[llvm] r313488 - [ThinLTO] Avoid archive member collisions with old API

[Johan Engelen via llvm-commits]

Author: jengelen
Date: Sun Sep 17 10:38:26 2017
New Revision: 313488

URL: http://llvm.org/viewvc/llvm-project?rev=313488&view=rev
Log:
[ThinLTO] Avoid archive member collisions with old API

Summary:
ld64 on OSX uses the old ThinLTOCodegenerator API. When two modules have the same name in an archive (valid archive), a name collision happens for the modules' buffer identifiers.
This PR resolves this, by suffixing the module name with an increasing number such that the identifiers are guaranteed to be unique.

For a similar fix in LLD, see https://reviews.llvm.org/D25495

Reviewers: mehdi_amini, tejohnson

Reviewed By: mehdi_amini

Subscribers: inglorion, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D37961

Modified:
    llvm/trunk/lib/LTO/ThinLTOCodeGenerator.cpp

Modified: llvm/trunk/lib/LTO/ThinLTOCodeGenerator.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/LTO/ThinLTOCodeGenerator.cpp?rev=313488&r1=313487&r2=313488&view=diff
==============================================================================
--- llvm/trunk/lib/LTO/ThinLTOCodeGenerator.cpp (original)
+++ llvm/trunk/lib/LTO/ThinLTOCodeGenerator.cpp Sun Sep 17 10:38:26 2017
@@ -535,7 +535,9 @@ static void initTMBuilder(TargetMachineB
 } // end anonymous namespace
 
 void ThinLTOCodeGenerator::addModule(StringRef Identifier, StringRef Data) {
-  ThinLTOBuffer Buffer(Data, Identifier);
+  std::string Id =
+      (Twine(Identifier) + "_" + std::to_string(Modules.size())).str();
+  ThinLTOBuffer Buffer(Data, std::move(Id));
   LLVMContext Context;
   StringRef TripleStr;
   ErrorOr<std::string> TripleOrErr = expectedToErrorOrAndEmitErrors(