Merge #379

379: Fix small return types. r=syrusakbary a=lachlansneff This fixes returning integers smaller than 32bits from imported functions. Also some work on fixing returning errors from functions. Co-authored-by: Lachlan Sneff <[email protected]> Co-authored-by: Syrus <[email protected]>
wasmerio · Apr 22, 2019 · a42b7d3 · a42b7d3
2 parents 6478500 + 3729c4a
commit a42b7d3
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Showing 11 changed files with 256 additions and 213 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -5,6 +5,7 @@ All PRs to the Wasmer repository must add to this file.
 Blocks of changes will separated by version increments.
 
 ## **[Unreleased]**
+- [#379](https://github.com/wasmerio/wasmer/pull/379) Fix small return types from imported functions.
 - [#371](https://github.com/wasmerio/wasmer/pull/371) Add more Debug impl for WASI types
 - [#368](https://github.com/wasmerio/wasmer/pull/368) Fix issue with write buffering
 - [#343](https://github.com/wasmerio/wasmer/pull/343) Implement preopened files for WASI and fix aligment issue when accessing WASI memory

diff --git a/lib/clif-backend/src/signal/unix.rs b/lib/clif-backend/src/signal/unix.rs
@@ -76,7 +76,7 @@ pub fn call_protected<T>(handler_data: &HandlerData, f: impl FnOnce() -> T) -> R
             *jmp_buf = prev_jmp_buf;
 
             if let Some(data) = super::TRAP_EARLY_DATA.with(|cell| cell.replace(None)) {
-                Err(RuntimeError::Panic { data })
+                Err(RuntimeError::Error { data })
             } else {
                 let (faulting_addr, inst_ptr) = CAUGHT_ADDRESSES.with(|cell| cell.get());
 

diff --git a/lib/emscripten/src/varargs.rs b/lib/emscripten/src/varargs.rs
@@ -1,8 +1,5 @@
 use std::mem;
-use wasmer_runtime_core::{
-    types::{Type, WasmExternType},
-    vm::Ctx,
-};
+use wasmer_runtime_core::{types::WasmExternType, vm::Ctx};
 
 #[repr(transparent)]
 #[derive(Copy, Clone)]
@@ -19,12 +16,12 @@ impl VarArgs {
 }
 
 unsafe impl WasmExternType for VarArgs {
-    const TYPE: Type = Type::I32;
+    type Native = i32;
 
-    fn to_bits(self) -> u64 {
-        self.pointer as u64
+    fn to_native(self) -> Self::Native {
+        self.pointer as _
     }
-    fn from_bits(n: u64) -> Self {
+    fn from_native(n: Self::Native) -> Self {
         Self { pointer: n as u32 }
     }
 }
diff --git a/lib/runtime-core/src/error.rs b/lib/runtime-core/src/error.rs
@@ -1,4 +1,4 @@
-use crate::types::{FuncSig, GlobalDescriptor, MemoryDescriptor, TableDescriptor, Type, Value};
+use crate::types::{FuncSig, GlobalDescriptor, MemoryDescriptor, TableDescriptor, Type};
 use core::borrow::Borrow;
 use std::any::Any;
 
@@ -121,8 +121,7 @@ impl std::error::Error for LinkError {}
 /// Comparing two `RuntimeError`s always evaluates to false.
 pub enum RuntimeError {
     Trap { msg: Box<str> },
-    Exception { data: Box<[Value]> },
-    Panic { data: Box<dyn Any> },
+    Error { data: Box<dyn Any> },
 }
 
 impl PartialEq for RuntimeError {
@@ -137,10 +136,7 @@ impl std::fmt::Display for RuntimeError {
             RuntimeError::Trap { ref msg } => {
                 write!(f, "WebAssembly trap occured during runtime: {}", msg)
             }
-            RuntimeError::Exception { ref data } => {
-                write!(f, "Uncaught WebAssembly exception: {:?}", data)
-            }
-            RuntimeError::Panic { data } => {
+            RuntimeError::Error { data } => {
                 let msg = if let Some(s) = data.downcast_ref::<String>() {
                     s
                 } else if let Some(s) = data.downcast_ref::<&str>() {

diff --git a/lib/runtime-core/src/typed_func.rs b/lib/runtime-core/src/typed_func.rs
@@ -2,11 +2,12 @@ use crate::{
     error::RuntimeError,
     export::{Context, Export, FuncPointer},
     import::IsExport,
-    types::{FuncSig, Type, WasmExternType},
+    types::{FuncSig, NativeWasmType, Type, WasmExternType},
     vm::{self, Ctx},
 };
 use std::{
     any::Any,
+    convert::Infallible,
     ffi::c_void,
     fmt,
     marker::PhantomData,
@@ -120,25 +121,28 @@ pub trait TrapEarly<Rets>
 where
     Rets: WasmTypeList,
 {
-    fn report(self) -> Result<Rets, Box<dyn Any>>;
+    type Error: 'static;
+    fn report(self) -> Result<Rets, Self::Error>;
 }
 
 impl<Rets> TrapEarly<Rets> for Rets
 where
     Rets: WasmTypeList,
 {
-    fn report(self) -> Result<Rets, Box<dyn Any>> {
+    type Error = Infallible;
+    fn report(self) -> Result<Rets, Infallible> {
         Ok(self)
     }
 }
 
 impl<Rets, E> TrapEarly<Rets> for Result<Rets, E>
 where
     Rets: WasmTypeList,
-    E: Any,
+    E: 'static,
 {
-    fn report(self) -> Result<Rets, Box<dyn Any>> {
-        self.map_err(|err| Box::new(err) as Box<dyn Any>)
+    type Error = E;
+    fn report(self) -> Result<Rets, E> {
+        self
     }
 }
 
@@ -213,22 +217,24 @@ impl<A: WasmExternType> WasmTypeList for (A,) {
     type CStruct = S1<A>;
     type RetArray = [u64; 1];
     fn from_ret_array(array: Self::RetArray) -> Self {
-        (WasmExternType::from_bits(array[0]),)
+        (WasmExternType::from_native(NativeWasmType::from_bits(
+            array[0],
+        )),)
     }
     fn empty_ret_array() -> Self::RetArray {
         [0u64]
     }
     fn from_c_struct(c_struct: Self::CStruct) -> Self {
         let S1(a) = c_struct;
-        (a,)
+        (WasmExternType::from_native(a),)
     }
     fn into_c_struct(self) -> Self::CStruct {
         #[allow(unused_parens, non_snake_case)]
         let (a,) = self;
-        S1(a)
+        S1(WasmExternType::to_native(a))
     }
     fn types() -> &'static [Type] {
-        &[A::TYPE]
+        &[A::Native::TYPE]
     }
     #[allow(non_snake_case)]
     unsafe fn call<Rets: WasmTypeList>(
@@ -237,11 +243,8 @@ impl<A: WasmExternType> WasmTypeList for (A,) {
         wasm: Wasm,
         ctx: *mut Ctx,
     ) -> Result<Rets, WasmTrapInfo> {
-        // type Trampoline = extern "C" fn(*mut Ctx, *const c_void, *const u64, *mut u64);
-        // type Invoke = extern "C" fn(Trampoline, *mut Ctx, *const c_void, *const u64, *mut u64, &mut WasmTrapInfo) -> bool;
-
         let (a,) = self;
-        let args = [a.to_bits()];
+        let args = [a.to_native().to_bits()];
         let mut rets = Rets::empty_ret_array();
         let mut trap = WasmTrapInfo::Unknown;
 
@@ -277,40 +280,37 @@ where
 macro_rules! impl_traits {
     ( [$repr:ident] $struct_name:ident, $( $x:ident ),* ) => {
         #[repr($repr)]
-        pub struct $struct_name <$( $x ),*> ( $( $x ),* );
+        pub struct $struct_name <$( $x: WasmExternType ),*> ( $( <$x as WasmExternType>::Native ),* );
 
         impl< $( $x: WasmExternType, )* > WasmTypeList for ( $( $x ),* ) {
             type CStruct = $struct_name<$( $x ),*>;
             type RetArray = [u64; count_idents!( $( $x ),* )];
             fn from_ret_array(array: Self::RetArray) -> Self {
                 #[allow(non_snake_case)]
                 let [ $( $x ),* ] = array;
-                ( $( WasmExternType::from_bits($x) ),* )
+                ( $( WasmExternType::from_native(NativeWasmType::from_bits($x)) ),* )
             }
             fn empty_ret_array() -> Self::RetArray {
                 [0; count_idents!( $( $x ),* )]
             }
             fn from_c_struct(c_struct: Self::CStruct) -> Self {
                 #[allow(non_snake_case)]
                 let $struct_name ( $( $x ),* ) = c_struct;
-                ( $( $x ),* )
+                ( $( WasmExternType::from_native($x) ),* )
             }
             fn into_c_struct(self) -> Self::CStruct {
                 #[allow(unused_parens, non_snake_case)]
                 let ( $( $x ),* ) = self;
-                $struct_name ( $( $x ),* )
+                $struct_name ( $( WasmExternType::to_native($x) ),* )
             }
             fn types() -> &'static [Type] {
-                &[$( $x::TYPE, )*]
+                &[$( $x::Native::TYPE, )*]
             }
             #[allow(non_snake_case)]
             unsafe fn call<Rets: WasmTypeList>(self, f: NonNull<vm::Func>, wasm: Wasm, ctx: *mut Ctx) -> Result<Rets, WasmTrapInfo> {
-                // type Trampoline = extern "C" fn(*mut Ctx, *const c_void, *const u64, *mut u64);
-                // type Invoke = extern "C" fn(Trampoline, *mut Ctx, *const c_void, *const u64, *mut u64, &mut WasmTrapInfo) -> bool;
-
                 #[allow(unused_parens)]
                 let ( $( $x ),* ) = self;
-                let args = [ $( $x.to_bits() ),* ];
+                let args = [ $( $x.to_native().to_bits() ),* ];
                 let mut rets = Rets::empty_ret_array();
                 let mut trap = WasmTrapInfo::Unknown;
 
@@ -319,12 +319,6 @@ macro_rules! impl_traits {
                 } else {
                     Err(trap)
                 }
-
-                // let f: extern fn(*mut Ctx $( ,$x )*) -> Rets::CStruct = mem::transmute(f);
-                // #[allow(unused_parens)]
-                // let ( $( $x ),* ) = self;
-                // let c_struct = f(ctx $( ,$x )*);
-                // Rets::from_c_struct(c_struct)
             }
         }
 
@@ -335,15 +329,17 @@ macro_rules! impl_traits {
 
                 /// This is required for the llvm backend to be able to unwind through this function.
                 #[cfg_attr(nightly, unwind(allowed))]
-                extern fn wrap<$( $x: WasmExternType, )* Rets: WasmTypeList, Trap: TrapEarly<Rets>, FN: Fn( &mut Ctx $( ,$x )* ) -> Trap>( ctx: &mut Ctx $( ,$x: $x )* ) -> Rets::CStruct {
+                extern fn wrap<$( $x: WasmExternType, )* Rets: WasmTypeList, Trap: TrapEarly<Rets>, FN: Fn( &mut Ctx $( ,$x )* ) -> Trap>( ctx: &mut Ctx $( ,$x: <$x as WasmExternType>::Native )* ) -> Rets::CStruct {
                     let f: FN = unsafe { mem::transmute_copy(&()) };
 
                     let err = match panic::catch_unwind(panic::AssertUnwindSafe(|| {
-                        let res = f( ctx $( ,$x )* ).report();
-                        res
+                        f( ctx $( ,WasmExternType::from_native($x) )* ).report()
                     })) {
                         Ok(Ok(returns)) => return returns.into_c_struct(),
-                        Ok(Err(err)) => err,
+                        Ok(Err(err)) => {
+                            let b: Box<_> = err.into();
+                            b as Box<dyn Any>
+                        },
                         Err(err) => err,
                     };