Fixes link failures when referencing a symbol involving a fingerprint
from a different package.
Previously we included the `Namespace`'s `import_id` as part of its
fingerprint, which caused local and imported namespaces to get different
fingerprints. We now store the `import_id` on the `NameScope` instead of
on the `Namespace` inst to avoid this problem.
Also, when we reach a package-level `NameScopeId`, consistently
fingerprint it as a (package name, library name) pair. Previously the
fingerprinting depended on whether it was imported or not, as an
imported `NameScopeId` had a parent scope (the current package). We need
to include the library name here so that private entities with the same
name in different libraries have different fingerprints.
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.
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 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`.
- A function with a return declaration always has exactly one
`ReturnSlotPattern`, representing the whole return declaration (whereas
previously that was omitted for value and reference returns).
- The `ReturnSlotPattern` always has a subpattern with the same form.
`OutParamPattern` already plays that role for initializing forms, and
`TuplePattern` will play that role for tuple forms. This change
introduces `ValueReturnPattern` and `RefReturnPattern` to represent
value and reference return forms.
- As before, the `ReturnSlotPattern` has a corresponding `ReturnSlot`
that represents the output that is initialized by a `return` statement.
Its structure parallels the structure of the `ReturnSlotPattern`, so we
need `ValueReturn` and `RefReturn` insts that correspond to
`ValueReturnPattern` and `RefReturnPattern`.
This is a step toward supporting generic return forms, where the
`ReturnSlotPattern`'s subpattern may be an action: this change ensures
that evaluating the action for a specific form produces the same SemIR
as if the form were concrete to begin with. More speculatively, this
should simplify the implementation of `return` statements with compound
return forms.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
This is only fixing the decision about *whether* to produce a witness.
Implementation of the witness is still a TODO, though where a body is
generated, it should also precisely reflect where one _needs_ to be
generated.
Note the tests:
- toolchain/lower/testdata/function/generic/import_core_witness.carbon
- toolchain/lower/testdata/function/generic/import_unused_def.carbon
These tests can probably be produced _without_ Core.Destroy, but I found
the essence of them while trying to build //examples with Core.Destroy
and a simpler minimization wasn't striking me.
Assisted-by: Google Antigravity with Gemini
---------
Co-authored-by: jonmeow <jperkins@google.com>
This enables some nice simplifications, and it's also a step toward a
broader restructuring of binding and parameter patterns.
Assisted-by: Gemini 3.1 Pro via Antigravity
This includes checking and lowering for concrete form literals. Support
for symbolic forms is future work.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This uses the `CARBON_KIND_ANY(AnyImportRef, auto import_ref):` syntax
that seemed to be favored [on
Discord](https://discord.com/channels/655572317891461132/655578254970716160/1478486848207720478).
This converted uses in the `sem_ir` directory to show it works
initially, then added `check` for full coverage plus validating the
`SemIR::` namespace discard.
Note in inst_namer.cpp, AnyBindingPattern includes FormBindingPattern
which wasn't previously handled.
I'm disabling clang-format because I think it formats with readability
issues, e.g.:
```
#define CARBON_KIND_ANY_EXPAND_AnyBinding(X, SEP) \
X(::Carbon::SemIR::AliasBinding) \
SEP X(::Carbon::SemIR::FormBinding) SEP X(::Carbon::SemIR::RefBinding) \
SEP X(::Carbon::SemIR::SymbolicBinding) \
SEP X(::Carbon::SemIR::ValueBinding)
```
Since `SEP` is typically a comma, it's also a nuisance to treat as an
argument to `X` (which could get better results).
Assisted-by: Google Antigravity with Gemini 3 Flash
This is a step toward removing the index from `InitForm`, so that equal
form values always have equal representations.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This is iterating on how `Destroy.Op` generates, to start adding body
capabilities. This changes the way the signature is created, and adds a
`CoreWitness` function kind so that mangling can prevent name
collisions. The result is that what _was_ `DestroyOp` is now
`Core.Destroy.Op` or, as can be seen in
toolchain/lower/testdata/interop/cpp/nullptr.carbon,
`_COp.<hash>:core.Destroy.Core` where `:core` is indicating that it's a
core witness (taking a note from `:thunk`).
Assisted-by: Google Antigravity with Gemini 3 Flash
Richard Smith
Dana Jansens
Geoff Romer
Jon Ross-Perkinsandjonmeow
Nicholas Bishop
