carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-05 09:11:05 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Only allow designators when parsing where __ = ... (#4304)

Browse Source 
Implements
[TODO](https://github.com/carbon-language/carbon-lang/pull/4275/files#r1751000646)
introduced in #4275 . Note that this enforces the restriction
syntactically in parse, following the
[design](https://github.com/carbon-language/carbon-lang/blob/trunk/docs/design/generics/details.md#rewrite-constraints).

---------

Co-authored-by: Josh L <josh11b@users.noreply.github.com>
This commit is contained in:
josh11b
2024-09-12 01:39:22 +00:00
committed by GitHub
co-authored by Josh L
parent de57c9988c
commit 35dfa5f03c
5 changed files with 234 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/diagnostics/diagnostic_kind.def
+1
View File
@@ -129,6 +129,7 @@ CARBON_DIAGNOSTIC_KIND(ExpectedAliasInitializer)
// Where requirement diagnostics.
CARBON_DIAGNOSTIC_KIND(ExpectedRequirementOperator)
CARBON_DIAGNOSTIC_KIND(RequirementEqualAfterNonDesignator)
// ============================================================================
// Semantics diagnostics
toolchain/parse/handle_requirement.cpp
+31 -9
View File
@@ -9,9 +9,23 @@
namespace Carbon::Parse {
auto HandleRequirementBegin(Context& context) -> void {
context.PopAndDiscardState();
// TODO: Peek ahead for `.designator = ...`, and give it special handling.
context.PushState(State::RequirementOperator);
auto state = context.PopState();
// Peek ahead for `.designator = ...`, and give it special handling.
if (context.PositionKind() == Lex::TokenKind::Period &&
context.PositionKind(Lookahead::NextToken) ==
Lex::TokenKind::Identifier &&
context.PositionKind(static_cast<Lookahead>(2)) ==
Lex::TokenKind::Equal) {
auto period = context.Consume();
context.AddNode(NodeKind::IdentifierName, context.Consume(),
/*has_error=*/false);
context.AddNode(NodeKind::DesignatorExpr, period, /*has_error=*/false);
state.token = context.Consume();
context.PushState(state, State::RequirementOperatorFinish);
} else {
context.PushState(State::RequirementOperator);
}
context.PushStateForExpr(PrecedenceGroup::ForRequirements());
}
@@ -19,14 +33,22 @@ auto HandleRequirementOperator(Context& context) -> void {
auto state = context.PopState();
switch (context.PositionKind()) {
case Lex::TokenKind::Impls: {
// Accept either `impls` or `==`
case Lex::TokenKind::Impls:
case Lex::TokenKind::EqualEqual:
break;
}
// Reject `=` since correct usage is consumed in `HandleRequirementBegin`.
case Lex::TokenKind::Equal: {
break;
}
case Lex::TokenKind::EqualEqual: {
break;
if (!state.has_error) {
CARBON_DIAGNOSTIC(
RequirementEqualAfterNonDesignator, Error,
"Requirement can only use `=` after `.member` designator.");
context.emitter().Emit(*context.position(),
RequirementEqualAfterNonDesignator);
}
context.ReturnErrorOnState();
return;
}
default: {
if (!state.has_error) {
toolchain/parse/state.def
+4
View File
@@ -618,6 +618,10 @@ CARBON_PARSE_STATE(IfExprFinish)
// an expression.
// TODO: Also a `require` declaration?
//
// expr where .designator = ...
// ^~~~~~~~~~~~~
// 1. Expr
// 2. RequirementOperatorFinish
// expr where ...
// ^
// 1. Expr
toolchain/parse/testdata/where_expr/fail_rewrite.carbon
Vendored
+197
View File
@@ -0,0 +1,197 @@
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
// AUTOUPDATE
// TIP: To test this file alone, run:
// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/parse/testdata/where_expr/fail_rewrite.carbon
// TIP: To dump output, run:
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/parse/testdata/where_expr/fail_rewrite.carbon
// Tests for reporting errors when a rewrite requirement doesn't follow
// `where .designator = rewrite`.
// --- fail_not_designator.carbon
// CHECK:STDERR: fail_not_designator.carbon:[[@LINE+4]]:37: ERROR: Requirement can only use `=` after `.member` designator.
// CHECK:STDERR: fn NotDesignator(T:! type where i32 = .U);
// CHECK:STDERR: ^
// CHECK:STDERR:
fn NotDesignator(T:! type where i32 = .U);
// --- fail_designator_in_parens.carbon
// CHECK:STDERR: fail_designator_in_parens.carbon:[[@LINE+4]]:40: ERROR: Requirement can only use `=` after `.member` designator.
// CHECK:STDERR: fn DesignatorInParens(V:! I where (.J) = bool);
// CHECK:STDERR: ^
// CHECK:STDERR:
fn DesignatorInParens(V:! I where (.J) = bool);
// --- fail_dot_self.carbon
// CHECK:STDERR: fail_dot_self.carbon:[[@LINE+4]]:30: ERROR: Requirement can only use `=` after `.member` designator.
// CHECK:STDERR: fn DotSelf(W:! K where .Self = f32);
// CHECK:STDERR: ^
// CHECK:STDERR:
fn DotSelf(W:! K where .Self = f32);
// --- fail_dot_keyword.carbon
// CHECK:STDERR: fail_dot_keyword.carbon:[[@LINE+4]]:28: ERROR: Expected identifier or `Self` after `.`.
// CHECK:STDERR: fn DotKeyword(W:! K where .and = u8);
// CHECK:STDERR: ^~~
// CHECK:STDERR:
fn DotKeyword(W:! K where .and = u8);
// --- fail_postfix_after_designator.carbon
// CHECK:STDERR: fail_postfix_after_designator.carbon:[[@LINE+4]]:43: ERROR: Requirement can only use `=` after `.member` designator.
// CHECK:STDERR: fn PostfixAfterDesignator(X:! L where .M* = u64*);
// CHECK:STDERR: ^
// CHECK:STDERR:
fn PostfixAfterDesignator(X:! L where .M* = u64*);
// --- fail_binary_op_after_designator.carbon
// CHECK:STDERR: fail_binary_op_after_designator.carbon:[[@LINE+4]]:48: ERROR: Requirement can only use `=` after `.member` designator.
// CHECK:STDERR: fn BinaryOpAfterDesignator(Y:! N where .O + .P = {});
// CHECK:STDERR: ^
// CHECK:STDERR:
fn BinaryOpAfterDesignator(Y:! N where .O + .P = {});
// --- fail_after_and.carbon
// CHECK:STDERR: fail_after_and.carbon:[[@LINE+3]]:43: ERROR: Requirement can only use `=` after `.member` designator.
// CHECK:STDERR: fn AfterAnd(Z:! Q where .R impls S and () = .A);
// CHECK:STDERR: ^
fn AfterAnd(Z:! Q where .R impls S and () = .A);
// CHECK:STDOUT: - filename: fail_not_designator.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'NotDesignator'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'T'},
// CHECK:STDOUT: {kind: 'TypeTypeLiteral', text: 'type'},
// CHECK:STDOUT: {kind: 'WhereOperand', text: 'where', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 4},
// CHECK:STDOUT: {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 6},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', has_error: yes, subtree_size: 8},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 11},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: fail_designator_in_parens.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'DesignatorInParens'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'V'},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'I'},
// CHECK:STDOUT: {kind: 'WhereOperand', text: 'where', subtree_size: 2},
// CHECK:STDOUT: {kind: 'ParenExprStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'J'},
// CHECK:STDOUT: {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
// CHECK:STDOUT: {kind: 'ParenExpr', text: ')', subtree_size: 4},
// CHECK:STDOUT: {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 7},
// CHECK:STDOUT: {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 9},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', has_error: yes, subtree_size: 11},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 14},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: fail_dot_self.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'DotSelf'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'W'},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'K'},
// CHECK:STDOUT: {kind: 'WhereOperand', text: 'where', subtree_size: 2},
// CHECK:STDOUT: {kind: 'SelfTypeName', text: 'Self'},
// CHECK:STDOUT: {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
// CHECK:STDOUT: {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 5},
// CHECK:STDOUT: {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 7},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', has_error: yes, subtree_size: 9},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 12},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: fail_dot_keyword.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'DotKeyword'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'W'},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'K'},
// CHECK:STDOUT: {kind: 'WhereOperand', text: 'where', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'and', has_error: yes},
// CHECK:STDOUT: {kind: 'DesignatorExpr', text: '.', has_error: yes, subtree_size: 2},
// CHECK:STDOUT: {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 5},
// CHECK:STDOUT: {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 7},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', has_error: yes, subtree_size: 9},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 12},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: fail_postfix_after_designator.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'PostfixAfterDesignator'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'X'},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'L'},
// CHECK:STDOUT: {kind: 'WhereOperand', text: 'where', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'M'},
// CHECK:STDOUT: {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
// CHECK:STDOUT: {kind: 'PostfixOperatorStar', text: '*', subtree_size: 3},
// CHECK:STDOUT: {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 6},
// CHECK:STDOUT: {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 8},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', has_error: yes, subtree_size: 10},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 13},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: fail_binary_op_after_designator.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'BinaryOpAfterDesignator'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'Y'},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'N'},
// CHECK:STDOUT: {kind: 'WhereOperand', text: 'where', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'O'},
// CHECK:STDOUT: {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'P'},
// CHECK:STDOUT: {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
// CHECK:STDOUT: {kind: 'InfixOperatorPlus', text: '+', subtree_size: 5},
// CHECK:STDOUT: {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 8},
// CHECK:STDOUT: {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 10},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', has_error: yes, subtree_size: 12},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 15},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
// CHECK:STDOUT: - filename: fail_after_and.carbon
// CHECK:STDOUT: parse_tree: [
// CHECK:STDOUT: {kind: 'FileStart', text: ''},
// CHECK:STDOUT: {kind: 'FunctionIntroducer', text: 'fn'},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'AfterAnd'},
// CHECK:STDOUT: {kind: 'TuplePatternStart', text: '('},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'Z'},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'Q'},
// CHECK:STDOUT: {kind: 'WhereOperand', text: 'where', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'R'},
// CHECK:STDOUT: {kind: 'DesignatorExpr', text: '.', subtree_size: 2},
// CHECK:STDOUT: {kind: 'IdentifierNameExpr', text: 'S'},
// CHECK:STDOUT: {kind: 'RequirementImpls', text: 'impls', subtree_size: 4},
// CHECK:STDOUT: {kind: 'RequirementAnd', text: 'and'},
// CHECK:STDOUT: {kind: 'TupleLiteralStart', text: '('},
// CHECK:STDOUT: {kind: 'TupleLiteral', text: ')', subtree_size: 2},
// CHECK:STDOUT: {kind: 'WhereExpr', text: 'where', has_error: yes, subtree_size: 10},
// CHECK:STDOUT: {kind: 'CompileTimeBindingPattern', text: ':!', has_error: yes, subtree_size: 12},
// CHECK:STDOUT: {kind: 'TuplePattern', text: ')', has_error: yes, subtree_size: 14},
// CHECK:STDOUT: {kind: 'FunctionDecl', text: ';', subtree_size: 17},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]
toolchain/parse/typed_nodes.h
+1 -2
View File
@@ -1037,8 +1037,7 @@ struct DesignatorExpr {
struct RequirementEqual {
static constexpr auto Kind = NodeKind::RequirementEqual.Define(
{.category = NodeCategory::Requirement, .child_count = 2});
// TODO: Enforce that the lhs is always a DesignatorExpr.
AnyExprId lhs;
DesignatorExprId lhs;
Lex::EqualTokenIndex token;
AnyExprId rhs;
};