On Nov 4, 2018, at 3:43 AM, Frank Jaeger <fjaeger77@outlook.com> wrote:

Hello. First of all I'm really sorry if this is the wrong mailing list to post to, webkit-help would have probably been better but it doesn't seem very active.

I run into some problems while trying to use the dump-class-layout script (found in Tools/Scripts/). I built WebKit using the build-webkit script with the --debug flag.

After building, I tried to run the dump-class-layout script with the following arguments:

./Tools/Scripts/dump-class-layout --architecture=x86_64 -c Debug JavaScriptCore JSString

I also tried different frameworks and classes. The script always fails telling me that "no type matches x in y" where x is the class name I used in the run and y is the framework name.

Why is this happening? The script is correctly finding the built and symbolicated framework image, so why is it not working properly? Thanks in advance.

This just worked for me on Mojave.

$ ./Tools/Scripts/dump-class-layout --architecture=x86_64 -c Debug JavaScriptCore JSString
  +0 < 24> JSString
  +0 <  8>     JSC::JSCell JSC::JSCell
  +0 <  1>         JSC::HeapCell JSC::HeapCell
  +0 <  4>       JSC::StructureID m_structureID
  +4 <  1>       JSC::IndexingType m_indexingTypeAndMisc
  +5 <  1>       JSC::JSType m_type
  +6 <  1>       JSC::TypeInfo::InlineTypeFlags m_flags
  +7 <  1>       JSC::CellState m_cellState
  +8 <  4>   unsigned int m_length
 +12 <  2>   uint16_t m_flags
 +14 <  2>   <PADDING: 2 bytes>
 +16 <  8>     WTF::String m_value
 +16 <  8>         WTF::RefPtr<WTF::StringImpl, WTF::DumbPtrTraits<WTF::StringImpl> > m_impl
 +16 <  8>           WTF::DumbPtrTraits<WTF::StringImpl>::StorageType m_ptr
Total byte size: 24
Total pad bytes: 2
Padding percentage: 8.33 %

Could you show your exact output?

Perhaps opening a Bugzilla bug and putting the details there would be best. I’d be interested to know your version of Xcode/lldb (lldb --version, xcodebuild -version).

- Joe