Analyzing PHP Keyword Conflicts with the Rust‑Based php‑syntax‑analyzer

This library is a Rust‑implemented command‑line tool designed to analyze PHP packages and assess the impact of turning new identifiers (e.g., let, using) into reserved keywords. It was created for the PHP RFC "opt‑in block scoping" to help developers detect breaking changes before they are introduced.

Key Features

Targeted analysis : Specify one or more keywords to check, with repeatable entries.

Package download & extraction : Automatically fetch and unpack the top N most popular packages from Packagist (default 100‑500, configurable).

Conflict detection : Scan source files for potential conflicts where the chosen keywords are used as variable or function names.

Result aggregation : Report safety for each keyword (no conflicts or number of conflicts) and optionally display detailed issues.

Optimization options : Skip the download step to analyze already‑downloaded packages or limit analysis to a specific directory.

Installation

The tool is built with Cargo and does not require publishing a crate:

git clone https://github.com/azjezz/php-syntax-analyzer.git
cd php-syntax-analyzer
cargo build --release

After building, the binary is located at target/release/php-syntax-analyzer.

Basic Usage

Run the binary directly or via cargo run. The core command syntax is: php-syntax-analyzer [options] Analyze a single keyword (e.g., let) across the first 10,000 packages: cargo run --release -- -k let --max 10000 Analyze multiple keywords while skipping the download step (assuming packages are already present):

cargo run --release -- -k let -k using -k scope -k block -k with --skip-download

Important Options

-k, --keyword <KEYWORD>

: Specify a target keyword (repeatable). --min <MIN>: Minimum package index (default 100). --max <MAX>: Maximum package index (default 500). -d, --directory <DIR>: Directory for downloaded packages (default ./downloads). --skip-download: Skip downloading and analyze existing source code. --display: Show detailed conflict information during analysis.

Notes & Limitations

RFC relevance : Tailored for the opt‑in block scoping RFC; for example, let shows no conflicts, while with reports 111 conflicts that could break code.

Limitations : The analysis may emit warnings (e.g., package extraction failures) and only covers popular Packagist packages, not the entire PHP ecosystem.

Current status : The repository has no formal release; developers should build the binary manually.

RFC reference: https://wiki.php.net/rfc/optin_block_scoping