[MinGW] Restructure Options.td to use multiclass where sensible. NFC.

[rnk]

lgtm

lld/trunk/MinGW/Options.td

 include "llvm/Option/OptParser.td"
 
 class F<string name>: Flag<["--", "-"], name>;
 class J<string name>: Joined<["--", "-"], name>;
 class S<string name>: Separate<["--", "-"], name>;
 
+multiclass Eq<string name, string help> {
+  def NAME: Separate<["--", "-"], name>;
+  def NAME # _eq: Joined<["--", "-"], name # "=">, Alias<!cast<Separate>(NAME)>,
+    HelpText<help>;
+}
+
+multiclass EqLong<string name, string help> {
+  def NAME: Separate<["--"], name>;
+  def NAME # _eq: Joined<["--"], name # "=">, Alias<!cast<Separate>(NAME)>,
+    HelpText<help>;
+}
+
 def L: JoinedOrSeparate<["-"], "L">, MetaVarName<"<dir>">,
   HelpText<"Add a directory to the library search path">;
 def Bdynamic: F<"Bdynamic">, HelpText<"Link against shared libraries">;
 def Bstatic: F<"Bstatic">, HelpText<"Do not link against shared libraries">;
 def dynamicbase: F<"dynamicbase">, HelpText<"Enable ASLR">;
 def entry: S<"entry">, MetaVarName<"<entry>">,
   HelpText<"Name of entry point symbol">;
 def exclude_all_symbols: F<"exclude-all-symbols">,
     HelpText<"Don't automatically export any symbols">;
 def export_all_symbols: F<"export-all-symbols">,
     HelpText<"Export all symbols even if a def file or dllexport attributes are used">;
 def gc_sections: F<"gc-sections">, HelpText<"Remove unused sections">;
 def help: F<"help">, HelpText<"Print option help">;
 def icf: J<"icf=">, HelpText<"Identical code folding">;
 def image_base: S<"image-base">, HelpText<"Base address of the program">;
 def insert_timestamp: F<"insert-timestamp">,
     HelpText<"Include PE header timestamp">;
 def kill_at: F<"kill-at">, HelpText<"Remove @n from exported symbols">;
 def l: JoinedOrSeparate<["-"], "l">, MetaVarName<"<libName>">,
   HelpText<"Root name of library to use">;
 def m: JoinedOrSeparate<["-"], "m">, HelpText<"Set target emulation">;
-def major_os_version: Separate<["--"], "major-os-version">,
-    HelpText<"Set the OS and subsystem major version">;
-def major_os_version_eq: Joined<["--"], "major-os-version=">,
-    Alias<major_os_version>;
-def major_subsystem_version: Separate<["--"], "major-subsystem-version">,
-    HelpText<"Set the OS and subsystem major version">;
-def major_subsystem_version_eq: Joined<["--"], "major-subsystem-version=">,
-    Alias<major_subsystem_version>;
-def map: S<"Map">, HelpText<"Output a linker map">;
-def map_eq: J<"Map=">, Alias<map>;
-def minor_os_version: Separate<["--"], "minor-os-version">,
-    HelpText<"Set the OS and subsystem minor version">;
-def minor_os_version_eq: Joined<["--"], "minor-os-version=">,
-    Alias<minor_os_version>;
-def minor_subsystem_version: Separate<["--"], "minor-subsystem-version">,
-    HelpText<"Set the OS and subsystem minor version">;
-def minor_subsystem_version_eq: Joined<["--"], "minor-subsystem-version=">,
-    Alias<minor_subsystem_version>;
+defm major_os_version: EqLong<"major-os-version",
+     "Set the OS and subsystem major version">;
+defm major_subsystem_version: EqLong<"major-subsystem-version",
+     "Set the OS and subsystem major version">;
+defm map: Eq<"Map", "Output a linker map">;
+defm minor_os_version: EqLong<"minor-os-version",
+     "Set the OS and subsystem minor version">;
+defm minor_subsystem_version: EqLong<"minor-subsystem-version",
+     "Set the OS and subsystem minor version">;
 def no_insert_timestamp: F<"no-insert-timestamp">,
     HelpText<"Don't include PE header timestamp">;
 def no_whole_archive: F<"no-whole-archive">,
     HelpText<"No longer include all object files for following archives">;
 def large_address_aware: Flag<["--"], "large-address-aware">,
     HelpText<"Enable large addresses">;
 def no_gc_sections: F<"no-gc-sections">, HelpText<"Don't remove unused sections">;
 def o: JoinedOrSeparate<["-"], "o">, MetaVarName<"<path>">,
   HelpText<"Path to file to write output">;
-def out_implib: Separate<["--"], "out-implib">, HelpText<"Import library name">;
-def out_implib_eq: Joined<["--"], "out-implib=">, Alias<out_implib>;
+defm out_implib: EqLong<"out-implib", "Import library name">;
 def output_def: S<"output-def">, HelpText<"Output def file">;
 def shared: F<"shared">, HelpText<"Build a shared object">;
-def subs: S<"subsystem">, HelpText<"Specify subsystem">;
-def subs_eq: J<"subsystem=">, Alias<subs>;
+defm subs: Eq<"subsystem", "Specify subsystem">;
 def stack: S<"stack">;
 def strip_all: F<"strip-all">,
     HelpText<"Omit all symbol information from the output binary">;
 def strip_debug: F<"strip-debug">,
     HelpText<"Omit all debug information, but keep symbol information">;
-def undefined: S<"u">,
-    HelpText<"Include symbol in the link, if available">;
-def undefined_long: S<"undefined">, Alias<undefined>;
-def undefined_eq: J<"undefined=">, Alias<undefined>;
+defm undefined: Eq<"undefined", "Include symbol in the link, if available">;
 def whole_archive: F<"whole-archive">,
     HelpText<"Include all object files for following archives">;
 def v: Flag<["-"], "v">, HelpText<"Display the version number">;
 def verbose: F<"verbose">, HelpText<"Verbose mode">;
 def version: F<"version">, HelpText<"Display the version number and exit">;
-def require_defined: S<"require-defined">,
-    HelpText<"Force symbol to be added to symbol table as an undefined one">;
-def require_defined_eq: J<"require-defined=">, Alias<require_defined>;
+defm require_defined: Eq<"require-defined",
+     "Force symbol to be added to symbol table as an undefined one">;
 
 // LLD specific options
 def _HASH_HASH_HASH : Flag<["-"], "###">,
     HelpText<"Print (but do not run) the commands to run for this compilation">;
 def appcontainer: F<"appcontainer">, HelpText<"Set the appcontainer flag in the executable">;
-def delayload: S<"delayload">, HelpText<"DLL to load only on demand">;
-def delayload_eq: J<"delayload=">, Alias<delayload>;
+defm delayload: Eq<"delayload", "DLL to load only on demand">;
 def mllvm: S<"mllvm">;
-def pdb: S<"pdb">, HelpText<"Output PDB debug info file, chosen implicitly if the argument is empty">;
-def pdb_eq: J<"pdb=">, Alias<pdb>;
+defm pdb: Eq<"pdb", "Output PDB debug info file, chosen implicitly if the argument is empty">;
 def Xlink : J<"Xlink=">, MetaVarName<"<arg>">,
     HelpText<"Pass <arg> to the COFF linker">;
 
 // Alias
 def alias_entry_e: JoinedOrSeparate<["-"], "e">, Alias<entry>;
 def alias_strip_s: Flag<["-"], "s">, Alias<strip_all>;
 def alias_strip_S: Flag<["-"], "S">, Alias<strip_debug>;
+def alias_undefined_u: S<"u">, Alias<undefined>;
 
 // Ignored options
 def: Joined<["-"], "O">;
 def: F<"build-id">;
 def: F<"disable-auto-image-base">;
 def: F<"enable-auto-image-base">;
 def: F<"enable-auto-import">, HelpText<"Ignored; listed for libtool compatibility">;
 def: F<"end-group">;