Nicholas Bishop afd679129d Fix crash from accessing a Check::Context during lowering (#7335) ...

In generate_ast.cpp, an `CarbonExternalASTSource` is installed that has
a `Check::Context` pointer. During lowering, this `ExternalASTSource` is
still installed, and using it can cause a crash if the now-invalid
pointer is dereferenced.

Fix by adding a new `ReadOnlyASTSource` in sem_ir, and using that during
lowering.

`CarbonExternalASTSource` now inherits from `ReadOnlyASTSource` to avoid
some code duplication.

In generate_ast.cpp, we now always install a multiplex source, even if
there's only one child source. Clang internally keeps pointers to the
top-level `ExternalASTSource` installed via `setExternalSource`, and
those pointers aren't updated if `setExternalSource` is called again. By
using `MultiplexExternalSemaSource`, we can keep the top-level
`ExternalASTSource` pointer the same, and only update its children.

Using `MultiplexExternalSemaSource` this way requires a new constructor
and a method to modify its child sources; added a new LLVM patch adding
those.

https://github.com/carbon-language/carbon-lang/issues/7142

2026-06-12 18:05:19 +00:00

..

access.cpp

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

access.h

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

call.cpp

Improve ClangDeclStore ergonomics (#7311)

2026-06-05 20:49:34 +00:00

call.h

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

constant.cpp

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

constant.h

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

context.cpp

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

context.h

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

custom_type_mapping.cpp

Move C++ interop related check code files to a cpp dir (#6065)

2025-09-17 09:31:36 +00:00

custom_type_mapping.h

Move C++ interop related check code files to a cpp dir (#6065)

2025-09-17 09:31:36 +00:00

export.cpp

Fix crash from accessing a Check::Context during lowering (#7335)

2026-06-12 18:05:19 +00:00

export.h

Fix crash from accessing a Check::Context during lowering (#7335)

2026-06-12 18:05:19 +00:00

generate_ast.cpp

Fix crash from accessing a Check::Context during lowering (#7335)

2026-06-12 18:05:19 +00:00

generate_ast.h

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

impl_lookup.cpp

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

impl_lookup.h

adds a field to SemIR::Interface to indicate whether it is a core interface (#7091)

2026-04-24 17:33:23 +00:00

import.cpp

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

2026-06-10 15:30:43 +00:00

import.h

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

location.cpp

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

location.h

Improve diagnostics for overload resolution failure. (#6091)

2025-09-19 20:22:47 +00:00

macros.cpp

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

macros.h

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

operators.cpp

Don't form a bound method when calling a C++ operator. (#7345)

2026-06-11 21:49:20 +00:00

operators.h

Don't form a bound method when calling a C++ operator. (#7345)

2026-06-11 21:49:20 +00:00

overload_resolution.cpp

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

overload_resolution.h

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

thunk.cpp

Improve ClangDeclStore ergonomics (#7311)

2026-06-05 20:49:34 +00:00

thunk.h

Import C++ ref parameters as ref parameters (#6360)

2025-11-13 17:04:58 +00:00

type_mapping.cpp

Don't include expensive Clang headers in widely-included headers (#7319)

2026-06-07 16:27:22 +00:00

type_mapping.h

Add interop support for naming and "calling" C++ templates. (#6474)

2025-12-15 17:45:01 +00:00