Frontend: Add a CC1 flag to dump module dependencies to a directory

This adds the -module-dependency-dir to clang -cc1, which specifies a
directory to copy all of a module's dependencies into in a form
suitable to be used as a VFS using -ivfsoverlay with the generated
vfs.yaml.

This is useful for crashdumps that involve modules, so that the module
dependencies will be intact when a crash report script is used to
reproduce a problem on another machine.

We currently encode the absolute path to the dump directory, due to
limitations in the VFS system. Until we can handle relative paths in
the VFS, users of the VFS map may need to run a simple search and
replace in the file.

llvm-svn: 211303

1 files changed, 22 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index e8ca0804090..03a2c229d0b 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -116,6 +116,16 @@ void CompilerInstance::setModuleManager(IntrusiveRefCntPtr<ASTReader> Reader) {
   ModuleManager = Reader;
 }
 
+std::shared_ptr<ModuleDependencyCollector>
+CompilerInstance::getModuleDepCollector() const {
+  return ModuleDepCollector;
+}
+
+void CompilerInstance::setModuleDepCollector(
+    std::shared_ptr<ModuleDependencyCollector> Collector) {
+  ModuleDepCollector = Collector;
+}
+
 // Diagnostics
 static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
                                const CodeGenOptions *CodeGenOpts,
@@ -278,6 +288,11 @@ void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
     AttachDependencyGraphGen(*PP, DepOpts.DOTOutputFile,
                              getHeaderSearchOpts().Sysroot);
 
+  // If we don't have a collector, but we are collecting module dependencies,
+  // then we're the top level compiler instance and need to create one.
+  if (!ModuleDepCollector && !DepOpts.ModuleDependencyOutputDir.empty())
+    ModuleDepCollector = std::make_shared<ModuleDependencyCollector>(
+        DepOpts.ModuleDependencyOutputDir);
 
   // Handle generating header include information, if requested.
   if (DepOpts.ShowHeaderIncludes)
@@ -851,6 +866,10 @@ static void compileModuleImpl(CompilerInstance &ImportingInstance,
   SourceMgr.pushModuleBuildStack(Module->getTopLevelModuleName(),
     FullSourceLoc(ImportLoc, ImportingInstance.getSourceManager()));
 
+  // If we're collecting module dependencies, we need to share a collector
+  // between all of the module CompilerInstances.
+  Instance.setModuleDepCollector(ImportingInstance.getModuleDepCollector());
+
   // Get or create the module map that we'll use to build this module.
   std::string InferredModuleMapContent;
   if (const FileEntry *ModuleMapFile =
@@ -1211,6 +1230,9 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
     if (TheDependencyFileGenerator)
       TheDependencyFileGenerator->AttachToASTReader(*ModuleManager);
 
+    if (ModuleDepCollector)
+      ModuleDepCollector->attachToASTReader(*ModuleManager);
+
     // Try to load the module file.
     unsigned ARRFlags = ASTReader::ARR_OutOfDate | ASTReader::ARR_Missing;
     switch (ModuleManager->ReadAST(ModuleFileName, serialization::MK_Module,