diff options
Diffstat (limited to 'crates')
| -rw-r--r-- | crates/tinywasm/src/instance.rs | 4 | ||||
| -rw-r--r-- | crates/tinywasm/src/reference.rs | 128 | ||||
| -rw-r--r-- | crates/tinywasm/src/runtime/interpreter/macros.rs | 2 | ||||
| -rw-r--r-- | crates/tinywasm/src/store.rs | 61 |
4 files changed, 181 insertions, 14 deletions
diff --git a/crates/tinywasm/src/instance.rs b/crates/tinywasm/src/instance.rs index 5346ac3..35b54d6 100644 --- a/crates/tinywasm/src/instance.rs +++ b/crates/tinywasm/src/instance.rs @@ -199,14 +199,14 @@ impl ModuleInstance { pub fn memory(&self, store: &Store, addr: MemAddr) -> Result<MemoryRef> { let addr = self.resolve_mem_addr(addr); let mem = store.get_mem(addr as usize)?; - Ok(MemoryRef { _instance: mem.clone() }) + Ok(MemoryRef { instance: mem.clone() }) } /// Get the start function of the module /// /// Returns None if the module has no start function /// If no start function is specified, also checks for a _start function in the exports - /// (which is not part of the spec, but used by llvm) + /// (which is not part of the spec, but used by some compilers) /// /// See <https://webassembly.github.io/spec/core/syntax/modules.html#start-function> pub fn start_func(&self, store: &Store) -> Result<Option<FuncHandle>> { diff --git a/crates/tinywasm/src/reference.rs b/crates/tinywasm/src/reference.rs index bc02338..fdaae18 100644 --- a/crates/tinywasm/src/reference.rs +++ b/crates/tinywasm/src/reference.rs @@ -1,17 +1,135 @@ -use core::cell::RefCell; +use core::{ + cell::{Ref, RefCell}, + ffi::CStr, +}; + +use crate::{GlobalInstance, MemoryInstance, Result}; +use alloc::{ + ffi::CString, + rc::Rc, + string::{String, ToString}, + vec::Vec, +}; +use tinywasm_types::WasmValue; -use crate::{GlobalInstance, MemoryInstance}; -use alloc::rc::Rc; // This module essentially contains the public APIs to interact with the data stored in the store /// A reference to a memory instance #[derive(Debug, Clone)] pub struct MemoryRef { - pub(crate) _instance: Rc<RefCell<MemoryInstance>>, + pub(crate) instance: Rc<RefCell<MemoryInstance>>, +} + +/// A borrowed reference to a memory instance +#[derive(Debug)] +pub struct BorrowedMemory<'a> { + pub(crate) instance: Ref<'a, MemoryInstance>, +} + +impl<'a> BorrowedMemory<'a> { + /// Load a slice of memory + pub fn load(&self, offset: usize, len: usize) -> Result<&[u8]> { + self.instance.load(offset, 0, len) + } + + /// Load a C-style string from memory + pub fn load_cstr(&self, offset: usize, len: usize) -> Result<&CStr> { + let bytes = self.load(offset, len)?; + CStr::from_bytes_with_nul(bytes).map_err(|_| crate::Error::Other("Invalid C-style string".to_string())) + } + + /// Load a C-style string from memory, stopping at the first nul byte + pub fn load_cstr_until_nul(&self, offset: usize, max_len: usize) -> Result<&CStr> { + let bytes = self.load(offset, max_len)?; + CStr::from_bytes_until_nul(bytes).map_err(|_| crate::Error::Other("Invalid C-style string".to_string())) + } +} + +impl MemoryRef { + /// Borrow the memory instance + /// + /// This is useful for when you want to load only a reference to a slice of memory + /// without copying the data. The borrow should be dropped before any other memory + /// operations are performed. + pub fn borrow(&self) -> BorrowedMemory<'_> { + BorrowedMemory { instance: self.instance.borrow() } + } + + /// Load a slice of memory + pub fn load_vec(&self, offset: usize, len: usize) -> Result<Vec<u8>> { + self.instance.borrow().load(offset, 0, len).map(|x| x.to_vec()) + } + + /// Grow the memory by the given number of pages + pub fn grow(&self, delta_pages: i32) -> Option<i32> { + self.instance.borrow_mut().grow(delta_pages) + } + + /// Get the current size of the memory in pages + pub fn page_count(&self) -> usize { + self.instance.borrow().page_count() + } + + /// Copy a slice of memory to another place in memory + pub fn copy_within(&self, src: usize, dst: usize, len: usize) -> Result<()> { + self.instance.borrow_mut().copy_within(src, dst, len) + } + + /// Fill a slice of memory with a value + pub fn fill(&self, offset: usize, len: usize, val: u8) -> Result<()> { + self.instance.borrow_mut().fill(offset, len, val) + } + + /// Load a UTF-8 string from memory + pub fn load_string(&self, offset: usize, len: usize) -> Result<String> { + let bytes = self.load_vec(offset, len)?; + Ok(String::from_utf8(bytes).map_err(|_| crate::Error::Other("Invalid UTF-8 string".to_string()))?) + } + + /// Load a C-style string from memory + pub fn load_cstring(&self, offset: usize, len: usize) -> Result<CString> { + Ok(CString::from(self.borrow().load_cstr(offset, len)?)) + } + + /// Load a C-style string from memory, stopping at the first nul byte + pub fn load_cstring_until_nul(&self, offset: usize, max_len: usize) -> Result<CString> { + Ok(CString::from(self.borrow().load_cstr_until_nul(offset, max_len)?)) + } + + /// Load a JavaScript-style utf-16 string from memory + pub fn load_js_string(&self, offset: usize, len: usize) -> Result<String> { + let memref = self.borrow(); + let bytes = memref.load(offset, len)?; + let mut string = String::new(); + for i in 0..(len / 2) { + let c = u16::from_le_bytes([bytes[i * 2], bytes[i * 2 + 1]]); + string.push( + char::from_u32(c as u32).ok_or_else(|| crate::Error::Other("Invalid UTF-16 string".to_string()))?, + ); + } + Ok(string) + } + + /// Store a slice of memory + pub fn store(&self, offset: usize, len: usize, data: &[u8]) -> Result<()> { + self.instance.borrow_mut().store(offset, 0, data, len) + } } /// A reference to a global instance #[derive(Debug, Clone)] pub struct GlobalRef { - pub(crate) _instance: Rc<RefCell<GlobalInstance>>, + pub(crate) instance: Rc<RefCell<GlobalInstance>>, +} + +impl GlobalRef { + /// Get the value of the global + pub fn get(&self) -> WasmValue { + self.instance.borrow().get() + } + + /// Set the value of the global + pub fn set(&self, val: WasmValue) -> Result<()> { + self.instance.borrow_mut().set(val) + } } diff --git a/crates/tinywasm/src/runtime/interpreter/macros.rs b/crates/tinywasm/src/runtime/interpreter/macros.rs index 909acb3..cc65812 100644 --- a/crates/tinywasm/src/runtime/interpreter/macros.rs +++ b/crates/tinywasm/src/runtime/interpreter/macros.rs @@ -63,7 +63,7 @@ macro_rules! mem_store { let val = val as $store_type; let val = val.to_le_bytes(); - mem.borrow_mut().store(($arg.offset + addr) as usize, $arg.align as usize, &val)?; + mem.borrow_mut().store(($arg.offset + addr) as usize, $arg.align as usize, &val, val.len())?; }}; } diff --git a/crates/tinywasm/src/store.rs b/crates/tinywasm/src/store.rs index d281b5c..1c0d260 100644 --- a/crates/tinywasm/src/store.rs +++ b/crates/tinywasm/src/store.rs @@ -306,7 +306,9 @@ impl Store { })?; // See comment for active element sections in the function above why we need to do this here - if let Err(Error::Trap(trap)) = mem.borrow_mut().store(offset as usize, 0, &data.data) { + if let Err(Error::Trap(trap)) = + mem.borrow_mut().store(offset as usize, 0, &data.data, data.data.len()) + { return Ok((data_addrs.into_boxed_slice(), Some(trap))); } @@ -607,8 +609,8 @@ impl MemoryInstance { } } - pub(crate) fn store(&mut self, addr: usize, _align: usize, data: &[u8]) -> Result<()> { - let end = addr.checked_add(data.len()).ok_or_else(|| { + pub(crate) fn store(&mut self, addr: usize, _align: usize, data: &[u8], len: usize) -> Result<()> { + let end = addr.checked_add(len).ok_or_else(|| { Error::Trap(crate::Trap::MemoryOutOfBounds { offset: addr, len: data.len(), max: self.data.len() }) })?; @@ -646,9 +648,37 @@ impl MemoryInstance { self.page_count } - pub(crate) fn grow(&mut self, delta: i32) -> Option<i32> { + pub(crate) fn fill(&mut self, addr: usize, len: usize, val: u8) -> Result<()> { + let end = addr + .checked_add(len) + .ok_or_else(|| Error::Trap(crate::Trap::MemoryOutOfBounds { offset: addr, len, max: self.data.len() }))?; + if end > self.data.len() { + return Err(Error::Trap(crate::Trap::MemoryOutOfBounds { offset: addr, len, max: self.data.len() })); + } + self.data[addr..end].fill(val); + Ok(()) + } + + pub(crate) fn copy_within(&mut self, dst: usize, src: usize, len: usize) -> Result<()> { + let end = src + .checked_add(len) + .ok_or_else(|| Error::Trap(crate::Trap::MemoryOutOfBounds { offset: src, len, max: self.data.len() }))?; + if end > self.data.len() || end < src { + return Err(Error::Trap(crate::Trap::MemoryOutOfBounds { offset: src, len, max: self.data.len() })); + } + let end = dst + .checked_add(len) + .ok_or_else(|| Error::Trap(crate::Trap::MemoryOutOfBounds { offset: dst, len, max: self.data.len() }))?; + if end > self.data.len() || end < dst { + return Err(Error::Trap(crate::Trap::MemoryOutOfBounds { offset: dst, len, max: self.data.len() })); + } + self.data[dst..end].copy_within(src..end, len); + Ok(()) + } + + pub(crate) fn grow(&mut self, pages_delta: i32) -> Option<i32> { let current_pages = self.page_count(); - let new_pages = current_pages as i64 + delta as i64; + let new_pages = current_pages as i64 + pages_delta as i64; if new_pages < 0 || new_pages > MAX_PAGES as i64 { return None; @@ -669,7 +699,7 @@ impl MemoryInstance { self.page_count = new_pages as usize; log::debug!("memory was {} pages", current_pages); - log::debug!("memory grown by {} pages", delta); + log::debug!("memory grown by {} pages", pages_delta); log::debug!("memory grown to {} pages", self.page_count); Some(current_pages.try_into().expect("memory size out of bounds, this should have been caught earlier")) @@ -690,6 +720,25 @@ impl GlobalInstance { pub(crate) fn new(ty: GlobalType, value: RawWasmValue, owner: ModuleInstanceAddr) -> Self { Self { ty, value, _owner: owner } } + + pub(crate) fn get(&self) -> WasmValue { + self.value.attach_type(self.ty.ty) + } + + pub(crate) fn set(&mut self, val: WasmValue) -> Result<()> { + if val.val_type() != self.ty.ty { + return Err(Error::Other(format!( + "global type mismatch: expected {:?}, got {:?}", + self.ty.ty, + val.val_type() + ))); + } + if !self.ty.mutable { + return Err(Error::Other("global is immutable".to_string())); + } + self.value = val.into(); + Ok(()) + } } /// A WebAssembly Element Instance |