668 lines
26 KiB
Rust
668 lines
26 KiB
Rust
use std::any::{Any, TypeId};
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use std::collections::HashMap;
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use std::error::Error as StdError;
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use std::fmt::Write;
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use std::os::raw::{c_int, c_void};
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use std::panic::{catch_unwind, resume_unwind, AssertUnwindSafe};
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use std::sync::{Arc, Mutex};
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use std::{mem, ptr, slice};
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use once_cell::sync::Lazy;
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use crate::error::{Error, Result};
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use crate::ffi;
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static METATABLE_CACHE: Lazy<Mutex<HashMap<TypeId, u8>>> = Lazy::new(|| {
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// The capacity must(!) be greater than number of stored keys
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Mutex::new(HashMap::with_capacity(32))
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});
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// Checks that Lua has enough free stack space for future stack operations. On failure, this will
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// panic with an internal error message.
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pub unsafe fn assert_stack(state: *mut ffi::lua_State, amount: c_int) {
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// TODO: This should only be triggered when there is a logic error in `mlua`. In the future,
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// when there is a way to be confident about stack safety and test it, this could be enabled
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// only when `cfg!(debug_assertions)` is true.
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mlua_assert!(
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ffi::lua_checkstack(state, amount) != 0,
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"out of stack space"
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);
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}
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// Checks that Lua has enough free stack space and returns `Error::StackError` on failure.
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pub unsafe fn check_stack(state: *mut ffi::lua_State, amount: c_int) -> Result<()> {
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if ffi::lua_checkstack(state, amount) == 0 {
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Err(Error::StackError)
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} else {
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Ok(())
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}
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}
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pub struct StackGuard {
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state: *mut ffi::lua_State,
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top: c_int,
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extra: c_int,
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}
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impl StackGuard {
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// Creates a StackGuard instance with wa record of the stack size, and on Drop will check the
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// stack size and drop any extra elements. If the stack size at the end is *smaller* than at
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// the beginning, this is considered a fatal logic error and will result in a panic.
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pub unsafe fn new(state: *mut ffi::lua_State) -> StackGuard {
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StackGuard {
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state,
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top: ffi::lua_gettop(state),
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extra: 0,
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}
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}
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// Similar to `new`, but checks and keeps `extra` elements from top of the stack on Drop.
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pub unsafe fn new_extra(state: *mut ffi::lua_State, extra: c_int) -> StackGuard {
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StackGuard {
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state,
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top: ffi::lua_gettop(state),
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extra,
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}
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}
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}
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impl Drop for StackGuard {
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fn drop(&mut self) {
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unsafe {
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let top = ffi::lua_gettop(self.state);
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if top < self.top + self.extra {
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mlua_panic!("{} too many stack values popped", self.top - top)
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}
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if top > self.top + self.extra {
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if self.extra > 0 {
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ffi::lua_rotate(self.state, self.top + 1, self.extra);
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}
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ffi::lua_settop(self.state, self.top + self.extra);
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}
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}
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}
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}
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// Call a function that calls into the Lua API and may trigger a Lua error (longjmp) in a safe way.
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// Wraps the inner function in a call to `lua_pcall`, so the inner function only has access to a
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// limited lua stack. `nargs` is the same as the the parameter to `lua_pcall`, and `nresults` is
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// always LUA_MULTRET. Internally uses 2 extra stack spaces, and does not call checkstack.
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// Provided function must *never* panic.
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pub unsafe fn protect_lua(
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state: *mut ffi::lua_State,
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nargs: c_int,
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f: unsafe extern "C" fn(*mut ffi::lua_State) -> c_int, // Must be "C-unwind" after stabilizing
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) -> Result<()> {
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let stack_start = ffi::lua_gettop(state) - nargs;
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ffi::lua_pushcfunction(state, ffi::safe::error_traceback);
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ffi::lua_pushcfunction(state, f);
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if nargs > 0 {
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ffi::lua_rotate(state, stack_start + 1, 2);
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}
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let ret = ffi::lua_pcall(state, nargs, ffi::LUA_MULTRET, stack_start + 1);
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ffi::lua_remove(state, stack_start + 1);
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if ret == ffi::LUA_OK {
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Ok(())
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} else {
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Err(pop_error(state, ret))
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}
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}
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// Pops an error off of the stack and returns it. The specific behavior depends on the type of the
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// error at the top of the stack:
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// 1) If the error is actually a WrappedPanic, this will continue the panic.
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// 2) If the error on the top of the stack is actually a WrappedError, just returns it.
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// 3) Otherwise, interprets the error as the appropriate lua error.
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// Uses 2 stack spaces, does not call checkstack.
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pub unsafe fn pop_error(state: *mut ffi::lua_State, err_code: c_int) -> Error {
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mlua_debug_assert!(
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err_code != ffi::LUA_OK && err_code != ffi::LUA_YIELD,
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"pop_error called with non-error return code"
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);
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if let Some(err) = get_wrapped_error(state, -1).as_ref() {
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ffi::lua_pop(state, 1);
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err.clone()
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} else if let Some(panic) = get_gc_userdata::<WrappedPanic>(state, -1).as_mut() {
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if let Some(p) = (*panic).0.take() {
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resume_unwind(p);
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} else {
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Error::PreviouslyResumedPanic
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}
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} else {
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let err_string = to_string(state, -1);
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ffi::lua_pop(state, 1);
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match err_code {
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ffi::LUA_ERRRUN => Error::RuntimeError(err_string),
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ffi::LUA_ERRSYNTAX => {
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Error::SyntaxError {
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// This seems terrible, but as far as I can tell, this is exactly what the
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// stock Lua REPL does.
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incomplete_input: err_string.ends_with("<eof>")
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|| err_string.ends_with("'<eof>'"),
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message: err_string,
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}
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}
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ffi::LUA_ERRERR => {
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// This error is raised when the error handler raises an error too many times
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// recursively, and continuing to trigger the error handler would cause a stack
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// overflow. It is not very useful to differentiate between this and "ordinary"
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// runtime errors, so we handle them the same way.
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Error::RuntimeError(err_string)
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}
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ffi::LUA_ERRMEM => Error::MemoryError(err_string),
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#[cfg(any(feature = "lua53", feature = "lua52"))]
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ffi::LUA_ERRGCMM => Error::GarbageCollectorError(err_string),
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_ => mlua_panic!("unrecognized lua error code"),
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}
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}
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}
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// Internally uses 3 stack spaces, does not call checkstack.
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pub unsafe fn push_userdata<T>(state: *mut ffi::lua_State, t: T) -> Result<()> {
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let ud = ffi::safe::lua_newuserdata(state, mem::size_of::<T>())? as *mut T;
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ptr::write(ud, t);
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Ok(())
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}
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pub unsafe fn get_userdata<T>(state: *mut ffi::lua_State, index: c_int) -> *mut T {
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let ud = ffi::lua_touserdata(state, index) as *mut T;
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mlua_debug_assert!(!ud.is_null(), "userdata pointer is null");
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ud
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}
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// Pops the userdata off of the top of the stack and returns it to rust, invalidating the lua
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// userdata and gives it the special "destructed" userdata metatable. Userdata must not have been
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// previously invalidated, and this method does not check for this.
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// Uses 1 extra stack space and does not call checkstack.
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pub unsafe fn take_userdata<T>(state: *mut ffi::lua_State) -> T {
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// We set the metatable of userdata on __gc to a special table with no __gc method and with
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// metamethods that trigger an error on access. We do this so that it will not be double
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// dropped, and also so that it cannot be used or identified as any particular userdata type
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// after the first call to __gc.
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get_destructed_userdata_metatable(state);
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ffi::lua_setmetatable(state, -2);
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let ud = get_userdata(state, -1);
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ffi::lua_pop(state, 1);
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ptr::read(ud)
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}
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// Pushes the userdata and attaches a metatable with __gc method.
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// Internally uses 3 stack spaces, does not call checkstack.
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pub unsafe fn push_gc_userdata<T: Any>(state: *mut ffi::lua_State, t: T) -> Result<()> {
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push_userdata(state, t)?;
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get_gc_metatable_for::<T>(state);
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ffi::lua_setmetatable(state, -2);
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Ok(())
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}
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// Uses 2 stack spaces, does not call checkstack
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pub unsafe fn get_gc_userdata<T: Any>(state: *mut ffi::lua_State, index: c_int) -> *mut T {
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let ud = ffi::lua_touserdata(state, index) as *mut T;
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if ud.is_null() || ffi::lua_getmetatable(state, index) == 0 {
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return ptr::null_mut();
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}
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get_gc_metatable_for::<T>(state);
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let res = ffi::lua_rawequal(state, -1, -2);
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ffi::lua_pop(state, 2);
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if res == 0 {
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return ptr::null_mut();
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}
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ud
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}
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// Populates the given table with the appropriate members to be a userdata metatable for the given type.
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// This function takes the given table at the `metatable` index, and adds an appropriate `__gc` member
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// to it for the given type and a `__metatable` entry to protect the table from script access.
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// The function also, if given a `field_getters` or `methods` tables, will create an `__index` metamethod
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// (capturing previous one) to lookup in `field_getters` first, then `methods` and falling back to the
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// captured `__index` if no matches found.
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// The same is also applicable for `__newindex` metamethod and `field_setters` table.
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// Internally uses 9 stack spaces and does not call checkstack.
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pub unsafe fn init_userdata_metatable<T>(
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state: *mut ffi::lua_State,
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metatable: c_int,
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field_getters: Option<c_int>,
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field_setters: Option<c_int>,
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methods: Option<c_int>,
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) -> Result<()> {
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ffi::lua_pushvalue(state, metatable);
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if field_getters.is_some() || methods.is_some() {
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ffi::safe::lua_pushstring(state, "__index")?;
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ffi::lua_pushvalue(state, -1);
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let index_type = ffi::lua_rawget(state, -3);
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match index_type {
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ffi::LUA_TNIL | ffi::LUA_TTABLE | ffi::LUA_TFUNCTION => {
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for &idx in &[field_getters, methods] {
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if let Some(idx) = idx {
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ffi::lua_pushvalue(state, idx);
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} else {
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ffi::lua_pushnil(state);
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}
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}
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ffi::safe::lua_pushcclosure(state, ffi::safe::meta_index_impl, 3)?;
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}
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_ => mlua_panic!("improper __index type {}", index_type),
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}
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ffi::safe::lua_rawset(state, -3)?;
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}
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if let Some(field_setters) = field_setters {
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ffi::safe::lua_pushstring(state, "__newindex")?;
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ffi::lua_pushvalue(state, -1);
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let newindex_type = ffi::lua_rawget(state, -3);
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match newindex_type {
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ffi::LUA_TNIL | ffi::LUA_TTABLE | ffi::LUA_TFUNCTION => {
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ffi::lua_pushvalue(state, field_setters);
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ffi::safe::lua_pushcclosure(state, ffi::safe::meta_newindex_impl, 2)?;
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}
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_ => mlua_panic!("improper __newindex type {}", newindex_type),
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}
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ffi::safe::lua_rawset(state, -3)?;
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}
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ffi::safe::lua_pushrclosure(state, userdata_destructor::<T>, 0)?;
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ffi::safe::lua_rawsetfield(state, -2, "__gc")?;
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ffi::lua_pushboolean(state, 0);
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ffi::safe::lua_rawsetfield(state, -2, "__metatable")?;
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ffi::lua_pop(state, 1);
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Ok(())
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}
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pub unsafe extern "C" fn userdata_destructor<T>(state: *mut ffi::lua_State) -> c_int {
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callback_error(state, |_| {
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check_stack(state, 1)?;
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take_userdata::<T>(state);
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Ok(0)
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})
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}
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// In the context of a lua callback, this will call the given function and if the given function
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// returns an error, *or if the given function panics*, this will result in a call to lua_error (a
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// longjmp) by a C shim. The error or panic is wrapped in such a way that when calling pop_error back
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// on the rust side, it will resume the panic (or when popping a panic value from the stack).
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//
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// This function assumes the structure of the stack at the beginning of a callback, that the only
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// elements on the stack are the arguments to the callback.
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//
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// This function uses some of the bottom of the stack for error handling, the given callback will be
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// given the number of arguments available as an argument, and should return the number of returns
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// as normal, but cannot assume that the arguments available start at 1.
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pub unsafe fn callback_error<F>(state: *mut ffi::lua_State, f: F) -> c_int
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where
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F: FnOnce(c_int) -> Result<c_int>,
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{
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let nargs = ffi::lua_gettop(state) - 1;
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match catch_unwind(AssertUnwindSafe(|| f(nargs))) {
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Ok(Ok(r)) => {
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ffi::lua_remove(state, 1);
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r
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}
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Ok(Err(err)) => {
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ffi::lua_settop(state, 1);
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let error_ud = ffi::lua_touserdata(state, 1);
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ptr::write(error_ud as *mut WrappedError, WrappedError(err, None));
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get_gc_metatable_for::<WrappedError>(state);
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ffi::lua_setmetatable(state, -2);
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-1
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}
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Err(p) => {
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ffi::lua_settop(state, 1);
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let error_ud = ffi::lua_touserdata(state, 1);
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ptr::write(error_ud as *mut WrappedPanic, WrappedPanic(Some(p)));
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get_gc_metatable_for::<WrappedPanic>(state);
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ffi::lua_setmetatable(state, -2);
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-2
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}
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}
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}
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// A part of the C shim for errors handling.
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// Receives indexes of error and traceback (optional) in the stack.
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// Depending on `convert_to_callback_error` flag attaches traceback to the error or
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// converts error into a `CallbackError` (using previously attached traceback).
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#[no_mangle]
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pub unsafe extern "C" fn wrapped_error_traceback(
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state: *mut ffi::lua_State,
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error_idx: c_int,
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traceback_idx: c_int,
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convert_to_callback_error: c_int,
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) {
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let wrapped_error = mlua_expect!(
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get_gc_userdata::<WrappedError>(state, error_idx).as_mut(),
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"cannot get <WrappedError>"
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);
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if convert_to_callback_error != 0 {
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let traceback = wrapped_error
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.1
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.take()
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.unwrap_or_else(|| "<not enough stack space for traceback>".into());
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let cause = Arc::new(wrapped_error.0.clone());
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wrapped_error.0 = Error::CallbackError { traceback, cause };
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} else {
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wrapped_error.1 = Some(to_string(state, traceback_idx));
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}
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}
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// Returns Lua main thread for Lua >= 5.2 or checks that the passed thread is main for Lua 5.1.
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// Does not call lua_checkstack, uses 1 stack space.
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pub unsafe fn get_main_state(state: *mut ffi::lua_State) -> Option<*mut ffi::lua_State> {
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#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
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{
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ffi::lua_rawgeti(state, ffi::LUA_REGISTRYINDEX, ffi::LUA_RIDX_MAINTHREAD);
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let main_state = ffi::lua_tothread(state, -1);
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ffi::lua_pop(state, 1);
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Some(main_state)
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}
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#[cfg(any(feature = "lua51", feature = "luajit"))]
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{
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// Check the current state first
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let is_main_state = ffi::lua_pushthread(state) == 1;
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ffi::lua_pop(state, 1);
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if is_main_state {
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Some(state)
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} else {
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None
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}
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}
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}
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// Pushes a WrappedError to the top of the stack.
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// Uses 2 stack spaces and does not call checkstack.
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pub unsafe fn push_wrapped_error(state: *mut ffi::lua_State, err: Error) -> Result<()> {
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let error_ud = ffi::safe::lua_newwrappederror(state)? as *mut WrappedError;
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ptr::write(error_ud, WrappedError(err, None));
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get_gc_metatable_for::<WrappedError>(state);
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ffi::lua_setmetatable(state, -2);
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Ok(())
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}
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// Checks if the value at the given index is a WrappedError, and if it is returns a pointer to it,
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// otherwise returns null.
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// Uses 2 stack spaces and does not call checkstack.
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pub unsafe fn get_wrapped_error(state: *mut ffi::lua_State, index: c_int) -> *const Error {
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let ud = get_gc_userdata::<WrappedError>(state, index);
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if ud.is_null() {
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return ptr::null();
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}
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&(*ud).0
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}
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// Initialize the internal (with __gc method) metatable for a type T.
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// Uses 6 stack spaces and calls checkstack.
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pub unsafe fn init_gc_metatable_for<T: Any>(
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state: *mut ffi::lua_State,
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customize_fn: Option<fn(*mut ffi::lua_State) -> Result<()>>,
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) -> Result<*const u8> {
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check_stack(state, 6)?;
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let type_id = TypeId::of::<T>();
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let ref_addr = {
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let mut mt_cache = mlua_expect!(METATABLE_CACHE.lock(), "cannot lock metatable cache");
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mlua_assert!(
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mt_cache.capacity() - mt_cache.len() > 0,
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"out of metatable cache capacity"
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);
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mt_cache.insert(type_id, 0);
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&mt_cache[&type_id] as *const u8
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};
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ffi::safe::lua_createtable(state, 0, 3)?;
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ffi::safe::lua_pushrclosure(state, userdata_destructor::<T>, 0)?;
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ffi::safe::lua_rawsetfield(state, -2, "__gc")?;
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ffi::lua_pushboolean(state, 0);
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ffi::safe::lua_rawsetfield(state, -2, "__metatable")?;
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if let Some(f) = customize_fn {
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f(state)?;
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}
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ffi::safe::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, ref_addr as *mut c_void)?;
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Ok(ref_addr)
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}
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pub unsafe fn get_gc_metatable_for<T: Any>(state: *mut ffi::lua_State) {
|
|
let type_id = TypeId::of::<T>();
|
|
let ref_addr = {
|
|
let mt_cache = mlua_expect!(METATABLE_CACHE.lock(), "cannot lock metatable cache");
|
|
mlua_expect!(mt_cache.get(&type_id), "gc metatable does not exist") as *const u8
|
|
};
|
|
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, ref_addr as *const c_void);
|
|
}
|
|
|
|
// Initialize the error, panic, and destructed userdata metatables.
|
|
// Returns address of WrappedError and WrappedPanic metatables in Lua registry.
|
|
pub unsafe fn init_error_registry(state: *mut ffi::lua_State) -> Result<(*const u8, *const u8)> {
|
|
check_stack(state, 7)?;
|
|
|
|
// Create error and panic metatables
|
|
|
|
unsafe extern "C" fn error_tostring(state: *mut ffi::lua_State) -> c_int {
|
|
callback_error(state, |_| {
|
|
check_stack(state, 3)?;
|
|
|
|
let wrapped_error = get_gc_userdata::<WrappedError>(state, -1).as_ref();
|
|
let err_buf = if let Some(error) = wrapped_error {
|
|
let err_buf_key = &ERROR_PRINT_BUFFER_KEY as *const u8 as *const c_void;
|
|
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, err_buf_key);
|
|
let err_buf = ffi::lua_touserdata(state, -1) as *mut String;
|
|
ffi::lua_pop(state, 2);
|
|
|
|
(*err_buf).clear();
|
|
// Depending on how the API is used and what error types scripts are given, it may
|
|
// be possible to make this consume arbitrary amounts of memory (for example, some
|
|
// kind of recursive error structure?)
|
|
let _ = write!(&mut (*err_buf), "{}", error.0);
|
|
match error {
|
|
WrappedError(Error::CallbackError { .. }, _) => {}
|
|
// This is a workaround to avoid having duplicate traceback for string errors
|
|
// with attached traceback at the `error_traceback` (message handler) stage.
|
|
WrappedError(Error::RuntimeError(ref err), _)
|
|
if err.contains("\nstack traceback:\n") => {}
|
|
WrappedError(_, Some(ref traceback)) => {
|
|
let _ = write!(&mut (*err_buf), "\n{}", traceback);
|
|
}
|
|
_ => {}
|
|
}
|
|
// Find first two sources that caused the error
|
|
let mut source1 = error.0.source();
|
|
let mut source0 = source1.and_then(|s| s.source());
|
|
while let Some(source) = source0.and_then(|s| s.source()) {
|
|
source1 = source0;
|
|
source0 = Some(source);
|
|
}
|
|
match (source1, source0) {
|
|
(_, Some(error0)) if error0.to_string().contains("\nstack traceback:\n") => {
|
|
let _ = write!(&mut (*err_buf), "\ncaused by: {}", error0);
|
|
}
|
|
(Some(error1), Some(error0)) => {
|
|
let _ = write!(&mut (*err_buf), "\ncaused by: {}", error0);
|
|
let s = error1.to_string();
|
|
if let Some(traceback) = s.splitn(2, "\nstack traceback:\n").nth(1) {
|
|
let _ = write!(&mut (*err_buf), "\nstack traceback:\n{}", traceback);
|
|
}
|
|
}
|
|
(Some(error1), None) => {
|
|
let _ = write!(&mut (*err_buf), "\ncaused by: {}", error1);
|
|
}
|
|
_ => {}
|
|
}
|
|
Ok(err_buf)
|
|
} else if let Some(panic) = get_gc_userdata::<WrappedPanic>(state, -1).as_ref() {
|
|
if let Some(ref p) = (*panic).0 {
|
|
let err_buf_key = &ERROR_PRINT_BUFFER_KEY as *const u8 as *const c_void;
|
|
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, err_buf_key);
|
|
let err_buf = ffi::lua_touserdata(state, -1) as *mut String;
|
|
(*err_buf).clear();
|
|
ffi::lua_pop(state, 2);
|
|
|
|
if let Some(msg) = p.downcast_ref::<&str>() {
|
|
let _ = write!(&mut (*err_buf), "{}", msg);
|
|
} else if let Some(msg) = p.downcast_ref::<String>() {
|
|
let _ = write!(&mut (*err_buf), "{}", msg);
|
|
} else {
|
|
let _ = write!(&mut (*err_buf), "<panic>");
|
|
};
|
|
Ok(err_buf)
|
|
} else {
|
|
Err(Error::PreviouslyResumedPanic)
|
|
}
|
|
} else {
|
|
// I'm not sure whether this is possible to trigger without bugs in mlua?
|
|
Err(Error::UserDataTypeMismatch)
|
|
}?;
|
|
|
|
ffi::safe::lua_pushstring(state, &*err_buf)?;
|
|
(*err_buf).clear();
|
|
|
|
Ok(1)
|
|
})
|
|
}
|
|
|
|
let wrapped_error_key = init_gc_metatable_for::<WrappedError>(
|
|
state,
|
|
Some(|state| {
|
|
ffi::safe::lua_pushrclosure(state, error_tostring, 0)?;
|
|
ffi::safe::lua_rawsetfield(state, -2, "__tostring")
|
|
}),
|
|
)?;
|
|
|
|
let wrapped_panic_key = init_gc_metatable_for::<WrappedPanic>(
|
|
state,
|
|
Some(|state| {
|
|
ffi::safe::lua_pushrclosure(state, error_tostring, 0)?;
|
|
ffi::safe::lua_rawsetfield(state, -2, "__tostring")
|
|
}),
|
|
)?;
|
|
|
|
// Create destructed userdata metatable
|
|
|
|
unsafe extern "C" fn destructed_error(state: *mut ffi::lua_State) -> c_int {
|
|
callback_error(state, |_| {
|
|
check_stack(state, 2)?;
|
|
let error_ud = ffi::safe::lua_newwrappederror(state)? as *mut WrappedError;
|
|
ptr::write(error_ud, WrappedError(Error::CallbackDestructed, None));
|
|
get_gc_metatable_for::<WrappedError>(state);
|
|
ffi::lua_setmetatable(state, -2);
|
|
Ok(-1) // to trigger lua_error
|
|
})
|
|
}
|
|
|
|
ffi::safe::lua_createtable(state, 0, 26)?;
|
|
ffi::safe::lua_pushrclosure(state, destructed_error, 0)?;
|
|
for &method in &[
|
|
"__add",
|
|
"__sub",
|
|
"__mul",
|
|
"__div",
|
|
"__mod",
|
|
"__pow",
|
|
"__unm",
|
|
#[cfg(any(feature = "lua54", feature = "lua53"))]
|
|
"__idiv",
|
|
#[cfg(any(feature = "lua54", feature = "lua53"))]
|
|
"__band",
|
|
#[cfg(any(feature = "lua54", feature = "lua53"))]
|
|
"__bor",
|
|
#[cfg(any(feature = "lua54", feature = "lua53"))]
|
|
"__bxor",
|
|
#[cfg(any(feature = "lua54", feature = "lua53"))]
|
|
"__bnot",
|
|
#[cfg(any(feature = "lua54", feature = "lua53"))]
|
|
"__shl",
|
|
#[cfg(any(feature = "lua54", feature = "lua53"))]
|
|
"__shr",
|
|
"__concat",
|
|
"__len",
|
|
"__eq",
|
|
"__lt",
|
|
"__le",
|
|
"__index",
|
|
"__newindex",
|
|
"__call",
|
|
"__tostring",
|
|
#[cfg(any(feature = "lua54", feature = "lua53", feature = "lua52"))]
|
|
"__pairs",
|
|
#[cfg(any(feature = "lua53", feature = "lua52"))]
|
|
"__ipairs",
|
|
#[cfg(feature = "lua54")]
|
|
"__close",
|
|
] {
|
|
ffi::lua_pushvalue(state, -1);
|
|
ffi::safe::lua_rawsetfield(state, -3, method)?;
|
|
}
|
|
ffi::lua_pop(state, 1);
|
|
|
|
let destructed_metatable_key = &DESTRUCTED_USERDATA_METATABLE as *const u8 as *const c_void;
|
|
ffi::safe::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, destructed_metatable_key)?;
|
|
|
|
// Create error print buffer
|
|
init_gc_metatable_for::<String>(state, None)?;
|
|
push_gc_userdata(state, String::new())?;
|
|
let err_buf_key = &ERROR_PRINT_BUFFER_KEY as *const u8 as *const c_void;
|
|
ffi::safe::lua_rawsetp(state, ffi::LUA_REGISTRYINDEX, err_buf_key)?;
|
|
|
|
Ok((wrapped_error_key, wrapped_panic_key))
|
|
}
|
|
|
|
pub(crate) struct WrappedError(pub Error, pub Option<String>);
|
|
pub(crate) struct WrappedPanic(pub Option<Box<dyn Any + Send + 'static>>);
|
|
|
|
// Converts the given lua value to a string in a reasonable format without causing a Lua error or
|
|
// panicking.
|
|
unsafe fn to_string(state: *mut ffi::lua_State, index: c_int) -> String {
|
|
match ffi::lua_type(state, index) {
|
|
ffi::LUA_TNONE => "<none>".to_string(),
|
|
ffi::LUA_TNIL => "<nil>".to_string(),
|
|
ffi::LUA_TBOOLEAN => (ffi::lua_toboolean(state, index) != 1).to_string(),
|
|
ffi::LUA_TLIGHTUSERDATA => {
|
|
format!("<lightuserdata {:?}>", ffi::lua_topointer(state, index))
|
|
}
|
|
ffi::LUA_TNUMBER => {
|
|
let mut isint = 0;
|
|
let i = ffi::lua_tointegerx(state, -1, &mut isint);
|
|
if isint == 0 {
|
|
ffi::lua_tonumber(state, index).to_string()
|
|
} else {
|
|
i.to_string()
|
|
}
|
|
}
|
|
ffi::LUA_TSTRING => {
|
|
let mut size = 0;
|
|
// This will not trigger a 'm' error, because the reference is guaranteed to be of
|
|
// string type
|
|
let data = ffi::lua_tolstring(state, index, &mut size);
|
|
String::from_utf8_lossy(slice::from_raw_parts(data as *const u8, size)).into_owned()
|
|
}
|
|
ffi::LUA_TTABLE => format!("<table {:?}>", ffi::lua_topointer(state, index)),
|
|
ffi::LUA_TFUNCTION => format!("<function {:?}>", ffi::lua_topointer(state, index)),
|
|
ffi::LUA_TUSERDATA => format!("<userdata {:?}>", ffi::lua_topointer(state, index)),
|
|
ffi::LUA_TTHREAD => format!("<thread {:?}>", ffi::lua_topointer(state, index)),
|
|
_ => "<unknown>".to_string(),
|
|
}
|
|
}
|
|
|
|
pub(crate) unsafe fn get_destructed_userdata_metatable(state: *mut ffi::lua_State) {
|
|
let key = &DESTRUCTED_USERDATA_METATABLE as *const u8 as *const c_void;
|
|
ffi::lua_rawgetp(state, ffi::LUA_REGISTRYINDEX, key);
|
|
}
|
|
|
|
static DESTRUCTED_USERDATA_METATABLE: u8 = 0;
|
|
static ERROR_PRINT_BUFFER_KEY: u8 = 0;
|