On 2014-02-21 16:00, Ben Boeckel wrote:
On Fri, Feb 21, 2014 at 15:34:44 -0500, Matthew Woehlke wrote:
On 2014-02-21 14:51, Ben Boeckel wrote:
If I made a branch which warned when implicit expansion was done, would
folks be willing to run it over various codebases to see how annoying it
would be to just remove it altogether?
To be clear, are we talking about in the case of e.g. STREQUAL, or
*ever*? Because I'm sure breaking 'if(Pkg_FOUND)' would be very, very
bad :-).
I'd be a little suspicious of even the former; I know at least in my
case, greater understanding of implicit expansion leads to greater
*reliance* on it as a guard against unintended expansion (i.e. 'if
(FOO STREQUAL "...")' instead of 'if ("${FOO}" STREQUAL "...")').
Agreed. Which is why I'd like to know how much code would actually need
to change (since upgrading code to use the new policy would make older
CMake versions do the wrong thing since they'll dereference the value
now).
Even without a branch, I'll risk stating that requiring 'if(FOO)' to
become 'if(${FOO})' is not likely to go over well :-). (If nothing else,
I'll go ahead and object to such a change.) Probably implicit expansion
should be allowed anywhere the user doesn't think of the arguments as
strings, e.g. if(LESS), if(VERSION_LESS), etc., i.e. everything *except*
the string and regex flavors.
(Loosely related: if variable names were sane, it would at least be
safe to write e.g. 'if ("#${FOO}" STREQUAL "#...")'. But alas,
'#${FOO}' might still be the name of a variable.)
You could probably stick some sort of validator in front of the variable
map storage. I'd recommend also doing it on queries as an AUTHOR_WARNING
as well.
The same validator could also reject e.g. "TRUE" :-).
--
Matthew
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