Enable ability to have multiple PNaCl wire format versions.

Modifies PNaCl bitcode reader/writer to accept PNaClVersion=1 as supported,
and all other versions are unsupported and unreadable. The PNaCl bitcode
reader/writer will generate appropriate messages (including what version
is unsupported if applicable).

Also allows command-line option --pnacl-version for setting the PNaClVersion
in the PNaCl bitcode writer.

Also fixes some problems on PNaCl bitcode headers, using common support to
determine when the read/written PNaCl bitcode file is valid.

BUG=None
R=jvoung@chromium.org

Review URL: https://codereview.chromium.org/19400002

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/Bitcode/NaCl/Reader/NaClBitcodeHeader.cpp b/lib/Bitcode/NaCl/Reader/NaClBitcodeHeader.cpp
index aa73b9cffa..2dd2af5dc3 100644
--- a/lib/Bitcode/NaCl/Reader/NaClBitcodeHeader.cpp
+++ b/lib/Bitcode/NaCl/Reader/NaClBitcodeHeader.cpp
@@ -249,8 +249,12 @@ void NaClBitcodeHeader::InstallFields() {
   if (PNaClVersion != 1) {
     IsSupportedFlag = false;
     IsReadableFlag = false;
-    UnsupportedMessage = "Unsupported Version";
     UpdatedUnsupportedMessage = true;
+    UnsupportedMessage.clear();
+    raw_string_ostream UnsupportedStream(UnsupportedMessage);
+    UnsupportedStream << "Unsupported PNaCl bitcode version: "
+                      << PNaClVersion << "\n";
+    UnsupportedStream.flush();
   }
   if (Fields.size() != 1) {
     IsSupportedFlag = false;