Previously we used separate placeholders for builtin linker flags:
* CMAKE_<LANG>_LINK_FLAGS for EXECUTABLEs
* CMAKE_SHARED_LIBRARY_CREATE_<LANG>_FLAGS for SHARED libraries
* CMAKE_SHARED_MODULE_CREATE_<LANG>_FLAGS for MODULE libraries
These are now always replaced by the empty string, so drop them
from our rule variables.
With IntelLLVM on Windows, we link using the compiler driver.
With MSVC on Windows, we invoke the linker directly. If we
use both in a single build tree, for separate languages,
the value of `CMAKE_LINK_DEF_FILE_FLAG` conflicts. Add a
per-language `CMAKE_<LANG>_LINK_DEF_FILE_FLAG` variable to
avoid the conflict. Preserve the language-agnostic variable
for compatibility with projects that reference it.
Fixes: #26005
Extract the effective linker during the computation of implicit artifacts
delivered by the compiler to the linker.
Define various variables describing the linker:
* CMAKE_<LANG>_COMPILER_LINKER
* CMAKE_<LANG>_COMPILER_LINKER_VERSION
* CMAKE_<LANG>_COMPILER_LINKER_ID
* CMAKE_<LANG>_COMPILER_LINKER_FRONTEND_VARIANT
This is complementary to feature introduced by commit 96a953b1ed
(Add options to specify linker tool, 2023-09-27).
Fixes: #17596, #18209, #25344
Offer the capability, through variable `CMAKE_LINKER_TYPE`, as well as
the target property `LINKER_TYPE` to specify which linker must be used.
The implementation of this capability is specified by variables specific
to the language and linker type: `CMAKE_<LANG>_USING_LINKER_<TYPE>`.
Some definitions are provided as part of `CMake`.
For example, to select the `LLVM` linker rather than the standard one,
the type `LLD` should be specified through the variable `CMAKE_LINKER_TYPE`.
And, on `Apple`, `Linux` and some environments on `Windows`, the variable
`CMAKE_<LANG>_USING_LINKER_LLD` has value `-fuse-ld=lld`. And for `Windows`
environments based on `MSVC`, where the linker is used directly, the tool
`lld-link.exe` will be used rather than `link.exe`.
Fixes: #19174, #24254, #24990
MSYS2 and similar MinGW/MSYS distributions define development
environments with a `MSYSTEM` environment variable. Each such
environment has a documented installation prefix for its packages,
often provided by a `MSYSTEM_PREFIX` environment variable.
Since commit 84a25fc263 (cmake_host_system_information: Add
MSYSTEM_PREFIX query, 2023-09-08) we can look up this prefix.
Add `$MSYSTEM_PREFIX/local` and `$MSYSTEM_PREFIX` to our system search
prefixes when targeting MinGW under `MSYSTEM` environments. This is
their equivalent to `/usr/local` and `/usr`, which we search by default
on UNIX systems.
Issue: #24216
The fix in commit e9755bc7c1 (MinGW: Restore using windres when
toolchain-prefixed name is not available, 2022-08-15, v3.24.1~4^2)
incorrectly listed two entries in `CMAKE_RC_COMPILER_INIT`, which is
only meant to have one value. Revise the logic to support multiple
platform-specific names for the Windows Resource Compiler while still
only using one name as the fallback when it is not found.
Fixes: #24190
Issue: #23841
Since commit 55ba10dcfd (MSYS/MinGW Makefiles: Simplify selection of
windres as Resource Compiler, 2022-05-26, v3.24.0-rc1~82^2) the `MinGW
Makefiles` and `MSYS Makefiles` generators no longer specify the plain
`windres` name for the MinGW resource compiler. Instead, the name is
specified in our MinGW platform information module. After the change in
commit af4adf6aa9 (MinGW: Fix default windres selection when
cross-compiling, 2020-03-25, v3.18.0-rc1~492^2), when cross-compiling,
we only specify the toolchain-prefixed name of the tool, which may not
be available in all environments.
If the toolchain-prefixed name is not available, fall back to the plain
`windres` name. We already use this approach for other binutils.
Fixes: #23841
Extend the logic from commit 08c5b3eff0 (GNUtoMS: Add search path for VS
2019 environment scripts, 2020-01-09, v3.16.3~15^2) to consider VS 2022
paths too.
Fixes: #22847
The `MINGW` variable indicates that the compiler targets MinGW, a GNU
ABI on Windows. Since commit aff3147917 (Modernize GNU compiler info on
Windows, 2009-12-02, v2.8.2~636), we load the `Platform/Windows-GNU`
module for compilers targetin MinGW, so set the variable there instead.
This is equivalent to `Platform/Windows-MSVC` setting the `MSVC`
variable. Also remove `if(MINGW)` checks from the module, which have
not been necessary since the enclosed logic was moved to that module.
The undocumented `CMAKE_COMPILER_IS_MINGW` internal variable is now
unused, so remove it too.
Fixes: #22647
Extend the change from commit 39d0ade07e (Windows-GNU: Support duplicate
object names in large archives (#14874), 2014-04-14, v3.1.0-rc1~629^2~1)
to apply to the temporary archive we create for linking shared libraries
with MinGW tools.
Issue: #21988
Allows using different compilers with different flags for different languages.
For example Clang with GNU-like commandline for CXX and MSVC as host compiler
for CUDA.
Should help with #21914.
Since commit 957c2aac7f (RC: Simplify selection of resource compiler
based on C/C++ toolchain, 2015-05-07, v3.3.0-rc1~93^2~5) we select
windres as the RC compiler on MinGW via `CMAKE_RC_COMPILER_INIT`. Drop
the special case from commit be9afbf453 (Find mingw's windres also when
Unix Makefiles are used, 2012-08-27, v2.8.10~152^2).
Modern distributions of packages built with MinGW tools provide `.dll.a`
import libraries. Prefer those instead of finding plain `.dll` files.
This avoids accidentally finding unrelated Windows `.dll` files.
Fixes: #20019
Extend the logic from commit abe8a623d9 (GNUtoMS: Add search path for VS
2017 environment scripts, 2017-05-19, v3.8.2~1^2) to consider VS 2019
paths too.
Fixes: #20162
Use `cmake_host_system_information` to query the VS Installer tool for
the locations of VS versions since VS 2017 does not provide registry
entries anymore. Add a loop to simplify addition of future versions.
Per-source copyright/license notice headers that spell out copyright holder
names and years are hard to maintain and often out-of-date or plain wrong.
Precise contributor information is already maintained automatically by the
version control tool. Ultimately it is the receiver of a file who is
responsible for determining its licensing status, and per-source notices are
merely a convenience. Therefore it is simpler and more accurate for
each source to have a generic notice of the license name and references to
more detailed information on copyright holders and full license terms.
Our `Copyright.txt` file now contains a list of Contributors whose names
appeared source-level copyright notices. It also references version control
history for more precise information. Therefore we no longer need to spell
out the list of Contributors in each source file notice.
Replace CMake per-source copyright/license notice headers with a short
description of the license and links to `Copyright.txt` and online information
available from "https://cmake.org/licensing". The online URL also handles
cases of modules being copied out of our source into other projects, so we
can drop our notices about replacing links with full license text.
Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority
of the replacements mechanically. Manually fix up shebang lines and trailing
newlines in a few files. Manually update the notices in a few files that the
script does not handle.
Revert commit v3.3.0-rc1~435^2 (Windows-GNU: Do not tell find_library to
treat '.dll' as linkable, 2015-02-18). MinGW tools support linking to
'.dll' files directly and many non-CMake build systems still do not
provide a separate '.dll.a' file.
Update logic added in commit 957c2aac (RC: Simplify selection of
resource compiler based on C/C++ toolchain, 2015-05-07) to avoid
overriding CMAKE_GENERATOR_RC. The MinGW and MSYS Makefiles
generators use it to select a windres next to the compiler even
if it is not in the PATH.
Revert the refactoring by commit v2.8.11~105^2~1 (Ninja: use MinGW
generator code in EnableLanguage, 2013-03-09) and move the MinGW-
specific logic back to the "MinGW Makefiles" generator. Instead teach
the platform information modules for GNU and MSVC on Windows to set the
preferred RC compiler just before enabling the RC language. This way
we choose the RC compiler based on the C/C++ toolchain that is actually
enabled.
The RC language is special in that it is automatically enabled
on Windows-based platforms when another primary language is
enabled. Move enablement of RC from early in the enablement
of the other language to late. This will allow it to use
information detected as part of enabling C, CXX, or Fortran.
Add to the Platform/Windows-GNU module list of VS registry entries those
for VS 2013. Also add the name "vcvars64.bat" used by VS 10 and above
for 64-bit tools.
Since commit v2.6.0~388 (Added build rule variables
CMAKE_<LANG>_ARCHIVE_..., 2008-01-29) we use separate "ar cr ..." and
"ar r ..." steps to incrementally add a large list of object files to an
archive. Since the "r" command replaces existing objects of the same
name in an archive, if multiple objects have the same file name and
appear in separate append steps then one overwrites the other. Instead,
use "ar cq ..." and "ar q ..." to always append to the archive.
We already remove the archive before creating it so this will not cause
objects to be appended to existing archives on incremental rebuilds.
Work around the command-line-length limit by using an @linklibs.rsp
response file to pass the flags for link libraries. This allows
very long lists of libraries to be used in addition to the existing
support for passing object files via response file.
Suggested-by: Peter Keuschnigg <peter.keuschnigg@pmu.ac.at>
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"'\(\s*\)(.\+)/'"$c"'\1()/'
done >convert.sed &&
git ls-files -z -- bootstrap '*.cmake' '*.cmake.in' '*CMakeLists.txt' |
egrep -z -v '^(Utilities/cm|Source/kwsys/)' |
egrep -z -v 'Tests/CMakeTests/While-Endwhile-' |
xargs -0 sed -i -f convert.sed &&
rm convert.sed
The work around is only needed by older GCCs (only testet 4.4/4.7)
Ninja is very new so chances are high that there is also a new mingw.
Use slashes in link rsp file, because ar.exe can't handle \.
Store in new platform variables
CMAKE_${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.
