[driver][hip] Skip bundler if host action is nothing.

[tra]

clang/test/Driver/hip-syntax-only.hip

8

I'd include -target <GPU> and a comment describing that we're making sure that both host and device compilations are still executed.

[hliao]

clang/test/Driver/hip-syntax-only.hip

8

won't -fcuda-is-device be sufficient? that's option specific to device-side compilation.

[tra]

clang/test/Driver/hip-syntax-only.hip

8

It's sufficient, but we're currently comparing sort of apples (-fcuda-is-device) and oranges (-triple FOO) on these two lines. Changing it into -triple GPU -fcuda-is-device vs. -triple HOST would make it easier to understand what's the intent here.

clang/lib/Driver/Driver.cpp

for (auto *SB : SpecializedBuilders) {
         continue;
       SB->appendTopLevelActions(OffloadAL);
     }
 
     // If we can use the bundler, replace the host action by the bundling one in
     // the resulting list. Otherwise, just append the device actions. For
     // device only compilation, HostAction is a null pointer, therefore only do
     // this when HostAction is not a null pointer.
-    if (CanUseBundler && HostAction && !OffloadAL.empty()) {
+    if (CanUseBundler && HostAction &&
+        HostAction->getType() != types::TY_Nothing && !OffloadAL.empty()) {
       // Add the host action to the list in order to create the bundling action.
       OffloadAL.push_back(HostAction);
 
       // We expect that the host action was just appended to the action list
       // before this method was called.
       assert(HostAction == AL.back() && "Host action not in the list??");
       HostAction = C.MakeAction<OffloadBundlingJobAction>(OffloadAL);
       AL.back() = HostAction;

clang/test/Driver/hip-syntax-only.hip

+// REQUIRES: clang-driver
+// REQUIRES: x86-registered-target
+// REQUIRES: amdgpu-registered-target
+
+// RUN: %clang -### -x hip -nogpulib -target x86_64 -fsyntax-only %s 2>&1 | FileCheck %s
+
+// Check that there are commands for both host- and device-side compilations.
+//
+// CHECK-DAG: clang{{.*}}" "-cc1" {{.*}} "-fcuda-is-device"
+// CHECK-DAG: clang{{.*}}" "-cc1" "-triple" "x86_64"
+// CHECK-NOT: clang-offload-bundler"