LLDB script for dumping C++ structs/classes and variables layout in memory
Works with Xcode/Android Studio, Visual Studio Code (For Visual Studio Code, use binary from https://github.com/vadimcn/vscode-lldb)
After start lldb, use command:
command script import ~/PATH_TO_SCRIPT/dump_class_laouyt.py to install commands layout and layoutvar
Example of usage:
(lldb) layoutvar aaa
std::__1::map<int, int, std::__1::less<int>, SimpleAllocator<std::__1::pair<const int, int> > >
+0 < 24> std::__1::map<int, int, std::__1::less<int>, SimpleAllocator<std::__1::pair<const int, int> > >
+0 < 24> std::__1::map<int, int, std::__1::less<int>, SimpleAllocator<std::__1::pair<const int, int> > >::__base __tree_
+0 < 8> std::__1::__tree<std::__1::__value_type<int, int>, std::__1::__map_value_compare<int, std::__1::__value_type<int, int>, std::__1::less<int>, true>, SimpleAllocator<std::__1::__value_type<int, int> > >::__iter_pointer __begin_node_
+8 < 8> std::__1::__compressed_pair<std::__1::__tree_end_node<std::__1::__tree_node_base<void *> *>, SimpleAllocator<std::__1::__tree_node<std::__1::__value_type<int, int>, void *> > > __pair1_
+8 < 8> std::__1::__compressed_pair_elem<std::__1::__tree_end_node<std::__1::__tree_node_base<void *> *>, 0, false> std::__1::__compressed_pair_elem<std::__1::__tree_end_node<std::__1::__tree_node_base<void *> *>, 0, false>
+8 < 8> std::__1::__tree_end_node<std::__1::__tree_node_base<void *> *> __value_
+8 < 8> std::__1::__tree_end_node<std::__1::__tree_node_base<void *> *>::pointer __left_
+8 < 1> std::__1::__compressed_pair_elem<SimpleAllocator<std::__1::__tree_node<std::__1::__value_type<int, int>, void *> >, 1, true> std::__1::__compressed_pair_elem<SimpleAllocator<std::__1::__tree_node<std::__1::__value_type<int, int>, void *> >, 1, true>
+8 < 1> SimpleAllocator<std::__1::__tree_node<std::__1::__value_type<int, int>, void *> > SimpleAllocator<std::__1::__tree_node<std::__1::__value_type<int, int>, void *> >
+8 < 1> std::__1::allocator<std::__1::__tree_node<std::__1::__value_type<int, int>, void *> > std::__1::allocator<std::__1::__tree_node<std::__1::__value_type<int, int>, void *> >
+16 < 8> std::__1::__compressed_pair<unsigned long, std::__1::__map_value_compare<int, std::__1::__value_type<int, int>, std::__1::less<int>, true> > __pair3_
+16 < 8> std::__1::__compressed_pair_elem<unsigned long, 0, false> std::__1::__compressed_pair_elem<unsigned long, 0, false>
+16 < 8> unsigned long __value_
+16 < 1> std::__1::__compressed_pair_elem<std::__1::__map_value_compare<int, std::__1::__value_type<int, int>, std::__1::less<int>, true>, 1, true> std::__1::__compressed_pair_elem<std::__1::__map_value_compare<int, std::__1::__value_type<int, int>, std::__1::less<int>, true>, 1, true>
+16 < 1> std::__1::__map_value_compare<int, std::__1::__value_type<int, int>, std::__1::less<int>, true> std::__1::__map_value_compare<int, std::__1::__value_type<int, int>, std::__1::less<int>, true>
+16 < 1> std::__1::less<int> std::__1::less<int>
+16 < 1> std::__1::binary_function<int, int, bool> std::__1::binary_function<int, int, bool>
Total byte size: 24
Total pad bytes: 0
(lldb) layout "std::__1::__tree_node<std::__1::__value_type<int, int>, void *>"
+0 < 40> std::__1::__tree_node<std::__1::__value_type<int, int>, void *>
+0 < 32> std::__1::__tree_node_base<void *> std::__1::__tree_node_base<void *>
+0 < 8> std::__1::__tree_node_base_types<void *>::__end_node_type std::__1::__tree_node_base_types<void *>::__end_node_type
+0 < 8> std::__1::__tree_end_node<std::__1::__tree_node_base<void *> *>::pointer __left_
+8 < 8> std::__1::__tree_node_base<void *>::pointer __right_
+16 < 8> std::__1::__tree_node_base<void *>::__parent_pointer __parent_
+24 < 1> bool __is_black_
+25 < 3> <PADDING: 3 bytes>
+28 < 8> std::__1::__tree_node<std::__1::__value_type<int, int>, void *>::__node_value_type __value_
+28 < 8> std::__1::__value_type<int, int>::value_type __cc
+28 < 4> const int first
+32 < 4> int second
+36 < 4> <PADDING: 4 bytes>
Total byte size: 40
Total pad bytes: 7
Padding percentage: 17.50 %
Issues: Script shows incorrect paddings between virtual ancestors of the object
Additional info (in russian) - https://spiiin.github.io/blog/1170009669/