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core: Add compile-time error and runtime assertion for negative shifts

This commit is contained in:
David Mak 2023-11-02 16:04:55 +08:00 committed by sb10q
parent 1ca4de99b9
commit 3231eb0d78
2 changed files with 56 additions and 4 deletions
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39
nac3core/src/codegen/expr.rs
View File

@ -298,8 +298,40 @@ impl<'ctx, 'a> CodeGenContext<'ctx, 'a> {
(Operator::BitOr, _) => self.builder.build_or(lhs, rhs, "or").into(),
(Operator::BitXor, _) => self.builder.build_xor(lhs, rhs, "xor").into(),
(Operator::BitAnd, _) => self.builder.build_and(lhs, rhs, "and").into(),
(Operator::LShift, _) => self.builder.build_left_shift(lhs, rhs, "lshift").into(),
(Operator::RShift, _) => self.builder.build_right_shift(lhs, rhs, true, "rshift").into(),
// Sign-ness of bitshift operators are always determined by the left operand
(Operator::LShift, signed) | (Operator::RShift, signed) => {
// RHS operand is always 32 bits
assert_eq!(rhs.get_type().get_bit_width(), 32);
let common_type = lhs.get_type();
let rhs = if common_type.get_bit_width() > 32 {
if signed {
self.builder.build_int_s_extend(rhs, common_type, "")
} else {
self.builder.build_int_z_extend(rhs, common_type, "")
}
} else {
rhs
};
let rhs_gez = self.builder.build_int_compare(IntPredicate::SGE, rhs, common_type.const_zero(), "");
self.make_assert(
generator,
rhs_gez,
"ValueError",
"negative shift count",
[None, None, None],
self.current_loc
);
match *op {
Operator::LShift => self.builder.build_left_shift(lhs, rhs, "lshift").into(),
Operator::RShift => self.builder.build_right_shift(lhs, rhs, signed, "rshift").into(),
_ => unreachable!()
}
}
(Operator::FloorDiv, true) => self.builder.build_int_signed_div(lhs, rhs, "floordiv").into(),
(Operator::FloorDiv, false) => self.builder.build_int_unsigned_div(lhs, rhs, "floordiv").into(),
(Operator::Pow, s) => integer_power(generator, self, lhs, rhs, s).into(),
@ -1085,6 +1117,9 @@ pub fn gen_binop_expr<'ctx, 'a, G: CodeGenerator>(
Ok(Some(ctx.gen_int_ops(generator, op, left_val, right_val, true).into()))
} else if ty1 == ty2 && [ctx.primitives.uint32, ctx.primitives.uint64].contains(&ty1) {
Ok(Some(ctx.gen_int_ops(generator, op, left_val, right_val, false).into()))
} else if [Operator::LShift, Operator::RShift].contains(op) {
let signed = [ctx.primitives.int32, ctx.primitives.int64].contains(&ty1);
Ok(Some(ctx.gen_int_ops(generator, op, left_val, right_val, signed).into()))
} else if ty1 == ty2 && ctx.primitives.float == ty1 {
Ok(Some(ctx.gen_float_ops(op, left_val, right_val).into()))
} else if ty1 == ctx.primitives.float && ty2 == ctx.primitives.int32 {

21
nac3core/src/typecheck/function_check.rs
View File

@ -2,7 +2,7 @@ use crate::typecheck::typedef::TypeEnum;
use super::type_inferencer::Inferencer;
use super::typedef::Type;
use nac3parser::ast::{self, Expr, ExprKind, Stmt, StmtKind, StrRef};
use nac3parser::ast::{self, Constant, Expr, ExprKind, Operator::{LShift, RShift}, Stmt, StmtKind, StrRef};
use std::{collections::HashSet, iter::once};
impl<'a> Inferencer<'a> {
@ -107,11 +107,28 @@ impl<'a> Inferencer<'a> {
self.check_expr(value, defined_identifiers)?;
self.should_have_value(value)?;
}
ExprKind::BinOp { left, right, .. } => {
ExprKind::BinOp { left, op, right } => {
self.check_expr(left, defined_identifiers)?;
self.check_expr(right, defined_identifiers)?;
self.should_have_value(left)?;
self.should_have_value(right)?;
// Check whether a bitwise shift has a negative RHS constant value
if *op == LShift || *op == RShift {
if let ExprKind::Constant { value, .. } = &right.node {
let rhs_val = match value {
Constant::Int(v) => v,
_ => unreachable!(),
};
if *rhs_val < 0 {
return Err(format!(
"shift count is negative at {}",
right.location
));
}
}
}
}
ExprKind::UnaryOp { operand, .. } => {
self.check_expr(operand, defined_identifiers)?;