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fix: Add size checks to integer literals (#3236)
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jfecher authored and guipublic committed Oct 26, 2023
1 parent 3302523 commit 4248a87
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Showing 12 changed files with 259 additions and 155 deletions.
7 changes: 5 additions & 2 deletions compiler/noirc_evaluator/src/errors.rs
Original file line number Diff line number Diff line change
Expand Up @@ -7,12 +7,12 @@
//! An Error of the former is a user Error
//!
//! An Error of the latter is an error in the implementation of the compiler
use acvm::acir::native_types::Expression;
use acvm::{acir::native_types::Expression, FieldElement};
use iter_extended::vecmap;
use noirc_errors::{CustomDiagnostic as Diagnostic, FileDiagnostic};
use thiserror::Error;

use crate::ssa::ir::dfg::CallStack;
use crate::ssa::ir::{dfg::CallStack, types::NumericType};

#[derive(Debug, PartialEq, Eq, Clone, Error)]
pub enum RuntimeError {
Expand All @@ -29,6 +29,8 @@ pub enum RuntimeError {
IndexOutOfBounds { index: usize, array_size: usize, call_stack: CallStack },
#[error("Range constraint of {num_bits} bits is too large for the Field size")]
InvalidRangeConstraint { num_bits: u32, call_stack: CallStack },
#[error("{value} does not fit within the type bounds for {typ}")]
IntegerOutOfBounds { value: FieldElement, typ: NumericType, call_stack: CallStack },
#[error("Expected array index to fit into a u64")]
TypeConversion { from: String, into: String, call_stack: CallStack },
#[error("{name:?} is not initialized")]
Expand Down Expand Up @@ -91,6 +93,7 @@ impl RuntimeError {
| RuntimeError::UnInitialized { call_stack, .. }
| RuntimeError::UnknownLoopBound { call_stack }
| RuntimeError::AssertConstantFailed { call_stack }
| RuntimeError::IntegerOutOfBounds { call_stack, .. }
| RuntimeError::UnsupportedIntegerSize { call_stack, .. } => call_stack,
}
}
Expand Down
7 changes: 4 additions & 3 deletions compiler/noirc_evaluator/src/ssa.rs
Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,7 @@ pub(crate) fn optimize_into_acir(
print_brillig_trace: bool,
) -> Result<GeneratedAcir, RuntimeError> {
let abi_distinctness = program.return_distinctness;
let ssa = SsaBuilder::new(program, print_ssa_passes)
let ssa = SsaBuilder::new(program, print_ssa_passes)?
.run_pass(Ssa::defunctionalize, "After Defunctionalization:")
.run_pass(Ssa::inline_functions, "After Inlining:")
// Run mem2reg with the CFG separated into blocks
Expand Down Expand Up @@ -129,8 +129,9 @@ struct SsaBuilder {
}

impl SsaBuilder {
fn new(program: Program, print_ssa_passes: bool) -> SsaBuilder {
SsaBuilder { print_ssa_passes, ssa: ssa_gen::generate_ssa(program) }.print("Initial SSA:")
fn new(program: Program, print_ssa_passes: bool) -> Result<SsaBuilder, RuntimeError> {
let ssa = ssa_gen::generate_ssa(program)?;
Ok(SsaBuilder { print_ssa_passes, ssa }.print("Initial SSA:"))
}

fn finish(self) -> Ssa {
Expand Down
4 changes: 4 additions & 0 deletions compiler/noirc_evaluator/src/ssa/function_builder/mod.rs
Original file line number Diff line number Diff line change
Expand Up @@ -184,6 +184,10 @@ impl FunctionBuilder {
self
}

pub(crate) fn get_call_stack(&self) -> CallStack {
self.call_stack.clone()
}

/// Insert a Load instruction at the end of the current block, loading from the given offset
/// of the given address which should point to a previous Allocate instruction. Note that
/// this is limited to loading a single value. Loading multiple values (such as a tuple)
Expand Down
23 changes: 22 additions & 1 deletion compiler/noirc_evaluator/src/ssa/ir/types.rs
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
use std::rc::Rc;

use acvm::FieldElement;
use iter_extended::vecmap;

/// A numeric type in the Intermediate representation
Expand All @@ -11,7 +12,7 @@ use iter_extended::vecmap;
/// Fields do not have a notion of ordering, so this distinction
/// is reasonable.
#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash, Ord, PartialOrd)]
pub(crate) enum NumericType {
pub enum NumericType {
Signed { bit_size: u32 },
Unsigned { bit_size: u32 },
NativeField,
Expand Down Expand Up @@ -94,6 +95,26 @@ impl Type {
}
}

impl NumericType {
/// Returns true if the given Field value is within the numeric limits
/// for the current NumericType.
pub(crate) fn value_is_within_limits(self, field: FieldElement) -> bool {
match self {
NumericType::Signed { bit_size } => {
let min = -(2i128.pow(bit_size - 1));
let max = 2u128.pow(bit_size - 1) - 1;
// Signed integers are odd since they will overflow the field value
field <= max.into() || field >= min.into()
}
NumericType::Unsigned { bit_size } => {
let max = 2u128.pow(bit_size) - 1;
field <= max.into()
}
NumericType::NativeField => true,
}
}
}

/// Composite Types are essentially flattened struct or tuple types.
/// Array types may have these as elements where each flattened field is
/// included in the array sequentially.
Expand Down
82 changes: 60 additions & 22 deletions compiler/noirc_evaluator/src/ssa/ssa_gen/context.rs
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ use noirc_frontend::monomorphization::ast::{self, LocalId, Parameters};
use noirc_frontend::monomorphization::ast::{FuncId, Program};
use noirc_frontend::{BinaryOpKind, Signedness};

use crate::errors::RuntimeError;
use crate::ssa::function_builder::FunctionBuilder;
use crate::ssa::ir::dfg::DataFlowGraph;
use crate::ssa::ir::function::FunctionId as IrFunctionId;
Expand Down Expand Up @@ -240,6 +241,32 @@ impl<'a> FunctionContext<'a> {
Values::empty()
}

/// Insert a numeric constant into the current function
///
/// Unlike FunctionBuilder::numeric_constant, this version checks the given constant
/// is within the range of the given type. This is needed for user provided values where
/// otherwise values like 2^128 can be assigned to a u8 without error or wrapping.
pub(super) fn checked_numeric_constant(
&mut self,
value: impl Into<FieldElement>,
typ: Type,
) -> Result<ValueId, RuntimeError> {
let value = value.into();

if let Type::Numeric(typ) = typ {
if !typ.value_is_within_limits(value) {
let call_stack = self.builder.get_call_stack();
return Err(RuntimeError::IntegerOutOfBounds { value, typ, call_stack });
}
} else {
panic!("Expected type for numeric constant to be a numeric type, found {typ}");
}

Ok(self.builder.numeric_constant(value, typ))
}



/// Insert a binary instruction at the end of the current block.
/// Converts the form of the binary instruction as necessary
/// (e.g. swapping arguments, inserting a not) to represent it in the IR.
Expand Down Expand Up @@ -500,8 +527,11 @@ impl<'a> FunctionContext<'a> {
/// This is operationally equivalent to extract_current_value_recursive, but splitting these
/// into two separate functions avoids cloning the outermost `Values` returned by the recursive
/// version, as it is only needed for recursion.
pub(super) fn extract_current_value(&mut self, lvalue: &ast::LValue) -> LValue {
match lvalue {
pub(super) fn extract_current_value(
&mut self,
lvalue: &ast::LValue,
) -> Result<LValue, RuntimeError> {
Ok(match lvalue {
ast::LValue::Ident(ident) => {
let (reference, should_auto_deref) = self.ident_lvalue(ident);
if should_auto_deref {
Expand All @@ -511,18 +541,18 @@ impl<'a> FunctionContext<'a> {
}
}
ast::LValue::Index { array, index, location, .. } => {
self.index_lvalue(array, index, location).2
self.index_lvalue(array, index, location)?.2
}
ast::LValue::MemberAccess { object, field_index } => {
let (old_object, object_lvalue) = self.extract_current_value_recursive(object);
let (old_object, object_lvalue) = self.extract_current_value_recursive(object)?;
let object_lvalue = Box::new(object_lvalue);
LValue::MemberAccess { old_object, object_lvalue, index: *field_index }
}
ast::LValue::Dereference { reference, .. } => {
let (reference, _) = self.extract_current_value_recursive(reference);
let (reference, _) = self.extract_current_value_recursive(reference)?;
LValue::Dereference { reference }
}
}
})
}

fn dereference_lvalue(&mut self, values: &Values, element_type: &ast::Type) -> Values {
Expand Down Expand Up @@ -552,16 +582,16 @@ impl<'a> FunctionContext<'a> {
array: &ast::LValue,
index: &ast::Expression,
location: &Location,
) -> (ValueId, ValueId, LValue, Option<ValueId>) {
let (old_array, array_lvalue) = self.extract_current_value_recursive(array);
let index = self.codegen_non_tuple_expression(index);
) -> Result<(ValueId, ValueId, LValue, Option<ValueId>), RuntimeError> {
let (old_array, array_lvalue) = self.extract_current_value_recursive(array)?;
let index = self.codegen_non_tuple_expression(index)?;
let array_lvalue = Box::new(array_lvalue);
let array_values = old_array.clone().into_value_list(self);

let location = *location;
// A slice is represented as a tuple (length, slice contents).
// We need to fetch the second value.
if array_values.len() > 1 {
Ok(if array_values.len() > 1 {
let slice_lvalue = LValue::SliceIndex {
old_slice: old_array,
index,
Expand All @@ -573,37 +603,45 @@ impl<'a> FunctionContext<'a> {
let array_lvalue =
LValue::Index { old_array: array_values[0], index, array_lvalue, location };
(array_values[0], index, array_lvalue, None)
}
})
}

fn extract_current_value_recursive(&mut self, lvalue: &ast::LValue) -> (Values, LValue) {
fn extract_current_value_recursive(
&mut self,
lvalue: &ast::LValue,
) -> Result<(Values, LValue), RuntimeError> {
match lvalue {
ast::LValue::Ident(ident) => {
let (variable, should_auto_deref) = self.ident_lvalue(ident);
if should_auto_deref {
let dereferenced = self.dereference_lvalue(&variable, &ident.typ);
(dereferenced, LValue::Dereference { reference: variable })
Ok((dereferenced, LValue::Dereference { reference: variable }))
} else {
(variable.clone(), LValue::Ident)
Ok((variable.clone(), LValue::Ident))
}
}
ast::LValue::Index { array, index, element_type, location } => {
let (old_array, index, index_lvalue, max_length) =
self.index_lvalue(array, index, location);
let element =
self.codegen_array_index(old_array, index, element_type, *location, max_length);
(element, index_lvalue)
self.index_lvalue(array, index, location)?;
let element = self.codegen_array_index(
old_array,
index,
element_type,
*location,
max_length,
)?;
Ok((element, index_lvalue))
}
ast::LValue::MemberAccess { object, field_index: index } => {
let (old_object, object_lvalue) = self.extract_current_value_recursive(object);
let (old_object, object_lvalue) = self.extract_current_value_recursive(object)?;
let object_lvalue = Box::new(object_lvalue);
let element = Self::get_field_ref(&old_object, *index).clone();
(element, LValue::MemberAccess { old_object, object_lvalue, index: *index })
Ok((element, LValue::MemberAccess { old_object, object_lvalue, index: *index }))
}
ast::LValue::Dereference { reference, element_type } => {
let (reference, _) = self.extract_current_value_recursive(reference);
let (reference, _) = self.extract_current_value_recursive(reference)?;
let dereferenced = self.dereference_lvalue(&reference, element_type);
(dereferenced, LValue::Dereference { reference })
Ok((dereferenced, LValue::Dereference { reference }))
}
}
}
Expand Down
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