Make sure that all globals are internal, except for "start" functions.

src/IceClFlags.cpp

 //===- subzero/src/IceClFlags.cpp - Command line flags and parsing --------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 16 matching lines @@
 
 // Options which are captured in Ice::ClFlags and propagated.
 
 namespace {
 
 cl::opt<bool> AllowErrorRecovery(
     "allow-pnacl-reader-error-recovery",
     cl::desc("Allow error recovery when reading PNaCl bitcode."),
     cl::init(false));
 
+cl::opt<bool> AllowExternDefinedSymbols(
+    "allow-externally-defined-symbols",
+    cl::desc("Allow global symbols to be externally defined (other than _start "
+             "and __pnacl_pso_root)."),
+    cl::init(false));
+
 cl::opt<bool> AllowIacaMarks(
     "allow-iaca-marks",
     cl::desc("Allow IACA (Intel Architecture Code Analyzer) marks to be "
              "inserted. These binaries are not executable."),
     cl::init(false));
 
 // This is currently needed by crosstest.py.
 cl::opt<bool> AllowUninitializedGlobals(
     "allow-uninitialized-globals",
     cl::desc("Allow global variables to be uninitialized"));
@@ skipping 306 matching lines @@
 namespace Ice {
 
 void ClFlags::parseFlags(int argc, char **argv) {
   cl::ParseCommandLineOptions(argc, argv);
   AppName = IceString(argv[0]);
 }
 
 void ClFlags::resetClFlags(ClFlags &OutFlags) {
   // bool fields
   OutFlags.AllowErrorRecovery = false;
+  OutFlags.AllowExternDefinedSymbols = false;
   OutFlags.AllowIacaMarks = false;
   OutFlags.AllowUninitializedGlobals = false;
   OutFlags.DataSections = false;
   OutFlags.DecorateAsm = false;
   OutFlags.DisableInternal = false;
   OutFlags.DisableIRGeneration = false;
   OutFlags.DisableTranslation = false;
   OutFlags.DumpStats = false;
   OutFlags.EnableBlockProfile = false;
   OutFlags.ForceMemIntrinOpt = false;
@@ skipping 40 matching lines @@
 
   Ice::VerboseMask VMask = Ice::IceV_None;
   // Don't generate verbose messages if routines to dump messages are not
   // available.
   if (BuildDefs::dump()) {
     for (unsigned i = 0; i != VerboseList.size(); ++i)
       VMask |= VerboseList[i];
   }
 
   OutFlags.setAllowErrorRecovery(::AllowErrorRecovery);
+  OutFlags.setAllowExternDefinedSymbols(::AllowExternDefinedSymbols ||
+                                        ::DisableInternal);
   OutFlags.setAllowIacaMarks(::AllowIacaMarks);
   OutFlags.setAllowUninitializedGlobals(::AllowUninitializedGlobals);
   OutFlags.setDataSections(::DataSections);
   OutFlags.setDecorateAsm(::DecorateAsm);
   OutFlags.setDefaultFunctionPrefix(::DefaultFunctionPrefix);
   OutFlags.setDefaultGlobalPrefix(::DefaultGlobalPrefix);
   OutFlags.setDisableInternal(::DisableInternal);
   OutFlags.setDisableIRGeneration(::DisableIRGeneration);
   OutFlags.setDisableTranslation(::DisableTranslation);
   OutFlags.setDumpStats(::DumpStats);
@@ skipping 40 matching lines @@
   OutFlagsExtra.setGenerateBuildAtts(GenerateBuildAtts);
   OutFlagsExtra.setLLVMVerboseErrors(LLVMVerboseErrors);
   OutFlagsExtra.setAppName(AppName);
   OutFlagsExtra.setInputFileFormat(InputFileFormat);
   OutFlagsExtra.setIRFilename(IRFilename);
   OutFlagsExtra.setLogFilename(LogFilename);
   OutFlagsExtra.setOutputFilename(OutputFilename);
 }
 
 } // end of namespace Ice