[LLD][ELF] Mention contents of reproduce archive and add help description.

[peter.smith]

Summary

Building on D60557 mention the name of the linker generated contents of the reproduce archive, response.txt and version.txt. Also write a shorter description in the ld.lld --help that is closer to the documentation.

[MaskRay]

Nice!

lld/trunk/ELF/Options.td

def pop_state: F<"pop-state">,
   HelpText<"Undo the effect of -push-state">;
 
 def push_state: F<"push-state">,
   HelpText<"Save the current state of -as-needed, -static and -whole-archive">;
 
 def print_map: F<"print-map">,
   HelpText<"Print a link map to the standard output">;
 
-defm reproduce: Eq<"reproduce", "Dump linker invocation and input files for debugging">;
+defm reproduce: Eq<"reproduce", "Write a tar file containing input files and command line options to reproduce link">;
 
 defm rpath: Eq<"rpath", "Add a DT_RUNPATH to the output">;
 
 def relocatable: F<"relocatable">, HelpText<"Create relocatable object file">;
 
 defm retain_symbols_file:
   Eq<"retain-symbols-file", "Retain only the symbols listed in the file">,
   MetaVarName<"<file>">;

lld/trunk/docs/ld.lld.1

 and
 .Fl -whole-archive.
 .It Fl -pop-state
 Undo the effect of
 .Fl -push-state.
 .It Fl -relocatable , Fl r
 Create relocatable object file.
 .It Fl -reproduce Ns = Ns Ar path
-Write a tar file containing all input files and a text file describing the link invocation to
+Write a tar file to
 .Ar path,
-so that you can easily re-run the linker with the same options and input files.
+containing all the input files needed to reproduce the link, a text file called
+response.txt containing the command line options and a text file called
+version.txt containing the output of ld.lld --version. The archive when
+unpacked can be used to re-run the linker with the same options and input files.
 .It Fl -retain-symbols-file Ns = Ns Ar file
 Retain only the symbols listed in the file.
 .It Fl -rpath Ns = Ns Ar value , Fl R Ar value
 Add a
 .Dv DT_RUNPATH
 to the output.
 .It Fl -rsp-quoting Ns = Ns Ar value
 Quoting style for response files.