carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-04 06:31:04 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Remove special case for returning value expressions by copy (#6052)

Browse Source 
When returning a value from a function whose return type has a by-copy
initializing representation, perform initialization like we do when the
return type has an in-place initializing representation. This makes our
SemIR representation more uniform, as the return expression will now
always be an initializing expression rather than a value expression, but
more importantly it means that attempts to return a non-copyable type by
value now fail, even if the type has a by-copy initializing
representation.

This catches a bunch of places where we were returning a value of an
unconstrained template parameter `T:! type`, which we were incorrectly
allowing because we didn't notice it was not copyable. Unfortunately
this then requires quite a few test updates.

Like #6034, this exposes a lowering issue where lowering crashes when
attempting to lower a specific copy operation for certain types; a
couple more tests are temporarily disabled here. An upcoming PR
dependent on this one will fix the issue and re-enable those tests.
This commit is contained in:
Richard Smith
2025-09-12 00:13:33 +00:00
committed by GitHub
parent 896ef4da0e
commit d60900cbeb
231 changed files with 8664 additions and 9042 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/testdata/interop/cpp/function/pointer.carbon
Vendored
+1 -1
View File
@@ -282,7 +282,7 @@ fn F() {
// CHECK:STDOUT: import Cpp//...
// CHECK:STDOUT: }
// CHECK:STDOUT: %S.decl: type = class_decl @S [concrete = constants.%S] {} {}
// CHECK:STDOUT: %Core.import_ref.de9: @ptr.as.Copy.impl.%ptr.as.Copy.impl.Op.type (%ptr.as.Copy.impl.Op.type.f23) = import_ref Core//prelude/parts/copy, loc32_31, loaded [symbolic = @ptr.as.Copy.impl.%ptr.as.Copy.impl.Op (constants.%ptr.as.Copy.impl.Op.abf)]
// CHECK:STDOUT: %Core.import_ref.de9: @ptr.as.Copy.impl.%ptr.as.Copy.impl.Op.type (%ptr.as.Copy.impl.Op.type.f23) = import_ref Core//prelude/parts/copy, loc36_31, loaded [symbolic = @ptr.as.Copy.impl.%ptr.as.Copy.impl.Op (constants.%ptr.as.Copy.impl.Op.abf)]
// CHECK:STDOUT: %Copy.impl_witness_table.a71 = impl_witness_table (%Core.import_ref.de9), @ptr.as.Copy.impl [concrete]
// CHECK:STDOUT: %foo.decl: %foo.type = fn_decl @foo [concrete = constants.%foo] {
// CHECK:STDOUT: <elided>