If a type satisfies the requirements of a FacetType, then that type as a
value can be converted to a FacetValue, which binds the type value to
the FacetType.
For instance, if the class A implements an interface B, then
```
fn F(b:! B) {}
```
can be called with the type `A`
```
F(A);
```
This does not handle yet receiving non-type values matching a FacetType,
as that requires deducing the required FacetValue for the caller's
argument. Follow-up work will do this step.
---------
Co-authored-by: josh11b <15258583+josh11b@users.noreply.github.com>
Functions with positional parameters omit any implicit or explicit
parameter lists. This causes them to not have a pattern block, which
crashes if there is a return type that needs to add to the pattern
block.
Add a test covering this and handle it by having the ReturnTypeId
handler peek at the node stack and conditionally add the missing pattern
block. To do so it looks to see if the previous node is a
`IdentifierNameNotBeforeParams` which implies it was not expecting a
pattern (since there are no params) and thus the pattern block was not
added to the stack.
Note that lambdas also allow functions to omit an identifier, which will
need a pattern block on the stack for implicit parameters, explicit
parameters or a return type, without seeing any IdentifierName-like
parse nodes. To handle this, we will need to look for additional nodes
in the future and add the missing pattern block to the stack - possibly
for the FunctionInitializer, but the parse support needs to be created
for lambdas first.
AsCompatible changes a source instruction's type to a compatible type,
so it also needs its constant value to take on the compatible type.
Otherwise the type of the instruction and its constant value will
differ, which makes moving to the constant value into a lossy
transformation.
Part of #4868
Instead, produce a CARBON_FATAL error. Returning an Error constant from
the importer seems reasonable but turns out to not work well in
practice, because it violates the invariant that a constant value should
not have an error as an operand.
Also, don't produce an error constant for a valid ImportRefLoaded that
whose value is not constant; preserve the non-constant value instead.
For an expression such as `(Type as Interface).AssocFn()`, track the
`Self` type `Type` in the result of the member access so that it's
available when checking the function call.
This introduces a new kind of type, `ImplFunctionType`, that represents
the type of a function that is expected within an impl, modeled as the
type of the function within the interface plus a value to use as `Self`.
Calls to values of this type behave like calls to the underlying
function except that the `Self` parameter is pre-bound to the self type
from the facet.
In order to support this, fix an issue where the imported list of
generic bindings lost their association with their enclosing generic.
This adds a little complexity to `import_ref`, including a new recursive
cycle that I intend to address in a follow-up PR.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This switches most error printing to use diagnostics instead of direct
stream writes, even when not a specific file diagnostic. I'm allowing
empty filenames for this use-case.
This allows a little more specific testing to validate coverage of
output using the diagnostic coverage test. I'm adding a few tests to
cover things that weren't previously tested.
Separately, this also forces a little more standardization in format...
considering how changes like #4568 show effort being spent to _mirror_
diagnostic style, my thought is now to just use diagnostic code where
possible.
Note this also allows incrementally better testing of the language
server; I'm changing the crash fix from #4847 in favor of diagnostic
testing.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Based on [the lastest thinking on
#4672](https://github.com/carbon-language/carbon-lang/issues/4672#issuecomment-2606209281)
, require a full syntactic match for impl redeclaration, instead of
excluding the `where` restriction. This means no updates to the impl
witness on redeclaration, and no diagnostics that those updates are
consistent.
Not included in this PR, but will need to be done in the future:
* Support for assigning values to associated constants in the body of
the impl definition. This will require moving the checking that
non-function associated constants are set from the definition start to
definition end.
* Identify semantic redeclarations that are not syntactic matches to
give a failed redeclaration diagnostic. This should be done once we are
already identifying impl declarations with the same type structure in
order to require they be identified in an impl_priority/match_first
block.
* Merging of the functions in `check/impl.cpp` that are now always
called together.
Also add some test coverage of `where` parsing I developed in PR I've
now abandoned because of this new simplification of the impl
redeclaration semantics.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Add a full entity representation for associated constants, and build a
`Generic` object for them. This `Generic` is parameterized by the
enclosing `Self` type, allowing the use of `Self` within the type of the
associated constant to be supported.
When performing impl lookup for an associated constant, produce the type
with the provided self type substituted for its `Self` along with any
generic parameters of the interface.
Split the handling of associated constant declarations into two parts,
corresponding to the code before the `=`, and the code between the `=`
and `;` (if any). The former goes into the generic declaration region;
the latter into the generic definition region. This prepares us to
handle the default value for an associated constant, but for now we're
just storing the information and not actually using it.
Remove the entity type field from `assoc_entity_type`, because it's
almost unused and is an attractive nuisance -- it must necessarily be a
type in the generic scope of the associated constant rather than in the
scope of the instruction (because there is no `Self` anywhere else),
which means that it's hard to substitute into or derive meaning from.
See `toolchain/check/testdata/impl/assoc_const_self.carbon` for tests of
the new functionality; these used to cause the toolchain to crash.
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>
Add a Vtable typed inst with a type_id (of the type this vtable applies
to) and list of virtual function decls (or import refs to function
object constants).
This doesn't add lowering/emission of the vtable, or usage when
initializing objects of the type.
Some questions in case they're interesting to discuss:
* is it right/worth having the type_id in the vtable? (probably makes it
easier to emit - using the type to get the class name to figure out the
mangled name for the vtable) perhaps it should be a ClassId?
* I'm thinking the logic in CheckCompleteClassType could be the place we
handle diagnostics for mismatched keywords (virtual/abstract for a
function that's already virtual/abstract, maybe checking for non-virtual
functions with the same name in a base class, or derived class functions
without `impl`, etc) - but we could move some of that to the moment we
walk the function decl, and record our findings in the function decl
(record the base function it overrides, or the index of the vtable to
slot to use when building the vtable at the end of the class)
* the Vtable typed inst has `constant_kind = InstConstantKind::Always`
and `is_lowered = false`, I think I added that in to workaround/address
some failures in lowering. And seems correct for this intermediate step
- I'll add lowering in a follow-up patch. But the constant_kind - what
should this be? We can just say all vtables are of VtableType (in which
case the `Always` constant kind sounds right to me) or we could have
them introduce a type with each virtual function as a named member,
even?
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
When printing a Class, the complete_type_witness was printed last but
this gave a somewhat misleading representation as it appeared to be part
of the !members label. Move it above the label so that the label more
clearly refers to everything below it.
Rename `CheckIsAllowedRedecl` to `DiagnoseIfInvalidRedecl` to try to
better document behavior, and clean up comments.
This extends the no-merge-if-defined behavior to functions. It was
already the case for class/interface, and just added for impl, so if
anything functions were now inconsistent. I was kind of tempted to make
a helper for it, but I didn't think of a great structure/name to get
there: `DiagnoseRedef` isn't always called when it's a redefinition, for
example due to `extern` diagnostics, it's hard to combine.
Cleans up `is_defined` calls to rely more on `has_definition_started`,
removing some code paths that are unused since definitions aren't
merged.
Insert the poison at the same time we do the name lookup to avoid doing
two hash table lookups into each scope. This adds a bit of complication
because import logic now needs to cope with importing a name that is
already poisoned, but the complexity seems worthwhile to reduce the
number of name lookups performed.
This incidentally fixes a bug where we wouldn't poison any name scopes
if we found the name in an enclosing lexical scope, leading to one extra
diagnostic in existing tests.
Part of #4622
Fixes a crash, see the new regression test in
toolchain/check/testdata/impl/no_prelude/generic_redeclaration.carbon.
Stopping merging seems like the most straightforward way to prevent
references to generic regions with the incorrect block.
When declaring a class (or interface), we create a scope that covers the
entire class declaration. If the class was declared in a lexical scope,
we would declare the class name in the innermost scope, which was the
class's own scope instead of the enclosing lexical scope.
Fix this by instead adding the name to the lexical scope at the start of
the class declaration, not the lexical scope created to hold the class.
For now, we reject if the class name would have been shadowed by a name
that has already been declared within its scope, such as a generic
parameter, so we only ever need to modify the end of the list of lexical
lookup results for the class name.
This appears to be sufficient to make local declarations and definitions
of classes and interfaces work properly throughout check, though testing
is pretty minimal so far.
With this change, we now support impl of interfaces with non-function
associated constants.
Also:
* Make impl diagnostics use more consistent names
* Make some impl tests "no_prelude"
Still to do:
* Facet type resolution as a separate, reusable step
* Using the assigned values of associated constants (see
`fail_todo_use_assoc_const.carbon`)
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
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.
This change deliberately breaks away from the line/column ordering, and
instead focuses on a last byte offset corresponding to the final token
processed as part of producing the message. Where that's equal, this
maintains stable ordering in order to reflect the order that diagnostics
were produced.
The intent of this approach is that lex, parse, and check diagnostics
are interleaved based on where they are produced, but that
subexpressions still have diagnostics emitted prior to containing
expressions. In particular, the prior line/column sort essentially
sorted on the _start_ of where a diagnostic was associated, and this is
closer to sorting based on the _end_. As a consequence, something like
`F(1 2)` will have the error for `1 2` emitted _before_ a diagnostic for
`F(1 2)` not matching parameters, instead of _after_.
In check, we track the last handled node. This provides a
last_byte_offset _separate_ from where a diagnostic is associated. The
intent is that this creates an ordering of diagnostics which may be
associated with earlier code, to cause the diagnostics to be emitted
later. An example consequence of this is the change in ordering of
modifier diagnostics: we are diagnosing those from the same place, but
they have the same last_byte_offset, so we print them out in the order
produced.
I've added similar tracking to parse, but cannot identify any test which
is affected by it (note the separate commit, I thought about this late).
I'm not sure whether we have good out-of-order errors we could produce
for this.
A significant number of tests have reordered diagnostics as a
consequence of this change, so this change does not add further testing.
These don't fully work in check and beyond yet, because they're not
added into lexical lookup, but already mostly do the right thing.
Per #3407, disallow namespace declarations anywhere other than at file
scope for now.
We don't treat statements starting with a packaging introducer keyword
(`package`, `library`, `import`) as declarations because they're
sufficiently unlikely to occur that the error recovery doesn't seem
important, and this avoids needing to disambiguate `package.` at the
start of an expression.
Add a builtin `"int.convert"` supporting unchecked conversions between
different integer types. This performs a truncation, zero-extension, or
sign-extension, depending on the widths of the operands and the
signedness of the source type. Add explicit `As` support to the prelude.
No implicit conversions are supported yet as we don't have a way to
express the constraint that we can only implicitly convert to wider
types.
* Implement ignoring the difference between `Self as` and `as`, as well
as `where` clauses at the end of an `impl` declaration when checking
whether `impl` declarations match, from #3763.
* Allow impl declarations with different constraint ids to match, as
long as the facet type of the constraint has the same interface_id and
specific_id.
* Add some TODOs reflecting future facet type resolution.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
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>
When creating a tuple or struct type object/value, we will walk each of
the tuple's or struct's parts, respectively, and Convert() each of them.
This allows (T, T) to convert to (U, U) and so forth. It also performs
the conversion from value to initialization even for the same types,
such as converting from a value of (T, T) to an object of (T, T).
Classes need to define their own conversions but when the target and
source types are the same, there is no conversion of types taking place.
If the class adapts a tuple or struct then walk each of the tuple's or
struct's parts, respectively, and Convert() each of them in order to
initialize the parts of the target.
For copyable types, the conversion implies a copy in the initialization,
and for non-copyable types, an error is emitted.
This supports copying a class value to a class object when it is an
adapter of a tuple or struct.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Imported declarations that are contained within a generic, such as an
`impl forall...` would be given an abstract symbolic constant value
instead of a concrete generic value in some cases where the function was
used in an api file and impl file of the same library. This caused #4679
to fail using `ImplicitAs.Convert` transitively imported from the
prelude.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
* Change `InterfaceWitness` -> `ImplWitness`
* Include a `SpecificId` in the `ImplWitness`. This allows the
`InstBlock` it contains to have its own identity, allowing it to be
changed as the impl is processed. Evaluation only updates the specific.
* Create the `ImplWitness` at the start of the impl definition. In the
future, this will be populated with the values of non-function
associated constants. For now, it starts full of invalid instruction
ids.
* Implements the model suggested in #4672 .
Note that the non-SemIR testdata changes are to these file:
* `toolchain/check/testdata/impl/lookup/fail_todo_undefined_impl.carbon`
* `toolchain/check/testdata/struct/import.carbon`
* `toolchain/check/testdata/tuple/import.carbon`
The last two are due to an import of generics bug exposed by this PR,
which will be fixed in a follow-on.
---------
Co-authored-by: Josh L <josh11b@users.noreply.github.com>
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Fixes integer builtins to produce the correct values (and not
CHECK-fail) when used on integer literals. Also adds impls to the
prelude to use the new builtins to perform operations on integer
literals.
Perhaps most importantly, this allows directly initializing `i32` values
with negative numbers, as the negation operation on integer literals now
works.
For testing I've added tests for use of literals with one operator in
each class (addition, multiplication, ordering, bitwise, etc) for which
there are distinct rules or overflow behavior, rather than exhaustively
testing all the combinations. This is aimed at finding a good tradeoff
between maintainability of the tests and thorough test coverage.
Also fixes lowering of heterogeneous shifts and comparisons. These are
currently disabled when one of the operands is an integer literal, but
we may want to allow that when the integer literal operand has a known
constant value.
Add `EXTRA-ARGS:` support to file_test, to add arguments without
overriding the default arguments. Use `EXTRA-ARGS: --no-dump-sem-ir` to
turn off SemIR dumping and thus SemIR testing in the int builtin tests,
which validate correct behavior through diagnostics instead.
This doesn't get us any closer to supporting more targeted SemIR dumping
/ testing, but this seems to be a generally useful feature anyway. Most
existing
tests using `ARGS` have been switched over to using `EXTRA-ARGS`.
Requested in review of #4716.
Make `int.snegate` ignore the signedness of its operand and
unconditionally check for signed overflow like all the other `int.s*`
builtins do. Fix the prelude implementation of unary `-` for `Core.UInt`
to use `int.unegate` instead of `int.snegate`.
Fix the test for unsigned negate to actually test negating unsigned
integers, and add some tests that unary `-` also works.
Use a deque to maintain the set of instructions to be walked over. so
that the loop can append more instructions (with their related scope)
during iteration without requiring recursion.
---------
Co-authored-by: jonmeow <jperkins@google.com>
Dana Jansensandjosh11b
Richard Smith
Boaz Brickner
Geoff Romer
Calvin