carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-09-24 21:30:12 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Export methods taking self as const member functions (#7577)

Browse Source 
A method declared with `self` does not modify the object, but it was
exported to C++ as a non-const member function, so calling it on a const
reference would fail.

```carbon
class C {
  fn Get(self);
}

inline Cpp '''
void F(const Carbon::C& c) {
  c.Get();
}
''';
```
```
error: 'this' argument to member function 'Get' has type 'const Carbon::C', but function is not marked const
```

Import already maps `f() const` to `fn f(self)`, and this PR implements
the same behavior for exporting. No ref-qualifier is added, since that
maps to `ref self`, so that is unchanged.

`GetThisArg()` now builds `this` from the method instead of the parent
record, so that it picks up the method's const-qualifier.
This commit is contained in:
arhwx
2026-07-29 17:28:54 +00:00
committed by GitHub
parent f51c075f8b
commit 6ea2087f0a
4 changed files with 58 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/lower/testdata/interop/cpp/class/import/dynamic.carbon
Vendored
+2 -2
View File
@@ -63,7 +63,7 @@ fn DoThing() {
// CHECK:STDOUT:
// CHECK:STDOUT: @_ZTV4Base = available_externally constant { [4 x ptr] } { [4 x ptr] [ptr null, ptr @_ZTI4Base, ptr @_ZN11FurtherBase17further_base_funcEv, ptr @_ZNR4Base4funcEv] }, align 8
// CHECK:STDOUT: @_ZTV11FurtherBase = available_externally constant { [3 x ptr] } { [3 x ptr] [ptr null, ptr @_ZTI11FurtherBase, ptr @_ZN11FurtherBase17further_base_funcEv] }, align 8
// CHECK:STDOUT: @_ZTVN6Carbon7DerivedE = linkonce_odr dso_local constant { [5 x ptr] } { [5 x ptr] [ptr null, ptr @_ZTIN6Carbon7DerivedE, ptr @_ZN11FurtherBase17further_base_funcEv, ptr @_ZNR6Carbon7Derived4funcEv, ptr @_ZN6Carbon7Derived10other_funcEv] }, comdat, align 8
// CHECK:STDOUT: @_ZTVN6Carbon7DerivedE = linkonce_odr dso_local constant { [5 x ptr] } { [5 x ptr] [ptr null, ptr @_ZTIN6Carbon7DerivedE, ptr @_ZN11FurtherBase17further_base_funcEv, ptr @_ZNR6Carbon7Derived4funcEv, ptr @_ZNK6Carbon7Derived10other_funcEv] }, comdat, align 8
// CHECK:STDOUT: @_ZTI4Base = external constant ptr
// CHECK:STDOUT: @_ZTI11FurtherBase = external constant ptr
// CHECK:STDOUT: @_ZTIN6Carbon7DerivedE = linkonce_odr dso_local constant { ptr, ptr, ptr } { ptr getelementptr inbounds (ptr, ptr @_ZTVN10__cxxabiv120__si_class_type_infoE, i64 2), ptr @_ZTSN6Carbon7DerivedE, ptr @_ZTI4Base }, comdat, align 8
@@ -180,7 +180,7 @@ fn DoThing() {
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: ; Function Attrs: alwaysinline mustprogress nounwind uwtable
// CHECK:STDOUT: define internal void @_ZN6Carbon7Derived10other_funcEv(ptr noundef nonnull align 8 dereferenceable(12) %this) unnamed_addr #4 align 2 {
// CHECK:STDOUT: define internal void @_ZNK6Carbon7Derived10other_funcEv(ptr noundef nonnull align 8 dereferenceable(12) %this) unnamed_addr #4 align 2 {
// CHECK:STDOUT: entry:
// CHECK:STDOUT: %this.addr = alloca ptr, align 8
// CHECK:STDOUT: store ptr %this, ptr %this.addr, align 8, !tbaa !59