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Re: [expr] [patch] Fix "break expr if (cond)" regression

>>>>> "Jan" == Jan Kratochvil <> writes:

Jan> I do not fully agree with my patch but I also do not fully agree
Jan> with the former patch, maybe bison should be used to parse the
Jan> expression, but rather someone (Tom? unaware) said that "break E
Jan> [thread T] [if C]" should be rather changed to the more
Jan> parseable+standardized "break [-thread T] [-if C] E" so that these
Jan> expression parsing difficulties would be present only as a backward
Jan> compatibility and do not need to supersede the former
Jan> functionality.

In the end gdb went the other route, of making "thread" special in the
lexer -- but with a twist:

  /* For the same reason (breakpoint conditions), "thread N"
     terminates the expression.  "thread" could be an identifier, but
     an identifier is never followed by a number without intervening
     punctuation.  "task" is similar.  Handle abbreviations of these,
     similarly to breakpoint.c:find_condition_and_thread.  */
      if (*p >= '0' && *p <= '9')
	return 0;

I think linespecs would be more maintainable if we came up with a
grammar for them and implemented them using bison (or any parser
generator), but I don't know if that is even possible while preserving


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