Any non-extend require decls must be satisfied when the impl definition
starts, but they are not checked. We only check for require decls in the
target interface being impld.
This commit adds support for range-based for loops using C++ types. It's
currently limited to detecting that `r.begin()` and `r.end()` are
available. We should be able to add full support for methods after #7181
is merged.
Support for ADL is still a work-in-progress, and will be added at a
later time.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Implement the alias rules from proposal #5389, wherein an alias is
permitted so long as the target has a constant value. While that
proposal is not yet accepted, this seems like a reasonable basis for
further iteration, and will be useful for the examples we're currently
pursuing.
Also cleans up redundant code in the `sem_ir` dump methods that I missed
initially. Now we share as much logic as we can for dumping the non-ID
and ID components.
Assisted-by: Antigravity with Gemini
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
This correctly renders the vtable in SemIR, including allowing overrides
in
Carbon-derived-from-C++ classes.
It doesn't work in lowering because clang walks the methods of the
CXXRecordDecl - and we currently don't export anything into the
CXXRecordDecl's methods (we do export the fields) - so that's next.
This also doesn't teach Clang to affirmatively emit the vtable
regardless of the types use in C++ code - or to have Carbon use the
vtable in an object's initialization.
Roundtrip (export/reimport) class declarations
The remapping was previously implemented using name_scopes, which aren't
created for class declarations, only definitions - causing the reimport
to import a fresh copy of the type that mismatched with the original (as
seen in the test baseline).
By changing the mapping to use the reverse part of the clang_decls
mapping this should generalize better (& we probably should further
migrate to that mapping). Though it did trip over some issue with
exactly which instruction is used as the key in the clang_decls map -
this change moves towards standardizing on the first decl id of the
class as its map key.
We were treating ImplWitnessAccess as a concrete type, but that is
incorrect if its accessing a symbolic type value. This results in
concrete impl lookup queries failing to match a generic impl that is
built with a symbolic ImplWitnessAccess in its type structure, when the
query does not have the equivalent ImplWitnessAccess in its own type
structure.
We need to look in the top level facet being accessed through
ImplWitnessAccess for witnesses, such as in `T:! Z where .Z1 impls Y`
where `T` provides the witness for `T.Z1 as Y`. But we also need to look
in the facet type of the ImplWitnessAccess for witnesses, such as in
`T:! Z` for `interface Z { let Z1:! Y }`, where `T.Z1` provides the
witness for `T.Z1 as Y`.
To support that we give TypeIterator an iteration step for
ImplWitnessAccess before recursing into it, like we do for FacetValue.
While doing this, we make TypeIterator more recursive, by making less
special casing around the step from one inst into the next. Instead of
eagerly finding a SymbolicType, we consistently recurse back into the
big switch statement and have it decide the next iteration step. This
allows it to recurse into instructions like ImplWitnessAccess and
FacetValue in a consistent manner.
`param.carbon` already tests cleanup when passing a class value produced
by
`C.Make()` to a `var` parameter. Add the corresponding struct literal
case,
`F({})`, matching the repro from #7168
The issue appears to already be fixed on main so this adds a test to
make sure
the compiler keeps calling `Core.Destroy` for the temporary value after
`F({})`
returns
Closes#7168
Assisted-by: Qwen 3.6
https://carbon.compiler-explorer.com/z/88K9Kh5Wo shows the program
exiting with a garbage value copied from uninitialized memory.
This PR modifies `lower` to detect if the function lowered is the
entry point and doesn't specify a return type. If so, it emits
different LLVM IR to return int32 0, and modifies the lowered
function signature to match the int32 return type.
This enables searching facets like `T:! Z where .Z1 impls Y` for queries
like `T.Z1 as Y`, etc.
Any facet in the query self or the query target type may provide a
witness for the requirements of the impl lookup, so search through them
all.
We accept partially identified facet types in the query self, since
`Self` can be used inside a named constraint before it's fully
identified. But any use of `Self` being converted would put it in the
query self, not the query target, which would be some generic parameter
facet type that a type involving `Self` is being converted to.
TypeIterator is expanded to support this use case, by giving it the
ability to walk through FacetType's extend/impls constraints. We return
the facet values that we find in the iterator instead of a type id. And
we also include FacetValue instructions as an iterator step for clients
that want them, while also recursing through them.
Fixes mangling collisions when two thunks with the same name (eg, `Op`)
are created in the same context, which in turn would lead to LLVM
verifier failures and miscompiles.
To support this, add a new value store to track a little more
information about thunks beyond what's in the `Function`.
Avoid crashing on the fact that block scopes have no related InstId. So
we can't push the InstId of the current scope in the ImplIntroducer
node, as it can be None. Instead we have to find the parent InstId when
we're building the ImplDecl, because the ImplDecl has a node at the top
of the scope stack for the DeclNameStack.
Impls are allowed in sequential (non-declarative) scopes (functions,
blocks), but [redeclarations are not
allowed](https://github.com/carbon-language/carbon-lang/blob/db24042fe56d22275aa801696e2f8f5c4171e35b/proposals/p3763.md?plain=1#L279).
We now diagnose these redecls as invalid.
The key changes here are:
- Relocating and renaming it to align with `IdKind` (and relocating
`ToRaw` and `FromRaw` to follow it).
- Adding a `Dispatch` method that provides a generic overload-based API
for expressing per-ID-kind dispatch, and rewriting existing code to use
it.
Note in particular that using overloads instead of switch cases makes it
possible to generically handle all specializations of a templated ID
type, e.g. `SomeIdType<T>` for all `T`. We have no such templated ID
types yet, but I'm introducing one in a follow-up PR that needs this
capability.
An `impl` decl in an impl file can refer only to things defined in the
api file, without the orphan rule rejecting it. If they are in different
scopes (such as one being in a class and one not), then they are treated
as separate `impl` decls. But if they have the same type structure, then
they fully overlap which is an error unless they are in a match_first
block.
This catches the overlap when two `impl` decls are in the same library
but are split between the api and the impl file of the library.
Previously we only diagnosed if they were in the same _file_ but now we
diagnose if they are in the same _library_.
Insert the cleanup if and when the pending block is inserted, not
eagerly. And if the pending block is inserted by overwriting an existing
instruction, create a cleanup for that instruction rather than for the
instruction in the pending block that we are discarding.
Assisted-by: Gemini via Antigravity
A destructor is added to the C++ class definition in
`CarbonExternalASTSource::CompleteType`. The destructor calls a Carbon
function that calls the `Destroy` operator.
This lets us stop eliding it in textual semir tests with dump ranges.
Previously it would always get elided, even though it was part of the
range being dumped, and was referred to by other instructions in the
dump range.
Since each `.Self` is unique (can change its type if not its value) in a
facet type, having each one distinct by location also aids
understanding.
Also, when constructing the diff link, make sure we pick a commit that's
on the current PR's branch as the starting point. github wasn't able to
properly process the links we were creating before, if the last
dependency PR had commits that weren't on the current PR.
Fix a couple of tests that were broken by a prior change.
Assisted-by: Gemini via Antigravity
Move logic to merge class and function definitions onto Class and
Function, matching how we handle merging for EntityWithParamsBase.
Assisted-by: Gemini via Antigravity
A `where` expression nested inside a `T impls X` constraint makes
`.Self` ambiguous on the right-hand side of the `where` if `T` is
anything other than `.Self`. After the `where`, the value of a `.Self`
could be `T` or could be the value of `.Self` before the `impls`
constraint: the so-called top-level value of `.Self`.
Implicit use of `.Self` in designators is always allowed, and they are
bound (and replaced by a reference) to the inner-most possible value of
`.Self`. On the right-hand side of the nested `where` above, they have
the value `T as X`.
`.Self impls ...` is also always allowed, since it acts more as a
keyword here, and it always refers to the inner-most possible value of
`.Self`.
Any other explicit use of `.Self` is diagnosed when ambiguous, in any
kind of constraint. This is done in the handling of `WhereExpr` since it
has enough context to allow `.Self impls` (which is an explicit use)
while disallowing other explicit uses. And because it has non-canonical
instructions to work with, so it is able to diagnose errors with precise
locations.
Since `.Self` is no longer going to be marked with depth modifiers, the
eval of `WhereExpr` does not need an input facet value instruction
representing `.Self` to compare with, as they are now going to all be
equivalent. So revert it back to just looking for the `PeriodSelf` name
id, through a shared helper being introduced as `IsPeriodSelf`. And drop
the period self InstId from the `WhereExpr` instruction. This causes
most of the formatted SemIR changes.
Move helpers for working with and replacing `.Self` to their own file,
out of the `facet_type.h` header/cpp files. These are working with
`.Self` facet values more than facet types, though `.Self` is a name
that only exists inside the scope of a facet type.
Also preserve the error state rather than overriding it, though this
doesn't seem to make a difference in practice.
Assisted-by: Gemini via Antigravity
The `split(" ")` function will split two consecutive spaces apart,
giving an empty string in its output. So `dump context inst5` was
mis-parsed to have arguments `["context", "", "inst5"]`. If `split()` is
called with no arguments, it splits on whitespace but ignores
consecutive whitespace, so we correctly parse the args to be
`["context", "inst5"]`.
`dump context facet_type` was an error before since we expected that to
be followed with an id value. While `dump context facet_type 5` still
works, if there's no id value, try to use `facet_type` as a variable
name. This allows us to dump an inst id if it happens to be named
`inst`, etc, without having to use `--` to disambiguate.
The removed TODO warned that we'd end up with O(n^2) witness table
entries per specific. This isn't a problem for a single associated
function but will cause issues for larger custom witnesses.
This commit generates at most two `SpecificId`s with an inner `Self`:
one for associated constants and one for associated functions.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
When any field of a Carbon class is access from C++ for the first time,
all fields are exported as `clang::FieldDecl`s (this is necessary
because clang fields have an internal index that is initialized on first
use).
`ClangDeclStore` now provides bidirectional mapping. This allows looking
up a `ClangDeclId` by `InstId`, so when Carbon class fields are exported
they can be looked up that way.
This enables thunking to work when the function has `ref` parameters,
without jumping through hoops to add `ref` tags in the desugared
function body.
This also renames `is_operator_syntax` to `is_desugared`, which is more
general and more accurate.
See
[here](https://docs.google.com/document/d/1rWcueFwIfZox6GKVGxiUG4cBzjrZ6djXiIDGyJDtrE4/edit?tab=t.0)
for the design doc.
This also removes the default value of the `result_type_inst_id`
parameter of `HandleAction`, moves it before the action in the parameter
list, and documents it. This solves two problems:
- The default made it easy to forget, leading to unnecessary
`TypeOfInst` instructions.
- When it was present, putting it after the fairly "bulky" action
argument tended to make the callsite harder to read.
When importing a C++ function with an rvalue reference parameter, we
previously produced a Carbon value parameter. This would lead to the
toolchain believing it could pass the address of a non-expiring object
to the function, which would lead to a use-after-move.
Instead, we now map non-const rvalue reference parameters to Carbon
`var` parameters. This forces the object passed into C++ to be unique
and owned by the call. While that's not an exact match for C++ rvalue
reference parameters, given that it provides "always move" not
"conditionally move", it's the closest match we have at the moment.
When a namespace that was imported from C++ is indirectly imported, find
the corresponding namespace in the current C++ AST and return that
instead. This namespace may have completely different contents than the
one we found before; that's fine. The current file's view of a namespace
depends on what it imported.
Assisted-by: Gemini via Antigravity
Use A..HEAD, where A is the head commit of the most recent dependency
PR. This should list all commits that are in the current PR that are not
part of that dependency commit. Produce the "warning" message if that
diff will include any commits that are in any other dependency PR.
Assisted-by: Gemini via Antigravity
When an initializing expression is used to initialize a var parameter,
we need to create the storage earlier in SemIR than the initializing
expression. To do so, pass a pending block to initialization containing
the var storage.
Also stop using `temporary` for this purpose, since we treat temporaries
as potentially-constant and immutable, but `var` parameters can be
mutated by the callee. We should ideally introduce a new kind of
instruction for this purpose but for now we just use `var_storage`.
This gets us back to being mostly clang-tidy clean. This turns out to be
important for agentic coding agents, which otherwise sometimes try to
"fix" these false-positive lints.
Assisted-by: Gemini via Antigravity
Dana Jansens
Christopher Di BellaandRichard Smith
dependabot[bot]
Chandler Carruth
David Blaikie
Viktor
Lucile Rose Nihlen
Geoff Romer
Nicholas Bishop