[CrossTU] Add a function to retrieve original source location.

Summary:
A new function will be added to get the original SourceLocation
for a SourceLocation that was imported as result of getCrossTUDefinition.
The returned SourceLocation is in the context of the (original)
SourceManager for the original source file. Additionally the
ASTUnit object for that source file is returned. This is needed
to get a SourceManager to operate on with the returned source location.

The new function works if multiple different source files are loaded
with the same CrossTU context.

This patch can be treated as part of a bigger change that is needed to
improve macro expansion handliong at plist generation.

Reviewers: martong, shafik, a_sidorin, xazax.hun

Reviewed By: martong

Subscribers: rnkovacs, dkrupp, Szelethus, gamesh411, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D64554

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@366449 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 16 insertions, 4 deletions

diff --git a/include/clang/CrossTU/CrossTranslationUnit.h b/include/clang/CrossTU/CrossTranslationUnit.h
index d64329cdff..7b689bdf33 100644
--- a/include/clang/CrossTU/CrossTranslationUnit.h
+++ b/include/clang/CrossTU/CrossTranslationUnit.h
@@ -153,8 +153,10 @@ public:
   ///        was passed to the constructor.
   ///
   /// \return Returns the resulting definition or an error.
-  llvm::Expected<const FunctionDecl *> importDefinition(const FunctionDecl *FD);
-  llvm::Expected<const VarDecl *> importDefinition(const VarDecl *VD);
+  llvm::Expected<const FunctionDecl *> importDefinition(const FunctionDecl *FD,
+                                                        ASTUnit *Unit);
+  llvm::Expected<const VarDecl *> importDefinition(const VarDecl *VD,
+                                                   ASTUnit *Unit);
 
   /// Get a name to identify a named decl.
   static std::string getLookupName(const NamedDecl *ND);
@@ -162,9 +164,19 @@ public:
   /// Emit diagnostics for the user for potential configuration errors.
   void emitCrossTUDiagnostics(const IndexError &IE);
 
+  /// Determine the original source location in the original TU for an
+  /// imported source location.
+  /// \p ToLoc Source location in the imported-to AST.
+  /// \return Source location in the imported-from AST and the corresponding
+  /// ASTUnit.
+  /// If any error happens (ToLoc is a non-imported source location) empty is
+  /// returned.
+  llvm::Optional<std::pair<SourceLocation /*FromLoc*/, ASTUnit *>>
+  getImportedFromSourceLocation(const clang::SourceLocation &ToLoc) const;
+
 private:
   void lazyInitImporterSharedSt(TranslationUnitDecl *ToTU);
-  ASTImporter &getOrCreateASTImporter(ASTContext &From);
+  ASTImporter &getOrCreateASTImporter(ASTUnit *Unit);
   template <typename T>
   llvm::Expected<const T *> getCrossTUDefinitionImpl(const T *D,
                                                      StringRef CrossTUDir,
@@ -174,7 +186,7 @@ private:
   const T *findDefInDeclContext(const DeclContext *DC,
                                 StringRef LookupName);
   template <typename T>
-  llvm::Expected<const T *> importDefinitionImpl(const T *D);
+  llvm::Expected<const T *> importDefinitionImpl(const T *D, ASTUnit *Unit);
 
   llvm::StringMap<std::unique_ptr<clang::ASTUnit>> FileASTUnitMap;
   llvm::StringMap<clang::ASTUnit *> NameASTUnitMap;