[LTO] Handle Task=-1 passed to addSaveTemps

Summary:
This change is necessary for D46464, which will pass -1 as the Task
ID for distributed backends, so that the save temps files don't end
up with "4294967295" in their path. For distributed back ends, when -1
is passed, don't append any Task ID.

An existing test (tools/clang/test/CodeGen/thinlto_backend.ll) will
fail without this change after D46464.

Reviewers: pcc

Subscribers: mehdi_amini, inglorion, llvm-commits

Differential Revision: https://reviews.llvm.org/D46488

llvm-svn: 331591

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp
index e55da169962..6367aac11f3 100644
--- a/llvm/lib/LTO/LTOBackend.cpp
+++ b/llvm/lib/LTO/LTOBackend.cpp
@@ -76,10 +76,12 @@ Error Config::addSaveTemps(std::string OutputFileName,
       // user hasn't requested using the input module's path, emit to a file
       // named from the provided OutputFileName with the Task ID appended.
       if (M.getModuleIdentifier() == "ld-temp.o" || !UseInputModulePath) {
-        PathPrefix = OutputFileName + utostr(Task);
+        PathPrefix = OutputFileName;
+        if (Task != (unsigned)-1)
+          PathPrefix += utostr(Task) + ".";
       } else
-        PathPrefix = M.getModuleIdentifier();
-      std::string Path = PathPrefix + "." + PathSuffix + ".bc";
+        PathPrefix = M.getModuleIdentifier() + ".";
+      std::string Path = PathPrefix + PathSuffix + ".bc";
       std::error_code EC;
       raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::F_None);
       // Because -save-temps is a debugging feature, we report the error