On 10/16/2013 04:40 PM, Sergio Durigan Junior wrote:
> I had a brief chat with Keith, who updated me on this.  According to
> him, there are many more places that need to be updated.  He's already
> talking to Pierre about this, so probably my patch is not
> complete/correct.  Thus, feel free to drop it if it is the case.

Yeah, my apologies. I *thought* I had a pascal compiler installed, but I 
didn't. [Maybe I was thinking of Fortran?] In any case, my previous 
patch to pascal_lex does some really nasty things, like assigning to 
lexptr/stoken from an alloca'd block. Boo!

This patch fixes the regressions by doing what I should have done the 
first time around: it changes pascal_lex to really take const input.

There are two little sections of code, though, which violate const-ness 
of the input, and I've removed those, since they don't seem necessary. 
[This is the two loops that deal with changing the case of `tokstart' -- 
which can easily be removed because we already have a temporary buffer 
that is used for this.]

I could not think of any reasons why pascal_lex would need to change the 
input. The only thing that came to mind was completion, and the behavior 
for that is, as far as I can tell, identical to how 7.0, 7.3, 7.4, 7.5, 
and 7.6 behave. [both case-sensitive 'on' and 'off']

[Perhaps Pierre knows? It was added here:

commit 458d424149528912ee72f6b9b9a2afd578a17715
Author: Pierre Muller <muller@ics.u-strasbg.fr>
Date:   Fri Nov 9 09:46:40 2001 +0000

     2001-11-06 Pierre Muller  <muller@ics.u-strasbg.fr>

         * p-exp.y (yylex): Only change case of expression if symbol is 
found.
         Also check for GPC standard name form.
]

In any case, IMO parsers should not be changing their input. If this 
turns out to be necessary, we should extend the API to support it.

Comments?
Keith

ChangeLog
2013-10-17  Keith Seitz  <keiths@redhat.com>

	* p-exp.y (uptok): Make first parameter const.
	(yylex): Make `tokstart' and `tokptr' const.
	Don't copy the lexer input to a temporary buffer.
	Make `p' const.
	Remove const workaround ofr parse_escape.
	Create a temporary buffer for a convenience variable instead
	of doing in-place modification of the input.
	If a match is found with a different case from the input,
	do not change the input at all.
	Use `tmp' to construct the resultant stoken instead of
	`tokstart'.