Provide a way for custom commands to inform the ninja build tool about
their implicit dependencies. For now simply make use of the option an
error on other generators.
Closes: #15479
With the Makefile generator one can use `cd $subdir; make install` to build and
install targets associated with a given subdirectory. This is not possible to
do with the Ninja generator since there is only one `build.ninja` file at the
top of the build tree. However, we can approximate it by allowing one to run
`ninja $subdir/install` at the top of the tree to build the targets in the
corresponding subdirectory and install them.
This also makes sense for `test`, `package`, and other GLOBAL_TARGET targets.
It was already done for `all` by commit v3.6.0-rc1~240^2~2 (Ninja: Add
`$subdir/all` targets, 2016-03-11).
Run the `Utilities/Scripts/clang-format.bash` script to update
all our C++ code to a new style defined by `.clang-format`.
Use `clang-format` version 3.8.
* If you reached this commit for a line in `git blame`, re-run the blame
operation starting at the parent of this commit to see older history
for the content.
* See the parent commit for instructions to rebase a change across this
style transition commit.
Sort include directives within each block (separated by a blank line) in
lexicographic order (except to prioritize `sys/types.h` first). First
run `clang-format` with the config file:
---
SortIncludes: false
...
Commit the result temporarily. Then run `clang-format` again with:
---
SortIncludes: true
IncludeCategories:
- Regex: 'sys/types.h'
Priority: -1
...
Commit the result temporarily. Start a new branch and cherry-pick the
second commit. Manually resolve conflicts to preserve indentation of
re-ordered includes. This cleans up the include ordering without
changing any other style.
Use the following command to run `clang-format`:
$ git ls-files -z -- \
'*.c' '*.cc' '*.cpp' '*.cxx' '*.h' '*.hh' '*.hpp' '*.hxx' |
egrep -z -v '(Lexer|Parser|ParserHelper)\.' |
egrep -z -v '^Source/cm_sha2' |
egrep -z -v '^Source/(kwsys|CursesDialog/form)/' |
egrep -z -v '^Utilities/(KW|cm).*/' |
egrep -z -v '^Tests/Module/GenerateExportHeader' |
egrep -z -v '^Tests/RunCMake/CommandLine/cmake_depends/test_UTF-16LE.h' |
xargs -0 clang-format -i
This selects source files that do not come from a third-party.
Inspired-by: Daniel Pfeifer <daniel@pfeifer-mail.de>
A common idiom in CMake-based build systems is to have custom commands
that generate files not listed explicitly as outputs so that these
files do not have to be newer than the inputs. The file modification
times of such "byproducts" are updated only when their content changes.
Then other build rules can depend on the byproducts explicitly so that
their dependents rebuild when the content of the original byproducts
really does change.
This "undeclared byproduct" approach is necessary for Makefile, VS, and
Xcode build tools because if a byproduct were listed as an output of a
rule then the rule would always rerun when the input is newer than the
byproduct but the byproduct may never be updated.
Ninja solves this problem by offering a 'restat' feature to check
whether an output was really modified after running a rule and tracking
the fact that it is up to date separately from its timestamp. However,
Ninja also stats all dependencies up front and will only restat files
that are listed as outputs of rules with the 'restat' option enabled.
Therefore an undeclared byproduct that does not exist at the start of
the build will be considered missing and the build will fail even if
other dependencies would cause the byproduct to be available before its
dependents build.
CMake works around this limitation by adding 'phony' build rules for
custom command dependencies in the build tree that do not have any
explicit specification of what produces them. This is not optimal
because it prevents Ninja from reporting an error when an input to a
rule really is missing. A better approach is to allow projects to
explicitly specify the byproducts of their custom commands so that no
phony rules are needed for them. In order to work with the non-Ninja
generators, the byproducts must be known separately from the outputs.
Add a new "BYPRODUCTS" option to the add_custom_command and
add_custom_target commands to specify byproducts explicitly. Teach the
Ninja generator to specify byproducts as outputs of the custom commands.
In the case of POST_BUILD, PRE_LINK, and PRE_BUILD events on targets
that link, the byproducts must be specified as outputs of the link rule
that runs the commands. Activate 'restat' for such rules so that Ninja
knows it needs to check the byproducts, but not for link rules that have
no byproducts.
Disallow the use of config-specific source files with
the Visual Studio and Xcode generators. They don't have
any way to represent the condition currently.
Use the same common-config API in cmQtAutoGenerators. While
it accepts config-specific files, it doesn't have to support
multiple configurations yet.
Loop over the configs in cmTargetTraceDependencies
and cmGlobalGenerator::WriteSummary and consume all source
files.
Loop over the configs in cmComputeTargetDepends and compute the
object library dependencies for each config.
Until now the cmCustomCommandGenerator was used only to compute the
command lines of a custom command. Generalize it to get the comment,
working directory, dependencies, and outputs of custom commands. Update
use in all generators to support this.
Just enough to reach the BuildMacContentDirectory method and the
NeedRelinkBeforeInstall methods.
In the future, those methods can be moved to cmGeneratorTarget.
To properly track the usage of dependencies that are generated at
compile time as the side effect of other build steps we need
to make the WriteBuild and WritePhonyBuild commands non static
Kulla Christoph
Daniel Pfeifer
Brad King
Nicolas Despres
Kitware Robot
Stephen Kelly
Peter Collingbourne
Robert Maynard