+bool MapASTVisitor::VisitFunctionDecl(const FunctionDecl *D) {
+  // Don't visit CXXMethodDecls twice
+  if (dyn_cast<CXXMethodDecl>(D))
+    return true;
+  return mapDecl(D);
+}
+
+comments::FullComment *
+MapASTVisitor::getComment(const NamedDecl *D, const ASTContext &Context) const {
+  RawComment *Comment = Context.getRawCommentForDeclNoCache(D);
+  // FIXME: Move setAttached to the initial comment parsing.
+  if (Comment) {
+    Comment->setAttached();
+    return Comment->parse(Context, nullptr, D);
+  }
+  return nullptr;
+}
+
+int MapASTVisitor::getLine(const NamedDecl *D,
+                           const ASTContext &Context) const {
+  return Context.getSourceManager().getPresumedLoc(D->getLocStart()).getLine();
+}
+
+llvm::StringRef MapASTVisitor::getFile(const NamedDecl *D,
+                                       const ASTContext &Context) const {
+  return Context.getSourceManager()
+      .getPresumedLoc(D->getLocStart())
+      .getFilename();
+}
+
+} // namespace doc
+} // namespace clang