Avoid symbolic witnesses for `.Self` in an impl decl (#7564)

mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-05 18:01:07 +01:00

Point symbolic witnesses into `.Self` written inside an impl decl at the
impl that is being declared. This is tricky because the impl does not
yet exist. So we use a new instruction `ImplSelfWitness` which _will_ be
replaced by the `ImplWitness` once it becomes available. The
`ImplSelfWitness` acts like a symbolic witness, except it does not
perform lookup, since we know which impl we will get a witness from.

This prevents us from finding other impls when performing lookups into
`.Self` in an impl decl, which produces incorrect/incoherent results.

This commit is contained in:

Dana Jansens

2026-07-29 16:25:23 +00:00

committed by

GitHub

parent 2ac425e591

commit f51c075f8b

94 changed files with 3221 additions and 2797 deletions

									
										toolchain/check/dump.cpp
									
		+1
		
												View File
												
				@@ -25,6 +25,7 @@

				#include "toolchain/parse/tree.h"

				#include "toolchain/sem_ir/dump.h"

				#include "toolchain/sem_ir/file.h"

				#include "toolchain/sem_ir/ids.h"

				namespace Carbon::Check {

Avoid symbolic witnesses for .Self in an impl decl (#7564)

Avoid symbolic witnesses for `.Self` in an impl decl (#7564)