xref: /wasmtime-44.0.1/crates/c-api/src/trap.rs (revision bb3de558)
1 use crate::{wasm_frame_vec_t, wasm_instance_t, wasm_name_t, wasm_store_t};
2 use std::cell::OnceCell;
3 use wasmtime::{Error, Trap, WasmBacktrace, format_err};
4 
5 // Help ensure the Rust enum matches the C one.  If any of these assertions
6 // fail, please update both this code and `trap.h` to sync them with
7 // `trap_encoding.rs`.
8 const _: () = {
9     assert!(Trap::StackOverflow as u8 == 0);
10     assert!(Trap::MemoryOutOfBounds as u8 == 1);
11     assert!(Trap::HeapMisaligned as u8 == 2);
12     assert!(Trap::TableOutOfBounds as u8 == 3);
13     assert!(Trap::IndirectCallToNull as u8 == 4);
14     assert!(Trap::BadSignature as u8 == 5);
15     assert!(Trap::IntegerOverflow as u8 == 6);
16     assert!(Trap::IntegerDivisionByZero as u8 == 7);
17     assert!(Trap::BadConversionToInteger as u8 == 8);
18     assert!(Trap::UnreachableCodeReached as u8 == 9);
19     assert!(Trap::Interrupt as u8 == 10);
20     assert!(Trap::OutOfFuel as u8 == 11);
21     assert!(Trap::AtomicWaitNonSharedMemory as u8 == 12);
22     assert!(Trap::NullReference as u8 == 13);
23     assert!(Trap::ArrayOutOfBounds as u8 == 14);
24     assert!(Trap::AllocationTooLarge as u8 == 15);
25     assert!(Trap::CastFailure as u8 == 16);
26     assert!(Trap::CannotEnterComponent as u8 == 17);
27     assert!(Trap::NoAsyncResult as u8 == 18);
28     assert!(Trap::UnhandledTag as u8 == 19);
29     assert!(Trap::ContinuationAlreadyConsumed as u8 == 20);
30     assert!(Trap::DisabledOpcode as u8 == 21);
31     assert!(Trap::AsyncDeadlock as u8 == 22);
32     assert!(Trap::CannotLeaveComponent as u8 == 23);
33     assert!(Trap::CannotBlockSyncTask as u8 == 24);
34     assert!(Trap::InvalidChar as u8 == 25);
35     assert!(Trap::DebugAssertStringEncodingFinished as u8 == 26);
36     assert!(Trap::DebugAssertEqualCodeUnits as u8 == 27);
37     assert!(Trap::DebugAssertPointerAligned as u8 == 28);
38     assert!(Trap::DebugAssertUpperBitsUnset as u8 == 29);
39     assert!(Trap::StringOutOfBounds as u8 == 30);
40     assert!(Trap::ListOutOfBounds as u8 == 31);
41     assert!(Trap::InvalidDiscriminant as u8 == 32);
42     assert!(Trap::UnalignedPointer as u8 == 33);
43     assert!(Trap::TaskCancelNotCancelled as u8 == 34);
44     assert!(Trap::TaskCancelOrReturnTwice as u8 == 35);
45     assert!(Trap::SubtaskCancelAfterTerminal as u8 == 36);
46     assert!(Trap::TaskReturnInvalid as u8 == 37);
47     assert!(Trap::WaitableSetDropHasWaiters as u8 == 38);
48     assert!(Trap::SubtaskDropNotResolved as u8 == 39);
49     assert!(Trap::ThreadNewIndirectInvalidType as u8 == 40);
50     assert!(Trap::ThreadNewIndirectUninitialized as u8 == 41);
51     assert!(Trap::BackpressureOverflow as u8 == 42);
52     assert!(Trap::UnsupportedCallbackCode as u8 == 43);
53     assert!(Trap::CannotResumeThread as u8 == 44);
54 };
55 
56 #[repr(C)]
57 pub struct wasm_trap_t {
58     pub(crate) error: Error,
59 }
60 
61 // This is currently only needed for the `wasm_trap_copy` API in the C API.
62 //
63 // For now the impl here is "fake it til you make it" since this is losing
64 // context by only cloning the error string.
65 impl Clone for wasm_trap_t {
66     fn clone(&self) -> wasm_trap_t {
67         wasm_trap_t {
68             error: format_err!("{:?}", self.error),
69         }
70     }
71 }
72 
73 wasmtime_c_api_macros::declare_ref!(wasm_trap_t);
74 
75 impl wasm_trap_t {
76     pub(crate) fn new(error: Error) -> wasm_trap_t {
77         wasm_trap_t { error }
78     }
79 }
80 
81 #[repr(C)]
82 #[derive(Clone)]
83 pub struct wasm_frame_t<'a> {
84     trace: &'a WasmBacktrace,
85     idx: usize,
86     func_name: OnceCell<Option<wasm_name_t>>,
87     module_name: OnceCell<Option<wasm_name_t>>,
88 }
89 
90 wasmtime_c_api_macros::declare_own!(wasm_frame_t);
91 
92 pub type wasm_message_t = wasm_name_t;
93 
94 #[unsafe(no_mangle)]
95 pub extern "C" fn wasm_trap_new(
96     _store: &wasm_store_t,
97     message: &wasm_message_t,
98 ) -> Box<wasm_trap_t> {
99     let message = message.as_slice();
100     if message[message.len() - 1] != 0 {
101         panic!("wasm_trap_new message stringz expected");
102     }
103     let message = String::from_utf8_lossy(&message[..message.len() - 1]);
104     Box::new(wasm_trap_t {
105         error: Error::msg(message.into_owned()),
106     })
107 }
108 
109 #[unsafe(no_mangle)]
110 pub unsafe extern "C" fn wasmtime_trap_new(message: *const u8, len: usize) -> Box<wasm_trap_t> {
111     let bytes = crate::slice_from_raw_parts(message, len);
112     let message = String::from_utf8_lossy(&bytes);
113     Box::new(wasm_trap_t {
114         error: Error::msg(message.into_owned()),
115     })
116 }
117 
118 #[unsafe(no_mangle)]
119 pub unsafe extern "C" fn wasmtime_trap_new_code(code: u8) -> Box<wasm_trap_t> {
120     let trap = Trap::from_u8(code).unwrap();
121     Box::new(wasm_trap_t {
122         error: Error::new(trap),
123     })
124 }
125 
126 #[unsafe(no_mangle)]
127 pub extern "C" fn wasm_trap_message(trap: &wasm_trap_t, out: &mut wasm_message_t) {
128     let mut buffer = Vec::new();
129     buffer.extend_from_slice(format!("{:?}", trap.error).as_bytes());
130     buffer.reserve_exact(1);
131     buffer.push(0);
132     out.set_buffer(buffer);
133 }
134 
135 #[unsafe(no_mangle)]
136 pub extern "C" fn wasm_trap_origin(raw: &wasm_trap_t) -> Option<Box<wasm_frame_t<'_>>> {
137     let trace = match raw.error.downcast_ref::<WasmBacktrace>() {
138         Some(trap) => trap,
139         None => return None,
140     };
141     if trace.frames().len() > 0 {
142         Some(Box::new(wasm_frame_t {
143             trace,
144             idx: 0,
145             func_name: OnceCell::new(),
146             module_name: OnceCell::new(),
147         }))
148     } else {
149         None
150     }
151 }
152 
153 #[unsafe(no_mangle)]
154 pub extern "C" fn wasm_trap_trace<'a>(raw: &'a wasm_trap_t, out: &mut wasm_frame_vec_t<'a>) {
155     error_trace(&raw.error, out)
156 }
157 
158 pub(crate) fn error_trace<'a>(error: &'a Error, out: &mut wasm_frame_vec_t<'a>) {
159     let trace = match error.downcast_ref::<WasmBacktrace>() {
160         Some(trap) => trap,
161         None => return out.set_buffer(Vec::new()),
162     };
163     let vec = (0..trace.frames().len())
164         .map(|idx| {
165             Some(Box::new(wasm_frame_t {
166                 trace,
167                 idx,
168                 func_name: OnceCell::new(),
169                 module_name: OnceCell::new(),
170             }))
171         })
172         .collect();
173     out.set_buffer(vec);
174 }
175 
176 #[unsafe(no_mangle)]
177 pub extern "C" fn wasmtime_trap_code(raw: &wasm_trap_t, code: &mut u8) -> bool {
178     let trap = match raw.error.downcast_ref::<Trap>() {
179         Some(trap) => trap,
180         None => return false,
181     };
182     *code = *trap as u8;
183     true
184 }
185 
186 #[unsafe(no_mangle)]
187 pub extern "C" fn wasm_frame_func_index(frame: &wasm_frame_t<'_>) -> u32 {
188     frame.trace.frames()[frame.idx].func_index()
189 }
190 
191 #[unsafe(no_mangle)]
192 pub extern "C" fn wasmtime_frame_func_name<'a>(
193     frame: &'a wasm_frame_t<'_>,
194 ) -> Option<&'a wasm_name_t> {
195     frame
196         .func_name
197         .get_or_init(|| {
198             frame.trace.frames()[frame.idx]
199                 .func_name()
200                 .map(|s| wasm_name_t::from(s.to_string().into_bytes()))
201         })
202         .as_ref()
203 }
204 
205 #[unsafe(no_mangle)]
206 pub extern "C" fn wasmtime_frame_module_name<'a>(
207     frame: &'a wasm_frame_t<'_>,
208 ) -> Option<&'a wasm_name_t> {
209     frame
210         .module_name
211         .get_or_init(|| {
212             frame.trace.frames()[frame.idx]
213                 .module()
214                 .name()
215                 .map(|s| wasm_name_t::from(s.to_string().into_bytes()))
216         })
217         .as_ref()
218 }
219 
220 #[unsafe(no_mangle)]
221 pub extern "C" fn wasm_frame_func_offset(frame: &wasm_frame_t<'_>) -> usize {
222     frame.trace.frames()[frame.idx]
223         .func_offset()
224         .unwrap_or(usize::MAX)
225 }
226 
227 #[unsafe(no_mangle)]
228 pub extern "C" fn wasm_frame_instance(_arg1: *const wasm_frame_t<'_>) -> *mut wasm_instance_t {
229     unimplemented!("wasm_frame_instance")
230 }
231 
232 #[unsafe(no_mangle)]
233 pub extern "C" fn wasm_frame_module_offset(frame: &wasm_frame_t<'_>) -> usize {
234     frame.trace.frames()[frame.idx]
235         .module_offset()
236         .unwrap_or(usize::MAX)
237 }
238 
239 #[unsafe(no_mangle)]
240 pub extern "C" fn wasm_frame_copy<'a>(frame: &wasm_frame_t<'a>) -> Box<wasm_frame_t<'a>> {
241     Box::new(frame.clone())
242 }
243