Blot Vim Plugin

A Vim plugin that integrates Blot, a compiler-explorer clone that works with your local toolchain and project, with Vim for C++ development.

Features

• Display assembly output in a split window alongside your C++ source
• Highlight source-to-assembly line mappings
• Automatic blot executable detection
• Configurable key mappings

Installation

Using vim-plug

Add to your .vimrc:

Plug 'adromanov/vim-blot'

Manual Installation

Copy the plugin files to your Vim configuration directory:

cp -r ftplugin/ ~/.vim/ftplugin/
cp -r plugin/ ~/.vim/plugin/

Using Pathogen

cd ~/.vim/bundle
git clone https://github.com/adromanov/vim-blot

Usage

Commands

• :BlotShowAssembly - Generate and display assembly for the current C++ file
• :BlotHighlight - Highlight assembly lines corresponding to current source line
• :BlotClose - Close the assembly buffer

Default Key Mappings

• <leader>ba - Show assembly
• <leader>bh - Highlight current line mappings
• <leader>bc - Close assembly buffer

Configuration

Variables

" Set custom blot executable path (default: 'blot')
let g:blot_executable = '/path/to/blot'

" Disable default key mappings
let g:blot_no_mappings = 1

" Enable auto-highlighting when cursor moves (experimental)
let g:blot_auto_highlight = 1

Custom Key Mappings

" Disable default mappings
let g:blot_no_mappings = 1

" Set your own mappings
nnoremap <F5> :BlotShowAssembly<CR>
nnoremap <F6> :BlotHighlight<CR>
nnoremap <F7> :BlotClose<CR>

How It Works

1. The plugin runs blot --json <filename> on the current C++ file
2. Parses the JSON output containing assembly lines and line mappings
3. Creates a new buffer with assembly syntax highlighting
4. Provides commands to highlight corresponding assembly lines

Requirements

• Vim with JSON support (Vim 8.0+ or Neovim)
• Built blot executable (either in project build-Debug/ or in PATH)
• C++ project with compile_commands.json (for blot to work)

Troubleshooting

• "Blot executable not found": Ensure blot is built or set g:blot_executable
• "Blot failed": Check that your C++ file is in a project with compile_commands.json
• No assembly output: Verify the file compiles successfully with your build system