Set target platform identification variables like `APPLE` and `LINUX`
as soon as the target system is identified. This makes them available
during toolchain and binutils selection.
Fixes: #23333
All of NetBSD, FreeBSD, OpenBSD and DragonFly BSD support `$ORIGIN`,
but the last two require `-z origin` as documented at
https://lekensteyn.nl/rpath.html
The `-z origin` option causes a flag bit to be set and has no effect if
the `RPATH` does not contain expandable tokens.
Remove ancient checks left from commit f5d95fb0 (Complete rework of
makefile generators expect trouble, 2002-11-08). Modern FreeBSD and
NetBSD platforms support shared libraries. When cross-compiling the
/usr/include/dlfcn.h may not exist on the host but the toolchain still
supports shared libraries.
Ancient versions of CMake required else(), endif(), and similar block
termination commands to have arguments matching the command starting the
block. This is no longer the preferred style.
Run the following shell code:
for c in else endif endforeach endfunction endmacro endwhile; do
echo 's/\b'"$c"'\(\s*\)(.\+)/'"$c"'\1()/'
done >convert.sed &&
git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' |
egrep -z -v '^(Utilities/cm|Source/kwsys/)' |
egrep -z -v 'Tests/CMakeTests/While-Endwhile-' |
xargs -0 sed -i -f convert.sed &&
rm convert.sed
Store in new platform variables
CMAKE_${lang}_COMPILE_OPTIONS_PIC
CMAKE_${lang}_COMPILE_OPTIONS_PIE
flags for position independent code generation.
In almost all cases, this means duplication of the
CMAKE_SHARED_LIBRARY_${lang}_FLAGS for the _PIC case and using the
assumed pie equivalent for the _PIE case. Note that the GNU compiler
has supported -fPIE since 3.4 and that there is no -fPIC on GNU for
Windows or Cygwin.
There is a possibility that the _PIE variables are not correct.
However, as there is no backwards compatibility to be concerned about
(as the POSITION_INDEPENDENT_CODE property is not used anywhere yet),
the current state suffices.
Several platform-wide linker flag variables are defined in
Modules/Platform/<os>.cmake files for C and then copied by the
Modules/CMake<lang>Information.cmake file for each language.
We now use this approach for the variables
CMAKE_EXE_EXPORTS_${lang}_FLAG
CMAKE_SHARED_LIBRARY_SONAME_${lang}_FLAG
CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS
to avoid duplication for multiple languages in each platform file.
