ABI Explorer for VS Code

See how your C and C++ structs are laid out, with your project's own compile flags and target:

• Hover a struct's name for its size, alignment, padding and a byte map; hover a member for its offset. Uses of a type hover the same way, library types included: std::string, std::vector<int>.
• A warning on a struct whose member order wastes space, saying how small another order would make it. A struct laid out on purpose (a wire format, say) keeps its order with // abi-explorer: keep order above it, which the warning's other fix, Keep this member order, writes.
• Refactorings on a struct (the light bulb, or Ctrl+.): Reorder members by alignment, the quick fix for that warning, moves the member lines into the order that packs tightest (positional initializers such as {'a', 1.5} elsewhere then need the new order too); Pin layout with static_assert adds assertions of its size, alignment and (where the file includes <cstddef>) member offsets, so a change that moves them stops the build.
• Struct Layout view in the Explorer, following the caret, with a member table you can click to jump, and a button that copies the layout as text.

Flags come from, in order: CMake Tools, compile_commands.json (searched like clangd does, or the directory clangd or the C/C++ extension is told to use), compile_flags.txt, then abiExplorer.fallbackFlags. System headers are found by asking the project's compiler, the way clangd's --query-driver does; MSVC (cl.exe, clang-cl) projects are supported.

The layout engine (clang compiled to WebAssembly, about 50 MB) is downloaded once on first use and shared by every editor that uses it.

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