[SYCL][Driver] Error for -foffload-lto and -fsycl-device-code-split=off

Signed-off-by: Sarnie, Nick <nick.sarnie@intel.com>

Author: sarnex

clang/lib/Driver/ToolChains/Clang.cpp

@@ -5846,12 +5846,17 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
       bool IsUsingOffloadNewDriver =
           Args.hasFlag(options::OPT_offload_new_driver,
                        options::OPT_no_offload_new_driver, false);
+      Arg *SYCLSplitMode =
+          Args.getLastArg(options::OPT_fsycl_device_code_split_EQ);
+      bool IsDeviceCodeSplitDisabled =
+          SYCLSplitMode && StringRef(SYCLSplitMode->getValue()) == "off";
       bool IsSYCLLTOSupported = JA.isDeviceOffloading(Action::OFK_SYCL) &&
-                                Triple.isSPIROrSPIRV() &&
-                                IsUsingOffloadNewDriver;
-      if (IsDeviceOffloadAction && !JA.isDeviceOffloading(Action::OFK_OpenMP) &&
-          !IsUsingOffloadNewDriver && !Triple.isAMDGPU() &&
-          !IsSYCLLTOSupported) {
+                                IsUsingOffloadNewDriver &&
+                                !IsDeviceCodeSplitDisabled;
+      if ((IsDeviceOffloadAction &&
+           !JA.isDeviceOffloading(Action::OFK_OpenMP) && !Triple.isAMDGPU() &&
+           !IsUsingOffloadNewDriver) ||
+          (JA.isDeviceOffloading(Action::OFK_SYCL) && !IsSYCLLTOSupported)) {
         D.Diag(diag::err_drv_unsupported_opt_for_target)
             << Args.getLastArg(options::OPT_foffload_lto,
                                options::OPT_foffload_lto_EQ)

clang/test/Driver/sycl-lto.cpp

@@ -4,6 +4,10 @@
 // RUN: not %clangxx -fsycl -foffload-lto=thin %s -### 2>&1 | FileCheck -check-prefix=CHECK_ERROR %s
 // CHECK_ERROR: unsupported option '-foffload-lto=thin' for target 'spir64-unknown-unknown'
 
+// Verify we error when using the new offload driver but with device code split set to off.
+// RUN: not %clangxx -fsycl --offload-new-driver -foffload-lto=thin -fsycl-device-code-split=off %s -### 2>&1 | FileCheck -check-prefix=CHECK_SPLIT_ERROR %s
+// CHECK_SPLIT_ERROR: unsupported option '-foffload-lto=thin' for target 'spir64-unknown-unknown'
+
 // Verify there's no error and we see the expected cc1 flags with the new offload driver.
 // RUN: %clangxx -fsycl --offload-new-driver -foffload-lto=thin %s -### 2>&1 | FileCheck -check-prefix=CHECK_SUPPORTED %s
 // CHECK_SUPPORTED: clang{{.*}} "-cc1" "-triple" "spir64-unknown-unknown" {{.*}} "-flto=thin" "-flto-unit"