x86 AT&T Assembly (GAS) — Syntax Highlighting for VS Code

Rich syntax highlighting for x86 assembly written in AT&T/GAS (GNU Assembler) style.

Features

• Instructions — Full coverage of x86 data movement, arithmetic, logic, control flow, string operations, and more, all with size suffix support (b, w, l, q)
• Registers — 64/32/16/8-bit general purpose, segment, control/debug, FPU, SSE/AVX (xmm/ymm/zmm), and flags registers
• Immediates — $-prefixed decimal, hex, binary, octal, and symbol references
• Directives — GAS section, data, alignment, macro, conditional, and CFI directives
• Labels — Function and local label definitions
• Comments — Line (#) and block (/* */) comments
• Strings — Double-quoted strings with escape sequences and single-quoted characters
• SSE/AVX — Common SIMD instruction mnemonics with optional v prefix

Supported File Extensions

• .s
• .S
• .asm

Example

    .section .text
    .global _start

_start:
    movq $1, %rax       # syscall: write
    movq $1, %rdi       # fd: stdout
    leaq msg(%rip), %rsi
    movq $13, %rdx      # length
    syscall

    movq $60, %rax      # syscall: exit
    xorq %rdi, %rdi
    syscall

    .section .data
msg:
    .asciz "Hello, world!"

Theme Compatibility

This extension uses standard TextMate scope names, so it works out of the box with any VS Code color theme — Dark+, One Dark Pro, Dracula, Catppuccin, Gruvbox, and others.

Installation

Search for x86 AT&T Assembly (GAS) in the VS Code Extensions panel, or install from the Visual Studio Marketplace.

Contributing

Found a missing instruction or a highlighting bug? Open an issue or pull request on GitHub.

License

MIT