Wrap clang module files in a Mach-O, ELF, or COFF container.

This is a necessary prerequisite for debugging with modules.
The .pcm files become containers that hold the serialized AST which allows
us to store debug information in the module file that can be shared by all
object files that were built importing the module.

rdar://problem/19104245

llvm-svn: 230044

1 files changed, 10 insertions, 6 deletions

diff --git a/clang/lib/Frontend/ChainedIncludesSource.cpp b/clang/lib/Frontend/ChainedIncludesSource.cpp
index cb260b4f4c6..1ecc0bfc6b4 100644
--- a/clang/lib/Frontend/ChainedIncludesSource.cpp
+++ b/clang/lib/Frontend/ChainedIncludesSource.cpp
@@ -156,11 +156,13 @@ IntrusiveRefCntPtr<ExternalSemaSource> clang::createChainedIncludesSource(
                                                  &Clang->getPreprocessor());
     Clang->createASTContext();
 
-    SmallVector<char, 256> serialAST;
-    llvm::raw_svector_ostream OS(serialAST);
-    auto consumer =
-        llvm::make_unique<PCHGenerator>(Clang->getPreprocessor(), "-", nullptr,
-                                        /*isysroot=*/"", &OS);
+    auto consumer = llvm::make_unique<PCHGenerator>(Clang->getPreprocessor(),
+                                       "-", nullptr, /*isysroot=*/"");
+    SmallVectorImpl<char> *serialAST;
+    consumer->RegisterSerializationFinishedCallback(
+      [&](SmallVectorImpl<char> *Buf){
+        serialAST = Buf;
+      });
     Clang->getASTContext().setASTMutationListener(
                                             consumer->GetASTMutationListener());
     Clang->setASTConsumer(std::move(consumer));
@@ -197,7 +199,9 @@ IntrusiveRefCntPtr<ExternalSemaSource> clang::createChainedIncludesSource(
 
     ParseAST(Clang->getSema());
     Clang->getDiagnosticClient().EndSourceFile();
-    SerialBufs.push_back(llvm::MemoryBuffer::getMemBufferCopy(OS.str()));
+    SerialBufs.push_back(llvm::MemoryBuffer::
+        getMemBufferCopy(StringRef(serialAST->data(), serialAST->size())));
+    serialAST->clear();
     source->CIs.push_back(Clang.release());
   }