Previously we checked for this flag by parsing the version number of GCC
out of 'gcc --version', but this is not reliable because the format can
vary greatly. Now we run 'gcc -v --help' and look for '-isysroot' in
the list of options.
We also now store the result on a per-language basis in the per-compiler
info file "CMake<LANG>Compiler.cmake". This is necessary to make it
accessible from try-compile projects so that they generate correctly.
The commit "Consider link dependencies for link language" taught CMake
to propagate linker language preference from languages compiled into
libraries linked by a target. It turns out this should only be done for
some languages, such as C++, because normally the language of the
program entry point (main) should be used.
We introduce variable CMAKE_<LANG>_LINKER_PREFERENCE_PROPAGATES to tell
CMake whether a language should propagate its linker preference across
targets. Currently it is true only for C++.
This teaches CMake to detect implicit link information for C, C++, and
Fortran compilers. We detect the implicit linker search directories and
implicit linker options for UNIX-like environments using verbose output
from compiler front-ends. We store results in new variables called
CMAKE_<LANG>_IMPLICIT_LINK_LIBRARIES
CMAKE_<LANG>_IMPLICIT_LINK_DIRECTORIES
The implicit libraries can contain linker flags as well as library
names.
two-step priority (None or Prefered)
Current order: ASM 0, C 10, Fortran 20, CXX 30, Java 40
This is the same order as automake choses:
http://www.gnu.org/software/automake/manual/html_node/How-the-Linker-is-Chosen.html
This change should be backward compatible:
if there is a project using fortran and CXX, they had to set the
LINKER_LANGUAGE explicitely, otherwise cmake complained (but still generated
the project files). Explicitely setting the linker language still overrides
automatic detection.
If somebody has a custom language for cmake and the PREFERENCE starts with
"P", its changed to 100, which gives it preference over all other languages
(except the other custom languages which have also "Prefered"). "None" is
converted to 0.
Alex
second part copies the values from the cmake variables into internal maps.
So this can now be done after the compiler-specific information has been
loaded, which can now overwrite more settings.
Alex
-add a RESULT_VARIABLE to INCLUDE()
-add CMAKE_TOOLCHAIN_FILE for specifiying your (potentially crosscompiling) toolchain
-have TRY_RUN() complain if you try to use it in crosscompiling mode (which were compiled but cannot run on this system)
-use CMAKE_EXECUTABLE_SUFFIX in TRY_RUN(), probably TRY_RUN won't be able to
run the executables if they have a different suffix because they are
probably crosscompiled, but nevertheless it should be able to find them
-make several cmake variables presettable by the user: CMAKE_C/CXX_COMPILER, CMAKE_C/CXX_OUTPUT_EXTENSION, CMAKE_SYSTEM_NAME, CMAKE_SYSTEM_INFO_FILE
-support prefix for GNU toolchains (arm-elf-gcc, arm-elf-ar, arm-elf-strip etc.)
-move ranlib on OSX from the file command to a command in executed in cmake_install.cmake
-add support for stripping during install in cmake_install.cmake
-split out cl.cmake from Windows-cl.cmake, first (very incomplete) step to support MS crosscompiling tools
-remove stdio.h from the simple C program which checks if the compiler works, since this may not exist for some embedded platforms
-create a new CMakeFindBinUtils.cmake which collects the search fro ar, ranlib, strip, ld, link, install_name_tool and other tools like these
-add support for CMAKE_FIND_ROOT_PATH for all FIND_XXX commands, which is a
list of directories which will be prepended to all search directories, right
now as a cmake variable, turning it into a global cmake property may need
some more work
-remove cmTestTestHandler::TryExecutable(), it's unused
-split cmFileCommand::HandleInstall() into slightly smaller functions
Alex
Brad King
Alexander Neundorf
Bill Hoffman