Rebased PNaCl localmods in LLVM to 223109

lib/LTO/LTOModule.cpp

 //===-- LTOModule.cpp - LLVM Link Time Optimizer --------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the Link Time Optimization library. This library is
@@ skipping 14 matching lines @@
 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/MC/MCParser/MCAsmParser.h"
 #include "llvm/MC/MCSection.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/MC/MCTargetAsmParser.h"
 #include "llvm/MC/SubtargetFeature.h"
 #include "llvm/Object/IRObjectFile.h"
 #include "llvm/Object/ObjectFile.h"
 #include "llvm/Support/CommandLine.h"
+#include "llvm/Support/ErrorHandling.h" // @LOCALMOD
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Host.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/TargetRegistry.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
 #include "llvm/Target/TargetRegisterInfo.h"
@@ skipping 117 matching lines @@
     return nullptr;
   }
   ErrorOr<Module *> MOrErr = parseBitcodeFile(*MBOrErr, *Context);
   if (std::error_code EC = MOrErr.getError()) {
     errMsg = EC.message();
     return nullptr;
   }
   std::unique_ptr<Module> M(MOrErr.get());
 
   std::string TripleStr = M->getTargetTriple();
+  // @LOCALMOD-BEGIN
+  // Pretend that we are ARM for name mangling and assembly conventions.
+  // https://code.google.com/p/nativeclient/issues/detail?id=2554
+  if (TripleStr == "le32-unknown-nacl") {
+    TripleStr = "armv7a-none-nacl-gnueabi";
+  }
+  // @LOCALMOD-END
   if (TripleStr.empty())
     TripleStr = sys::getDefaultTargetTriple();
   llvm::Triple Triple(TripleStr);
 
   // find machine architecture for this module
   const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg);
   if (!march)
     return nullptr;
 
   // construct LTOModule, hand over ownership of module and target
@@ skipping 381 matching lines @@
         addAsmGlobalSymbolUndef(Name);
       else if (Flags & object::BasicSymbolRef::SF_Global)
         addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_DEFAULT);
       else
         addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_INTERNAL);
       continue;
     }
 
     auto *F = dyn_cast<Function>(GV);
     if (IsUndefined) {
+      // @LOCALMOD-BEGIN
+      // Bitcode modules may have declarations for functions or globals
+      // which are unused. Ignore them here so that gold does not mistake
+      // them for undefined symbols.
+      if (GV->use_empty())
+        continue;
+      // @LOCALMOD-END
+
       addPotentialUndefinedSymbol(Sym, F != nullptr);
       continue;
     }
 
     if (F) {
       addDefinedFunctionSymbol(Sym);
       continue;
     }
 
     if (isa<GlobalVariable>(GV)) {
@@ skipping 39 matching lines @@
         if (!DepLibName.empty())
           _deplibs.push_back(DepLibName.data());
         else if (!Op.empty())
           _linkeropts.push_back(Op.data());
       }
     }
   }
 
   // Add other interesting metadata here.
 }