12dPL Language Server
A professional language server for 12dPL with intelligent code completion and real-time validation.
This repository’s documentation is split into the following Markdown files:
README.md - General User Information and FeaturesCONTRIBUTING.md - Developer specific information.
Table of Contents
- Features
- Quick Start Guide
- Usage
- Configuration
- Dependencies
- License
- Contributing
- Contributors
✨ Features
Implemented
- Syntax Highlighting - Full 12dPL grammar support
- Code Completion - Builtins + local symbols + include-aware symbols
- Real-time Validation - ANTLR-based code parsing and error detection
- AST Parsing - Complete abstract syntax tree generation
- Function Documentation - Hover over builtins, local symbols, include symbols, and
#define macros
- Go to Definition - Works for local symbols and across included files (including
#define macros)
- Signature Help - Parameter info tooltip appears as you type, with active parameter highlighted and all overloads shown
- Rename All Symbols - Scope-aware rename across the current file (F2 or right-click > Rename Symbol)
- Formatting - Brace-based formatting with configurable bracket style, indent style, and line-length wrapping (supports format-on-save)
- Preprocessor Support -
#include/#define suggestions, include-path completion, macro completion, and macro expansion during validation
- Advanced Grammar Support - Arrays, Switch statements, Pass-by-reference, Macros
- Document Outline - Functions and global variables shown in the VS Code outline panel and breadcrumb bar
- Semantic Highlighting - Macro definitions and uppercase constants are highlighted distinctly
- Control Flow Validation - Detects unreachable code, missing
break in switch cases, and switch without default
- Assignment Type Validation - Reports type mismatches and lossy promotions in assignments
- Logical Condition Validation - Warns on non-boolean loop/condition expressions
- Array Size Validation - Flags unsized array declarations in function bodies
- Undeclared Symbol Detection - Flags calls to functions not declared locally, in headers, or in built-in prototypes
Coming Soon
- Document Highlights: highlights all matching symbols in a text document
- Find References: find all references to a symbol
- List Workspace Symbols: lists all project-wide symbols
What's New in v1.6.0
Pass-by-Reference Temporary Value Warnings ✨
- Passing a literal or temporary value to a
& (pass-by-reference) parameter now produces a warning, since the callee cannot write back to a temporary
Block-Scope Variable Leak Detection ✨
- Variables declared inside a block (
if, for, etc.) are no longer accessible outside that block; using them after scope ends is reported as an error
Preprocessor Defines from Headers ✨
#define macros from included header files are now collected and substituted before validation, eliminating false positives from macro-defined values in headers
Bug Fixes
- Macro
#define bodies now have comments stripped before substitution, so inline or trailing comments no longer corrupt the substituted value (v1.5.8)
for loop header variables (e.g. for(Integer i = 0; ...)) are no longer incorrectly flagged as re-declarations (v1.5.7)- Further fixes to preprocessor
#define collection and substitution from headers (v1.5.7)
- Switch statement formatting: cases with compound bodies are now indented correctly
🚀 Quick Start Guide
What's New
✨ Auto-Completion with 8000+ Library Functions
The language server provides intelligent auto-completion for all 12dPL library functions including:
- Mathematical functions (Sin, Cos, Tan, etc.)
- String operations
- File I/O
- Control flow
- And much more...
💡 Usage
Auto-Completion
- Open a
.4dm file
- Start typing a function name or variable (Can be user defined) (e.g., "Sin", "Print")
- Auto-complete suggestions appear
- Press
Ctrl+Space to manually trigger
Diagnostics - Error Checking
- Syntax errors appear with red squiggles
- View all errors in the Problems panel
- Navigate with F8 (next problem)
This extension provides a basic C/C++-style formatter (brace-based indentation) for .4dm files.
Format-on-save is disabled by default, if you wish to use this feature it can be enabled in the extensions settings.
This extension can invoke the 12dPL compiler and can compile the current file into a .4do in the same folder.
- Open a
.4dm file
- Click the Play button (
▶ 12dPL) in the VS Code status bar to compile immediately or run “12dPL: Compile Current File” from the Command Palette
- Check the Output panel: 12dPL Compiler
The Output also prints the detected cc4d compiler version, and the Play button tooltip shows it when available.
Compiler Flags (Checkboxes)
To compile with selectable flags, use the Gear button (⚙ 12dPL) in the status bar or run “12dPL: Compile Current File (Select Flags)”.
🔧 Configuration
There are a few available settings that are defined for the language server that can be used to customise the way the language server behaves. They are listed below with a description of their use.
- 12dpl.compiler.availableFlags
- List of cc4d compiler flags to show as checkboxes when compiling. Each entry may include arguments, e.g. '-log "build.log"' or '-codepage 1252'.
- 12dpl.compiler.path
- Path to the folder containing the cc4d.exe compiler. Example: C:\Program Files\12d\12dmodel\15.00\nt.x64\
- 12dpl.compiler.includePaths
- List of folders to prepend to the PATH environment variable before running the compiler (useful for include directories). Use platform paths; on Windows use semicolon-separated PATH semantics.
- 12dpl.compiler.defaultFlags
- Default cc4d flags to preselect in the compile checkbox picker. Last selection is remembered per-workspace.
- 12dpl.formatOnSave
- Auto-format 12dPL files when they are saved.
- 12dpl.indentSize
- Indent size (spaces) used by the 12dPL formatter.
- langServer.maxNumberOfProblems
- Controls the maximum number of problems produced by the server.
- langServer.trace.server
- Traces the communication between VS Code and the language server.
📦 Dependencies
Core
vscode-languageserver - LSP implementationvscode-languageserver-textdocument - Text document handlingantlr4 - Parser generation
Data
xml2js - XML parsing for prototypes
📄 License
MIT License - See LICENSE file for details
👥 Contributing
Contributions welcome! Please submit pull requests or issues.
👤 Contributors
Ben Olsen
Kamal Jarada
Thanks to everyone helping to improve the extension by reporting bugs and suggesting features:
