Add diagnostic back.

Author: srividya-sundaram

clang/lib/Driver/Driver.cpp

@@ -1087,6 +1087,16 @@ void Driver::CreateOffloadingDeviceToolChains(Compilation &C,
       C.getInputArgs().hasFlag(options::OPT_fsycl, options::OPT_fno_sycl,
                                false) ||
       hasSYCLDeviceOnly(C.getInputArgs());
+  bool IsSYCLOffloadArchEnabled =
+      HasValidSYCLRuntime &&
+      C.getInputArgs().hasArg(options::OPT_offload_arch_EQ);
+
+  if (IsSYCLOffloadArchEnabled &&
+      !C.getInputArgs().hasFlag(options::OPT_offload_new_driver,
+                                options::OPT_no_offload_new_driver, false)) {
+    Diag(clang::diag::err_drv_sycl_offload_arch_new_driver);
+    return;
+  }
 
   Arg *SYCLfpga = C.getInputArgs().getLastArg(options::OPT_fintelfpga);
 
@@ -7331,22 +7341,6 @@ void Driver::BuildActions(Compilation &C, DerivedArgList &Args,
 
   handleArguments(C, Args, Inputs, Actions);
 
-  bool HasValidSYCLRuntime =
-      C.getInputArgs().hasFlag(options::OPT_fsycl, options::OPT_fno_sycl,
-                               false) ||
-      hasSYCLDeviceOnly(C.getInputArgs());
-  bool IsSYCLOffloadArchEnabled =
-      HasValidSYCLRuntime &&
-      C.getInputArgs().hasArg(options::OPT_offload_arch_EQ);
-  /*
-    if (IsSYCLOffloadArchEnabled &&
-        !C.getInputArgs().hasFlag(options::OPT_offload_new_driver,
-                                  options::OPT_no_offload_new_driver, false)) {
-      Diag(clang::diag::err_drv_sycl_offload_arch_new_driver);
-      return;
-    }
-  */
-
   // If '-fintelfpga' is passed, add '-fsycl' to the list of arguments
   const llvm::opt::OptTable &Opts = getOpts();
   Arg *SYCLFpgaArg = C.getInputArgs().getLastArg(options::OPT_fintelfpga);

clang/lib/Driver/ToolChains/SYCL.cpp

@@ -27,11 +27,15 @@ using namespace clang::driver::tools;
 using namespace clang;
 using namespace llvm::opt;
 
+// Struct that relates an AOT target value with
+// Intel CPUs and GPUs.
 struct StringToOffloadArchIntelMap {
   const char *ArchName;
   OffloadArchIntel IntelArch;
 };
 
+// Mapping of valid --offload-arch values for Intel CPU and GPU
+// AOT targets.
 static const StringToOffloadArchIntelMap StringToArchNamesMap[] = {
     {"skylake-avx512", OffloadArchIntel::SKYLAKEAVX512},
     {"core-avx2", OffloadArchIntel::COREAVX2},
@@ -91,6 +95,8 @@ static const StringToOffloadArchIntelMap StringToArchNamesMap[] = {
     {"bmg_g21", OffloadArchIntel::BMG_G21},
     {"lnl_m", OffloadArchIntel::LNL_M}};
 
+// Check if the user provided value for --offload-arch is a valid
+// Intel CPU or Intel GPU target.
 OffloadArchIntel
 clang::driver::StringToOffloadArchIntel(llvm::StringRef ArchNameAsString) {
   auto result = std::find_if(
@@ -103,6 +109,9 @@ clang::driver::StringToOffloadArchIntel(llvm::StringRef ArchNameAsString) {
   return result->IntelArch;
 }
 
+// This is a mapping between the user provided --offload-arch value for Intel
+// GPU targets and the spir64_gen device name accepted by OCLOC (the Intel GPU
+// AOT compiler).
 StringRef clang::driver::mapIntelGPUArchName(StringRef ArchName) {
   StringRef Arch;
   Arch = llvm::StringSwitch<StringRef>(ArchName)

clang/lib/Driver/ToolChains/SYCL.h

@@ -90,8 +90,13 @@ static inline bool IsIntelGPUOffloadArch(OffloadArchIntel Arch) {
   return Arch >= OffloadArchIntel::BDW && Arch <= OffloadArchIntel::LNL_M;
 }
 
+// Mapping of valid --offload-arch values for Intel CPU and GPU
+// AOT targets.
 OffloadArchIntel StringToOffloadArchIntel(llvm::StringRef ArchNameAsString);
 
+// This is a mapping between the user provided --offload-arch value for Intel
+// GPU targets and the spir64_gen device name accepted by OCLOC (the Intel GPU
+// AOT compiler).
 StringRef mapIntelGPUArchName(StringRef ArchName);
 
 class SYCLInstallationDetector {