From 7f29c6fcd31ea7fdba8be602cc6fee2d2016fcd3 Mon Sep 17 00:00:00 2001
From: Tom Stellard <tstellar@redhat.com>
Date: Tue, 11 Dec 2018 16:34:40 -0500
Subject: [PATCH] Disable threading in thinLTO

/usr/bin/ld.gold does not support threaded plugins if gold itself has
not been linked against pthread.

https://bugzilla.redhat.com/show_bug.cgi?id=1636479#c16
---
 lib/LTO/LTO.cpp           | 26 +-------------------------
 tools/gold/CMakeLists.txt |  1 +
 2 files changed, 2 insertions(+), 25 deletions(-)

diff --git a/lib/LTO/LTO.cpp b/lib/LTO/LTO.cpp
index 68d210cb..e4369c7f 100644
--- a/lib/LTO/LTO.cpp
+++ b/lib/LTO/LTO.cpp
@@ -914,7 +914,6 @@ public:
 
 namespace {
 class InProcessThinBackend : public ThinBackendProc {
-  ThreadPool BackendThreadPool;
   AddStreamFn AddStream;
   NativeObjectCache Cache;
   TypeIdSummariesByGuidTy TypeIdSummariesByGuid;
@@ -931,7 +930,6 @@ public:
       const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
       AddStreamFn AddStream, NativeObjectCache Cache)
       : ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries),
-        BackendThreadPool(ThinLTOParallelismLevel),
         AddStream(std::move(AddStream)), Cache(std::move(Cache)) {
     // Create a mapping from type identifier GUIDs to type identifier summaries.
     // This allows backends to use the type identifier GUIDs stored in the
@@ -996,34 +994,12 @@ public:
     assert(ModuleToDefinedGVSummaries.count(ModulePath));
     const GVSummaryMapTy &DefinedGlobals =
         ModuleToDefinedGVSummaries.find(ModulePath)->second;
-    BackendThreadPool.async(
-        [=](BitcodeModule BM, ModuleSummaryIndex &CombinedIndex,
-            const FunctionImporter::ImportMapTy &ImportList,
-            const FunctionImporter::ExportSetTy &ExportList,
-            const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>
-                &ResolvedODR,
-            const GVSummaryMapTy &DefinedGlobals,
-            MapVector<StringRef, BitcodeModule> &ModuleMap,
-            const TypeIdSummariesByGuidTy &TypeIdSummariesByGuid) {
-          Error E = runThinLTOBackendThread(
+    return runThinLTOBackendThread(
               AddStream, Cache, Task, BM, CombinedIndex, ImportList, ExportList,
               ResolvedODR, DefinedGlobals, ModuleMap, TypeIdSummariesByGuid);
-          if (E) {
-            std::unique_lock<std::mutex> L(ErrMu);
-            if (Err)
-              Err = joinErrors(std::move(*Err), std::move(E));
-            else
-              Err = std::move(E);
-          }
-        },
-        BM, std::ref(CombinedIndex), std::ref(ImportList), std::ref(ExportList),
-        std::ref(ResolvedODR), std::ref(DefinedGlobals), std::ref(ModuleMap),
-        std::ref(TypeIdSummariesByGuid));
-    return Error::success();
   }
 
   Error wait() override {
-    BackendThreadPool.wait();
     if (Err)
       return std::move(*Err);
     else
diff --git a/tools/gold/CMakeLists.txt b/tools/gold/CMakeLists.txt
index d2580329..c3bf1b72 100644
--- a/tools/gold/CMakeLists.txt
+++ b/tools/gold/CMakeLists.txt
@@ -15,4 +15,5 @@ if( LLVM_ENABLE_PIC AND LLVM_BINUTILS_INCDIR )
     gold-plugin.cpp
     )
 
+
 endif()
-- 
2.18.1