[flang][driver] Refactor boolean options

For boolean options, e.g. `-fxor-operator`/`-fno-xor-operator`, we ought
to be using TableGen multi-classes. This way, we only have to write one
definition to have both forms auto-generated. This patch refactors all
of Flang's boolean options to use two new multi-classes:
`OptInFC1FFOption` and `OptOutFC1FFOption`. These multi-classes are
based on `OptInFFOption`/`OptOutFFOption`, respectively. I've also
simplified the processing of the updated options in
CompilerInvocation.cpp.

With the new approach, "empty" help text (i.e. no `HelpText`) is now
replaced with an empty string (i.e. HelpText<"">). When running
flang-new --help, that's considered as non-empty help messages, which is
then printed (that's controlled by `printHelp` from
llvm/lib/Option/OptTable.cpp). This means that with this patch,
flang-new --help will start printing e.g. -fno-backslash, even though
there is no actual help text to print for this option (apart from the
empty string ""). Tests are updated accordingly.

Note that with this patch, both `-fxor-operator` and `-fno-xor-operator`
(and other boolean options refactored here) remain available in
`flang-new` and `flang-new -fc1`. In this respect, nothing changes. In a
forthcoming patch, I will refine this so that `flang-new -fc1` only
accepts `-ffoo` (`OptInFC1FFOption`) or `-fno-foo` (`OptOutCC1FFOption`).

For clarity, `OptInFFOption`/`OptOutFFOption` are renamed as
`OptInCC1FFOption`/`OptOutCC1FFOption`, respectively. Otherwise, this is
an NFC from Clang's perspective.

Differential Revision: https://reviews.llvm.org/D105881

Author: banach-space

clang/include/clang/Driver/Options.td

@@ -272,7 +272,7 @@ class MigratorOpts<string base>
 // Args.hasArg(OPT_ffoo) can be used to check that the flag is enabled.
 // This is useful if the option is usually disabled.
 // Use this only when the option cannot be declared via BoolFOption.
-multiclass OptInFFlag<string name, string pos_prefix, string neg_prefix="",
+multiclass OptInCC1FFlag<string name, string pos_prefix, string neg_prefix="",
                       string help="", list<OptionFlag> flags=[]> {
   def f#NAME : Flag<["-"], "f"#name>, Flags<[CC1Option] # flags>,
                Group<f_Group>, HelpText<pos_prefix # help>;
@@ -283,14 +283,35 @@ multiclass OptInFFlag<string name, string pos_prefix, string neg_prefix="",
 // A boolean option which is opt-out in CC1. The negative option exists in CC1 and
 // Args.hasArg(OPT_fno_foo) can be used to check that the flag is disabled.
 // Use this only when the option cannot be declared via BoolFOption.
-multiclass OptOutFFlag<string name, string pos_prefix, string neg_prefix,
+multiclass OptOutCC1FFlag<string name, string pos_prefix, string neg_prefix,
                        string help="", list<OptionFlag> flags=[]> {
   def f#NAME : Flag<["-"], "f"#name>, Flags<flags>,
                Group<f_Group>, HelpText<pos_prefix # help>;
   def fno_#NAME : Flag<["-"], "fno-"#name>, Flags<[CC1Option] # flags>,
                   Group<f_Group>, HelpText<neg_prefix # help>;
 }
 
+// A boolean option which is opt-in in FC1. The positive option exists in FC1 and
+// Args.hasArg(OPT_ffoo) can be used to check that the flag is enabled.
+// This is useful if the option is usually disabled.
+multiclass OptInFC1FFlag<string name, string pos_prefix, string neg_prefix="",
+                      string help="", list<OptionFlag> flags=[]> {
+  def f#NAME : Flag<["-"], "f"#name>, Flags<[FC1Option] # flags>,
+               Group<f_Group>, HelpText<pos_prefix # help>;
+  def fno_#NAME : Flag<["-"], "fno-"#name>, Flags<flags>,
+                  Group<f_Group>, HelpText<neg_prefix # help>;
+}
+
+// A boolean option which is opt-out in FC1. The negative option exists in FC1 and
+// Args.hasArg(OPT_fno_foo) can be used to check that the flag is disabled.
+multiclass OptOutFC1FFlag<string name, string pos_prefix, string neg_prefix,
+                       string help="", list<OptionFlag> flags=[]> {
+  def f#NAME : Flag<["-"], "f"#name>, Flags<flags>,
+               Group<f_Group>, HelpText<pos_prefix # help>;
+  def fno_#NAME : Flag<["-"], "fno-"#name>, Flags<[FC1Option] # flags>,
+                  Group<f_Group>, HelpText<neg_prefix # help>;
+}
+
 // Creates a positive and negative flags where both of them are prefixed with
 // "m", have help text specified for positive and negative option, and a Group
 // optionally specified by the opt_group argument, otherwise Group<m_Group>.
@@ -1257,7 +1278,7 @@ defm addrsig : BoolFOption<"addrsig",
   CodeGenOpts<"Addrsig">, DefaultFalse,
   PosFlag<SetTrue, [CC1Option], "Emit">, NegFlag<SetFalse, [], "Don't emit">,
   BothFlags<[CoreOption], " an address-significance table">>;
-defm blocks : OptInFFlag<"blocks", "Enable the 'blocks' language feature", "", "", [CoreOption]>;
+defm blocks : OptInCC1FFlag<"blocks", "Enable the 'blocks' language feature", "", "", [CoreOption]>;
 def fbootclasspath_EQ : Joined<["-"], "fbootclasspath=">, Group<f_Group>;
 defm borland_extensions : BoolFOption<"borland-extensions",
   LangOpts<"Borland">, DefaultFalse,
@@ -1273,7 +1294,7 @@ def fclang_abi_compat_EQ : Joined<["-"], "fclang-abi-compat=">, Group<f_clang_Gr
   Flags<[CC1Option]>, MetaVarName<"<version>">, Values<"<major>.<minor>,latest">,
   HelpText<"Attempt to match the ABI of Clang <version>">;
 def fclasspath_EQ : Joined<["-"], "fclasspath=">, Group<f_Group>;
-defm color_diagnostics : OptInFFlag<"color-diagnostics", "Enable", "Disable", " colors in diagnostics",
+defm color_diagnostics : OptInCC1FFlag<"color-diagnostics", "Enable", "Disable", " colors in diagnostics",
   [CoreOption, FlangOption]>;
 def fdiagnostics_color : Flag<["-"], "fdiagnostics-color">, Group<f_Group>,
   Flags<[CoreOption, NoXarchOption]>;
@@ -1394,7 +1415,7 @@ def fno_elide_type : Flag<["-"], "fno-elide-type">, Group<f_Group>,
     HelpText<"Do not elide types when printing diagnostics">,
     MarshallingInfoNegativeFlag<DiagnosticOpts<"ElideType">>;
 def feliminate_unused_debug_symbols : Flag<["-"], "feliminate-unused-debug-symbols">, Group<f_Group>;
-defm eliminate_unused_debug_types : OptOutFFlag<"eliminate-unused-debug-types",
+defm eliminate_unused_debug_types : OptOutCC1FFlag<"eliminate-unused-debug-types",
   "Do not emit ", "Emit ", " debug info for defined but unused types">;
 def femit_all_decls : Flag<["-"], "femit-all-decls">, Group<f_Group>, Flags<[CC1Option]>,
   HelpText<"Emit all declarations, even if unused">,
@@ -1499,7 +1520,7 @@ defm cxx_static_destructors : BoolFOption<"c++-static-destructors",
 def fsymbol_partition_EQ : Joined<["-"], "fsymbol-partition=">, Group<f_Group>,
   Flags<[CC1Option]>, MarshallingInfoString<CodeGenOpts<"SymbolPartition">>;
 
-defm memory_profile : OptInFFlag<"memory-profile", "Enable", "Disable", " heap memory profiling">;
+defm memory_profile : OptInCC1FFlag<"memory-profile", "Enable", "Disable", " heap memory profiling">;
 def fmemory_profile_EQ : Joined<["-"], "fmemory-profile=">,
     Group<f_Group>, Flags<[CC1Option]>, MetaVarName<"<directory>">,
     HelpText<"Enable heap memory profiling and dump results into <directory>">;
@@ -2143,9 +2164,9 @@ defm pch_instantiate_templates : BoolFOption<"pch-instantiate-templates",
   LangOpts<"PCHInstantiateTemplates">, DefaultFalse,
   PosFlag<SetTrue, [], "Instantiate templates already while building a PCH">,
   NegFlag<SetFalse>, BothFlags<[CC1Option, CoreOption]>>;
-defm pch_codegen: OptInFFlag<"pch-codegen", "Generate ", "Do not generate ",
+defm pch_codegen: OptInCC1FFlag<"pch-codegen", "Generate ", "Do not generate ",
   "code for uses of this PCH that assumes an explicit object file will be built for the PCH">;
-defm pch_debuginfo: OptInFFlag<"pch-debuginfo", "Generate ", "Do not generate ",
+defm pch_debuginfo: OptInCC1FFlag<"pch-debuginfo", "Generate ", "Do not generate ",
   "debug info for types in an object file built from this PCH and do not generate them elsewhere">;
 
 def fimplicit_module_maps : Flag <["-"], "fimplicit-module-maps">, Group<f_Group>,
@@ -4509,26 +4530,18 @@ def fdefault_real_8 : Flag<["-"],"fdefault-real-8">, Group<f_Group>,
   HelpText<"Set the default real kind to an 8 byte wide type">;
 def flarge_sizes : Flag<["-"],"flarge-sizes">, Group<f_Group>,
   HelpText<"Use INTEGER(KIND=8) for the result type in size-related intrinsics">;
-def fbackslash : Flag<["-"], "fbackslash">, Group<f_Group>,
-  HelpText<"Specify that backslash in string introduces an escape character">,
-  DocBrief<[{Change the interpretation of backslashes in string literals from
-a single backslash character to "C-style" escape characters.}]>;
-def fno_backslash : Flag<["-"], "fno-backslash">, Group<f_Group>;
-def fxor_operator : Flag<["-"], "fxor-operator">, Group<f_Group>,
-  HelpText<"Enable .XOR. as a synonym of .NEQV.">;
-def fno_xor_operator : Flag<["-"], "fno-xor-operator">, Group<f_Group>;
-def flogical_abbreviations : Flag<["-"], "flogical-abbreviations">, Group<f_Group>,
-  HelpText<"Enable logical abbreviations">;
-def fno_logical_abbreviations : Flag<["-"], "fno-logical-abbreviations">, Group<f_Group>;
-def fimplicit_none : Flag<["-"], "fimplicit-none">, Group<f_Group>,
-  HelpText<"No implicit typing allowed unless overridden by IMPLICIT statements">;
-def fno_implicit_none : Flag<["-"], "fno-implicit-none">, Group<f_Group>;
+
 def falternative_parameter_statement : Flag<["-"], "falternative-parameter-statement">, Group<f_Group>,
   HelpText<"Enable the old style PARAMETER statement">;
 def fintrinsic_modules_path : Separate<["-"], "fintrinsic-modules-path">,  Group<f_Group>, MetaVarName<"<dir>">,
   HelpText<"Specify where to find the compiled intrinsic modules">,
   DocBrief<[{This option specifies the location of pre-compiled intrinsic modules, 
   if they are not in the default location expected by the compiler.}]>;
+
+defm backslash : OptInFC1FFlag<"backslash", "Specify that backslash in string introduces an escape character">;
+defm xor_operator : OptInFC1FFlag<"xor-operator", "Enable .XOR. as a synonym of .NEQV.">;
+defm logical_abbreviations : OptInFC1FFlag<"logical-abbreviations", "Enable logical abbreviations">;
+defm implicit_none : OptInFC1FFlag<"implicit-none", "No implicit typing allowed unless overridden by IMPLICIT statements">;
 }
 
 def J : JoinedOrSeparate<["-"], "J">,
@@ -4583,13 +4596,10 @@ def fget_symbols_sources : Flag<["-"], "fget-symbols-sources">, Group<Action_Gro
 
 def module_suffix : Separate<["-"], "module-suffix">,  Group<f_Group>, MetaVarName<"<suffix>">,
   HelpText<"Use <suffix> as the suffix for module files (the default value is `.mod`)">;
-def fanalyzed_objects_for_unparse : Flag<["-"],
-  "fanalyzed-objects-for-unparse">,  Group<f_Group>;
-def fno_analyzed_objects_for_unparse : Flag<["-"],
-  "fno-analyzed-objects-for-unparse">,  Group<f_Group>,
-  HelpText<"Do not use the analyzed objects when unparsing">;
 def fno_reformat : Flag<["-"], "fno-reformat">, Group<Preprocessor_Group>,
   HelpText<"Dump the cooked character stream in -E mode">;
+defm analyzed_objects_for_unparse : OptOutFC1FFlag<"analyzed-objects-for-unparse", "", "Do not use the analyzed objects when unparsing">;
+
 }
 
 //===----------------------------------------------------------------------===//

flang/lib/Frontend/CompilerInvocation.cpp

@@ -277,32 +277,27 @@ static bool ParseFrontendArgs(FrontendOptions &opts, llvm::opt::ArgList &args,
     }
   }
 
-  if (const llvm::opt::Arg *arg =
-          args.getLastArg(clang::driver::options::OPT_fimplicit_none,
-              clang::driver::options::OPT_fno_implicit_none)) {
-    opts.features.Enable(
-        Fortran::common::LanguageFeature::ImplicitNoneTypeAlways,
-        arg->getOption().matches(clang::driver::options::OPT_fimplicit_none));
-  }
-  if (const llvm::opt::Arg *arg =
-          args.getLastArg(clang::driver::options::OPT_fbackslash,
-              clang::driver::options::OPT_fno_backslash)) {
-    opts.features.Enable(Fortran::common::LanguageFeature::BackslashEscapes,
-        arg->getOption().matches(clang::driver::options::OPT_fbackslash));
-  }
-  if (const llvm::opt::Arg *arg =
-          args.getLastArg(clang::driver::options::OPT_flogical_abbreviations,
-              clang::driver::options::OPT_fno_logical_abbreviations)) {
-    opts.features.Enable(Fortran::common::LanguageFeature::LogicalAbbreviations,
-        arg->getOption().matches(
-            clang::driver::options::OPT_flogical_abbreviations));
-  }
-  if (const llvm::opt::Arg *arg =
-          args.getLastArg(clang::driver::options::OPT_fxor_operator,
-              clang::driver::options::OPT_fno_xor_operator)) {
-    opts.features.Enable(Fortran::common::LanguageFeature::XOROperator,
-        arg->getOption().matches(clang::driver::options::OPT_fxor_operator));
-  }
+  // -f{no-}implicit-none
+  opts.features.Enable(
+      Fortran::common::LanguageFeature::ImplicitNoneTypeAlways,
+      args.hasFlag(clang::driver::options::OPT_fimplicit_none,
+          clang::driver::options::OPT_fno_implicit_none, false));
+
+  // -f{no-}backslash
+  opts.features.Enable(Fortran::common::LanguageFeature::BackslashEscapes,
+      args.hasFlag(clang::driver::options::OPT_fbackslash,
+          clang::driver::options::OPT_fno_backslash, false));
+
+  // -f{no-}logical-abbreviations
+  opts.features.Enable(Fortran::common::LanguageFeature::LogicalAbbreviations,
+      args.hasFlag(clang::driver::options::OPT_flogical_abbreviations,
+          clang::driver::options::OPT_fno_logical_abbreviations, false));
+
+  // -f{no-}xor-operator
+  opts.features.Enable(Fortran::common::LanguageFeature::XOROperator,
+      args.hasFlag(clang::driver::options::OPT_fxor_operator,
+          clang::driver::options::OPT_fno_xor_operator, false));
+
   if (args.hasArg(
           clang::driver::options::OPT_falternative_parameter_statement)) {
     opts.features.Enable(Fortran::common::LanguageFeature::OldStyleParameter);
@@ -406,11 +401,10 @@ static bool parseSemaArgs(CompilerInvocation &res, llvm::opt::ArgList &args,
     res.SetModuleFileSuffix(moduleSuffix->getValue());
   }
 
-  // -fno-analyzed-objects-for-unparse
-  if (args.hasArg(
-          clang::driver::options::OPT_fno_analyzed_objects_for_unparse)) {
-    res.SetUseAnalyzedObjectsForUnparse(false);
-  }
+  // -f{no-}analyzed-objects-for-unparse
+  res.SetUseAnalyzedObjectsForUnparse(
+      args.hasFlag(clang::driver::options::OPT_fanalyzed_objects_for_unparse,
+          clang::driver::options::OPT_fno_analyzed_objects_for_unparse, true));
 
   return diags.getNumErrors() == numErrorsBefore;
 }

flang/test/Driver/driver-help-hidden.f90

@@ -40,7 +40,12 @@
 ! CHECK-NEXT:                        Specify where to find the compiled intrinsic modules
 ! CHECK-NEXT: -flarge-sizes          Use INTEGER(KIND=8) for the result type in size-related intrinsics
 ! CHECK-NEXT: -flogical-abbreviations Enable logical abbreviations
-! CHECK-NEXT: -fno-color-diagnostics Disable colors in diagnostics
+! CHECK-NEXT: -fno-backslash
+! CHECK-NEXT: -fno-color-diagnostics  Disable colors in diagnostics
+! CHECK-NEXT: -fno-implicit-none
+! CHECK-NEXT: -fno-logical-abbreviations
+! CHECK-NEXT: {{[[:space:]]$}}
+! CHECK-NEXT: -fno-xor-operator
 ! CHECK-NEXT: -fopenacc              Enable OpenACC
 ! CHECK-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
 ! CHECK-NEXT: -fxor-operator         Enable .XOR. as a synonym of .NEQV.

flang/test/Driver/driver-help.f90

@@ -40,7 +40,12 @@
 ! HELP-NEXT:                        Specify where to find the compiled intrinsic modules
 ! HELP-NEXT: -flarge-sizes          Use INTEGER(KIND=8) for the result type in size-related intrinsics
 ! HELP-NEXT: -flogical-abbreviations Enable logical abbreviations
-! HELP-NEXT: -fno-color-diagnostics Disable colors in diagnostics
+! HELP-NEXT: -fno-backslash
+! HELP-NEXT: -fno-color-diagnostics  Disable colors in diagnostics
+! HELP-NEXT: -fno-implicit-none
+! HELP-NEXT: -fno-logical-abbreviations
+! HELP-NEXT: {{[[:space:]]$}}
+! HELP-NEXT: -fno-xor-operator
 ! HELP-NEXT: -fopenacc              Enable OpenACC
 ! HELP-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
 ! HELP-NEXT: -fxor-operator         Enable .XOR. as a synonym of .NEQV.
@@ -69,6 +74,8 @@
 ! HELP-FC1-NEXT: -E                     Only run the preprocessor
 ! HELP-FC1-NEXT: -falternative-parameter-statement
 ! HELP-FC1-NEXT: Enable the old style PARAMETER statement
+! HELP-FC1-NEXT: -fanalyzed-objects-for-unparse
+! HELP-FC1-NEXT: {{[[:space:]]$}}
 ! HELP-FC1-NEXT: -fbackslash            Specify that backslash in string introduces an escape character
 ! HELP-FC1-NEXT: -fdebug-dump-all       Dump symbols and the parse tree after the semantic checks
 ! HELP-FC1-NEXT: -fdebug-dump-parse-tree-no-sema
@@ -104,7 +111,12 @@
 ! HELP-FC1-NEXT: -flogical-abbreviations Enable logical abbreviations
 ! HELP-FC1-NEXT: -fno-analyzed-objects-for-unparse
 ! HELP-FC1-NEXT:                        Do not use the analyzed objects when unparsing
+! HELP-FC1-NEXT: -fno-backslash
+! HELP-FC1-NEXT: -fno-implicit-none
+! HELP-FC1-NEXT: -fno-logical-abbreviations
+! HELP-FC1-NEXT: {{[[:space:]]$}}
 ! HELP-FC1-NEXT: -fno-reformat          Dump the cooked character stream in -E mode
+! HELP-FC1-NEXT: -fno-xor-operator
 ! HELP-FC1-NEXT: -fopenacc              Enable OpenACC
 ! HELP-FC1-NEXT: -fopenmp               Parse OpenMP pragmas and generate parallel code.
 ! HELP-FC1-NEXT: -fxor-operator         Enable .XOR. as a synonym of .NEQV.