[clang][cli] Port GNU language options to marshalling system

[jansvoboda11]

Summary

Port some GNU-related language options to the marshalling system for automatic command line parsing and generation.

[dexonsmith]

LGTM.

clang/include/clang/Driver/Options.td

 class MarshallingInfoVisibility<KeyPathAndMacro kpm, code default>
   : MarshallingInfoString<kpm, default>,
     Values<"default,hidden,internal,protected">,
     NormalizedValues<["DefaultVisibility", "HiddenVisibility",
                       "HiddenVisibility", "ProtectedVisibility"]>,
     AutoNormalizeEnum {}
 
 // Key paths that are constant during parsing of options with the same key path prefix.
+defvar cplusplus = LangOpts<"CPlusPlus">;
+defvar c99 = LangOpts<"C99">;
 defvar lang_std = LangOpts<"LangStd">;
 defvar open_cl = LangOpts<"OpenCL">;
+defvar gnu_mode = LangOpts<"GNUMode">;
 
 defvar std = !strconcat("LangStandard::getLangStandardForKind(", lang_std.KeyPath, ")");
 
 /////////
 // Options
 
 // The internal option ID must be a valid C++ identifier and results in a
 // clang::driver::options::OPT_XX enum constant for XX.
defm use_line_directives : BoolFOption<"use-line-directives",
   PosFlag<SetTrue, [CC1Option], "Use #line in preprocessed output">, NegFlag<SetFalse>>;
 
 def ffreestanding : Flag<["-"], "ffreestanding">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Assert that the compilation takes place in a freestanding environment">,
   MarshallingInfoFlag<LangOpts<"Freestanding">>;
 def fgnuc_version_EQ : Joined<["-"], "fgnuc-version=">, Group<f_Group>,
   HelpText<"Sets various macros to claim compatibility with the given GCC version (default is 4.2.1)">,
   Flags<[CC1Option, CoreOption]>;
-def fgnu_keywords : Flag<["-"], "fgnu-keywords">, Group<f_Group>, Flags<[CC1Option]>,
-  HelpText<"Allow GNU-extension keywords regardless of language standard">;
-defm gnu89_inline : OptInFFlag<"gnu89-inline", "Use the gnu89 inline semantics">;
+// We abuse '-f[no-]gnu-keywords' to force overriding all GNU-extension
+// keywords. This behavior is provided by GCC's poorly named '-fasm' flag,
+// while a subset (the non-C++ GNU keywords) is provided by GCC's
+// '-fgnu-keywords'. Clang conflates the two for simplicity under the single
+// name, as it doesn't seem a useful distinction.
+defm gnu_keywords : BoolFOption<"gnu-keywords",
+  LangOpts<"GNUKeywords">, Default<gnu_mode.KeyPath>,
+  PosFlag<SetTrue, [], "Allow GNU-extension keywords regardless of language standard">,
+  NegFlag<SetFalse>, BothFlags<[CC1Option]>>;
+defm gnu89_inline : BoolFOption<"gnu89-inline",
+  LangOpts<"GNUInline">, Default<!strconcat("!", c99.KeyPath, " && !", cplusplus.KeyPath)>,
+  PosFlag<SetTrue, [CC1Option], "Use the gnu89 inline semantics">,
+  NegFlag<SetFalse>>, ShouldParseIf<!strconcat("!", cplusplus.KeyPath)>;
 def fgnu_runtime : Flag<["-"], "fgnu-runtime">, Group<f_Group>,
   HelpText<"Generate output compatible with the standard GNU Objective-C runtime">;
 def fheinous_gnu_extensions : Flag<["-"], "fheinous-gnu-extensions">, Flags<[CC1Option]>,
   MarshallingInfoFlag<LangOpts<"HeinousExtensions">>;
 def filelist : Separate<["-"], "filelist">, Flags<[LinkerInput]>,
                Group<Link_Group>;
 def : Flag<["-"], "findirect-virtual-calls">, Alias<fapple_kext>;
 def finline_functions : Flag<["-"], "finline-functions">, Group<f_clang_Group>, Flags<[CC1Option]>,
defm digraphs : BoolFOption<"digraphs",
   PosFlag<SetTrue, [], "Enable alternative token representations '<:', ':>', '<%', '%>', '%:', '%:%:' (default)">,
   NegFlag<SetFalse, [], "Disallow alternative token representations '<:', ':>', '<%', '%>', '%:', '%:%:'">,
   BothFlags<[CC1Option]>>;
 def fno_declspec : Flag<["-"], "fno-declspec">, Group<f_clang_Group>,
   HelpText<"Disallow __declspec as a keyword">, Flags<[CC1Option]>;
 def fno_dollars_in_identifiers : Flag<["-"], "fno-dollars-in-identifiers">, Group<f_Group>,
   HelpText<"Disallow '$' in identifiers">, Flags<[CC1Option]>;
 def fno_eliminate_unused_debug_symbols : Flag<["-"], "fno-eliminate-unused-debug-symbols">, Group<f_Group>;
-def fno_gnu_keywords : Flag<["-"], "fno-gnu-keywords">, Group<f_Group>, Flags<[CC1Option]>;
 def fno_inline_functions : Flag<["-"], "fno-inline-functions">, Group<f_clang_Group>, Flags<[CC1Option]>;
 def fno_inline : Flag<["-"], "fno-inline">, Group<f_clang_Group>, Flags<[CC1Option]>;
 def fno_global_isel : Flag<["-"], "fno-global-isel">, Group<f_clang_Group>,
   HelpText<"Disables the global instruction selector">;
 def fno_experimental_isel : Flag<["-"], "fno-experimental-isel">, Group<f_clang_Group>,
   Alias<fno_global_isel>;
 def fveclib : Joined<["-"], "fveclib=">, Group<f_Group>, Flags<[CC1Option]>,
     HelpText<"Use the given vector functions library">,

clang/lib/Frontend/CompilerInvocation.cpp

 //===- CompilerInvocation.cpp ---------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
if (IMPLIED_CHECK)                                                         \
       KEYPATH = MERGER(KEYPATH, IMPLIED_VALUE);                                \
     if (SHOULD_PARSE)                                                          \
       if (auto MaybeValue =                                                    \
               NORMALIZER(OPT_##ID, TABLE_INDEX, ARGS, DIAGS, SUCCESS))         \
         KEYPATH =                                                              \
             MERGER(KEYPATH, static_cast<decltype(KEYPATH)>(*MaybeValue));      \
   }
 
+static const StringRef GetInputKindName(InputKind IK);
+
 static void FixupInvocation(CompilerInvocation &Invocation,
-                            DiagnosticsEngine &Diags,
-                            const InputArgList &Args) {
+                            DiagnosticsEngine &Diags, const InputArgList &Args,
+                            InputKind IK) {
   LangOptions &LangOpts = *Invocation.getLangOpts();
   CodeGenOptions &CodeGenOpts = Invocation.getCodeGenOpts();
   TargetOptions &TargetOpts = Invocation.getTargetOpts();
   FrontendOptions &FrontendOpts = Invocation.getFrontendOpts();
   CodeGenOpts.XRayInstrumentFunctions = LangOpts.XRayInstrument;
   CodeGenOpts.XRayAlwaysEmitCustomEvents = LangOpts.XRayAlwaysEmitCustomEvents;
   CodeGenOpts.XRayAlwaysEmitTypedEvents = LangOpts.XRayAlwaysEmitTypedEvents;
   CodeGenOpts.DisableFree = FrontendOpts.DisableFree;
static void FixupInvocation(CompilerInvocation &Invocation,
   if (LangOpts.NewAlignOverride &&
       !llvm::isPowerOf2_32(LangOpts.NewAlignOverride)) {
     Arg *A = Args.getLastArg(OPT_fnew_alignment_EQ);
     Diags.Report(diag::err_fe_invalid_alignment)
         << A->getAsString(Args) << A->getValue();
     LangOpts.NewAlignOverride = 0;
   }
 
+  if (Args.hasArg(OPT_fgnu89_inline) && LangOpts.CPlusPlus)
+    Diags.Report(diag::err_drv_argument_not_allowed_with)
+        << "-fgnu89-inline" << GetInputKindName(IK);
+
   if (Arg *A = Args.getLastArg(OPT_fdefault_calling_conv_EQ)) {
     auto DefaultCC = LangOpts.getDefaultCallingConv();
 
     bool emitError = (DefaultCC == LangOptions::DCC_FastCall ||
                       DefaultCC == LangOptions::DCC_StdCall) &&
                      Arch != llvm::Triple::x86;
     emitError |= (DefaultCC == LangOptions::DCC_VectorCall ||
                   DefaultCC == LangOptions::DCC_RegCall) &&
#endif
   Opts.C2x = Std.isC2x();
   Opts.CPlusPlus = Std.isCPlusPlus();
   Opts.CPlusPlus11 = Std.isCPlusPlus11();
   Opts.CPlusPlus14 = Std.isCPlusPlus14();
   Opts.CPlusPlus17 = Std.isCPlusPlus17();
   Opts.CPlusPlus20 = Std.isCPlusPlus20();
   Opts.CPlusPlus2b = Std.isCPlusPlus2b();
   Opts.GNUMode = Std.isGNUMode();
-  Opts.GNUInline = !Opts.C99 && !Opts.CPlusPlus;
   Opts.GNUCVersion = 0;
   Opts.HexFloats = Std.hasHexFloats();
   Opts.ImplicitInt = Std.hasImplicitInt();
 
   // Set OpenCL Version.
   Opts.OpenCL = Std.isOpenCL();
   if (LangStd == LangStandard::lang_opencl10)
     Opts.OpenCLVersion = 100;
#endif
   Opts.Bool = Opts.OpenCL || Opts.CPlusPlus;
 
   // OpenCL has half keyword
   Opts.Half = Opts.OpenCL;
 
   // C++ has wchar_t keyword.
   Opts.WChar = Opts.CPlusPlus;
 
-  Opts.GNUKeywords = Opts.GNUMode;
   Opts.CXXOperatorNames = Opts.CPlusPlus;
 
   Opts.AlignedAllocation = Opts.CPlusPlus17;
 
   Opts.DollarIdents = !Opts.AsmPreprocessor;
 
   // Enable [[]] attributes in C++11 and C2x by default.
   Opts.DoubleSquareBracketAttributes = Opts.CPlusPlus11 || Opts.C2x;
#undef LANG_OPTION_WITH_MARSHALLING
   // this option was added for compatibility with OpenCL 1.0.
   if (Args.getLastArg(OPT_cl_strict_aliasing)
        && Opts.OpenCLVersion > 100) {
     Diags.Report(diag::warn_option_invalid_ocl_version)
         << Opts.getOpenCLVersionTuple().getAsString()
         << Args.getLastArg(OPT_cl_strict_aliasing)->getAsString(Args);
   }
 
-  // We abuse '-f[no-]gnu-keywords' to force overriding all GNU-extension
-  // keywords. This behavior is provided by GCC's poorly named '-fasm' flag,
-  // while a subset (the non-C++ GNU keywords) is provided by GCC's
-  // '-fgnu-keywords'. Clang conflates the two for simplicity under the single
-  // name, as it doesn't seem a useful distinction.
-  Opts.GNUKeywords = Args.hasFlag(OPT_fgnu_keywords, OPT_fno_gnu_keywords,
-                                  Opts.GNUKeywords);
-
   if (Args.hasArg(OPT_fno_operator_names))
     Opts.CXXOperatorNames = 0;
 
   if (Opts.CUDAIsDevice && Args.hasArg(OPT_fcuda_approx_transcendentals))
     Opts.CUDADeviceApproxTranscendentals = 1;
 
   if (Args.hasArg(OPT_fgpu_allow_device_init)) {
     if (Opts.HIP)
if (Arg *A = Args.getLastArg(options::OPT_fgnuc_version_EQ)) {
     unsigned Patch = GNUCVer.getSubminor().getValueOr(0);
     if (Invalid || GNUCVer.getBuild() || Minor >= 100 || Patch >= 100) {
       Diags.Report(diag::err_drv_invalid_value)
           << A->getAsString(Args) << A->getValue();
     }
     Opts.GNUCVersion = Major * 100 * 100 + Minor * 100 + Patch;
   }
 
-  if (Args.hasArg(OPT_fgnu89_inline)) {
-    if (Opts.CPlusPlus)
-      Diags.Report(diag::err_drv_argument_not_allowed_with)
-        << "-fgnu89-inline" << GetInputKindName(IK);
-    else
-      Opts.GNUInline = 1;
-  }
-
   if (Args.hasArg(OPT_ftrapv)) {
     Opts.setSignedOverflowBehavior(LangOptions::SOB_Trapping);
     // Set the handler, if one is specified.
     Opts.OverflowHandler =
         std::string(Args.getLastArgValue(OPT_ftrapv_handler));
   }
   else if (Args.hasArg(OPT_fwrapv))
     Opts.setSignedOverflowBehavior(LangOptions::SOB_Defined);
if (Res.getCodeGenOpts().FineGrainedBitfieldAccesses &&
     Res.getCodeGenOpts().FineGrainedBitfieldAccesses = false;
     Diags.Report(diag::warn_drv_fine_grained_bitfield_accesses_ignored);
   }
 
   // Store the command-line for using in the CodeView backend.
   Res.getCodeGenOpts().Argv0 = Argv0;
   Res.getCodeGenOpts().CommandLineArgs = CommandLineArgs;
 
-  FixupInvocation(Res, Diags, Args);
+  FixupInvocation(Res, Diags, Args, DashX);
 
   return Success;
 }
 
 std::string CompilerInvocation::getModuleHash() const {
   // Note: For QoI reasons, the things we use as a hash here should all be
   // dumped via the -module-info flag.
   using llvm::hash_code;