feat(hotload): Hotloading implementation

Author: kakserpom

Cargo.toml

@@ -61,7 +61,7 @@ runtime = ["ext-php-rs-bindgen/runtime"]
 static = ["ext-php-rs-bindgen/static"]
 
 [workspace]
-members = ["crates/macros", "crates/cli", "crates/php-build", "tests"]
+members = ["crates/macros", "crates/cli", "crates/php-build", "crates/hotload", "tests"]
 
 [package.metadata.docs.rs]
 rustdoc-args = ["--cfg", "docs"]

crates/hotload/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "ext-php-rs-hotload"
+description = "Hot-load Rust code into PHP at runtime"
+version = "0.1.0"
+edition = "2021"
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/extphprs/ext-php-rs"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+ext-php-rs = { path = "../.." }
+libloading = "0.8"
+sha2 = "0.10"
+hex = "0.4"
+parking_lot = "0.12"
+tree-sitter = "0.23"
+tree-sitter-rust = "0.23"
+fs2 = "0.4"

crates/hotload/src/abi.rs

@@ -0,0 +1,37 @@
+//! Hotload ABI - shared interface between host and loaded modules
+//!
+//! Modules must export these symbols:
+//! - `hotload_info() -> *const PluginInfo`
+//! - `hotload_init()`
+
+use std::ffi::c_char;
+
+/// Plugin metadata
+#[repr(C)]
+pub struct PluginInfo {
+    /// Plugin name (null-terminated)
+    pub name: *const c_char,
+    /// Plugin version (null-terminated)
+    pub version: *const c_char,
+    /// Number of functions exported
+    pub num_functions: u32,
+    /// Array of function descriptors
+    pub functions: *const FunctionInfo,
+}
+
+/// Function metadata (just the name for cleanup purposes)
+#[repr(C)]
+pub struct FunctionInfo {
+    /// Function name as it appears in PHP (null-terminated)
+    pub name: *const c_char,
+}
+
+/// Type for the plugin info function
+pub type PluginInfoFn = unsafe extern "C" fn() -> *const PluginInfo;
+
+/// Type for the plugin init function (called after loading)
+pub type PluginInitFn = unsafe extern "C" fn();
+
+/// ABI version for compatibility checking
+#[allow(dead_code)]
+pub const ABI_VERSION: u32 = 1;