[llvm-pdbutil] Add an export subcommand.

This command can dump the binary contents of a stream to a file.
This is useful when you want to do side-by-side comparisons of
a specific stream from two PDBs to examine the differences between
them.  You can export both of them to a file, then open them up
side by side in a hex editor (for example), so as to eliminate any
differences that might arise from the contents being on different
blocks in the PDB.

In subsequent patches I plan to improve the "explain" subcommand
so that you can explain the contents of a binary file that isn't
necessarily a full PDB, but one of these dumped streams, by telling
the subcommand how to interpret the contents.

llvm-svn: 329002

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/DebugInfo/PDB/Native/InfoStream.cpp b/llvm/lib/DebugInfo/PDB/Native/InfoStream.cpp
index e9ae5a1a193..0bb543e8c64 100644
--- a/llvm/lib/DebugInfo/PDB/Native/InfoStream.cpp
+++ b/llvm/lib/DebugInfo/PDB/Native/InfoStream.cpp
@@ -86,10 +86,10 @@ Error InfoStream::reload() {
 
 uint32_t InfoStream::getStreamSize() const { return Stream->getLength(); }
 
-uint32_t InfoStream::getNamedStreamIndex(llvm::StringRef Name) const {
+Expected<uint32_t> InfoStream::getNamedStreamIndex(llvm::StringRef Name) const {
   uint32_t Result;
   if (!NamedStreams.get(Name, Result))
-    return 0;
+    return make_error<RawError>(raw_error_code::no_stream);
   return Result;
 }