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fix(compiler): Provide appropriate error during invalid array access (#…
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…1556)
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@ospencer
ospencer committed Dec 23, 2022
1 parent 8c00750 commit 3d7b9e3
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Showing 10 changed files with 557 additions and 355 deletions.
276 changes: 137 additions & 139 deletions compiler/src/codegen/compcore.re
View file
Original file line number Diff line number Diff line change
Expand Up @@ -75,6 +75,8 @@ let assertion_error_closure_ident =
Ident.create_persistent("GRAIN$EXPORT$AssertionError");
let index_out_of_bounds_ident =
Ident.create_persistent("GRAIN$EXPORT$IndexOutOfBounds");
let index_non_integer_ident =
Ident.create_persistent("GRAIN$EXPORT$IndexNonInteger");
let match_failure_ident =
Ident.create_persistent("GRAIN$EXPORT$MatchFailure");

Expand Down Expand Up @@ -136,6 +138,15 @@ let required_global_imports = [
mimp_setup: MSetupNone,
mimp_used: false,
},
{
mimp_id: index_non_integer_ident,
mimp_mod: exception_mod,
mimp_name: Ident.name(index_non_integer_ident),
mimp_type: MGlobalImport(Types.Unmanaged(WasmI32), true),
mimp_kind: MImportWasm,
mimp_setup: MSetupNone,
mimp_used: false,
},
{
mimp_id: match_failure_ident,
mimp_mod: exception_mod,
Expand Down Expand Up @@ -1009,6 +1020,7 @@ let call_error_handler = (wasm_mod, env, err, args) => {
switch (err) {
| Runtime_errors.MatchFailure => (match_failure_ident, None)
| Runtime_errors.IndexOutOfBounds => (index_out_of_bounds_ident, None)
| Runtime_errors.IndexNonInteger => (index_non_integer_ident, None)
| Runtime_errors.AssertionError => (
assertion_error_closure_ident,
Some(get_wasm_imported_name(exception_mod, assertion_error_ident)),
Expand Down Expand Up @@ -1124,56 +1136,136 @@ let compile_array_op = (wasm_mod, env, arr_imm, op) => {
// incref/decref pair). Since it won't live in a local, it wouldn't be
// cleaned up automatically anyway.
compile_imm(~skip_incref=true, wasm_mod, env, arr_imm);
switch (op) {
| MArrayGet(idx_imm) =>
// ASSUMPTION: idx is a basic (non-heap) int
let idx = compile_imm(wasm_mod, env, idx_imm);
let set_idx = () => set_swap(1, untag_number(wasm_mod, idx));
let get_idx = () => get_swap(1);
let set_arr = () => set_swap(2, get_arr_value());
let get_arr = () => get_swap(2);
/* Check that the index is in bounds */
let resolve_idx = () => {
// PRECONDITION: idx is in swap slot 1
// PRECONDITION: arr is in swap slot 2
Expression.Block.make(
wasm_mod,
gensym_label("MArrayGet"),
gensym_label("resolve_idx"),
[
set_idx(),
set_arr(),
/*
Check index not out of bounds (negative end)
*/
error_if_true(
/* Maximum array length in 32-bit mode is less than 2^30, so any heap-allocated int is out of bounds. */
/* Check that the index is a simple int. */
Expression.If.make(
wasm_mod,
Expression.Unary.make(
wasm_mod,
Op.eq_z_int32,
Expression.Binary.make(
wasm_mod,
Op.and_int32,
get_swap(1),
Expression.Const.make(wasm_mod, const_int32(1)),
),
),
Expression.Block.make(
wasm_mod,
gensym_label("IndexNotSimpleInteger"),
[
set_swap(1, load(~offset=4, wasm_mod, get_swap(1))),
Expression.Drop.make(
wasm_mod,
Expression.If.make(
wasm_mod,
Expression.Binary.make(
wasm_mod,
Op.or_int32,
Expression.Binary.make(
wasm_mod,
Op.or_int32,
Expression.Binary.make(
wasm_mod,
Op.eq_int32,
get_swap(1),
Expression.Const.make(
wasm_mod,
const_int32(
tag_val_of_boxed_number_tag_type(BoxedInt32),
),
),
),
Expression.Binary.make(
wasm_mod,
Op.eq_int32,
get_swap(1),
Expression.Const.make(
wasm_mod,
const_int32(
tag_val_of_boxed_number_tag_type(BoxedInt64),
),
),
),
),
Expression.Binary.make(
wasm_mod,
Op.eq_int32,
get_swap(1),
Expression.Const.make(
wasm_mod,
const_int32(
tag_val_of_boxed_number_tag_type(BoxedBigInt),
),
),
),
),
call_error_handler(wasm_mod, env, IndexOutOfBounds, []),
call_error_handler(wasm_mod, env, IndexNonInteger, []),
),
),
],
),
Expression.Null.make(),
),
set_swap(1, untag_number(wasm_mod, get_swap(1))),
/* Resolve a negative index */
Expression.If.make(
wasm_mod,
env,
Expression.Binary.make(
wasm_mod,
Op.gt_s_int32,
Op.lt_s_int32,
get_swap(1),
Expression.Const.make(wasm_mod, const_int32(0)),
),
set_swap(
1,
Expression.Binary.make(
wasm_mod,
Op.mul_int32,
load(~offset=4, wasm_mod, get_arr()),
Expression.Const.make(wasm_mod, const_int32(-1)),
Op.add_int32,
get_swap(1),
load(~offset=4, wasm_mod, get_swap(2)),
),
get_idx(),
),
IndexOutOfBounds,
[],
Expression.Null.make(),
),
/*
Check index not out of bounds (positive end)
Check index not out of bounds
*/
error_if_true(
wasm_mod,
env,
Expression.Binary.make(
wasm_mod,
Op.le_s_int32,
load(~offset=4, wasm_mod, get_arr()),
get_idx(),
Op.le_u_int32,
load(~offset=4, wasm_mod, get_swap(2)),
get_swap(1),
),
IndexOutOfBounds,
[],
),
],
);
};
switch (op) {
| MArrayLength =>
tag_number(wasm_mod, load(~offset=4, wasm_mod, get_arr_value()))
| MArrayGet(idx_imm) =>
let idx = compile_imm(wasm_mod, env, idx_imm);
Expression.Block.make(
wasm_mod,
gensym_label("MArrayGet"),
[
set_swap(1, idx),
set_swap(2, get_arr_value()),
resolve_idx(),
/*
Load item at array+8+(4*idx) and incRef it
*/
Expand All @@ -1188,108 +1280,44 @@ let compile_array_op = (wasm_mod, env, arr_imm, op) => {
Op.add_int32,
Expression.Binary.make(
wasm_mod,
Op.mul_int32,
/* Resolve a negative index */
Expression.If.make(
wasm_mod,
Expression.Binary.make(
wasm_mod,
Op.lt_s_int32,
get_idx(),
Expression.Const.make(wasm_mod, const_int32(0)),
),
Expression.Binary.make(
wasm_mod,
Op.add_int32,
get_idx(),
load(~offset=4, wasm_mod, get_arr()),
),
get_idx(),
),
Expression.Const.make(wasm_mod, const_int32(4)),
Op.shl_int32,
get_swap(1),
Expression.Const.make(wasm_mod, const_int32(2)),
),
get_arr(),
get_swap(2),
),
),
),
],
);
| MArrayLength =>
tag_number(wasm_mod, load(~offset=4, wasm_mod, get_arr_value()))
| MArraySet(idx_imm, val_imm) =>
// ASSUMPTION: idx is a basic (non-heap) int
let idx = compile_imm(wasm_mod, env, idx_imm);
let val_ = compile_imm(wasm_mod, env, val_imm);
let get_idx = () => get_swap(1);
let set_arr = () => set_swap(2, get_arr_value());
let get_arr = () => get_swap(2);
/* Check that the index is in bounds */
Expression.Block.make(
wasm_mod,
gensym_label("MArrayGet"),
gensym_label("MArraySet"),
[
set_swap(1, untag_number(wasm_mod, idx)),
set_arr(),
error_if_true(
wasm_mod,
env,
set_swap(1, idx),
set_swap(2, get_arr_value()),
resolve_idx(),
set_swap(
2,
Expression.Binary.make(
wasm_mod,
Op.gt_s_int32,
Op.add_int32,
Expression.Binary.make(
wasm_mod,
Op.mul_int32,
load(~offset=4, wasm_mod, get_arr()),
Expression.Const.make(wasm_mod, const_int32(-1)),
Op.shl_int32,
get_swap(1),
Expression.Const.make(wasm_mod, const_int32(2)),
),
get_idx(),
),
IndexOutOfBounds,
[],
),
error_if_true(
wasm_mod,
env,
Expression.Binary.make(
wasm_mod,
Op.le_s_int32,
load(~offset=4, wasm_mod, get_arr()),
get_idx(),
get_swap(2),
),
IndexOutOfBounds,
[],
),
store(
~offset=8,
wasm_mod,
Expression.Binary.make(
wasm_mod,
Op.add_int32,
Expression.Binary.make(
wasm_mod,
Op.mul_int32,
/* Resolve a negative index */
Expression.If.make(
wasm_mod,
Expression.Binary.make(
wasm_mod,
Op.lt_s_int32,
get_idx(),
Expression.Const.make(wasm_mod, const_int32(0)),
),
Expression.Binary.make(
wasm_mod,
Op.add_int32,
get_idx(),
load(~offset=4, wasm_mod, get_arr()),
),
get_idx(),
),
Expression.Const.make(wasm_mod, const_int32(4)),
),
get_arr(),
),
// TODO: decref the old item more efficiently (using a swap slot, most likely)
get_swap(2),
Expression.Tuple_extract.make(
wasm_mod,
Expression.Tuple_make.make(
Expand All @@ -1299,37 +1327,7 @@ let compile_array_op = (wasm_mod, env, arr_imm, op) => {
call_decref(
wasm_mod,
env,
load(
~offset=8,
wasm_mod,
Expression.Binary.make(
wasm_mod,
Op.add_int32,
Expression.Binary.make(
wasm_mod,
Op.mul_int32,
/* Resolve a negative index */
Expression.If.make(
wasm_mod,
Expression.Binary.make(
wasm_mod,
Op.lt_s_int32,
get_idx(),
Expression.Const.make(wasm_mod, const_int32(0)),
),
Expression.Binary.make(
wasm_mod,
Op.add_int32,
get_idx(),
load(~offset=4, wasm_mod, get_arr()),
),
get_idx(),
),
Expression.Const.make(wasm_mod, const_int32(4)),
),
get_arr(),
),
),
load(~offset=8, wasm_mod, get_swap(2)),
),
],
),
Expand Down
1 change: 1 addition & 0 deletions compiler/src/codegen/runtime_errors.re
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,5 +4,6 @@ open Sexplib.Conv;
[@deriving sexp]
type grain_error =
| IndexOutOfBounds
| IndexNonInteger
| MatchFailure
| AssertionError;
1 change: 1 addition & 0 deletions compiler/src/codegen/runtime_errors.rei
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3,5 +3,6 @@
[@deriving sexp]
type grain_error =
| IndexOutOfBounds
| IndexNonInteger
| MatchFailure
| AssertionError;
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