Cleaned up the code and we now also dump the dynamic object for the malloc block. Using this on the lldb/test/lang/objc/foundation test we can see this in action:

First we can load the module:

(lldb) command script import /Volumes/work/gclayton/Documents/src/lldb/examples/darwin/heap_find/heap.py
Loading "/Volumes/work/gclayton/Documents/src/lldb/examples/darwin/heap_find/libheap.dylib"...ok
Image 0 loaded.
"heap_ptr_refs" and "heap_cstr_refs" commands have been installed, use the "--help" options on these commands for detailed help.


Lets take a look at the variable "my":

(lldb) fr var *my
(MyString) *my = {
  MyBase = {
    NSObject = {
      isa = MyString
    }
    propertyMovesThings = 0
  }
  str = 0x0000000100301a60
  date = 0x0000000100301e60
  _desc_pauses = NO
}


We can see that this contains an ivar "str" which has a pointer value of "0x0000000100301a60". Lets search the heap for this pointer and see what we find:

(lldb) heap_ptr_refs 0x0000000100301a60
found pointer 0x0000000100301a60: block = 0x103800270, size = 384, offset = 168, type = 'void *'
found pointer 0x0000000100301a60: block = 0x100301cf0, size = 48, offset = 16, type = 'MyString *', ivar = 'str'
(MyString) *addr = {
  MyBase = {
    NSObject = {
      isa = MyString
    }
    propertyMovesThings = 0
  }
  str = 0x0000000100301a60
  date = 0x0000000100301e60
  _desc_pauses = NO
}
found pointer 0x0000000100301a60: block = 0x100820000, size = 4096, offset = 96, type = (autorelease object pool)
found pointer 0x0000000100301a60: block = 0x100820000, size = 4096, offset = 104, type = (autorelease object pool)


Note that it used dynamic type info to find that it was in "MyString" at offset 16 and it also found the ivar "str"!

We can also look for C string values on the heap. Lets look for "a.out":

(lldb) heap_cstr_refs "a.out"
found cstr a.out: block = 0x10010ce00, size = 96, offset = 85, type = '__NSCFString *'
found cstr a.out: block = 0x100112d90, size = 80, offset = 68, type = 'void *'
found cstr a.out: block = 0x100114490, size = 96, offset = 85, type = '__NSCFString *'
found cstr a.out: block = 0x100114530, size = 112, offset = 97, type = '__NSCFString *'
found cstr a.out: block = 0x100114e40, size = 32, offset = 17, type = '__NSCFString *'
found cstr a.out: block = 0x100114fa0, size = 32, offset = 17, type = '__NSCFString *'
found cstr a.out: block = 0x100300780, size = 160, offset = 128, type = '__NSCFData *'
found cstr a.out: block = 0x100301a60, size = 112, offset = 97, type = '__NSCFString *'
found cstr a.out: block = 0x100821000, size = 4096, offset = 100, type = 'void *'

We see we have some objective C classes that contain this, so lets "po" all of the results by adding the --po option:

(lldb)  heap_cstr_refs a.out --po
found cstr a.out: block = 0x10010ce00, size = 96, offset = 85, type = '__NSCFString *'
  (__NSCFString *) 0x10010ce00 /Volumes/work/gclayton/Documents/src/lldb/test/lang/objc/foundation/a.out

found cstr a.out: block = 0x100112d90, size = 80, offset = 68, type = 'void *'
found cstr a.out: block = 0x100114490, size = 96, offset = 85, type = '__NSCFString *'
  (__NSCFString *) 0x100114490 /Volumes/work/gclayton/Documents/src/lldb/test/lang/objc/foundation/a.out

found cstr a.out: block = 0x100114530, size = 112, offset = 97, type = '__NSCFString *'
  (__NSCFString *) 0x100114530 Hello from '/Volumes/work/gclayton/Documents/src/lldb/test/lang/objc/foundation/a.out'

found cstr a.out: block = 0x100114e40, size = 32, offset = 17, type = '__NSCFString *'
  (__NSCFString *) 0x100114e40 a.out.dSYM

found cstr a.out: block = 0x100114fa0, size = 32, offset = 17, type = '__NSCFString *'
  (__NSCFString *) 0x100114fa0 a.out

found cstr a.out: block = 0x100300780, size = 160, offset = 128, type = '__NSCFData *'
  (__NSCFData *) 0x100300780 <48656c6c 6f206672 6f6d2027 2f566f6c 756d6573 2f776f72 6b2f6763 6c617974 6f6e2f44 6f63756d 656e7473 2f737263 2f6c6c64 622f7465 73742f6c 616e672f 6f626a63 2f666f75 6e646174 696f6e2f 612e6f75 742700>

found cstr a.out: block = 0x100301a60, size = 112, offset = 97, type = '__NSCFString *'
  (__NSCFString *) 0x100301a60 Hello from '/Volumes/work/gclayton/Documents/src/lldb/test/lang/objc/foundation/a.out'

found cstr a.out: block = 0x100821000, size = 4096, offset = 100, type = 'void *'