[CUDA] Add option to generate relocatable device code

As a first step, pass '-c/--compile-only' to ptxas so that it
doesn't complain about references to external function. This
will successfully generate object files, but they won't work
at runtime because the registration routines need to adapted.

Differential Revision: https://reviews.llvm.org/D42921

llvm-svn: 324878

1 files changed, 15 insertions, 5 deletions

diff --git a/clang/lib/Driver/ToolChains/Cuda.cpp b/clang/lib/Driver/ToolChains/Cuda.cpp
index e513e818ebf..86a11847e5a 100644
--- a/clang/lib/Driver/ToolChains/Cuda.cpp
+++ b/clang/lib/Driver/ToolChains/Cuda.cpp
@@ -355,11 +355,17 @@ void NVPTX::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
   for (const auto& A : Args.getAllArgValues(options::OPT_Xcuda_ptxas))
     CmdArgs.push_back(Args.MakeArgString(A));
 
-  // In OpenMP we need to generate relocatable code.
-  if (JA.isOffloading(Action::OFK_OpenMP) &&
-      Args.hasFlag(options::OPT_fopenmp_relocatable_target,
-                   options::OPT_fnoopenmp_relocatable_target,
-                   /*Default=*/ true))
+  bool Relocatable = false;
+  if (JA.isOffloading(Action::OFK_OpenMP))
+    // In OpenMP we need to generate relocatable code.
+    Relocatable = Args.hasFlag(options::OPT_fopenmp_relocatable_target,
+                               options::OPT_fnoopenmp_relocatable_target,
+                               /*Default=*/true);
+  else if (JA.isOffloading(Action::OFK_Cuda))
+    Relocatable = Args.hasFlag(options::OPT_fcuda_rdc,
+                               options::OPT_fno_cuda_rdc, /*Default=*/false);
+
+  if (Relocatable)
     CmdArgs.push_back("-c");
 
   const char *Exec;
@@ -540,6 +546,10 @@ void CudaToolChain::addClangTargetOptions(
     if (DriverArgs.hasFlag(options::OPT_fcuda_approx_transcendentals,
                            options::OPT_fno_cuda_approx_transcendentals, false))
       CC1Args.push_back("-fcuda-approx-transcendentals");
+
+    if (DriverArgs.hasFlag(options::OPT_fcuda_rdc, options::OPT_fno_cuda_rdc,
+                           false))
+      CC1Args.push_back("-fcuda-rdc");
   }
 
   if (DriverArgs.hasArg(options::OPT_nocudalib))