When an error occurs while building a module on demand, provide "While

building module 'Foo' imported from..." notes (the same we we provide
"In file included from..." notes) in the diagnostic, so that we know
how this module got included in the first place. This is part of
<rdar://problem/12696425>.

llvm-svn: 169021

1 files changed, 25 insertions, 14 deletions

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index f87a6354205..150f99578c4 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -762,6 +762,7 @@ static void doCompileMapModule(void *UserData) {
 /// \brief Compile a module file for the given module, using the options 
 /// provided by the importing compiler instance.
 static void compileModule(CompilerInstance &ImportingInstance,
+                          SourceLocation ImportLoc,
                           Module *Module,
                           StringRef ModuleFileName) {
   llvm::LockFileManager Locked(ModuleFileName);
@@ -797,10 +798,6 @@ static void compileModule(CompilerInstance &ImportingInstance,
   // Note the name of the module we're building.
   Invocation->getLangOpts()->CurrentModule = Module->getTopLevelModuleName();
 
-  // Note that this module is part of the module build path, so that we
-  // can detect cycles in the module graph.
-  PPOpts.ModuleBuildPath.push_back(Module->getTopLevelModuleName());
-
   // Make sure that the failed-module structure has been allocated in
   // the importing instance, and propagate the pointer to the newly-created
   // instance.
@@ -861,7 +858,18 @@ static void compileModule(CompilerInstance &ImportingInstance,
                              &ImportingInstance.getDiagnosticClient(),
                              /*ShouldOwnClient=*/true,
                              /*ShouldCloneClient=*/true);
-  
+
+  // Note that this module is part of the module build path, so that we
+  // can detect cycles in the module graph.
+  Instance.createFileManager(); // FIXME: Adopt file manager from importer?
+  Instance.createSourceManager(Instance.getFileManager());
+  SourceManager &SourceMgr = Instance.getSourceManager();
+  SourceMgr.setModuleBuildPath(
+    ImportingInstance.getSourceManager().getModuleBuildPath());
+  SourceMgr.appendModuleBuildPath(Module->getTopLevelModuleName(),
+    FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
+
+
   // Construct a module-generating action.
   GenerateModuleAction CreateModuleAction;
   
@@ -939,14 +947,17 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
       // build the module.
 
       // Check whether there is a cycle in the module graph.
-      SmallVectorImpl<std::string> &ModuleBuildPath
-        = getPreprocessorOpts().ModuleBuildPath;
-      SmallVectorImpl<std::string>::iterator Pos
-        = std::find(ModuleBuildPath.begin(), ModuleBuildPath.end(), ModuleName);
-      if (Pos != ModuleBuildPath.end()) {
+      ModuleBuildPath Path = getSourceManager().getModuleBuildPath();
+      ModuleBuildPath::iterator Pos = Path.begin(), PosEnd = Path.end();
+      for (; Pos != PosEnd; ++Pos) {
+        if (Pos->first == ModuleName)
+          break;
+      }
+
+      if (Pos != PosEnd) {
         SmallString<256> CyclePath;
-        for (; Pos != ModuleBuildPath.end(); ++Pos) {
-          CyclePath += *Pos;
+        for (; Pos != PosEnd; ++Pos) {
+          CyclePath += Pos->first;
           CyclePath += " -> ";
         }
         CyclePath += ModuleName;
@@ -970,7 +981,7 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
       getDiagnostics().Report(ModuleNameLoc, diag::warn_module_build)
         << ModuleName;
       BuildingModule = true;
-      compileModule(*this, Module, ModuleFileName);
+      compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
       ModuleFile = FileMgr->getFile(ModuleFileName);
 
       if (!ModuleFile)
@@ -1040,7 +1051,7 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
         return ModuleLoadResult();
       }
 
-      compileModule(*this, Module, ModuleFileName);
+      compileModule(*this, ModuleNameLoc, Module, ModuleFileName);
 
       // Try loading the module again.
       ModuleFile = FileMgr->getFile(ModuleFileName);