Subzero: Add locking to prepare for multithreaded translation.

src/PNaClTranslator.cpp

 //===- subzero/src/PNaClTranslator.cpp - ICE from bitcode -----------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the PNaCl bitcode file to Ice, to machine code
@@ skipping 148 matching lines @@
   TopLevelParser &operator=(const TopLevelParser &) = delete;
 
 public:
   typedef std::vector<Ice::FunctionDeclaration *> FunctionDeclarationListType;
 
   TopLevelParser(Ice::Translator &Translator, NaClBitcodeHeader &Header,
                  NaClBitstreamCursor &Cursor, bool &ErrorStatus)
       : NaClBitcodeParser(Cursor), Translator(Translator), Header(Header),
         ErrorStatus(ErrorStatus), NumErrors(0), NumFunctionIds(0),
         NumFunctionBlocks(0), BlockParser(nullptr) {
+    // Note: This gives the reader uncontrolled access to the dump
+    // stream, which it can then use without locking.  TODO(kschimpf):
+    // Consider reworking the LLVM side to use e.g. a callback for
+    // errors.
+    Ice::OstreamLocker L(Translator.getContext());
     setErrStream(Translator.getContext()->getStrDump());
   }
 
   ~TopLevelParser() override {}
 
   Ice::Translator &getTranslator() { return Translator; }
 
   void setBlockParser(BlockParserBaseClass *NewBlockParser) {
     BlockParser = NewBlockParser;
   }
@@ skipping 2628 matching lines @@
   }
 
   void installDeclarationName(Ice::Translator &Trans,
                               Ice::GlobalDeclaration *Decl,
                               const Ice::IceString &Prefix, const char *Context,
                               uint32_t &NameIndex) {
     if (!Decl->hasName()) {
       Decl->setName(Trans.createUnnamedName(Prefix, NameIndex));
       ++NameIndex;
     } else {
-      Trans.checkIfUnnamedNameSafe(Decl->getName(), Context, Prefix,
-                                   Trans.getContext()->getStrDump());
+      Trans.checkIfUnnamedNameSafe(Decl->getName(), Context, Prefix);
     }
   }
 
   bool ParseBlock(unsigned BlockID) override;
 
   void ExitBlock() override {
     InstallGlobalNamesAndGlobalVarInitializers();
     getTranslator().emitConstants();
   }
 
@@ skipping 172 matching lines @@
 
   if (TopLevelBlocks != 1) {
     errs() << IRFilename
            << ": Contains more than one module. Found: " << TopLevelBlocks
            << "\n";
     ErrorStatus = true;
   }
 }
 
 } // end of namespace Ice