baron-vsc

Visual Studio Code language support for the Baron 6502 assembler — the spiritual successor to BeebAsm (and to beeb-vsc, which inspired this extension).

Features

Syntax highlighting

A TextMate grammar covering the whole Baron language: mnemonics (NMOS and 65C02), directives, labels, scopes, strings (with "" escapes), &/$ hex and % binary numbers, lists, ranges (.. / ..<), operators, built-in functions, and both ; and \ comments. Inline BASIC … ENDBASIC blocks are highlighted as BBC BASIC with the ROM tokeniser's real matching rules (generated from baron's basic.c table): keywords match in ROM table order without needing whitespace (FORX=1TO10 is FOR, X, TO), the conditional-flag veto applies (COUNT is a keyword, COUNTER a variable), P.-style abbreviations resolve to the right keyword, PROC/FN names, * commands, REM/DATA raw tails, uppercase-only & hex, and line numbers.

CMOS-aware opcode colouring

The parser tracks SECTION nesting and evaluates the cmos attribute (inherited by nested sections, exactly as baron does). 65C02-only instructions — the extra mnemonics, and the CMOS-only addressing modes such as LDA (zp), BIT #, BIT zp,X, INC A and JMP (abs,X) — are coloured as ordinary opcodes inside a cmos = TRUE section, and as invalid (red) in plain NMOS context, via semantic tokens.

Navigation and editing

A TypeScript parser mirroring baron's own (lexer.c / assemble.c / expression.c are the reference) understands symbols, labels, named and anonymous scopes, local labels (.@, @-, @+), macros (with overloads), functions, sections, INCLUDEs, and full expressions including multi-line lists, ranges and subscripts. On top of it:

• Go to definition (F12) — works on dotted paths (wipe.nonzero), macro calls, INCSECTION names, @-/@+, and INCLUDE/INCBIN file names.
• Find all references (Shift+F12).
• Hover — the defining line, its scope, doc comments above it, and the evaluated value of constant symbols (decimal and hex).
• Completion — keywords, mnemonics, macros at statement start; visible symbols, functions, built-ins in expressions; members after scope.; section names after INCSECTION; attribute names on SECTION lines.
• Outline / breadcrumbs — sections, scopes, labels, macros, functions, symbols.

Scoping follows baron precisely: labels bind in the enclosing scope, a label immediately before { names the scope (one separator allowed between), anonymous scopes are private, IF does not scope, FOR bodies and macro/function bodies do.

Building

• Baron: Assemble (Ctrl+Alt+B) — runs baron on the configured root files with the configured switches. Errors and warnings land in the Problems panel and the Baron output channel.
• Baron: Assemble with Switches... (Ctrl+Alt+Shift+B) — prompts for the switches first (remembered per workspace).
• Baron: Set Root Source Files from Active Editor — quick way to set baron.sourceFiles.
• A $baron problem matcher is contributed for custom tasks.

Setup

In your workspace .vscode/settings.json:

{
  "baron.executablePath": "/path/to/baron",
  "baron.sourceFiles": ["boot.6502", "loader.6502", "demo.6502"],
  "baron.buildArgs": ["--opt", "3", "--title", "STARGLOBE", "-o", "demo.ssd", "-v"]
}

baron.sourceFiles is the root set — the files you would pass on the baron command line. Each assembles independently (its own symbol table), and together with their INCLUDE graphs they define what go-to-definition can see. With no root files configured, the active editor's file is used.

baron.diagnosticsOnSave (default off) reruns baron on every save. Note baron has no check-only mode: a successful save-triggered run writes its outputs just like a build.

Development

npm install
npm run build     # bundle to dist/extension.js
npm test          # core parser tests (no VS Code needed)
npm run package   # build the .vsix

Press F5 in VS Code to launch an Extension Development Host. JOURNAL.md records the verified-against-baron-source behaviour notes; when the language and the docs disagree, the baron C source is the authority.