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use std::num::NonZeroU32;
use crate::{
front::glsl::{
ast::{FunctionCall, FunctionCallKind, HirExpr, HirExprKind},
context::{Context, StmtContext},
error::{ErrorKind, ExpectedToken},
parser::ParsingContext,
token::{Token, TokenValue},
Error, Frontend, Result, Span,
},
ArraySize, BinaryOperator, Handle, Literal, Type, TypeInner, UnaryOperator,
};
impl<'source> ParsingContext<'source> {
pub fn parse_primary(
&mut self,
frontend: &mut Frontend,
ctx: &mut Context,
stmt: &mut StmtContext,
) -> Result<Handle<HirExpr>> {
let mut token = self.bump(frontend)?;
let literal = match token.value {
TokenValue::IntConstant(int) => {
if int.width != 32 {
frontend.errors.push(Error {
kind: ErrorKind::SemanticError("Unsupported non-32bit integer".into()),
meta: token.meta,
});
}
if int.signed {
Literal::I32(int.value as i32)
} else {
Literal::U32(int.value as u32)
}
}
TokenValue::FloatConstant(float) => {
if float.width != 32 {
frontend.errors.push(Error {
kind: ErrorKind::SemanticError(
concat!(
"Unsupported floating-point value ",
"(expected single-precision floating-point number)"
)
.into(),
),
meta: token.meta,
});
}
Literal::F32(float.value)
}
TokenValue::BoolConstant(value) => Literal::Bool(value),
TokenValue::LeftParen => {
let expr = self.parse_expression(frontend, ctx, stmt)?;
let meta = self.expect(frontend, TokenValue::RightParen)?.meta;
token.meta.subsume(meta);
return Ok(expr);
}
_ => {
return Err(Error {
kind: ErrorKind::InvalidToken(
token.value,
vec![
TokenValue::LeftParen.into(),
ExpectedToken::IntLiteral,
ExpectedToken::FloatLiteral,
ExpectedToken::BoolLiteral,
],
),
meta: token.meta,
});
}
};
Ok(stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::Literal(literal),
meta: token.meta,
},
Default::default(),
))
}
pub fn parse_function_call_args(
&mut self,
frontend: &mut Frontend,
ctx: &mut Context,
stmt: &mut StmtContext,
meta: &mut Span,
) -> Result<Vec<Handle<HirExpr>>> {
let mut args = Vec::new();
if let Some(token) = self.bump_if(frontend, TokenValue::RightParen) {
meta.subsume(token.meta);
} else {
loop {
args.push(self.parse_assignment(frontend, ctx, stmt)?);
let token = self.bump(frontend)?;
match token.value {
TokenValue::Comma => {}
TokenValue::RightParen => {
meta.subsume(token.meta);
break;
}
_ => {
return Err(Error {
kind: ErrorKind::InvalidToken(
token.value,
vec![TokenValue::Comma.into(), TokenValue::RightParen.into()],
),
meta: token.meta,
});
}
}
}
}
Ok(args)
}
pub fn parse_postfix(
&mut self,
frontend: &mut Frontend,
ctx: &mut Context,
stmt: &mut StmtContext,
) -> Result<Handle<HirExpr>> {
let mut base = if self.peek_type_name(frontend) {
let (mut handle, mut meta) = self.parse_type_non_void(frontend, ctx)?;
self.expect(frontend, TokenValue::LeftParen)?;
let args = self.parse_function_call_args(frontend, ctx, stmt, &mut meta)?;
if let TypeInner::Array {
size: ArraySize::Dynamic,
stride,
base,
} = ctx.module.types[handle].inner
{
let span = ctx.module.types.get_span(handle);
let size = u32::try_from(args.len())
.ok()
.and_then(NonZeroU32::new)
.ok_or(Error {
kind: ErrorKind::SemanticError(
"There must be at least one argument".into(),
),
meta,
})?;
handle = ctx.module.types.insert(
Type {
name: None,
inner: TypeInner::Array {
stride,
base,
size: ArraySize::Constant(size),
},
},
span,
)
}
stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::Call(FunctionCall {
kind: FunctionCallKind::TypeConstructor(handle),
args,
}),
meta,
},
Default::default(),
)
} else if let TokenValue::Identifier(_) = self.expect_peek(frontend)?.value {
let (name, mut meta) = self.expect_ident(frontend)?;
let expr = if self.bump_if(frontend, TokenValue::LeftParen).is_some() {
let args = self.parse_function_call_args(frontend, ctx, stmt, &mut meta)?;
let kind = match frontend.lookup_type.get(&name) {
Some(ty) => FunctionCallKind::TypeConstructor(*ty),
None => FunctionCallKind::Function(name),
};
HirExpr {
kind: HirExprKind::Call(FunctionCall { kind, args }),
meta,
}
} else {
let var = match frontend.lookup_variable(ctx, &name, meta)? {
Some(var) => var,
None => {
return Err(Error {
kind: ErrorKind::UnknownVariable(name),
meta,
})
}
};
HirExpr {
kind: HirExprKind::Variable(var),
meta,
}
};
stmt.hir_exprs.append(expr, Default::default())
} else {
self.parse_primary(frontend, ctx, stmt)?
};
while let TokenValue::LeftBracket
| TokenValue::Dot
| TokenValue::Increment
| TokenValue::Decrement = self.expect_peek(frontend)?.value
{
let Token { value, mut meta } = self.bump(frontend)?;
match value {
TokenValue::LeftBracket => {
let index = self.parse_expression(frontend, ctx, stmt)?;
let end_meta = self.expect(frontend, TokenValue::RightBracket)?.meta;
meta.subsume(end_meta);
base = stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::Access { base, index },
meta,
},
Default::default(),
)
}
TokenValue::Dot => {
let (field, end_meta) = self.expect_ident(frontend)?;
if self.bump_if(frontend, TokenValue::LeftParen).is_some() {
let args = self.parse_function_call_args(frontend, ctx, stmt, &mut meta)?;
base = stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::Method {
expr: base,
name: field,
args,
},
meta,
},
Default::default(),
);
continue;
}
meta.subsume(end_meta);
base = stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::Select { base, field },
meta,
},
Default::default(),
)
}
TokenValue::Increment | TokenValue::Decrement => {
base = stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::PrePostfix {
op: match value {
TokenValue::Increment => BinaryOperator::Add,
_ => BinaryOperator::Subtract,
},
postfix: true,
expr: base,
},
meta,
},
Default::default(),
)
}
_ => unreachable!(),
}
}
Ok(base)
}
pub fn parse_unary(
&mut self,
frontend: &mut Frontend,
ctx: &mut Context,
stmt: &mut StmtContext,
) -> Result<Handle<HirExpr>> {
Ok(match self.expect_peek(frontend)?.value {
TokenValue::Plus | TokenValue::Dash | TokenValue::Bang | TokenValue::Tilde => {
let Token { value, mut meta } = self.bump(frontend)?;
let expr = self.parse_unary(frontend, ctx, stmt)?;
let end_meta = stmt.hir_exprs[expr].meta;
let kind = match value {
TokenValue::Dash => HirExprKind::Unary {
op: UnaryOperator::Negate,
expr,
},
TokenValue::Bang => HirExprKind::Unary {
op: UnaryOperator::LogicalNot,
expr,
},
TokenValue::Tilde => HirExprKind::Unary {
op: UnaryOperator::BitwiseNot,
expr,
},
_ => return Ok(expr),
};
meta.subsume(end_meta);
stmt.hir_exprs
.append(HirExpr { kind, meta }, Default::default())
}
TokenValue::Increment | TokenValue::Decrement => {
let Token { value, meta } = self.bump(frontend)?;
let expr = self.parse_unary(frontend, ctx, stmt)?;
stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::PrePostfix {
op: match value {
TokenValue::Increment => BinaryOperator::Add,
_ => BinaryOperator::Subtract,
},
postfix: false,
expr,
},
meta,
},
Default::default(),
)
}
_ => self.parse_postfix(frontend, ctx, stmt)?,
})
}
pub fn parse_binary(
&mut self,
frontend: &mut Frontend,
ctx: &mut Context,
stmt: &mut StmtContext,
passthrough: Option<Handle<HirExpr>>,
min_bp: u8,
) -> Result<Handle<HirExpr>> {
let mut left = passthrough
.ok_or(ErrorKind::EndOfFile /* Dummy error */)
.or_else(|_| self.parse_unary(frontend, ctx, stmt))?;
let mut meta = stmt.hir_exprs[left].meta;
while let Some((l_bp, r_bp)) = binding_power(&self.expect_peek(frontend)?.value) {
if l_bp < min_bp {
break;
}
let Token { value, .. } = self.bump(frontend)?;
let right = self.parse_binary(frontend, ctx, stmt, None, r_bp)?;
let end_meta = stmt.hir_exprs[right].meta;
meta.subsume(end_meta);
left = stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::Binary {
left,
op: match value {
TokenValue::LogicalOr => BinaryOperator::LogicalOr,
TokenValue::LogicalXor => BinaryOperator::NotEqual,
TokenValue::LogicalAnd => BinaryOperator::LogicalAnd,
TokenValue::VerticalBar => BinaryOperator::InclusiveOr,
TokenValue::Caret => BinaryOperator::ExclusiveOr,
TokenValue::Ampersand => BinaryOperator::And,
TokenValue::Equal => BinaryOperator::Equal,
TokenValue::NotEqual => BinaryOperator::NotEqual,
TokenValue::GreaterEqual => BinaryOperator::GreaterEqual,
TokenValue::LessEqual => BinaryOperator::LessEqual,
TokenValue::LeftAngle => BinaryOperator::Less,
TokenValue::RightAngle => BinaryOperator::Greater,
TokenValue::LeftShift => BinaryOperator::ShiftLeft,
TokenValue::RightShift => BinaryOperator::ShiftRight,
TokenValue::Plus => BinaryOperator::Add,
TokenValue::Dash => BinaryOperator::Subtract,
TokenValue::Star => BinaryOperator::Multiply,
TokenValue::Slash => BinaryOperator::Divide,
TokenValue::Percent => BinaryOperator::Modulo,
_ => unreachable!(),
},
right,
},
meta,
},
Default::default(),
)
}
Ok(left)
}
pub fn parse_conditional(
&mut self,
frontend: &mut Frontend,
ctx: &mut Context,
stmt: &mut StmtContext,
passthrough: Option<Handle<HirExpr>>,
) -> Result<Handle<HirExpr>> {
let mut condition = self.parse_binary(frontend, ctx, stmt, passthrough, 0)?;
let mut meta = stmt.hir_exprs[condition].meta;
if self.bump_if(frontend, TokenValue::Question).is_some() {
let accept = self.parse_expression(frontend, ctx, stmt)?;
self.expect(frontend, TokenValue::Colon)?;
let reject = self.parse_assignment(frontend, ctx, stmt)?;
let end_meta = stmt.hir_exprs[reject].meta;
meta.subsume(end_meta);
condition = stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::Conditional {
condition,
accept,
reject,
},
meta,
},
Default::default(),
)
}
Ok(condition)
}
pub fn parse_assignment(
&mut self,
frontend: &mut Frontend,
ctx: &mut Context,
stmt: &mut StmtContext,
) -> Result<Handle<HirExpr>> {
let tgt = self.parse_unary(frontend, ctx, stmt)?;
let mut meta = stmt.hir_exprs[tgt].meta;
Ok(match self.expect_peek(frontend)?.value {
TokenValue::Assign => {
self.bump(frontend)?;
let value = self.parse_assignment(frontend, ctx, stmt)?;
let end_meta = stmt.hir_exprs[value].meta;
meta.subsume(end_meta);
stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::Assign { tgt, value },
meta,
},
Default::default(),
)
}
TokenValue::OrAssign
| TokenValue::AndAssign
| TokenValue::AddAssign
| TokenValue::DivAssign
| TokenValue::ModAssign
| TokenValue::SubAssign
| TokenValue::MulAssign
| TokenValue::LeftShiftAssign
| TokenValue::RightShiftAssign
| TokenValue::XorAssign => {
let token = self.bump(frontend)?;
let right = self.parse_assignment(frontend, ctx, stmt)?;
let end_meta = stmt.hir_exprs[right].meta;
meta.subsume(end_meta);
let value = stmt.hir_exprs.append(
HirExpr {
meta,
kind: HirExprKind::Binary {
left: tgt,
op: match token.value {
TokenValue::OrAssign => BinaryOperator::InclusiveOr,
TokenValue::AndAssign => BinaryOperator::And,
TokenValue::AddAssign => BinaryOperator::Add,
TokenValue::DivAssign => BinaryOperator::Divide,
TokenValue::ModAssign => BinaryOperator::Modulo,
TokenValue::SubAssign => BinaryOperator::Subtract,
TokenValue::MulAssign => BinaryOperator::Multiply,
TokenValue::LeftShiftAssign => BinaryOperator::ShiftLeft,
TokenValue::RightShiftAssign => BinaryOperator::ShiftRight,
TokenValue::XorAssign => BinaryOperator::ExclusiveOr,
_ => unreachable!(),
},
right,
},
},
Default::default(),
);
stmt.hir_exprs.append(
HirExpr {
kind: HirExprKind::Assign { tgt, value },
meta,
},
Default::default(),
)
}
_ => self.parse_conditional(frontend, ctx, stmt, Some(tgt))?,
})
}
pub fn parse_expression(
&mut self,
frontend: &mut Frontend,
ctx: &mut Context,
stmt: &mut StmtContext,
) -> Result<Handle<HirExpr>> {
let mut expr = self.parse_assignment(frontend, ctx, stmt)?;
while let TokenValue::Comma = self.expect_peek(frontend)?.value {
self.bump(frontend)?;
expr = self.parse_assignment(frontend, ctx, stmt)?;
}
Ok(expr)
}
}
const fn binding_power(value: &TokenValue) -> Option<(u8, u8)> {
Some(match *value {
TokenValue::LogicalOr => (1, 2),
TokenValue::LogicalXor => (3, 4),
TokenValue::LogicalAnd => (5, 6),
TokenValue::VerticalBar => (7, 8),
TokenValue::Caret => (9, 10),
TokenValue::Ampersand => (11, 12),
TokenValue::Equal | TokenValue::NotEqual => (13, 14),
TokenValue::GreaterEqual
| TokenValue::LessEqual
| TokenValue::LeftAngle
| TokenValue::RightAngle => (15, 16),
TokenValue::LeftShift | TokenValue::RightShift => (17, 18),
TokenValue::Plus | TokenValue::Dash => (19, 20),
TokenValue::Star | TokenValue::Slash | TokenValue::Percent => (21, 22),
_ => return None,
})
}