[SYCL] Driver option to select SYCL version

Summary:
User can select the version of SYCL the compiler will
use via the flag -sycl-std, similar to -cl-std.

The flag defines the LangOpts.SYCLVersion option to the
version of SYCL. The default value is undefined.
If driver is building SYCL code, flag is set to the default SYCL
version (1.2.1)

The preprocessor uses this variable to define CL_SYCL_LANGUAGE_VERSION macro,
which should be defined according to SYCL 1.2.1 standard.

Only valid value at this point for the flag is 1.2.1.

Co-Authored-By: David Wood <Q0KPU0H1YOEPHRY1R2SN5B5RL@david.davidtw.co>
Signed-off-by: Ruyman Reyes <ruyman@codeplay.com>

Subscribers: ebevhan, Anastasia, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72857

1 files changed, 18 insertions, 2 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 48c65ad..9f3522a 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2544,6 +2544,24 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
       LangStd = OpenCLLangStd;
   }
 
+  Opts.SYCL = Args.hasArg(options::OPT_fsycl);
+  Opts.SYCLIsDevice = Opts.SYCL && Args.hasArg(options::OPT_fsycl_is_device);
+  if (Opts.SYCL) {
+    // -sycl-std applies to any SYCL source, not only those containing kernels,
+    // but also those using the SYCL API
+    if (const Arg *A = Args.getLastArg(OPT_sycl_std_EQ)) {
+      Opts.SYCLVersion = llvm::StringSwitch<unsigned>(A->getValue())
+                             .Cases("2017", "1.2.1", "121", "sycl-1.2.1", 2017)
+                             .Default(0U);
+
+      if (Opts.SYCLVersion == 0U) {
+        // User has passed an invalid value to the flag, this is an error
+        Diags.Report(diag::err_drv_invalid_value)
+            << A->getAsString(Args) << A->getValue();
+      }
+    }
+  }
+
   Opts.IncludeDefaultHeader = Args.hasArg(OPT_finclude_default_header);
   Opts.DeclareOpenCLBuiltins = Args.hasArg(OPT_fdeclare_opencl_builtins);
 
@@ -3145,8 +3163,6 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
           << Opts.OMPHostIRFile;
   }
 
-  Opts.SYCLIsDevice = Args.hasArg(options::OPT_fsycl_is_device);
-
   // Set CUDA mode for OpenMP target NVPTX if specified in options
   Opts.OpenMPCUDAMode = Opts.OpenMPIsDevice && T.isNVPTX() &&
                         Args.hasArg(options::OPT_fopenmp_cuda_mode);