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author | Alex Orlenko <zxteam@protonmail.com> | 2021-05-11 14:18:22 +0100 |
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committer | Alex Orlenko <zxteam@protonmail.com> | 2021-05-11 14:18:22 +0100 |
commit | b610a79d66e1d2a07110f5e42458a9e42990ab12 (patch) | |
tree | 57b4f56bbf30046955bc49dd06ca7a6e90d490f6 | |
parent | fe39ae09bfe59788934e5d86bc44caa18c62e581 (diff) | |
download | mlua-b610a79d66e1d2a07110f5e42458a9e42990ab12.zip |
Update docs & minor error handling code changes
-rw-r--r-- | src/ffi/shim/shim.c | 45 | ||||
-rw-r--r-- | src/util.rs | 3 |
2 files changed, 20 insertions, 28 deletions
diff --git a/src/ffi/shim/shim.c b/src/ffi/shim/shim.c index c06b83a..fc77047 100644 --- a/src/ffi/shim/shim.c +++ b/src/ffi/shim/shim.c @@ -47,9 +47,21 @@ typedef struct { size_t len; } StringArg; +static void handle_wrapped_error(lua_State *L) { + if (lua_checkstack(L, LUA_TRACEBACK_STACK) != 0) { + luaL_traceback(L, L, NULL, 0); + // Convert to CallbackError and attach traceback + wrapped_error_traceback(L, -2, -1); + lua_pop(L, 1); + } else { + // Convert to CallbackError with error message as a traceback + wrapped_error_traceback(L, -1, 0); + } +} + // A wrapper around Rust function to protect from triggering longjmp in Rust. -// Rust callback expected to return -1 in case of errors or number of output -// values. +// Rust callback expected to return positive number of output values or +// -1 in case of error, -2 in case of panic. static int lua_call_rust(lua_State *L) { int nargs = lua_gettop(L); @@ -73,15 +85,7 @@ static int lua_call_rust(lua_State *L) { int ret = rust_callback(L); if (ret < 0) { if (ret == -1 /* WrappedError */) { - if (lua_checkstack(L, LUA_TRACEBACK_STACK) != 0) { - luaL_traceback(L, L, NULL, 0); - // Convert to CallbackError and attach traceback - wrapped_error_traceback(L, -2, -1); - lua_pop(L, 1); - } else { - // Convert to CallbackError with error message as a traceback - wrapped_error_traceback(L, -1, 0); - } + handle_wrapped_error(L); } lua_error(L); } @@ -96,15 +100,7 @@ void lua_call_mlua_hook_proc(lua_State *L, lua_Debug *ar) { int ret = mlua_hook_proc(L, ar); if (ret < 0) { if (ret == -1 /* WrappedError */) { - if (lua_checkstack(L, LUA_TRACEBACK_STACK) != 0) { - luaL_traceback(L, L, NULL, 0); - // Convert to CallbackError and attach traceback - wrapped_error_traceback(L, -2, -1); - lua_pop(L, 1); - } else { - // Convert to CallbackError with error message as a traceback - wrapped_error_traceback(L, -1, 0); - } + handle_wrapped_error(L); } lua_error(L); } @@ -419,13 +415,10 @@ int is_wrapped_struct(lua_State *state, int index, const void *key) { return res; } -// Takes an error at the top of the stack, and if it is a WrappedError, converts -// it to an Error::CallbackError with a traceback, if it is some lua type, -// prints the error along with a traceback, and if it is a WrappedPanic, does +// Takes an error at the top of the stack and converts Lua errors into a string +// with attached traceback. If the error is a WrappedError or WrappedPanic, does // not modify it. This function does its best to avoid triggering another error -// and shadowing previous rust errors, but it may trigger Lua errors that shadow -// rust errors under certain memory conditions. This function ensures that such -// behavior will *never* occur with a rust panic, however. +// and shadowing previous rust errors. int error_traceback(lua_State *state) { if (lua_checkstack(state, 2) == 0) { // If we don't have enough stack space to even check the error type, do diff --git a/src/util.rs b/src/util.rs index 27edb21..f99c03f 100644 --- a/src/util.rs +++ b/src/util.rs @@ -331,8 +331,7 @@ where // A part of the C shim for errors handling. // Receives indexes of error and traceback (optional) in the stack. -// Depending on `convert_to_callback_error` flag attaches traceback to the error or -// converts error into a `CallbackError` (using previously attached traceback). +// Converts error into a `CallbackError` and attaches the traceback provided. #[no_mangle] pub unsafe extern "C" fn wrapped_error_traceback( state: *mut ffi::lua_State, |