Attach the cleanup to the `Temporary` instruction instead of to the
`TemporaryStorage` instruction. We create `TemporaryStorage`
instructions speculatively when creating an initializing expression, and
may overwrite those instructions with other instructions if it turns out
that a temporary is not required. Instead, wait until we finalize the
temporary and create a `Temporary` instruction to register the cleanup.
Based on #5948. A couple of tricky parts:
* When generating the C++ side of the thunk, we are given a pointer to
the location to emplace the return value. The only mechanism C++
provides to perform this emplacement is using placement `operator new`,
which requires a library function in the `<new>` header. We handle this
by declaring that library function ourselves, and rely on Clang not
actually needing a definition for it (which the standard library owns).
* On the Carbon side of the thunk, we want to form an initializing
expression as the result of the call. We don't have a way of expressing
in SemIR that an initializing expression performs its initialization by
storing through a pointer, so this PR adds a new initializing
instruction, `InPlaceInit`, to model an initialization that's performed
opaquely in-place.
Fix the algorithm for importing declarations in dependency order to
properly walk the dependency graph. Add the parent declaration of a
declaration to the dependency set so that we have a parent declaration
context to import a declaration into.
Fixes a crash when attempting to import a class whose parent is not
imported.
Instead of taking the complete text of the Clang diagnostic and using it
as the message portion of a Carbon diagnostic, generate the individual
pieces separately and pass them into the Carbon diagnostic
infrastructure.
* Clang's context lines are generated by running a custom "diagnostic
renderer" and tracking which lines it wants to print as context for a
given source location. When mapping from a C++ source location back to a
Carbon location, the Carbon `Loc` structure is now fully populated,
including filling in the context line and the column number.
* Clang's snippet is generated by running a custom diagnostic renderer
that is a cut-down version of the full text diagnostic renderer that
only prints a snippet. This is then attached to the Carbon diagnostic
manually as an override for the snippet we'd usually create.
We no longer repeat the file location twice on each diagnostic, and no
longer produce a bogus "in import" line for all locations coming from
clang that point arbitrarily to the first C++ import in the Carbon file.
The `[diagnostic kind]` marker is now displayed at the end of the
diagnostic message, not on a line of its own after the snippet.
Previously we would drop these diagnostics; now periodically flush them
to Carbon's diagnostics emitter. We flush them at the end of checking,
and also immediately before changing the set of diagnostic annotation
scopes, so that Clang diagnostics get properly annotated.
This exposes some double diagnostics being produced in situations where
Clang's name lookup logic would produce a diagnostic and we also
produced one. For access control issues, use the Carbon diagnostic, in
order to properly handle protected access. For ambiguity issues, use the
Clang diagnostic that produces helpful notes.
Also fix rendering of note diagnostics produced by Clang, by attaching
them to the prior error / warning diagnostic.
---------
Co-authored-by: Boaz Brickner <brickner@google.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Add a new type, `custom_layout_type`, representing a struct type whose
size, alignment, and field offsets can be manually controlled. Use this
as the object representation type for imported C++ class types (which
also includes struct and union types), allowing us to model C++ class
type layouts. In passing, also add support for incomplete C++ class
types, mapping them into incomplete Carbon class types.
Map C++ fields into Carbon field declarations, allowing direct access to
C++ fields from Carbon. So far, no support is added for base classes nor
anonymous struct or union declarations; those will be added in
subsequent PRs. Also, we don't map C++ access control into Carbon yet,
so all C++ fields are accessible regardless of their access control.
For now we still use a `struct_type` as the object representation for
empty C++ classes, in order to continue to support our existing tests
that convert `{}` to empty C++ class types. This is temporary and should
be removed once we support interop with C++ class initialization.
Change impls from `<interface>.impl` to `<self>.as.<interface>.impl`,
and *member* functions to `<parent scope>.<fn>` (non-member functions
exclude their parent scope). Stop special-casing builtin functions,
given the new naming scheme.
The purpose of this is to make it clearer when a member function is
being accessed and, if so, which member function. In particular, we
often access interface `Op` functions. The builtin function
special-casing was intended to help with that, but we still have lots of
`Op` functions. This particular approach should make the interactions
clearer.
This changes up queueing of block IDs a little because, in particular,
we need to process bodies of entities only after constants finish
processing. But, it should also result in less memory usage during
processing because it means we have less on the insts stack at any given
time, since we track a block rather than all instructions contained by
the block.
This switches from the `CollectNamesInBlock` approach for entities, to
instead traversing entities as they're encountered. For example, when
traversing constants, when a type is found, the entity will have its
block queued for processing.
This leads to a change in the traversal order, which affects
disambiguation done by numeric sequencing (since that's just showing the
traversal order).
This will allow for simpler "name based on name" logic. This is
something I plan to use for:
- impls: `<type>.as.<interface>.impl`
- functions: `<entity>.<member function>`
- Note an impl may be used as the entity for a bound function.
By naming the entities as they're encountered, I'll be able to rely on
the generated names rather than recalculating them.
To assist this, I'm also differentiating between the ambiguous and
disambiguated name. Otherwise, we could end up with things like
`<function>.<disambiguator>.<call>.<other disambiguator>`, where the
repeated disambiguator may not be necessary in order to get full
disambiguation. It's also a smaller delta from the current output.
Note, changing `Name` to a class felt appropriate given its shape. I was
also noticing that parts of its API were unused, and the class helps
detect unused private members.
---------
Co-authored-by: Geoff Romer <gromer@google.com>
The none.carbon min-prelude is not just an empty prelude, it also
prevents any prelude from being imported at all. So no import machinery
runs before the test, only the `package` statement from the prelude
would run.
Use the none.carbon min-prelude in a few tests that were specifying
`--no-prelude-import` to give it a trial run.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
All except
`toolchain/check/testdata/interop/cpp/function_param_int*.carbon` and
`toolchain/check/testdata/interop/cpp/function_return.carbon`.
Don't output SemIR for cases that are intended to fail.
This mirrors how imports work in general, that the imported declarations
shouldn't belong to the first referencing scope (particularly apparent
when referenced across multiple scopes). I think this was just an
oversight here.
People seemed receptive [on
#toolchain](https://discord.com/channels/655572317891461132/655578254970716160/1379196447827689553),
so proceeding.
For the two name conflicts, I've set it up so that there's a
"foo.carbon" and "foo_with_prelude.carbon", to indicate that the
no-prelude approach is preferred (with a shorter name).
Note min_prelude will require a little more work/thought, I want to
avoid adding `--custom-core` etc.
Richard Smith
Dana JansensandJon Ross-Perkins