FASM2 Studio

Editor tooling for flat assembler g (fasmg, distributed as "fasm2"), with source compatibility for classic flat assembler 1. This extension drives whatever fasm2/fasm1 (and, for debugging, gdb/lldb) you already have installed — it doesn't bundle a compiler or a debugger, the same way a C/C++ or Rust extension works with your existing toolchain rather than shipping its own.

What you get

Open a .asm, .inc, .fasm, or .fas file and it's syntax-highlighted immediately. Behind that, a language server parses your project and gives you:

Completion and hover for instructions, registers, directives, format/segment/section sub-keywords (ELF64, executable, DLL, ...), operand-size/addressing qualifiers (byte, dword, ptr, near, ...), and your own labels/macros/constants.
Go to definition, find references, rename, and workspace symbol search that work across your whole project — not just the open file. Files are indexed once in the background and kept in sync as you edit, so this stays fast on real-sized projects.
Signature help while you're filling in a macro call.
Live diagnostics from the real compiler — errors and warnings come from actually running fasm2/fasm1 in the background as you type, parsed from its real output, not a hand-rolled approximation of its rules. Works for unsaved buffers too.

FASM: Build, FASM: Build and Run, and FASM: Run compile and execute the active file. The extension finds your compiler automatically; a status bar item shows which one it picked and lets you override it.

FASM: Debug assembles the active file with an injected listing macro (your source is never modified) and launches it under gdb/lldb, with real breakpoints, stepping, and a live register view. fasm2 doesn't emit standard debug info by default, so source-line mapping comes from that listing instead — which also means there's no call-stack unwinding or typed variables; register and memory inspection via gdb's own expression evaluator ($eax, *(dword*)$esp, ...) is the right level of detail for raw assembly anyway. Currently fasm2/fasmg sources only.

Requirements

Install fasm2/fasmg (and/or classic fasm1) yourself and make sure it's on PATH, or point fasm2Studio.fasm2CompilerPath / fasm2Studio.fasm1CompilerPath at it in your settings.

To use the debugger:

Linux — gdb (already installed on most distros; otherwise apt install gdb, dnf install gdb, or pacman -S gdb).
macOS — Xcode Command Line Tools (xcode-select --install), which provides lldb.
Windows — a gdb build, most easily from MSYS2 (pacman -S mingw-w64-x86_64-gdb) or w64devkit. There's no built-in equivalent to gdb/lldb on Windows, so this is the one genuinely extra step compared to the other two platforms.

Settings

Setting	Description
`fasm2Studio.defaultDialect`	Dialect assumed when it can't be auto-detected from a file's contents.
`fasm2Studio.fasm2CompilerPath`	Path to fasm2/fasmg. Leave empty to auto-detect on PATH.
`fasm2Studio.fasm1CompilerPath`	Path to fasm1. Leave empty to auto-detect on PATH.
`fasm2Studio.gdbPath`	Path to gdb, used by `FASM: Debug`. Leave empty to use `gdb` from PATH.
`fasm2Studio.diagnosticsEnabled`	Compile in the background to show errors/warnings as you edit.
`fasm2Studio.diagnosticsDebounceMs`	How long to wait after you stop typing before re-running diagnostics.
`fasm2Studio.buildOutputPath`	Output path for Build/Run/Debug, relative to the source file's directory (e.g. `../bin/cc`) — keeps build output out of the source tree. Leave empty to build next to the source.

Source and issues

github.com/Lu4nScr1pt1ng/FASM-2-Studio — bug reports, feature requests, and contributions welcome; see CONTRIBUTING.md in the repository.

Licensing

This extension is MIT-licensed. flat assembler itself is a separate project with its own license, held by its author, Tomasz Grysztar; this extension doesn't redistribute it and just invokes whatever copy you have installed.