Files
curlywas/src/typecheck.rs

681 lines
21 KiB
Rust

use ariadne::{Color, Label, Report, ReportKind, Source};
use std::collections::HashMap;
use crate::ast;
use crate::Span;
use ast::Type::*;
type Result<T> = std::result::Result<T, ()>;
struct Var {
span: Span,
type_: ast::Type,
}
type Vars = HashMap<String, Var>;
pub fn tc_script(script: &mut ast::Script, source: &str) -> Result<()> {
let mut context = Context {
source,
global_vars: HashMap::new(),
functions: HashMap::new(),
local_vars: HashMap::new(),
block_stack: Vec::new(),
return_type: None,
};
let mut result = Ok(());
for import in &script.imports {
match import.type_ {
ast::ImportType::Variable {
ref name, type_, ..
} => {
if let Some(Var { span, .. }) = context.global_vars.get(name) {
result = report_duplicate_definition(
"Global already defined",
&import.span,
span,
source,
);
} else {
context.global_vars.insert(
name.clone(),
Var {
type_,
span: import.span.clone(),
},
);
}
}
ast::ImportType::Function {
ref name,
ref params,
result: ref result_type,
} => {
if let Some(fnc) = context.functions.get(name) {
result = report_duplicate_definition(
"Function already defined",
&import.span,
&fnc.span,
source,
);
} else {
context.functions.insert(
name.clone(),
FunctionType {
span: import.span.clone(),
params: params.clone(),
type_: *result_type,
},
);
}
}
ast::ImportType::Memory(..) => (),
}
}
for v in &script.global_vars {
if let Some(Var { span, .. }) = context.global_vars.get(&v.name) {
result = report_duplicate_definition("Global already defined", &v.span, span, source);
} else {
context.global_vars.insert(
v.name.clone(),
Var {
type_: v.type_,
span: v.span.clone(),
},
);
}
}
for f in &script.functions {
let params = f.params.iter().map(|(_, t)| *t).collect();
if let Some(fnc) = context.functions.get(&f.name) {
result =
report_duplicate_definition("Function already defined", &f.span, &fnc.span, source);
} else {
context.functions.insert(
f.name.clone(),
FunctionType {
params,
type_: f.type_,
span: f.span.clone(),
},
);
}
}
for f in &mut script.functions {
context.local_vars.clear();
for (name, type_) in &f.params {
if let Some(Var { span, .. }) = context
.local_vars
.get(name)
.or_else(|| context.global_vars.get(name))
{
result =
report_duplicate_definition("Variable already defined", &f.span, span, source);
} else {
context.local_vars.insert(
name.clone(),
Var {
type_: *type_,
span: f.span.clone(),
},
);
}
}
context.return_type = f.type_;
tc_expression(&mut context, &mut f.body)?;
if f.body.type_ != f.type_ {
result = type_mismatch(f.type_, &f.span, f.body.type_, &f.body.span, source);
}
}
result
}
struct FunctionType {
span: Span,
params: Vec<ast::Type>,
type_: Option<ast::Type>,
}
struct Context<'a> {
source: &'a str,
global_vars: Vars,
functions: HashMap<String, FunctionType>,
local_vars: Vars,
block_stack: Vec<String>,
return_type: Option<ast::Type>,
}
fn report_duplicate_definition(
msg: &str,
span: &Span,
prev_span: &Span,
source: &str,
) -> Result<()> {
Report::build(ReportKind::Error, (), span.start)
.with_message(msg)
.with_label(
Label::new(span.clone())
.with_message(msg)
.with_color(Color::Red),
)
.with_label(
Label::new(prev_span.clone())
.with_message("Previous definition was here")
.with_color(Color::Yellow),
)
.finish()
.eprint(Source::from(source))
.unwrap();
Err(())
}
fn type_mismatch(
type1: Option<ast::Type>,
span1: &Span,
type2: Option<ast::Type>,
span2: &Span,
source: &str,
) -> Result<()> {
Report::build(ReportKind::Error, (), span2.start)
.with_message("Type mismatch")
.with_label(
Label::new(span1.clone())
.with_message(format!(
"Expected type {:?}...",
type1
.map(|t| format!("{:?}", t))
.unwrap_or("void".to_string())
))
.with_color(Color::Yellow),
)
.with_label(
Label::new(span2.clone())
.with_message(format!(
"...but found type {}",
type2
.map(|t| format!("{:?}", t))
.unwrap_or("void".to_string())
))
.with_color(Color::Red),
)
.finish()
.eprint(Source::from(source))
.unwrap();
Err(())
}
fn expected_type(span: &Span, source: &str) -> Result<()> {
Report::build(ReportKind::Error, (), span.start)
.with_message("Expected value but found expression of type void")
.with_label(
Label::new(span.clone())
.with_message("Expected value but found expression of type void")
.with_color(Color::Red),
)
.finish()
.eprint(Source::from(source))
.unwrap();
Err(())
}
fn unknown_variable(span: &Span, source: &str) -> Result<()> {
Report::build(ReportKind::Error, (), span.start)
.with_message("Unknown variable")
.with_label(
Label::new(span.clone())
.with_message("Unknown variable")
.with_color(Color::Red),
)
.finish()
.eprint(Source::from(source))
.unwrap();
Err(())
}
fn missing_label(span: &Span, source: &str) -> Result<()> {
Report::build(ReportKind::Error, (), span.start)
.with_message("Label not found")
.with_label(
Label::new(span.clone())
.with_message("Label not found")
.with_color(Color::Red),
)
.finish()
.eprint(Source::from(source))
.unwrap();
return Err(());
}
fn tc_expression(context: &mut Context, expr: &mut ast::Expression) -> Result<()> {
expr.type_ = match expr.expr {
ast::Expr::Block {
ref mut statements,
ref mut final_expression,
} => {
for stmt in statements {
tc_expression(context, stmt)?;
}
if let Some(final_expression) = final_expression {
tc_expression(context, final_expression)?;
final_expression.type_
} else {
None
}
}
ast::Expr::Let {
ref mut value,
ref mut type_,
ref name,
..
} => {
if let Some(ref mut value) = value {
tc_expression(context, value)?;
if let Some(type_) = type_ {
if Some(*type_) != value.type_ {
return type_mismatch(
Some(*type_),
&expr.span,
value.type_,
&value.span,
context.source,
);
}
} else if value.type_.is_none() {
return expected_type(&value.span, context.source);
} else {
*type_ = value.type_;
}
}
if let Some(type_) = type_ {
if let Some(Var { span, .. }) = context
.local_vars
.get(name)
.or_else(|| context.global_vars.get(name))
{
return report_duplicate_definition(
"Variable already defined",
&expr.span,
span,
context.source,
);
}
context.local_vars.insert(
name.clone(),
Var {
type_: *type_,
span: expr.span.clone(),
},
);
} else {
Report::build(ReportKind::Error, (), expr.span.start)
.with_message("Type missing")
.with_label(
Label::new(expr.span.clone())
.with_message("Type missing")
.with_color(Color::Red),
)
.finish()
.eprint(Source::from(context.source))
.unwrap();
return Err(());
}
None
}
ast::Expr::Peek(ref mut mem_location) => {
tc_mem_location(context, mem_location)?;
Some(I32)
}
ast::Expr::Poke {
ref mut mem_location,
ref mut value,
} => {
tc_mem_location(context, mem_location)?;
tc_expression(context, value)?;
if value.type_ != Some(I32) {
return type_mismatch(
Some(I32),
&expr.span,
value.type_,
&value.span,
context.source,
);
}
None
}
ast::Expr::I32Const(_) => Some(ast::Type::I32),
ast::Expr::F32Const(_) => Some(ast::Type::F32),
ast::Expr::UnaryOp {
op: _,
ref mut value,
} => {
tc_expression(context, value)?;
todo!();
}
ast::Expr::BinOp {
op,
ref mut left,
ref mut right,
} => {
tc_expression(context, left)?;
tc_expression(context, right)?;
if let Some(type_) = left.type_ {
if left.type_ != right.type_ {
return type_mismatch(
Some(type_),
&left.span,
right.type_,
&right.span,
context.source,
);
}
} else {
return expected_type(&left.span, context.source);
}
use ast::BinOp::*;
match op {
Add | Sub | Mul | Div => left.type_,
Rem | And | Or | Xor | Lsl | Lsr | Asr => {
if left.type_ != Some(I32) {
return type_mismatch(
Some(I32),
&left.span,
left.type_,
&left.span,
context.source,
);
} else {
left.type_
}
}
Eq | Ne | Lt | Le | Gt | Ge => Some(I32),
}
}
ast::Expr::Variable(ref name) => {
if let Some(&Var { type_, .. }) = context
.global_vars
.get(name)
.or_else(|| context.local_vars.get(name))
{
Some(type_)
} else {
return unknown_variable(&expr.span, context.source);
}
}
ast::Expr::Assign {
ref name,
ref mut value,
} => {
tc_expression(context, value)?;
if let Some(&Var {
type_, ref span, ..
}) = context
.local_vars
.get(name)
.or_else(|| context.global_vars.get(name))
{
if value.type_ != Some(type_) {
return type_mismatch(
Some(type_),
span,
value.type_,
&value.span,
context.source,
);
}
} else {
return unknown_variable(&expr.span, context.source);
}
None
}
ast::Expr::LocalTee {
ref name,
ref mut value,
} => {
tc_expression(context, value)?;
if let Some(&Var {
type_, ref span, ..
}) = context.local_vars.get(name)
{
if value.type_ != Some(type_) {
return type_mismatch(
Some(type_),
span,
value.type_,
&value.span,
context.source,
);
}
Some(type_)
} else {
return unknown_variable(&expr.span, context.source);
}
}
ast::Expr::Loop {
ref label,
ref mut block,
} => {
context.block_stack.push(label.clone());
tc_expression(context, block)?;
context.block_stack.pop();
block.type_
}
ast::Expr::Branch(ref label) => {
if !context.block_stack.contains(label) {
return missing_label(&expr.span, context.source);
}
None
}
ast::Expr::BranchIf {
ref mut condition,
ref label,
} => {
tc_expression(context, condition)?;
if condition.type_ != Some(I32) {
return type_mismatch(
Some(I32),
&expr.span,
condition.type_,
&condition.span,
context.source,
);
}
if !context.block_stack.contains(label) {
return missing_label(&expr.span, context.source);
}
None
}
ast::Expr::Cast {
ref mut value,
type_,
} => {
tc_expression(context, value)?;
if value.type_.is_none() {
return expected_type(&expr.span, context.source);
}
Some(type_)
}
ast::Expr::FuncCall {
ref name,
ref mut params,
} => {
for param in params.iter_mut() {
tc_expression(context, param)?;
}
if let Some((ptypes, rtype)) = context
.functions
.get(name)
.map(|fnc| (fnc.params.as_slice(), fnc.type_))
.or_else(|| builtin_function_types(name))
{
if params.len() != ptypes.len() {
Report::build(ReportKind::Error, (), expr.span.start)
.with_message(format!(
"Expected {} parameters but found {}",
ptypes.len(),
params.len()
))
.with_label(
Label::new(expr.span.clone())
.with_message(format!(
"Expected {} parameters but found {}",
ptypes.len(),
params.len()
))
.with_color(Color::Red),
)
.finish()
.eprint(Source::from(context.source))
.unwrap();
return Err(());
}
for (ptype, param) in ptypes.iter().zip(params.iter()) {
if param.type_ != Some(*ptype) {
return type_mismatch(
Some(*ptype),
&expr.span,
param.type_,
&param.span,
context.source,
);
}
}
rtype
} else {
Report::build(ReportKind::Error, (), expr.span.start)
.with_message(format!("Unknown function {}", name))
.with_label(
Label::new(expr.span.clone())
.with_message(format!("Unknown function {}", name))
.with_color(Color::Red),
)
.finish()
.eprint(Source::from(context.source))
.unwrap();
return Err(());
}
}
ast::Expr::Select {
ref mut condition,
ref mut if_true,
ref mut if_false,
} => {
tc_expression(context, condition)?;
tc_expression(context, if_true)?;
tc_expression(context, if_false)?;
if condition.type_ != Some(ast::Type::I32) {
return type_mismatch(
Some(I32),
&condition.span,
condition.type_,
&condition.span,
context.source,
);
}
if if_true.type_.is_some() {
if if_true.type_ != if_false.type_ {
return type_mismatch(
if_true.type_,
&if_true.span,
if_false.type_,
&if_false.span,
context.source,
);
}
} else {
return expected_type(&if_true.span, context.source);
}
if_true.type_
}
ast::Expr::If {
ref mut condition,
ref mut if_true,
ref mut if_false,
} => {
tc_expression(context, condition)?;
tc_expression(context, if_true)?;
if let Some(ref mut if_false) = if_false {
tc_expression(context, if_false)?;
if if_true.type_ != if_false.type_ {
return type_mismatch(
if_true.type_,
&if_true.span,
if_false.type_,
&if_false.span,
context.source,
);
} else {
if_true.type_
}
} else {
None
}
}
ast::Expr::Return { ref mut value } => {
if let Some(ref mut value) = value {
tc_expression(context, value)?;
if value.type_ != context.return_type {
return type_mismatch(
context.return_type,
&expr.span,
value.type_,
&value.span,
context.source,
);
}
}
None
}
ast::Expr::Error => unreachable!(),
};
Ok(())
}
fn tc_mem_location<'a>(
context: &mut Context<'a>,
mem_location: &mut ast::MemoryLocation,
) -> Result<()> {
tc_expression(context, &mut mem_location.left)?;
tc_expression(context, &mut mem_location.right)?;
if mem_location.left.type_ != Some(I32) {
return type_mismatch(
Some(I32),
&mem_location.left.span,
mem_location.left.type_,
&mem_location.left.span,
context.source,
);
}
if let ast::Expr::I32Const(_) = mem_location.right.expr {
} else {
Report::build(ReportKind::Error, (), mem_location.right.span.start)
.with_message("Expected I32 constant")
.with_label(
Label::new(mem_location.right.span.clone())
.with_message("Expected I32 constant")
.with_color(Color::Red),
)
.finish()
.eprint(Source::from(context.source))
.unwrap();
return Err(());
}
Ok(())
}
fn builtin_function_types(name: &str) -> Option<(&'static [ast::Type], Option<ast::Type>)> {
use ast::Type::*;
let types: (&'static [ast::Type], Option<ast::Type>) = match name {
"sqrt" => (&[F32], Some(F32)),
"abs" => (&[F32], Some(F32)),
_ => return None,
};
Some(types)
}