carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-09-24 20:20:10 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Move self to the explicit () parameter list (proposal #7016) (#7272)

Browse Source 
Implements proposal #7016: `self` moves from the deduced implicit list
(`fn F[self: Self]()`) to the front of the explicit list. Its type may
be written explicitly (`fn F(self: Self)`) or omitted, in which case it
defaults to `Self` (`fn F(self)`, `fn F(ref self)`); `self` in the
implicit list is rejected.

Throughout checking, `self` is modeled as the first explicit parameter.
Because a method is just a function whose first parameter is `self`, it
can also be called as an ordinary function with the receiver passed
explicitly (`Type.M(obj, ...)`), not only as `obj.M(...)`. A new
`SemIR::CallArgParamPatterns` helper chooses the parameters matched
against the explicit arguments, excluding a leading `self` only when it
is supplied as a method-call receiver; arity checking, conversion, and
generic deduction use it. The resulting SemIR and lowering are
unchanged: `self` is still `call_param0`, and witnesses, thunks, and
vtables are unaffected.

An omitted `self` type is parsed as a `SelfBindingPattern` node with no
type expression; checking synthesizes the `Self` type so it behaves
exactly like `self: Self`. However, the exact spelling used must match
between a forward declaration and a definition, following #3763's rules
around declaration matching.

Generated functions, thunks, and C++ interop import/export build `self`
as the first explicit parameter, and the `self`-type override (e.g.
Derived->Base for a virtual override) applies to the explicit `self`.
Placement is validated by new diagnostics: `SelfInImplicitParamList`,
`SelfNotFirstParam`, and `SelfOutsideParamList`. The benchmark source
generator and the documentation adopt the `(self)` shorthand; the
prelude, the examples, and the test data are migrated in the following
commits.

Assisted-by: Claude Code with Claude Opus 4.7

---------

Co-authored-by: josh11b <15258583+josh11b@users.noreply.github.com>
This commit is contained in:
Chandler Carruth
2026-06-10 15:30:43 +00:00
committed by GitHub
co-authored by josh11b
parent fb05da761f
commit 7871237c15
296 changed files with 6101 additions and 4899 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/testdata/impl/fail_impl_as_scope.carbon
Vendored
+24 -23
View File
@@ -48,7 +48,7 @@ library "[[@TEST_NAME]]";
interface Z {
fn Zero();
fn Method[self: Self]();
fn Method(self);
// CHECK:STDERR: fail_impl_as_self_interface.carbon:[[@LINE+4]]:9: error: `impl as` can only be used in a class [ImplAsOutsideClass]
// CHECK:STDERR: impl as Z {
@@ -56,14 +56,14 @@ interface Z {
// CHECK:STDERR:
impl as Z {
fn Zero() {}
fn Method[unused self: Self]() {}
fn Method(unused self) {}
}
}
class Point {
impl as Z {
fn Zero() {}
fn Method[unused self: Self]() {}
fn Method(unused self) {}
}
}
@@ -99,6 +99,7 @@ class X {
}
}
// CHECK:STDOUT: --- fail_impl_as_file_scope.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
@@ -312,13 +313,13 @@ class X {
// CHECK:STDOUT: %self.param_patt: @Z.WithSelf.Method.%pattern_type (%pattern_type.52a) = value_param_pattern [concrete]
// CHECK:STDOUT: %self.patt: @Z.WithSelf.Method.%pattern_type (%pattern_type.52a) = at_binding_pattern self, %self.param_patt [concrete]
// CHECK:STDOUT: } {
// CHECK:STDOUT: %self.param: @Z.WithSelf.Method.%Self.as_type.loc5_19.1 (%Self.as_type.0cf) = value_param call_param0
// CHECK:STDOUT: %.loc5_19.1: type = splice_block %.loc5_19.2 [symbolic = %Self.as_type.loc5_19.1 (constants.%Self.as_type.0cf)] {
// CHECK:STDOUT: %self.param: @Z.WithSelf.Method.%Self.as_type.loc5_13.1 (%Self.as_type.0cf) = value_param call_param0
// CHECK:STDOUT: %.loc5_13.1: type = splice_block %.loc5_13.2 [symbolic = %Self.as_type.loc5_13.1 (constants.%Self.as_type.0cf)] {
// CHECK:STDOUT: %Self.ref: %Z.type = name_ref Self, @Z.%Self [symbolic = %Self (constants.%Self.cb6)]
// CHECK:STDOUT: %Self.as_type.loc5_19.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc5_19.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %.loc5_19.2: type = converted %Self.ref, %Self.as_type.loc5_19.2 [symbolic = %Self.as_type.loc5_19.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %Self.as_type.loc5_13.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc5_13.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %.loc5_13.2: type = converted %Self.ref, %Self.as_type.loc5_13.2 [symbolic = %Self.as_type.loc5_13.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: }
// CHECK:STDOUT: %self: @Z.WithSelf.Method.%Self.as_type.loc5_19.1 (%Self.as_type.0cf) = value_binding self, %self.param
// CHECK:STDOUT: %self: @Z.WithSelf.Method.%Self.as_type.loc5_13.1 (%Self.as_type.0cf) = value_binding self, %self.param
// CHECK:STDOUT: }
// CHECK:STDOUT: %assoc1: %Z.assoc_type = assoc_entity element1, %Z.WithSelf.Method.decl [concrete = constants.%assoc1]
// CHECK:STDOUT: impl_decl @<error>.as.Z.impl [concrete] {} {
@@ -350,13 +351,13 @@ class X {
// CHECK:STDOUT: %self.param_patt: @<error>.as.Z.impl.Method.%pattern_type (%pattern_type.52a) = value_param_pattern [concrete]
// CHECK:STDOUT: %self.patt: @<error>.as.Z.impl.Method.%pattern_type (%pattern_type.52a) = at_binding_pattern self, %self.param_patt [concrete]
// CHECK:STDOUT: } {
// CHECK:STDOUT: %self.param: @<error>.as.Z.impl.Method.%Self.as_type.loc13_28.1 (%Self.as_type.0cf) = value_param call_param0
// CHECK:STDOUT: %.loc13_28.1: type = splice_block %.loc13_28.2 [symbolic = %Self.as_type.loc13_28.1 (constants.%Self.as_type.0cf)] {
// CHECK:STDOUT: %self.param: @<error>.as.Z.impl.Method.%Self.as_type.loc13_22.1 (%Self.as_type.0cf) = value_param call_param0
// CHECK:STDOUT: %.loc13_22.1: type = splice_block %.loc13_22.2 [symbolic = %Self.as_type.loc13_22.1 (constants.%Self.as_type.0cf)] {
// CHECK:STDOUT: %Self.ref: %Z.type = name_ref Self, @Z.%Self [symbolic = %Self (constants.%Self.cb6)]
// CHECK:STDOUT: %Self.as_type.loc13_28.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc13_28.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %.loc13_28.2: type = converted %Self.ref, %Self.as_type.loc13_28.2 [symbolic = %Self.as_type.loc13_28.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %Self.as_type.loc13_22.2: type = facet_access_type %Self.ref [symbolic = %Self.as_type.loc13_22.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %.loc13_22.2: type = converted %Self.ref, %Self.as_type.loc13_22.2 [symbolic = %Self.as_type.loc13_22.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: }
// CHECK:STDOUT: %self: @<error>.as.Z.impl.Method.%Self.as_type.loc13_28.1 (%Self.as_type.0cf) = value_binding self, %self.param
// CHECK:STDOUT: %self: @<error>.as.Z.impl.Method.%Self.as_type.loc13_22.1 (%Self.as_type.0cf) = value_binding self, %self.param
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: !members:
@@ -406,10 +407,10 @@ class X {
// CHECK:STDOUT:
// CHECK:STDOUT: generic fn @Z.WithSelf.Method(@Z.%Self: %Z.type) {
// CHECK:STDOUT: %Self: %Z.type = symbolic_binding Self, 0 [symbolic = %Self (constants.%Self.cb6)]
// CHECK:STDOUT: %Self.as_type.loc5_19.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc5_19.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %pattern_type: type = pattern_type %Self.as_type.loc5_19.1 [symbolic = %pattern_type (constants.%pattern_type.52a)]
// CHECK:STDOUT: %Self.as_type.loc5_13.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc5_13.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %pattern_type: type = pattern_type %Self.as_type.loc5_13.1 [symbolic = %pattern_type (constants.%pattern_type.52a)]
// CHECK:STDOUT:
// CHECK:STDOUT: fn(%self.param: @Z.WithSelf.Method.%Self.as_type.loc5_19.1 (%Self.as_type.0cf));
// CHECK:STDOUT: fn(%self.param: @Z.WithSelf.Method.%Self.as_type.loc5_13.1 (%Self.as_type.0cf));
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: generic fn @<error>.as.Z.impl.Zero(@Z.%Self: %Z.type) {
@@ -423,13 +424,13 @@ class X {
// CHECK:STDOUT:
// CHECK:STDOUT: generic fn @<error>.as.Z.impl.Method(@Z.%Self: %Z.type) {
// CHECK:STDOUT: %Self: %Z.type = symbolic_binding Self, 0 [symbolic = %Self (constants.%Self.cb6)]
// CHECK:STDOUT: %Self.as_type.loc13_28.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc13_28.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %pattern_type: type = pattern_type %Self.as_type.loc13_28.1 [symbolic = %pattern_type (constants.%pattern_type.52a)]
// CHECK:STDOUT: %Self.as_type.loc13_22.1: type = facet_access_type %Self [symbolic = %Self.as_type.loc13_22.1 (constants.%Self.as_type.0cf)]
// CHECK:STDOUT: %pattern_type: type = pattern_type %Self.as_type.loc13_22.1 [symbolic = %pattern_type (constants.%pattern_type.52a)]
// CHECK:STDOUT:
// CHECK:STDOUT: !definition:
// CHECK:STDOUT: %require_complete: <witness> = require_complete_type %Self.as_type.loc13_28.1 [symbolic = %require_complete (constants.%require_complete)]
// CHECK:STDOUT: %require_complete: <witness> = require_complete_type %Self.as_type.loc13_22.1 [symbolic = %require_complete (constants.%require_complete)]
// CHECK:STDOUT:
// CHECK:STDOUT: fn(%self.param: @<error>.as.Z.impl.Method.%Self.as_type.loc13_28.1 (%Self.as_type.0cf)) {
// CHECK:STDOUT: fn(%self.param: @<error>.as.Z.impl.Method.%Self.as_type.loc13_22.1 (%Self.as_type.0cf)) {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT: return
// CHECK:STDOUT: }
@@ -490,7 +491,7 @@ class X {
// CHECK:STDOUT:
// CHECK:STDOUT: specific @Z.WithSelf.Method(constants.%Self.cb6) {
// CHECK:STDOUT: %Self => constants.%Self.cb6
// CHECK:STDOUT: %Self.as_type.loc5_19.1 => constants.%Self.as_type.0cf
// CHECK:STDOUT: %Self.as_type.loc5_13.1 => constants.%Self.as_type.0cf
// CHECK:STDOUT: %pattern_type => constants.%pattern_type.52a
// CHECK:STDOUT: }
// CHECK:STDOUT:
@@ -507,7 +508,7 @@ class X {
// CHECK:STDOUT:
// CHECK:STDOUT: specific @<error>.as.Z.impl.Method(constants.%Self.cb6) {
// CHECK:STDOUT: %Self => constants.%Self.cb6
// CHECK:STDOUT: %Self.as_type.loc13_28.1 => constants.%Self.as_type.0cf
// CHECK:STDOUT: %Self.as_type.loc13_22.1 => constants.%Self.as_type.0cf
// CHECK:STDOUT: %pattern_type => constants.%pattern_type.52a
// CHECK:STDOUT: }
// CHECK:STDOUT:
@@ -524,7 +525,7 @@ class X {
// CHECK:STDOUT:
// CHECK:STDOUT: specific @Z.WithSelf.Method(constants.%Z.facet) {
// CHECK:STDOUT: %Self => constants.%Z.facet
// CHECK:STDOUT: %Self.as_type.loc5_19.1 => constants.%Point
// CHECK:STDOUT: %Self.as_type.loc5_13.1 => constants.%Point
// CHECK:STDOUT: %pattern_type => constants.%pattern_type.9d8
// CHECK:STDOUT: }
// CHECK:STDOUT: