Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -14,6 +14,7 @@
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/ObjCRuntime.h"
 #include "clang/Basic/Version.h"
+#include "clang/Basic/VirtualFileSystem.h"
 #include "clang/Config/config.h"
 #include "clang/Driver/Action.h"
 #include "clang/Driver/Compilation.h"
@@ -2151,8 +2152,14 @@
   // as gold requires -plugin to come before any -plugin-opt that -Wl might
   // forward.
   CmdArgs.push_back("-plugin");
+  // Try the full path first. However, if the file does not exist, just let gold
+  // fall back to regular library lookup instead of passing a known-invalid
+  // path. This is meant to fix non-standard Gentoo install of LLVMgold.so
+  // plugin.
   std::string Plugin =
       ToolChain.getDriver().Dir + "/../lib" CLANG_LIBDIR_SUFFIX "/LLVMgold.so";
+  if (!D.getVFS().exists(Plugin))
+    Plugin = "LLVMgold.so";
   CmdArgs.push_back(Args.MakeArgString(Plugin));
 
   // Try to pass driver level flags relevant to LTO code generation down to
Index: test/Driver/gold-lto.c
===================================================================
--- test/Driver/gold-lto.c
+++ test/Driver/gold-lto.c
@@ -3,14 +3,14 @@
 // RUN: %clang -target x86_64-unknown-linux -### %t.o -flto 2>&1 \
 // RUN:     -Wl,-plugin-opt=foo -O3 \
 // RUN:     | FileCheck %s --check-prefix=CHECK-X86-64-BASIC
-// CHECK-X86-64-BASIC: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-X86-64-BASIC: "-plugin" "{{.*}}LLVMgold.so"
 // CHECK-X86-64-BASIC: "-plugin-opt=O3"
 // CHECK-X86-64-BASIC: "-plugin-opt=foo"
 //
 // RUN: %clang -target x86_64-unknown-linux -### %t.o -flto 2>&1 \
 // RUN:     -march=corei7 -Wl,-plugin-opt=foo -Ofast \
 // RUN:     | FileCheck %s --check-prefix=CHECK-X86-64-COREI7
-// CHECK-X86-64-COREI7: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-X86-64-COREI7: "-plugin" "{{.*}}LLVMgold.so"
 // CHECK-X86-64-COREI7: "-plugin-opt=mcpu=corei7"
 // CHECK-X86-64-COREI7: "-plugin-opt=O3"
 // CHECK-X86-64-COREI7: "-plugin-opt=foo"
@@ -18,11 +18,11 @@
 // RUN: %clang -target arm-unknown-linux -### %t.o -flto 2>&1 \
 // RUN:     -march=armv7a -Wl,-plugin-opt=foo -O0 \
 // RUN:     | FileCheck %s --check-prefix=CHECK-ARM-V7A
-// CHECK-ARM-V7A: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-ARM-V7A: "-plugin" "{{.*}}LLVMgold.so"
 // CHECK-ARM-V7A: "-plugin-opt=mcpu=cortex-a8"
 // CHECK-ARM-V7A: "-plugin-opt=O0"
 // CHECK-ARM-V7A: "-plugin-opt=foo"
 //
 // RUN: %clang -target i686-linux-android -### %t.o -flto 2>&1 \
 // RUN:     | FileCheck %s --check-prefix=CHECK-X86-ANDROID
-// CHECK-X86-ANDROID: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-X86-ANDROID: "-plugin" "{{.*}}LLVMgold.so"
Index: test/Driver/lto.c
===================================================================
--- test/Driver/lto.c
+++ test/Driver/lto.c
@@ -36,19 +36,19 @@
 // RUN: %clang -target x86_64-unknown-linux -### %s -flto 2> %t
 // RUN: FileCheck -check-prefix=CHECK-LINK-LTO-ACTION < %t %s
 //
-// CHECK-LINK-LTO-ACTION: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-LINK-LTO-ACTION: "-plugin" "{{.*}}LLVMgold.so"
 
 // -flto=full should cause link using gold plugin
 // RUN: %clang -target x86_64-unknown-linux -### %s -flto=full 2> %t
 // RUN: FileCheck -check-prefix=CHECK-LINK-FULL-ACTION < %t %s
 //
-// CHECK-LINK-FULL-ACTION: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-LINK-FULL-ACTION: "-plugin" "{{.*}}LLVMgold.so"
 
 // Check that subsequent -fno-lto takes precedence
 // RUN: %clang -target x86_64-unknown-linux -### %s -flto=full -fno-lto 2> %t
 // RUN: FileCheck -check-prefix=CHECK-LINK-NOLTO-ACTION < %t %s
 //
-// CHECK-LINK-NOLTO-ACTION-NOT: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-LINK-NOLTO-ACTION-NOT: "-plugin" "{{.*}}LLVMgold.so"
 
 // -flto passes along an explicit debugger tuning argument.
 // RUN: %clang -target x86_64-unknown-linux -### %s -flto -glldb 2> %t
Index: test/Driver/thinlto.c
===================================================================
--- test/Driver/thinlto.c
+++ test/Driver/thinlto.c
@@ -19,19 +19,19 @@
 // RUN: %clang -target x86_64-unknown-linux -### %s -flto=full -fno-lto -flto=thin 2> %t
 // RUN: FileCheck -check-prefix=CHECK-LINK-THIN-ACTION < %t %s
 //
-// CHECK-LINK-THIN-ACTION: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-LINK-THIN-ACTION: "-plugin" "{{.*}}LLVMgold.so"
 // CHECK-LINK-THIN-ACTION: "-plugin-opt=thinlto"
 
 // Check that subsequent -flto=full takes precedence
 // RUN: %clang -target x86_64-unknown-linux -### %s -flto=thin -flto=full 2> %t
 // RUN: FileCheck -check-prefix=CHECK-LINK-FULL-ACTION < %t %s
 //
-// CHECK-LINK-FULL-ACTION: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-LINK-FULL-ACTION: "-plugin" "{{.*}}LLVMgold.so"
 // CHECK-LINK-FULL-ACTION-NOT: "-plugin-opt=thinlto"
 
 // Check that subsequent -fno-lto takes precedence
 // RUN: %clang -target x86_64-unknown-linux -### %s -flto=thin -fno-lto 2> %t
 // RUN: FileCheck -check-prefix=CHECK-LINK-NOLTO-ACTION < %t %s
 //
-// CHECK-LINK-NOLTO-ACTION-NOT: "-plugin" "{{.*}}/LLVMgold.so"
+// CHECK-LINK-NOLTO-ACTION-NOT: "-plugin" "{{.*}}LLVMgold.so"
 // CHECK-LINK-NOLTO-ACTION-NOT: "-plugin-opt=thinlto"