638f00117a Add release note for the -S and -B options.
de962cc00d CMake: Internally uses -S instead of -H to specify source directory
a10d63d578 cmake: -S and -B can be used to specify source and build directories
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2358
After changing the ``cmGeneratedFileStream`` methods to accept
``std::string const&`` instead of ``const char*`` we don't
need to call ``std::string::c_str`` anymore when passing
a ``std::string`` to a ``cmGeneratedFileStream`` method.
This patch removes all redundant ``std::string::c_str``
calls when passing a string to a ``cmGeneratedFileStream`` method.
It was generated by building CMake with clang-tidy enabled using
the following options:
-DCMAKE_CXX_CLANG_TIDY=/usr/bin/clang-tidy-4.0;-checks=-*,readability-redundant-string-cstr;-fix;-fix-errors
Run the `clang-format.bash` script to update all our C and C++ code to a
new style defined by `.clang-format`. Use `clang-format` version 6.0.
* 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.
While we already support `cmake --build . -- -j`, the options after `--`
are specific to the native build tool. Add new options `--parallel
[<N>]` and `-j [<N>]` to abstract this and map to the proper option
for the native build tool.
Since its beginning the Ninja generator has handled `GENERATED` source
files that have no custom command producing them by writing a dummy
custom command for them that depends on the target ordering phony edge.
Make the custom command's dependency order-only since the phony edge
also has only order-only dependencies. The dummy custom command
should never be considered "dirty" by `ninja`.
Fixes: #17942
When tracking module names internally, include the `.mod` extension.
This will later be useful to distinguish them from `.smod` extensions
for submodules.
* Change some functions to take `std::string` instead of
`const char*` in the following classes: `cmMakeFile`, `cmake`,
`cmCoreTryCompile`, `cmSystemTools`, `cmState`, `cmLocalGenerator`
and a few others.
* Greatly reduce using of `const char*` overloads for
`cmSystemTools::MakeDirectory` and `cmSystemTools::RelativePath`.
* Remove many redundant `c_str()` conversions throughout the code.
Calls to this method may dominate generation time in some cases.
Measurements for configuring cmake itself show a cache hit rate of ~57%
(7753 total calls, 4453 cache hits). For a larger project (that also
makes use of custom targets as prerequisite for all compile targets),
the measured cache hit ratio is ~96% (2530827 total calls, 2433124 cache
hits). For this project the observable cmake runtime could be reduced
from 40s to 30s.
Signed-off-by: Matthias Maennich <matthias@maennich.net>
The commit v3.7.0-rc1~339^2 (Ninja: Fix inter-target order-only
dependencies of custom command, 2016-07-20) might cause performance
degradations for larger projects. Especially when using custom
commands as an input for each compilation rule (e.g. generated headers).
For reference in the following I am referring to
Source/cmGlobalNinjaGenerator.cxx:
-> cmGlobalNinjaGenerator::AppendTargetDependsClosure
-> cmGlobalNinjaGenerator::ComputeTargetDependsClosure
It turned out that the mentioned commit is doing (indirectly) some
redundant work that might impact performance when generating large
projects.
Imagine the dependency tree of custom targets:
A
\
C - D - E
/
B
For each target the transitive closure is calculated recursively, but as
the TargetDependsClosures are only cached on the top most level, everything
downstream has to be recalculated. I.e.
A->C->D->E
B->C->D->E
This ultimately leads to a lot of redundant calls to AppendTargetOutputs.
The recursive nature of the algorithm itself is not significant to the
problem, but reducing the work to actually to be done work, eliminates the
performance problem.
This patch changes the way, intermediate results are cached. Rather than
caching the closure of targets, we cache the closure of outputs. Such that
in the example above at B->C the cache already would kick in.
Caching the outputs has one disadvantage that the patch takes care of.
In case of such a structure
A E
\ / \
C - D G
/ \ /
B F
the calling order for A would be
A->C->D->E->G (at which time G is seen to the recursion)
then the recursion returns until it reaches
A->C->D->F (at which the seen G would prevent to recurse down to G)
But this would poison the cache for F with a wrong value (without G).
Hence we use a local result set to ensure the cache is still consistently
populated.
For a large C++ project with around 25k targets this reduced the CMake
configure / generate time from ~40s to ~29s.
Signed-off-by: Matthias Maennich <matthias@maennich.net>
For CMP0058 we identify dependencies that have no rules to generate them
by collecting a set of all dependencies and a set of all files CMake
knows are generated by something, and then computing a set difference.
Fix construction of these sets to use the same form for each path.
This is after ConvertToNinjaPath but before EncodePath.
Without this, the slash conversion done by EncodePath for the GNU
compiler on Windows results in a mismatch, triggering an incorrect
CMP0058 warning.
This fixes a false-positive `CMP0058` warning if any custom rules depend
on `compile_commands.json` (e.g. to trigger rerunning clang-tooling
utilities).
Fixes: #16444
The internal tool "cmake_ninja_depends" now supports reading the list of ddi
files from a reponse file to circumvent Windows command line length limits.
Use this response file for dyndep rule on Windows.
Previously, given two libraries, X and Y where X depends on Y, all
object compilations of X would require the Y library to have been linked
before being compiled. This is not necessary and can instead be loosened
such that object compilations of X only depend on the order-only
dependencies of Y to be completed. This is to ensure that generated
sources, headers, custom commands, etc. are completed before X starts to
compile its objects.
This should help build performance in projects with many libraries which
cause a deep library dependency chain. Previously, a library at the
bottom would not start compilation until after all other libraries
completed, but now only its link step needs to wait and its compilation
jobs can be run in parallel with other tasks.
Fixes: #15555
Move the logic to cmSystemTools to be shared among the generators.
Revise the implementation and add comments justifying each possible
source for a limit.
The targets added by commit v3.6.0-rc1~240^2~2 (Ninja: Add `$subdir/all`
targets, 2016-03-11) use as `$subdir` the relative path from the top of
the source tree to the current source directory. This is not correct
when using `add_subdirectory(test test_bin)`. Instead we need to use
the relative path from the top of the binary tree to the current binary
directory as was done for related targets by commit v3.7.0-rc1~268^2
(Ninja: Add `$subdir/{test,install,package}` targets, 2016-08-05).
