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feat: Wasm data section parsing
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greenhat committed Sep 17, 2023
1 parent f26599b commit c1119e7
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Showing 8 changed files with 471 additions and 12 deletions.
29 changes: 29 additions & 0 deletions Cargo.lock

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1 change: 1 addition & 0 deletions frontend-wasm/Cargo.toml
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@ log.workspace = true
anyhow.workspace = true
wasmparser = "0.107"
itertools = "0.11"
derive_more = "0.99"

[dev-dependencies]
wat = "1.0.69"
Expand Down
46 changes: 44 additions & 2 deletions frontend-wasm/src/environ/module_env.rs
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,8 @@ use crate::error::{WasmError, WasmResult};
use crate::func_translator::FuncTranslator;
use crate::translation_utils::sig_from_funct_type;
use crate::wasm_types::{
DefinedFuncIndex, FuncIndex, Global, GlobalIndex, Memory, MemoryIndex, TypeIndex,
DataSegment, DataSegmentIndex, DefinedFuncIndex, FuncIndex, Global, GlobalIndex, Memory,
MemoryIndex, TypeIndex,
};
use miden_diagnostics::{DiagnosticsHandler, SourceSpan};
use miden_hir::cranelift_entity::{EntityRef, PrimaryMap, SecondaryMap};
Expand Down Expand Up @@ -43,6 +44,12 @@ pub struct ModuleInfo {
/// Global names.
global_names: SecondaryMap<GlobalIndex, String>,

/// Data segments declared in the module.
pub data_segments: PrimaryMap<DataSegmentIndex, DataSegment>,

/// Data segment names.
pub data_segment_names: SecondaryMap<DataSegmentIndex, String>,

/// The start function.
pub start_func: Option<FuncIndex>,
}
Expand All @@ -59,6 +66,8 @@ impl ModuleInfo {
globals: PrimaryMap::new(),
function_names: SecondaryMap::new(),
global_names: SecondaryMap::new(),
data_segments: PrimaryMap::new(),
data_segment_names: SecondaryMap::new(),
}
}

Expand Down Expand Up @@ -120,6 +129,7 @@ impl<'a> ModuleEnvironment<'a> {
) -> WasmResult<Module> {
let mut module_builder = ModuleBuilder::new(self.info.name.as_str());
self.build_globals(&mut module_builder, diagnostics)?;
self.build_data_segments(&mut module_builder, diagnostics)?;
let get_num_func_imports = self.get_num_func_imports();
for (def_func_index, body) in &self.function_bodies {
let func_index = FuncIndex::new(get_num_func_imports + def_func_index.index());
Expand Down Expand Up @@ -152,7 +162,7 @@ impl<'a> ModuleEnvironment<'a> {
}

fn build_globals(
&mut self,
&self,
module_builder: &mut ModuleBuilder,
diagnostics: &DiagnosticsHandler,
) -> Result<(), WasmError> {
Expand All @@ -178,6 +188,30 @@ impl<'a> ModuleEnvironment<'a> {
})
}

fn build_data_segments(
&self,
_module_builder: &mut ModuleBuilder,
diagnostics: &DiagnosticsHandler,
) -> Result<(), WasmError> {
for (data_segment_idx, data_segment) in &self.info.data_segments {
let data_segment_name = self.info.data_segment_names[data_segment_idx].clone();
let _readonly = data_segment_name.contains(".rodata");
let _init = ConstantData::from(data_segment.data.clone());
let _offset = data_segment
.offset
.as_i32(&self.info.globals, diagnostics)?;
// if let Err(e) = module_builder.declare_data_segment(offset, size, init, readonly) {
// let message = format!("Failed to declare data segment {init} for data segment size {size} at {offset} with error: {:?}", e);
// diagnostics
// .diagnostic(miden_diagnostics::Severity::Error)
// .with_message(message.clone())
// .emit();
// return Err(WasmError::Unexpected(message));
// }
}
Ok(())
}

/// Declares a function signature to the environment.
pub fn declare_type_func(&mut self, func_type: FunctionType) {
self.info.func_types.push(func_type);
Expand Down Expand Up @@ -237,6 +271,14 @@ impl<'a> ModuleEnvironment<'a> {
self.info.function_names[func_index] = String::from(name);
}

pub fn declare_data_segment(&mut self, segment: DataSegment) {
self.info.data_segments.push(segment);
}

pub fn declare_data_segment_name(&mut self, segment_index: DataSegmentIndex, name: &'a str) {
self.info.data_segment_names[segment_index] = String::from(name);
}

/// Indicates that a custom section has been found in the wasm file
pub fn custom_section(&mut self, _name: &'a str, _data: &'a [u8]) {
// Do we need to support custom sections?
Expand Down
64 changes: 55 additions & 9 deletions frontend-wasm/src/sections_translator.rs
Original file line number Diff line number Diff line change
Expand Up @@ -6,14 +6,15 @@ use crate::{
error::{WasmError, WasmResult},
unsupported_diag,
wasm_types::{
convert_func_type, convert_global_type, FuncIndex, GlobalIndex, GlobalInit, TypeIndex,
convert_func_type, convert_global_type, DataSegment, DataSegmentIndex, DataSegmentOffset,
FuncIndex, GlobalIndex, GlobalInit, TypeIndex,
},
};
use miden_diagnostics::DiagnosticsHandler;
use wasmparser::{
DataSectionReader, ElementSectionReader, FunctionSectionReader, GlobalSectionReader,
ImportSectionReader, MemorySectionReader, NameSectionReader, Naming, Operator, Type, TypeRef,
TypeSectionReader,
Data, DataKind, DataSectionReader, ElementSectionReader, FunctionSectionReader,
GlobalSectionReader, ImportSectionReader, MemorySectionReader, NameSectionReader, Naming,
Operator, Type, TypeRef, TypeSectionReader,
};

/// Parses the Type section of the wasm module.
Expand Down Expand Up @@ -139,11 +140,49 @@ pub fn parse_element_section<'a>(

/// Parses the Data section of the wasm module.
pub fn parse_data_section<'a>(
_data: DataSectionReader<'a>,
_environ: &mut ModuleEnvironment<'a>,
_diagnostics: &DiagnosticsHandler,
data: DataSectionReader<'a>,
environ: &mut ModuleEnvironment<'a>,
diagnostics: &DiagnosticsHandler,
) -> WasmResult<()> {
todo!("Data section are not yet implemented");
for (_index, entry) in data.into_iter().enumerate() {
let Data {
kind,
data,
range: _,
} = entry?;
match kind {
DataKind::Active {
// ignored, since for Wasm spec v1 it's always 0
memory_index: _,
offset_expr,
} => {
let mut offset_expr_reader = offset_expr.get_binary_reader();
let offset = match offset_expr_reader.read_operator()? {
Operator::I32Const { value } => DataSegmentOffset::I32Const(value),
Operator::GlobalGet { global_index } => {
DataSegmentOffset::GetGlobal(GlobalIndex::from_u32(global_index))
}
ref s => {
unsupported_diag!(
diagnostics,
"unsupported init expr in data section offset: {:?}",
s
);
}
};
let segment = DataSegment {
offset,
data: data.to_owned(),
};
environ.declare_data_segment(segment);
}
DataKind::Passive => {
// Passive data segments type is added in Wasm spec 2.0
unsupported_diag!(diagnostics, "Passive data segments are not supported");
}
}
}
Ok(())
}

/// Parses the Name section of the wasm module.
Expand Down Expand Up @@ -185,12 +224,19 @@ pub fn parse_name_section<'a>(
}
}
}
wasmparser::Name::Data(names) => {
for name in names {
let Naming { index, name } = name?;
if index != u32::max_value() {
environ.declare_data_segment_name(DataSegmentIndex::from_u32(index), name);
}
}
}
wasmparser::Name::Label(_)
| wasmparser::Name::Type(_)
| wasmparser::Name::Table(_)
| wasmparser::Name::Memory(_)
| wasmparser::Name::Element(_)
| wasmparser::Name::Data(_)
| wasmparser::Name::Unknown { .. } => {}
}
}
Expand Down
73 changes: 72 additions & 1 deletion frontend-wasm/src/wasm_types.rs
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
//! Internal types for parsed WebAssembly.

use miden_diagnostics::DiagnosticsHandler;
use miden_hir::cranelift_entity::entity_impl;
use miden_hir::cranelift_entity::PrimaryMap;
use miden_hir_type::FunctionType;
Expand All @@ -8,6 +9,7 @@ use miden_hir_type::Type;
use crate::environ::ModuleInfo;
use crate::error::WasmError;
use crate::error::WasmResult;
use crate::unsupported_diag;

/// Index type of a function (imported or defined) inside the WebAssembly module.
#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
Expand All @@ -20,7 +22,7 @@ pub struct DefinedFuncIndex(u32);
entity_impl!(DefinedFuncIndex);

/// Index type of a global variable (imported or defined) inside the WebAssembly module.
#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug, derive_more::Display)]
pub struct GlobalIndex(u32);
entity_impl!(GlobalIndex);

Expand All @@ -34,6 +36,11 @@ entity_impl!(MemoryIndex);
pub struct TypeIndex(u32);
entity_impl!(TypeIndex);

/// Index type of a data segment inside the WebAssembly module.
#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord, Debug)]
pub struct DataSegmentIndex(u32);
entity_impl!(DataSegmentIndex);

/// A WebAssembly global.
#[derive(Debug, Clone, Hash, Eq, PartialEq)]
pub struct Global {
Expand Down Expand Up @@ -74,6 +81,23 @@ impl GlobalInit {
}
}
}

pub fn as_i32(
&self,
globals: &PrimaryMap<GlobalIndex, Global>,
diagnostics: &DiagnosticsHandler,
) -> WasmResult<i32> {
Ok(match self {
GlobalInit::I32Const(x) => *x,
GlobalInit::GetGlobal(global_idx) => {
let global = &globals[*global_idx];
global.init.as_i32(globals, diagnostics)?
}
g => {
unsupported_diag!(diagnostics, "Expected global init to be i32, got: {:?}", g);
}
})
}
}

/// WebAssembly linear memory.
Expand All @@ -97,6 +121,53 @@ impl From<wasmparser::MemoryType> for Memory {
}
}

/// Offset of a data segment inside a linear memory.
#[derive(Debug, Clone, Copy, Hash, Eq, PartialEq)]
pub enum DataSegmentOffset {
/// An `i32.const` offset.
I32Const(i32),
/// An offset as a `global.get` of another global.
GetGlobal(GlobalIndex),
}

impl DataSegmentOffset {
/// Returns the offset as a i32, resolving the global if necessary.
pub fn as_i32(
&self,
globals: &PrimaryMap<GlobalIndex, Global>,
diagnostics: &DiagnosticsHandler,
) -> WasmResult<i32> {
Ok(match self {
DataSegmentOffset::I32Const(x) => *x,
DataSegmentOffset::GetGlobal(global_idx) => {
let global = &globals[*global_idx];
match global.init.as_i32(globals, diagnostics) {
Err(e) => {
diagnostics
.diagnostic(miden_diagnostics::Severity::Error)
.with_message(format!(
"Failed to get data segment offset from global init {:?} with global index {global_idx}",
global.init,
))
.emit();
return Err(e);
}
Ok(v) => v,
}
}
})
}
}

/// A WebAssembly data segment.
/// https://www.w3.org/TR/wasm-core-1/#data-segments%E2%91%A0
pub struct DataSegment {
/// The offset of the data segment inside the linear memory.
pub offset: DataSegmentOffset,
/// The initialization data.
pub data: Vec<u8>,
}

#[derive(Debug, Clone, PartialEq, Eq, Hash, Default)]
pub struct BlockType {
pub params: Vec<Type>,
Expand Down
18 changes: 18 additions & 0 deletions frontend-wasm/tests/rust_source/array.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,18 @@
#![no_std]
#![no_main]

#[panic_handler]
fn my_panic(_info: &core::panic::PanicInfo) -> ! {
loop {}
}

#[inline(never)]
#[no_mangle]
pub fn sum_arr(arr: &[u32]) -> u32 {
arr.iter().sum()
}

#[no_mangle]
pub extern "C" fn __main() -> u32 {
sum_arr(&[1, 2, 3, 4, 5]) + sum_arr(&[6, 7, 8, 9, 10])
}
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