nac3core: add bound check for list slice

nac3core/src/codegen/expr.rs

@@ -238,6 +238,7 @@ impl<'ctx, 'a> CodeGenContext<'ctx, 'a> {
 
     pub fn gen_int_ops(
         &mut self,
+        generator: &mut dyn CodeGenerator,
         op: &Operator,
         lhs: BasicValueEnum<'ctx>,
         rhs: BasicValueEnum<'ctx>,
@@ -273,7 +274,7 @@ impl<'ctx, 'a> CodeGenContext<'ctx, 'a> {
             (Operator::RShift, _) => self.builder.build_right_shift(lhs, rhs, true, "rshift").into(),
             (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(self, lhs, rhs, s).into(),
+            (Operator::Pow, s) => integer_power(generator, self, lhs, rhs, s).into(),
             // special implementation?
             (Operator::MatMult, _) => unreachable!(),
         }
@@ -940,9 +941,9 @@ pub fn gen_binop_expr<'ctx, 'a, G: CodeGenerator>(
     // which would be unchanged until further unification, which we would never do
     // when doing code generation for function instances
     Ok(if ty1 == ty2 && [ctx.primitives.int32, ctx.primitives.int64].contains(&ty1) {
-        ctx.gen_int_ops(op, left, right, true)
+        ctx.gen_int_ops(generator, op, left, right, true)
     } else if ty1 == ty2 && [ctx.primitives.uint32, ctx.primitives.uint64].contains(&ty1) {
-        ctx.gen_int_ops(op, left, right, false)
+        ctx.gen_int_ops(generator, op, left, right, false)
     } else if ty1 == ty2 && ctx.primitives.float == ty1 {
         ctx.gen_float_ops(op, left, right)
     } else if ty1 == ctx.primitives.float && ty2 == ctx.primitives.int32 {
@@ -1415,6 +1416,7 @@ pub fn gen_expr<'ctx, 'a, G: CodeGenerator>(
                     let (start, end, step) =
                         handle_slice_indices(lower, upper, step, ctx, generator, v)?;
                     let length = calculate_len_for_slice_range(
+                        generator,
                         ctx,
                         start,
                         ctx.builder
@@ -1436,8 +1438,8 @@ pub fn gen_expr<'ctx, 'a, G: CodeGenerator>(
                     let res_ind =
                         handle_slice_indices(&None, &None, &None, ctx, generator, res_array_ret)?;
                     list_slice_assignment(
+                        generator,
                         ctx,
-                        generator.get_size_type(ctx.ctx),
                         ty,
                         res_array_ret,
                         res_ind,

nac3core/src/codegen/irrt/mod.rs

@@ -6,7 +6,7 @@ use inkwell::{
     context::Context,
     memory_buffer::MemoryBuffer,
     module::Module,
-    types::{BasicTypeEnum, IntType},
+    types::BasicTypeEnum,
     values::{IntValue, PointerValue},
     AddressSpace, IntPredicate,
 };
@@ -34,6 +34,7 @@ pub fn load_irrt(ctx: &Context) -> Module {
 // repeated squaring method adapted from GNU Scientific Library:
 // https://git.savannah.gnu.org/cgit/gsl.git/tree/sys/pow_int.c
 pub fn integer_power<'ctx, 'a>(
+    generator: &mut dyn CodeGenerator,
     ctx: &mut CodeGenContext<'ctx, 'a>,
     base: IntValue<'ctx>,
     exp: IntValue<'ctx>,
@@ -51,7 +52,21 @@ pub fn integer_power<'ctx, 'a>(
         let fn_type = base_type.fn_type(&[base_type.into(), base_type.into()], false);
         ctx.module.add_function(symbol, fn_type, None)
     });
-    // TODO: throw exception when exp < 0
+    // throw exception when exp < 0
+    let ge_zero = ctx.builder.build_int_compare(
+        IntPredicate::SGE,
+        exp,
+        exp.get_type().const_zero(),
+        "assert_int_pow_ge_0",
+    );
+    ctx.make_assert(
+        generator,
+        ge_zero,
+        "0:ValueError",
+        "integer power must be positive or zero",
+        [None, None, None],
+        ctx.current_loc,
+    );
     ctx.builder
         .build_call(pow_fun, &[base.into(), exp.into()], "call_int_pow")
         .try_as_basic_value()
@@ -60,6 +75,7 @@ pub fn integer_power<'ctx, 'a>(
 }
 
 pub fn calculate_len_for_slice_range<'ctx, 'a>(
+    generator: &mut dyn CodeGenerator,
     ctx: &mut CodeGenContext<'ctx, 'a>,
     start: IntValue<'ctx>,
     end: IntValue<'ctx>,
@@ -72,7 +88,21 @@ pub fn calculate_len_for_slice_range<'ctx, 'a>(
         ctx.module.add_function(SYMBOL, fn_t, None)
     });
 
-    // TODO: assert step != 0, throw exception if not
+    // assert step != 0, throw exception if not
+    let not_zero = ctx.builder.build_int_compare(
+        IntPredicate::NE,
+        step,
+        step.get_type().const_zero(),
+        "range_step_ne",
+    );
+    ctx.make_assert(
+        generator,
+        not_zero,
+        "0:ValueError",
+        "step must not be zero",
+        [None, None, None],
+        ctx.current_loc,
+    );
     ctx.builder
         .build_call(len_func, &[start.into(), end.into(), step.into()], "calc_len")
         .try_as_basic_value()
@@ -129,7 +159,6 @@ pub fn handle_slice_indices<'a, 'ctx, G: CodeGenerator>(
     generator: &mut G,
     list: PointerValue<'ctx>,
 ) -> Result<(IntValue<'ctx>, IntValue<'ctx>, IntValue<'ctx>), String> {
-    // TODO: throw exception when step is 0
     let int32 = ctx.ctx.i32_type();
     let zero = int32.const_zero();
     let one = int32.const_int(1, false);
@@ -156,6 +185,21 @@ pub fn handle_slice_indices<'a, 'ctx, G: CodeGenerator>(
                 .unwrap()
                 .to_basic_value_enum(ctx, generator)?
                 .into_int_value();
+            // assert step != 0, throw exception if not
+            let not_zero = ctx.builder.build_int_compare(
+                IntPredicate::NE,
+                step,
+                step.get_type().const_zero(),
+                "range_step_ne",
+            );
+            ctx.make_assert(
+                generator,
+                not_zero,
+                "0:ValueError",
+                "slice step cannot be zero",
+                [None, None, None],
+                ctx.current_loc,
+            );
             let len_id = ctx.builder.build_int_sub(length, one, "lenmin1");
             let neg = ctx.builder.build_int_compare(IntPredicate::SLT, step, zero, "step_is_neg");
             (
@@ -231,14 +275,15 @@ pub fn handle_slice_index_bound<'a, 'ctx, G: CodeGenerator>(
 /// Order of tuples assign_idx and value_idx is ('start', 'end', 'step').
 /// Negative index should be handled before entering this function
 pub fn list_slice_assignment<'ctx, 'a>(
+    generator: &mut dyn CodeGenerator,
     ctx: &mut CodeGenContext<'ctx, 'a>,
-    size_ty: IntType<'ctx>,
     ty: BasicTypeEnum<'ctx>,
     dest_arr: PointerValue<'ctx>,
     dest_idx: (IntValue<'ctx>, IntValue<'ctx>, IntValue<'ctx>),
     src_arr: PointerValue<'ctx>,
     src_idx: (IntValue<'ctx>, IntValue<'ctx>, IntValue<'ctx>),
 ) {
+    let size_ty = generator.get_size_type(ctx.ctx);
     let int8_ptr = ctx.ctx.i8_type().ptr_type(AddressSpace::Generic);
     let int32 = ctx.ctx.i32_type();
     let (fun_symbol, elem_ptr_type) = ("__nac3_list_slice_assign_var_size", int8_ptr);
@@ -282,8 +327,67 @@ pub fn list_slice_assignment<'ctx, 'a>(
     let src_len = ctx.builder.build_int_truncate_or_bit_cast(src_len, int32, "srclen32");
 
     // index in bound and positive should be done
-    // TODO: assert if dest.step == 1 then len(src) <= len(dest) else len(src) == len(dest), and
+    // assert if dest.step == 1 then len(src) <= len(dest) else len(src) == len(dest), and
     // throw exception if not satisfied
+    let src_end = ctx.builder
+        .build_select(
+            ctx.builder.build_int_compare(
+                inkwell::IntPredicate::SLT,
+                src_idx.2,
+                zero,
+                "is_neg",
+            ),
+            ctx.builder.build_int_sub(src_idx.1, one, "e_min_one"),
+            ctx.builder.build_int_add(src_idx.1, one, "e_add_one"),
+            "final_e",
+        )
+        .into_int_value();
+    let dest_end = ctx.builder
+        .build_select(
+            ctx.builder.build_int_compare(
+                inkwell::IntPredicate::SLT,
+                dest_idx.2,
+                zero,
+                "is_neg",
+            ),
+            ctx.builder.build_int_sub(dest_idx.1, one, "e_min_one"),
+            ctx.builder.build_int_add(dest_idx.1, one, "e_add_one"),
+            "final_e",
+        )
+        .into_int_value();
+    let src_slice_len =
+        calculate_len_for_slice_range(generator, ctx, src_idx.0, src_end, src_idx.2);
+    let dest_slice_len =
+        calculate_len_for_slice_range(generator, ctx, dest_idx.0, dest_end, dest_idx.2);
+    let src_eq_dest = ctx.builder.build_int_compare(
+        IntPredicate::EQ,
+        src_slice_len,
+        dest_slice_len,
+        "slice_src_eq_dest",
+    );
+    let src_slt_dest = ctx.builder.build_int_compare(
+        IntPredicate::SLT,
+        src_slice_len,
+        dest_slice_len,
+        "slice_src_slt_dest",
+    );
+    let dest_step_eq_one = ctx.builder.build_int_compare(
+        IntPredicate::EQ,
+        dest_idx.2,
+        dest_idx.2.get_type().const_int(1, false),
+        "slice_dest_step_eq_one",
+    );
+    let cond_1 = ctx.builder.build_and(dest_step_eq_one, src_slt_dest, "slice_cond_1");
+    let cond = ctx.builder.build_or(src_eq_dest, cond_1, "slice_cond");
+    ctx.make_assert(
+        generator,
+        cond,
+        "0:ValueError",
+        "attempt to assign sequence of size {0} to slice of size {1} with step size {2}",
+        [Some(src_slice_len), Some(dest_slice_len), Some(dest_idx.2)],
+        ctx.current_loc,
+    );
+
     let new_len = {
         let args = vec![
             dest_idx.0.into(),   // dest start idx

nac3core/src/codegen/stmt.rs

@@ -134,8 +134,8 @@ pub fn gen_assign<'ctx, 'a, G: CodeGenerator>(
                     };
                 let src_ind = handle_slice_indices(&None, &None, &None, ctx, generator, value)?;
                 list_slice_assignment(
+                    generator,
                     ctx,
-                    generator.get_size_type(ctx.ctx),
                     ty,
                     ls,
                     (start, end, step),

nac3core/src/toplevel/builtins.rs

@@ -670,8 +670,28 @@ pub fn get_builtins(primitives: &mut (PrimitiveStore, Unifier)) -> BuiltinInfo {
                             step = Some(arg.1.clone().to_basic_value_enum(ctx, generator)?);
                         }
                     }
-                    // TODO: error when step == 0
+                    let step = match step {
-                    let step = step.unwrap_or_else(|| int32.const_int(1, false).into());
+                        Some(step) => {
+                            let step = step.into_int_value();
+                            // assert step != 0, throw exception if not
+                            let not_zero = ctx.builder.build_int_compare(
+                                IntPredicate::NE,
+                                step,
+                                step.get_type().const_zero(),
+                                "range_step_ne",
+                            );
+                            ctx.make_assert(
+                                generator,
+                                not_zero,
+                                "0:ValueError",
+                                "range() step must not be zero",
+                                [None, None, None],
+                                ctx.current_loc,
+                            );
+                            step
+                        }
+                        None => int32.const_int(1, false),
+                    };
                     let stop = stop.unwrap_or_else(|| {
                         let v = start.unwrap();
                         start = None;
@@ -973,7 +993,7 @@ pub fn get_builtins(primitives: &mut (PrimitiveStore, Unifier)) -> BuiltinInfo {
                         Ok(if ctx.unifier.unioned(arg_ty, range_ty) {
                             let arg = arg.into_pointer_value();
                             let (start, end, step) = destructure_range(ctx, arg);
-                            Some(calculate_len_for_slice_range(ctx, start, end, step).into())
+                            Some(calculate_len_for_slice_range(generator, ctx, start, end, step).into())
                         } else {
                             let int32 = ctx.ctx.i32_type();
                             let zero = int32.const_zero();