Deduplicate listings of traps in Wasmtime (#5299)

This commit replaces `wasmtime_environ::TrapCode` with `wasmtime::Trap`.
This is possible with past refactorings which slimmed down the `Trap`
definition in the `wasmtime` crate to a simple `enum`. This means that
there's one less place that all the various trap opcodes need to be
listed in Wasmtime.

crates/cranelift/src/compiler.rs

@@ -32,7 +32,7 @@ use std::sync::{Arc, Mutex};
 use wasmparser::{FuncValidatorAllocations, FunctionBody};
 use wasmtime_environ::{
     AddressMapSection, CacheStore, CompileError, FilePos, FlagValue, FunctionBodyData, FunctionLoc,
-    InstructionAddressMap, ModuleTranslation, ModuleTypes, PtrSize, StackMapInformation, TrapCode,
+    InstructionAddressMap, ModuleTranslation, ModuleTypes, PtrSize, StackMapInformation, Trap,
     TrapEncodingBuilder, TrapInformation, Tunables, VMOffsets, WasmFunctionInfo,
 };
 
@@ -1003,18 +1003,18 @@ fn mach_trap_to_trap(trap: &MachTrap) -> TrapInformation {
     TrapInformation {
         code_offset: offset,
         trap_code: match code {
-            ir::TrapCode::StackOverflow => TrapCode::StackOverflow,
+            ir::TrapCode::StackOverflow => Trap::StackOverflow,
-            ir::TrapCode::HeapOutOfBounds => TrapCode::HeapOutOfBounds,
+            ir::TrapCode::HeapOutOfBounds => Trap::MemoryOutOfBounds,
-            ir::TrapCode::HeapMisaligned => TrapCode::HeapMisaligned,
+            ir::TrapCode::HeapMisaligned => Trap::HeapMisaligned,
-            ir::TrapCode::TableOutOfBounds => TrapCode::TableOutOfBounds,
+            ir::TrapCode::TableOutOfBounds => Trap::TableOutOfBounds,
-            ir::TrapCode::IndirectCallToNull => TrapCode::IndirectCallToNull,
+            ir::TrapCode::IndirectCallToNull => Trap::IndirectCallToNull,
-            ir::TrapCode::BadSignature => TrapCode::BadSignature,
+            ir::TrapCode::BadSignature => Trap::BadSignature,
-            ir::TrapCode::IntegerOverflow => TrapCode::IntegerOverflow,
+            ir::TrapCode::IntegerOverflow => Trap::IntegerOverflow,
-            ir::TrapCode::IntegerDivisionByZero => TrapCode::IntegerDivisionByZero,
+            ir::TrapCode::IntegerDivisionByZero => Trap::IntegerDivisionByZero,
-            ir::TrapCode::BadConversionToInteger => TrapCode::BadConversionToInteger,
+            ir::TrapCode::BadConversionToInteger => Trap::BadConversionToInteger,
-            ir::TrapCode::UnreachableCodeReached => TrapCode::UnreachableCodeReached,
+            ir::TrapCode::UnreachableCodeReached => Trap::UnreachableCodeReached,
-            ir::TrapCode::Interrupt => TrapCode::Interrupt,
+            ir::TrapCode::Interrupt => Trap::Interrupt,
-            ir::TrapCode::User(ALWAYS_TRAP_CODE) => TrapCode::AlwaysTrapAdapter,
+            ir::TrapCode::User(ALWAYS_TRAP_CODE) => Trap::AlwaysTrapAdapter,
 
             // these should never be emitted by wasmtime-cranelift
             ir::TrapCode::User(_) => unreachable!(),

crates/environ/src/trap_encoding.rs

@@ -2,6 +2,7 @@ use crate::obj::ELF_WASMTIME_TRAPS;
 use object::write::{Object, StandardSegment};
 use object::{Bytes, LittleEndian, SectionKind, U32Bytes};
 use std::convert::TryFrom;
+use std::fmt;
 use std::ops::Range;
 
 /// A helper structure to build the custom-encoded section of a wasmtime
@@ -26,29 +27,30 @@ pub struct TrapInformation {
     pub code_offset: u32,
 
     /// Code of the trap.
-    pub trap_code: TrapCode,
+    pub trap_code: Trap,
 }
 
-/// A trap code describing the reason for a trap.
+// The code can be accessed from the c-api, where the possible values are
-///
+// translated into enum values defined there:
-/// All trap instructions have an explicit trap code.
+//
+// * `wasm_trap_code` in c-api/src/trap.rs, and
+// * `wasmtime_trap_code_enum` in c-api/include/wasmtime/trap.h.
+//
+// These need to be kept in sync.
+#[non_exhaustive]
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
-#[repr(u8)]
+#[allow(missing_docs)]
-pub enum TrapCode {
+pub enum Trap {
     /// The current stack space was exhausted.
     StackOverflow,
 
-    /// A `heap_addr` instruction detected an out-of-bounds error.
+    /// An out-of-bounds memory access.
-    ///
+    MemoryOutOfBounds,
-    /// Note that not all out-of-bounds heap accesses are reported this way;
-    /// some are detected by a segmentation fault on the heap unmapped or
-    /// offset-guard pages.
-    HeapOutOfBounds,
 
     /// A wasm atomic operation was presented with a not-naturally-aligned linear-memory address.
     HeapMisaligned,
 
-    /// A `table_addr` instruction detected an out-of-bounds error.
+    /// An out-of-bounds access to a table.
     TableOutOfBounds,
 
     /// Indirect call to a null table entry.
@@ -70,15 +72,45 @@ pub enum TrapCode {
     UnreachableCodeReached,
 
     /// Execution has potentially run too long and may be interrupted.
-    /// This trap is resumable.
     Interrupt,
 
-    /// Used for the component model when functions are lifted/lowered in a way
+    /// When the `component-model` feature is enabled this trap represents a
-    /// that generates a function that always traps.
+    /// function that was `canon lift`'d, then `canon lower`'d, then called.
+    /// This combination of creation of a function in the component model
+    /// generates a function that always traps and, when called, produces this
+    /// flavor of trap.
     AlwaysTrapAdapter,
-    // if adding a variant here be sure to update the `check!` macro below
+
+    /// When wasm code is configured to consume fuel and it runs out of fuel
+    /// then this trap will be raised.
+    OutOfFuel,
 }
 
+impl fmt::Display for Trap {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        use Trap::*;
+
+        let desc = match self {
+            StackOverflow => "call stack exhausted",
+            MemoryOutOfBounds => "out of bounds memory access",
+            HeapMisaligned => "misaligned memory access",
+            TableOutOfBounds => "undefined element: out of bounds table access",
+            IndirectCallToNull => "uninitialized element",
+            BadSignature => "indirect call type mismatch",
+            IntegerOverflow => "integer overflow",
+            IntegerDivisionByZero => "integer divide by zero",
+            BadConversionToInteger => "invalid conversion to integer",
+            UnreachableCodeReached => "wasm `unreachable` instruction executed",
+            Interrupt => "interrupt",
+            AlwaysTrapAdapter => "degenerate component adapter called",
+            OutOfFuel => "all fuel consumed by WebAssembly",
+        };
+        write!(f, "wasm trap: {desc}")
+    }
+}
+
+impl std::error::Error for Trap {}
+
 impl TrapEncodingBuilder {
     /// Appends trap information about a function into this section.
     ///
@@ -136,7 +168,7 @@ impl TrapEncodingBuilder {
 /// The `section` provided is expected to have been built by
 /// `TrapEncodingBuilder` above. Additionally the `offset` should be a relative
 /// offset within the text section of the compilation image.
-pub fn lookup_trap_code(section: &[u8], offset: usize) -> Option<TrapCode> {
+pub fn lookup_trap_code(section: &[u8], offset: usize) -> Option<Trap> {
     let mut section = Bytes(section);
     // NB: this matches the encoding written by `append_to` above.
     let count = section.read::<U32Bytes<LittleEndian>>().ok()?;
@@ -164,16 +196,16 @@ pub fn lookup_trap_code(section: &[u8], offset: usize) -> Option<TrapCode> {
     // FIXME: this could use some sort of derive-like thing to avoid having to
     // deduplicate the names here.
     //
-    // This simply converts from the `trap`, a `u8`, to the `TrapCode` enum.
+    // This simply converts from the `trap`, a `u8`, to the `Trap` enum.
     macro_rules! check {
-        ($($name:ident)*) => ($(if trap == TrapCode::$name as u8 {
+        ($($name:ident)*) => ($(if trap == Trap::$name as u8 {
-            return Some(TrapCode::$name);
+            return Some(Trap::$name);
         })*);
     }
 
     check! {
         StackOverflow
-        HeapOutOfBounds
+        MemoryOutOfBounds
         HeapMisaligned
         TableOutOfBounds
         IndirectCallToNull
@@ -184,6 +216,7 @@ pub fn lookup_trap_code(section: &[u8], offset: usize) -> Option<TrapCode> {
         UnreachableCodeReached
         Interrupt
         AlwaysTrapAdapter
+        OutOfFuel
     }
 
     if cfg!(debug_assertions) {

crates/runtime/src/instance.rs

@@ -30,7 +30,7 @@ use wasmtime_environ::{
     packed_option::ReservedValue, DataIndex, DefinedGlobalIndex, DefinedMemoryIndex,
     DefinedTableIndex, ElemIndex, EntityIndex, EntityRef, EntitySet, FuncIndex, GlobalIndex,
     GlobalInit, HostPtr, MemoryIndex, Module, PrimaryMap, SignatureIndex, TableIndex,
-    TableInitialization, TrapCode, VMOffsets, WasmType,
+    TableInitialization, Trap, VMOffsets, WasmType,
 };
 
 mod allocator;
@@ -580,7 +580,7 @@ impl Instance {
         dst: u32,
         src: u32,
         len: u32,
-    ) -> Result<(), TrapCode> {
+    ) -> Result<(), Trap> {
         // TODO: this `clone()` shouldn't be necessary but is used for now to
         // inform `rustc` that the lifetime of the elements here are
         // disconnected from the lifetime of `self`.
@@ -602,7 +602,7 @@ impl Instance {
         dst: u32,
         src: u32,
         len: u32,
-    ) -> Result<(), TrapCode> {
+    ) -> Result<(), Trap> {
         // https://webassembly.github.io/bulk-memory-operations/core/exec/instructions.html#exec-table-init
 
         let table = unsafe { &mut *self.get_table(table_index) };
@@ -612,7 +612,7 @@ impl Instance {
             .and_then(|s| s.get(..usize::try_from(len).unwrap()))
         {
             Some(elements) => elements,
-            None => return Err(TrapCode::TableOutOfBounds),
+            None => return Err(Trap::TableOutOfBounds),
         };
 
         match table.element_type() {
@@ -662,7 +662,7 @@ impl Instance {
         src_index: MemoryIndex,
         src: u64,
         len: u64,
-    ) -> Result<(), TrapCode> {
+    ) -> Result<(), Trap> {
         // https://webassembly.github.io/reference-types/core/exec/instructions.html#exec-memory-copy
 
         let src_mem = self.get_memory(src_index);
@@ -684,8 +684,8 @@ impl Instance {
         Ok(())
     }
 
-    fn validate_inbounds(&self, max: usize, ptr: u64, len: u64) -> Result<usize, TrapCode> {
+    fn validate_inbounds(&self, max: usize, ptr: u64, len: u64) -> Result<usize, Trap> {
-        let oob = || TrapCode::HeapOutOfBounds;
+        let oob = || Trap::MemoryOutOfBounds;
         let end = ptr
             .checked_add(len)
             .and_then(|i| usize::try_from(i).ok())
@@ -708,7 +708,7 @@ impl Instance {
         dst: u64,
         val: u8,
         len: u64,
-    ) -> Result<(), TrapCode> {
+    ) -> Result<(), Trap> {
         let memory = self.get_memory(memory_index);
         let dst = self.validate_inbounds(memory.current_length(), dst, len)?;
 
@@ -738,7 +738,7 @@ impl Instance {
         dst: u64,
         src: u32,
         len: u32,
-    ) -> Result<(), TrapCode> {
+    ) -> Result<(), Trap> {
         let range = match self.module().passive_data_map.get(&data_index).cloned() {
             Some(range) if !self.dropped_data.contains(data_index) => range,
             _ => 0..0,
@@ -757,7 +757,7 @@ impl Instance {
         dst: u64,
         src: u32,
         len: u32,
-    ) -> Result<(), TrapCode> {
+    ) -> Result<(), Trap> {
         // https://webassembly.github.io/bulk-memory-operations/core/exec/instructions.html#exec-memory-init
 
         let memory = self.get_memory(memory_index);

crates/runtime/src/instance/allocator.rs

@@ -13,8 +13,8 @@ use std::sync::Arc;
 use thiserror::Error;
 use wasmtime_environ::{
     DefinedMemoryIndex, DefinedTableIndex, HostPtr, InitMemory, MemoryInitialization,
-    MemoryInitializer, Module, PrimaryMap, TableInitialization, TableInitializer, TrapCode,
+    MemoryInitializer, Module, PrimaryMap, TableInitialization, TableInitializer, Trap, VMOffsets,
-    VMOffsets, WasmType, WASM_PAGE_SIZE,
+    WasmType, WASM_PAGE_SIZE,
 };
 
 #[cfg(feature = "pooling-allocator")]
@@ -105,7 +105,7 @@ pub enum InstantiationError {
 
     /// A trap ocurred during instantiation, after linking.
     #[error("Trap occurred during instantiation")]
-    Trap(TrapCode),
+    Trap(Trap),
 
     /// A limit on how many instances are supported has been reached.
     #[error("Limit of {0} concurrent instances has been reached")]
@@ -386,7 +386,7 @@ fn initialize_memories(instance: &mut Instance, module: &Module) -> Result<(), I
         },
     );
     if !ok {
-        return Err(InstantiationError::Trap(TrapCode::HeapOutOfBounds));
+        return Err(InstantiationError::Trap(Trap::MemoryOutOfBounds));
     }
 
     Ok(())

crates/runtime/src/libcalls.rs

@@ -63,7 +63,7 @@ use anyhow::Result;
 use std::mem;
 use std::ptr::{self, NonNull};
 use wasmtime_environ::{
-    DataIndex, ElemIndex, FuncIndex, GlobalIndex, MemoryIndex, TableIndex, TrapCode,
+    DataIndex, ElemIndex, FuncIndex, GlobalIndex, MemoryIndex, TableIndex, Trap,
 };
 
 /// Actually public trampolines which are used by the runtime as the entrypoint
@@ -228,7 +228,7 @@ unsafe fn table_fill(
     // `VMCallerCheckedAnyfunc` until we look at the table's element type.
     val: *mut u8,
     len: u32,
-) -> Result<(), TrapCode> {
+) -> Result<(), Trap> {
     let instance = (*vmctx).instance_mut();
     let table_index = TableIndex::from_u32(table_index);
     let table = &mut *instance.get_table(table_index);
@@ -259,7 +259,7 @@ unsafe fn table_copy(
     dst: u32,
     src: u32,
     len: u32,
-) -> Result<(), TrapCode> {
+) -> Result<(), Trap> {
     let dst_table_index = TableIndex::from_u32(dst_table_index);
     let src_table_index = TableIndex::from_u32(src_table_index);
     let instance = (*vmctx).instance_mut();
@@ -278,7 +278,7 @@ unsafe fn table_init(
     dst: u32,
     src: u32,
     len: u32,
-) -> Result<(), TrapCode> {
+) -> Result<(), Trap> {
     let table_index = TableIndex::from_u32(table_index);
     let elem_index = ElemIndex::from_u32(elem_index);
     let instance = (*vmctx).instance_mut();
@@ -300,7 +300,7 @@ unsafe fn memory_copy(
     src_index: u32,
     src: u64,
     len: u64,
-) -> Result<(), TrapCode> {
+) -> Result<(), Trap> {
     let src_index = MemoryIndex::from_u32(src_index);
     let dst_index = MemoryIndex::from_u32(dst_index);
     let instance = (*vmctx).instance_mut();
@@ -314,7 +314,7 @@ unsafe fn memory_fill(
     dst: u64,
     val: u32,
     len: u64,
-) -> Result<(), TrapCode> {
+) -> Result<(), Trap> {
     let memory_index = MemoryIndex::from_u32(memory_index);
     let instance = (*vmctx).instance_mut();
     instance.memory_fill(memory_index, dst, val as u8, len)
@@ -328,7 +328,7 @@ unsafe fn memory_init(
     dst: u64,
     src: u32,
     len: u32,
-) -> Result<(), TrapCode> {
+) -> Result<(), Trap> {
     let memory_index = MemoryIndex::from_u32(memory_index);
     let data_index = DataIndex::from_u32(data_index);
     let instance = (*vmctx).instance_mut();
@@ -498,14 +498,14 @@ unsafe fn validate_atomic_addr(
     addr: u64,
     access_size: u64,
     access_alignment: u64,
-) -> Result<(), TrapCode> {
+) -> Result<(), Trap> {
     debug_assert!(access_alignment.is_power_of_two());
-    ensure!(addr % access_alignment == 0, TrapCode::HeapMisaligned);
+    ensure!(addr % access_alignment == 0, Trap::HeapMisaligned);
 
     let length = u64::try_from(instance.get_memory(memory).current_length()).unwrap();
     ensure!(
         addr.saturating_add(access_size) < length,
-        TrapCode::HeapOutOfBounds
+        Trap::MemoryOutOfBounds
     );
 
     Ok(())

crates/runtime/src/table.rs

@@ -8,7 +8,7 @@ use anyhow::{bail, format_err, Error, Result};
 use std::convert::{TryFrom, TryInto};
 use std::ops::Range;
 use std::ptr;
-use wasmtime_environ::{TablePlan, TrapCode, WasmType, FUNCREF_INIT_BIT, FUNCREF_MASK};
+use wasmtime_environ::{TablePlan, Trap, WasmType, FUNCREF_INIT_BIT, FUNCREF_MASK};
 
 /// An element going into or coming out of a table.
 ///
@@ -267,7 +267,7 @@ impl Table {
         &mut self,
         dst: u32,
         items: impl ExactSizeIterator<Item = *mut VMCallerCheckedAnyfunc>,
-    ) -> Result<(), TrapCode> {
+    ) -> Result<(), Trap> {
         assert!(self.element_type() == TableElementType::Func);
 
         let elements = match self
@@ -276,7 +276,7 @@ impl Table {
             .and_then(|s| s.get_mut(..items.len()))
         {
             Some(elements) => elements,
-            None => return Err(TrapCode::TableOutOfBounds),
+            None => return Err(Trap::TableOutOfBounds),
         };
 
         for (item, slot) in items.zip(elements) {
@@ -290,14 +290,14 @@ impl Table {
     /// Fill `table[dst..dst + len]` with `val`.
     ///
     /// Returns a trap error on out-of-bounds accesses.
-    pub fn fill(&mut self, dst: u32, val: TableElement, len: u32) -> Result<(), TrapCode> {
+    pub fn fill(&mut self, dst: u32, val: TableElement, len: u32) -> Result<(), Trap> {
         let start = dst as usize;
         let end = start
             .checked_add(len as usize)
-            .ok_or_else(|| TrapCode::TableOutOfBounds)?;
+            .ok_or_else(|| Trap::TableOutOfBounds)?;
 
         if end > self.size() as usize {
-            return Err(TrapCode::TableOutOfBounds);
+            return Err(Trap::TableOutOfBounds);
         }
 
         debug_assert!(self.type_matches(&val));
@@ -412,7 +412,7 @@ impl Table {
         dst_index: u32,
         src_index: u32,
         len: u32,
-    ) -> Result<(), TrapCode> {
+    ) -> Result<(), Trap> {
         // https://webassembly.github.io/bulk-memory-operations/core/exec/instructions.html#exec-table-copy
 
         if src_index
@@ -422,7 +422,7 @@ impl Table {
                 .checked_add(len)
                 .map_or(true, |m| m > (*dst_table).size())
         {
-            return Err(TrapCode::TableOutOfBounds);
+            return Err(Trap::TableOutOfBounds);
         }
 
         debug_assert!(

crates/runtime/src/traphandlers.rs

@@ -10,7 +10,6 @@ use std::cell::{Cell, UnsafeCell};
 use std::mem::MaybeUninit;
 use std::ptr;
 use std::sync::Once;
-use wasmtime_environ::TrapCode;
 
 pub use self::backtrace::Backtrace;
 pub use self::tls::{tls_eager_initialize, TlsRestore};
@@ -112,7 +111,7 @@ pub unsafe fn raise_user_trap(error: Error, needs_backtrace: bool) -> ! {
 /// Only safe to call when wasm code is on the stack, aka `catch_traps` must
 /// have been previously called. Additionally no Rust destructors can be on the
 /// stack. They will be skipped and not executed.
-pub unsafe fn raise_lib_trap(trap: TrapCode) -> ! {
+pub unsafe fn raise_lib_trap(trap: wasmtime_environ::Trap) -> ! {
     raise_trap(TrapReason::Wasm(trap))
 }
 
@@ -153,7 +152,7 @@ pub enum TrapReason {
     Jit(usize),
 
     /// A trap raised from a wasm libcall
-    Wasm(TrapCode),
+    Wasm(wasmtime_environ::Trap),
 }
 
 impl TrapReason {
@@ -185,8 +184,8 @@ impl From<Error> for TrapReason {
     }
 }
 
-impl From<TrapCode> for TrapReason {
+impl From<wasmtime_environ::Trap> for TrapReason {
-    fn from(code: TrapCode) -> Self {
+    fn from(code: wasmtime_environ::Trap) -> Self {
         TrapReason::Wasm(code)
     }
 }

crates/wasmtime/src/component/func/host.rs

@@ -1,7 +1,7 @@
 use crate::component::func::{Memory, MemoryMut, Options};
 use crate::component::storage::slice_to_storage_mut;
 use crate::component::{ComponentNamedList, ComponentType, Lift, Lower, Type, Val};
-use crate::{AsContextMut, StoreContextMut, Trap, ValRaw};
+use crate::{AsContextMut, StoreContextMut, ValRaw};
 use anyhow::{anyhow, bail, Context, Result};
 use std::any::Any;
 use std::mem::{self, MaybeUninit};
@@ -270,7 +270,7 @@ fn validate_inbounds<T: ComponentType>(memory: &[u8], ptr: &ValRaw) -> Result<us
 unsafe fn handle_result(func: impl FnOnce() -> Result<()>) {
     match panic::catch_unwind(AssertUnwindSafe(func)) {
         Ok(Ok(())) => {}
-        Ok(Err(e)) => Trap::raise(e),
+        Ok(Err(e)) => crate::trap::raise(e),
         Err(e) => wasmtime_runtime::resume_panic(e),
     }
 }

crates/wasmtime/src/externals.rs

@@ -2,7 +2,7 @@ use crate::store::{StoreData, StoreOpaque, Stored};
 use crate::trampoline::{generate_global_export, generate_table_export};
 use crate::{
     AsContext, AsContextMut, Engine, ExternRef, ExternType, Func, GlobalType, Memory, Mutability,
-    SharedMemory, TableType, Trap, Val, ValType,
+    SharedMemory, TableType, Val, ValType,
 };
 use anyhow::{anyhow, bail, Result};
 use std::mem;
@@ -462,9 +462,7 @@ impl Table {
         let init = init.into_table_element(store, ty.element())?;
         unsafe {
             let table = Table::from_wasmtime_table(wasmtime_export, store);
-            (*table.wasmtime_table(store, std::iter::empty()))
+            (*table.wasmtime_table(store, std::iter::empty())).fill(0, init, ty.minimum())?;
-                .fill(0, init, ty.minimum())
-                .map_err(|c| Trap::from_env(c))?;
 
             Ok(table)
         }
@@ -652,8 +650,7 @@ impl Table {
         let src_range = src_index..(src_index.checked_add(len).unwrap_or(u32::MAX));
         let src_table = src_table.wasmtime_table(store, src_range);
         unsafe {
-            runtime::Table::copy(dst_table, src_table, dst_index, src_index, len)
+            runtime::Table::copy(dst_table, src_table, dst_index, src_index, len)?;
-                .map_err(|c| Trap::from_env(c))?;
         }
         Ok(())
     }
@@ -681,9 +678,7 @@ impl Table {
 
         let table = self.wasmtime_table(store, std::iter::empty());
         unsafe {
-            (*table)
+            (*table).fill(dst, val, len)?;
-                .fill(dst, val, len)
-                .map_err(|c| Trap::from_env(c))?;
         }
 
         Ok(())

crates/wasmtime/src/func.rs

@@ -1,7 +1,7 @@
 use crate::store::{StoreData, StoreOpaque, Stored};
 use crate::{
     AsContext, AsContextMut, CallHook, Engine, Extern, FuncType, Instance, StoreContext,
-    StoreContextMut, Trap, Val, ValRaw, ValType,
+    StoreContextMut, Val, ValRaw, ValType,
 };
 use anyhow::{bail, Context as _, Error, Result};
 use std::future::Future;
@@ -343,6 +343,8 @@ impl Func {
     ///
     /// For more information about errors in Wasmtime see the [`Trap`]
     /// documentation.
+    ///
+    /// [`Trap`]: crate::Trap
     #[cfg(compiler)]
     #[cfg_attr(nightlydoc, doc(cfg(feature = "cranelift")))] // see build.rs
     pub fn new<T>(
@@ -581,6 +583,8 @@ impl Func {
     /// For more information about errors in Wasmtime see the [`Trap`]
     /// documentation.
     ///
+    /// [`Trap`]: crate::Trap
+    ///
     /// # Examples
     ///
     /// First up we can see how simple wasm imports can be implemented, such
@@ -816,6 +820,8 @@ impl Func {
     /// Errors typically indicate that execution of WebAssembly was halted
     /// mid-way and did not complete after the error condition happened.
     ///
+    /// [`Trap`]: crate::Trap
+    ///
     /// # Panics
     ///
     /// This function will panic if called on a function belonging to an async
@@ -1305,7 +1311,7 @@ pub(crate) fn invoke_wasm_and_catch_traps<T>(
         );
         exit_wasm(store, exit);
         store.0.call_hook(CallHook::ReturningFromWasm)?;
-        result.map_err(|t| Trap::from_runtime_box(store.0, t))
+        result.map_err(|t| crate::trap::from_runtime_box(store.0, t))
     }
 }
 
@@ -1947,7 +1953,7 @@ macro_rules! impl_into_func {
 
                     match result {
                         CallResult::Ok(val) => val,
-                        CallResult::Trap(err) => Trap::raise(err),
+                        CallResult::Trap(err) => crate::trap::raise(err),
                         CallResult::Panic(panic) => wasmtime_runtime::resume_panic(panic),
                     }
                 }

crates/wasmtime/src/instance.rs

@@ -3,7 +3,7 @@ use crate::store::{InstanceId, StoreOpaque, Stored};
 use crate::types::matching;
 use crate::{
     AsContextMut, Engine, Export, Extern, Func, Global, Memory, Module, SharedMemory,
-    StoreContextMut, Table, Trap, TypedFunc,
+    StoreContextMut, Table, TypedFunc,
 };
 use anyhow::{anyhow, bail, Context, Error, Result};
 use std::mem;
@@ -91,6 +91,8 @@ impl Instance {
     /// check for trap errors, you can use `error.downcast::<Trap>()`. For more
     /// about error handling see the [`Trap`] documentation.
     ///
+    /// [`Trap`]: crate::Trap
+    ///
     /// # Panics
     ///
     /// This function will panic if called with a store associated with a
@@ -325,7 +327,7 @@ impl Instance {
             )
             .map_err(|e| -> Error {
                 match e {
-                    InstantiationError::Trap(trap) => Trap::from_env(trap).into(),
+                    InstantiationError::Trap(trap) => trap.into(),
                     other => other.into(),
                 }
             })?;

crates/wasmtime/src/module/registry.rs

@@ -3,14 +3,13 @@
 use crate::code::CodeObject;
 #[cfg(feature = "component-model")]
 use crate::component::Component;
-use crate::{FrameInfo, Module};
+use crate::{FrameInfo, Module, Trap};
 use once_cell::sync::Lazy;
 use std::collections::btree_map::Entry;
 use std::{
     collections::BTreeMap,
     sync::{Arc, RwLock},
 };
-use wasmtime_environ::TrapCode;
 use wasmtime_jit::CodeMemory;
 use wasmtime_runtime::{ModuleInfo, VMCallerCheckedAnyfunc, VMTrampoline};
 
@@ -132,7 +131,7 @@ impl ModuleRegistry {
     }
 
     /// Fetches trap information about a program counter in a backtrace.
-    pub fn lookup_trap_code(&self, pc: usize) -> Option<TrapCode> {
+    pub fn lookup_trap_code(&self, pc: usize) -> Option<Trap> {
         let (code, offset) = self.code(pc)?;
         wasmtime_environ::lookup_trap_code(code.code.code_memory().trap_data(), offset)
     }

crates/wasmtime/src/trampoline/func.rs

@@ -1,6 +1,6 @@
 //! Support for a calling of an imported function.
 
-use crate::{Engine, FuncType, Trap, ValRaw};
+use crate::{Engine, FuncType, ValRaw};
 use anyhow::Result;
 use std::panic::{self, AssertUnwindSafe};
 use std::ptr::NonNull;
@@ -56,7 +56,7 @@ unsafe extern "C" fn stub_fn<F>(
         // call-site, which gets unwrapped in `Trap::from_runtime` later on as we
         // convert from the internal `Trap` type to our own `Trap` type in this
         // crate.
-        Ok(Err(trap)) => Trap::raise(trap.into()),
+        Ok(Err(trap)) => crate::trap::raise(trap.into()),
 
         // And finally if the imported function panicked, then we trigger the
         // form of unwinding that's safe to jump over wasm code on all

crates/wasmtime/src/trap.rs

@@ -2,7 +2,7 @@ use crate::store::StoreOpaque;
 use crate::Module;
 use anyhow::Error;
 use std::fmt;
-use wasmtime_environ::{EntityRef, FilePos, TrapCode};
+use wasmtime_environ::{EntityRef, FilePos};
 use wasmtime_jit::{demangle_function_name, demangle_function_name_or_index};
 
 /// Representation of a WebAssembly trap and what caused it to occur.
@@ -65,78 +65,20 @@ use wasmtime_jit::{demangle_function_name, demangle_function_name_or_index};
 /// # Ok(())
 /// # }
 /// ```
-//
+pub use wasmtime_environ::Trap;
-// The code can be accessed from the c-api, where the possible values are translated
-// into enum values defined there:
-//
-// * `wasm_trap_code` in c-api/src/trap.rs, and
-// * `wasmtime_trap_code_enum` in c-api/include/wasmtime/trap.h.
-//
-// These need to be kept in sync.
-#[non_exhaustive]
-#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
-pub enum Trap {
-    /// The current stack space was exhausted.
-    StackOverflow,
 
-    /// An out-of-bounds memory access.
+// Same safety requirements and caveats as
-    MemoryOutOfBounds,
+// `wasmtime_runtime::raise_user_trap`.
-
+pub(crate) unsafe fn raise(error: anyhow::Error) -> ! {
-    /// A wasm atomic operation was presented with a not-naturally-aligned linear-memory address.
-    HeapMisaligned,
-
-    /// An out-of-bounds access to a table.
-    TableOutOfBounds,
-
-    /// Indirect call to a null table entry.
-    IndirectCallToNull,
-
-    /// Signature mismatch on indirect call.
-    BadSignature,
-
-    /// An integer arithmetic operation caused an overflow.
-    IntegerOverflow,
-
-    /// An integer division by zero.
-    IntegerDivisionByZero,
-
-    /// Failed float-to-int conversion.
-    BadConversionToInteger,
-
-    /// Code that was supposed to have been unreachable was reached.
-    UnreachableCodeReached,
-
-    /// Execution has potentially run too long and may be interrupted.
-    Interrupt,
-
-    /// When the `component-model` feature is enabled this trap represents a
-    /// function that was `canon lift`'d, then `canon lower`'d, then called.
-    /// This combination of creation of a function in the component model
-    /// generates a function that always traps and, when called, produces this
-    /// flavor of trap.
-    AlwaysTrapAdapter,
-
-    /// When wasm code is configured to consume fuel and it runs out of fuel
-    /// then this trap will be raised.
-    ///
-    /// For more information see
-    /// [`Config::consume_fuel`](crate::Config::consume_fuel).
-    OutOfFuel,
-}
-
-impl Trap {
-    // Same safety requirements and caveats as
-    // `wasmtime_runtime::raise_user_trap`.
-    pub(crate) unsafe fn raise(error: anyhow::Error) -> ! {
     let needs_backtrace = error.downcast_ref::<WasmBacktrace>().is_none();
     wasmtime_runtime::raise_user_trap(error, needs_backtrace)
-    }
+}
 
-    #[cold] // traps are exceptional, this helps move handling off the main path
+#[cold] // traps are exceptional, this helps move handling off the main path
-    pub(crate) fn from_runtime_box(
+pub(crate) fn from_runtime_box(
     store: &StoreOpaque,
     runtime_trap: Box<wasmtime_runtime::Trap>,
-    ) -> Error {
+) -> Error {
     let wasmtime_runtime::Trap { reason, backtrace } = *runtime_trap;
     let (error, pc) = match reason {
         // For user-defined errors they're already an `anyhow::Error` so no
@@ -163,12 +105,10 @@ impl Trap {
             let code = store
                 .modules()
                 .lookup_trap_code(pc)
-                    .unwrap_or(TrapCode::StackOverflow);
+                .unwrap_or(Trap::StackOverflow);
-                (Trap::from_env(code).into(), Some(pc))
+            (code.into(), Some(pc))
-            }
-            wasmtime_runtime::TrapReason::Wasm(trap_code) => {
-                (Trap::from_env(trap_code).into(), None)
         }
+        wasmtime_runtime::TrapReason::Wasm(trap_code) => (trap_code.into(), None),
     };
     match backtrace {
         Some(bt) => {
@@ -181,52 +121,8 @@ impl Trap {
         }
         None => error,
     }
-    }
-
-    /// Panics if `code` is `TrapCode::User`.
-    pub(crate) fn from_env(code: TrapCode) -> Self {
-        match code {
-            TrapCode::StackOverflow => Trap::StackOverflow,
-            TrapCode::HeapOutOfBounds => Trap::MemoryOutOfBounds,
-            TrapCode::HeapMisaligned => Trap::HeapMisaligned,
-            TrapCode::TableOutOfBounds => Trap::TableOutOfBounds,
-            TrapCode::IndirectCallToNull => Trap::IndirectCallToNull,
-            TrapCode::BadSignature => Trap::BadSignature,
-            TrapCode::IntegerOverflow => Trap::IntegerOverflow,
-            TrapCode::IntegerDivisionByZero => Trap::IntegerDivisionByZero,
-            TrapCode::BadConversionToInteger => Trap::BadConversionToInteger,
-            TrapCode::UnreachableCodeReached => Trap::UnreachableCodeReached,
-            TrapCode::Interrupt => Trap::Interrupt,
-            TrapCode::AlwaysTrapAdapter => Trap::AlwaysTrapAdapter,
-        }
-    }
 }
 
-impl fmt::Display for Trap {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        use Trap::*;
-
-        let desc = match self {
-            StackOverflow => "call stack exhausted",
-            MemoryOutOfBounds => "out of bounds memory access",
-            HeapMisaligned => "misaligned memory access",
-            TableOutOfBounds => "undefined element: out of bounds table access",
-            IndirectCallToNull => "uninitialized element",
-            BadSignature => "indirect call type mismatch",
-            IntegerOverflow => "integer overflow",
-            IntegerDivisionByZero => "integer divide by zero",
-            BadConversionToInteger => "invalid conversion to integer",
-            UnreachableCodeReached => "wasm `unreachable` instruction executed",
-            Interrupt => "interrupt",
-            AlwaysTrapAdapter => "degenerate component adapter called",
-            OutOfFuel => "all fuel consumed by WebAssembly",
-        };
-        write!(f, "wasm trap: {desc}")
-    }
-}
-
-impl std::error::Error for Trap {}
-
 /// Representation of a backtrace of function frames in a WebAssembly module for
 /// where an error happened.
 ///