Since commit v2.8.8~176^2 (try_compile: Use random executable file name,
2012-02-13) the length of the test executable name in generated
try_compile projects has been longer and unpredictable. With Visual
Studio on windows, the tools try to create paths like:
CMakeFiles/CMakeTmp/$tgt.dir/Debug/$tgt.tlog/$tgt.lastbuildstate
With the target name repeated up to 3 times, we must make it short and
of consistent length to avoid overrunning the 260 character limit
imposed by VS tools.
d0adcccb try_run: Add tests for LINK_LIBRARIES with mock libraries.
223c5cb7 try_run: Add test for bad link libraries.
e2b1f058 try_run: Add support for LINK_LIBRARIES option.
Most functionality is already implemented in Source/cmCoreTryCompile.{h,cxx}.
Document and improve argument parsing.
This functionality is already being used by a number of modules, like
CheckCSourceCompiles.cmake, but it is not documented.
Copy CMAKE_EXE_LINKER_FLAGS into the test project generated by
try_compile, just like we already copy CMAKE_<LANG>_FLAGS.
Add CMake Policy CMP0056 to activate this behavior in a compatible way,
but do not warn by default when the policy is not set since it will
affect all try_compile calls.
Extend the RunCMake.try_compile test with a case covering this behavior
for each policy setting.
When compiling the ABI detection test project, do not override
CMAKE_EXE_LINKER_FLAGS completely. The normally selected value of this
variable may influence how the link is done and may be needed to be
representative of how the calling project will be built. Instead pass a
variable that try_compile will reference as additional flags. Leave
this behavior of try_compile undocumented for now.
No call sites pass NULL to the output argument, so take it by
reference to avoid the if(output) conditions. Propagate the
change through the TryCompile APIs that call it.
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.
Several CMake operations need to replace files in rapid succession.
This commonly fails on Windows due to filesystem lock behavior so
we have retry loops. No matter how many times we retry or how long
we delay there will inevitably be someone with an environment that
needs more. Make the retry count and delay configurable in the
Windows Registry keys:
{HKCU,HKLM}/Software/Kitware/CMake/Config
in DWORD values
FilesystemRetryCount = Number of tries
FilesystemRetryDelay = Delay in milliseconds between tries
Leave the feature undocumented for now to see how it goes.
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.
As CMAKE_ROOT_FIND_PATH can be a list, a new CMAKE_SYSROOT is
introduced, which is never a list.
The contents of this variable is passed to supporting compilers
as --sysroot. It is also accounted for when processing implicit
link directories reported by the compiler, and when generating
RPATH information.
Clang can compile code, but uses the gcc tools for other tasks such
as linking. The -gcc-toolchain option can be used for that, but
generalize so that other compilers can be treated the same.
If such a location is specified, use it as a hint for finding
the binutils executables.
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 ${arch})
Both clang and qcc are inherently cross compiler( driver)s.
When cross-compiling with clang, use the CMAKE_${lang}_COMPILER_TARGET
as the _CMAKE_TOOLCHAIN_PREFIX to find the appropriate binutils.
When cross-compiling with QNX qcc, use the CMAKE_${lang}_COMPILER_TARGET
to set the appropriate _CMAKE_TOOLCHAIN_PREFIX.
This has follow-on effects for other methods and classes. Further
work on making the use of const cmTarget pointers common can be
done, particularly with a view to generate-time methods.
The commits 9db31162 (Remove CMake-language block-end command
arguments, 2012-08-13) and 77543bde (Convert CMake-language
commands to lower case, 2012-08-13) changed most cmake code
to use lowercase commands and no parameters in termination
commands. However, those changes excluded cmake code generated
in c++ by cmake.
Make a similar style change to code generated by cmake.
When the COPY_FILE operation fails optionally capture the error message
with a COPY_FILE_ERROR option instead of reporting the error
immediately. This gives callers a chance to do something else or report
the error.
Teach the RunCMake.try_compile test to cover bad argument combinations
involving COPY_FILE_ERROR. Teach the TryCompile test to cover the case
of a COPY_FILE error message captured by COPY_FILE_ERROR.
If CMAKE_<lang>_FLAGS contains quotes or other CMake language characters
they must be escaped when written into the generated CMakeLists.txt file
so that the test project parses them properly.
Teach the TryCompile test to cover this case by adding a flag with
quotes into CMAKE_C_FLAGS during a C language try_compile.
AddCMakeDependFile and AddCMakeOutputFile both store as std::string
and all calling sites use std::string. So instead of creating more
temporary objects, lets just use std::strings.
Extend the signature
try_compile(RESULT_VAR <bindir> <srcfile> ...)
to allow multiple sources as
try_compile(RESULT_VAR <bindir> SOURCES <srcfile>... ...)
Process the sources to generate a CMakeLists.txt that enables all needed
languages.
Teach the TryCompile test to try cases with two sources of the same
language and of mixed languages. Teach RunCMake.try_compile to cover
error cases for the signature.
Process all arguments in a single loop using a simple state machine.
While at it, fix some error message typos. Also allow LINK_LIBRARIES
with no actual libraries to disable use of the -DLINK_LIBRARIES=...
from the CMAKE_FLAGS. This was already possible in the old logic if
LINK_LIBRARIES was immediately followed by another keyword argument
instead of the end of the argument list, so allow it in general.
Update the RunCMake.try_compile test cases accordingly.
Commit e65ef08b (try_compile: Fix quoting of libraries in generated
CMakeLists.txt, 2013-05-24) added quoting to entries specified in
the LINK_LIBRARIES. However, if the input entries contain whitespace
padding, that quoted whitespace causes an error in the generated
CMakeLists.txt at target_link_libraries.
Strictly, it is an error to have space separated entries in the
CMAKE_REQUIRED_LIBRARIES, as it was never properly handled by
CMakeExpandImportedTargets even prior to commit 236133e7 (Handle
targets in the LINK_LIBRARIES of try_compile., 2013-02-09). However,
it is causing a regression in KDE code which tests the next branch.
Since commit 236133e7 (Handle targets in the LINK_LIBRARIES of
try_compile, 2013-02-09) libraries passed to the new LINK_LIBRARIES
option of try_compile are not quoted inside the generated CMakeLists.txt
file. Quote the library names so they re-parse correctly when loaded by
CMake to configure and generate the test project.
Reported-by: Bogdan Cristea <cristeab@gmail.com>
In commit 236133e7 (Handle targets in the LINK_LIBRARIES of try_compile,
2013-02-09) an error return case was added without closing the file in
progress. Add the missing fclose() call.
Spotted by sevenhill.
Imported targets are re-exported so that they can be used by the
try_compile generated code with target_link_libraries.
This makes the use of the cmake_expand_imported_targets macro
obsolete. The macro is not able to expand the generator expressions
which may appear in the IMPORTED_LINK_INTERFACE_LIBRARIES content.
Instead it just sees them as 'not a target'.
CMAKE_SHARED_LIBRARY_<lang>_FLAGS has flags on various platforms for a
variety of purposes that are correlated with shared libraries but not
exclusive to them. Refactor generation of these flags to use new
purpose-specific platform variables
CMAKE_<lang>_COMPILE_OPTIONS_DLL
CMAKE_<lang>_COMPILE_OPTIONS_PIC
CMAKE_<lang>_COMPILE_OPTIONS_PIE
Activate the DLL flags specifically for shared libraries. Add a new
POSITION_INDEPENDENT_CODE target property to activate PIC/PIE flags, and
default to true for shared libraries to preserve default behavior.
Initialize the new property from CMAKE_POSITION_INDEPENDENT_CODE to
allow easy global configuration in projects.
Although the default behavior is unchanged by this refactoring, the new
approach ignores CMAKE_SHARED_LIBRARY_<lang>_FLAGS completely. We must
leave it set in case projects reference the value. Furthermore, if a
project modifies CMAKE_SHARED_LIBRARY_<lang>_FLAGS it expects the new
value to be used. Add policy CMP0018 to handle compatibility with
projects that modify this platform variable.
Add a PositionIndependentCode test on platforms where we can get
meaningful results.
Since commit 4fbdce2b (try_compile: Use random executable file name,
2012-02-13) a different <target>.dir is used for each try-compile.
Cleanup the directories as well as their content to avoid accumulating
leftover temporary directories.
Stephen Kelly
Brad King
Nils Gladitz
Matt McCormick
Bill Hoffman
Ben Boeckel
Rolf Eike Beer
Clinton Stimpson
Robert Maynard
Rolf Eike Beer