TL;DR: Save 10 minutes of CI time for GHA/macos jobs using pre-fills and
add pre-fill verification for Apple and Windows. Also restores Xcode job
and saves 1.5-10 minutes configuring iOS jobs.
Pre-filling feature detection results can bring down the CMake configure
step to ~5 seconds on most GHA runners, ~10 seconds in slow envs like
Cygwin/MSYS2.
The potential savings per job are:
- 5-40 (average 19) seconds on GHA/macos (33 jobs)
- ~10 seconds on GHA for iOS GNU Makefile (1 job)
- 1.5-10 minutes on GHA for iOS Xcode generator (1 job)
- 10 seconds on GHA/linux with native Ubuntu (12 jobs)
- 40 seconds for Cygwin/MSYS2 (2 jobs)
- 5-10 seconds for virtualized BSDs, native CPU (3 jobs)
- ~60 seconds for virtualized BSDs, emulated CPU (1 job)
On native Windows pre-filling has been in place for a long time and
saving 8 minutes (VS2019-VS2015) to 1.5-2 minutes (VS2022), 3 minutes
(VS2022 UWP), and 30-60 seconds (MinGW), per CI job.
The downside is that detection results need to be manually collected and
filtered to those that universally apply to all platforms that they are
enabled on. Another downside is that by using a cache, we're not running
the actual detections, and thus won't catch regressions in them. It
means we must make sure that the cache is solid and matches with actual
detections results. An upside is that it gives a rough overview of which
features are available on which platforms. Another upside is pre-filled
values do work for feature detections skipped for cross-builds, e.g.
`HAVE_WRITABLE_ARGV`.
This PR adds a pre-fill cache that supports all Unixes (except OmniOS)
used in CI, and makes it usable with an internal option. It also enables
it for GHA/macos CI jobs, where the maximum savings are. And also for
the two iOS [1] and two Cygwin/MSYS2 jobs. The latters don't have
pre-fill checks and we can drop them if they turn into a hassle.
Saving:
- 10 minutes of CI time per GHA/macos workflow run. [2]
- ~80 seconds per GHA/windows workflow run with Cygwin/MSYS2.
(offsetting the cost of pre-fill verifications)
- 1.5-10 minutes per GHA/non-native runs with iOS jobs. [3]
You can enable pre-fill locally with `-D_CURL_PREFILL=ON`. It's
experimental, and if you experience a problem, file a PR or an Issue.
This PR also adds a pre-fill checker for macOS and MinGW/MSVC Windows
GHA jobs to catch if the cache diverges from real detections. It also
adds this logic to AppVeyor, but doesn't enable it due to the perf
penalty of 2 minutes mininum.
The pre-fill checker works by configuring out-of-tree with and without
pre-fill, then diffing their `lib/curl_config.h` outputs.
Exceptions are 3 detection results exposed indirectly [4], and missing
to expose 2, of which one is the C89 header `stddef.h`. While we assume
the C99 `stdint.h` available outside iOS. We can expose them in the
future, if necessary.
The pre-fill checks cost in total:
- ~20 seconds for macOS
- ~40 seconds for MinGW on GHA
- ~80 seconds for MSVC on GHA (UWP would be 2x this)
An extra time saving potential is caching type sizes. They are
well-known, and seldom change, esp. in CI. GHA/Windows jobs spend 8-17
seconds per job on these ~12 feature checks. ~5s on Cygwin/MSYS2. Couple
of seconds on other platforms. (This PR doesn't make this optimization.)
Another opportunity is doing the same for autotools, which typically
spends more time in the configuration step than cmake.
[1] Xcode job restored as a
follow-up to be5f20202c#16302
[2] GHA/macos cmake configure times in seconds:
Job | Bef. | After | Gain
:----------------------------------------------- | ----: | ----: | ----:
CM clang GnuTLS !ldap krb5 | 21.2 | 4.5 | 16.7
CM clang LibreSSL !ldap heimdal c-ares +examples | 13.3 | 3.9 | 9.4
CM clang OpenSSL +static libssh +examples | 20.0 | 4.6 | 15.4
CM clang OpenSSL IDN clang-tidy~ (w/chkprefill) | 15.7 | 18.6 | -2.9
CM clang OpenSSL gsasl rtmp AppleIDN | 25.0 | 4.7 | 20.3
CM clang OpenSSL torture !FTP | 15.3 | 4.5 | 10.8
CM clang OpenSSL torture FTP | 25.0 | 5.9 | 19.1
CM clang SecureTransport debug | 18.0 | 3.8 | 14.2
CM clang macos-13 SecureTransport | 45.8 | 12.4 | 33.4
CM clang macos-14 SecureTransport | 15.8 | 4.6 | 11.2
CM clang macos-15 SecureTransport | 26.8 | 6.1 | 20.7
CM clang mbedTLS openldap brotli zstd | 15.1 | 6.5 | 8.6
CM clang wolfSSL !ldap brotli zstd | 27.0 | 4.4 | 22.6
CM gcc-12 GnuTLS !ldap krb5 | 39.1 | 8.7 | 30.4
CM gcc-12 LibreSSL !ldap heimdal c-ares +examples| 23.8 | 7.2 | 16.6
CM gcc-12 OpenSSL +static libssh +examples | 20.7 | 8.5 | 12.2
CM gcc-12 OpenSSL gsasl rtmp AppleIDN | 23.1 | 10.1 | 13.0
CM gcc-12 SecureTransport debug | 21.1 | 4.8 | 16.3
CM gcc-12 mbedTLS openldap brotli zstd | 21.4 | 5.8 | 15.6
CM gcc-12 wolfSSL !ldap brotli zstd | 21.1 | 6.9 | 14.2
CM gcc-14 macos-13 SecureTransport | 61.9 | 18.7 | 43.2
CM gcc-14 macos-14 SecureTransport | 30.5 | 6.4 | 24.1
CM gcc-14 macos-15 SecureTransport | 32.7 | 8.4 | 24.3
CM llvm@15 GnuTLS !ldap krb5 | 21.1 | 7.5 | 13.6
CM llvm@15 LibreSSL !ldap heimdal c-ares +exampl~| 24.6 | 6.8 | 17.8
CM llvm@15 OpenSSL +static libssh +examples | 19.0 | 6.4 | 12.6
CM llvm@15 OpenSSL gsasl rtmp AppleIDN | 19.0 | 8.2 | 10.8
CM llvm@15 SecureTransport debug | 18.0 | 5.4 | 12.6
CM llvm@15 macos-13 SecureTransport | 66.2 | 25.7 | 40.5
CM llvm@15 macos-14 SecureTransport | 31.9 | 6.1 | 25.8
CM llvm@15 mbedTLS openldap brotli zstd | 19.5 | 8.9 | 10.6
CM llvm@15 wolfSSL !ldap brotli zstd | 24.3 | 5.9 | 18.4
CM llvm@18 macos-15 SecureTransport | 33.8 | 6.4 | 27.4
Total | 856.8 | 257.3 | 599.5
Before: https://github.com/curl/curl/actions/runs/13311042735/job/37173478424
After: https://github.com/curl/curl/actions/runs/13313927119/job/37183206426?pr=15841
[3] iOS:
Before: https://github.com/curl/curl/actions/runs/13326401704?pr=15841
After: https://github.com/curl/curl/actions/runs/13332177764?pr=15841
[4] detection results exposed indirectly in `curl_config.h`:
- `HAVE_FILE_OFFSET_BITS` via `_FILE_OFFSET_BITS`
- `HAVE_GETHOSTBYNAME_R_*_REENTRANT` via `NEED_REENTRANT`
- `HAVE_SOCKADDR_IN6_SIN6_ADDR` via `USE_IPV6`
Closes#15841
e7adf3e837