Merge pull request RustPython#2402 from RustPython/wasm-hooks

Add a way to inject modules to rustpython_wasm

Author: coolreader18

Cargo.lock

@@ -13,6 +13,7 @@ crate-type = ["cdylib", "rlib"]
 [features]
 default = ["freeze-stdlib"]
 freeze-stdlib = ["rustpython-vm/freeze-stdlib"]
+no-start-func = []
 
 [dependencies]
 rustpython-parser = { path = "../../parser" }
@@ -24,6 +25,7 @@ wasm-bindgen-futures = "0.4"
 serde-wasm-bindgen = "0.1"
 serde = "1.0"
 js-sys = "0.3"
+console_error_panic_hook = "0.1"
 # make parking_lot use wasm-bingden for instant
 parking_lot = { version = "0.11", features = ["wasm-bindgen"] }
 

wasm/lib/Cargo.toml

@@ -7,106 +7,131 @@ pub mod wasm_builtins;
 #[macro_use]
 extern crate rustpython_vm;
 
-use js_sys::{Object, Reflect, TypeError};
-use rustpython_vm::compile::Mode;
+pub(crate) use vm_class::weak_vm;
+
+use js_sys::{Reflect, WebAssembly::RuntimeError};
 use std::panic;
 use wasm_bindgen::prelude::*;
 
-pub use crate::convert::PyError;
-pub use crate::vm_class::*;
-
-const PY_EVAL_VM_ID: &str = "__py_eval_vm";
+pub use vm_class::add_init_func;
 
-fn panic_hook(info: &panic::PanicInfo) {
+/// Sets error info on the window object, and prints the backtrace to console
+pub fn panic_hook(info: &panic::PanicInfo) {
     // If something errors, just ignore it; we don't want to panic in the panic hook
-    use js_sys::WebAssembly::RuntimeError;
-    let window = match web_sys::window() {
-        Some(win) => win,
-        None => return,
+    let try_set_info = || {
+        let msg = &info.to_string();
+        let window = match web_sys::window() {
+            Some(win) => win,
+            None => return,
+        };
+        let _ = Reflect::set(&window, &"__RUSTPYTHON_ERROR_MSG".into(), &msg.into());
+        let error = RuntimeError::new(&msg);
+        let _ = Reflect::set(&window, &"__RUSTPYTHON_ERROR".into(), &error);
+        let stack = match Reflect::get(&error, &"stack".into()) {
+            Ok(stack) => stack,
+            Err(_) => return,
+        };
+        let _ = Reflect::set(&window, &"__RUSTPYTHON_ERROR_STACK".into(), &stack);
     };
-    let msg = &info.to_string();
-    let _ = Reflect::set(&window, &"__RUSTPYTHON_ERROR_MSG".into(), &msg.into());
-    let error = RuntimeError::new(&msg);
-    let _ = Reflect::set(&window, &"__RUSTPYTHON_ERROR".into(), &error);
-    let stack = match Reflect::get(&error, &"stack".into()) {
-        Ok(stack) => stack,
-        Err(_) => return,
-    };
-    let _ = Reflect::set(&window, &"__RUSTPYTHON_ERROR_STACK".into(), &stack);
+    try_set_info();
+    console_error_panic_hook::hook(info);
 }
 
+#[doc(hidden)]
+#[cfg(not(feature = "no-start-func"))]
 #[wasm_bindgen(start)]
-pub fn setup_console_error() {
+pub fn _setup_console_error() {
     std::panic::set_hook(Box::new(panic_hook));
 }
 
-fn run_py(source: &str, options: Option<Object>, mode: Mode) -> Result<JsValue, JsValue> {
-    let vm = VMStore::init(PY_EVAL_VM_ID.into(), Some(true));
-    let options = options.unwrap_or_else(Object::new);
-    let js_vars = {
-        let prop = Reflect::get(&options, &"vars".into())?;
-        if prop.is_undefined() {
-            None
-        } else if prop.is_object() {
-            Some(Object::from(prop))
-        } else {
-            return Err(TypeError::new("vars must be an object").into());
+pub mod eval {
+    use crate::vm_class::VMStore;
+    use js_sys::{Object, Reflect, TypeError};
+    use rustpython_vm::compile::Mode;
+    use wasm_bindgen::prelude::*;
+
+    const PY_EVAL_VM_ID: &str = "__py_eval_vm";
+
+    fn run_py(source: &str, options: Option<Object>, mode: Mode) -> Result<JsValue, JsValue> {
+        let vm = VMStore::init(PY_EVAL_VM_ID.into(), Some(true));
+        let options = options.unwrap_or_else(Object::new);
+        let js_vars = {
+            let prop = Reflect::get(&options, &"vars".into())?;
+            if prop.is_undefined() {
+                None
+            } else if prop.is_object() {
+                Some(Object::from(prop))
+            } else {
+                return Err(TypeError::new("vars must be an object").into());
+            }
+        };
+
+        vm.set_stdout(Reflect::get(&options, &"stdout".into())?)?;
+
+        if let Some(js_vars) = js_vars {
+            vm.add_to_scope("js_vars".into(), js_vars.into())?;
         }
-    };
+        vm.run(source, mode, None)
+    }
 
-    vm.set_stdout(Reflect::get(&options, &"stdout".into())?)?;
+    /// Evaluate Python code
+    ///
+    /// ```js
+    /// var result = pyEval(code, options?);
+    /// ```
+    ///
+    /// `code`: `string`: The Python code to run in eval mode
+    ///
+    /// `options`:
+    ///
+    /// -   `vars?`: `{ [key: string]: any }`: Variables passed to the VM that can be
+    ///     accessed in Python with the variable `js_vars`. Functions do work, and
+    ///     receive the Python kwargs as the `this` argument.
+    /// -   `stdout?`: `"console" | ((out: string) => void) | null`: A function to replace the
+    ///     native print native print function, and it will be `console.log` when giving
+    ///     `undefined` or "console", and it will be a dumb function when giving null.
+    #[wasm_bindgen(js_name = pyEval)]
+    pub fn eval_py(source: &str, options: Option<Object>) -> Result<JsValue, JsValue> {
+        run_py(source, options, Mode::Eval)
+    }
 
-    if let Some(js_vars) = js_vars {
-        vm.add_to_scope("js_vars".into(), js_vars.into())?;
+    /// Evaluate Python code
+    ///
+    /// ```js
+    /// pyExec(code, options?);
+    /// ```
+    ///
+    /// `code`: `string`: The Python code to run in exec mode
+    ///
+    /// `options`: The options are the same as eval mode
+    #[wasm_bindgen(js_name = pyExec)]
+    pub fn exec_py(source: &str, options: Option<Object>) -> Result<(), JsValue> {
+        run_py(source, options, Mode::Exec).map(drop)
     }
-    vm.run(source, mode, None)
-}
 
-/// Evaluate Python code
-///
-/// ```js
-/// var result = pyEval(code, options?);
-/// ```
-///
-/// `code`: `string`: The Python code to run in eval mode
-///
-/// `options`:
-///
-/// -   `vars?`: `{ [key: string]: any }`: Variables passed to the VM that can be
-///     accessed in Python with the variable `js_vars`. Functions do work, and
-///     receive the Python kwargs as the `this` argument.
-/// -   `stdout?`: `"console" | ((out: string) => void) | null`: A function to replace the
-///     native print native print function, and it will be `console.log` when giving
-///     `undefined` or "console", and it will be a dumb function when giving null.
-#[wasm_bindgen(js_name = pyEval)]
-pub fn eval_py(source: &str, options: Option<Object>) -> Result<JsValue, JsValue> {
-    run_py(source, options, Mode::Eval)
+    /// Evaluate Python code
+    ///
+    /// ```js
+    /// var result = pyExecSingle(code, options?);
+    /// ```
+    ///
+    /// `code`: `string`: The Python code to run in exec single mode
+    ///
+    /// `options`: The options are the same as eval mode
+    #[wasm_bindgen(js_name = pyExecSingle)]
+    pub fn exec_single_py(source: &str, options: Option<Object>) -> Result<JsValue, JsValue> {
+        run_py(source, options, Mode::Single)
+    }
 }
 
-/// Evaluate Python code
-///
-/// ```js
-/// pyExec(code, options?);
-/// ```
-///
-/// `code`: `string`: The Python code to run in exec mode
-///
-/// `options`: The options are the same as eval mode
-#[wasm_bindgen(js_name = pyExec)]
-pub fn exec_py(source: &str, options: Option<Object>) -> Result<(), JsValue> {
-    run_py(source, options, Mode::Exec).map(drop)
+/// A module containing all the wasm-bindgen exports that rustpython_wasm has
+/// Re-export as `pub use rustpython_wasm::exports::*;` in the root of your crate if you want your
+/// wasm module to mimic rustpython_wasm's API
+pub mod exports {
+    pub use crate::convert::PyError;
+    pub use crate::eval::{eval_py, exec_py, exec_single_py};
+    pub use crate::vm_class::{VMStore, WASMVirtualMachine};
 }
 
-/// Evaluate Python code
-///
-/// ```js
-/// var result = pyExecSingle(code, options?);
-/// ```
-///
-/// `code`: `string`: The Python code to run in exec single mode
-///
-/// `options`: The options are the same as eval mode
-#[wasm_bindgen(js_name = pyExecSingle)]
-pub fn exec_single_py(source: &str, options: Option<Object>) -> Result<JsValue, JsValue> {
-    run_py(source, options, Mode::Single)
-}
+#[doc(hidden)]
+pub use exports::*;

wasm/lib/src/lib.rs

@@ -40,6 +40,12 @@ impl StoredVirtualMachine {
                 setup_browser_module(vm);
             }
 
+            VM_INIT_FUNCS.with(|cell| {
+                for f in cell.borrow().iter() {
+                    f(vm)
+                }
+            });
+
             scope = Some(vm.new_scope_with_builtins());
 
             InitParameter::Internal
@@ -53,11 +59,18 @@ impl StoredVirtualMachine {
     }
 }
 
+/// Add a hook to add builtins or frozen modules to the RustPython VirtualMachine while it's
+/// initializing.
+pub fn add_init_func(f: fn(&mut VirtualMachine)) {
+    VM_INIT_FUNCS.with(|cell| cell.borrow_mut().push(f))
+}
+
 // It's fine that it's thread local, since WASM doesn't even have threads yet. thread_local!
 // probably gets compiled down to a normal-ish static varible, like Atomic* types do:
 // https://rustwasm.github.io/2018/10/24/multithreading-rust-and-wasm.html#atomic-instructions
 thread_local! {
     static STORED_VMS: RefCell<HashMap<String, Rc<StoredVirtualMachine>>> = RefCell::default();
+    static VM_INIT_FUNCS: RefCell<Vec<fn(&mut VirtualMachine)>> = RefCell::default();
 }
 
 pub fn get_vm_id(vm: &VirtualMachine) -> &str {