ui_out format strings for fields and styles (Re: [PATCH] Style "pwd" output)

[Tom Tromey]

>>>>> "Pedro" == Pedro Alves <palves@redhat.com> writes:

Pedro> Also, since gcc expects a pointer for %p, and we want to pass an
Pedro> enum for the style, I added a small pointer-wrapper hack -- see the
Pedro> ptr function.  Yay C++.

We could just remove the enum, move to passing pointers everywhere, and
convert the *_style objects to be pointers.  This would streamline
things a bit; and we could use nullptr to mean "keep the default".

Another option would be to just add a ptr method to the _style objects,
so instead of ui_out_style_kind::VARIABLE you'd write variable_style.ptr ().

Pedro> I've not been paying much attention to the styling patches, so I can't
Pedro> off hand tell which places would benefit the most from this.  So I just
Pedro> grepped for _styled and replaced a couple spots.  Likely there are better
Pedro> examples.

There's my new patch and I have one more along those lines as well, but
a good existing one that was already deconstructed is in symfile.c:

	  puts_filtered (_("Reading symbols from "));
	  fputs_styled (name, file_name_style.style (), gdb_stdout);
	  puts_filtered ("...\n");

Pedro> For the seemingly common case of printing a string variable
Pedro> with a style, I'm thinking that a specific formatter would
Pedro> be better.  I'll post a follow up patch for that.

I'm interested to see it.

Tom