[clang][Driver] Default to DIOp-based DIExpressions in SPIRV (llvm#1278)

Author: epilk

clang/lib/Driver/ToolChains/Clang.cpp

@@ -4982,10 +4982,16 @@ renderDebugOptions(const ToolChain &TC, const Driver &D, const llvm::Triple &T,
   renderDwarfFormat(D, T, Args, CmdArgs, EffectiveDWARFVersion);
   RenderDebugInfoCompressionArgs(Args, CmdArgs, D, TC);
 
-  bool EmitDwarfForAMDGCN = EmitDwarf && T.isAMDGCN();
+  bool EmitDwarfForAMDGCN =
+      EmitDwarf &&
+      (T.isAMDGCN() || (T.isSPIRV() && T.getVendor() == llvm::Triple::AMD));
   if (EmitDwarfForAMDGCN)
     CmdArgs.append({"-mllvm", "-amdgpu-spill-cfi-saved-regs"});
   if (Arg *A = Args.getLastArg(options::OPT_gheterogeneous_dwarf_EQ)) {
+    if (StringRef(A->getValue()) == "diexpr" && T.isSPIRV() &&
+        T.getVendor() == llvm::Triple::AMD)
+      D.Diag(clang::diag::err_drv_unsupported_opt_with_suggestion)
+          << A->getAsString(Args) << "-gheterogeneous-dwarf=diexpression";
     A->render(Args, CmdArgs);
   } else if (EmitDwarfForAMDGCN) {
 #ifndef NDEBUG

clang/test/Driver/amdgpu-debug.cl

@@ -46,3 +46,14 @@
 // Check that -gheterogeneous-dwarf= fails for unknown option
 // RUN: not %clang -target amdgcn-amd-amdhsa -x cl -c -nogpuinc -nogpulib  -emit-llvm -g -gheterogeneous-dwarf=unknown %s 2>&1 | FileCheck -check-prefix=CHECK-UNKNOWN %s
 // CHECK-UNKNOWN: error: invalid value
+
+// Check that =diexpression is implied by -g + spirv
+// RUN: %clang -### -target spirv64-amd-amdhsa -x cl -c -nogpuinc -nogpulib  -emit-llvm -g %s 2>&1 | FileCheck -check-prefix=CHECK-SPIRV %s
+// CHECK-SPIRV: "-cc1"
+// CHECK-SPIRV-DAG: "-mllvm" "-amdgpu-spill-cfi-saved-regs"
+// CHECK-SPIRV-DAG: "-gheterogeneous-dwarf=diexpression"
+// CHECK-SPIRV-DAG: "-debugger-tuning=gdb"
+
+// Check that =diexpr produces an error on spirv.
+// RUN: not %clang -### -target spirv64-amd-amdhsa -x cl -c -nogpuinc -nogpulib  -emit-llvm -g -gheterogeneous-dwarf=diexpr %s 2>&1 | FileCheck -check-prefix=CHECK-SPIRV-ERR %s
+// CHECK-SPIRV-ERR: error: unsupported option '-gheterogeneous-dwarf=diexpr'; did you mean '-gheterogeneous-dwarf=diexpression'?