On 2014-02-11 23:03, Ben Boeckel wrote:
On Tue, Feb 11, 2014 at 19:16:49 -0500, Matthew Woehlke wrote:
On 2014-02-11 17:54, Ben Boeckel wrote:
Parsing in CMake is split into separate sections: the part which parses
the lines into CMake's command calls and the part which expands
variables (which is why "${cmd}(${args})" isn't allowed).
Right; I'd figured that much out on my own, and my own parser AFAICT
operates in a similar manner to CMake itself... it doesn't try to
tokenize variable substitutions (I didn't need that, and it would
have made the API non-trivially more complex), although it does choke
if it seems things like '${foo\n'. From what I can tell, the CMake
command parsing pass does also?
Probably worth a test. The new parser will see:
${foo
}
and happily lookup the "foo\n" variable. The old parser may have choked.
Hmm... that's an interesting and perhaps undesirable behavior change.
AFAICT, the old parser, on encountering a substitution ('${', '@',
'$ENV{', '$CACHE{'), would consume '[[:alnum:]+-._/]' until it found a
matching '}' or '@'. If it found '@' or '$' it would try to consume the
substitution according to the same rules. So yes, the old parser does
reject '${foo\n}' (also '${foo~}', etc.). (Did you check that it isn't
the first stage parser that rejects these?)
As an exception to the above, spaces are allowed inside '$ENV{}' (and
maybe '$CACHE{}'?)... (Interestingly, bash won't let you set such an
environment variable... though /usr/bin/env will...)
FWIW, variables named as such can still come in through CMakeCache.txt
and probably the command line as well, so maybe there's some value here.
If it's wanted, I can tighten up the new implementation (it's also the
perfect release version to start rejecting junk like ';' or ' ' in
variable names, but it is probably too late in the release cycle at this
point).
Yeah... I have definitely wanted that (rejecting setting variables that
don't match the above rules) before :-).
I think I even mentioned that at some point as 'things I'd like to see
in 3.0'.
--
Matthew
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