Implement core::error::Error for all error types (#1462)

* implement core::error::Error for all error types

This way we no longer have to conditionally compile for `std`.

* apply rustfmt

Author: Robbepop

crates/core/src/untyped.rs

@@ -1,7 +1,10 @@
 #[cfg(feature = "simd")]
 use crate::V128;
 use crate::{F32, F64};
-use core::fmt::{self, Display};
+use core::{
+    error::Error,
+    fmt::{self, Display},
+};
 
 /// An untyped value.
 ///
@@ -300,8 +303,7 @@ impl UntypedError {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for UntypedError {}
+impl Error for UntypedError {}
 
 impl Display for UntypedError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {

crates/ir/src/error.rs

@@ -24,5 +24,4 @@ impl fmt::Display for Error {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}

crates/wasmi/src/engine/executor/instrs/call.rs

@@ -74,8 +74,7 @@ pub struct ResumableHostError {
     caller_results: RegSpan,
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for ResumableHostError {}
+impl core::error::Error for ResumableHostError {}
 
 impl fmt::Display for ResumableHostError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

crates/wasmi/src/engine/limits/engine.rs

@@ -1,4 +1,7 @@
-use core::fmt::{self, Display};
+use core::{
+    error::Error,
+    fmt::{self, Display},
+};
 
 /// An error that can occur upon parsing or compiling a Wasm module when [`EnforcedLimits`] are set.
 #[derive(Debug, Copy, Clone)]
@@ -23,8 +26,7 @@ pub enum EnforcedLimitsError {
     MinAvgBytesPerFunction { limit: u32, avg: u32 },
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for EnforcedLimitsError {}
+impl Error for EnforcedLimitsError {}
 
 impl Display for EnforcedLimitsError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

crates/wasmi/src/engine/limits/stack.rs

@@ -1,5 +1,6 @@
 use crate::core::UntypedVal;
 use core::{
+    error::Error,
     fmt::{self, Display},
     mem::size_of,
 };
@@ -31,8 +32,7 @@ pub enum LimitsError {
     InitialValueStackExceedsMaximum,
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for LimitsError {}
+impl Error for LimitsError {}
 
 impl Display for LimitsError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

crates/wasmi/src/engine/translator/error.rs

@@ -1,4 +1,7 @@
-use core::fmt::{self, Display};
+use core::{
+    error::Error,
+    fmt::{self, Display},
+};
 
 /// An error that may occur upon parsing, validating and translating Wasm.
 #[derive(Debug)]
@@ -43,8 +46,7 @@ impl TranslationError {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for TranslationError {}
+impl Error for TranslationError {}
 
 impl Display for TranslationError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

crates/wasmi/src/engine/translator/labels.rs

@@ -61,8 +61,7 @@ pub enum LabelError {
     Unpinned { label: LabelRef },
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for LabelError {}
+impl core::error::Error for LabelError {}
 
 impl Display for LabelError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

crates/wasmi/src/error.rs

@@ -141,8 +141,7 @@ impl Error {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
+impl core::error::Error for Error {}
 
 impl Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
@@ -242,8 +241,7 @@ impl ErrorKind {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for ErrorKind {}
+impl core::error::Error for ErrorKind {}
 
 impl Display for ErrorKind {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {

crates/wasmi/src/func/error.rs

@@ -1,5 +1,8 @@
 use crate::core::FuncTypeError as CoreFuncTypeError;
-use core::{fmt, fmt::Display};
+use core::{
+    error::Error,
+    fmt::{self, Display},
+};
 
 /// Errors that can occur upon type checking function signatures.
 #[derive(Debug)]
@@ -28,8 +31,7 @@ impl From<CoreFuncTypeError> for FuncError {
     }
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for FuncError {}
+impl Error for FuncError {}
 
 impl Display for FuncError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {

crates/wasmi/src/global.rs

@@ -5,7 +5,11 @@ use crate::{
     value::WithType,
     Val,
 };
-use core::{fmt, fmt::Display, ptr::NonNull};
+use core::{
+    error::Error,
+    fmt::{self, Display},
+    ptr::NonNull,
+};
 
 /// A raw index to a global variable entity.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
@@ -46,8 +50,7 @@ pub enum GlobalError {
     },
 }
 
-#[cfg(feature = "std")]
-impl std::error::Error for GlobalError {}
+impl Error for GlobalError {}
 
 impl Display for GlobalError {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {