Re: [PATCH v5] ld: Make archive member file extension comparisons case insensitive when cross compiling too

[Jan Beulich <jbeulich@suse.com>]

On 24.08.2022 12:04, Martin Storsjö wrote:
> @@ -1857,7 +1880,7 @@ gld${EMULATION_NAME}_unrecognized_file (lang_input_statement_type *entry ATTRIBU
>  #ifdef DLL_SUPPORT
>    const char *ext = entry->filename + strlen (entry->filename) - 4;
>  
> -  if (filename_cmp (ext, ".def") == 0 || filename_cmp (ext, ".DEF") == 0)
> +  if (fileext_cmp (ext, "def") == 0)
>      {
>        pe_def_file = def_file_parse (entry->filename, pe_def_file);
>  

The pre-existing code doesn't look safe here (and I did overlook the
lack of strrchr() here when writing my earlier reply). There's a
buffer underflow for file names shorter than 4 characters.

And I'm inclined to say that ".def" on its own isn't a .def-file, but
a file without any extension. (This applies to all other cases you
change as well.)

If I was touching all of this anyway, I'd be inclined to address both
issues as a "side effect" of the patch. But of course it's not a
requirement; it can easily be a separate, later patch. Or you could
also elect to switch to using strrchr() here (thus allowing code to
be dropped from the new function with callers all adding 1 to the
pointer they pass), but leave the "not really an extension" part
alone.

Jan