DDLess PHP Debug Engine

This is the PHP engine only. For the full debugging experience (desktop app, UI, AI Copilot, Task Runner), visit ddless.com

The PHP runtime engine that powers DDLess — a visual debugger for PHP applications.

This engine handles code instrumentation, breakpoint management, step-through execution, and variable inspection. It works with any PHP project (vanilla PHP, Laravel, Symfony, etc.) running on PHP 7.4+.

How It Works

DDLess uses AST-based analysis (via nikic/PHP-Parser) to understand your code structure. It injects step-check calls before each executable line, allowing the debugger to pause, inspect variables, and control execution flow — all without modifying your original files.

Core Components

File	Purpose
src/debug.php	Main engine — AST analysis, instrumentation, breakpoint handler, variable serialization
src/http_trigger.php	Entry point for HTTP debug sessions
src/method_trigger.php	Entry point for method-level debugging
src/task_trigger.php	Entry point for task/command debugging
src/cli_trigger.php	Entry point for CLI script debugging
src/frameworks/laravel/	Laravel-specific request handling, method execution, task runner
src/frameworks/symfony/	Symfony request handling, method execution, task runner
src/frameworks/codeigniter/	CodeIgniter 4 request handling, method execution, task runner
src/frameworks/tempest/	Tempest request handling, method execution, task runner
src/frameworks/wordpress/	WordPress request handling, method execution, task runner
src/frameworks/php/	Vanilla PHP request handling, method execution, task runner
src/vendor-internal/	Bundled PHP-Parser (no Composer required)

Key Functions

• ddless_analyze_code_ast() — Parses PHP source into AST and identifies instrumentable lines
• ddless_instrument_code_with_ast() — Injects debug hooks into source code
• ddless_step_check() — Called before every executable line, decides whether to pause
• ddless_handle_breakpoint() — Pauses execution, captures state, waits for debugger command
• ddless_normalize_value() — Serializes variables for display (handles objects, enums, DateTime, etc.)

Requirements

• PHP 7.4 or higher (tested up to 8.4)
• json extension (included by default)

Running Tests

php tests/run-all.php

Individual test files can also be run directly:

php tests/NormalizeValueTest.php
php tests/InstrumentCodeAstTest.php
php tests/HttpRequestTest.php

Test Matrix

Tests run automatically on every push and PR against PHP 7.4, 8.0, 8.1, 8.2, 8.3, and 8.4.

License

Source-available. You may read, audit, and report issues. Redistribution and derivative products are not permitted. See LICENSE for full terms.