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.
Changes in commit b9aa5041 (cmLocalGenerator: Simplify GetIncludeFlags
output formatting, 2014-03-04) caused Windows Resource Compiler include
directories to be computed as relative paths in the Ninja generator.
This breaks the cmcldeps handling of include paths. The reason for the
regression is that several cmLocalGenerator::GetIncludeFlags callers
treated the fourth "bool forResponseFile" argument as if it controlled
whether include directories were a full path. It actually did control
that by accident until the above commit.
Add an explicit "bool forceFullPaths" argument to GetIncludeFlags
and thread the value through ConvertToIncludeReference as needed.
Update GetIncludeFlags call sites that really wanted to control the
forResponseFile setting to be aware of the new argument. Extend the
VSResource test to cover this case.
The pre-defined 'console' pool is a non-buffered pool that runs with a
depth of 1. CMake re-run cannot be run concurrently and it will
eventually output something. A non-buffered pool allows to get it as
soon as possible
Also, generate the minimal required version of Ninja in the build file.
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.
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.
As an INTERFACE_LIBRARY has no direct link dependencies, we can
short-circuit in cmGeneratorExpressionEvaluator and
in cmGlobalGenerator::CheckLocalGenerators.
As they do not generate any output directly, any generate- or install-
related code acn also be short-circuited. Many of the local generators
already do this.
Because only INTERFACE related properties make sense on INTERFACE_LIBRARY
targets, avoid setting other properties, for example via defaults.
Just enough to reach the BuildMacContentDirectory method and the
NeedRelinkBeforeInstall methods.
In the future, those methods can be moved to cmGeneratorTarget.
Drop the "vsProjectFile" argument from cmTarget::TraceDependencies. It
appears to be the modern equivalent to a hunk added in commit ba68f771
(...added new custom command support, 2003-06-03):
+ name = libName;
+ name += ".dsp.cmake";
+ srcFilesToProcess.push(name);
but was broken by refactoring at some point. The current behavior tries
to trace dependencies on a source file named the same as a target, which
makes no sense. Furthermore, in code of the form
add_executable(foo foo.c)
add_custom_command(OUTPUT "${somewhere}/foo" ... DEPENDS foo)
the "vsProjectFile" value "foo" matches source "${somewhere}/foo.rule"
generated to hold the custom command and causes the command to be added
to the "foo" target incorrectly.
Simply drop the incorrect source file trace and supporting logic.
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
eb410e8 Ninja: disable cldeps for bcc32, it's too old, and ninja would also not build
5ead31d Ninja: try work around for bcc32 bug
1333b57 Ninja: build server fixes
9081e3a remove warning about unused parameter
f430bea Ninja: maybe this fixes the bcc32 build
f2c1288 Ninja: msvc6 for-scoping
44b9bbc Ninja: build with old msvc versions
57156a5 Ninja: build server fixes
f1abdce Ninja: some bytes of the rc files couldn't be piped correctly
2de963d Ninja: don't remove space between command and parameters
50b6f33 Ninja: build cmcldeps with mingw
c05653e Ninja: try to make GetProcessId visible
ab245ff Ninja: but cl supports /nologo ...
bf58e9a Ninja: no /nologo option in old rc.exe
2fb07fc Ninja: Eclipse and KDevelop fixes for ninja
518c065 Ninja: don't pollute build dir with preprocessed rc files
...
When linking with cmake and vs_link_* the command line
could be too long for cmd.exe, which needs not to be
called in this case. (was not cached by a test)
Introduce rules which don't use the shell and use this
rule when there are no pre or post step.
For free we get a small speedup, because cmd is then
not called.
Also be more accurate when estimating the
command line length.
Older C++ compilers do not provide a standard std::stringstream.
Use our compatibility interfaces instead.
Also avoid std::stringstream(openmode) signature. Our approximate
stringstream implementation provided when the standard one is not
available does not support the openmode argument.
When MinGW is used slashes are used for dependencies
because ar.exe can't read rsp files with backslashes.
Many thx to Claus Klein for starting working on this.
Implement cmGlobalGenerator::ComputeTargetObjects in the Ninja generator
to pre-compute all the object file names. Use the results during
generation instead of re-computing it later.
Generally these are only required in build statements, as Ninja wants
to be able to chop paths up. But it doesn't hurt to also try to use
them in command line arguments.
Brad King
Stephen Kelly
Peter Collingbourne
Nils Gladitz
Sylvain Joubert
Ben Boeckel
Peter Kümmel
Robert Maynard
Ian Monroe
David Cole