There are four in-tree target architectures that already use %|.
I think
it would be better if you made these new escapes target-specific.
Escaped curly braces cannot be target-specific since
do_assembler_dialects() in final.c ignores any % and considers '{' and
'}' to be alternative delimeters.
There are two parts to it: the actual print_operand thing, that I say
should be target-specific, since some targets already use those
characters
to mean different things; and of course the assembler dialects code
needs
to be fixed to not choke on escaped versions of the characters it is
looking for. I say you can do this second thing without special-casing
{ | }, making it more generic and cleaner and simpler.
For the logic to find the end of an alternative, you can simply
always
skip over the next char after any percent sign (well, check for
end of
string, of course); there is no need to count percent signs.
That would not be a general approach. %% stands for printing percent
sign, so in assembler string "{%%}" closing curly brace should be
handled as the end of an alternative, though it follows a percent
sign.
The second % is skipped over.
Segher
