On 29-Mar-16 21:24, Brad King wrote:
On 03/29/2016 09:09 AM, Ruslan Baratov wrote:
As a general note obviously I've used another approach because I decide
to create CMake module which can be used with regular CMake versions :)
Of course implementing this in CMake "from the box" is best.
Are we talking about levels only or about control of exact kind of
warnings too (like `-Wswitch`/`-wswitch`/`-Werror=switch`)?
At a minimum we should support levels (e.g. all, default, none) that
are generic enough to have mappings to flags on every compiler. Later
one could consider more granular switches with enumerated options that
may not all have flags on every compiler.
OTOH many such switches are
so specific that they should not be abstracted and can instead be
added to COMPILE_OPTIONS with a $<C_COMPILER_ID:...> genex guard.
What about generating nothing for such cases? E.g. code:
try {
}
catch (...) {
}
produce "catch-semantic-changed" warning on MSVC but it's okay for
Clang. So we can add `/w4571` for MSVC and nothing for other compilers.
I think these warning properties should perhaps be done as usage
requirements with propagation through INTERFACE_* properties. I'd
need to see some example use cases spelled out though.
But not if target is installed. It will be quite inconvenient if 3rd
party package add some flags to local targets. Is it possible to support
it from the box? Requirements are handy when we are talking about
different code generated with different compile flags. Warnings have
different nature. Fact that we are using `-Wall` or not using `-Wall`
doesn't change final binary or affect compatibility.
Once such directory/target properties are available then we could look
at making them take over the role of providing default warning flags
instead of putting them in the CMAKE_<LANG>_FLAGS* variables. That may
need a policy as you pointed out earlier.
-Brad
Great.
What about this:
compile_warnings # modify directory properties
target_compile_warnings # modify target properties
sources_compile_warnings # modify source properties
Same API for all:
*_compile_warnings(<global/target/source> DISABLE <warning-id>
ENABLE <warning-id> TREAT_AS_ERROR <warning-id>) # may be plus 'APPEND'
for extending instead of overwriting (?)
General warning-id's:
* ALL
* DEFAULT
* LEVEL<N>
Group warnings-id's:
* inline # MSVC: 4711 (automatic-inline), 4714 (force-not-inlined),
4710 (not-inlined), 4514 (unreferenced-inline)
* compatibility-c++98 # Clang: `-Wc++98-compat`,
`-Wc++98-compat-pedantic`
Simple warning-id examples:
* undef # Clang/GCC: `-Wunder`; MSVC: 4668
* shift-sign-overflow # Clang: `-Wshift-sign-overflow`, GCC: nothing,
MSVC: nothing
* inherits-via-dominance # Clang/GCC: nothing, MSVC: 4250
Ruslo
--
Powered by www.kitware.com
Please keep messages on-topic and check the CMake FAQ at:
http://www.cmake.org/Wiki/CMake_FAQ
Kitware offers various services to support the CMake community. For more
information on each offering, please visit:
CMake Support: http://cmake.org/cmake/help/support.html
CMake Consulting: http://cmake.org/cmake/help/consulting.html
CMake Training Courses: http://cmake.org/cmake/help/training.html
Visit other Kitware open-source projects at
http://www.kitware.com/opensource/opensource.html
Follow this link to subscribe/unsubscribe:
http://public.kitware.com/mailman/listinfo/cmake-developers
