FreeBASIC Language

FreeBASIC support for Visual Studio Code, aligned with FreeBASIC 1.20.3.

The extension handles .bas and .bi files and combines source-backed syntax data with fast, conservative editor analysis. It does not require a separate language-server process.

Language support

• TextMate highlighting for declarations, control flow, types, operators, compiler defines, runtime functions, graphics APIs, TCP forms, and sfxlib command families
• declaration-name scopes for procedures, aggregates, namespaces, and constants
• FreeBASIC comments, block comments, number formats, string forms, word selection, auto-closing pairs, and block indentation
• snippets for common language structures, types, properties, graphics, input, files, networking, threads, serial ports, and current audio APIs
• hierarchical Outline and breadcrumb symbols for namespaces, types, enums, procedures, fields, parameters, and local declarations
• workspace symbol search across .bas and .bi files
• completion for user declarations and the audited built-in language surface
• hover, go to definition, find references, document highlights, and conservative workspace rename
• signature help for procedures and macros declared in the workspace
• folding for language blocks, preprocessor blocks, and ' #region or REM #region comment markers
• clickable local and configured #include paths

The workspace index is cached and updated as files change. Rename is offered only when the selected spelling has one unambiguous indexed declaration. The analyzer deliberately avoids claiming compiler-grade overload or type resolution.

Compiler diagnostics

Saved .bas modules can be checked by the real FreeBASIC compiler. The extension runs fbc in compile-only mode, writes the temporary object into an isolated temporary directory, and maps errors and warnings back to .bas and included .bi files.

Diagnostics run on save by default. They can also be run with FreeBASIC: Check Current Module from the Command Palette or the editor title menu. Compiler execution is disabled in untrusted workspaces and for virtual files.

Useful settings:

• freebasic.compiler.path: compiler path or command name, default fbc
• freebasic.compiler.arguments: additional arguments passed before the managed compile-only arguments
• freebasic.diagnostics.run: onSave or off
• freebasic.diagnostics.maxErrors: maximum compiler errors per check
• freebasic.diagnostics.timeoutMs: compiler process time limit
• freebasic.includePaths: extra directories for clickable includes; ${workspaceFolder} is supported
• freebasic.index.exclude: files excluded from workspace analysis
• freebasic.index.maxFiles: workspace analysis file limit
• freebasic.index.maxCompletionResults: workspace declarations added to one completion request
• freebasic.index.maxSymbolResults: workspace symbol result limit

Use FreeBASIC: Show Compiler Output to inspect the compiler's complete captured output. Use FreeBASIC: Rebuild Workspace Index after generated files or workspace configuration changes that VS Code did not report individually.

FreeBASIC 1.20.3 coverage

The reviewable grammar source is checked against the compiler and bundled headers that define the public surface:

• src/compiler/symb-keyword.bas
• src/compiler/symb-define.bas
• src/compiler/pp.bas
• src/compiler/rtl-*.bas
• src/compiler/parser-*.bas
• src/compiler/fb.bi, src/compiler/symb.bas, and src/compiler/fbc.bas
• inc/builtin.bi
• inc/fbgfx.bi and inc/fbgfx3.bi
• inc/fbcom.bi
• inc/sfxlib_effects.bi and inc/sfxlib_raw.bi

The audit covers 253 compiler keywords, all 25 current preprocessor directives, 122 public RTL registrations, 97 compiler defines, the parser-defined sound command families, and selected bundled APIs and constants. The configured source checkout currently identifies itself as 1.20.4, so the audit also verifies that every inspected public-language path is unchanged from Git tag v1.20.3.

This includes current touch and controller APIs, gfxlib3 surfaces, builtin.bi, portable fbcom, the opt-in sfxlib effects and raw-output helpers, and the exact MUSIC, SFX, MIDI, DEVICE, and CAPTURE command families. Obsolete forms such as AUDIO, STREAM, and MUSIC CURRENT are not presented as current syntax.

Building and testing

The grammar generator and audit use Node.js and work through npm:

npm run build:grammar
npm run audit:grammar
npm test

The audit discovers /home/jkfirth/fbc from this repository layout. For another checkout, set FREEBASIC_ROOT or pass --freebasic-root to tools/audit-freebasic-coverage.js.

VSIX packaging does not require vsce. The default command selects the Bash builder on Linux and the PowerShell builder on Windows:

npm run package:vsix

The Linux builder requires Node.js plus the standard zip and unzip commands. It validates every expected archive entry before publishing the finished file.

The platform builders can also be invoked directly:

./tools/build-vsix.sh

powershell -ExecutionPolicy Bypass -File .\tools\build-vsix.ps1

Both builders produce dist/fb-vscode-language-1.20.3.vsix. To test the package on Linux without changing the normal extension profile:

code --transient --extensions-dir ./.tmp-code-extensions --install-extension ./dist/fb-vscode-language-1.20.3.vsix --force

The equivalent PowerShell command is:

code --transient --extensions-dir .\.tmp-code-extensions --install-extension .\dist\fb-vscode-language-1.20.3.vsix --force

The full test command rebuilds the checked-in grammar, audits the FreeBASIC source surface, validates package assets, and runs parser, index, diagnostic, and string-token regression tests.