mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-10-03 12:15:51 +01:00
Chandler Carruth
8be274cf60
Implement the toolchain side of proposal #7254, removing the `:!` binding syntax for generic and template parameters in favor of the keywords `generic`, `template`, and `runtime` plus contextual defaults for phase. For valid programs this is semantics-preserving: each binding resolves to the same phase, and produces the same SemIR, as it did under `:!`/`:`. The parser derives a binding's phase from its syntactic context plus any explicit phase keyword; new diagnostics and error recovery for misused keywords are described below. Implementation details for each component: - Lexer: remove the `:!` (`ColonExclaim`) token, move its virtual parse-node budget onto `:`, and add the `generic` and `runtime` keywords. - Parser: thread a `BindingContext` (`ExplicitParam`, `DeducedParam`, or `CompileTimeEntityParam`) from declaration introducers down through parameter lists to each binding pattern, using a one-token lookahead to distinguish a name-qualifier parameter list from a declaration's own final list. Parameters of a compile-time entity (`class`, `interface`, `constraint`, `choice`, `alias`, `export`, `namespace`) and deduced `[]` parameters default to checked generic; explicit function parameters and local bindings default to runtime. `HandleBindingPattern` resolves the phase from that context plus the keyword: a `generic` keyword needs no node of its own (the phase is carried by the binding's node kind), while a `runtime` keyword is preserved as a `RuntimeBindingName` node so `check` can name it in a diagnostic. A phase keyword that is merely redundant with the contextual default is diagnosed here, without invalidating the parse tree. - Check: a phase keyword that is invalid for its context (for example `runtime` on a checked-generic parameter) is diagnosed here, and recovers by building an error binding that still introduces the name so that later uses of it do not produce cascading errors. The removed `:!` syntax is now rejected as an ordinary parse error. The `form`/`:?`/`->?` ("extended types") portion of proposal #7254 is left for a separate change. Assisted-by: Claude Code
423 lines
15 KiB
Plaintext
423 lines
15 KiB
Plaintext
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/convert.carbon
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//
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// AUTOUPDATE
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// TIP: To test this file alone, run:
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// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/impl/lookup/impl_overlap.carbon
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// TIP: To dump output, run:
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// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/impl/lookup/impl_overlap.carbon
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// ============================================================================
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// Setup files
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// ============================================================================
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// --- interface_z.carbon
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library "[[@TEST_NAME]]";
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interface Z(T: type) {}
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// --- interface_z_with_impl.carbon
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library "[[@TEST_NAME]]";
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// Add an extra unused interface to bump `Z`'s id up so that it doesn't
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// accidentally match the id assigned to the imported copy of `Z`.
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interface Other(T: type) {}
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interface Z(T: type) {}
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final impl forall [T: type] T as Z(T) {}
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// --- type_d.carbon
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library "[[@TEST_NAME]]";
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class D(T: type) {}
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// ============================================================================
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// Test files
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// ============================================================================
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// --- final_impl_with_interface_generic_self.carbon
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library "[[@TEST_NAME]]";
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interface Z {}
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final impl forall [T: type] T as Z {}
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// --- final_impl_with_interface_concrete_self_same_file.carbon
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library "[[@TEST_NAME]]";
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interface Z {}
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class C {}
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final impl C as Z {}
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// --- final_impl_with_interface_concrete_self_same_file_defined_after.carbon
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library "[[@TEST_NAME]]";
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interface Z {}
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class C;
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final impl C as Z {}
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class C {}
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// --- final_impl_with_interface_concrete_self_from_other_file.carbon
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library "[[@TEST_NAME]]";
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import library "type_d";
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interface Z {}
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// The final impl is for a root self type from another file, but the interface
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// is in the same file, so this is valid.
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final impl D(()) as Z {}
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// --- final_impl_with_interface_symbolic_self_from_other_file.carbon
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library "[[@TEST_NAME]]";
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import library "type_d";
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interface Z {}
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// The root self type is from another file, but the interface is from this file.
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// This tests the self type being a symbolic type due to the type parameter T.
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final impl forall [T: type] D(T) as Z {}
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// --- fail_multiple_finals_overlap_with_interface.carbon
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library "[[@TEST_NAME]]";
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interface Z(T: type) {}
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final impl forall [T: type] T as Z(T) {}
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// The final impl here overlaps with the final impl above, but is not in a
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// match_first.
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//
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// CHECK:STDERR: fail_multiple_finals_overlap_with_interface.carbon:[[@LINE+7]]:1: error: `final impl` overlaps with `final impl` from same file outside a `match_first` block [FinalImplOverlapsSameFile]
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// CHECK:STDERR: final impl forall [T: type] T as Z(()) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_multiple_finals_overlap_with_interface.carbon:[[@LINE-8]]:1: note: other `final impl` here [FinalImplOverlapsSameFileNote]
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// CHECK:STDERR: final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl forall [T: type] T as Z(()) {}
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class C {}
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// The final impl here overlaps with the first final impl above, but is not in
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// a match_first.
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//
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// CHECK:STDERR: fail_multiple_finals_overlap_with_interface.carbon:[[@LINE+7]]:1: error: `final impl` overlaps with `final impl` from same file outside a `match_first` block [FinalImplOverlapsSameFile]
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// CHECK:STDERR: final impl C as Z({}) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_multiple_finals_overlap_with_interface.carbon:[[@LINE-22]]:1: note: other `final impl` here [FinalImplOverlapsSameFileNote]
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// CHECK:STDERR: final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl C as Z({}) {}
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// --- fail_multiple_finals_overlap_with_self_type.carbon
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library "[[@TEST_NAME]]";
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import library "interface_z";
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class C {}
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final impl C as Z(()) {}
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// The final impl here overlaps with the first final impl above, but is not in
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// a match_first.
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//
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// CHECK:STDERR: fail_multiple_finals_overlap_with_self_type.carbon:[[@LINE+7]]:1: error: `final impl` overlaps with `final impl` from same file outside a `match_first` block [FinalImplOverlapsSameFile]
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// CHECK:STDERR: final impl forall [T: type] C as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_multiple_finals_overlap_with_self_type.carbon:[[@LINE-8]]:1: note: other `final impl` here [FinalImplOverlapsSameFileNote]
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// CHECK:STDERR: final impl C as Z(()) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl forall [T: type] C as Z(T) {}
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// --- multiple_finals_with_nonoverlapping_with_interface.carbon
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library "[[@TEST_NAME]]";
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import library "type_d";
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interface Z {}
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// Two final impls for D as Z, but they are not overlapping so they are allowed
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// outside of match_first.
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final impl D(()) as Z {}
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final impl D({}) as Z {}
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// --- multiple_finals_with_nonoverlapping_with_self_type.carbon
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library "[[@TEST_NAME]]";
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import library "interface_z";
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class C {}
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// Two final impls for C as Z, but they are not overlapping so they are allowed
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// outside of match_first.
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final impl C as Z(()) {}
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final impl C as Z({}) {}
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// --- final_impl_with_root_self_type.carbon
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library "[[@TEST_NAME]]";
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import library "interface_z";
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class C(T: type) {}
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// Can provide a specialized final blanket impl for a type defined in the same
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// file.
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final impl forall [T: type] C(T) as Z(T) {}
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// --- fail_final_impl_with_both_interface_and_self_but_different_files.carbon
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library "[[@TEST_NAME]]";
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import library "interface_z_with_impl";
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class C {}
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// Can't write a final impl in both the interface's file and the root self
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// type's file (when they are different files).
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//
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// CHECK:STDERR: fail_final_impl_with_both_interface_and_self_but_different_files.carbon:[[@LINE+8]]:1: error: `final impl` overlaps with `final impl` from another file [FinalImplOverlapsDifferentFile]
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// CHECK:STDERR: final impl C as Z(()) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_final_impl_with_both_interface_and_self_but_different_files.carbon:[[@LINE-10]]:1: in import [InImport]
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// CHECK:STDERR: interface_z_with_impl.carbon:9:1: note: imported `final impl` here [FinalImplOverlapsDifferentFileNote]
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// CHECK:STDERR: final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl C as Z(()) {}
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// --- fail_final_overlaps_final_from_other_file.carbon
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library "[[@TEST_NAME]]";
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import library "interface_z_with_impl";
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class C {}
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// This final impl is overlapped by a final impl in the interface file, and you
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// can't write a final impl in two different files.
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//
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// CHECK:STDERR: fail_final_overlaps_final_from_other_file.carbon:[[@LINE+8]]:1: error: `final impl` overlaps with `final impl` from another file [FinalImplOverlapsDifferentFile]
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// CHECK:STDERR: final impl C as Z(C) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_final_overlaps_final_from_other_file.carbon:[[@LINE-10]]:1: in import [InImport]
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// CHECK:STDERR: interface_z_with_impl.carbon:9:1: note: imported `final impl` here [FinalImplOverlapsDifferentFileNote]
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// CHECK:STDERR: final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl C as Z(C) {}
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// --- fail_final_overlaps_non_final_from_other_file.carbon
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library "[[@TEST_NAME]]";
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import library "interface_z_with_impl";
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class C {}
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// This non-final impl is subsumed by a final impl in the interface file.
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//
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// CHECK:STDERR: fail_final_overlaps_non_final_from_other_file.carbon:[[@LINE+8]]:1: error: `impl` will never be used [ImplFinalOverlapsNonFinal]
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// CHECK:STDERR: impl C as Z(C) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_final_overlaps_non_final_from_other_file.carbon:[[@LINE-9]]:1: in import [InImport]
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// CHECK:STDERR: interface_z_with_impl.carbon:9:1: note: `final impl` declared here would always be used instead [ImplFinalOverlapsNonFinalNote]
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// CHECK:STDERR: final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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impl C as Z(C) {}
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// --- fail_final_root_self_type_not_defined.carbon
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library "[[@TEST_NAME]]";
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import library "interface_z";
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import library "type_d";
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class C;
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// The root type must be defined in the same library, not just declared.
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//
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// CHECK:STDERR: fail_final_root_self_type_not_defined.carbon:[[@LINE+4]]:1: error: `final impl` found in file that does not contain the root self type nor the interface definition [FinalImplInvalidFile]
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// CHECK:STDERR: final impl C as Z(()) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl C as Z(()) {}
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// --- fail_final_different_file_from_self_and_interface.carbon
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library "[[@TEST_NAME]]";
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import library "interface_z";
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import library "type_d";
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class C {}
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// Can't make a final impl that is not in the same file as the self type nor
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// the interface.
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//
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// CHECK:STDERR: fail_final_different_file_from_self_and_interface.carbon:[[@LINE+4]]:1: error: `final impl` found in file that does not contain the root self type nor the interface definition [FinalImplInvalidFile]
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// CHECK:STDERR: final impl D(C) as Z(()) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl D(C) as Z(()) {}
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// --- fail_final_different_file_from_self_and_interface_with_generic_self.carbon
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library "[[@TEST_NAME]]";
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import library "interface_z";
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class C {}
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// Can't make a final impl that is not in the same file as the self type nor
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// the interface.
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//
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// CHECK:STDERR: fail_final_different_file_from_self_and_interface_with_generic_self.carbon:[[@LINE+4]]:1: error: `final impl` found in file that does not contain the root self type nor the interface definition [FinalImplInvalidFile]
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// CHECK:STDERR: final impl forall [T: type] T as Z(C) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl forall [T: type] T as Z(C) {}
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// --- fail_final_overlaps_earlier_non_final_impl.carbon
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library "[[@TEST_NAME]]";
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interface Z(T: type) {}
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// CHECK:STDERR: fail_final_overlaps_earlier_non_final_impl.carbon:[[@LINE+3]]:1: error: `impl` will never be used [ImplFinalOverlapsNonFinal]
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// CHECK:STDERR: impl () as Z(()) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~
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impl () as Z(()) {}
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// CHECK:STDERR: fail_final_overlaps_earlier_non_final_impl.carbon:[[@LINE+4]]:1: note: `final impl` declared here would always be used instead [ImplFinalOverlapsNonFinalNote]
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// CHECK:STDERR: final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl forall [T: type] T as Z(T) {}
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// --- fail_final_overlaps_later_non_final_impl.carbon
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library "[[@TEST_NAME]]";
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interface Z(T: type) {}
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final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: fail_final_overlaps_later_non_final_impl.carbon:[[@LINE+7]]:1: error: `impl` will never be used [ImplFinalOverlapsNonFinal]
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// CHECK:STDERR: impl () as Z(()) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_final_overlaps_later_non_final_impl.carbon:[[@LINE-5]]:1: note: `final impl` declared here would always be used instead [ImplFinalOverlapsNonFinalNote]
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// CHECK:STDERR: final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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impl () as Z(()) {}
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// --- fail_final_overlaps_earlier_final_impl.carbon
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library "[[@TEST_NAME]]";
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interface Z(T: type) {}
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class C {}
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final impl C as Z(C) {}
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// CHECK:STDERR: fail_final_overlaps_earlier_final_impl.carbon:[[@LINE+7]]:1: error: `final impl` overlaps with `final impl` from same file outside a `match_first` block [FinalImplOverlapsSameFile]
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// CHECK:STDERR: final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_final_overlaps_earlier_final_impl.carbon:[[@LINE-5]]:1: note: other `final impl` here [FinalImplOverlapsSameFileNote]
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// CHECK:STDERR: final impl C as Z(C) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl forall [T: type] T as Z(T) {}
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// --- fail_final_overlaps_later_final_impl.carbon
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library "[[@TEST_NAME]]";
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interface Z(T: type) {}
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class C {}
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final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: fail_final_overlaps_later_final_impl.carbon:[[@LINE+7]]:1: error: `final impl` overlaps with `final impl` from same file outside a `match_first` block [FinalImplOverlapsSameFile]
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// CHECK:STDERR: final impl C as Z(C) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_final_overlaps_later_final_impl.carbon:[[@LINE-5]]:1: note: other `final impl` here [FinalImplOverlapsSameFileNote]
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// CHECK:STDERR: final impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl C as Z(C) {}
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// --- fail_non_final_type_structure_matches_non_final_impl.carbon
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library "[[@TEST_NAME]]";
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interface Z(T: type) {}
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interface Y {}
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impl forall [T: Y] T as Z(T) {}
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class C(T: type);
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// No diagnosis here as the type structure is unique.
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impl forall [T: type] T as Z(C(T)) {}
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// CHECK:STDERR: fail_non_final_type_structure_matches_non_final_impl.carbon:[[@LINE+7]]:1: error: found non-final `impl` with the same type structure as another non-final `impl` [ImplNonFinalSameTypeStructure]
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// CHECK:STDERR: impl forall [T: type] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_non_final_type_structure_matches_non_final_impl.carbon:[[@LINE-10]]:1: note: other `impl` here [ImplNonFinalSameTypeStructureNote]
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// CHECK:STDERR: impl forall [T: Y] T as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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impl forall [T: type] T as Z(T) {}
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// --- non_final_type_structure_same_shape_but_different_concrete_types.carbon
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library "[[@TEST_NAME]]";
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interface Z {}
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class C {}
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class D {}
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impl C as Z {}
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impl D as Z {}
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// --- partial_overlap_type_structure_of_non_final_impl.carbon
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library "[[@TEST_NAME]]";
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interface Z(T: type) {}
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impl forall [T: type] T as Z(T) {}
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class C {}
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// Partially overlaps the blanket impl, which is fine.
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final impl C as Z(C) {}
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class D {}
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// Partially overlaps the blanket impl, which is fine.
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impl D as Z(D) {}
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// --- fail_final_overlap_where_each_is_more_specific_than_the_other.carbon
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interface Z(T: type) {}
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class C(T: type) {}
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// This should be diagnosed as overlapping final impls outside a `match_first`.
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// The first impl is more specific in the interface constraint. The second is
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// more specific in the self type. They overlap for the query `C(()) as Z(())`
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// but neither impl is completely more specific than the other.
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final impl forall [T: type] C(T) as Z(()) {}
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// CHECK:STDERR: fail_final_overlap_where_each_is_more_specific_than_the_other.carbon:[[@LINE+7]]:1: error: `final impl` overlaps with `final impl` from same file outside a `match_first` block [FinalImplOverlapsSameFile]
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// CHECK:STDERR: final impl forall [T: type] C(()) as Z(T) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR: fail_final_overlap_where_each_is_more_specific_than_the_other.carbon:[[@LINE-4]]:1: note: other `final impl` here [FinalImplOverlapsSameFileNote]
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// CHECK:STDERR: final impl forall [T: type] C(T) as Z(()) {}
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// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// CHECK:STDERR:
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final impl forall [T: type] C(()) as Z(T) {}
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