[AMDGPU] Add debugger related target options

[kzhuravl]

Summary

-mamdgpu-debugger-abi=<version>: sets all needed debugger related target features for given debugger abi <version>
-mamdgpu-debugger-insert-nops: sets +amdgpu-debugger-insert-nops target feature
-mamdgpu-debugger-reserve-trap-regs: sets +amdgpu-debugger-reserve-trap-regs target feature

[kzhuravl]

ping

[arsenm]

LGTM

include/clang/Driver/Options.td

 def m_arm_Features_Group : OptionGroup<"<arm features group>">,
                            Group<m_Group>;
 def m_aarch64_Features_Group : OptionGroup<"<aarch64 features group>">,
                                Group<m_Group>;
 def m_ppc_Features_Group : OptionGroup<"<ppc features group>">,
                            Group<m_Group>;
 def m_wasm_Features_Group : OptionGroup<"<wasm features group>">,
                             Group<m_Group>;
+def m_amdgpu_Features_Group : OptionGroup<"<amdgpu features group>">,
+                              Group<m_Group>;
 
 def m_libc_Group          : OptionGroup<"<m libc group>">, Group<m_Group>;
 def u_Group               : OptionGroup<"<u group>">;
 
 def pedantic_Group        : OptionGroup<"<pedantic group>">,
   Group<CompileOnly_Group>;
 def reserved_lib_Group   : OptionGroup<"<reserved libs group>">;
 
def mno_fix_cortex_a53_835769 : Flag<["-"], "mno-fix-cortex-a53-835769">,
   Group<m_aarch64_Features_Group>,
   HelpText<"Don't workaround Cortex-A53 erratum 835769 (AArch64 only)">;
 def ffixed_x18 : Flag<["-"], "ffixed-x18">, Group<m_aarch64_Features_Group>,
   HelpText<"Reserve the x18 register (AArch64 only)">;
 
 def msimd128 : Flag<["-"], "msimd128">, Group<m_wasm_Features_Group>;
 def mno_simd128 : Flag<["-"], "mno-simd128">, Group<m_wasm_Features_Group>;
 
+def mamdgpu_debugger_abi : Joined<["-"], "mamdgpu-debugger-abi=">,
+  Flags<[HelpHidden]>,
+  Group<m_Group>,
+  HelpText<"Generate additional code for specified <version> of debugger ABI (AMDGPU only)">,
+  MetaVarName<"<version>">;
+def mamdgpu_debugger_insert_nops : Flag<["-"], "mamdgpu-debugger-insert-nops">,
+  Group<m_amdgpu_Features_Group>;
+def mamdgpu_debugger_reserve_trap_regs : Flag<["-"], "mamdgpu-debugger-reserve-trap-regs">,
+  Group<m_amdgpu_Features_Group>;
+
 def mvsx : Flag<["-"], "mvsx">, Group<m_ppc_Features_Group>;
 def mno_vsx : Flag<["-"], "mno-vsx">, Group<m_ppc_Features_Group>;
 def mpower8_vector : Flag<["-"], "mpower8-vector">,
     Group<m_ppc_Features_Group>;
 def mno_power8_vector : Flag<["-"], "mno-power8-vector">,
     Group<m_ppc_Features_Group>;
 def mpower8_crypto : Flag<["-"], "mcrypto">,
     Group<m_ppc_Features_Group>;

lib/Driver/Tools.cpp

static void getHexagonTargetFeatures(const ArgList &Args,
   Features.push_back(HasHVXD ? "+hvx-double" : "-hvx-double");
 }
 
 static void getWebAssemblyTargetFeatures(const ArgList &Args,
                                          std::vector<const char *> &Features) {
   handleTargetFeaturesGroup(Args, Features, options::OPT_m_wasm_Features_Group);
 }
 
+static void getAMDGPUTargetFeatures(const Driver &D, const ArgList &Args,
+                                    std::vector<const char *> &Features) {
+  if (const Arg *dAbi = Args.getLastArg(options::OPT_mamdgpu_debugger_abi)) {
+    StringRef value = dAbi->getValue();
+    if (value == "1.0") {
+      Features.push_back("+amdgpu-debugger-insert-nops");
+      Features.push_back("+amdgpu-debugger-reserve-trap-regs");
+    } else {
+      D.Diag(diag::err_drv_clang_unsupported) << dAbi->getAsString(Args);
+    }
+  }
+
+  handleTargetFeaturesGroup(
+    Args, Features, options::OPT_m_amdgpu_Features_Group);
+}
+
 static void getTargetFeatures(const ToolChain &TC, const llvm::Triple &Triple,
                               const ArgList &Args, ArgStringList &CmdArgs,
                               bool ForAS) {
   const Driver &D = TC.getDriver();
   std::vector<const char *> Features;
   switch (Triple.getArch()) {
   default:
     break;
case llvm::Triple::x86_64:
     break;
   case llvm::Triple::hexagon:
     getHexagonTargetFeatures(Args, Features);
     break;
   case llvm::Triple::wasm32:
   case llvm::Triple::wasm64:
     getWebAssemblyTargetFeatures(Args, Features);
     break;
+  case llvm::Triple::r600:
+  case llvm::Triple::amdgcn:
+    getAMDGPUTargetFeatures(D, Args, Features);
+    break;
   }
 
   // Find the last of each feature.
   llvm::StringMap<unsigned> LastOpt;
   for (unsigned I = 0, N = Features.size(); I < N; ++I) {
     const char *Name = Features[I];
     assert(Name[0] == '-' || Name[0] == '+');
     LastOpt[Name + 1] = I;

test/Driver/amdgpu-features.c

+// Check handling of AMDGPU target features.
+//
+// -mamdgpu-debugger-abi=0.0
+// RUN: %clang -### -target amdgcn -x cl -S -emit-llvm -mcpu=kaveri -mamdgpu-debugger-abi=0.0 %s -o 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MAMDGPU-DEBUGGER-ABI-0-0 %s
+// CHECK-MAMDGPU-DEBUGGER-ABI-0-0: the clang compiler does not support '-mamdgpu-debugger-abi=0.0'
+//
+// -mamdgpu-debugger-abi=1.0
+// RUN: %clang -### -target amdgcn -x cl -S -emit-llvm -mcpu=kaveri -mamdgpu-debugger-abi=1.0 %s -o 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MAMDGPU-DEBUGGER-ABI-1-0 %s
+// CHECK-MAMDGPU-DEBUGGER-ABI-1-0: "-target-feature" "+amdgpu-debugger-insert-nops" "-target-feature" "+amdgpu-debugger-reserve-trap-regs"
+//
+// -mamdgpu-debugger-insert-nops
+// RUN: %clang -### -target amdgcn -x cl -S -emit-llvm -mcpu=kaveri -mamdgpu-debugger-insert-nops %s -o 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MAMDGPU-DEBUGGER-INSERT-NOPS %s
+// CHECK-MAMDGPU-DEBUGGER-INSERT-NOPS: "-target-feature" "+amdgpu-debugger-insert-nops"
+//
+// -mamdgpu-debugger-reserve-trap-regs
+// RUN: %clang -### -target amdgcn -x cl -S -emit-llvm -mcpu=kaveri -mamdgpu-debugger-reserve-trap-regs %s -o 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-MAMDGPU-DEBUGGER-RESERVE-TRAP-REGS %s
+// CHECK-MAMDGPU-DEBUGGER-RESERVE-TRAP-REGS: "-target-feature" "+amdgpu-debugger-reserve-trap-regs"