Add kernel_arg_name regardless of unnamed arguments

If the user has requested `kernel_arg_name` metadata, always generate
it even if some or all of the kernel arguments are unnamed.

The `-spirv-gen-kernel-arg-name-md` option seems to be lacking tests
so far, so add a new test.

Author: svenvh

lib/SPIRV/SPIRVReader.cpp

@@ -2313,16 +2313,11 @@ bool SPIRVToLLVM::transKernelMetadata() {
                                  });
     // Generate metadata for kernel_arg_name
     if (SPIRVGenKernelArgNameMD) {
-      bool ArgHasName = true;
-      BF->foreachArgument([&](SPIRVFunctionParameter *Arg) {
-        ArgHasName &= !Arg->getName().empty();
-      });
-      if (ArgHasName)
-        addOCLKernelArgumentMetadata(Context, SPIR_MD_KERNEL_ARG_NAME, BF, F,
-                                     [=](SPIRVFunctionParameter *Arg) {
-                                       return MDString::get(*Context,
-                                                            Arg->getName());
-                                     });
+      addOCLKernelArgumentMetadata(Context, SPIR_MD_KERNEL_ARG_NAME, BF, F,
+                                   [=](SPIRVFunctionParameter *Arg) {
+                                     return MDString::get(*Context,
+                                                          Arg->getName());
+                                   });
     }
     // Generate metadata for reqd_work_group_size
     if (auto EM = BF->getExecutionMode(ExecutionModeLocalSize)) {

test/transcoding/kernel_arg_name.ll

@@ -0,0 +1,37 @@
+; RUN: llvm-as %s -o - | llvm-spirv -o %t.spv
+; RUN: llvm-spirv %t.spv -spirv-gen-kernel-arg-name-md -r -o - | llvm-dis -o - | FileCheck %s
+
+; CHECK: spir_kernel void @named_arg(float %f) {{.*}} !kernel_arg_name ![[MD_named:[0-9]+]]
+; CHECK: spir_kernel void @unnamed_arg(float) {{.*}} !kernel_arg_name ![[MD_unnamed:[0-9]+]]
+; CHECK: spir_kernel void @one_unnamed_arg(i8 %a, i8 %b, i8) {{.*}} !kernel_arg_name ![[MD_one_unnamed:[0-9]+]]
+
+; CHECK: ![[MD_unnamed]] = !{!""}
+; CHECK: ![[MD_named]] = !{!"f"}
+; CHECK: ![[MD_one_unnamed]] = !{!"a", !"b", !""}
+
+; ModuleID = 'kernel_arg_name.ll'
+source_filename = "kernel_arg_name.ll"
+target datalayout = "e-p:32:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024"
+target triple = "spir"
+
+; Function Attrs: norecurse nounwind readnone
+define spir_kernel void @named_arg(float %f) local_unnamed_addr #0 !kernel_arg_addr_space !0 !kernel_arg_access_qual !0 !kernel_arg_type !0 !kernel_arg_base_type !0 !kernel_arg_type_qual !0 {
+entry:
+  ret void
+}
+
+; Function Attrs: norecurse nounwind readnone
+define spir_kernel void @unnamed_arg(float) local_unnamed_addr #0 !kernel_arg_addr_space !0 !kernel_arg_access_qual !0 !kernel_arg_type !0 !kernel_arg_base_type !0 !kernel_arg_type_qual !0 {
+entry:
+  ret void
+}
+
+; Function Attrs: norecurse nounwind readnone
+define spir_kernel void @one_unnamed_arg(i8 %a, i8 %b, i8) local_unnamed_addr #0 !kernel_arg_addr_space !0 !kernel_arg_access_qual !0 !kernel_arg_type !0 !kernel_arg_base_type !0 !kernel_arg_type_qual !0 {
+entry:
+  ret void
+}
+
+attributes #0 = { norecurse nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!0 = !{}