When we're emitting a diagnostic with a source location in an imported

module, provide a module import stack similar to what we would get for
an include stack, e.g.,

In module 'DependsOnModule' imported from build-fail-notes.m:4:
In module 'Module' imported from DependsOnModule.framework/Headers/DependsOnModule.h:1:
Inputs/Module.framework/Headers/Module.h:15:12: note: previous definition is here
@interface Module

<rdar://problem/12696425>


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@169042 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 20 insertions, 0 deletions

diff --git a/include/clang/Basic/SourceManager.h b/include/clang/Basic/SourceManager.h
index bd31c79ba2..d79cbfe5ae 100644
--- a/include/clang/Basic/SourceManager.h
+++ b/include/clang/Basic/SourceManager.h
@@ -430,6 +430,11 @@ public:
   /// \returns true if an error occurred that prevented the source-location
   /// entry from being loaded.
   virtual bool ReadSLocEntry(int ID) = 0;
+
+  /// \brief Retrieve the module import location and name for the given ID, if
+  /// in fact it was loaded from a module (rather than, say, a precompiled
+  /// header).
+  virtual std::pair<SourceLocation, StringRef> getModuleImportLoc(int ID) = 0;
 };
 
 
@@ -990,6 +995,21 @@ public:
     return Entry.getFile().getIncludeLoc();
   }
 
+  // \brief Returns the import location if the given source location is
+  // located within a module, or an invalid location if the source location
+  // is within the current translation unit.
+  std::pair<SourceLocation, StringRef>
+  getModuleImportLoc(SourceLocation Loc) const {
+    FileID FID = getFileID(Loc);
+
+    // Positive file IDs are in the current translation unit, and -1 is a
+    // placeholder.
+    if (FID.ID >= -1)
+      return std::make_pair(SourceLocation(), "");
+
+    return ExternalSLocEntries->getModuleImportLoc(FID.ID);
+  }
+
   /// \brief Given a SourceLocation object \p Loc, return the expansion
   /// location referenced by the ID.
   SourceLocation getExpansionLoc(SourceLocation Loc) const {