Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Cmake speedups #1905

Merged
merged 3 commits into from
Feb 18, 2022
Merged

Cmake speedups #1905

merged 3 commits into from
Feb 18, 2022

Commits on Feb 17, 2022

  1. Always skip update command for git based external projects 

    I noticed that some external projects were being reconfigured/built
with every make, even though no files in the external project had been
updated.

With some debugging I noticed that git based external projects were
re-running their "update" step every time, and that in turn caused the
configure/build/install steps to re-run as well. (Generally the build
step is a no-op as the Makefile/etc. in the external project is well
formed and doesn't do anything, but the configure/install steps still
run).

It seems related to this cmake bug:
https://gitlab.kitware.com/cmake/cmake/-/issues/19703. In short, the
git update step for an external project does not create any "done"
file that denotes that the files are still up-to-date. Without that
"done" file, the update step is always run, and that in turn causes
the other steps for the external project to re-run as well.

The best way to fix this seems to be to skip the update step by
defining an empty UPDATE_COMMAND. As long as the downloaded code for a
given hash/tag/etc does not change, the update step is unnecessary.

And if we *really* wanted to ensure unchanged dependencies, we would
download our own copies anyway.

Making this change significantly cleans up the falco build to avoid
rebuilding git based external dependencies.

Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
    @mstemm
    mstemm committed Feb 17, 2022
    Configuration menu
    Copy the full SHA
    11d2029 View commit details
    Browse the repository at this point in the history

  2. Cmake function to copy files from source to build dir, as a target 

    Define a cmake function copy_files_to_build_dir(source_files,
targetsuffix) that defines a single custom target and single custom
command to copy the set of source files to
CMAKE_CURRENT_BINARY_DIR. All of the real work is done via cmake -E
copy_if_different.

This function will replace the nearly identical cmake code in several
other directories. This function has the advantage of being a single
target for the set of source files instead of a target per-file.

Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
    @mstemm
    mstemm committed Feb 17, 2022
    Configuration menu
    Copy the full SHA
    a1443ef View commit details
    Browse the repository at this point in the history

  3. Use cmake function to copy files, as a single target 

    Replace nearly-identical blocks of code that defined individual custom
targets/custom commands to copy files from source to build dir with
the copy_files_to_build_dir function.

This reduces the number of build targets and speeds up/cleans up the
make output.

Signed-off-by: Mark Stemm <mark.stemm@gmail.com>
    @mstemm
    mstemm committed Feb 17, 2022
    Configuration menu
    Copy the full SHA
    517ff1b View commit details
    Browse the repository at this point in the history