[libclang] When logging a CXTranslationUnit that came from an AST file, print out the filename.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176511 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Frontend/ASTUnit.h b/include/clang/Frontend/ASTUnit.h
index 9a02c0c..108114d 100644
--- a/include/clang/Frontend/ASTUnit.h
+++ b/include/clang/Frontend/ASTUnit.h
@@ -485,6 +485,9 @@
 
   StringRef getMainFileName() const;
 
+  /// \brief If this ASTUnit came from an AST file, returns the filename for it.
+  StringRef getASTFileName() const;
+
   typedef std::vector<Decl *>::iterator top_level_iterator;
 
   top_level_iterator top_level_begin() {
diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index 3dc6e2e..4a956ff 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -1711,6 +1711,15 @@
   return StringRef();
 }
 
+StringRef ASTUnit::getASTFileName() const {
+  if (!isMainFileAST())
+    return StringRef();
+
+  serialization::ModuleFile &
+    Mod = Reader->getModuleManager().getPrimaryModule();
+  return Mod.FileName;
+}
+
 ASTUnit *ASTUnit::create(CompilerInvocation *CI,
                          IntrusiveRefCntPtr<DiagnosticsEngine> Diags,
                          bool CaptureDiagnostics,
diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index 36224a8..2cfaea4 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -6387,6 +6387,8 @@
   if (TU) {
     if (ASTUnit *Unit = cxtu::getASTUnit(TU)) {
       LogOS << '<' << Unit->getMainFileName() << '>';
+      if (Unit->isMainFileAST())
+        LogOS << " (" << Unit->getASTFileName() << ')';
       return *this;
     }
   }