[CrashReproducer] Add support for merging -ivfsoverlay

Merge all VFS mapped files inside -ivfsoverlay inputs into the vfs
overlay provided by the crash reproducer. This is the last missing piece
to allow crash reproducers to fully work with user frameworks; when
combined with headermaps, it allows clang to find additional frameworks.

rdar://problem/27913709

llvm-svn: 290326

1 files changed, 21 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 5c78f81..ccddd14 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -181,6 +181,26 @@ static void collectIncludePCH(CompilerInstance &CI,
   }
 }
 
+static void collectVFSEntries(CompilerInstance &CI,
+                              std::shared_ptr<ModuleDependencyCollector> MDC) {
+  if (CI.getHeaderSearchOpts().VFSOverlayFiles.empty())
+    return;
+
+  // Collect all VFS found.
+  SmallVector<vfs::YAMLVFSEntry, 16> VFSEntries;
+  for (const std::string &VFSFile : CI.getHeaderSearchOpts().VFSOverlayFiles) {
+    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> Buffer =
+        llvm::MemoryBuffer::getFile(VFSFile);
+    if (!Buffer)
+      return;
+    vfs::collectVFSFromYAML(std::move(Buffer.get()), /*DiagHandler*/ nullptr,
+                            VFSFile, VFSEntries);
+  }
+
+  for (auto &E : VFSEntries)
+    MDC->addFile(E.VPath, E.RPath);
+}
+
 // Diagnostics
 static void SetUpDiagnosticLog(DiagnosticOptions *DiagOpts,
                                const CodeGenOptions *CodeGenOpts,
@@ -412,6 +432,7 @@ void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
     addDependencyCollector(ModuleDepCollector);
     collectHeaderMaps(PP->getHeaderSearchInfo(), ModuleDepCollector);
     collectIncludePCH(*this, ModuleDepCollector);
+    collectVFSEntries(*this, ModuleDepCollector);
   }
 
   for (auto &Listener : DependencyCollectors)