* [https://developer.apple.com/library/mac/documentation/ToolsLanguages/Conceptual/Xcode_Overview/About_Xcode/about.html#//apple_ref/doc/uid/TP40010215-CH3-SW1 General information on using Xcode]

= Debugging WebKit2 =

== Method #1 ==

 1. Make sure '''Use WebKit2 for New Windows''' option is selected in Safari’s '''Debug'''
 2. Open `WebKit2.xcodeproj` and make sure that the WebProcess is set to the Active Executable
 3. Control-click the `WebProcess` executable and choose '''Get Info'''
 4. In the Debugging tab, select '''Wait for next launch/push notification'''
 5. Choose '''Run ► Debug'''
 6. A dialog will appear saying: “Waiting for WebProcess to launch…”
 7. Open `Safari.xcodeproj` '''Run ► Debug'''
 8. The WebProcess will break in the debugger, and you’ll probably have to continue at least once before normal execution resumes

You’re now debugging both the `UIProcess` and the `WebProcess`. Your breakpoints in either should be work accordingly.


== Method #2 ==

 1. Open the Xcode projects for Safari and WebCore (or WebKit2, or whatever)
 2. From the Safari project, '''Run'''
 3. From the WebCore project, choose '''Run ► Attach to Process''', and choose the `WebProcess`
 4. Let `gdb` do its thing, and Continue

You’re now debugging the `WebProcess`.  ''('''Note:''' I've had issues with `gdb` using this method.)''


= Debugging DumpRenderTree =

= Debugging WebKitTestRunner =

== Prevent Safari from complaining about web process hangs when debugging ==

 1. Control-click the Safari executable and choose '''Get Info'''
 2. Select the '''Arguments''' tab
 3. Beneath the list '''Variables to be set in the environment''', click the “`✚`” button
 4. Add the following item:
  * '''Name:''' `DebugInitialDelayForUnresponsiveWebProcess` 
  * '''Value:''' `99999999`

== To debug a web process crash on launch: ==

 1. Edit `WebKit2/UIProcess/Launcher/mac/ProcessLauncherMac.mm`
 2. Search for `SIGCONT`
 3. Remove the line of code that sends `SIGCONT` to the web process, then build
 4. In Terminal: 
  a. launch `gdb`, then type `attach WebProcess` — OR 
  b. in Xcode select '''Run  ► Attach to Process  ► Process ID...''' and type the WebProcess’s process ID
 5. Once attached:
  a. In `gdb` type `continue«enter»` — OR 
  b. In Xcode select '''Run ► Continue'''

== To debug a web process using Instruments/DTrace: ==

If you’re having trouble attaching to the WebProcess, try disabling the sandbox:

{{{defaults write com.apple.WebProcess DisableSandbox YES}}}