[Driver] Add multiclass OptInFlag and OptOutFlag to simplify boolean option definition

[dblaikie]

Seems like a reasonable direction - presumably every flag (that has a similar form in both driver and frontend) would be classified as one of these (opt in or opt out)? The ones you've migrated are just a sample/example?

[dblaikie]

Oh, meant to approve on the last.

[echristo]

This looks good to me. Might want to open a project around migrating everything.

clang/include/clang/Driver/Options.td

 // Indicates that this group should be flattened into its parent when generating
 // documentation.
 class DocFlatten { bit DocFlatten = 1; }
 
 // Indicates that this warning is ignored, but accepted with a warning for
 // GCC compatibility.
 class IgnoredGCCCompat : Flags<[HelpHidden]> {}
 
+// A boolean option which is opt-in in CC1. The positive option exists in CC1 and
+// Args.hasArg(OPT_ffoo) is used to check that the flag is enabled.
+// This is useful if the option is usually disabled.
+multiclass OptInFFlag<string name, string pos_prefix, string neg_prefix,
+                      string help, list<OptionFlag> flags=[]> {
+  def f#NAME : Flag<["-"], "f"#name>, Flags<!listconcat([CC1Option], flags)>,
+               HelpText<!strconcat(pos_prefix, help)>;
+  def fno_#NAME : Flag<["-"], "fno-"#name>, Flags<flags>,
+               HelpText<!strconcat(neg_prefix, help)>;
+}
+
+// A boolean option which is opt-out in CC1. The negative option exists in CC1 and
+// Args.hasArg(OPT_fno_foo) is used to check that the flag is disabled.
+multiclass OptOutFFlag<string name, string pos_prefix, string neg_prefix,
+                       string help, list<OptionFlag> flags=[]> {
+  def f#NAME : Flag<["-"], "f"#name>, Flags<flags>, HelpText<!strconcat(pos_prefix, help)>;
+  def fno_ #NAME : Flag<["-"], "fno-"#name>, Flags<!listconcat([CC1Option], flags)>,
+               HelpText<!strconcat(neg_prefix, help)>;
+}
+
 /////////
 // Groups
 
 def Action_Group : OptionGroup<"<action group>">, DocName<"Actions">,
                    DocBrief<[{The action to perform on the input.}]>;
 
 // Meta-group for options which are only used for compilation,
 // and not linking etc.
def fprofile_filter_files_EQ : Joined<["-"], "fprofile-filter-files=">,
     HelpText<"Instrument only functions from files where names match any regex separated by a semi-colon">;
 def fprofile_exclude_files_EQ : Joined<["-"], "fprofile-exclude-files=">,
     Group<f_Group>, Flags<[CC1Option, CoreOption]>,
     HelpText<"Instrument only functions from files where names don't match all the regexes separated by a semi-colon">;
 def forder_file_instrumentation : Flag<["-"], "forder-file-instrumentation">,
     Group<f_Group>, Flags<[CC1Option, CoreOption]>,
     HelpText<"Generate instrumented code to collect order file into default.profraw file (overridden by '=' form of option or LLVM_PROFILE_FILE env var)">;
 
-def faddrsig : Flag<["-"], "faddrsig">, Group<f_Group>, Flags<[CoreOption, CC1Option]>,
-  HelpText<"Emit an address-significance table">;
-def fno_addrsig : Flag<["-"], "fno-addrsig">, Group<f_Group>, Flags<[CoreOption]>,
-  HelpText<"Don't emit an address-significance table">;
+defm addrsig : OptInFFlag<"addrsig", "Emit", "Don't emit", " an address-significance table", [CoreOption]>;
 def fblocks : Flag<["-"], "fblocks">, Group<f_Group>, Flags<[CoreOption, CC1Option]>,
   HelpText<"Enable the 'blocks' language feature">;
 def fbootclasspath_EQ : Joined<["-"], "fbootclasspath=">, Group<f_Group>;
 def fborland_extensions : Flag<["-"], "fborland-extensions">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Accept non-standard constructs supported by the Borland compiler">;
 def fbuiltin : Flag<["-"], "fbuiltin">, Group<f_Group>, Flags<[CoreOption]>;
 def fbuiltin_module_map : Flag <["-"], "fbuiltin-module-map">, Group<f_Group>,
   Flags<[DriverOption]>, HelpText<"Load the clang builtins module map file.">;
def ffast_math : Flag<["-"], "ffast-math">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Allow aggressive, lossy floating-point optimizations">;
 def fno_fast_math : Flag<["-"], "fno-fast-math">, Group<f_Group>;
 def fmath_errno : Flag<["-"], "fmath-errno">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Require math functions to indicate errors by setting errno">;
 def fno_math_errno : Flag<["-"], "fno-math-errno">, Group<f_Group>;
 def fbracket_depth_EQ : Joined<["-"], "fbracket-depth=">, Group<f_Group>, Flags<[CoreOption]>;
 def fsignaling_math : Flag<["-"], "fsignaling-math">, Group<f_Group>;
 def fno_signaling_math : Flag<["-"], "fno-signaling-math">, Group<f_Group>;
-def fjump_tables : Flag<["-"], "fjump-tables">, Group<f_Group>;
-def fno_jump_tables : Flag<["-"], "fno-jump-tables">, Group<f_Group>, Flags<[CC1Option]>,
-  HelpText<"Do not use jump tables for lowering switches">;
-def fforce_enable_int128 : Flag<["-"], "fforce-enable-int128">,
-  Group<f_Group>, Flags<[CC1Option]>,
-  HelpText<"Enable support for int128_t type">;
-def fno_force_enable_int128 : Flag<["-"], "fno-force-enable-int128">,
-  Group<f_Group>, Flags<[CC1Option]>,
-  HelpText<"Disable support for int128_t type">;
+defm jump_tables : OptOutFFlag<"jump-tables", "Use", "Do not use", " jump tables for lowering switches">;
+defm force_enable_int128 : OptInFFlag<"force-enable-int128", "Enable", "Disable", " support for int128_t type">;
 def fkeep_static_consts : Flag<["-"], "fkeep-static-consts">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Keep static const variables even if unused">;
 def ffixed_point : Flag<["-"], "ffixed-point">, Group<f_Group>,
                    Flags<[CC1Option]>, HelpText<"Enable fixed point types">;
 def fno_fixed_point : Flag<["-"], "fno-fixed-point">, Group<f_Group>,
                       HelpText<"Disable fixed point types">;
 def fcxx_static_destructors : Flag<["-"], "fc++-static-destructors">,
   Group<f_Group>,