Crate ext_php_rs

ext-php-rs

Bindings and abstractions for the Zend API to build PHP extensions natively in Rust.

Example

Export a simple function function hello_world(string $name): string to PHP:

use ext_php_rs::prelude::*;

/// Gives you a nice greeting!
/// 
/// @param string $name Your name.
/// 
/// @return string Nice greeting!
#[php_function]
pub fn hello_world(name: String) -> String {
    format!("Hello, {}!", name)
}

// Required to register the extension with PHP.
#[php_module]
pub fn module(module: ModuleBuilder) -> ModuleBuilder {
    module
}

Use cargo-php to build IDE stubs and install the extension:

$ cargo install cargo-php
  Installing cargo-php v0.1.0
$ cargo php stubs --stdout
  Compiling example-ext v0.1.0
  Finished dev [unoptimized + debuginfo] target(s) in 3.57s
<?php

// Stubs for example-ext

/**
 * Gives you a nice greeting!
 *
 * @param string $name Your name.
 *
 * @return string Nice greeting!
 */
function hello_world(string $name): string {}
$ cargo php install --release
  Compiling example-ext v0.1.0
  Finished release [optimized] target(s) in 1.68s
Are you sure you want to install the extension `example-ext`? yes
$ php -m
[PHP Modules]
// ...
example-ext
// ...

Calling the function from PHP:

var_dump(hello_world("David")); // string(13) "Hello, David!"

For more examples read the library guide.

Features

• Easy to use: The built-in macros can abstract away the need to interact with the Zend API, such as Rust-type function parameter abstracting away interacting with Zend values.
• Lightweight: You don’t have to use the built-in helper macros. It’s possible to write your own glue code around your own functions.
• Extensible: Implement IntoZval and FromZval for your own custom types, allowing the type to be used as function parameters and return types.

Goals

Our main goal is to make extension development easier.

• Writing extensions in C can be tedious, and with the Zend APIs limited documentation can be intimidating.
• Rust’s modern language features and feature-full standard library are big improvements on C.
• Abstracting away the raw Zend APIs allows extensions to be developed faster and with more confidence.
• Abstractions also allow us to support future (and potentially past) versions of PHP without significant changes to extension code.

Documentation

The library guide can be read here.

The project is documented in-line, so viewing the cargo documentation is the best resource at the moment. This can be viewed at docs.rs.

Requirements

• PHP 8.0 or later
  • No support is planned for lower versions.
• Linux or Darwin-based OS
• Rust - no idea which version
• Clang 3.9 or greater

See the following links for the dependency crate requirements:

• cc
• bindgen

Cargo Features

All features are disabled by default.

• closure - Enables the ability to return Rust closures to PHP. Creates a new class type, RustClosure.
• anyhow - Implements Into<PhpException> for anyhow::Error, allowing you to return anyhow results from PHP functions. Supports anyhow v1.x.

Usage

This project only works for PHP >= 8.0 (for now). Due to the fact that the PHP extension system relies heavily on C macros (which cannot be exported to Rust easily), structs have to be hard coded in.

Check out one of the example projects:

• anonaddy-sequoia - Sequoia encryption PHP extension.
• opus-php - Audio encoder for the Opus codec in PHP.

Contributions

Contributions are very much welcome. I am a novice Rust developer and any suggestions are wanted and welcome. Feel free to file issues and PRs through Github.

Contributions welcome include:

• Documentation expansion (examples in particular!)
• Safety reviews (especially if you have experience with Rust and the Zend API).
• Bug fixes and features.
• Feature requests.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Resources

• PHP Internals Book

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE_APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE_MIT or http://opensource.org/licenses/MIT)

at your option.

Modules

alloc

Functions relating to the Zend Memory Manager, used to allocate request-bound memory.

args

Builder and objects relating to function and method arguments.

binary

Provides implementations for converting to and from Zend binary strings, commonly returned from functions such as pack and unpack.

boxed

A pointer type for heap allocation using the Zend memory manager.

builders

Structures that are used to construct other, more complicated types. Generally zero-cost abstractions.

class

Types and traits used for registering classes with PHP.

closureclosure

Types and functions used for exporting Rust closures to PHP.

constant

Types and traits for registering constants in PHP.

convert

Traits used to convert between Zend/PHP and Rust types.

describe

Types used to describe downstream extensions. Used by the cargo-php CLI application to generate PHP stub files used by IDEs.

error

Error and result types returned from the library functions.

exception

Types and functions used for throwing exceptions from Rust to PHP.

ffi

Raw FFI bindings to the Zend API.

flags

Flags and enums used in PHP and the Zend engine.

macros

Macros for interacting with PHP, mainly when the function takes variadic arguments. Unforutunately, this is the best way to handle these. Note that most of these will introduce unsafe into your code base.

prelude

A module typically glob-imported containing the typically required macros and imports.

props

Types and traits for adding properties to PHP classes registered from Rust.

rc

Traits and types for interacting with reference counted PHP types.

types

Types defined by the Zend engine used in PHP.

zend

Types used to interact with the Zend engine.

Macros

call_user_func

Attempts to call a given PHP callable.

class_derives

Implements a set of traits required to convert types that implement RegisteredClass to and from ZendObjects and Zvals. Generally, this macro should not be called directly, as it is called on any type that uses the php_class macro.

info_table_end

Ends the PHP extension information table. Must be run after all rows have been inserted into the table.

info_table_header

Sets the header for the PHP extension information table. Takes as many string arguments as required.

info_table_row

Adds a row to the PHP extension information table. Takes as many string arguments as required.

info_table_start

Starts the PHP extension information table displayed when running phpinfo(); Must be run before rows are inserted into the table.

parse_args

Parses a given list of arguments using the ArgParser class.

throw

Throws an exception and returns from the current function.

Constants

VERSION

ext-php-rs version.

Attribute Macros

php_class

Annotates a struct that will be exported to PHP as a class.

php_const

Attribute used to annotate constants to be exported to PHP.

php_extern

Attribute used to annotate extern blocks which are deemed as PHP functions.

php_function

Attribute used to annotate a function as a PHP function.

php_impl

Annotates a structs impl block, declaring that all methods and constants declared inside the impl block will be declared as PHP methods and constants.

php_module

Annotates a function that will be used by PHP to retrieve information about the module.

php_startup

Annotates a function that will be called by PHP when the module starts up. Generally used to register classes and constants.

Derive Macros

ZvalConvert

Derives the traits required to convert a struct or enum to and from a Zval. Both FromZval and IntoZval are implemented on types which use this macro.