Revert "Revert "Fix LLVMgold plugin name/path for non-Linux.""

[danalbert]

Summary

Relanding https://reviews.llvm.org/D35739 which was reverted because
it broke the tests on non-Linux. The tests have been fixed to be
platform agnostic, and additional tests have been added to make sure
that the plugin has the correct extension on each platform
(%pluginext doesn't work in CHECK lines).

lib/Driver/ToolChains/CommonArgs.cpp

 
 void tools::AddGoldPlugin(const ToolChain &ToolChain, const ArgList &Args,
                           ArgStringList &CmdArgs, bool IsThinLTO,
                           const Driver &D) {
   // Tell the linker to load the plugin. This has to come before AddLinkerInputs
   // as gold requires -plugin to come before any -plugin-opt that -Wl might
   // forward.
   CmdArgs.push_back("-plugin");
-  std::string Plugin =
-      ToolChain.getDriver().Dir + "/../lib" CLANG_LIBDIR_SUFFIX "/LLVMgold.so";
+
+#if defined(LLVM_ON_WIN32)
+  const char *Suffix = ".dll";
+#elif defined(__APPLE__)
+  const char *Suffix = ".dylib";
+#else
+  const char *Suffix = ".so";
+#endif
+
+  SmallString<1024> Plugin;
+  llvm::sys::path::native(Twine(ToolChain.getDriver().Dir) +
+                              "/../lib" CLANG_LIBDIR_SUFFIX "/LLVMgold" +
+                              Suffix,
+                          Plugin);
   CmdArgs.push_back(Args.MakeArgString(Plugin));
 
   // Try to pass driver level flags relevant to LTO code generation down to
   // the plugin.
 
   // Handle flags for selecting CPU variants.
   std::string CPU = getCPUName(Args, ToolChain.getTriple());
   if (!CPU.empty())

test/Driver/freebsd.c

 // RUN:   | FileCheck --check-prefix=CHECK-ARM-EABIHF %s
 // CHECK-ARM-EABIHF-NOT: "-cc1"{{.*}}" "-fsjlj-exceptions"
 // CHECK-ARM-EABIHF: as{{.*}}" "-mfpu=vfp" "-meabi=5"
 // CHECK-ARM-EABIHF-NOT: as{{.*}}" "-mfpu=softvfp"
 // CHECK-ARM-EABIHF-NOT: as{{.*}}" "-matpcs"
 
 // RUN: %clang -target x86_64-pc-freebsd8 %s -### -flto 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-LTO %s
-// CHECK-LTO: ld{{.*}}" "-plugin{{.*}}LLVMgold.so
+// CHECK-LTO: ld{{.*}}" "-plugin{{.*}}LLVMgold.{{dll|dylib|so}}
 
 // RUN: %clang -target sparc-unknown-freebsd8 %s -### -fpic -no-integrated-as 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-SPARC-PIE %s
 // CHECK-SPARC-PIE: as{{.*}}" "-KPIC
 
 // RUN: %clang -mcpu=ultrasparc -target sparc64-unknown-freebsd8 %s -### -no-integrated-as 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-SPARC-CPU %s
 // CHECK-SPARC-CPU: cc1{{.*}}" "-target-cpu" "ultrasparc"
 // CHECK-SPARC-CPU: as{{.*}}" "-Av9
 
 // Check that -G flags are passed to the linker for mips
 // RUN: %clang -target mips-unknown-freebsd %s -### -G0 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-MIPS-G %s
 // CHECK-MIPS-G: ld{{.*}}" "-G0"

test/Driver/gold-lto.c

 // RUN: touch %t.o
 //
 // 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.{{dll|dylib|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.{{dll|dylib|so}}"
 // CHECK-X86-64-COREI7: "-plugin-opt=mcpu=corei7"
 // CHECK-X86-64-COREI7: "-plugin-opt=O3"
 // CHECK-X86-64-COREI7: "-plugin-opt=foo"
 //
 // 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.{{dll|dylib|so}}"
 // CHECK-ARM-V7A: "-plugin-opt=mcpu=generic"
 // 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.{{dll|dylib|so}}"

test/Driver/lto-plugin-darwin.c

+// Check that Darwin uses LLVMgold.dylib.
+// REQUIRES: system-darwin
+// RUN: %clang -### %s -flto 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-LTO-PLUGIN %s
+//
+// CHECK-LTO-PLUGIN: "-plugin" "{{.*}}/LLVMgold.dylib"

test/Driver/lto-plugin-linux.c

+// Check that non-Windows, non-Darwin OSs use LLVMgold.so.
+// REQUIRES: !system-darwin && !system-windows
+// RUN: %clang -### %s -flto 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-LTO-PLUGIN %s
+//
+// CHECK-LTO-PLUGIN: "-plugin" "{{.*}}/LLVMgold.so"

test/Driver/lto-plugin-windows.c

+// Check that Windows uses LLVMgold.dll.
+// REQUIRES: system-windows
+// RUN: %clang -### %s -flto 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-LTO-PLUGIN %s
+//
+// CHECK-LTO-PLUGIN: "-plugin" "{{.*}}/LLVMgold.dll"

test/Driver/lto.c

 
 // RUN: not %clang %s -emit-llvm 2>&1 | FileCheck --check-prefix=LLVM-LINK %s
 // LLVM-LINK: -emit-llvm cannot be used when linking
 
 // -flto should cause link using gold plugin
 // 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.{{dll|dylib|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.{{dll|dylib|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.{{dll|dylib|so}}"
 
 // -flto passes along an explicit debugger tuning argument.
 // RUN: %clang -target x86_64-unknown-linux -### %s -flto -glldb 2> %t
 // RUN: FileCheck -check-prefix=CHECK-TUNING-LLDB < %t %s
 // RUN: %clang -target x86_64-unknown-linux -### %s -flto -g 2> %t
 // RUN: FileCheck -check-prefix=CHECK-NO-TUNING < %t %s
 //
 // CHECK-TUNING-LLDB:   "-plugin-opt=-debugger-tune=lldb"
 // CHECK-NO-TUNING-NOT: "-plugin-opt=-debugger-tune

test/Driver/thinlto.c

 // CHECK-COMPILELINK-ACTIONS: 3: backend, {2}, lto-bc
 // CHECK-COMPILELINK-ACTIONS: 4: linker, {3}, image
 
 // -flto=thin should cause link using gold plugin with thinlto option,
 // also confirm that it takes precedence over earlier -fno-lto and -flto=full.
 // 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.{{dll|dylib|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.{{dll|dylib|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.{{dll|dylib|so}}"
 // CHECK-LINK-NOLTO-ACTION-NOT: "-plugin-opt=thinlto"