NASM x86/x86_64 IntelliSense

NASM IntelliSense is a VS Code extension that adds (Simple) language-server powered editing for NASM-style x86 and x86_64 assembly:

• Autocomplete for instructions, registers, directives, and in-file labels/constants.
• Hover docs for core instructions, registers, and directives.
• Diagnostics by running the local nasm assembler.
• Go to Definition for labels and equ constants.
• Syntax highlighting via a NASM TextMate grammar.

This extension is built on the Language Server Protocol (LSP) with a dedicated Node-based language server.

Example

Features

• Autocomplete

  • Instructions: common x86/x86_64 instructions (mov, add, cmp, jmp, call, ret, syscall, etc.).
  • Registers: 8/16/32/64-bit GPRs (rax, eax, ax, al, etc.), segment registers, and flags.
  • Directives: section, segment, global, extern, equ, %define, db/dw/dd/dq, resb/resw/resd/resq, and more.
  • Symbols: labels (_start:) and equ-style constants from the current document.

• Hover Documentation

  • Hover over an instruction to see:
    • A NASM-styled usage line (e.g. mov dest, src).
    • A short description.
  • Hover over a register to see its size and category.
  • Hover over a directive for a description.
  • Hover over a label/constant for a short classification (label vs equ).

• Diagnostics (error highlighting)

  • Uses your local nasm installation to compile the file to a temporary .asm and parse its error/warning messages.
  • Reports NASM errors and warnings as editor diagnostics with squiggles.
  • Fully optional and configurable (see below).

• Go to Definition

  • F12 / “Go to Definition” on:
    • A label use jumps to the label declaration.
    • A constant use jumps to its equ definition.
  • Currently scoped to the current file.

• Syntax Highlighting

  • TextMate grammar for nasm:
    • Comments (;).
    • Labels.
    • Instructions.
    • Directives.
    • Registers.
    • Numeric literals (hex/decimal).
    • Strings (single and double quotes).

BTW, TextMate grammar is what vscode uses to colourise tokens.

Configuration

All settings live under the nasmIntellisense section:

• nasmIntellisense.nasmPath (string, default: "nasm"):

  • Path to the nasm executable.
  • Override this if nasm is not on your PATH or has a nonstandard name.

• nasmIntellisense.enableDiagnostics (boolean, default: true):

  • If true, the server runs nasm to provide error diagnostics.
  • If false, no diagnostics are produced, but autocomplete, hover, go to definition, and highlighting still work.
  • You can toggle this at any time using the “NASM IntelliSense: Toggle Diagnostics” command.

• nasmIntellisense.diagnosticsOnSaveOnly (boolean, default: true):

  • If true, diagnostics are only run on save.
  • If false, diagnostics may run after edits (debounced on the server side).

• nasmIntellisense.arch ("x86" | "x86_64", default: "x86_64"):

  • Architecture used when invoking nasm:
    • "x86_64" → -f elf64
    • "x86" → -f elf32

Commands

• NASM IntelliSense: Restart Language Server

  • Stops and restarts the language server.
  • Useful after changing configuration or updating nasm.

• NASM IntelliSense: Show Server Status

  • Shows whether the language server is currently running.

• NASM IntelliSense: Toggle Diagnostics

  • Flips nasmIntellisense.enableDiagnostics for the current workspace.
  • Use this to quickly turn off error squiggles while keeping:
    • Syntax highlighting.
    • Completions.
    • Hover docs.
    • Go to Definition.

Requirements

• VS Code on a supported version (see engines.vscode in package.json).
• Node.js for extension development (if you are building from source).
• NASM assembler (optional, but required for diagnostics):
  • Install nasm and ensure it is on your PATH, or set nasmIntellisense.nasmPath.

Building and Running (from source)

• Install dependencies:

npm install
cd server
npm install
cd ..

• Compile the extension:

npm run compile

• Debug / Run Extension:
  • Open the project folder in VS Code.
  • Use the “Run Extension” launch configuration (F5).
  • In the Extension Development Host that opens:
    • Open examples/test.asm, or any .asm / .nasm file.
    • Start editing to see completions, hover info, highlighting, and (if enabled) diagnostics.

Known Quirks and Limitations

• Partial instruction set

  • The built-in instruction database covers common core instructions, not the full x86/x86_64 ISA.
  • Completions and hover docs for very specialized or rare mnemonics may be missing.

• Per-file symbol navigation only

  • “Go to Definition” currently works within a single file.
  • Cross-file symbol resolution (e.g. across multiple .asm files with extern/global) is not implemented.

• Diagnostics rely on NASM

  • If nasm is not installed or not found:
    • No diagnostics will appear.
    • You should see a one-time warning from the extension.
  • The extension does not ship its own assembler; it only shells out to your local nasm.

• Diagnostics granularity

  • NASM error messages are mapped to entire lines.
  • Column-level ranges are approximated to the full line, so squiggles may appear under the whole line rather than the exact token.

Contributing / Extending

• Extend the instruction set

  • Add or refine instructions, registers, and directives in server/src/nasmData.ts.

• Improve parsing

  • Enhance server/src/parser.ts if you want more accurate label/constant detection or future features like document symbols.

• Add more language features

  • The language server is built with vscode-languageserver; you can extend it with:
    • Signature help.
    • Document symbols (outline).
    • References and rename.

I am so Sorry

This extension was made with help from AI- claude and cursor.