[webkit-dev] PSA: on make targets "testing" and "release+assert", ASSERT_ENABLED, and NDEBUG
mark.lam at apple.com
Wed Jan 8 15:11:31 PST 2020
Ever wanted to run tests with Debug ASSERTs enabled but the speed of the Debug build is so slow that it is a drag on your productivity? Well, now you can get a faster testing build in one of two ways:
1. Build WebKit with "make testing” (or “make t”)
2. Build WebKit with “make release+assert” (or “make ra”)
The “testing” make target builds a Debug build with the clang optimization level forced to -O3.
The forcing of -O3 is achieved using "Tools/Scripts/set-webkit-configuration --force-optimization-level=O3”. See trac.webkit.org/r254080 <http://trac.webkit.org/r254080>.
With this configuration, you can run JSC tests or layout tests like normal, except it will run faster.
How much faster?
Using a normal debug build, the JSC tests takes about 6 hours to complete.
Using the “testing” build, the JSC tests takes less than 30 minutes to complete.
The “release+assert” make target builds a Release build with ASSERT_ENABLED=1 defined.
With this configuration, you can run JSC tests.
Currently, if you run this on the layout tests, you will see a lot of ASSERT failures, which brings us to ...
#if ASSERT_ENABLED vs #ifndef NDEBUG
Since trac.webkit.org/r254087 <http://trac.webkit.org/r254087>, the ASSERT_DISABLED flag has been completely replaced with ASSERT_ENABLED.
For code that guards fields and code needed to support debug ASSERTs, please use #if ASSERT_ENABLED going forward.
Please do NOT use #ifndef NDEBUG.
1. Build WebKit with “make release+assert”.
2. Run "Tools/Scripts/run-webkit-tests —release”.
3. Look for tests that crashed with “ASSERTION FAILED: “ in the crash log e.g. "ASSERTION FAILED: m_tokenizer.isInDataState()”.
4. Find anything that the assertion depends on which is guarded by #ifndef NDEBUG, and replace it with #if ASSERT_ENABLED.
5. Re-build WebKit and retest.
In general, there is probably no reason to ever use #ifndef NDEBUG. Apart from assertion code, logging (and possibly other) code may also be affected by this same issue.
The “testing” and “release+assert” make targets are available to use starting in trac.webkit.org/r254227 <http://trac.webkit.org/r254227>. I only tested these make targets on Mac. For other ports, some work may be required to get the builds configured similarly.
One caution about using the “testing” target: it configures the build environment using set-webkit-configuration. That means unless you clear the configuration using "set-webkit-configuration --force-optimization-level=none”, it will force the clang optimization level to -O3 for all builds that follow, debug or release. This is similar to how "set-webkit-configuration --asan” works. Alternatively, you can also do "set-webkit-configuration —reset” to clear all configurations set using set-webkit-configuration.
If typing “--force-optimization-level” is too long and painful, “--force-opt” also works.
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