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Replace :! binding syntax with phase keywords and contextual defaults (#7479)

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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
This commit is contained in:
Chandler Carruth
2026-07-11 01:22:44 +00:00
committed by GitHub
parent bf106c3b4b
commit 8be274cf60
482 changed files with 16917 additions and 16226 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/testdata/class/method/fail_generic_method.carbon
Vendored
+12 -12
View File
@@ -12,7 +12,7 @@
class I {}
class Class(T:! type) {
class Class(T: type) {
var a: T;
fn F(self, n: T);
}
@@ -20,18 +20,18 @@ class Class(T:! type) {
// TODO: The follow-on errors here aren't great. Investigate whether we can
// enter the scope anyway if the parameters don't match.
// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+15]]:17: error: type `<pattern for I>` of parameter 1 in redeclaration differs from previous parameter type `<pattern for type>` [RedeclParamDiffersType]
// CHECK:STDERR: fn Class(unused N:! I).F(unused self, unused n: T) {}
// CHECK:STDERR: ^~~~~
// CHECK:STDERR: fn Class(unused N: I).F(unused self, unused n: T) {}
// CHECK:STDERR: ^~~~
// CHECK:STDERR: fail_generic_method.carbon:[[@LINE-10]]:13: note: previous declaration's corresponding parameter here [RedeclParamPrevious]
// CHECK:STDERR: class Class(T:! type) {
// CHECK:STDERR: ^~~~~~~~
// CHECK:STDERR: class Class(T: type) {
// CHECK:STDERR: ^~~~~~~
// CHECK:STDERR:
// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+8]]:33: error: name `Self` not found [NameNotFound]
// CHECK:STDERR: fn Class(unused N:! I).F(unused self, unused n: T) {}
// CHECK:STDERR: ^~~~
// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+8]]:32: error: name `Self` not found [NameNotFound]
// CHECK:STDERR: fn Class(unused N: I).F(unused self, unused n: T) {}
// CHECK:STDERR: ^~~~
// CHECK:STDERR:
// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+4]]:49: error: name `T` not found [NameNotFound]
// CHECK:STDERR: fn Class(unused N:! I).F(unused self, unused n: T) {}
// CHECK:STDERR: ^
// CHECK:STDERR: fail_generic_method.carbon:[[@LINE+4]]:48: error: name `T` not found [NameNotFound]
// CHECK:STDERR: fn Class(unused N: I).F(unused self, unused n: T) {}
// CHECK:STDERR: ^
// CHECK:STDERR:
fn Class(unused N:! I).F(unused self, unused n: T) {}
fn Class(unused N: I).F(unused self, unused n: T) {}
toolchain/check/testdata/class/method/generic_method.carbon
Vendored
+11 -11
View File
@@ -12,12 +12,12 @@
// TIP: To dump output, run:
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/class/method/generic_method.carbon
class Class(T:! type) {
class Class(T: type) {
var a: T;
fn F(self, n: T);
}
fn Class(T:! type).F(unused self, unused n: T) {}
fn Class(T: type).F(unused self, unused n: T) {}
// CHECK:STDOUT: --- generic_method.carbon
@@ -63,9 +63,9 @@ fn Class(T:! type).F(unused self, unused n: T) {}
// CHECK:STDOUT: %Class.decl: %Class.type = class_decl @Class [concrete = constants.%Class.generic] {
// CHECK:STDOUT: %T.patt.loc15_14.1: %pattern_type.98f = symbolic_binding_pattern T, 0 [symbolic = %T.patt.loc15_14.2 (constants.%T.patt)]
// CHECK:STDOUT: } {
// CHECK:STDOUT: %.loc15_17.1: type = splice_block %.loc15_17.2 [concrete = type] {
// CHECK:STDOUT: %.loc15_16.1: type = splice_block %.loc15_16.2 [concrete = type] {
// CHECK:STDOUT: %.Self.frozen: %type = symbolic_binding .Self [symbolic_self = constants.%.Self.frozen]
// CHECK:STDOUT: %.loc15_17.2: type = type_literal type [concrete = type]
// CHECK:STDOUT: %.loc15_16.2: type = type_literal type [concrete = type]
// CHECK:STDOUT: }
// CHECK:STDOUT: %T.loc15_14.2: type = symbolic_binding T, 0 [symbolic = %T.loc15_14.1 (constants.%T)]
// CHECK:STDOUT: }
@@ -75,15 +75,15 @@ fn Class(T:! type).F(unused self, unused n: T) {}
// CHECK:STDOUT: %n.param_patt.loc20: @Class.F.%pattern_type.loc17_15 (%pattern_type.51d) = value_param_pattern [symbolic = %n.param_patt.loc17 (constants.%n.param_patt)]
// CHECK:STDOUT: %n.patt.loc20: @Class.F.%pattern_type.loc17_15 (%pattern_type.51d) = at_binding_pattern n, %n.param_patt.loc20 [symbolic = %n.patt.loc17 (constants.%n.patt)]
// CHECK:STDOUT: } {
// CHECK:STDOUT: %.loc20_14.1: type = splice_block %.loc20_14.2 [concrete = type] {
// CHECK:STDOUT: %.loc20_13.1: type = splice_block %.loc20_13.2 [concrete = type] {
// CHECK:STDOUT: %.Self.frozen: %type = symbolic_binding .Self [symbolic_self = constants.%.Self.frozen]
// CHECK:STDOUT: %.loc20_14.2: type = type_literal type [concrete = type]
// CHECK:STDOUT: %.loc20_13.2: type = type_literal type [concrete = type]
// CHECK:STDOUT: }
// CHECK:STDOUT: %T.loc20: type = symbolic_binding T, 0 [symbolic = @Class.%T.loc15_14.1 (constants.%T)]
// CHECK:STDOUT: %self.param.loc20: @Class.F.%Class (%Class) = value_param call_param0
// CHECK:STDOUT: %.loc20_29.1: type = splice_block %Self.ref.loc20 [symbolic = %Class (constants.%Class)] {
// CHECK:STDOUT: %.loc20_29.2: type = specific_constant constants.%Class, @Class(constants.%T) [symbolic = %Class (constants.%Class)]
// CHECK:STDOUT: %Self.ref.loc20: type = name_ref Self, %.loc20_29.2 [symbolic = %Class (constants.%Class)]
// CHECK:STDOUT: %.loc20_28.1: type = splice_block %Self.ref.loc20 [symbolic = %Class (constants.%Class)] {
// CHECK:STDOUT: %.loc20_28.2: type = specific_constant constants.%Class, @Class(constants.%T) [symbolic = %Class (constants.%Class)]
// CHECK:STDOUT: %Self.ref.loc20: type = name_ref Self, %.loc20_28.2 [symbolic = %Class (constants.%Class)]
// CHECK:STDOUT: }
// CHECK:STDOUT: %self.loc20: @Class.F.%Class (%Class) = wrapper_binding self, %self.param.loc20
// CHECK:STDOUT: %n.param.loc20: @Class.F.%T.loc17 (%T) = value_param call_param1
@@ -147,8 +147,8 @@ fn Class(T:! type).F(unused self, unused n: T) {}
// CHECK:STDOUT: %n.patt.loc17: @Class.F.%pattern_type.loc17_15 (%pattern_type.51d) = at_binding_pattern n, %n.param_patt.loc17 [symbolic = %n.patt.loc17 (constants.%n.patt)]
// CHECK:STDOUT:
// CHECK:STDOUT: !definition:
// CHECK:STDOUT: %require_complete.loc20_29: <witness> = require_complete_type %Class [symbolic = %require_complete.loc20_29 (constants.%require_complete.4d9)]
// CHECK:STDOUT: %require_complete.loc20_43: <witness> = require_complete_type %T.loc17 [symbolic = %require_complete.loc20_43 (constants.%require_complete.944)]
// CHECK:STDOUT: %require_complete.loc20_28: <witness> = require_complete_type %Class [symbolic = %require_complete.loc20_28 (constants.%require_complete.4d9)]
// CHECK:STDOUT: %require_complete.loc20_42: <witness> = require_complete_type %T.loc17 [symbolic = %require_complete.loc20_42 (constants.%require_complete.944)]
// CHECK:STDOUT:
// CHECK:STDOUT: fn(%self.param.loc20: @Class.F.%Class (%Class), %n.param.loc20: @Class.F.%T.loc17 (%T)) {
// CHECK:STDOUT: !entry:
toolchain/check/testdata/class/method/virtual.carbon
Vendored
+27 -27
View File
@@ -248,9 +248,9 @@ fn Derived.F(unused self) -> T2 {
library "[[@TEST_NAME]]";
// CHECK:STDERR: fail_generic_virtual_decl.carbon:[[@LINE+3]]:1: error: use of undefined generic function [MissingGenericFunctionDefinition]
// CHECK:STDERR: base class Base(T:! type) {
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~
base class Base(T:! type) {
// CHECK:STDERR: base class Base(T: type) {
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~
base class Base(T: type) {
// CHECK:STDERR: fail_generic_virtual_decl.carbon:[[@LINE+4]]:3: note: generic function declared here [MissingGenericFunctionDefinitionHere]
// CHECK:STDERR: virtual fn F(self);
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~
@@ -266,7 +266,7 @@ library "[[@TEST_NAME]]";
class T1 {
}
base class Base(T:! type) {
base class Base(T: type) {
virtual fn F(unused self, unused t: T) { }
}
@@ -330,29 +330,29 @@ library "[[@TEST_NAME]]";
base class T1 {
// CHECK:STDERR: fail_generic_virtual.carbon:[[@LINE+4]]:3: error: generic virtual function [GenericVirtual]
// CHECK:STDERR: virtual fn F[T:! type](self);
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// CHECK:STDERR: virtual fn F[T: type](self);
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
// CHECK:STDERR:
virtual fn F[T:! type](self);
virtual fn F[T: type](self);
}
// --- fail_generic_virtual_in_generic_class.carbon
library "[[@TEST_NAME]]";
base class T1(T:! type) {
base class T1(T: type) {
// CHECK:STDERR: fail_generic_virtual_in_generic_class.carbon:[[@LINE+4]]:3: error: generic virtual function [GenericVirtual]
// CHECK:STDERR: virtual fn F[T:! type](self);
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// CHECK:STDERR: virtual fn F[T: type](self);
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
// CHECK:STDERR:
virtual fn F[T:! type](self);
virtual fn F[T: type](self);
}
// --- generic_with_virtual.carbon
library "[[@TEST_NAME]]";
base class T1(T:! type) {
base class T1(T: type) {
//@dump-sem-ir-begin
virtual fn F(unused self) { }
//@dump-sem-ir-end
@@ -362,7 +362,7 @@ base class T1(T:! type) {
library "[[@TEST_NAME]]";
base class T1(T:! type) {
base class T1(T: type) {
//@dump-sem-ir-begin
virtual fn F(unused self, unused t: T) { }
//@dump-sem-ir-end
@@ -385,7 +385,7 @@ base class NonGenericBase {
virtual fn F2(unused self) { }
}
base class GenericDerived(T:! type) {
base class GenericDerived(T: type) {
extend base: NonGenericBase;
override fn F2(unused self) { }
virtual fn F3(unused self) { }
@@ -395,7 +395,7 @@ base class GenericDerived(T:! type) {
library "[[@TEST_NAME]]";
base class GenericBase(T:! type) {
base class GenericBase(T: type) {
virtual fn F1(unused self) { }
virtual fn F2(unused self) { }
}
@@ -412,7 +412,7 @@ base class NonGenericDerived {
library "[[@TEST_NAME]]";
base class Base(T:! type) {
base class Base(T: type) {
virtual fn F(unused self, unused t: Base(T)*) { }
}
class T1;
@@ -432,7 +432,7 @@ library "[[@TEST_NAME]]";
class T1;
class T2;
base class Base(T:! type) {
base class Base(T: type) {
virtual fn F(unused self, unused t: T1*) { }
}
@@ -454,10 +454,10 @@ class D1 {
library "[[@TEST_NAME]]";
abstract class Base(T:! type) {
abstract class Base(T: type) {
virtual fn F(unused self, unused t: T*) { }
}
class Derived(T:! type) {
class Derived(T: type) {
extend base: Base(T);
// CHECK:STDERR: fail_impl_generic_generic_mismatch.carbon:[[@LINE+7]]:37: note: initializing function parameter [InCallToFunctionParam]
// CHECK:STDERR: override fn F(unused self, unused t: T) { }
@@ -473,10 +473,10 @@ class Derived(T:! type) {
library "[[@TEST_NAME]]";
abstract class Base(T:! type) {
abstract class Base(T: type) {
virtual fn F(unused self, unused t: T) { }
}
class Derived(T:! type) {
class Derived(T: type) {
extend base: Base(T*);
//@dump-sem-ir-begin
override fn F(unused self, unused t: T*) { }
@@ -487,7 +487,7 @@ class Derived(T:! type) {
library "[[@TEST_NAME]]";
abstract class Base(T:! type) {
abstract class Base(T: type) {
abstract fn F(self);
}
@@ -502,7 +502,7 @@ class Derived {
library "[[@TEST_NAME]]";
base class Base(T:! type) {
base class Base(T: type) {
virtual fn F(unused self) { }
}
@@ -519,11 +519,11 @@ var v: Base(T1) = {};
library "[[@TEST_NAME]]";
base class T1(G1:! type) {
base class T1(G1: type) {
virtual fn F(unused self) { }
}
class T2(G2:! type) {
class T2(G2: type) {
extend base: T1(G2);
}
@@ -531,11 +531,11 @@ class T2(G2:! type) {
library "[[@TEST_NAME]]";
base class T1(G1:! type) {
base class T1(G1: type) {
virtual fn F(unused self) { }
}
class T2(G2:! type) {
class T2(G2: type) {
class T3 {
extend base: T1(G2);
}