Commit Graph

9 Commits

Author SHA1 Message Date
Stephen Kelly 0dfe395e3c Features: Add COMPILE_FEATURES generator expression.
Allow setting build properties based on the features available
for a target.  The availability of features is determined at
generate-time by evaluating the link implementation.

Ensure that the <LANG>_STANDARD determined while evaluating
COMPILE_FEATURES in the link implementation is not lower than that
provided by the INTERFACE of the link implementation.  This is
similar to handling of transitive properties such as
POSITION_INDEPENDENT_CODE.
2014-05-21 17:22:32 +02:00
Stephen Kelly e0890d03a4 Features: Extend concept to C language.
Add properties and variables corresponding to CXX equivalents.

Add features for c_function_prototypes (C90), c_restrict (C99),
c_variadic_macros (C99) and c_static_assert (C11). This feature
set can be extended later.

Add a <PREFIX>_RESTRICT symbol define to WriteCompilerDetectionHeader
to conditionally represent the c_restrict feature.
2014-05-15 00:15:18 +02:00
Stephen Kelly eb638c75cc Tests: Make CompileFeatures feature list lang-specific. 2014-05-10 13:05:46 +02:00
Stephen Kelly 205215fb8a cmTarget: Add CXX_STANDARD_REQUIRED to control decay. 2014-05-07 12:17:49 +02:00
Stephen Kelly 8d0b1ccac1 Features: FATAL_ERROR on compilers with no recorded features.
Users of the new target_compile_features command are expected to
check the existence of the CMAKE_CXX_COMPILE_FEATURES variable before
attempting to use it to require features.
2014-04-17 16:20:50 +02:00
Stephen Kelly 8ed59fc207 Add target_compile_features command.
This can be used to set the compiler features required by particular
targets. An error is issued at CMake time if the compiler does not
support the required feature. If a language dialect flag is required
by the features used, that will be added automatically.

Base the target_compile_features command on cmTargetPropCommandBase. This
gives us 'free' handling of IMPORTED, ALIAS, INTERFACE, non-compilable
and missing targets.
2014-04-07 18:11:18 +02:00
Stephen Kelly 5412deded1 cmTarget: Transitively evaluate compiler features.
Extend the interface of the target_compile_features command with
PUBLIC and INTERFACE keywords. Populate the INTERFACE_COMPILER_FEATURES
target property if they are set. Consume the INTERFACE_COMPILER_FEATURES
target property from linked dependent targets to determine the final
required compiler features and the compile flag, if needed.

Use the same pattern of origin-debugging which is used for other
build properties.
2014-04-07 18:11:18 +02:00
Stephen Kelly baff44345c cmTarget: Allow populating COMPILE_FEATURES using generator expressions.
Delay validation of the content as a feature if it contains a
generator expression. It will be checked again at generate-time
after evaluation.
2014-04-07 18:11:18 +02:00
Stephen Kelly f97bf4370c Features: Add cxx_auto_type.
Record the availability of this feature for GNU 4.8 on (UNIX AND
NOT APPLE) only.  In the future, availability can be recorded for
earlier GNU, for other platforms and for other compilers. Initially
the affected configurations are as restricted as possible to allow
for easy testing while extending the features vector in only one
dimension.

The error message when using the set_property API directly is not
very good, but follow up commits will provide origin debugging of
the property and a target_compile_features command which will
provide a configure-time backtrace when possible.
2014-04-07 18:11:18 +02:00