[Mac] Secondary WebKit processes get re-exec'ed twice when running under ASan

• Component: WebKit2
• Status: RESOLVED FIXED

[Alexey Proskuryakov]

ASan needs to have its dynamic library inserted using DYLD_INSERT_LIBRARIES. When an ASanified binary is loaded and notices that this hasn't been done, it re-execs the process with environment updated.

We already do a re-exec in Development builds of WebKit processes, pretty much for the same reason. Getting two re-execs it very annoying in debugging, because the debugger stops on exec. So if you wait to attach to com.apple.WebKit.WebContent.Development, you need to hit continue twice when it launches.

[Alexey Proskuryakov]

Created attachment 244143 [details]
proposed fix

As a separate fix, we'll also need to insert the library into the main process in run-webkit-tests and in run-safari. Having an extra re-exec in secondary process is the more annoying problem, because various IPC timeouts can pass while one resumes the process.

[Alexey Proskuryakov]

Created attachment 244144 [details]
proposed fix

Better behavior for release builds in the theoretical case where ASan library name becomes different.

It's not a big problem to re-exec in release build, because it's probably not being debugged. So it doesn't have to be fatal if we can't find the library.

[Alexey Proskuryakov]

Created attachment 244167 [details]
proposed fix

Structured it slightly nicer.

[WebKit Commit Bot]

Attachment 244167 [details] did not pass style-queue:


ERROR: Source/WebKit2/UIProcess/Launcher/mac/ProcessLauncherMac.mm:97:  One line control clauses should not use braces.  [whitespace/braces] [4]
Total errors found: 1 in 2 files


If any of these errors are false positives, please file a bug against check-webkit-style.

[Alexey Proskuryakov]

Committed <http://trac.webkit.org/r178043>, build fix in <http://trac.webkit.org/r178044>.

[Alexey Proskuryakov]

<rdar://problem/19431848>