1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064
// Copyright (C) 2019-2024 Aleo Systems Inc.
// This file is part of the Leo library.
// The Leo library is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// The Leo library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
use crate::{TypeChecker, VariableSymbol};
use leo_ast::*;
use leo_errors::{TypeCheckerError, emitter::Handler};
use leo_span::{Span, Symbol, sym};
use snarkvm::console::network::Network;
use itertools::Itertools;
use std::str::FromStr;
fn return_incorrect_type(t1: Option<Type>, t2: Option<Type>, expected: &Option<Type>) -> Option<Type> {
match (t1, t2) {
(Some(t1), Some(t2)) if t1 == t2 => Some(t1),
(Some(t1), Some(t2)) => {
if let Some(expected) = expected {
if &t1 != expected { Some(t1) } else { Some(t2) }
} else {
Some(t1)
}
}
(None, Some(_)) | (Some(_), None) | (None, None) => None,
}
}
impl<'a, N: Network> ExpressionVisitor<'a> for TypeChecker<'a, N> {
type AdditionalInput = Option<Type>;
type Output = Option<Type>;
fn visit_expression(&mut self, input: &'a Expression, additional: &Self::AdditionalInput) -> Self::Output {
let output = match input {
Expression::Access(access) => self.visit_access(access, additional),
Expression::Array(array) => self.visit_array(array, additional),
Expression::Binary(binary) => self.visit_binary(binary, additional),
Expression::Call(call) => self.visit_call(call, additional),
Expression::Cast(cast) => self.visit_cast(cast, additional),
Expression::Struct(struct_) => self.visit_struct_init(struct_, additional),
Expression::Err(err) => self.visit_err(err, additional),
Expression::Identifier(identifier) => self.visit_identifier(identifier, additional),
Expression::Literal(literal) => self.visit_literal(literal, additional),
Expression::Locator(locator) => self.visit_locator(locator, additional),
Expression::Ternary(ternary) => self.visit_ternary(ternary, additional),
Expression::Tuple(tuple) => self.visit_tuple(tuple, additional),
Expression::Unary(unary) => self.visit_unary(unary, additional),
Expression::Unit(unit) => self.visit_unit(unit, additional),
};
// If the output type is known, add the expression and its associated type to the symbol table.
if let Some(type_) = &output {
self.type_table.insert(input.id(), type_.clone());
}
// Return the output type.
output
}
fn visit_access(&mut self, input: &'a AccessExpression, expected: &Self::AdditionalInput) -> Self::Output {
match input {
AccessExpression::Array(access) => {
// Check that the expression is an array.
let array_type = self.visit_expression(&access.array, &None);
self.assert_array_type(&array_type, access.array.span());
// Check that the index is an integer type.
let index_type = self.visit_expression(&access.index, &None);
self.assert_int_type(&index_type, access.index.span());
// Get the element type of the array.
let element_type = match array_type {
Some(Type::Array(array_type)) => Some(array_type.element_type().clone()),
_ => None,
};
// If the expected type is known, then check that the element type is the same as the expected type.
if let Some(expected) = expected {
self.assert_type(&element_type, expected, input.span());
}
// Return the element type of the array.
return element_type;
}
AccessExpression::AssociatedFunction(access) => {
// Check core struct name and function.
if let Some(core_instruction) = self.get_core_function_call(&access.variant, &access.name) {
// Check that operation is not restricted to finalize blocks.
if self.scope_state.variant != Some(Variant::AsyncFunction)
&& core_instruction.is_finalize_command()
{
self.emit_err(TypeCheckerError::operation_must_be_in_finalize_block(input.span()));
}
// Get the types of the arguments.
let argument_types = access
.arguments
.iter()
.map(|arg| (self.visit_expression(arg, &None), arg.span()))
.collect::<Vec<_>>();
// Check that the types of the arguments are valid.
let return_type =
self.check_core_function_call(core_instruction.clone(), &argument_types, input.span());
// Check return type if the expected type is known.
if let Some(expected) = expected {
self.assert_type(&return_type, expected, input.span());
}
// Await futures here so that can use the argument variable names to lookup.
if core_instruction == CoreFunction::FutureAwait {
if access.arguments.len() != 1 {
self.emit_err(TypeCheckerError::can_only_await_one_future_at_a_time(access.span));
return Some(Type::Unit);
}
self.assert_future_await(&access.arguments.first(), input.span());
}
return return_type;
} else {
self.emit_err(TypeCheckerError::invalid_core_function_call(access, access.span()));
}
}
AccessExpression::Tuple(access) => {
if let Some(type_) = self.visit_expression(&access.tuple, &None) {
match type_ {
Type::Tuple(tuple) => {
// Check out of range access.
let index = access.index.value();
if index > tuple.length() - 1 {
self.emit_err(TypeCheckerError::tuple_out_of_range(
index,
tuple.length(),
access.span(),
));
} else {
// Lookup type of tuple index.
let actual = tuple.elements().get(index).expect("failed to get tuple index").clone();
// Emit error for mismatched types.
if let Some(expected) = expected {
self.check_eq_types(&Some(actual.clone()), &Some(expected.clone()), access.span());
}
// Return type of tuple index.
return Some(actual);
}
}
Type::Future(_) => {
// Get the fully inferred type.
if let Some(Type::Future(inferred_f)) = self.type_table.get(&access.tuple.id()) {
// Make sure in range.
if access.index.value() >= inferred_f.inputs().len() {
self.emit_err(TypeCheckerError::invalid_future_access(
access.index.value(),
inferred_f.inputs().len(),
access.span(),
));
} else {
// Return the type of the input parameter.
return Some(self.assert_and_return_type(
inferred_f.inputs().get(access.index.value()).unwrap().clone(),
expected,
access.span(),
));
}
}
}
type_ => {
self.emit_err(TypeCheckerError::type_should_be(type_, "tuple", access.span()));
}
}
self.emit_err(TypeCheckerError::invalid_core_function_call(access, access.span()));
}
}
AccessExpression::Member(access) => {
match *access.inner {
// If the access expression is of the form `self.<name>`, then check the <name> is valid.
Expression::Identifier(identifier) if identifier.name == sym::SelfLower => match access.name.name {
sym::caller => {
// Check that the operation is not invoked in a `finalize` block.
self.check_access_allowed("self.caller", false, access.name.span());
return Some(Type::Address);
}
sym::signer => {
// Check that operation is not invoked in a `finalize` block.
self.check_access_allowed("self.signer", false, access.name.span());
return Some(Type::Address);
}
_ => {
self.emit_err(TypeCheckerError::invalid_self_access(access.name.span()));
}
},
// If the access expression is of the form `block.<name>`, then check the <name> is valid.
Expression::Identifier(identifier) if identifier.name == sym::block => match access.name.name {
sym::height => {
// Check that the operation is invoked in a `finalize` block.
self.check_access_allowed("block.height", true, access.name.span());
return Some(Type::Integer(IntegerType::U32));
}
_ => {
self.emit_err(TypeCheckerError::invalid_block_access(access.name.span()));
}
},
// If the access expression is of the form `network.<name>`, then check that the <name> is valid.
Expression::Identifier(identifier) if identifier.name == sym::network => match access.name.name {
sym::id => {
// Check that the operation is not invoked outside a `finalize` block.
self.check_access_allowed("network.id", true, access.name.span());
return Some(Type::Integer(IntegerType::U16));
}
_ => {
self.emit_err(TypeCheckerError::invalid_block_access(access.name.span()));
}
},
_ => {
// Check that the type of `inner` in `inner.name` is a struct.
match self.visit_expression(&access.inner, &None) {
Some(Type::Composite(struct_)) => {
// Retrieve the struct definition associated with `identifier`.
let struct_ = self.lookup_struct(struct_.program, struct_.id.name);
if let Some(struct_) = struct_ {
// Check that `access.name` is a member of the struct.
match struct_.members.iter().find(|member| member.name() == access.name.name) {
// Case where `access.name` is a member of the struct.
Some(Member { type_, .. }) => {
// Check that the type of `access.name` is the same as `expected`.
return Some(self.assert_and_return_type(
type_.clone(),
expected,
access.span(),
));
}
// Case where `access.name` is not a member of the struct.
None => {
self.emit_err(TypeCheckerError::invalid_struct_variable(
access.name,
&struct_,
access.name.span(),
));
}
}
} else {
self.emit_err(TypeCheckerError::undefined_type(&access.inner, access.inner.span()));
}
}
Some(type_) => {
self.emit_err(TypeCheckerError::type_should_be(type_, "struct", access.inner.span()));
}
None => {
self.emit_err(TypeCheckerError::could_not_determine_type(
&access.inner,
access.inner.span(),
));
}
}
}
}
}
AccessExpression::AssociatedConstant(access) => {
// Check associated constant type and constant name
if let Some(core_constant) = self.get_core_constant(&access.ty, &access.name) {
// Check return type if the expected type is known.
let return_type = Some(core_constant.to_type());
if let Some(expected) = expected {
self.assert_type(&return_type, expected, input.span());
}
return return_type;
} else {
self.emit_err(TypeCheckerError::invalid_associated_constant(access, access.span))
}
}
}
None
}
fn visit_array(&mut self, input: &'a ArrayExpression, additional: &Self::AdditionalInput) -> Self::Output {
// Get the types of each element expression.
let element_types =
input.elements.iter().map(|element| self.visit_expression(element, &None)).collect::<Vec<_>>();
// Construct the array type.
let return_type = match element_types.len() {
// The array cannot be empty.
0 => {
self.emit_err(TypeCheckerError::array_empty(input.span()));
None
}
num_elements => {
if num_elements <= N::MAX_ARRAY_ELEMENTS {
// Check that the element types match.
let mut element_types = element_types.into_iter();
// Note that this unwrap is safe because we already checked that the array is not empty.
element_types.next().unwrap().map(|first_type| {
// Check that all elements have the same type.
for (element_type, element) in element_types.zip_eq(input.elements.iter().skip(1)) {
self.assert_type(&element_type, &first_type, element.span());
}
// Return the array type.
Type::Array(ArrayType::new(first_type, NonNegativeNumber::from(input.elements.len())))
})
} else {
// The array cannot have more than `MAX_ARRAY_ELEMENTS` elements.
self.emit_err(TypeCheckerError::array_too_large(num_elements, N::MAX_ARRAY_ELEMENTS, input.span()));
None
}
}
};
// If the expected type is known, then check that the array type is the same as the expected type.
if let Some(expected) = additional {
self.assert_type(&return_type, expected, input.span());
}
// Return the array type.
return_type
}
fn visit_binary(&mut self, input: &'a BinaryExpression, destination: &Self::AdditionalInput) -> Self::Output {
match input.op {
BinaryOperation::And | BinaryOperation::Or | BinaryOperation::Nand | BinaryOperation::Nor => {
// Only boolean types.
self.assert_bool_type(destination, input.span());
let t1 = self.visit_expression(&input.left, destination);
let t2 = self.visit_expression(&input.right, destination);
// Check that both operands have the same type.
self.check_eq_types(&t1, &t2, input.span());
return_incorrect_type(t1, t2, destination)
}
BinaryOperation::BitwiseAnd | BinaryOperation::BitwiseOr | BinaryOperation::Xor => {
// Only boolean or integer types.
self.assert_bool_int_type(destination, input.span());
let t1 = self.visit_expression(&input.left, destination);
let t2 = self.visit_expression(&input.right, destination);
// Check that both operands have the same type.
self.check_eq_types(&t1, &t2, input.span());
return_incorrect_type(t1, t2, destination)
}
BinaryOperation::Add => {
// Only field, group, scalar, or integer types.
self.assert_field_group_scalar_int_type(destination, input.span());
let t1 = self.visit_expression(&input.left, destination);
let t2 = self.visit_expression(&input.right, destination);
// Check that both operands have the same type.
self.check_eq_types(&t1, &t2, input.span());
return_incorrect_type(t1, t2, destination)
}
BinaryOperation::Sub => {
// Only field, group, or integer types.
self.assert_field_group_int_type(destination, input.span());
let t1 = self.visit_expression(&input.left, destination);
let t2 = self.visit_expression(&input.right, destination);
// Check that both operands have the same type.
self.check_eq_types(&t1, &t2, input.span());
return_incorrect_type(t1, t2, destination)
}
BinaryOperation::Mul => {
// Operation returns field, group or integer types.
self.assert_field_group_int_type(destination, input.span());
let t1 = self.visit_expression(&input.left, &None);
let t2 = self.visit_expression(&input.right, &None);
// Allow group * scalar multiplication.
match (t1, input.left.span(), t2, input.right.span()) {
(Some(Type::Group), _, other, other_span) | (other, other_span, Some(Type::Group), _) => {
// Other type must be scalar.
self.assert_scalar_type(&other, other_span);
// Operation returns group.
self.assert_group_type(destination, input.span());
Some(Type::Group)
}
(Some(Type::Field), _, other, other_span) | (other, other_span, Some(Type::Field), _) => {
// Other type must be field.
self.assert_field_type(&other, other_span);
// Operation returns field.
self.assert_field_type(destination, input.span());
Some(Type::Field)
}
(Some(Type::Integer(integer_type)), _, other, other_span)
| (other, other_span, Some(Type::Integer(integer_type)), _) => {
// Other type must be the same integer type.
self.assert_type(&other, &Type::Integer(integer_type), other_span);
// Operation returns the same integer type.
self.assert_type(destination, &Type::Integer(integer_type), input.span());
Some(Type::Integer(integer_type))
}
(left_type, left_span, right_type, right_span) => {
let check_type = |type_: Option<Type>, expression: &Expression, span: Span| match type_ {
None => {
self.emit_err(TypeCheckerError::could_not_determine_type(expression, span));
}
Some(type_) => {
self.emit_err(TypeCheckerError::type_should_be(
type_,
"field, group, integer, or scalar",
span,
));
}
};
check_type(left_type, &input.left, left_span);
check_type(right_type, &input.right, right_span);
destination.clone()
}
}
}
BinaryOperation::Div => {
// Only field or integer types.
self.assert_field_int_type(destination, input.span());
let t1 = self.visit_expression(&input.left, destination);
let t2 = self.visit_expression(&input.right, destination);
// Check that both operands have the same type.
self.check_eq_types(&t1, &t2, input.span());
return_incorrect_type(t1, t2, destination)
}
BinaryOperation::Rem | BinaryOperation::RemWrapped => {
// Only integer types.
self.assert_int_type(destination, input.span());
let t1 = self.visit_expression(&input.left, destination);
let t2 = self.visit_expression(&input.right, destination);
// Check that both operands have the same type.
self.check_eq_types(&t1, &t2, input.span());
return_incorrect_type(t1, t2, destination)
}
BinaryOperation::Mod => {
// Only unsigned integer types.
self.assert_unsigned_int_type(destination, input.span());
let t1 = self.visit_expression(&input.left, destination);
let t2 = self.visit_expression(&input.right, destination);
// Check that both operands have the same type.
self.check_eq_types(&t1, &t2, input.span());
return_incorrect_type(t1, t2, destination)
}
BinaryOperation::Pow => {
// Operation returns field or integer types.
self.assert_field_int_type(destination, input.span());
let t1 = self.visit_expression(&input.left, &None);
let t2 = self.visit_expression(&input.right, &None);
// Allow field ^ field.
match (t1, t2) {
(Some(Type::Field), right) => {
// Right must be field.
self.assert_field_type(&right, input.right.span());
// Operation returns field.
self.assert_field_type(destination, input.span());
Some(Type::Field)
}
(left, Some(Type::Field)) => {
// Left must be field.
self.assert_field_type(&left, input.left.span());
// Operation returns field.
self.assert_field_type(destination, input.span());
Some(Type::Field)
}
(Some(left), right) => {
// Left type is checked to be an integer by above.
// Right type must be magnitude (u8, u16, u32).
self.assert_magnitude_type(&right, input.right.span());
// Operation returns left type.
self.assert_type(destination, &left, input.span());
Some(left)
}
(None, right) => {
// Lhs type is checked to be an integer by above.
// Rhs type must be magnitude (u8, u16, u32).
self.assert_magnitude_type(&right, input.right.span());
destination.clone()
}
}
}
BinaryOperation::Eq | BinaryOperation::Neq => {
// Assert first and second address, boolean, field, group, scalar, or integer types.
let t1 = self.visit_expression(&input.left, &None);
let t2 = self.visit_expression(&input.right, &None);
// Check that the types of the operands are equal.
self.check_eq_types(&t1, &t2, input.span());
// Operation returns a boolean.
self.assert_bool_type(destination, input.span());
Some(Type::Boolean)
}
BinaryOperation::Lt | BinaryOperation::Gt | BinaryOperation::Lte | BinaryOperation::Gte => {
// Assert left and right are equal field, scalar, or integer types.
let t1 = self.visit_expression(&input.left, &None);
let t2 = self.visit_expression(&input.right, &None);
match (&t1, &t2) {
(Some(Type::Address), _) | (_, Some(Type::Address)) => {
// Emit an error for address comparison.
self.emit_err(TypeCheckerError::compare_address(input.op, input.span()));
}
(t1, t2) => {
self.assert_field_scalar_int_type(t1, input.left.span());
self.assert_field_scalar_int_type(t2, input.right.span());
}
}
// Check that the types of the operands are equal.
self.check_eq_types(&t1, &t2, input.span());
// Operation returns a boolean.
self.assert_bool_type(destination, input.span());
Some(Type::Boolean)
}
BinaryOperation::AddWrapped
| BinaryOperation::SubWrapped
| BinaryOperation::DivWrapped
| BinaryOperation::MulWrapped => {
// Only integer types.
self.assert_int_type(destination, input.span);
let t1 = self.visit_expression(&input.left, destination);
let t2 = self.visit_expression(&input.right, destination);
// Check that both operands have the same type.
self.check_eq_types(&t1, &t2, input.span());
return_incorrect_type(t1, t2, destination)
}
BinaryOperation::Shl
| BinaryOperation::ShlWrapped
| BinaryOperation::Shr
| BinaryOperation::ShrWrapped
| BinaryOperation::PowWrapped => {
let t1 = self.visit_expression(&input.left, destination);
let t2 = self.visit_expression(&input.right, &None);
// Assert left and destination are equal integer types.
self.assert_int_type(&t1, input.left.span());
self.assert_int_type(destination, input.span);
// Assert right type is a magnitude (u8, u16, u32).
self.assert_magnitude_type(&t2, input.right.span());
t1
}
}
}
fn visit_call(&mut self, input: &'a CallExpression, expected: &Self::AdditionalInput) -> Self::Output {
match &*input.function {
// Note that the parser guarantees that `input.function` is always an identifier.
Expression::Identifier(ident) => {
// Note: The function symbol lookup is performed outside of the `if let Some(func) ...` block to avoid a RefCell lifetime bug in Rust.
// Do not move it into the `if let Some(func) ...` block or it will keep `self.symbol_table_creation` alive for the entire block and will be very memory inefficient!
let func =
self.symbol_table.borrow().lookup_fn_symbol(Location::new(input.program, ident.name)).cloned();
if let Some(func) = func {
// Check that the call is valid.
// Note that this unwrap is safe since we always set the variant before traversing the body of the function.
match self.scope_state.variant.unwrap() {
Variant::AsyncFunction | Variant::Function if !matches!(func.variant, Variant::Inline) => {
self.emit_err(TypeCheckerError::can_only_call_inline_function(input.span))
}
Variant::Transition | Variant::AsyncTransition
if matches!(func.variant, Variant::Transition)
&& input.program.unwrap() == self.scope_state.program_name.unwrap() =>
{
self.emit_err(TypeCheckerError::cannot_invoke_call_to_local_transition_function(input.span))
}
_ => {}
}
// Check that the call is not to an external `inline` function.
if func.variant == Variant::Inline
&& input.program.unwrap() != self.scope_state.program_name.unwrap()
{
self.emit_err(TypeCheckerError::cannot_call_external_inline_function(input.span));
}
// Async functions return a single future.
let mut ret = if func.variant == Variant::AsyncFunction {
// Type check after resolving the input types.
if let Some(Type::Future(_)) = expected {
Type::Future(FutureType::new(
Vec::new(),
Some(Location::new(input.program, ident.name)),
false,
))
} else {
self.emit_err(TypeCheckerError::return_type_of_finalize_function_is_future(input.span));
Type::Unit
}
} else if func.variant == Variant::AsyncTransition {
// Fully infer future type.
let future_type = match self
.async_function_input_types
.get(&Location::new(input.program, Symbol::intern(&format!("finalize/{}", ident.name))))
{
Some(inputs) => Type::Future(FutureType::new(
inputs.clone(),
Some(Location::new(input.program, ident.name)),
true,
)),
None => {
self.emit_err(TypeCheckerError::async_function_not_found(ident.name, input.span));
return Some(Type::Future(FutureType::new(
Vec::new(),
Some(Location::new(input.program, ident.name)),
false,
)));
}
};
let fully_inferred_type = match func.output_type {
Type::Tuple(tup) => Type::Tuple(TupleType::new(
tup.elements()
.iter()
.map(|t| if matches!(t, Type::Future(_)) { future_type.clone() } else { t.clone() })
.collect::<Vec<Type>>(),
)),
Type::Future(_) => future_type,
_ => panic!("Invalid output type for async transition."),
};
self.assert_and_return_type(fully_inferred_type, expected, input.span())
} else {
self.assert_and_return_type(func.output_type, expected, input.span())
};
// Check number of function arguments.
if func.input.len() != input.arguments.len() {
self.emit_err(TypeCheckerError::incorrect_num_args_to_call(
func.input.len(),
input.arguments.len(),
input.span(),
));
}
// Check function argument types.
self.scope_state.is_call = true;
let (mut input_futures, mut inferred_finalize_inputs) = (Vec::new(), Vec::new());
for (expected, argument) in func.input.iter().zip(input.arguments.iter()) {
// Get the type of the expression. If the type is not known, do not attempt to attempt any futher inference.
let ty = self.visit_expression(argument, &Some(expected.type_().clone()))?;
// Extract information about futures that are being consumed.
if func.variant == Variant::AsyncFunction && matches!(expected.type_(), Type::Future(_)) {
match argument {
Expression::Identifier(_)
| Expression::Call(_)
| Expression::Access(AccessExpression::Tuple(_)) => {
match self.scope_state.call_location.clone() {
Some(location) => {
// Get the external program and function name.
input_futures.push(location);
// Get the full inferred type.
inferred_finalize_inputs.push(ty);
}
None => {
self.emit_err(TypeCheckerError::unknown_future_consumed(
argument,
argument.span(),
));
}
}
}
_ => {
self.emit_err(TypeCheckerError::unknown_future_consumed(
"unknown",
argument.span(),
));
}
}
} else {
inferred_finalize_inputs.push(ty);
}
}
self.scope_state.is_call = false;
// Add the call to the call graph.
let caller_name = match self.scope_state.function {
None => unreachable!("`self.function` is set every time a function is visited."),
Some(func) => func,
};
// Don't add external functions to call graph. Since imports are acyclic, these can never produce a cycle.
if input.program.unwrap() == self.scope_state.program_name.unwrap() {
self.call_graph.add_edge(caller_name, ident.name);
}
// Propagate futures from async functions and transitions.
if func.variant.is_async_function() {
// Cannot have async calls in a conditional block.
if self.scope_state.is_conditional {
self.emit_err(TypeCheckerError::async_call_in_conditional(input.span));
}
// Can only call async functions and external async transitions from an async transition body.
if self.scope_state.variant != Some(Variant::AsyncTransition) {
self.emit_err(TypeCheckerError::async_call_can_only_be_done_from_async_transition(
input.span,
));
}
if func.variant.is_transition() {
// Cannot call an external async transition after having called the async function.
if self.scope_state.has_called_finalize {
self.emit_err(TypeCheckerError::external_transition_call_must_be_before_finalize(
input.span,
));
}
} else if func.variant.is_function() {
// Can only call an async function once in a transition function body.
if self.scope_state.has_called_finalize {
self.emit_err(TypeCheckerError::must_call_async_function_once(input.span));
}
// Check that all futures consumed.
if !self.scope_state.futures.is_empty() {
self.emit_err(TypeCheckerError::not_all_futures_consumed(
self.scope_state.futures.iter().map(|(f, _)| f.to_string()).join(", "),
input.span,
));
}
// Add future locations to symbol table. Unwrap safe since insert function into symbol table during previous pass.
let mut st = self.symbol_table.borrow_mut();
// Insert futures into symbol table.
st.insert_futures(input.program.unwrap(), ident.name, input_futures).unwrap();
// Link async transition to the async function that finalizes it.
st.attach_finalize(
self.scope_state.location(),
Location::new(self.scope_state.program_name, ident.name),
)
.unwrap();
drop(st);
// Create expectation for finalize inputs that will be checked when checking corresponding finalize function signature.
self.async_function_input_types.insert(
Location::new(self.scope_state.program_name, ident.name),
inferred_finalize_inputs.clone(),
);
// Set scope state flag.
self.scope_state.has_called_finalize = true;
// Update ret to reflect fully inferred future type.
ret = Type::Future(FutureType::new(
inferred_finalize_inputs,
Some(Location::new(input.program, ident.name)),
true,
));
// Type check in case the expected type is known.
self.assert_and_return_type(ret.clone(), expected, input.span());
}
}
// Set call location so that definition statement knows where future comes from.
self.scope_state.call_location = Some(Location::new(input.program, ident.name));
Some(ret)
} else {
self.emit_err(TypeCheckerError::unknown_sym("function", ident.name, ident.span()));
None
}
}
_ => unreachable!("Parsing guarantees that a function name is always an identifier."),
}
}
fn visit_cast(&mut self, input: &'a CastExpression, expected: &Self::AdditionalInput) -> Self::Output {
// Check that the target type of the cast expression is a castable type.
self.assert_castable_type(&Some(input.type_.clone()), input.span());
// Check that the expression type is a primitive type.
let expression_type = self.visit_expression(&input.expression, &None);
self.assert_castable_type(&expression_type, input.expression.span());
// Check that the expected type matches the target type.
Some(self.assert_and_return_type(input.type_.clone(), expected, input.span()))
}
fn visit_struct_init(&mut self, input: &'a StructExpression, additional: &Self::AdditionalInput) -> Self::Output {
let struct_ = self.lookup_struct(self.scope_state.program_name, input.name.name).clone();
if let Some(struct_) = struct_ {
// Check struct type name.
let ret = self.check_expected_struct(&struct_, additional, input.name.span());
// Check number of struct members.
if struct_.members.len() != input.members.len() {
self.emit_err(TypeCheckerError::incorrect_num_struct_members(
struct_.members.len(),
input.members.len(),
input.span(),
));
}
// Check struct member types.
struct_.members.iter().for_each(|Member { identifier, type_, .. }| {
// Lookup struct variable name.
if let Some(actual) = input.members.iter().find(|member| member.identifier.name == identifier.name) {
match &actual.expression {
// If `expression` is None, then the member uses the identifier shorthand, e.g. `Foo { a }`
None => self.visit_identifier(&actual.identifier, &Some(type_.clone())),
// Otherwise, visit the associated expression.
Some(expr) => self.visit_expression(expr, &Some(type_.clone())),
};
} else {
self.emit_err(TypeCheckerError::missing_struct_member(
struct_.identifier,
identifier,
input.span(),
));
};
});
Some(ret)
} else {
self.emit_err(TypeCheckerError::unknown_sym("struct", input.name.name, input.name.span()));
None
}
}
// We do not want to panic on `ErrExpression`s in order to propagate as many errors as possible.
fn visit_err(&mut self, _input: &'a ErrExpression, _additional: &Self::AdditionalInput) -> Self::Output {
Default::default()
}
fn visit_identifier(&mut self, input: &'a Identifier, expected: &Self::AdditionalInput) -> Self::Output {
let var = self.symbol_table.borrow().lookup_variable(Location::new(None, input.name)).cloned();
if let Some(var) = &var {
if matches!(var.type_, Type::Future(_)) && matches!(expected, Some(Type::Future(_))) {
if self.scope_state.variant == Some(Variant::AsyncTransition) && self.scope_state.is_call {
// Consume future.
match self.scope_state.futures.remove(&input.name) {
Some(future) => {
self.scope_state.call_location = Some(future.clone());
return Some(var.type_.clone());
}
None => {
self.emit_err(TypeCheckerError::unknown_future_consumed(input.name, input.span));
}
}
} else {
// Case where accessing input argument of future. Ex `f.1`.
return Some(var.type_.clone());
}
}
Some(self.assert_and_return_type(var.type_.clone(), expected, input.span()))
} else {
self.emit_err(TypeCheckerError::unknown_sym("variable", input.name, input.span()));
None
}
}
fn visit_literal(&mut self, input: &'a Literal, expected: &Self::AdditionalInput) -> Self::Output {
fn parse_integer_literal<I: FromStr>(handler: &Handler, raw_string: &str, span: Span, type_string: &str) {
let string = raw_string.replace('_', "");
if string.parse::<I>().is_err() {
handler.emit_err(TypeCheckerError::invalid_int_value(string, type_string, span));
}
}
Some(match input {
Literal::Address(_, _, _) => self.assert_and_return_type(Type::Address, expected, input.span()),
Literal::Boolean(_, _, _) => self.assert_and_return_type(Type::Boolean, expected, input.span()),
Literal::Field(_, _, _) => self.assert_and_return_type(Type::Field, expected, input.span()),
Literal::Integer(integer_type, string, _, _) => match integer_type {
IntegerType::U8 => {
parse_integer_literal::<u8>(self.handler, string, input.span(), "u8");
self.assert_and_return_type(Type::Integer(IntegerType::U8), expected, input.span())
}
IntegerType::U16 => {
parse_integer_literal::<u16>(self.handler, string, input.span(), "u16");
self.assert_and_return_type(Type::Integer(IntegerType::U16), expected, input.span())
}
IntegerType::U32 => {
parse_integer_literal::<u32>(self.handler, string, input.span(), "u32");
self.assert_and_return_type(Type::Integer(IntegerType::U32), expected, input.span())
}
IntegerType::U64 => {
parse_integer_literal::<u64>(self.handler, string, input.span(), "u64");
self.assert_and_return_type(Type::Integer(IntegerType::U64), expected, input.span())
}
IntegerType::U128 => {
parse_integer_literal::<u128>(self.handler, string, input.span(), "u128");
self.assert_and_return_type(Type::Integer(IntegerType::U128), expected, input.span())
}
IntegerType::I8 => {
parse_integer_literal::<i8>(self.handler, string, input.span(), "i8");
self.assert_and_return_type(Type::Integer(IntegerType::I8), expected, input.span())
}
IntegerType::I16 => {
parse_integer_literal::<i16>(self.handler, string, input.span(), "i16");
self.assert_and_return_type(Type::Integer(IntegerType::I16), expected, input.span())
}
IntegerType::I32 => {
parse_integer_literal::<i32>(self.handler, string, input.span(), "i32");
self.assert_and_return_type(Type::Integer(IntegerType::I32), expected, input.span())
}
IntegerType::I64 => {
parse_integer_literal::<i64>(self.handler, string, input.span(), "i64");
self.assert_and_return_type(Type::Integer(IntegerType::I64), expected, input.span())
}
IntegerType::I128 => {
parse_integer_literal::<i128>(self.handler, string, input.span(), "i128");
self.assert_and_return_type(Type::Integer(IntegerType::I128), expected, input.span())
}
},
Literal::Group(_) => self.assert_and_return_type(Type::Group, expected, input.span()),
Literal::Scalar(_, _, _) => self.assert_and_return_type(Type::Scalar, expected, input.span()),
Literal::String(_, _, _) => {
self.emit_err(TypeCheckerError::strings_are_not_supported(input.span()));
self.assert_and_return_type(Type::String, expected, input.span())
}
})
}
fn visit_locator(&mut self, input: &'a LocatorExpression, expected: &Self::AdditionalInput) -> Self::Output {
// Check that the locator points to a valid resource in the ST.
let loc_: VariableSymbol;
if let Some(var) =
self.symbol_table.borrow().lookup_variable(Location::new(Some(input.program.name.name), input.name))
{
loc_ = var.clone();
} else {
self.emit_err(TypeCheckerError::unknown_sym("variable", input.name, input.span()));
return None;
}
Some(self.assert_and_return_type(loc_.type_.clone(), expected, input.span()))
}
fn visit_ternary(&mut self, input: &'a TernaryExpression, expected: &Self::AdditionalInput) -> Self::Output {
self.visit_expression(&input.condition, &Some(Type::Boolean));
let t1 = self.visit_expression(&input.if_true, expected);
let t2 = self.visit_expression(&input.if_false, expected);
return_incorrect_type(t1, t2, expected)
}
fn visit_tuple(&mut self, input: &'a TupleExpression, expected: &Self::AdditionalInput) -> Self::Output {
match input.elements.len() {
0 | 1 => unreachable!("Parsing guarantees that tuple expressions have at least two elements."),
_ => {
// Check the expected tuple types if they are known.
if let Some(Type::Tuple(expected_types)) = expected {
// Check actual length is equal to expected length.
if expected_types.length() != input.elements.len() {
self.emit_err(TypeCheckerError::incorrect_tuple_length(
expected_types.length(),
input.elements.len(),
input.span(),
));
}
expected_types.elements().iter().zip(input.elements.iter()).for_each(|(expected, expr)| {
// Check that the component expression is not a tuple.
if matches!(expr, Expression::Tuple(_)) {
self.emit_err(TypeCheckerError::nested_tuple_expression(expr.span()))
}
self.visit_expression(expr, &Some(expected.clone()));
});
Some(Type::Tuple(expected_types.clone()))
} else {
// Tuples must be explicitly typed.
self.emit_err(TypeCheckerError::invalid_tuple(input.span()));
None
}
}
}
}
fn visit_unary(&mut self, input: &'a UnaryExpression, destination: &Self::AdditionalInput) -> Self::Output {
match input.op {
UnaryOperation::Abs => {
// Only signed integer types.
self.assert_signed_int_type(destination, input.span());
self.visit_expression(&input.receiver, destination)
}
UnaryOperation::AbsWrapped => {
// Only signed integer types.
self.assert_signed_int_type(destination, input.span());
self.visit_expression(&input.receiver, destination)
}
UnaryOperation::Double => {
// Only field or group types.
self.assert_field_group_type(destination, input.span());
self.visit_expression(&input.receiver, destination)
}
UnaryOperation::Inverse => {
// Only field types.
self.assert_field_type(destination, input.span());
self.visit_expression(&input.receiver, destination)
}
UnaryOperation::Negate => {
let type_ = self.visit_expression(&input.receiver, destination);
// Only field, group, or signed integer types.
self.assert_field_group_signed_int_type(&type_, input.receiver.span());
type_
}
UnaryOperation::Not => {
// Only boolean or integer types.
self.assert_bool_int_type(destination, input.span());
self.visit_expression(&input.receiver, destination)
}
UnaryOperation::Square => {
// Only field type.
self.assert_field_type(destination, input.span());
self.visit_expression(&input.receiver, destination)
}
UnaryOperation::SquareRoot => {
// Only field type.
self.assert_field_type(destination, input.span());
self.visit_expression(&input.receiver, destination)
}
UnaryOperation::ToXCoordinate | UnaryOperation::ToYCoordinate => {
// Only field type.
self.assert_field_type(destination, input.span());
self.visit_expression(&input.receiver, &Some(Type::Group))
}
}
}
fn visit_unit(&mut self, input: &'a UnitExpression, _additional: &Self::AdditionalInput) -> Self::Output {
// Unit expression are only allowed inside a return statement.
if !self.scope_state.is_return {
self.emit_err(TypeCheckerError::unit_expression_only_in_return_statements(input.span()));
}
Some(Type::Unit)
}
}