ABI Lens

A VS Code extension to help C++ developers inspect their Application Binary Interface (ABI) inline struct/class memory layouts, v-tables, and calling conventions at a glance.

Features

• Hover Inspection
  Hover over any user-defined struct or class to see its record layout: field offsets, sizes, alignment, padding.

• File Summary
  Run “ABI Lens: Show File ABI” to output layouts for all user-defined types in the active file into an output channel.

• Markdown Tooltips & Output
  ABI details are rendered as Markdown code blocks in both hover tooltips and the ABI Lens output channel.

Usage

1. Open the Command Palette
   Press Ctrl+Shift+P (Windows/Linux) or Cmd+Shift+P (macOS).

2. Type ABI Lens:
   Then pick “Show File ABI” to generate a summary for all user-defined types in the current file.

3. Hover in editor
   Open any C/C++ file (.cpp, .h, etc.) and hover over a user-defined struct or class name to see its inline ABI layout.

Requirements

• Clang/LLVM with clang++ on your PATH
  • Linux:

    sudo apt install clang llvm
    

  • macOS:

    brew install llvm
    export PATH="$(brew --prefix llvm)/bin:$PATH"
    

  • Windows:
    Install LLVM via the official installer or Chocolatey:

    choco install llvm
    

Extension Settings

This extension contributes no customizable settings.

Known Issues

• Only user-defined types in the active file are shown; hovering on library or standard types is ignored.
• Very large files with many types may take a few seconds to process the layout dump.
• Requires a successful syntax-only compile; files with errors will not produce layouts.
• User-defined types must actually be used in the code; otherwise, the compiler may optimize them away and no information will be available.

Changelog

0.1.0

• Initial release
  • Hover Inspection for user types
  • Show File ABI summary command
  • Custom type filtering
  • Markdown-formatted tooltips and output channel

Enjoy crystal-clear ABI insights!