[Driver][SYCL] Adjust /MD settings for SYCL device compilations (#2497)

When setting /MD (by default) we do not want to pass the _MT and _DLL
predefines to the device compilations, only the host for clang-cl

Author: mdtoguchi

clang/lib/Driver/ToolChains/Clang.cpp

@@ -6783,9 +6783,9 @@ void Clang::AddClangCLArgs(const ArgList &Args, types::ID InputType,
                            bool *EmitCodeView) const {
   unsigned RTOptionID = options::OPT__SLASH_MT;
   bool isNVPTX = getToolChain().getTriple().isNVPTX();
-  bool isSYCL =
-      Args.hasArg(options::OPT_fsycl) ||
+  bool isSYCLDevice =
       getToolChain().getTriple().getEnvironment() == llvm::Triple::SYCLDevice;
+  bool isSYCL = Args.hasArg(options::OPT_fsycl) || isSYCLDevice;
   // For SYCL Windows, /MD is the default.
   if (isSYCL)
     RTOptionID = options::OPT__SLASH_MD;
@@ -6797,38 +6797,42 @@ void Clang::AddClangCLArgs(const ArgList &Args, types::ID InputType,
 
   if (Arg *A = Args.getLastArg(options::OPT__SLASH_M_Group)) {
     RTOptionID = A->getOption().getID();
-    if (isSYCL && (RTOptionID == options::OPT__SLASH_MT ||
-                   RTOptionID == options::OPT__SLASH_MTd))
+    if (isSYCL && !isSYCLDevice &&
+        (RTOptionID == options::OPT__SLASH_MT ||
+         RTOptionID == options::OPT__SLASH_MTd))
       // Use of /MT or /MTd is not supported for SYCL.
       getToolChain().getDriver().Diag(diag::err_drv_unsupported_opt_dpcpp)
           << A->getOption().getName();
   }
 
+  enum { addDEBUG = 0x1, addMT = 0x2, addDLL = 0x4 };
+  auto addPreDefines = [&](unsigned Defines) {
+    if (Defines & addDEBUG)
+      CmdArgs.push_back("-D_DEBUG");
+    if (Defines & addMT && !isSYCLDevice)
+      CmdArgs.push_back("-D_MT");
+    if (Defines & addDLL && !isSYCLDevice)
+      CmdArgs.push_back("-D_DLL");
+  };
   StringRef FlagForCRT;
   switch (RTOptionID) {
   case options::OPT__SLASH_MD:
-    if (Args.hasArg(options::OPT__SLASH_LDd))
-      CmdArgs.push_back("-D_DEBUG");
-    CmdArgs.push_back("-D_MT");
-    CmdArgs.push_back("-D_DLL");
+    addPreDefines((Args.hasArg(options::OPT__SLASH_LDd) ? addDEBUG : 0x0) |
+                  addMT | addDLL);
     FlagForCRT = "--dependent-lib=msvcrt";
     break;
   case options::OPT__SLASH_MDd:
-    CmdArgs.push_back("-D_DEBUG");
-    CmdArgs.push_back("-D_MT");
-    CmdArgs.push_back("-D_DLL");
+    addPreDefines(addDEBUG | addMT | addDLL);
     FlagForCRT = "--dependent-lib=msvcrtd";
     break;
   case options::OPT__SLASH_MT:
-    if (Args.hasArg(options::OPT__SLASH_LDd))
-      CmdArgs.push_back("-D_DEBUG");
-    CmdArgs.push_back("-D_MT");
+    addPreDefines((Args.hasArg(options::OPT__SLASH_LDd) ? addDEBUG : 0x0) |
+                  addMT);
     CmdArgs.push_back("-flto-visibility-public-std");
     FlagForCRT = "--dependent-lib=libcmt";
     break;
   case options::OPT__SLASH_MTd:
-    CmdArgs.push_back("-D_DEBUG");
-    CmdArgs.push_back("-D_MT");
+    addPreDefines(addDEBUG | addMT);
     CmdArgs.push_back("-flto-visibility-public-std");
     FlagForCRT = "--dependent-lib=libcmtd";
     break;

clang/test/Driver/sycl-MD-default.cpp

@@ -4,14 +4,17 @@
 // RUN:   | FileCheck -check-prefix=CHK-DEFAULT %s
 // RUN: %clangxx -### -fsycl -c -target x86_64-unknown-windows-msvc %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHK-DEFAULT %s
+// CHK-DEFAULT-NOT: "-fsycl-is-device" {{.*}} "-D_MT" "-D_DLL"
+// CHK-DEFAULT: "-fsycl-is-host" "-D_MT" "-D_DLL" "--dependent-lib=msvcrt{{d*}}" {{.*}}
+
 // RUN: %clang_cl -### -fsycl -c %s 2>&1 \
-// RUN:   | FileCheck -check-prefix=CHK-DEFAULT %s
+// RUN:   | FileCheck -check-prefix=CHK-DEFAULT-CL %s
 // RUN: %clang_cl -### -MD -fsycl -c %s 2>&1 \
-// RUN:   | FileCheck -check-prefix=CHK-DEFAULT %s
+// RUN:   | FileCheck -check-prefix=CHK-DEFAULT-CL %s
 // RUN: %clang_cl -### -MDd -fsycl -c %s 2>&1 \
-// RUN:   | FileCheck -check-prefix=CHK-DEFAULT %s
-// CHK-DEFAULT: "-D_MT" "-D_DLL"
-// CHK-DEFAULT: "--dependent-lib=msvcrt{{d*}}"
+// RUN:   | FileCheck -check-prefix=CHK-DEFAULT-CL %s
+// CHK-DEFAULT-CL-NOT: "-fsycl-is-device" {{.*}} "-D_MT" "-D_DLL"
+// CHK-DEFAULT-CL: "-D_MT" "-D_DLL" "--dependent-lib=msvcrt{{d*}}" {{.*}} "-fsycl-is-host"
 
 // RUN: %clang_cl -### -MT -fsycl -c %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHK-ERROR %s