Re: Linker diagnostics for the incorrect options .

[Nick Clifton <nickc@redhat.com>]

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Hi Fangrui,

> This is a conflict between the grouped short options syntax and single
> dash prefixed long options.
> 
> % touch an ommand ':)'
> % ld.bfd -you -can -ofcourse -use -this -Long -command -Line ':)'
> :)

he!

> For newer long options, we should encourage EXACTLY_TWO_DASHES

Definitely.

> (ld/lexsup.c). I have not seen grouped short options in a very large
> code base and FreeBSD.
> Maybe we can deprecate grouped short options syntax for ld.

I like this idea.  How about the attached patch ?  With it applied I
get output like this:

  % ld -vn -non-static -e 0 -v -e2 hello.o
  GNU ld (GNU Binutils) 2.35.50.20200923
  ld: Warning: grouped short command line options are deprecated: -vn
  ld: Error: unable to disambiguate: -non-static (did you mean --non-static ?)

  % echo $?
  1

Cheers
  Nick

[-- Attachment #2: ld-deprecate-grouped-options.patch --]
[-- Type: text/x-patch, Size: 1131 bytes --]

diff --git a/ld/lexsup.c b/ld/lexsup.c
index b8f066745f..f906508037 100644
--- a/ld/lexsup.c
+++ b/ld/lexsup.c
@@ -735,6 +735,21 @@ parse_args (unsigned argc, char **argv)
 	  optind = last_optind;
 	  optc = getopt_long (argc, argv, "-", really_longopts, &longind);
 	}
+      /* Attempt to detect grouped short options,  eg: "-non-start".
+	 Accepting such options is error prone as it is not clear if the user
+	 intended "-n -o n-start" or "--non-start".  */
+      else if (longind == 0  /* This is a short option.  */
+	       && optc > 32  /* It is a valid option.  */
+	       && optind != last_optind /* It is not a repeat of the previous option.  */
+	       && optc != argv[last_optind][1] /* The character is not the second character of argv[last_optind].  */
+	       )
+	{
+	  if (optarg)
+	    einfo (_("%F%P: Error: unable to disambiguate: %s (did you mean -%s ?)\n"),
+		   argv[last_optind], argv[last_optind]);
+	  else
+	    einfo (_("%P: Warning: grouped short command line options are deprecated: %s\n"), argv[last_optind]);
+	}
 
       if (ldemul_handle_option (optc))
 	continue;