🤔 Add a type inference engine, along with typed literals. #4

Merged
acw merged 25 commits from acw/type-checker into develop 2023-09-19 20:40:05 -07:00
3 changed files with 111 additions and 135 deletions
Showing only changes of commit e6ae0ab277 - Show all commits

View File

@@ -137,7 +137,7 @@ impl<M: Module> Backend<M> {
// Look up the value for the variable. Because this might be a
// global variable (and that requires special logic), we just turn
// this into an `Expression` and re-use the logic in that implementation.
let (val, vtype) = Expression::Reference(ann, var).into_crane(
let (val, vtype) = ValueOrRef::Ref(ann, var).into_crane(
&mut builder,
&variable_table,
&pre_defined_symbols,
@@ -251,120 +251,53 @@ impl Expression {
global_variables: &HashMap<String, (GlobalValue, ConstantType)>,
) -> Result<(entities::Value, ConstantType), BackendError> {
match self {
// Values are pretty straightforward to compile, mostly because we only
// have one type of variable, and it's an integer type.
Expression::Value(_, val) => match val {
Value::I8(_, v) => {
Ok((builder.ins().iconst(types::I8, v as i64), ConstantType::I8))
}
Value::I16(_, v) => Ok((
builder.ins().iconst(types::I16, v as i64),
ConstantType::I16,
)),
Value::I32(_, v) => Ok((
builder.ins().iconst(types::I32, v as i64),
ConstantType::I32,
)),
Value::I64(_, v) => Ok((builder.ins().iconst(types::I64, v), ConstantType::I64)),
Value::U8(_, v) => {
Ok((builder.ins().iconst(types::I8, v as i64), ConstantType::U8))
}
Value::U16(_, v) => Ok((
builder.ins().iconst(types::I16, v as i64),
ConstantType::U16,
)),
Value::U32(_, v) => Ok((
builder.ins().iconst(types::I32, v as i64),
ConstantType::U32,
)),
Value::U64(_, v) => Ok((
builder.ins().iconst(types::I64, v as i64),
ConstantType::U64,
)),
},
Expression::Reference(_, name) => {
// first we see if this is a local variable (which is nicer, from an
// optimization point of view.)
if let Some((local_var, etype)) = local_variables.get(&name) {
return Ok((builder.use_var(*local_var), *etype));
}
// then we check to see if this is a global reference, which requires us to
// first lookup where the value is stored, and then load it.
if let Some((global_var, etype)) = global_variables.get(name.as_ref()) {
let cranelift_type = ir::Type::from(*etype);
let val_ptr = builder.ins().symbol_value(cranelift_type, *global_var);
return Ok((
builder
.ins()
.load(cranelift_type, MemFlags::new(), val_ptr, 0),
*etype,
));
}
// this should never happen, because we should have made sure that there are
// no unbound variables a long time before this. but still ...
Err(BackendError::VariableLookupFailure(name))
}
Expression::Atomic(x) => x.into_crane(builder, local_variables, global_variables),
Expression::Cast(_, target_type, expr) => {
let (val, val_type) =
expr.into_crane(builder, local_variables, global_variables)?;
let (val, val_type) = expr.into_crane(builder, local_variables, global_variables)?;
match (val_type, &target_type) {
(ConstantType::I8, Type::Primitive(PrimitiveType::I8)) => Ok((val, val_type)),
(ConstantType::I8, Type::Primitive(PrimitiveType::I16)) => {
Ok((builder.ins().sextend(types::I16, val), ConstantType::I16))
}
(ConstantType::I8, Type::Primitive(PrimitiveType::I32)) => {
Ok((builder.ins().sextend(types::I32, val), ConstantType::I32))
}
(ConstantType::I8, Type::Primitive(PrimitiveType::I64)) => {
Ok((builder.ins().sextend(types::I64, val), ConstantType::I64))
}
(ConstantType::I8, Type::Primitive(PrimitiveType::I16)) =>
Ok((builder.ins().sextend(types::I16, val), ConstantType::I16)),
(ConstantType::I8, Type::Primitive(PrimitiveType::I32)) =>
Ok((builder.ins().sextend(types::I32, val), ConstantType::I32)),
(ConstantType::I8, Type::Primitive(PrimitiveType::I64)) =>
Ok((builder.ins().sextend(types::I64, val), ConstantType::I64)),
(ConstantType::I16, Type::Primitive(PrimitiveType::I16)) => Ok((val, val_type)),
(ConstantType::I16, Type::Primitive(PrimitiveType::I32)) => {
Ok((builder.ins().sextend(types::I32, val), ConstantType::I32))
}
(ConstantType::I16, Type::Primitive(PrimitiveType::I64)) => {
Ok((builder.ins().sextend(types::I64, val), ConstantType::I64))
}
(ConstantType::I16, Type::Primitive(PrimitiveType::I32)) =>
Ok((builder.ins().sextend(types::I32, val), ConstantType::I32)),
(ConstantType::I16, Type::Primitive(PrimitiveType::I64)) =>
Ok((builder.ins().sextend(types::I64, val), ConstantType::I64)),
(ConstantType::I32, Type::Primitive(PrimitiveType::I32)) => Ok((val, val_type)),
(ConstantType::I32, Type::Primitive(PrimitiveType::I64)) => {
Ok((builder.ins().sextend(types::I64, val), ConstantType::I64))
}
(ConstantType::I32, Type::Primitive(PrimitiveType::I64)) =>
Ok((builder.ins().sextend(types::I64, val), ConstantType::I64)),
(ConstantType::I64, Type::Primitive(PrimitiveType::I64)) => Ok((val, val_type)),
(ConstantType::U8, Type::Primitive(PrimitiveType::U8)) => Ok((val, val_type)),
(ConstantType::U8, Type::Primitive(PrimitiveType::U16)) => {
Ok((builder.ins().uextend(types::I16, val), ConstantType::U16))
}
(ConstantType::U8, Type::Primitive(PrimitiveType::U32)) => {
Ok((builder.ins().uextend(types::I32, val), ConstantType::U32))
}
(ConstantType::U8, Type::Primitive(PrimitiveType::U64)) => {
Ok((builder.ins().uextend(types::I64, val), ConstantType::U64))
}
(ConstantType::U8, Type::Primitive(PrimitiveType::U16)) =>
Ok((builder.ins().uextend(types::I16, val), ConstantType::U16)),
(ConstantType::U8, Type::Primitive(PrimitiveType::U32)) =>
Ok((builder.ins().uextend(types::I32, val), ConstantType::U32)),
(ConstantType::U8, Type::Primitive(PrimitiveType::U64)) =>
Ok((builder.ins().uextend(types::I64, val), ConstantType::U64)),
(ConstantType::U16, Type::Primitive(PrimitiveType::U16)) => Ok((val, val_type)),
(ConstantType::U16, Type::Primitive(PrimitiveType::U32)) => {
Ok((builder.ins().uextend(types::I32, val), ConstantType::U32))
}
(ConstantType::U16, Type::Primitive(PrimitiveType::U64)) => {
Ok((builder.ins().uextend(types::I64, val), ConstantType::U64))
}
(ConstantType::U16, Type::Primitive(PrimitiveType::U32)) =>
Ok((builder.ins().uextend(types::I32, val), ConstantType::U32)),
(ConstantType::U16, Type::Primitive(PrimitiveType::U64)) =>
Ok((builder.ins().uextend(types::I64, val), ConstantType::U64)),
(ConstantType::U32, Type::Primitive(PrimitiveType::U32)) => Ok((val, val_type)),
(ConstantType::U32, Type::Primitive(PrimitiveType::U64)) => {
Ok((builder.ins().uextend(types::I64, val), ConstantType::U64))
}
(ConstantType::U32, Type::Primitive(PrimitiveType::U64)) =>
Ok((builder.ins().uextend(types::I64, val), ConstantType::U64)),
(ConstantType::U64, Type::Primitive(PrimitiveType::U64)) => Ok((val, val_type)),
_ => Err(BackendError::InvalidTypeCast {
from: val_type.into(),
to: target_type,
@@ -421,6 +354,63 @@ impl ValueOrRef {
local_variables: &HashMap<ArcIntern<String>, (Variable, ConstantType)>,
global_variables: &HashMap<String, (GlobalValue, ConstantType)>,
) -> Result<(entities::Value, ConstantType), BackendError> {
Expression::from(self).into_crane(builder, local_variables, global_variables)
match self {
// Values are pretty straightforward to compile, mostly because we only
// have one type of variable, and it's an integer type.
ValueOrRef::Value(_, val) => match val {
Value::I8(_, v) => {
Ok((builder.ins().iconst(types::I8, v as i64), ConstantType::I8))
}
Value::I16(_, v) => Ok((
builder.ins().iconst(types::I16, v as i64),
ConstantType::I16,
)),
Value::I32(_, v) => Ok((
builder.ins().iconst(types::I32, v as i64),
ConstantType::I32,
)),
Value::I64(_, v) => Ok((builder.ins().iconst(types::I64, v), ConstantType::I64)),
Value::U8(_, v) => {
Ok((builder.ins().iconst(types::I8, v as i64), ConstantType::U8))
}
Value::U16(_, v) => Ok((
builder.ins().iconst(types::I16, v as i64),
ConstantType::U16,
)),
Value::U32(_, v) => Ok((
builder.ins().iconst(types::I32, v as i64),
ConstantType::U32,
)),
Value::U64(_, v) => Ok((
builder.ins().iconst(types::I64, v as i64),
ConstantType::U64,
)),
},
ValueOrRef::Ref(_, name) => {
// first we see if this is a local variable (which is nicer, from an
// optimization point of view.)
if let Some((local_var, etype)) = local_variables.get(&name) {
return Ok((builder.use_var(*local_var), *etype));
}
// then we check to see if this is a global reference, which requires us to
// first lookup where the value is stored, and then load it.
if let Some((global_var, etype)) = global_variables.get(name.as_ref()) {
let cranelift_type = ir::Type::from(*etype);
let val_ptr = builder.ins().symbol_value(cranelift_type, *global_var);
return Ok((
builder
.ins()
.load(cranelift_type, MemFlags::new(), val_ptr, 0),
*etype,
));
}
// this should never happen, because we should have made sure that there are
// no unbound variables a long time before this. but still ...
Err(BackendError::VariableLookupFailure(name))
}
}
}
}

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@@ -117,8 +117,7 @@ where
/// variable reference.
#[derive(Debug)]
pub enum Expression {
Value(Location, Value),
Reference(Location, Variable),
Atomic(ValueOrRef),
Cast(Location, Type, ValueOrRef),
Primitive(Location, Primitive, Vec<ValueOrRef>),
}
@@ -130,8 +129,7 @@ where
{
fn pretty(self, allocator: &'a D) -> pretty::DocBuilder<'a, D, A> {
match self {
Expression::Value(_, val) => val.pretty(allocator),
Expression::Reference(_, var) => allocator.text(var.as_ref().to_string()),
Expression::Atomic(x) => x.pretty(allocator),
Expression::Cast(_, t, e) => allocator
.text("<")
.append(t.pretty(allocator))
@@ -226,10 +224,7 @@ where
impl From<ValueOrRef> for Expression {
fn from(value: ValueOrRef) -> Self {
match value {
ValueOrRef::Value(loc, val) => Expression::Value(loc, val),
ValueOrRef::Ref(loc, var) => Expression::Reference(loc, var),
}
Expression::Atomic(value)
}
}

View File

@@ -34,26 +34,10 @@ impl Program {
impl Expression {
fn eval(&self, env: &EvalEnvironment) -> Result<Value, EvalError> {
match self {
Expression::Value(_, v) => match v {
super::Value::I8(_, v) => Ok(Value::I8(*v)),
super::Value::I16(_, v) => Ok(Value::I16(*v)),
super::Value::I32(_, v) => Ok(Value::I32(*v)),
super::Value::I64(_, v) => Ok(Value::I64(*v)),
super::Value::U8(_, v) => Ok(Value::U8(*v)),
super::Value::U16(_, v) => Ok(Value::U16(*v)),
super::Value::U32(_, v) => Ok(Value::U32(*v)),
super::Value::U64(_, v) => Ok(Value::U64(*v)),
},
Expression::Reference(_, n) => Ok(env.lookup(n.clone())?),
Expression::Atomic(x) => x.eval(env),
Expression::Cast(_, t, valref) => {
let value = match valref {
ValueOrRef::Ref(_, n) => env.lookup(n.clone())?,
ValueOrRef::Value(loc, val) => {
Expression::Value(loc.clone(), val.clone()).eval(env)?
}
};
let value = valref.eval(env)?;
match t {
Type::Primitive(pt) => Ok(pt.safe_cast(&value)?),
@@ -61,19 +45,7 @@ impl Expression {
}
Expression::Primitive(_, op, args) => {
let mut arg_values = Vec::with_capacity(args.len());
// we implement primitive operations by first evaluating each of the
// arguments to the function, and then gathering up all the values
// produced.
for arg in args.iter() {
match arg {
ValueOrRef::Ref(_, n) => arg_values.push(env.lookup(n.clone())?),
ValueOrRef::Value(loc, val) => {
arg_values.push(Expression::Value(loc.clone(), val.clone()).eval(env)?)
}
}
}
let arg_values = args.iter().map(|x| x.eval(env)).collect::<Result<Vec<Value>, EvalError>>()?;
// and then finally we call `calculate` to run them. trust me, it's nice
// to not have to deal with all the nonsense hidden under `calculate`.
@@ -88,6 +60,25 @@ impl Expression {
}
}
impl ValueOrRef {
fn eval(&self, env: &EvalEnvironment) -> Result<Value, EvalError> {
match self {
ValueOrRef::Value(_, v) => match v {
super::Value::I8(_, v) => Ok(Value::I8(*v)),
super::Value::I16(_, v) => Ok(Value::I16(*v)),
super::Value::I32(_, v) => Ok(Value::I32(*v)),
super::Value::I64(_, v) => Ok(Value::I64(*v)),
super::Value::U8(_, v) => Ok(Value::U8(*v)),
super::Value::U16(_, v) => Ok(Value::U16(*v)),
super::Value::U32(_, v) => Ok(Value::U32(*v)),
super::Value::U64(_, v) => Ok(Value::U64(*v)),
},
ValueOrRef::Ref(_, n) => Ok(env.lookup(n.clone())?),
}
}
}
#[test]
fn two_plus_three() {
let input = crate::syntax::Program::parse(0, "x = 2 + 3; print x;").expect("parse works");