r318816 - [Driver] Make the use of relax relocations a per target option

[Petr Hosek via cfe-commits]

Author: phosek
Date: Tue Nov 21 17:38:31 2017
New Revision: 318816

URL: http://llvm.org/viewvc/llvm-project?rev=318816&view=rev
Log:
[Driver] Make the use of relax relocations a per target option

The support for relax relocations is dependent on the linker and
different toolchains within the same compiler can be using different
linkers some of which may or may not support relax relocations.

Give toolchains the option to control whether they want to use relax
relocations in addition to the existing (global) build system option.

Differential Revision: https://reviews.llvm.org/D39831

Modified:
    cfe/trunk/cmake/caches/Fuchsia-stage2.cmake
    cfe/trunk/include/clang/Driver/ToolChain.h
    cfe/trunk/lib/Driver/ToolChain.cpp
    cfe/trunk/lib/Driver/ToolChains/Clang.cpp
    cfe/trunk/lib/Driver/ToolChains/Fuchsia.h
    cfe/trunk/test/Driver/fuchsia.c

Modified: cfe/trunk/cmake/caches/Fuchsia-stage2.cmake
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/cmake/caches/Fuchsia-stage2.cmake?rev=318816&r1=318815&r2=318816&view=diff
==============================================================================
--- cfe/trunk/cmake/caches/Fuchsia-stage2.cmake (original)
+++ cfe/trunk/cmake/caches/Fuchsia-stage2.cmake Tue Nov 21 17:38:31 2017
@@ -18,13 +18,6 @@ if(NOT APPLE)
   set(CLANG_DEFAULT_LINKER lld CACHE STRING "")
 endif()
 
-# This is a "Does your linker support it?" option that only applies
-# to x86-64 ELF targets.  All Fuchsia target linkers do support it.
-# For x86-64 Linux, it's supported by LLD and by GNU linkers since
-# binutils 2.27, so one can hope that all Linux hosts in use handle it.
-# Ideally this would be settable as a per-target option.
-set(ENABLE_X86_RELAX_RELOCATIONS ON CACHE BOOL "")
-
 if(APPLE)
   set(LLDB_CODESIGN_IDENTITY "" CACHE STRING "")
 endif()

Modified: cfe/trunk/include/clang/Driver/ToolChain.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Driver/ToolChain.h?rev=318816&r1=318815&r2=318816&view=diff
==============================================================================
--- cfe/trunk/include/clang/Driver/ToolChain.h (original)
+++ cfe/trunk/include/clang/Driver/ToolChain.h Tue Nov 21 17:38:31 2017
@@ -316,6 +316,9 @@ public:
   /// mixed dispatch method be used?
   virtual bool UseObjCMixedDispatch() const { return false; }
 
+  /// \brief Check whether to enable x86 relax relocations by default.
+  virtual bool useRelaxRelocations() const;
+
   /// GetDefaultStackProtectorLevel - Get the default stack protector level for
   /// this tool chain (0=off, 1=on, 2=strong, 3=all).
   virtual unsigned GetDefaultStackProtectorLevel(bool KernelOrKext) const {

Modified: cfe/trunk/lib/Driver/ToolChain.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChain.cpp?rev=318816&r1=318815&r2=318816&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/ToolChain.cpp (original)
+++ cfe/trunk/lib/Driver/ToolChain.cpp Tue Nov 21 17:38:31 2017
@@ -90,6 +90,10 @@ bool ToolChain::useIntegratedAs() const
                       IsIntegratedAssemblerDefault());
 }
 
+bool ToolChain::useRelaxRelocations() const {
+  return ENABLE_X86_RELAX_RELOCATIONS;
+}
+
 const SanitizerArgs& ToolChain::getSanitizerArgs() const {
   if (!SanitizerArguments.get())
     SanitizerArguments.reset(new SanitizerArgs(*this, Args));

Modified: cfe/trunk/lib/Driver/ToolChains/Clang.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains/Clang.cpp?rev=318816&r1=318815&r2=318816&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/ToolChains/Clang.cpp (original)
+++ cfe/trunk/lib/Driver/ToolChains/Clang.cpp Tue Nov 21 17:38:31 2017
@@ -1869,7 +1869,7 @@ static void CollectArgsForIntegratedAsse
   // arg after parsing the '-I' arg.
   bool TakeNextArg = false;
 
-  bool UseRelaxRelocations = ENABLE_X86_RELAX_RELOCATIONS;
+  bool UseRelaxRelocations = C.getDefaultToolChain().useRelaxRelocations();
   const char *MipsTargetFeature = nullptr;
   for (const Arg *A :
        Args.filtered(options::OPT_Wa_COMMA, options::OPT_Xassembler)) {

Modified: cfe/trunk/lib/Driver/ToolChains/Fuchsia.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/ToolChains/Fuchsia.h?rev=318816&r1=318815&r2=318816&view=diff
==============================================================================
--- cfe/trunk/lib/Driver/ToolChains/Fuchsia.h (original)
+++ cfe/trunk/lib/Driver/ToolChains/Fuchsia.h Tue Nov 21 17:38:31 2017
@@ -43,6 +43,7 @@ public:
   bool HasNativeLLVMSupport() const override { return true; }
   bool IsIntegratedAssemblerDefault() const override { return true; }
   bool IsMathErrnoDefault() const override { return false; }
+  bool useRelaxRelocations() const override { return true; };
   RuntimeLibType GetDefaultRuntimeLibType() const override {
     return ToolChain::RLT_CompilerRT;
   }

Modified: cfe/trunk/test/Driver/fuchsia.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/fuchsia.c?rev=318816&r1=318815&r2=318816&view=diff
==============================================================================
--- cfe/trunk/test/Driver/fuchsia.c (original)
+++ cfe/trunk/test/Driver/fuchsia.c Tue Nov 21 17:38:31 2017
@@ -5,6 +5,7 @@
 // RUN:     --sysroot=%S/platform 2>&1 \
 // RUN:     | FileCheck -check-prefixes=CHECK,CHECK-AARCH64 %s
 // CHECK: {{.*}}clang{{.*}}" "-cc1"
+// CHECK: "--mrelax-relocations"
 // CHECK: "-munwind-tables"
 // CHECK: "-fuse-init-array"
 // CHECK: "-isysroot" "[[SYSROOT:[^"]+]]"