lldb-toybox 🧰

Various LLDB extensions that make debugging C++ code a bit more seamless:

Features

Naturally ordered hash table contents

The native LLDB data formatters enumerate hash table based containers in iteration order. This can be inconvenient for large registries where a simple integral key is mapped to a more complex type: finding the appropriate entry is difficult, as the elements are listed in iteration order by default.

Type formatter implementations in lldb-toybox print elements in their natural order if the key of an entry is convertible to an integral type:

Native LLDB	lldb-toybox
(std::unordered_map<int, int>) size=8 { [0] = (first = 7, second = 7) [1] = (first = 6, second = 6) [2] = (first = 5, second = 5) [3] = (first = 4, second = 4) [4] = (first = 3, second = 3) [5] = (first = 2, second = 2) [6] = (first = 1, second = 1) [7] = (first = 0, second = 0) } (std::unordered_set<int>) size=8 { [0] = 7 [1] = 6 [2] = 5 [3] = 4 [4] = 3 [5] = 2 [6] = 1 [7] = 0 }	(std::unordered_map<int, int>) size=8 { int(0) = 0 int(1) = 1 int(2) = 2 int(3) = 3 int(4) = 4 int(5) = 5 int(6) = 6 int(7) = 7 } (std::unordered_set<int>) size=8 { int(0) = 0 int(1) = 1 int(2) = 2 int(3) = 3 int(4) = 4 int(5) = 5 int(6) = 6 int(7) = 7 }

Extended node_type support

Native LLDB formatters lack support for various node_types for containers. lldb-toybox adds it's own implementation:

(std::unordered_map<int, int>::node_type) <Empty node>

(std::unordered_map<int, int>::node_type) {
  stored = (first = 100, second = 1000)
}

Extended iterator support

Native LLDB formatters iterator support is extended to provide better summaries.

(absl::container_internal::raw_hash_set<...>::iterator) <End iterator>

(absl::container_internal::raw_hash_set<...>::iterator) {
  pointee = (first = 200, second = 2000)
}

Supported types

libc++ std::unordered_(set|map)

Implemented by hash_container_support.py, enabled by the lldb-toybox.libcxx and lldb-toybox.libcxx-overrides type categories.

• Support for naturally ordered elements (overrides native implementation!)
• Support for node_type

Warning

Replacing the native data formatter implementation of LLDB for libc++ types with a Python script comes with a slight performance impact, and has a risk of breaking for future libc++ versions.

If you are experiencing issues you can disable the override through the lldb-toybox.libcxx-overrides type category:
type category disable lldb-toybox.libcxx-overrides

Abseil absl::(node|flat)_hash_(set|map)

Implemented by hash_container_support.py, enabled by the lldb-toybox.abseil type category.

• Support for naturally ordered elements
• Support for iterator and const_iterator
• Support for node_type