[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

llvm-svn: 318816

3 files changed, 6 insertions, 1 deletions

diff --git a/clang/lib/Driver/ToolChain.cpp b/clang/lib/Driver/ToolChain.cpp
index fac0a5bbff5..741f4284cbb 100644
--- a/clang/lib/Driver/ToolChain.cpp
+++ b/clang/lib/Driver/ToolChain.cpp
@@ -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));
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 3ab28d471be..d96664cf0be 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -1869,7 +1869,7 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
   // 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)) {
diff --git a/clang/lib/Driver/ToolChains/Fuchsia.h b/clang/lib/Driver/ToolChains/Fuchsia.h
index 6d825fb8179..6f438deca7f 100644
--- a/clang/lib/Driver/ToolChains/Fuchsia.h
+++ b/clang/lib/Driver/ToolChains/Fuchsia.h
@@ -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;
   }