1 use crate::{wasm_frame_vec_t, wasm_instance_t, wasm_name_t, wasm_store_t}; 2 use anyhow::{Error, anyhow}; 3 use std::cell::OnceCell; 4 use wasmtime::{Trap, WasmBacktrace}; 5 6 #[repr(C)] 7 pub struct wasm_trap_t { 8 pub(crate) error: Error, 9 } 10 11 // This is currently only needed for the `wasm_trap_copy` API in the C API. 12 // 13 // For now the impl here is "fake it til you make it" since this is losing 14 // context by only cloning the error string. 15 impl Clone for wasm_trap_t { 16 fn clone(&self) -> wasm_trap_t { 17 wasm_trap_t { 18 error: anyhow!("{:?}", self.error), 19 } 20 } 21 } 22 23 wasmtime_c_api_macros::declare_ref!(wasm_trap_t); 24 25 impl wasm_trap_t { 26 pub(crate) fn new(error: Error) -> wasm_trap_t { 27 wasm_trap_t { error } 28 } 29 } 30 31 #[repr(C)] 32 #[derive(Clone)] 33 pub struct wasm_frame_t<'a> { 34 trace: &'a WasmBacktrace, 35 idx: usize, 36 func_name: OnceCell<Option<wasm_name_t>>, 37 module_name: OnceCell<Option<wasm_name_t>>, 38 } 39 40 wasmtime_c_api_macros::declare_own!(wasm_frame_t); 41 42 pub type wasm_message_t = wasm_name_t; 43 44 #[unsafe(no_mangle)] 45 pub extern "C" fn wasm_trap_new( 46 _store: &wasm_store_t, 47 message: &wasm_message_t, 48 ) -> Box<wasm_trap_t> { 49 let message = message.as_slice(); 50 if message[message.len() - 1] != 0 { 51 panic!("wasm_trap_new message stringz expected"); 52 } 53 let message = String::from_utf8_lossy(&message[..message.len() - 1]); 54 Box::new(wasm_trap_t { 55 error: Error::msg(message.into_owned()), 56 }) 57 } 58 59 #[unsafe(no_mangle)] 60 pub unsafe extern "C" fn wasmtime_trap_new(message: *const u8, len: usize) -> Box<wasm_trap_t> { 61 let bytes = crate::slice_from_raw_parts(message, len); 62 let message = String::from_utf8_lossy(&bytes); 63 Box::new(wasm_trap_t { 64 error: Error::msg(message.into_owned()), 65 }) 66 } 67 68 #[unsafe(no_mangle)] 69 pub unsafe extern "C" fn wasmtime_trap_new_code(code: u8) -> Box<wasm_trap_t> { 70 let trap = Trap::from_u8(code).unwrap(); 71 Box::new(wasm_trap_t { 72 error: Error::new(trap), 73 }) 74 } 75 76 #[unsafe(no_mangle)] 77 pub extern "C" fn wasm_trap_message(trap: &wasm_trap_t, out: &mut wasm_message_t) { 78 let mut buffer = Vec::new(); 79 buffer.extend_from_slice(format!("{:?}", trap.error).as_bytes()); 80 buffer.reserve_exact(1); 81 buffer.push(0); 82 out.set_buffer(buffer); 83 } 84 85 #[unsafe(no_mangle)] 86 pub extern "C" fn wasm_trap_origin(raw: &wasm_trap_t) -> Option<Box<wasm_frame_t<'_>>> { 87 let trace = match raw.error.downcast_ref::<WasmBacktrace>() { 88 Some(trap) => trap, 89 None => return None, 90 }; 91 if trace.frames().len() > 0 { 92 Some(Box::new(wasm_frame_t { 93 trace, 94 idx: 0, 95 func_name: OnceCell::new(), 96 module_name: OnceCell::new(), 97 })) 98 } else { 99 None 100 } 101 } 102 103 #[unsafe(no_mangle)] 104 pub extern "C" fn wasm_trap_trace<'a>(raw: &'a wasm_trap_t, out: &mut wasm_frame_vec_t<'a>) { 105 error_trace(&raw.error, out) 106 } 107 108 pub(crate) fn error_trace<'a>(error: &'a Error, out: &mut wasm_frame_vec_t<'a>) { 109 let trace = match error.downcast_ref::<WasmBacktrace>() { 110 Some(trap) => trap, 111 None => return out.set_buffer(Vec::new()), 112 }; 113 let vec = (0..trace.frames().len()) 114 .map(|idx| { 115 Some(Box::new(wasm_frame_t { 116 trace, 117 idx, 118 func_name: OnceCell::new(), 119 module_name: OnceCell::new(), 120 })) 121 }) 122 .collect(); 123 out.set_buffer(vec); 124 } 125 126 #[unsafe(no_mangle)] 127 pub extern "C" fn wasmtime_trap_code(raw: &wasm_trap_t, code: &mut u8) -> bool { 128 let trap = match raw.error.downcast_ref::<Trap>() { 129 Some(trap) => trap, 130 None => return false, 131 }; 132 *code = *trap as u8; 133 true 134 } 135 136 #[unsafe(no_mangle)] 137 pub extern "C" fn wasm_frame_func_index(frame: &wasm_frame_t<'_>) -> u32 { 138 frame.trace.frames()[frame.idx].func_index() 139 } 140 141 #[unsafe(no_mangle)] 142 pub extern "C" fn wasmtime_frame_func_name<'a>( 143 frame: &'a wasm_frame_t<'_>, 144 ) -> Option<&'a wasm_name_t> { 145 frame 146 .func_name 147 .get_or_init(|| { 148 frame.trace.frames()[frame.idx] 149 .func_name() 150 .map(|s| wasm_name_t::from(s.to_string().into_bytes())) 151 }) 152 .as_ref() 153 } 154 155 #[unsafe(no_mangle)] 156 pub extern "C" fn wasmtime_frame_module_name<'a>( 157 frame: &'a wasm_frame_t<'_>, 158 ) -> Option<&'a wasm_name_t> { 159 frame 160 .module_name 161 .get_or_init(|| { 162 frame.trace.frames()[frame.idx] 163 .module() 164 .name() 165 .map(|s| wasm_name_t::from(s.to_string().into_bytes())) 166 }) 167 .as_ref() 168 } 169 170 #[unsafe(no_mangle)] 171 pub extern "C" fn wasm_frame_func_offset(frame: &wasm_frame_t<'_>) -> usize { 172 frame.trace.frames()[frame.idx] 173 .func_offset() 174 .unwrap_or(usize::MAX) 175 } 176 177 #[unsafe(no_mangle)] 178 pub extern "C" fn wasm_frame_instance(_arg1: *const wasm_frame_t<'_>) -> *mut wasm_instance_t { 179 unimplemented!("wasm_frame_instance") 180 } 181 182 #[unsafe(no_mangle)] 183 pub extern "C" fn wasm_frame_module_offset(frame: &wasm_frame_t<'_>) -> usize { 184 frame.trace.frames()[frame.idx] 185 .module_offset() 186 .unwrap_or(usize::MAX) 187 } 188 189 #[unsafe(no_mangle)] 190 pub extern "C" fn wasm_frame_copy<'a>(frame: &wasm_frame_t<'a>) -> Box<wasm_frame_t<'a>> { 191 Box::new(frame.clone()) 192 } 193