Since commit 777ceaea94 (cmMakefile: Delay custom command creation,
2019-10-17, v3.17.0-rc1~352^2) we process custom command declarations at
generate time. Therefore we do not need to look up what source file
holds the custom command producing a given output until generate time.
For NVCC the compiler takes care of device linking when passed the "-dlink"
flag.
Clang doesn't support such magic and requires the buildsystem to do the work
that NVCC does behind the scenes.
The implementation is based on Bazel's device linking documentation:
7cabcdf073/third_party/nccl/build_defs.bzl.tpl (L259)Closes: #20726
#pragma once is a widely supported compiler pragma, even though it is
not part of the C++ standard. Many of the issues keeping #pragma once
from being standardized (distributed filesystems, build farms, hard
links, etc.) do not apply to CMake - it is easy to build CMake on a
single machine. CMake also does not install any header files which can
be consumed by other projects (though cmCPluginAPI.h has been
deliberately omitted from this conversion in case anyone is still using
it.) Finally, #pragma once has been required to build CMake since at
least August 2017 (7f29bbe6 enabled server mode unconditionally, which
had been using #pragma once since September 2016 (b13d3e0d)). The fact
that we now require C++11 filters out old compilers, and it is unlikely
that there is a compiler which supports C++11 but does not support
#pragma once.
Since commit a9b41195d2 (Handle multi-arch sysroots on Apple platforms,
2019-07-26, v3.17.0-rc1~287^2), CMake supports "fat" builds with
different sysroots. Those are passed to the compiler with the
`-Xarch_<xyz>` parameter.
Unfortunately this breaks the Compiler Cache (ccache) because
it does not support those compiler flags:
https://github.com/ccache/ccache/blob/v3.7.9/src/ccache.c#L2700-L2705
Restore the caching ability for certain "fat" build configurations (e.g.
`arm64` and `armv7`) where the sysroot is the same for all selected
architectures and thus a plain `-isysroot` parameter could be used.
properties LINK_OPTIONS and INTERFACE_LINK_OPTIONS are propagated
to the device link step.
To control which options are selected for normal link and device link steps,
the $<DEVICE_LINK> and $<HOST_LINK> generator expressions can be used.
Fixes: #18265
Adds a flag to indicate that pipe output from a custom command should be
interpreted as UTF-8 encoded. This change does not introduce a public
way to set the flag, but generators that create internally-generated
commands know if they are calling cmake, which uses UTF-8 pipes.
MSBuild added support for interpreting output of PreBuildEvent,
PreLinkEvent, PostBuildEvent, and CustomBuildStep as UTF-8. This change
will appear in Visual Studio 16.6 Preview 3. It is opt-in, and you need
to add the StdOutEncoding tag. MSBuild treats these as property bags so
if we emit the tag for earlier versions of Visual Studio it would be
safely ignored. This change emits the StdOutEncoding tag and sets it to
UTF-8 whenever the custom command UTF-8 pipe flag is set. This fixes
globalization issues when the output from cmake contained characters
that required MSBuild to interpret as UTF-8 before displaying them.
The `CMAKE_OSX_ARCHITECTURES` value is not used directly by generators.
It is used to initialize a per-target `OSX_ARCHITECTURES` property, but
that property can also be set explicitly by project code to a subset of
the full list of architectures. In order to handle this case, construct
a mapping from each `CMAKE_OSX_ARCHITECTURES` entry to the corresponding
`CMAKE_APPLE_ARCH_SYSROOTS` entry by name. Use the mapping to find the
sysroot for each entry in `OSX_ARCHITECTURES` for a given target.
If `CMAKE_APPLE_ARCH_SYSROOTS` does not have the same length as
`CMAKE_OSX_ARCHITECTURES`, error out early rather than risking a crash
or assertion failure.
Fixes: #20534
Move custom command creation to cmLocalGenerator and dispatch custom
commands in cmMakefile to generate time. Generators add custom commands
using the new methods provided by cmLocalGenerator.
Issue: #12877
Since commit b80557c7bd (file(GENERATE): Evaluate early to allow
generating source files, 2014-11-04, v3.2.0-rc1~398^2) we create the
`cmSourceFile` instances marked with a `GENERATED` source file property
before tracing source dependencies. Move it to even earlier so that
steps in `cmGlobalGenerator::AddAutomaticSources` can operate on all
sources. This also avoids the accidental `O(n^2)` calls for `n` local
generators that we had previously.
This is also needed since commit 83c1657ff7 (Unity build: Generate
sources during Compute step, 2019-10-03) to support `file(GENERATE)`
outputs as sources in a target with `UNITY_BUILD` enabled.
The unity build sources need to be added for all generators. Create
them during `cmGlobalGenerator::Compute` to avoid duplicating the calls
in every generator. We already handle Qt autogen there too.
Issue: #19789
Entries of the `CPATH` environment variable are implicitly searched as
include directories by some C/C++ compilers. Since commit 5990ecb741
(Compute implicit include directories from compiler output, 2018-12-07,
v3.14.0-rc1~108^2) these entries are detected by CMake and included in
the `CMAKE_{C,CXX}_IMPLICIT_INCLUDE_DIRECTORIES` variables.
However, we should not exclude them from explicit specification via `-I`
or particularly `-isystem` because they are meant as user-specified
include directories that can be re-ordered without breaking compiler
builtin headers. In particular, we need explicit requests via
`include_directories` with the `SYSTEM` option to result in `-isystem`
so that third-party headers do not produce warnings.
Co-Author: Ben Boeckel <ben.boeckel@kitware.com>
Fixes: #19291
This patch strips the `stripImplicitDirs` and `appendAllImplicitDirs`
parameters from the `cmLocalGenerator::GetIncludeDirectories` method and makes
it a wrapper into the new `cmLocalGenerator::GetIncludeDirectoriesImplicit`
method. `cmLocalGenerator::GetIncludeDirectoriesImplicit` is the renamed old
implementation of `cmLocalGenerator::GetIncludeDirectories` and still
accepts `stripImplicitDirs` and `appendAllImplicitDirs`.
The motivation is that there's only *one* case where
`cmLocalGenerator::GetIncludeDirectories` is called with the
`stripImplicitDirs` parameter being `false` (QtAutoGen), but many other places
where it is called using the `true` default value.
QtAutoGen is modified to use `cmLocalGenerator::GetIncludeDirectoriesImplicit`
directly. In two use cases of `cmLocalGenerator::GetIncludeDirectories`
the manually set `true` value for `stripImplicitDirs` is removed.
