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cranelift: Emit a trap when dividing by zero in interpreter

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Fixes #3058
This commit is contained in:
Afonso Bordado
2021-07-21 14:43:01 +01:00
committed by Andrew Brown
parent 6be4441bbf
commit df48798396
3 changed files with 71 additions and 18 deletions
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47
cranelift/interpreter/src/step.rs
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@@ -72,6 +72,15 @@ where
// Indicate that the result of a step is to assign a single value to an instruction's results.
let assign = |value: V| ControlFlow::Assign(smallvec![value]);
// Similar to `assign` but converts some errors into traps
let assign_or_trap = |value: ValueResult<V>| match value {
Ok(v) => Ok(assign(v)),
Err(ValueError::IntegerDivisionByZero) => Ok(ControlFlow::Trap(CraneliftTrap::User(
TrapCode::IntegerDivisionByZero,
))),
Err(e) => Err(e),
};
// Interpret a binary instruction with the given `op`, assigning the resulting value to the
// instruction's results.
let binary = |op: fn(V, V) -> ValueResult<V>,
@@ -79,18 +88,24 @@ where
right: V|
-> ValueResult<ControlFlow<V>> { Ok(assign(op(left, right)?)) };
// Same as `binary`, but converts the values to their unsigned form before the operation and
// back to signed form afterwards. Since Cranelift types have no notion of signedness, this
// enables operations that depend on sign.
let binary_unsigned =
// Similar to `binary` but converts select `ValueError`'s into trap `ControlFlow`'s
let binary_can_trap = |op: fn(V, V) -> ValueResult<V>,
left: V,
right: V|
-> ValueResult<ControlFlow<V>> { assign_or_trap(op(left, right)) };
// Same as `binary_can_trap`, but converts the values to their unsigned form before the
// operation and back to signed form afterwards. Since Cranelift types have no notion of
// signedness, this enables operations that depend on sign.
let binary_unsigned_can_trap =
|op: fn(V, V) -> ValueResult<V>, left: V, right: V| -> ValueResult<ControlFlow<V>> {
Ok(assign(
assign_or_trap(
op(
left.convert(ValueConversionKind::ToUnsigned)?,
right.convert(ValueConversionKind::ToUnsigned)?,
)?
.convert(ValueConversionKind::ToSigned)?,
))
)
.and_then(|v| v.convert(ValueConversionKind::ToSigned)),
)
};
// Choose whether to assign `left` or `right` to the instruction's result based on a `condition`.
@@ -425,16 +440,16 @@ where
Opcode::Imul => binary(Value::mul, arg(0)?, arg(1)?)?,
Opcode::Umulhi => unimplemented!("Umulhi"),
Opcode::Smulhi => unimplemented!("Smulhi"),
Opcode::Udiv => binary_unsigned(Value::div, arg(0)?, arg(1)?)?,
Opcode::Sdiv => binary(Value::div, arg(0)?, arg(1)?)?,
Opcode::Urem => binary_unsigned(Value::rem, arg(0)?, arg(1)?)?,
Opcode::Srem => binary(Value::rem, arg(0)?, arg(1)?)?,
Opcode::Udiv => binary_unsigned_can_trap(Value::div, arg(0)?, arg(1)?)?,
Opcode::Sdiv => binary_can_trap(Value::div, arg(0)?, arg(1)?)?,
Opcode::Urem => binary_unsigned_can_trap(Value::rem, arg(0)?, arg(1)?)?,
Opcode::Srem => binary_can_trap(Value::rem, arg(0)?, arg(1)?)?,
Opcode::IaddImm => binary(Value::add, arg(0)?, imm_as_ctrl_ty()?)?,
Opcode::ImulImm => binary(Value::mul, arg(0)?, imm_as_ctrl_ty()?)?,
Opcode::UdivImm => binary_unsigned(Value::div, arg(0)?, imm())?,
Opcode::SdivImm => binary(Value::div, arg(0)?, imm_as_ctrl_ty()?)?,
Opcode::UremImm => binary_unsigned(Value::rem, arg(0)?, imm())?,
Opcode::SremImm => binary(Value::rem, arg(0)?, imm_as_ctrl_ty()?)?,
Opcode::UdivImm => binary_unsigned_can_trap(Value::div, arg(0)?, imm())?,
Opcode::SdivImm => binary_can_trap(Value::div, arg(0)?, imm_as_ctrl_ty()?)?,
Opcode::UremImm => binary_unsigned_can_trap(Value::rem, arg(0)?, imm())?,
Opcode::SremImm => binary_can_trap(Value::rem, arg(0)?, imm_as_ctrl_ty()?)?,
Opcode::IrsubImm => binary(Value::sub, imm_as_ctrl_ty()?, arg(0)?)?,
Opcode::IaddCin => unimplemented!("IaddCin"),
Opcode::IaddIfcin => unimplemented!("IaddIfcin"),