In commit v2.8.0~395 (Implicit link info for C, CXX, and Fortran,
2009-07-23) we added a '-DCMAKE_${lang}_STANDARD_LIBRARIES=' flag to the
try_compile used to build the ABI detection project. It is needed when
detecting the implicit libraries added by the GNU compiler on Windows
(MinGW tools) to avoid contaminating the list with standard Windows
libraries. However, with MSVC we do not detect such implicit link
libraries anyway, and for some target platforms (e.g. Windows Phone) we
may need the standard libraries to link the ABI detection executable.
Drop the flag when detecting the ABI using MSVC.
The matches have already been calculated and can simply be taken from
CMAKE_MATCH_n variables. This avoids multiple compilations of the same or very
similar regular expressions.
In CMakeDetermineCompilerABI we use try_compile with the COPY_FILE
option to get a copy of the compiled binary used to detect the ABI
information. We already tolerate the case when compilation fails.
However, when compilation appears to succeed but does not produce the
expected executable the try_compile command immediately reports an error
because the COPY_FILE fails.
Tolerate COPY_FILE failure without stopping the overall configuration
process by using the try_compile COPY_FILE_ERROR option to capture the
error message. Log the full error to CMakeError.log and simply report
failure to detect the ABI as if compilation had failed.
Teach the RunCMake.Configure test to cover this case and verify that the
messages show up as expected both in stdout and in CMakeError.log.
For clang, this allows passing -target <triple> to the compiler, and
for qcc, -V<arch> using toolchain files containing something like
set(triple arm-linux-gnueabihf)
set(CMAKE_C_COMPILER "/usr/bin/clang")
set(CMAKE_C_COMPILER_TARGET ${triple})
set(CMAKE_CXX_COMPILER "/usr/bin/clang++")
set(CMAKE_CXX_COMPILER_TARGET ${triple})
or
set(arch gcc_ntoarmv7le)
set(CMAKE_C_COMPILER /opt/qnx650/host/linux/x86/usr/bin/qcc)
set(CMAKE_C_COMPILER_TARGET ${arch})
set(CMAKE_CXX_COMPILER /opt/qnx650/host/linux/x86/usr/bin/QCC)
set(CMAKE_CXX_COMPILER_TARGET ${arch})
Both clang and qcc are inherently cross compiler( driver)s.
Previously we hard-coded a list of implicit framework directories but
did not account for CMAKE_OSX_SYSROOT or for changes to the list across
OS X versions. Instead we should automatically detect the framework
directories for the active toolchain.
The parent commit added the "-Wl,-v" option to ask "ld" to print its
implicit directories. It displays a block such as:
Framework search paths:
/...
Parse this block to extract the list of framework directories.
Detection may fail on toolchains that do not list their framework
directories, such as older OS X linkers. Always treat the paths
<sdk>/Library/Frameworks
<sdk>/System/Library/Frameworks
<sdk>/Network/Library/Frameworks # Older OS X only
/System/Library/Frameworks
as implicit. Note that /System/Library/Frameworks should always be
considered implicit so that frameworks CMake finds there will not
override the SDK copies.
We detect the implicit link directories for the toolchain by adding a
flag to get verbose output from the compiler front-end while linking the
ABI detection binary. Newer OS X toolchains based on Clang do not add
the implicit link directories with -L options to their internal
invocation of "ld". Instead they use a linker that comes with the
toolchain and is already configured with the proper directories.
Add the "-Wl,-v" option to ask "ld" to print its implicit directories.
It displays them in a block such as:
Library search paths:
/...
Parse this block to extract the implicit link directories.
While at it, remove the checks introduced by commit efaf335b (Skip
implicit link information on Xcode, 2009-07-23) and commit 5195a664
(Skip implicit link info for multiple OS X archs, 2009-09-22). Discard
the non-system link directories added by Xcode. Discard all detected
implicit libraries in the multi-architecture case but keep the
directories. The directories are still useful without the libraries
just to suppress addition of explicit -L options for them.
Drop use of cache entry CMAKE_DETERMINE_<LANG>_ABI_COMPILED and replace
it with variable CMAKE_<LANG>_ABI_COMPILED. Since the grandparent
commit this test result is specific to the version of CMake. Store it
in the version-specific compiler information files instead of
CMakeCache.txt so testing can be re-done to meet the requirements of the
current version of CMake even if another version of CMake was already
used to configure the build tree.
At the top of a build tree we configure inside the CMakeFiles directory
files such as "CMakeSystem.cmake" and "CMake<lang>Compiler.cmake" to
save information detected about the system and compilers in use. The
method of detection and the exact results store varies across CMake
versions as things improve. This leads to problems when loading files
configured by a different version of CMake. Previously we ignored such
existing files only if the major.minor part of the CMake version
component changed, and depended on the CMakeCache.txt to tell us the
last version of CMake that wrote the files. This led to problems if the
user deletes the CMakeCache.txt or we add required information to the
files in a patch-level release of CMake (still a "feature point" release
by modern CMake versioning convention).
Ensure that we always have version-consistent platform information files
by storing them in a subdirectory named with the CMake version. Every
version of CMake will do its own system and compiler identification
checks even when a build tree has already been configured by another
version of CMake. Stored results will not clobber those from other
versions of CMake which may be run again on the same tree in the future.
Loaded results will match what the system and language modules expect.
Rename the undocumented variable CMAKE_PLATFORM_ROOT_BIN to
CMAKE_PLATFORM_INFO_DIR to clarify its purpose. The new variable points
at the version-specific directory while the old variable did not.
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
Use __SIZEOF_POINTER__ which the GNU Fortran compiler defines at least
on 64-bit MinGW. Assume default size 4 on MinGW if gfortran does not
define the size.
Use the ENV{LIB} variable directly instead of parsing the output of the
whole environment from "set". Store the output in a .cmake script and
include it from CMakeDetermineCompilerABI instead of using file(READ).
To use VS C and Fotran in the same solution, it is required that VS be
able to find the Fortran run time libraries as they will be implicitly
linked by any Fortran library used by VS C programs. This adds a check
into CMakeDetermineCompilerABI using a try-compile to find the correct
PATH.
Implement support for multiarch as specified here:
http://wiki.debian.org/Multiarchhttps://wiki.ubuntu.com/MultiarchSpec
Detect the <arch> part of <prefix>/lib/<arch> from the implicit library
search path from each compiler to set CMAKE_<lang>_LIBRARY_ARCHITECTURE.
Define CMAKE_LIBRARY_ARCHITECTURE using one of these values (they should
all be the same). Teach the find_library and find_package commands to
search <prefix>/lib/<arch> whenever they would search <prefix>/lib.
The NAG Fortran compiler implicitly passes object files by full path to
the linker. Teach CMakeParseImplicitLinkInfo to parse object files that
match some tool-specific regular expression.
After configuring CMakeFiles/CMake<lang>Compiler.cmake in the build tree
the second time (to store ABI information), include it immediately.
This allows any logic and settings in the compiler information files to
be used without duplicating it in CMakeDetermineCompilerABI.cmake.
The change in commit "Use Fortran ABI detection results conservatively"
(2010-05-05) needs this to use the same logic to set CMAKE_SIZEOF_VOID_P
during first and later runs of CMake.
This commit teaches the CMAKE_PARSE_IMPLICIT_LINK_INFO function to log
its actions. We store the log in CMakeFiles/CMakeOutput.log at the top
of the project build tree. This will make diagnosis of implicit link
information parsing problems easier.
This adds copyright/license notification blocks CMake's non-find
modules. Most of the modules had no notices at all. Some had notices
referring to the BSD license already. This commit normalizes existing
notices and adds missing notices.
Implicit link information contains architecture-specific libraries and
directories. The link information cannot be explicitly specified safely
when CMAKE_OSX_ARCHITECTURES contains more than one architecture.
As a result, we currently cannot support mixed-language C++/Fortran
targets and OS X universal binaries simultaneously. In order to avoid
conflicts for simple C/C++ cases, we now simply skip detection of
implicit link information in this case.
Xcode adds extra link directories that point at the build tree, so
detection of implicit link directories is not reliable. Since Fortran
is not supported in Xcode we will not need implicit link information yet
anyway.
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.
Brad King
Rolf Eike Beer
Stephen Kelly
Kitware Robot
Bill Hoffman
Ben Boeckel
Todd Gamblin