diff options
Diffstat (limited to 'third_party/rust/wast/src/core/resolve/types.rs')
| -rw-r--r-- | third_party/rust/wast/src/core/resolve/types.rs | 271 |
1 files changed, 271 insertions, 0 deletions
diff --git a/third_party/rust/wast/src/core/resolve/types.rs b/third_party/rust/wast/src/core/resolve/types.rs new file mode 100644 index 0000000000..bfb996b4b6 --- /dev/null +++ b/third_party/rust/wast/src/core/resolve/types.rs @@ -0,0 +1,271 @@ +use crate::core::*; +use crate::gensym; +use crate::token::{Index, Span}; +use std::collections::HashMap; + +pub fn expand<'a>(fields: &mut Vec<ModuleField<'a>>) { + let mut expander = Expander::default(); + expander.process(fields); +} + +#[derive(Default)] +pub(crate) struct Expander<'a> { + // Maps used to "intern" types. These maps are populated as type annotations + // are seen and inline type annotations use previously defined ones if + // there's a match. + func_type_to_idx: HashMap<FuncKey<'a>, Index<'a>>, + + /// Fields, during processing, which should be prepended to the + /// currently-being-processed field. This should always be empty after + /// processing is complete. + to_prepend: Vec<ModuleField<'a>>, +} + +impl<'a> Expander<'a> { + fn process(&mut self, fields: &mut Vec<ModuleField<'a>>) { + // Next we expand "header" fields which are those like types and + // imports. In this context "header" is defined by the previous + // `process_imports_early` annotation. + let mut cur = 0; + while cur < fields.len() { + self.expand_header(&mut fields[cur]); + for item in self.to_prepend.drain(..) { + fields.insert(cur, item); + cur += 1; + } + cur += 1; + } + + // Next after we've done that we expand remaining fields. Note that + // after this we actually append instead of prepend. This is because + // injected types are intended to come at the end of the type section + // and types will be sorted before all other items processed here in the + // final module anyway. + for field in fields.iter_mut() { + self.expand(field); + } + fields.append(&mut self.to_prepend); + } + + fn expand_header(&mut self, item: &mut ModuleField<'a>) { + match item { + ModuleField::Type(ty) => { + let id = gensym::fill(ty.span, &mut ty.id); + match &mut ty.def { + TypeDef::Func(f) => { + f.key().insert(self, Index::Id(id)); + } + TypeDef::Array(_) | TypeDef::Struct(_) => {} + } + } + _ => {} + } + } + + fn expand(&mut self, item: &mut ModuleField<'a>) { + match item { + // This is pre-expanded above + ModuleField::Type(_) => {} + ModuleField::Rec(_) => {} + + ModuleField::Import(i) => { + self.expand_item_sig(&mut i.item); + } + ModuleField::Func(f) => { + self.expand_type_use(&mut f.ty); + if let FuncKind::Inline { expression, .. } = &mut f.kind { + self.expand_expression(expression); + } + } + ModuleField::Global(g) => { + if let GlobalKind::Inline(expr) = &mut g.kind { + self.expand_expression(expr); + } + } + ModuleField::Data(d) => { + if let DataKind::Active { offset, .. } = &mut d.kind { + self.expand_expression(offset); + } + } + ModuleField::Elem(e) => { + if let ElemKind::Active { offset, .. } = &mut e.kind { + self.expand_expression(offset); + } + if let ElemPayload::Exprs { exprs, .. } = &mut e.payload { + for expr in exprs { + self.expand_expression(expr); + } + } + } + ModuleField::Tag(t) => match &mut t.ty { + TagType::Exception(ty) => { + self.expand_type_use(ty); + } + }, + + ModuleField::Table(t) => match &mut t.kind { + TableKind::Normal { init_expr, .. } => { + if let Some(expr) = init_expr { + self.expand_expression(expr); + } + } + TableKind::Import { .. } | TableKind::Inline { .. } => {} + }, + + ModuleField::Memory(_) + | ModuleField::Start(_) + | ModuleField::Export(_) + | ModuleField::Custom(_) => {} + } + } + + fn expand_item_sig(&mut self, item: &mut ItemSig<'a>) { + match &mut item.kind { + ItemKind::Func(t) | ItemKind::Tag(TagType::Exception(t)) => { + self.expand_type_use(t); + } + ItemKind::Global(_) | ItemKind::Table(_) | ItemKind::Memory(_) => {} + } + } + + fn expand_expression(&mut self, expr: &mut Expression<'a>) { + for instr in expr.instrs.iter_mut() { + self.expand_instr(instr); + } + } + + fn expand_instr(&mut self, instr: &mut Instruction<'a>) { + match instr { + Instruction::Block(bt) + | Instruction::If(bt) + | Instruction::Loop(bt) + | Instruction::Let(LetType { block: bt, .. }) + | Instruction::Try(bt) + | Instruction::TryTable(TryTable { block: bt, .. }) => { + // No expansion necessary, a type reference is already here. + // We'll verify that it's the same as the inline type, if any, + // later. + if bt.ty.index.is_some() { + return; + } + + match &bt.ty.inline { + // Only actually expand `TypeUse` with an index which appends a + // type if it looks like we need one. This way if the + // multi-value proposal isn't enabled and/or used we won't + // encode it. + Some(inline) => { + if inline.params.len() == 0 && inline.results.len() <= 1 { + return; + } + } + + // If we didn't have either an index or an inline type + // listed then assume our block has no inputs/outputs, so + // fill in the inline type here. + // + // Do not fall through to expanding the `TypeUse` because + // this doesn't force an empty function type to go into the + // type section. + None => { + bt.ty.inline = Some(FunctionType::default()); + return; + } + } + self.expand_type_use(&mut bt.ty); + } + Instruction::FuncBind(b) => { + self.expand_type_use(&mut b.ty); + } + Instruction::CallIndirect(c) | Instruction::ReturnCallIndirect(c) => { + self.expand_type_use(&mut c.ty); + } + _ => {} + } + } + + fn expand_type_use<T>(&mut self, item: &mut TypeUse<'a, T>) -> Index<'a> + where + T: TypeReference<'a>, + { + if let Some(idx) = &item.index { + return *idx; + } + let key = match item.inline.as_mut() { + Some(ty) => { + ty.expand(self); + ty.key() + } + None => T::default().key(), + }; + let span = Span::from_offset(0); // FIXME(#613): don't manufacture + let idx = self.key_to_idx(span, key); + item.index = Some(idx); + idx + } + + fn key_to_idx(&mut self, span: Span, key: impl TypeKey<'a>) -> Index<'a> { + // First see if this `key` already exists in the type definitions we've + // seen so far... + if let Some(idx) = key.lookup(self) { + return idx; + } + + // ... and failing that we insert a new type definition. + let id = gensym::gen(span); + self.to_prepend.push(ModuleField::Type(Type { + span, + id: Some(id), + name: None, + def: key.to_def(span), + parent: None, + final_type: None, + })); + let idx = Index::Id(id); + key.insert(self, idx); + idx + } +} + +pub(crate) trait TypeReference<'a>: Default { + type Key: TypeKey<'a>; + fn key(&self) -> Self::Key; + fn expand(&mut self, cx: &mut Expander<'a>); +} + +pub(crate) trait TypeKey<'a> { + fn lookup(&self, cx: &Expander<'a>) -> Option<Index<'a>>; + fn to_def(&self, span: Span) -> TypeDef<'a>; + fn insert(&self, cx: &mut Expander<'a>, id: Index<'a>); +} + +pub(crate) type FuncKey<'a> = (Box<[ValType<'a>]>, Box<[ValType<'a>]>); + +impl<'a> TypeReference<'a> for FunctionType<'a> { + type Key = FuncKey<'a>; + + fn key(&self) -> Self::Key { + let params = self.params.iter().map(|p| p.2).collect(); + let results = self.results.clone(); + (params, results) + } + + fn expand(&mut self, _cx: &mut Expander<'a>) {} +} + +impl<'a> TypeKey<'a> for FuncKey<'a> { + fn lookup(&self, cx: &Expander<'a>) -> Option<Index<'a>> { + cx.func_type_to_idx.get(self).cloned() + } + + fn to_def(&self, _span: Span) -> TypeDef<'a> { + TypeDef::Func(FunctionType { + params: self.0.iter().map(|t| (None, None, *t)).collect(), + results: self.1.clone(), + }) + } + + fn insert(&self, cx: &mut Expander<'a>, idx: Index<'a>) { + cx.func_type_to_idx.entry(self.clone()).or_insert(idx); + } +} |