These policies are triggered by the use of a particular compiler rather
than outdated CMake code in a project. Avoid warning in every project
that enables a language by not displaying the policy warning by default.
Add variable CMAKE_POLICY_WARNING_CMP<NNNN> to control the warning
explicitly; otherwise enable the warning with --debug-output or --trace.
This breaks with strict policy convention because it does not provide
developers with any warning about the behavior change by default.
Existing projects will continue to build without a warning or change in
behavior. When a developer changes the minimum required version of
CMake in a project to a sufficiently high value (3.0), the project will
suddenly get the new compiler id and may break, but at least the
breakage comes with a change to the project rather than the version of
CMake used to build it.
Breaking strict policy convention is worthwhile in this case because
very few projects will be affected by the behavior change but every
project would have to see the warning if it were enabled by default.
Use the clang RemoveCStrCalls tool to automatically migrate the
code. This was only run on linux, so does not have any positive or
negative effect on other platforms.
Casts from std::string -> cmStdString were high on the list of things
taking up time. Avoid such implicit casts across function calls by just
using std::string everywhere.
The comment that the symbol name is too long is no longer relevant since
modern debuggers alias the templates anyways and the size is a
non-issue since the underlying methods are generated since it's
inherited.
When running CMake from the build tree the CMAKE_ROOT is the
entire source tree. Fix the CMP0017 check to be specific to
the Modules/ directory under CMAKE_ROOT so that Tests/ does
not count. Fix the FindPackageTest modules to include FPHSA
by full path from CMAKE_ROOT so that they do not include the
local FPHSA which reports an error meant to test that CMP0017
works.
Define a new 'CMAKE_CONFIGURE_DEPENDS' directory property that projects
can use to specify input files to the CMake configuration process.
Extend the RunCMake.Configure test to verify that the build system
re-runs CMake when this input changes.
Most callers already have a std::string, on which they called c_str() to pass it
into these methods, which internally converted it back to std::string. Pass a
std::string directly to these methods now, avoiding all these conversions.
Those methods that only pass in a const char* will get the conversion to
std::string now only once.