When deducing arguments for generic parameters of an `impl`, the
deduction calls `Convert` on the input arguments. Often, the input
argument is a facet, and needs to be converted to a type via
FacetAccessType in order to produce a different facet. These
instructions end up being added to the semir, but only their constant
values are needed for the resulting specific returned from Deduce.
In the best case, these extra instructions are just noise in the semir,
or they just cause instruction names to get differentiated with larger
suffixes.
In the worst case, these extra instructions contain references to
instructions from a generic context, and leak them out of that generic
context and into another. In particular, when importing a
LookupImplWitness instruction, the re-evaluation of it can do deduce
(when the lookup is against a generic `impl`). The instructions created
in Deduce are not part of the import, and end up referring to imported
instructions from the local context, which leads to confusion in the
toolchain, and can crash.
The `import_self_specific.carbon` test demonstrates this. It causes the
`I.F` function to be imported from the `I` interface when building the
witness table for the `impl`. Doing so imports the specific of `C` which
includes a LookupImplWitness for `Self.Accoc` in `I`. The `Self` is a
BindSymbolicName with generic binding index 0, in `I`. When Convert
creates instructions in the generic `impl forall D`, however, they end
up referencing and including this BindSymbolicName into its eval block.
But the generic binding 0 in the `impl` is a very different thing (a
value of type `E`). This confusion leads to crashes.
This change makes dumping and debugging work again with InstIds that are
now tagged with the CheckIRId. The textual representation of an InstId
is changed from `irN.instM` back to `instM` but the `M` is now a hex
value with the tag as part of it, which is the same number that is
physically in the `InstId::index` field. This prevents any cases where
we would potentially print incorrect values for large InstIds.
We teach the `dump` command in lldb to parse hex values for InstId so
that we can paste these numbers back into the debugger.
The SymbolicBindingType refers to the type value that will be
substituted in for the BindSymbolicName, but holds onto the EntityNameId
from the BindSymbolicName instead of (or in addition to, for now) the
instruction.
The EntityNameId will be used to look in the ScopeStack to find the
witnesses either from the BindSymbolicName instruction, or other
instructions that specify `impls` constraints against the EntityName.
This will allow us to have the `T` in `I(T)` resolve to a `.Self`
reference in the type so that we get type equality with the binding's
type: `T:! I(.Self)`.
Locations are similarly fragile, because adding a comment changes them.
This has made me pause when making prelude changes in #6144, so dropping
them for those cases.
Instruction ids aren't actually that interesting outside debugging, and
can be churny when doing other structural changes. I've seen this in
particular when doing singleton changes, which bump every instruction
id.
Note there are still other ways fragility from locations can crop up.
This shouldn't be considered a complete fix, but hopefully a small
improvement.
Right now, the class destroy impl is incorrectly generated (first
discussed [in
Discord](https://discord.com/channels/655572317891461132/941071822756143115/1418614787449032826)).
If we want it to be correct, deferred definition logic would need to be
added, and the declaration would need to be moved inside the `class`
scope (along with whatever generic logic that needs).
This instead switches to a blanket impl, to avoid creating latent bugs
with generating the `impl` and function body in the wrong scope. This
approach uses the same blanket impl as aggregate destruction that was
added by #6098.
The intent here is to allow progress on other parts of `Destroy`. For
example, under this model the implementation of the function body could
be done as part of lowering the specific.
If a `BindSymbolicName` is converted to `type` and then to its exact
`FacetType`, we get a `FacetValue` wrapping the `BindSymbolicName` but
providing no different information: it has the same witnesses and
`FacetType` as the original `BindSymbolicName`. Yet it is a different
constant value, creating multiple canonical forms with the same meaning.
Now we make that `FacetValue` with the same `FacetType` as the
`BindSymbolicName` it wraps evaluate back to the `BindSymbolicName`,
making it the unique canonical form.
This makes the "shortcut" in convert for avoiding impl lookup when
converting from `FacetAccessType` to `FacetType` in this exact scenario
work the same as doing the full impl lookup.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
This is in support of a goal of changing the blanket `destroy` impl to
use (roughly):
```
private fn CanAggregateDestroy() -> type = "type.can_aggregate_destroy";
// Handles aggregate type destruction.
impl forall [AggregateDestroyT:! CanAggregateDestroy()] AggregateDestroyT as Destroy {
fn Op[addr self: Self*]() = "type.aggregate_destroy";
}
```
That isn't done here because there's still other issues that migrating
raises. What this *does* do is add the builtin functions, and in
particular, support to `FacetTypeInfo` to make `CanAggregateDestroy`
work.
The "special requirement" approach in `FacetTypeInfo` allows us to
support restricting a blanket impl under the current approach of impls.
Maybe we'll find a cleaner approach that can work in the future, but
this fits into the current model by propagating similar to other
requirements. I'm using an enum mask because we have a number of similar
things to add (e.g. copy, move) but I'm not sure we need a full vector.
A few alternatives considered were:
- Supporting syntax more like `where .Self impls
TypeCanAggregateDestroy(.Self, SupportedInterface,
UnsupportedInterface)`. I think it'd be a little cleaner, but requires
better compile-time evaluation in order to assess the type of the call.
Right now it's expected to be a `FacetType` too early to make this work,
and I was concerned about pouring too much more time down this route.
- Providing an actual interface, in particular doing name lookup back
into `Core.` for an interface. This would've added name lookup overhead,
and the question of whether an `impl` exists.
- Generating an interface. This avoids the name lookup, but would still
raise the question of whether an `impl` should also be generated. Work
I've previously done generating interfaces for class destruction also
feels complex to both write and understand (an unfortunate issue).
- Still modeling as an `ImplsConstraint`, for example by defining a
special `InterfaceId::CanAggregateDestroy = -2` similar to what we do on
other ids. I was hesitant because of how this expands the number of
modes of `InterfaceId`, and things for consuming code to watch out for,
for what feels like a relatively niche set of use-cases that are only
interface-like.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
When returning a value from a function whose return type has a by-copy
initializing representation, perform initialization like we do when the
return type has an in-place initializing representation. This makes our
SemIR representation more uniform, as the return expression will now
always be an initializing expression rather than a value expression, but
more importantly it means that attempts to return a non-copyable type by
value now fail, even if the type has a by-copy initializing
representation.
This catches a bunch of places where we were returning a value of an
unconstrained template parameter `T:! type`, which we were incorrectly
allowing because we didn't notice it was not copyable. Unfortunately
this then requires quite a few test updates.
Like #6034, this exposes a lowering issue where lowering crashes when
attempting to lower a specific copy operation for certain types; a
couple more tests are temporarily disabled here. An upcoming PR
dependent on this one will fix the issue and re-enable those tests.
Instead of hardcoding which types are copyable, add a `Core.Copy`
interface to perform copying. Move almost all the current copy support
to that interface. Some remaining pieces are still using builtin logic
after this PR:
* For tuples and structs, builtin logic is used to perform elementwise
copies. This also supports copying *adapters of* tuples and structs,
which seems like it may not be desirable, especially for non-extending
adapters. A `Copy` impl is provided for tuples of at most 2 elements, so
that `Core.Copy` constraints are satisfied, but we can't implement this
generally until we have variadics support, and don't yet have a
mechanism to generalize this to structs.
* For `enum` types imported from C++, builtin logic is used to perform a
copy. This is temporary until we have a mechanism to identify these
types from an impl in the prelude.
One lowering test in `toolchain/lower/testdata/class/generic.carbon` is
disabled for now, as it causes a crash in the lowering code due to an
ABI mismatch between the call signature in the lowered declaration of a
specific function and the call that is generated in the specific callee.
Fixing this is a little involved, and will be done in a separate PR.
---------
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>
Now that included files can specify `EXTRA-ARGS`, this uses that to
handle min_prelude files. Also moves `As`/`ImplicitAs` out to a shared
file, partly because we duplicate it a few times over, partly just to
show that it works.
Also removes the `min_prelude/` subdirectories because many of these
files were touched by autoupdate regardless. I noticed one conflict for
`impl_thunk.carbon`, so renaming that one to
`impl_thunk_min_prelude.carbon`.
`GetArgReplacements` I simply noticed was unused, so removing it.
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.
Previously we walked the global variables defined by the current file
and emitted an LLVM global variable definition for each of them. Now
instead, when emitting a constant reference to a global variable, we
emit an LLVM global variable declaration, and we then subsequently walk
the global variables defined by the current file and convert each of
them from a declaration to a definition.
In order to make import of names of global variables work, add support
for import of `var`, as well as support for importing `tuple_access` and
`tuple_pattern` in the case where the `var` has a tuple pattern in its
declaration. Also treat `bind_name`s that are reference bindings to
`var`s as having the same constant reference value as their `var` so
that we can properly import and lower them.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
- Track the `VarPattern` instruction on the `VarStorage` instruction so
that it's available for name mangling.
- Mangle global variables based on the first binding name within their
pattern.
- Give global variables external rather than internal linkage, except if
they have no bindings whatsoever in their pattern.
- To support lowering references to bindings nested within a global var,
such as for `var (x: i32, b: i32)`, add some basic initial support for
reference constant expressions. Treat a global `var` as a reference
constant, and treat an aggregate access into a reference constant as a
reference constant.
Don't import `ImplWitnessTable` into the `constants` block, because we
generally don't put `Unique` constants there. This matches the handling
of the other kinds of `Unique` constants. In order to keep the
instruction visible in formatted SemIR, add it to the `imports` block
instead.
Also fix a bug in the instruction formatter that resulted in
instructions in the `imports` block being omitted from the output if
they were only referenced by earlier instructions in the `imports` block
and by instructions in the `constants` block. This was already resulting
in some referenced instructions being omitted from the output, but also
occurred frequently for `impl_witness_table` instructions after this
change because it is common for the only reference to those instructions
to be from `impl_witness` instructions in the `constants` block.
Each of these types takes another type as an operand. Instead of storing
that other type as a `TypeId`, store it as an `InstId` so that we can
track how it was written, not only its canonical form.
The canonical constant values of these types continue to store the
canonical constant values of their operands, as normal.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
When converting to a facet there are three different failure modes:
1. You provided a non-type value. Only types can convert to facets. So
we tell you that we found a non-type value.
2. You provided a facet type (which has type TypeType) which does not
have witnesses for the the target facet's type. So we tell you that the
type `T` implements `X` but needs to implement `Y`.
2. You provided a (non-facet-type) concrete type (of type TypeType)
which does not implement the target facet's type (which is a FacetType).
So we tell you that we need the type to implement the FacetType but it
does not.
3. You provided a FacetAccessType (which is of type TypeType also, but
we special case this), whose underlying FacetType is not compatible with
the target facet's type. So we tell you that we need the type to
implement `X` but found a FacetAccessType `T` which implements `Y`.
Closes#5027
TODO to resolve whether it should conditionally say "object of"
depending on the category
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
High level, replacing `Id::Invalid` with `Id::None` and `Id::is_valid`
with `Id::has_value` for clarity, as discussed
[here](https://discord.com/channels/655572317891461132/655578254970716160/1331664574545395794).
The `IntId` refactoring is needed together with `AnyIdBase` because it's
also used with `ValueStore`.
Note, trying to be careful not to rewrite `EnumBase::InvalidIndex`, or
`is_valid` in general (e.g., `IdKind::is_valid`).
I've tried to sequence commits here:
1. Automatic replacements:
- `((?:Id|Index)(?: |::|\(|Base(?:\(|::)))Invalid((?:Index)?\W)` ->
`$1None$2`
- `<invalid>` -> `<none>`
- `InvalidNodeId` -> `NoneNodeId`
- `/\*invalid\*/` -> `/*none*/`
- `id((?:_|\(\))(?:\.|->))is_valid` -> `id$1has_value`
2. Manual edits:
- In `int.h` and `int_test.cpp`
- `IntT` has `is_value`, which I'm renaming to `is_embedded_value`.
- Manual edits to comments in this file.
- `AnyIdBase` and `IdBase`
- Declaration of `is_valid` -> `has_value`, `InvalidIndex` ->
`NoneIndex`.
- In `ids.h` and `ids.cpp`
- `is_valid` -> `has_value`
- `// An explicitly invalid ID.` -> `// An ID with no value.`; similar
for index
- Various math on `InvalidIndex` -> `NoneIndex`
- Various mentions of "valid" in comments
- In `value_store.h`, for `IdT::Invalid`, plus one comment
- In `impl.h` and `tokenized_buffer.h`, we had different initialization
of `::None` values (versus `ids.h` syntax) that I fixed manually.
- Spot checks to compile
- Particularly where `is_valid` replacements didn't catch spots due to
different naming.
3. Autoupdate tests
4. verbose.carbon (NOAUTOUPDATE)
5. Comment spot checks
Note there are probably other mentions of "Invalid" that should be swept
up, but I'd like to argue for merging and separating out remaining
cleanup since this is so sweeping (and likely to hit merge conflicts
from churn). We'll probably have lingering mentions of "invalid" for a
bit regardless, just because there are uses of "invalid" in non-Id APIs.
Changes the name of SemIR `import_ref`s to use the format
`<package>.<entity>`.
<table>
<tr><th>Before</th><th>After</th></tr>
<tr>
<td><code>%import_ref.05a: type</code></td>
<td><code>%Main.D: type</code></td>
</tr>
<tr>
<td><code>%import_ref.8f2: <witness></code></td>
<td><code>%Main.import_ref.8f2: <witness></code></td>
</tr>
</table>
* [Discord discussion in
#toolchain](https://discord.com/channels/655572317891461132/655578254970716160/1330253540999827577)
* Closes#4769
This removes some churn when adding new diagnostic cases to test files
(where previous to this change the newly added newline would cause the
previous diagnostic CHECKs to be updated including changes to the line
number because the CHECK for the blank line meant an extra line between
CHECK and source line).
A few alternatives discussed here:
https://discord.com/channels/655572317891461132/655578254970716160/1329573358475673723
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Include the index rather than the name in the fingerprint of a symbolic
binding. While both the index and the name contribute to the canonical
identity, using either one of them in the fingerprint is sufficient to
ensure that distinct entities get different fingerprints. Changing the
name of a symbolic binding should ideally not result in fingerprint
changes, so exclude the name from the fingerprint when we have an index.
Use the canonical type and constraint when fingerprinting an impl, so
that uses of names in `name_ref` instructions aren't considered, only
the entity the name resolves to, and different ways of spelling the same
type have the same fingerprint. This similarly allows compatible changes
to be made to impls without changing the fingerprint.
Exclude the declaration block when determining the fingerprint of a
declaration. The declaration block contains the declarations of
parameters of the declaration, which do affect whether two declarations
are identical, but not whether they denote the same entity, because it
would be invalid to have different declaration blocks for declarations
with the same name in the same scope. Therefore changes to the
declaration block are compatible, and it's useful for such changes to
not affect the fingerprint.
This is not easy to test in isolation with our current testing
machinery. However, a follow-on PR will change the name of a parameter
in the prelude, and with this in place, will not cause any changes to
occur elsewhere in the toolchain tests.
Use it in the instruction namer to make instruction names more stable
across unrelated changes to the toolchain or the prelude.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
This is a precondition for enabling the new pattern-matching subsystem
to support binding patterns that have `if` expressions in the type
position.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Instead of treating `Core.Int` as the toolchain's builtin `IntType`,
model it as a class that adapts the builtin type. This aligns us better
with the intended language model, gives an associated library for
`impl`s involving `Core.Int` to live within, and opens the door adding
member functions to `Core.Int` if we decide that is desirable.
Remarkably it also seems to make the formatted SemIR a little smaller,
because a call to a generic class generates less IR than a call to a
function.
For example, format the `ImplicitAs` interface as `Core.ImplicitAs`
rather than simply `ImplicitAs`.
When importing an entity in a namespace, also import a declaration of
the enclosing namespace if necessary so that we can determine its name.
The offsets were originally added to deal with churn from builtins in
the raw semir. In textual semir, we mostly see instruction IDs for
imports, and builtins have also settled down more.
On imports, where possible, use the `EntityNameId` for an import instead
of printing an instruction. Next, show the source location if we have a
node. Only show the instruction if there's no location.
This also exposes `Parse::Tree` and `TokenizedBuffer`, so that we can
pass a `SemIR::File` without the component parts. In particular this
allows us to get the `TokenizedBuffer` for import IRs without
substantial structural modifications. We may want to make these optional
for serialized `SemIR` later, but the nodes/tokens contain source
location, which we'd need for debug information -- so it's not clear how
much we can really make them optional without substantial information
loss.
Reduce arguments to just `File` in a few spots, as a result of the
accompanying `TokenizedBuffer` and `Parse::Tree`. Also updates style to
pass around `const File*` where the reference is maintained, instead of
`const File&`.
I was considering keeping a direct reference to the tree and tokens on
`Context`, but initially my thought was it wouldn't make much
difference. I can re-add those if desired, just as direct caching of the
`File` fields.
Goal is to reduce churn in names in test updates (by churning a lot of
them in this PR).
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
This introduces `calling_convention_param_ids`, a single block that
consolidates all the information that was being used by consumers of
`param_refs` and `implicit_param_refs`, in a form that's easier to
produce and typically easier to consume.
See also [this Discord
discussion](https://discord.com/channels/655572317891461132/655578254970716160/1300545448909738125)
regarding the decision to keep the return slot last in the SemIR calling
convention, even though it goes first in the LLVM calling convention.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
For the few remaining uses of the builtin `i32` type, manually build an
`IntType(Signed, 32)` value instead. These are:
- The return type of `Run`.
- The type that int literals in an `if` expression are converted into.
- The type of an array index expression.
We should consider converting those three cases away from `i32` over
time.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
- Do not include entities imported from files that we are not dumping.
- Do not include constants and import_refs that are not referenced by
something that we are including in the formatted output.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
This can lead to us trying and failing to print certain kinds of
constant value, but we can fix that in future changes.
Note that `StringifyType` should probably be substantially refactored.
For this change I'm trying to leave the overall structure relatively
intact, but hopefully this additional formatting support will help guide
future refactorings.
This does a few things:
* Replaces the single `TypeId` in the `FacetTypeInfo` struct with a
vector of `InterfaceId`, `SpecificId` pairs (sorted in id order)
representing the set of interface requirements of the facet type. This
will later be used to support facet types with multiple interface
requirements (as in `I & J` or `I where .Self impls J`).
* Replace `InterfaceType` instructions (used as the type of an
`InterfaceDecl` instruction) with `FacetType` instructions (introduced
in #4460) with a (newly introduced) `FacetTypeFromInterface()` function.
* Replace code that consumed `InterfaceType` values with code that
consumed `FaceType` values. I've generally left the assumption in the
code that it is dealing with a single interface, using the (newly
introduced) `FacetTypeInfo::TryAsSingleInterface`, and producing an
error otherwise. There isn't yet support for the `&` operator or `where
.Self impls`, so this is generally a good assumption for now, except you
can get a facet type with no associated interfaces from a `type
where`... expression. In some cases, the facet type value is pulled from
the evaluation of an `InterfaceDecl` instruction, where the single
interface assumption will hold permanently.
* Some related cleans up: nicer stringification and formatting of facet
types, suppression of some errors when there already was an error.
There is still a lot left to do, including:
* Type `type` should be a facet type with a reserved id, replacing the
built-in instruction.
* Code using `TryAsSingleInterface` should generally be upgraded to
handle more than (or less than) one interface. Name lookup should be
particularly exciting.
* Operator `&` should be defined on facet types, unioning their
interface and other requirements.
* Requirements from a `where` clause don't do anything yet.
* Impls and impl lookup need to resolve facet types, and do things like
determine if all the associated constants are given values.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Geoff Romer <gromer@google.com>
This is primarily to free up space in the BindingPattern insts, but as a
side effect it moves the link between BindingPattern and its BindName
out of the SemIR, and into a transient data structure in Context.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
When an instruction is created as part of an implicit call to an
interface member, we generated a bunch of constants for naming the
interface, finding the corresponding specific, accessing its member
function, and so on. This led to significant bloat in SemIR.
Instead, we now track whether an instruction is created implicitly in
its location, and where relevant, we use the constant value of the
instruction directly instead of storing a new `Inst`.
This doesn't reduce the amount of work we need to do, but does make the
representation in SemIR smaller and more readable.
This is in particular to avoid churn from changes such as #4370. I think
the import list can be helpful (particularly to understand what the
library is aware of), but it's a different trade-off for the prelude
package due to the implicit imports.
Dana Jansens
Jon Ross-Perkins
Calvin
David BlaikieandJon Ross-Perkins