[Driver] Make -X default for baremetal riscv

[phosek]

LGTM

clang/lib/Driver/ToolChains/BareMetal.cpp

341–346

Can you move it above -o so it's consistent with other drivers?

[kito-cheng]

clang/lib/Driver/ToolChains/BareMetal.cpp

341–346

I think we should do that for RV32 as well?

[abrachet]

Both comments addressed in commit

[MaskRay]

LGTM

clang/lib/Driver/ToolChains/BareMetal.cpp

if (TC.ShouldLinkCXXStdlib(Args))
     TC.AddCXXStdlibLibArgs(Args, CmdArgs);
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
     CmdArgs.push_back("-lc");
     CmdArgs.push_back("-lm");
 
     TC.AddLinkRuntimeLib(Args, CmdArgs);
   }
 
   CmdArgs.push_back("-o");
   CmdArgs.push_back(Output.getFilename());
 
+  if (TC.getArch() == llvm::Triple::riscv64)
+    CmdArgs.push_back("-X");
+
   C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
                                          Args.MakeArgString(TC.GetLinkerPath()),
                                          CmdArgs, Inputs, Output));
 }

clang/test/Driver/baremetal.cpp

 // CHECK-RV64-SAME: "-isysroot" "[[SYSROOT:[^"]*]]"
 // CHECK-RV64-SAME: "-internal-isystem" "[[SYSROOT]]{{[/\\]+}}include{{[/\\]+}}c++{{[/\\]+}}v1"
 // CHECk-RV64-SAME: "-internal-isystem" "[[SYSROOT]]{{[/\\]+}}include"
 // CHECK-RV64-SAME: "-x" "c++" "{{.*}}baremetal.cpp"
 // CHECK-RV64-NEXT: ld{{(.exe)?}}" "{{.*}}.o" "-Bstatic"
 // CHECK-RV64-SAME: "-Lsome{{[/\\]+}}directory{{[/\\]+}}user{{[/\\]+}}asked{{[/\\]+}}for"
 // CHECK-RV64-SAME: "-L[[SYSROOT:[^"]+]]{{[/\\]+}}lib"
 // CHECK-RV64-SAME: "-L[[RESOURCE_DIR:[^"]+]]{{[/\\]+}}lib{{[/\\]+}}baremetal"
-// CHECK-RV64-SAME: "-lc" "-lm" "-lclang_rt.builtins-riscv64" "-o" "{{.*}}.tmp.out"
+// CHECK-RV64-SAME: "-lc" "-lm" "-lclang_rt.builtins-riscv64" "-o" "{{.*}}.tmp.out" "-X"
 
 // RUN: %clangxx %s -### --target=riscv64-unknown-elf 2>&1 \
 // RUN:     --sysroot=%S/Inputs/basic_riscv64_tree/riscv64-unknown-elf \
 // RUN:   | FileCheck --check-prefix=CHECK-RV64-DEFAULTCXX %s
 // CHECK-RV64-DEFAULTCXX: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
 // CHECK-RV64-DEFAULTCXX: ld{{(.exe)?}}" "{{.*}}.o" "-Bstatic"
 // CHECK-RV64-DEFAULTCXX-SAME: "-L{{[^"]*}}{{[/\\]+}}Inputs{{[/\\]+}}basic_riscv64_tree{{[/\\]+}}riscv64-unknown-elf{{[/\\]+}}lib"
 // CHECK-RV64-DEFAULTCXX-SAME: "-L[[RESOURCE_DIR]]{{.*}}{{[/\\]+}}lib{{[/\\]+}}baremetal"
 // CHECK-RV64-DEFAULTCXX-SAME: "-lc++" "-lc++abi" "-lunwind"
-// CHECK-RV64-DEFAULTCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-riscv64" "-o" "a.out"
+// CHECK-RV64-DEFAULTCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-riscv64" "-o" "a.out" "-X"
 
 // RUN: %clangxx %s -### --target=riscv64-unknown-elf 2>&1 \
 // RUN:     --sysroot=%S/Inputs/basic_riscv64_tree/riscv64-unknown-elf \
 // RUN:     -stdlib=libc++ \
 // RUN:   | FileCheck --check-prefix=CHECK-RV64-LIBCXX %s
 // CHECK-RV64-LIBCXX: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
 // CHECK-RV64-LIBCXX-NOT: "-internal-isystem" "{{[^"]+}}{{[/\\]+}}include{{[/\\]+}}c++{{[/\\]+}}{{[^v].*}}"
 // CHECK-RV64-LIBCXX-SAME: "-internal-isystem" "{{[^"]+}}{{[/\\]+}}include{{[/\\]+}}c++{{[/\\]+}}v1"

 // RUN:   | FileCheck --check-prefix=CHECK-RV64-LIBSTDCXX %s
 // CHECK-RV64-LIBSTDCXX: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
 // CHECK-RV64-LIBSTDCXX-NOT: "-internal-isystem" "{{[^"]+}}{{[/\\]+}}include{{[/\\]+}}c++{{[/\\]+}}v1"
 // CHECK-RV64-LIBSTDCXX-SAME: "-internal-isystem" "{{[^"]+}}{{[/\\]+}}include{{[/\\]+}}c++{{[/\\]+}}8.0.1"
 // CHECK-RV64-LIBSTDCXX: ld{{(.exe)?}}" "{{.*}}.o" "-Bstatic"
 // CHECK-RV64-LIBSTDCXX-SAME: "-L{{[^"]*}}{{[/\\]+}}Inputs{{[/\\]+}}basic_riscv64_tree{{[/\\]+}}riscv64-unknown-elf{{[/\\]+}}lib"
 // CHECK-RV64-LIBSTDCXX-SAME: "-L[[RESOURCE_DIR]]{{[/\\]+}}lib{{[/\\]+}}baremetal"
 // CHECK-RV64-LIBSTDCXX-SAME: "-lstdc++" "-lsupc++" "-lunwind"
-// CHECK-RV64-LIBSTDCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-riscv64" "-o" "a.out"
+// CHECK-RV64-LIBSTDCXX-SAME: "-lc" "-lm" "-lclang_rt.builtins-riscv64" "-o" "a.out" "-X"
 
 // RUN: %clang %s -### 2>&1 --target=riscv32-unknown-elf \
 // RUN:     -L some/directory/user/asked/for \
 // RUN:     --sysroot=%S/Inputs/basic_riscv32_tree/riscv32-unknown-elf \
 // RUN:   | FileCheck --check-prefix=CHECK-RV32 %s
 // CHECK-RV32:      "-cc1" "-triple" "riscv32-unknown-unknown-elf"
 // CHECK-RV32-SAME: "-resource-dir" "[[RESOURCE_DIR:[^"]+]]"
 // CHECK-RV32-SAME: "-isysroot" "[[SYSROOT:[^"]*]]"