[CodeView] Handle Cross Module Imports and Exports.

While it's not entirely clear why a compiler or linker might
put this information into an object or PDB file, one has been
spotted in the wild which was causing llvm-pdbdump to crash.

This patch adds support for reading-writing these sections.
Since I don't know how to get one of the native tools to
generate this kind of debug info, the only test here is one
in which we feed YAML into the tool to produce a PDB and
then spit out YAML from the resulting PDB and make sure that
it matches.

llvm-svn: 304738

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/DebugInfo/PDB/Native/ModuleDebugStream.cpp b/llvm/lib/DebugInfo/PDB/Native/ModuleDebugStream.cpp
index c4ff30011a1..4186f2eb6ba 100644
--- a/llvm/lib/DebugInfo/PDB/Native/ModuleDebugStream.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/ModuleDebugStream.cpp
@@ -90,14 +90,14 @@ Error ModuleDebugStreamRef::commit() { return Error::success(); }
 
 Expected<codeview::DebugChecksumsSubsectionRef>
 ModuleDebugStreamRef::findChecksumsSubsection() const {
+  codeview::DebugChecksumsSubsectionRef Result;
   for (const auto &SS : subsections()) {
     if (SS.kind() != DebugSubsectionKind::FileChecksums)
       continue;
 
-    codeview::DebugChecksumsSubsectionRef Result;
     if (auto EC = Result.initialize(SS.getRecordData()))
       return std::move(EC);
     return Result;
   }
-  return make_error<RawError>(raw_error_code::no_entry);
+  return Result;
 }