[lld-macho][NFC] Add some new version options, plus a new option group for versions

[gkm]

Summary

Add some options present in ld64 but absent here: -tvos_version_min, watchos_version_min, bridgeos_version_min, and driverkit_version_min.
For sake of organization in the --help output, coalesce all version-control options into a new option group.

[compnerd]

This adds additional options while also adding a group for the versions. Is there a reason for the group to be added? Can you please either remove the newly added options or adjust the commit message? I think that there should be some reasoning given for the version group creation (at least, it isn't clear to me why the group is helpful/necessary, unlike in clang where the group can be used to silence warnings).

[smeenai]

We've been pretty liberal with our use of option groups, mostly to organize the help text. I agree that the commit message should reflect that there's some new version options being added as well (tvos, watchos, bridgeos, and driverkit, if I'm reading the diff right).

[compnerd]

Sure, but if the reason for the group is to add structure to the help output, I think that is a reasonable thing to state in the commit message. The other options are ... well, either not meant to be part of the commit as per the commit message or the commit message should be updated to indicate that they are being added (and why they are part of structuring the help output, assuming that is the reason for the group). The changes requested are requests for clarification :)

[gkm]

@compnerd, I updated the title and summary as requested.

[int3]

lld/MachO/Options.td

235

"version control" makes me think of, well, git and hg... how about "target version"?

273

nit: usable is the more common spelling

[compnerd]

+1 to @int3's suggestion about the help text.

[int3]

lld/MachO/Options.td

235

seems like you missed this

lld/MachO/Options.td

 def no_order_inits : Flag<["-"], "no_order_inits">,
      HelpText<"Disable default reordering of initializer and terminator functions">,
      Flags<[HelpHidden]>,
      Group<grp_opts>;
 def no_order_data : Flag<["-"], "no_order_data">,
      HelpText<"Disable default reordering of global data accessed at launch time">,
      Flags<[HelpHidden]>,
      Group<grp_opts>;
+def image_base : Separate<["-"], "image_base">,
+     MetaVarName<"<address>">,
+     HelpText<"Preferred hex load address for a dylib or bundle.">,
+     Flags<[HelpHidden]>,
+     Group<grp_opts>;
+def seg1addr : Separate<["-"], "seg1addr">,
+     MetaVarName<"<address>">,
+     Alias<image_base>,
+     HelpText<"Alias for -image_base">,
+     Flags<[HelpHidden]>,
+     Group<grp_opts>;
+def no_implicit_dylibs : Flag<["-"], "no_implicit_dylibs">,
+     HelpText<"Do not optimize public dylib transitive symbol references">,
+     Group<grp_opts>;
+def exported_symbols_order : Separate<["-"], "exported_symbols_order">,
+     MetaVarName<"<file>">,
+     HelpText<"Specify frequently-used symbols in <file> to optimize symbol exports">,
+     Flags<[HelpHidden]>,
+     Group<grp_opts>;
+def no_zero_fill_sections : Flag<["-"], "no_zero_fill_sections">,
+     HelpText<"Explicitly store zeroed data in the final image">,
+     Flags<[HelpHidden]>,
+     Group<grp_opts>;
+def merge_zero_fill_sections : Flag<["-"], "merge_zero_fill_sections">,
+     HelpText<"Merge all zeroed data into the __zerofill section">,
+     Flags<[HelpHidden]>,
+     Group<grp_opts>;
+def no_branch_islands : Flag<["-"], "no_branch_islands">,
+     HelpText<"Disable infra for branches beyond the maximum branch distance.">,
+     Flags<[HelpHidden]>,
+     Group<grp_opts>;
+
+def grp_version : OptionGroup<"version">, HelpText<"VERSION CONTROL">;
+
 def platform_version : MultiArg<["-"], "platform_version", 3>,
      MetaVarName<"<platform> <min_version> <sdk_version>">,
      HelpText<"Platform (e.g., macos, ios, tvos, watchos, bridgeos, mac-catalyst, ios-sim, tvos-sim, watchos-sim, driverkit) and version numbers">,
-     Group<grp_opts>;
+     Group<grp_version>;
 def sdk_version : Separate<["-"], "sdk_version">,
      HelpText<"This option is undocumented in ld64">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
+     Group<grp_version>;
 def macos_version_min : Separate<["-"], "macos_version_min">,
      MetaVarName<"<version>">,
      HelpText<"Oldest macOS version for which linked output is useable">,
-     Flags<[HelpHidden]>,
-     Group<grp_opts>;
+     Group<grp_version>;
 def macosx_version_min : Separate<["-"], "macosx_version_min">,
      MetaVarName<"<version>">,
      Alias<macos_version_min>,
      HelpText<"Alias for -macos_version_min">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
+     Group<grp_version>;
 def ios_version_min : Separate<["-"], "ios_version_min">,
      MetaVarName<"<version>">,
      HelpText<"Oldest iOS version for which linked output is useable">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
+     Group<grp_version>;
 def ios_simulator_version_min : Separate<["-"], "ios_simulator_version_min">,
      MetaVarName<"<version>">,
      HelpText<"Oldest iOS simulator version for which linked output is useable">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
+     Group<grp_version>;
 def iphoneos_version_min : Separate<["-"], "iphoneos_version_min">,
      MetaVarName<"<version>">,
      Alias<ios_version_min>,
      HelpText<"Alias for -ios_version_min">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
-def image_base : Separate<["-"], "image_base">,
-     MetaVarName<"<address>">,
-     HelpText<"Preferred hex load address for a dylib or bundle.">,
+     Group<grp_version>;
+def maccatalyst_version_min : Separate<["-"], "maccatalyst_version_min">,
+     MetaVarName<"<version>">,
+     HelpText<"Oldest MacCatalyst version for which linked output is useable">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
-def seg1addr : Separate<["-"], "seg1addr">,
-     MetaVarName<"<address>">,
-     Alias<image_base>,
-     HelpText<"Alias for -image_base">,
+     Group<grp_version>;
+def iosmac_version_min : Separate<["-"], "iosmac_version_min">,
+     MetaVarName<"<version>">,
+     Alias<maccatalyst_version_min>,
+     HelpText<"Alias for -maccatalyst_version_min">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
-def no_implicit_dylibs : Flag<["-"], "no_implicit_dylibs">,
-     HelpText<"Do not optimize public dylib transitive symbol references">,
-     Group<grp_opts>;
-def exported_symbols_order : Separate<["-"], "exported_symbols_order">,
-     MetaVarName<"<file>">,
-     HelpText<"Specify frequently-used symbols in <file> to optimize symbol exports">,
+     Group<grp_version>;
+def uikitformac_version_min : Separate<["-"], "uikitformac_version_min">,
+     MetaVarName<"<version>">,
+     Alias<maccatalyst_version_min>,
+     HelpText<"Alias for -maccatalyst_version_min">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
-def no_zero_fill_sections : Flag<["-"], "no_zero_fill_sections">,
-     HelpText<"Explicitly store zeroed data in the final image">,
+     Group<grp_version>;
+def tvos_version_min : Separate<["-"], "tvos_version_min">,
+     MetaVarName<"<version>">,
+     HelpText<"Oldest tvOS version for which linked output is useable">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
-def merge_zero_fill_sections : Flag<["-"], "merge_zero_fill_sections">,
-     HelpText<"Merge all zeroed data into the __zerofill section">,
+     Group<grp_version>;
+def watchos_version_min : Separate<["-"], "watchos_version_min">,
+     MetaVarName<"<version>">,
+     HelpText<"Oldest watchOS version for which linked output is useable">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
-def no_branch_islands : Flag<["-"], "no_branch_islands">,
-     HelpText<"Disable infra for branches beyond the maximum branch distance.">,
+     Group<grp_version>;
+def bridgeos_version_min : Separate<["-"], "bridgeos_version_min">,
+     MetaVarName<"<version>">,
+     HelpText<"Oldest bridgeOS version for which linked output is useable">,
      Flags<[HelpHidden]>,
-     Group<grp_opts>;
+     Group<grp_version>;
+def driverkit_version_min : Separate<["-"], "driverkit_version_min">,
+     MetaVarName<"<version>">,
+     HelpText<"Oldest DriverKit version for which linked output is useable">,
+     Flags<[HelpHidden]>,
+     Group<grp_version>;
 
 def grp_dylib : OptionGroup<"dylib">, HelpText<"DYNAMIC LIBRARIES (DYLIB)">;
 
 def install_name : Separate<["-"], "install_name">,
      MetaVarName<"<name>">,
      HelpText<"Set an internal install path in a dylib">,
      Group<grp_dylib>;
 def dylib_install_name : Separate<["-"], "dylib_install_name">,

 def no_kext_objects : Flag<["-"], "no_kext_objects">,
      HelpText<"This option is undocumented in ld64">,
      Flags<[HelpHidden]>,
      Group<grp_undocumented>;
 def kexts_use_stubs : Flag<["-"], "kexts_use_stubs">,
      HelpText<"This option is undocumented in ld64">,
      Flags<[HelpHidden]>,
      Group<grp_undocumented>;
-def maccatalyst_version_min : Flag<["-"], "maccatalyst_version_min">,
-     HelpText<"This option is undocumented in ld64">,
-     Flags<[HelpHidden]>,
-     Group<grp_undocumented>;
-def iosmac_version_min : Flag<["-"], "iosmac_version_min">,
-     Alias<maccatalyst_version_min>,
-     HelpText<"Alias for -maccatalyst_version_min">,
-     Flags<[HelpHidden]>,
-     Group<grp_undocumented>;
-def uikitformac_version_min : Flag<["-"], "uikitformac_version_min">,
-     Alias<maccatalyst_version_min>,
-     HelpText<"Alias for -maccatalyst_version_min">,
-     Flags<[HelpHidden]>,
-     Group<grp_undocumented>;
 def no_compact_unwind : Flag<["-"], "no_compact_unwind">,
      HelpText<"This option is undocumented in ld64">,
      Flags<[HelpHidden]>,
      Group<grp_undocumented>;
 def no_dtrace_dof : Flag<["-"], "no_dtrace_dof">,
      HelpText<"This option is undocumented in ld64">,
      Flags<[HelpHidden]>,
      Group<grp_undocumented>;