feat: new parser architecture

Signed-off-by: Henry Gressmann <mail@henrygressmann.de>

1 files changed, 487 insertions, 0 deletions

diff --git a/crates/parser/src/visit.rs b/crates/parser/src/visit.rs
new file mode 100644
index 0000000..b42e462
--- /dev/null
+++ b/crates/parser/src/visit.rs
@@ -0,0 +1,487 @@
+use crate::{conversion::convert_blocktype, Result};
+
+use crate::conversion::{convert_heaptype, convert_memarg, convert_valtype};
+use alloc::string::ToString;
+use alloc::{boxed::Box, format, vec::Vec};
+use tinywasm_types::Instruction;
+use wasmparser::{FuncValidator, FunctionBody, VisitOperator, WasmModuleResources};
+
+struct ValidateThenVisit<'a, T, U>(T, &'a mut U);
+macro_rules! validate_then_visit {
+    ($( @$proposal:ident $op:ident $({ $($arg:ident: $argty:ty),* })? => $visit:ident)*) => {
+        $(
+            fn $visit(&mut self $($(,$arg: $argty)*)?) -> Self::Output {
+                self.0.$visit($($($arg.clone()),*)?)?;
+                Ok(self.1.$visit($($($arg),*)?))
+            }
+        )*
+    };
+}
+
+impl<'a, T, U> VisitOperator<'a> for ValidateThenVisit<'_, T, U>
+where
+    T: VisitOperator<'a, Output = wasmparser::Result<()>>,
+    U: VisitOperator<'a>,
+{
+    type Output = Result<U::Output>;
+
+    wasmparser::for_each_operator!(validate_then_visit);
+}
+
+pub(crate) fn process_operators<R: WasmModuleResources>(
+    validator: &mut FuncValidator<R>,
+    body: &FunctionBody<'_>,
+) -> Result<Box<[Instruction]>> {
+    let mut reader = body.get_operators_reader()?;
+    let mut builder = FunctionBuilder::new(1024);
+
+    while !reader.eof() {
+        let validate = validator.visitor(reader.original_position());
+        reader.visit_operator(&mut ValidateThenVisit(validate, &mut builder))???;
+    }
+
+    validator.finish(reader.original_position())?;
+    Ok(builder.instructions.into_boxed_slice())
+}
+
+macro_rules! define_operands {
+    ($($name:ident, $instr:expr),*) => {
+        $(
+            fn $name(&mut self) -> Self::Output {
+                self.instructions.push($instr);
+                Ok(())
+            }
+        )*
+    };
+}
+
+macro_rules! define_primitive_operands {
+    ($($name:ident, $instr:expr, $ty:ty),*) => {
+        $(
+            fn $name(&mut self, arg: $ty) -> Self::Output {
+                self.instructions.push($instr(arg));
+                Ok(())
+            }
+        )*
+    };
+}
+
+macro_rules! define_mem_operands {
+    ($($name:ident, $instr:expr),*) => {
+        $(
+            fn $name(&mut self, mem_arg: wasmparser::MemArg) -> Self::Output {
+                self.instructions.push($instr(
+                    convert_memarg(mem_arg)
+                ));
+                Ok(())
+            }
+        )*
+    };
+}
+
+macro_rules! impl_visit_operator {
+    ( @mvp $($rest:tt)* ) => {
+        impl_visit_operator!(@@skipped $($rest)*);
+    };
+    ( @sign_extension $($rest:tt)* ) => {
+        impl_visit_operator!(@@skipped $($rest)*);
+    };
+    ( @saturating_float_to_int $($rest:tt)* ) => {
+        impl_visit_operator!(@@skipped $($rest)*);
+    };
+    ( @bulk_memory $($rest:tt)* ) => {
+        impl_visit_operator!(@@skipped $($rest)*);
+    };
+    ( @reference_types $($rest:tt)* ) => {
+        impl_visit_operator!(@@skipped $($rest)*);
+    };
+    ( @@skipped $op:ident $({ $($arg:ident: $argty:ty),* })? => $visit:ident $($rest:tt)* ) => {
+        impl_visit_operator!($($rest)*);
+    };
+    ( @$proposal:ident $op:ident $({ $($arg:ident: $argty:ty),* })? => $visit:ident $($rest:tt)* ) => {
+        fn $visit(&mut self $($(, $arg: $argty)*)?) -> Self::Output {
+            self.unsupported(stringify!($op))
+        }
+        impl_visit_operator!($($rest)*);
+    };
+    () => {};
+}
+
+pub(crate) struct FunctionBuilder {
+    instructions: Vec<Instruction>,
+    label_ptrs: Vec<usize>,
+}
+
+impl FunctionBuilder {
+    pub(crate) fn new(instr_capacity: usize) -> Self {
+        Self { instructions: Vec::with_capacity(instr_capacity), label_ptrs: Vec::with_capacity(64) }
+    }
+
+    #[cold]
+    fn unsupported(&self, name: &str) -> Result<()> {
+        Err(crate::ParseError::UnsupportedOperator(format!("Unsupported instruction: {:?}", name)))
+    }
+
+    #[inline]
+    fn visit(&mut self, op: Instruction) -> Result<()> {
+        Ok(self.instructions.push(op))
+    }
+}
+
+impl<'a> wasmparser::VisitOperator<'a> for FunctionBuilder {
+    type Output = Result<()>;
+
+    define_primitive_operands! {
+        visit_br, Instruction::Br, u32,
+        visit_br_if, Instruction::BrIf, u32,
+        visit_local_get, Instruction::LocalGet, u32,
+        visit_local_set, Instruction::LocalSet, u32,
+        visit_local_tee, Instruction::LocalTee, u32,
+        visit_global_get, Instruction::GlobalGet, u32,
+        visit_global_set, Instruction::GlobalSet, u32,
+        visit_i32_const, Instruction::I32Const, i32,
+        visit_i64_const, Instruction::I64Const, i64
+    }
+
+    define_mem_operands! {
+        visit_i32_load, Instruction::I32Load,
+        visit_i64_load, Instruction::I64Load,
+        visit_f32_load, Instruction::F32Load,
+        visit_f64_load, Instruction::F64Load,
+        visit_i32_load8_s, Instruction::I32Load8S,
+        visit_i32_load8_u, Instruction::I32Load8U,
+        visit_i32_load16_s, Instruction::I32Load16S,
+        visit_i32_load16_u, Instruction::I32Load16U,
+        visit_i64_load8_s, Instruction::I64Load8S,
+        visit_i64_load8_u, Instruction::I64Load8U,
+        visit_i64_load16_s, Instruction::I64Load16S,
+        visit_i64_load16_u, Instruction::I64Load16U,
+        visit_i64_load32_s, Instruction::I64Load32S,
+        visit_i64_load32_u, Instruction::I64Load32U,
+        visit_i32_store, Instruction::I32Store,
+        visit_i64_store, Instruction::I64Store,
+        visit_f32_store, Instruction::F32Store,
+        visit_f64_store, Instruction::F64Store,
+        visit_i32_store8, Instruction::I32Store8,
+        visit_i32_store16, Instruction::I32Store16,
+        visit_i64_store8, Instruction::I64Store8,
+        visit_i64_store16, Instruction::I64Store16,
+        visit_i64_store32, Instruction::I64Store32
+    }
+
+    define_operands! {
+        visit_unreachable, Instruction::Unreachable,
+        visit_nop, Instruction::Nop,
+        visit_return, Instruction::Return,
+        visit_drop, Instruction::Drop,
+        visit_select, Instruction::Select(None),
+        visit_i32_eqz, Instruction::I32Eqz,
+        visit_i32_eq, Instruction::I32Eq,
+        visit_i32_ne, Instruction::I32Ne,
+        visit_i32_lt_s, Instruction::I32LtS,
+        visit_i32_lt_u, Instruction::I32LtU,
+        visit_i32_gt_s, Instruction::I32GtS,
+        visit_i32_gt_u, Instruction::I32GtU,
+        visit_i32_le_s, Instruction::I32LeS,
+        visit_i32_le_u, Instruction::I32LeU,
+        visit_i32_ge_s, Instruction::I32GeS,
+        visit_i32_ge_u, Instruction::I32GeU,
+        visit_i64_eqz, Instruction::I64Eqz,
+        visit_i64_eq, Instruction::I64Eq,
+        visit_i64_ne, Instruction::I64Ne,
+        visit_i64_lt_s, Instruction::I64LtS,
+        visit_i64_lt_u, Instruction::I64LtU,
+        visit_i64_gt_s, Instruction::I64GtS,
+        visit_i64_gt_u, Instruction::I64GtU,
+        visit_i64_le_s, Instruction::I64LeS,
+        visit_i64_le_u, Instruction::I64LeU,
+        visit_i64_ge_s, Instruction::I64GeS,
+        visit_i64_ge_u, Instruction::I64GeU,
+        visit_f32_eq, Instruction::F32Eq,
+        visit_f32_ne, Instruction::F32Ne,
+        visit_f32_lt, Instruction::F32Lt,
+        visit_f32_gt, Instruction::F32Gt,
+        visit_f32_le, Instruction::F32Le,
+        visit_f32_ge, Instruction::F32Ge,
+        visit_f64_eq, Instruction::F64Eq,
+        visit_f64_ne, Instruction::F64Ne,
+        visit_f64_lt, Instruction::F64Lt,
+        visit_f64_gt, Instruction::F64Gt,
+        visit_f64_le, Instruction::F64Le,
+        visit_f64_ge, Instruction::F64Ge,
+        visit_i32_clz, Instruction::I32Clz,
+        visit_i32_ctz, Instruction::I32Ctz,
+        visit_i32_popcnt, Instruction::I32Popcnt,
+        visit_i32_add, Instruction::I32Add,
+        visit_i32_sub, Instruction::I32Sub,
+        visit_i32_mul, Instruction::I32Mul,
+        visit_i32_div_s, Instruction::I32DivS,
+        visit_i32_div_u, Instruction::I32DivU,
+        visit_i32_rem_s, Instruction::I32RemS,
+        visit_i32_rem_u, Instruction::I32RemU,
+        visit_i32_and, Instruction::I32And,
+        visit_i32_or, Instruction::I32Or,
+        visit_i32_xor, Instruction::I32Xor,
+        visit_i32_shl, Instruction::I32Shl,
+        visit_i32_shr_s, Instruction::I32ShrS,
+        visit_i32_shr_u, Instruction::I32ShrU,
+        visit_i32_rotl, Instruction::I32Rotl,
+        visit_i32_rotr, Instruction::I32Rotr,
+        visit_i64_clz, Instruction::I64Clz,
+        visit_i64_ctz, Instruction::I64Ctz,
+        visit_i64_popcnt, Instruction::I64Popcnt,
+        visit_i64_add, Instruction::I64Add,
+        visit_i64_sub, Instruction::I64Sub,
+        visit_i64_mul, Instruction::I64Mul,
+        visit_i64_div_s, Instruction::I64DivS,
+        visit_i64_div_u, Instruction::I64DivU,
+        visit_i64_rem_s, Instruction::I64RemS,
+        visit_i64_rem_u, Instruction::I64RemU,
+        visit_i64_and, Instruction::I64And,
+        visit_i64_or, Instruction::I64Or,
+        visit_i64_xor, Instruction::I64Xor,
+        visit_i64_shl, Instruction::I64Shl,
+        visit_i64_shr_s, Instruction::I64ShrS,
+        visit_i64_shr_u, Instruction::I64ShrU,
+        visit_i64_rotl, Instruction::I64Rotl,
+        visit_i64_rotr, Instruction::I64Rotr,
+        visit_f32_abs, Instruction::F32Abs,
+        visit_f32_neg, Instruction::F32Neg,
+        visit_f32_ceil, Instruction::F32Ceil,
+        visit_f32_floor, Instruction::F32Floor,
+        visit_f32_trunc, Instruction::F32Trunc,
+        visit_f32_nearest, Instruction::F32Nearest,
+        visit_f32_sqrt, Instruction::F32Sqrt,
+        visit_f32_add, Instruction::F32Add,
+        visit_f32_sub, Instruction::F32Sub,
+        visit_f32_mul, Instruction::F32Mul,
+        visit_f32_div, Instruction::F32Div,
+        visit_f32_min, Instruction::F32Min,
+        visit_f32_max, Instruction::F32Max,
+        visit_f32_copysign, Instruction::F32Copysign,
+        visit_f64_abs, Instruction::F64Abs,
+        visit_f64_neg, Instruction::F64Neg,
+        visit_f64_ceil, Instruction::F64Ceil,
+        visit_f64_floor, Instruction::F64Floor,
+        visit_f64_trunc, Instruction::F64Trunc,
+        visit_f64_nearest, Instruction::F64Nearest,
+        visit_f64_sqrt, Instruction::F64Sqrt,
+        visit_f64_add, Instruction::F64Add,
+        visit_f64_sub, Instruction::F64Sub,
+        visit_f64_mul, Instruction::F64Mul,
+        visit_f64_div, Instruction::F64Div,
+        visit_f64_min, Instruction::F64Min,
+        visit_f64_max, Instruction::F64Max,
+        visit_f64_copysign, Instruction::F64Copysign,
+        visit_i32_wrap_i64, Instruction::I32WrapI64,
+        visit_i32_trunc_f32_s, Instruction::I32TruncF32S,
+        visit_i32_trunc_f32_u, Instruction::I32TruncF32U,
+        visit_i32_trunc_f64_s, Instruction::I32TruncF64S,
+        visit_i32_trunc_f64_u, Instruction::I32TruncF64U,
+        visit_i64_extend_i32_s, Instruction::I64ExtendI32S,
+        visit_i64_extend_i32_u, Instruction::I64ExtendI32U,
+        visit_i64_trunc_f32_s, Instruction::I64TruncF32S,
+        visit_i64_trunc_f32_u, Instruction::I64TruncF32U,
+        visit_i64_trunc_f64_s, Instruction::I64TruncF64S,
+        visit_i64_trunc_f64_u, Instruction::I64TruncF64U,
+        visit_f32_convert_i32_s, Instruction::F32ConvertI32S,
+        visit_f32_convert_i32_u, Instruction::F32ConvertI32U,
+        visit_f32_convert_i64_s, Instruction::F32ConvertI64S,
+        visit_f32_convert_i64_u, Instruction::F32ConvertI64U,
+        visit_f32_demote_f64, Instruction::F32DemoteF64,
+        visit_f64_convert_i32_s, Instruction::F64ConvertI32S,
+        visit_f64_convert_i32_u, Instruction::F64ConvertI32U,
+        visit_f64_convert_i64_s, Instruction::F64ConvertI64S,
+        visit_f64_convert_i64_u, Instruction::F64ConvertI64U,
+        visit_f64_promote_f32, Instruction::F64PromoteF32,
+        visit_i32_reinterpret_f32, Instruction::I32ReinterpretF32,
+        visit_i64_reinterpret_f64, Instruction::I64ReinterpretF64,
+        visit_f32_reinterpret_i32, Instruction::F32ReinterpretI32,
+        visit_f64_reinterpret_i64, Instruction::F64ReinterpretI64,
+
+        // sign_extension
+        visit_i32_extend8_s, Instruction::I32Extend8S,
+        visit_i32_extend16_s, Instruction::I32Extend16S,
+        visit_i64_extend8_s, Instruction::I64Extend8S,
+        visit_i64_extend16_s, Instruction::I64Extend16S,
+        visit_i64_extend32_s, Instruction::I64Extend32S,
+
+        // Non-trapping Float-to-int Conversions
+        visit_i32_trunc_sat_f32_s, Instruction::I32TruncSatF32S,
+        visit_i32_trunc_sat_f32_u, Instruction::I32TruncSatF32U,
+        visit_i32_trunc_sat_f64_s, Instruction::I32TruncSatF64S,
+        visit_i32_trunc_sat_f64_u, Instruction::I32TruncSatF64U,
+        visit_i64_trunc_sat_f32_s, Instruction::I64TruncSatF32S,
+        visit_i64_trunc_sat_f32_u, Instruction::I64TruncSatF32U,
+        visit_i64_trunc_sat_f64_s, Instruction::I64TruncSatF64S,
+        visit_i64_trunc_sat_f64_u, Instruction::I64TruncSatF64U
+    }
+
+    fn visit_block(&mut self, blockty: wasmparser::BlockType) -> Self::Output {
+        self.label_ptrs.push(self.instructions.len());
+        self.visit(Instruction::Block(convert_blocktype(blockty), 0))
+    }
+
+    fn visit_loop(&mut self, ty: wasmparser::BlockType) -> Self::Output {
+        self.label_ptrs.push(self.instructions.len());
+        self.visit(Instruction::Loop(convert_blocktype(ty), 0))
+    }
+
+    fn visit_if(&mut self, ty: wasmparser::BlockType) -> Self::Output {
+        self.label_ptrs.push(self.instructions.len());
+        self.visit(Instruction::If(convert_blocktype(ty), None, 0))
+    }
+
+    fn visit_else(&mut self) -> Self::Output {
+        self.label_ptrs.push(self.instructions.len());
+        self.visit(Instruction::Else(0))
+    }
+
+    fn visit_end(&mut self) -> Self::Output {
+        let Some(label_pointer) = self.label_ptrs.pop() else {
+            return self.visit(Instruction::EndFunc);
+        };
+
+        let current_instr_ptr = self.instructions.len();
+
+        match self.instructions[label_pointer] {
+            Instruction::Else(ref mut else_instr_end_offset) => {
+                *else_instr_end_offset = current_instr_ptr - label_pointer;
+
+                // since we're ending an else block, we need to end the if block as well
+                let if_label_pointer = self.label_ptrs.pop().ok_or(crate::ParseError::UnsupportedOperator(
+                    "Expected to end an if block, but the last label was not an if".to_string(),
+                ))?;
+
+                let if_instruction = &mut self.instructions[if_label_pointer];
+                let Instruction::If(_, ref mut else_offset, ref mut end_offset) = if_instruction else {
+                    return Err(crate::ParseError::UnsupportedOperator(
+                        "Expected to end an if block, but the last label was not an if".to_string(),
+                    ));
+                };
+
+                *else_offset = Some(label_pointer - if_label_pointer);
+                *end_offset = current_instr_ptr - if_label_pointer;
+            }
+            Instruction::Block(_, ref mut end_offset)
+            | Instruction::Loop(_, ref mut end_offset)
+            | Instruction::If(_, _, ref mut end_offset) => {
+                *end_offset = current_instr_ptr - label_pointer;
+            }
+            _ => {
+                return Err(crate::ParseError::UnsupportedOperator(
+                    "Expected to end a block, but the last label was not a block".to_string(),
+                ))
+            }
+        };
+
+        self.visit(Instruction::EndBlockFrame)
+    }
+
+    fn visit_br_table(&mut self, targets: wasmparser::BrTable<'_>) -> Self::Output {
+        let def = targets.default();
+        let instrs = targets
+            .targets()
+            .map(|t| t.map(Instruction::BrLabel))
+            .collect::<Result<Vec<Instruction>, wasmparser::BinaryReaderError>>()
+            .expect("BrTable targets are invalid, this should have been caught by the validator");
+
+        self.instructions
+            .extend(IntoIterator::into_iter([Instruction::BrTable(def, instrs.len())]).chain(instrs.into_iter()));
+        Ok(())
+    }
+
+    fn visit_call(&mut self, idx: u32) -> Self::Output {
+        self.visit(Instruction::Call(idx))
+    }
+
+    fn visit_call_indirect(&mut self, ty: u32, table: u32, _table_byte: u8) -> Self::Output {
+        self.visit(Instruction::CallIndirect(ty, table))
+    }
+
+    fn visit_memory_size(&mut self, mem: u32, mem_byte: u8) -> Self::Output {
+        self.visit(Instruction::MemorySize(mem, mem_byte))
+    }
+
+    fn visit_memory_grow(&mut self, mem: u32, mem_byte: u8) -> Self::Output {
+        self.visit(Instruction::MemoryGrow(mem, mem_byte))
+    }
+
+    fn visit_f32_const(&mut self, val: wasmparser::Ieee32) -> Self::Output {
+        self.visit(Instruction::F32Const(f32::from_bits(val.bits())))
+    }
+
+    fn visit_f64_const(&mut self, val: wasmparser::Ieee64) -> Self::Output {
+        self.visit(Instruction::F64Const(f64::from_bits(val.bits())))
+    }
+
+    // Bulk Memory Operations
+
+    fn visit_memory_init(&mut self, data_index: u32, mem: u32) -> Self::Output {
+        self.visit(Instruction::MemoryInit(data_index, mem))
+    }
+
+    fn visit_data_drop(&mut self, data_index: u32) -> Self::Output {
+        self.visit(Instruction::DataDrop(data_index))
+    }
+
+    fn visit_memory_copy(&mut self, dst_mem: u32, src_mem: u32) -> Self::Output {
+        self.visit(Instruction::MemoryCopy(dst_mem, src_mem))
+    }
+
+    fn visit_memory_fill(&mut self, mem: u32) -> Self::Output {
+        self.visit(Instruction::MemoryFill(mem))
+    }
+
+    fn visit_table_init(&mut self, elem_index: u32, table: u32) -> Self::Output {
+        self.visit(Instruction::TableInit(elem_index, table))
+    }
+
+    fn visit_elem_drop(&mut self, _elem_index: u32) -> Self::Output {
+        self.unsupported("elem_drop")
+    }
+
+    fn visit_table_copy(&mut self, dst_table: u32, src_table: u32) -> Self::Output {
+        self.visit(Instruction::TableCopy { from: src_table, to: dst_table })
+    }
+
+    // Reference Types
+
+    fn visit_ref_null(&mut self, ty: wasmparser::HeapType) -> Self::Output {
+        self.visit(Instruction::RefNull(convert_heaptype(ty)))
+    }
+
+    fn visit_ref_is_null(&mut self) -> Self::Output {
+        self.visit(Instruction::RefIsNull)
+    }
+
+    fn visit_ref_func(&mut self, idx: u32) -> Self::Output {
+        self.visit(Instruction::RefFunc(idx))
+    }
+
+    fn visit_typed_select(&mut self, ty: wasmparser::ValType) -> Self::Output {
+        self.visit(Instruction::Select(Some(convert_valtype(&ty))))
+    }
+
+    fn visit_table_fill(&mut self, table: u32) -> Self::Output {
+        self.visit(Instruction::TableFill(table))
+    }
+
+    fn visit_table_get(&mut self, table: u32) -> Self::Output {
+        self.visit(Instruction::TableGet(table))
+    }
+
+    fn visit_table_set(&mut self, table: u32) -> Self::Output {
+        self.visit(Instruction::TableSet(table))
+    }
+
+    fn visit_table_grow(&mut self, table: u32) -> Self::Output {
+        self.visit(Instruction::TableGrow(table))
+    }
+
+    fn visit_table_size(&mut self, table: u32) -> Self::Output {
+        self.visit(Instruction::TableSize(table))
+    }
+
+    wasmparser::for_each_operator!(impl_visit_operator);
+}