https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100695
--- Comment #2 from Tobias Burnus ---
Created attachment 53233
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53233=edit
Patch which does not work (segfault during self test) – but maybe it gives an
idea how to solve the issue
I think there are multiple issues:
(a) '%T' does not accept %qT but there is still an error for using %<%T%>
(b) Using %qT should be accepted. This implies both the addition of "q" to
c-family/c-format.cc's gcc_dump_printf_char_table
to permit it.
(c) Using %qT kind of works - but does not actually print the quotes.
(cf. comment 1)
That's because of how it is processed. In pretty-print.cc pp_format:
if (quote)
pp_begin_quote (pp, pp_show_color (pp));
...
ok = pp_format_decoder (pp) (pp, text, p,
precision, wide, plus, hash, ,
formatters[argno]);
...
if (quote)
pp_end_quote (pp, pp_show_color (pp));
This works well, if the item - is processed directly.
For instance, tree-diagnostic.cc's default_tree_printer just does:
case 'E':
...
pp_identifier (pp, IDENTIFIER_POINTER (t));
return true;
However, in dumpfile.cc's dump_pretty_printer::decode_format there is no direct
output but the %qT processing is deferred (spec = 'T', buffer_ptr = "qT"):
dump_pretty_printer::decode_format (text_info *text, const char *spec,
const char **buffer_ptr)
{
/* Various format codes that imply making an optinfo_item and stashed it
for later use (to capture metadata, rather than plain text). */
...
case 'T':
{
tree t = va_arg (*text->args_ptr, tree);
/* Make an item for the tree, and stash it. */
optinfo_item *item = make_item_for_dump_generic_expr (t, TDF_SLIM);
stash_item (buffer_ptr, item);
return true;
And the 'stash_item' effectively undoes the quote. For %<...%>, those are
processed separately, such that 'decode_format' only processes '%T' and the
quotes are retained.
Thus, one way would be to 'obstack_grow' - or something like that to "split"
'q' ... 'T' in %qT. Or to handle somehow the
pp_buffer(pp)
in dump_pretty_printer::decode_format