[Driver][SYCL] Use of -fsycl and -static-libstc++ not supported (#5297)

Emit an error when -fsycl -static-libstdc++ is used together.  This
combination is not supported due to the runtime dependence with libsycl.so

Author: mdtoguchi

clang/include/clang/Basic/DiagnosticDriverKinds.td

@@ -337,6 +337,8 @@ def err_drv_expecting_fsycl_with_sycl_opt : Error<
   "'%0' must be used in conjunction with '-fsycl' to enable offloading">;
 def err_drv_fsycl_with_c_type : Error<
   "'%0' must not be used in conjunction with '-fsycl', which expects C++ source">;
+def err_drv_fsycl_unsupported_with_opt
+  : Error<"'%0' is not supported with '-fsycl'">;
 def err_drv_sycl_missing_amdgpu_arch : Error<
   "missing AMDGPU architecture for SYCL offloading; specify it with '-Xsycl-target-backend --offload-arch'">;
 def warn_drv_sycl_offload_target_duplicate : Warning<

clang/lib/Driver/Driver.cpp

@@ -926,12 +926,18 @@ void Driver::CreateOffloadingDeviceToolChains(Compilation &C,
   if (SYCLTargets && SYCLfpga)
     Diag(clang::diag::err_drv_option_conflict)
         << SYCLTargets->getSpelling() << SYCLfpga->getSpelling();
+
+  auto argSYCLIncompatible = [&](OptSpecifier OptId) {
+    if (!HasValidSYCLRuntime)
+      return;
+    if (Arg *IncompatArg = C.getInputArgs().getLastArg(OptId))
+      Diag(clang::diag::err_drv_fsycl_unsupported_with_opt)
+          << IncompatArg->getSpelling();
+  };
+  // -static-libstdc++ is not compatible with -fsycl.
+  argSYCLIncompatible(options::OPT_static_libstdcxx);
   // -ffreestanding cannot be used with -fsycl
-  if (HasValidSYCLRuntime &&
-      C.getInputArgs().hasArg(options::OPT_ffreestanding)) {
-    Diag(clang::diag::err_drv_option_conflict) << "-fsycl"
-                                               << "-ffreestanding";
-  }
+  argSYCLIncompatible(options::OPT_ffreestanding);
 
   // Diagnose incorrect inputs to SYCL options.
   // FIXME: Since the option definition includes the list of possible values,

clang/test/Driver/sycl-offload.c

@@ -1137,10 +1137,12 @@
 // CHECK-HEADER-DIR: clang{{.*}} "-fsycl-is-device"{{.*}} "-internal-isystem" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl" "-internal-isystem" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include"
 // CHECK-HEADER-DIR: clang{{.*}} "-fsycl-is-host"{{.*}} "-internal-isystem" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include{{[/\\]+}}sycl" "-internal-isystem" "{{.*}}bin{{[/\\]+}}..{{[/\\]+}}include"{{.*}}
 
-/// Check for an incompatibility error when -fsycl and -ffreestanding used
+/// Check for option incompatibility with -fsycl
 // RUN:   %clang -### -fsycl -ffreestanding %s 2>&1 \
-// RUN:   | FileCheck -check-prefix=CHK-INCOMPATIBILITY %s
-// CHK-INCOMPATIBILITY: error: The option -fsycl conflicts with -ffreestanding
+// RUN:   | FileCheck -check-prefix=CHK-INCOMPATIBILITY %s -DINCOMPATOPT=-ffreestanding
+// RUN:   %clang -### -fsycl -static-libstdc++ %s 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHK-INCOMPATIBILITY %s -DINCOMPATOPT=-static-libstdc++
+// CHK-INCOMPATIBILITY: error: '[[INCOMPATOPT]]' is not supported with '-fsycl'
 
 /// Using -fsyntax-only with -fsycl should not emit IR
 // RUN:   %clang -### -fsycl -fsyntax-only %s 2>&1 \