remove duplicated code, wrap WasmPtr on wasi side

This commit is contained in:
Mark McCaskey
2019-06-11 11:10:42 +02:00
parent 7965ed2746
commit b36783fc50
5 changed files with 72 additions and 110 deletions

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@ -42,7 +42,6 @@ mod lock;
mod math;
mod memory;
mod process;
mod ptr;
mod signal;
mod storage;
mod syscalls;

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@ -1,120 +0,0 @@
use std::{cell::Cell, fmt, marker::PhantomData, mem};
use wasmer_runtime_core::{
memory::Memory,
types::{ValueType, WasmExternType},
};
pub struct Array;
pub struct Item;
// TODO: before shipping, refactor this and the wasi code into a common crate
// and wrap it when used in the context of wasi to return the proper error codes
#[repr(transparent)]
pub struct WasmPtr<T: Copy, Ty = Item> {
offset: u32,
_phantom: PhantomData<(T, Ty)>,
}
impl<T: Copy, Ty> WasmPtr<T, Ty> {
#[inline]
pub fn new(offset: u32) -> Self {
Self {
offset,
_phantom: PhantomData,
}
}
#[inline]
pub fn offset(self) -> i32 {
self.offset as i32
}
}
#[inline(always)]
fn align_pointer(ptr: usize, align: usize) -> usize {
// clears bits below aligment amount (assumes power of 2) to align pointer
debug_assert!(align.count_ones() == 1);
ptr & !(align - 1)
}
impl<T: Copy + ValueType> WasmPtr<T, Item> {
#[inline]
pub fn deref<'a>(self, memory: &'a Memory) -> Option<&'a Cell<T>> {
if (self.offset as usize) + mem::size_of::<T>() >= memory.size().bytes().0 {
return None;
}
unsafe {
let cell_ptr = align_pointer(
memory.view::<u8>().as_ptr().add(self.offset as usize) as usize,
mem::align_of::<T>(),
) as *const Cell<T>;
Some(&*cell_ptr)
}
}
}
impl<T: Copy + ValueType> WasmPtr<T, Array> {
#[inline]
pub fn deref<'a>(self, memory: &'a Memory, index: u32, length: u32) -> Option<&'a [Cell<T>]> {
// gets the size of the item in the array with padding added such that
// for any index, we will always result an aligned memory access
let item_size = mem::size_of::<T>() + (mem::size_of::<T>() % mem::align_of::<T>());
let slice_full_len = index as usize + length as usize;
if (self.offset as usize) + (item_size * slice_full_len) >= memory.size().bytes().0 {
return None;
}
unsafe {
let cell_ptr = align_pointer(
memory.view::<u8>().as_ptr().add(self.offset as usize) as usize,
mem::align_of::<T>(),
) as *const Cell<T>;
let cell_ptrs = &std::slice::from_raw_parts(cell_ptr, slice_full_len)
[index as usize..slice_full_len as usize];
Some(cell_ptrs)
}
}
}
unsafe impl<T: Copy, Ty> WasmExternType for WasmPtr<T, Ty> {
type Native = i32;
fn to_native(self) -> Self::Native {
self.offset as i32
}
fn from_native(n: Self::Native) -> Self {
Self {
offset: n as u32,
_phantom: PhantomData,
}
}
}
unsafe impl<T: Copy, Ty> ValueType for WasmPtr<T, Ty> {}
impl<T: Copy, Ty> Clone for WasmPtr<T, Ty> {
fn clone(&self) -> Self {
Self {
offset: self.offset,
_phantom: PhantomData,
}
}
}
impl<T: Copy, Ty> Copy for WasmPtr<T, Ty> {}
impl<T: Copy, Ty> PartialEq for WasmPtr<T, Ty> {
fn eq(&self, other: &Self) -> bool {
self.offset == other.offset
}
}
impl<T: Copy, Ty> Eq for WasmPtr<T, Ty> {}
impl<T: Copy, Ty> fmt::Debug for WasmPtr<T, Ty> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "WasmPtr({:#x})", self.offset)
}
}

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@ -10,7 +10,6 @@ pub use self::unix::*;
#[cfg(windows)]
pub use self::windows::*;
use crate::ptr::{Array, WasmPtr};
use crate::utils::{copy_stat_into_wasm, get_cstr_path, get_current_directory};
use super::varargs::VarArgs;
@ -42,7 +41,10 @@ use libc::{
write,
// readlink,
};
use wasmer_runtime_core::vm::Ctx;
use wasmer_runtime_core::{
memory::ptr::{Array, WasmPtr},
vm::Ctx,
};
use super::env;
use std::cell::Cell;
@ -282,7 +284,7 @@ pub fn ___syscall183(ctx: &mut Ctx, _which: c_int, mut varargs: VarArgs) -> i32
buf_writer[i].set(byte as i8);
}
buf_writer[len].set(0);
buf_offset.offset()
buf_offset.offset() as i32
}
// mmap2