Rather than just adding `Self` to the lexical scope, add it to the
class's name scope so that it is visible in later lexical scopes for the
same class -- in particular, for out-of-line definitions of members.
Also switch some tests in `check/testdata/class` over to making
idiomatic use of `Self` both inside a class and out-of-line, now that it
works more consistently.
Note that this does not permit using `Class.Self`, but only because we
don't yet support keyword names after `.` at all. If that changed, one
could use `Class.Self` to redundantly refer to `Class`. Whether we allow
that is left to a future decision.
Previously we used the default inst block formatting, which writes out a
parenthesized list of references, which would always be 'unexpected
instref's because nothing else prints the instructions in the decl
block.
In addition, track the decl block for function declarations like we do
for other kinds of declaration. This means that the parameter
declarations for a function are now properly rendered into the formatted
IR. Note that this adds a lot of verbosity to `function_decl`, but it
does accurately reflect the IR, and we'll probably want this information
to be printed once we start supporting more complex generic function
declarations.
This removes almost all the 'unexpected instref's in our formatted
output. There are remaining cases when a declarative scope contains
multiple blocks, where we only track one of those blocks. That happens
when there is control flow within declarative scopes, and for error
recovery when a class or interface or similar is defined more than once.
As requested in #3730.
By adding a constant to ClassDecl/InterfaceDecl, we're able to remove
name reference special-casing. Use TryEvalInst on the Decl to generate
the Type. For ClassDecl, then use the generated constant for
self_type_id.
Building on #3636 which handles the general import case, add special
casing for namespaces. Namespaces can be combined cross-IR, so it's a
little more complex.
The implementation adds import_id to the Namespace instruction as a
reference to find the original using the normal structure. This is
achieved by moving the name_id to NameScope to free up space.
---
I considered a few alternatives...
I considered adding import_id to NameScope, but:
1. It's more consistent with things such as Function or Class that
provide name_id on the info object rather than the instruction.
2. I thought it more likely that there would be more NameScope cases
that might want a name_id rather than the import_id, since ImportRef
will typically be used.
I considered putting the import source (cross-ref IR id + inst id) on
the NameScope versus a separate ImportRef, which seems like the
strongest argument towards the NameScope approach because it removes an
instruction. That just felt inconsistent though, and the overhead of
instruction-per-imported-namespace should be low (theoretically few
namespaces should be used). Plus I feel a bit odd adding two
generally-unused ids to NameScope.
A specialized Namespace structure could also have been created to store
the import_id, but that would add an indirection to the NameScope.
Do not create runtime name bindings for `FieldDecl`s even though they're
declared with `:`, so that we can still constant-evaluate references to
fields.
Remove the type canonicalization mechanism and instead rely on constant
canonicalization to deduplicate types.
Rename the `Canonicalize*Type` functions to reflect that they're no
longer performing canonicalization. Switch code that creates types due
to semantic checking, rather than due to source syntax, to directly
create type constants through evaluation rather than creating an
instruction and evaluating it to produce a separate constant
representation.
The mapping from `const (const T)` that was previously performed by type
canonicalization is now implemented in expression evaluation instead.
The value `<error>` is now treated as a constant value, with a special
property that an instruction involving `<error>` that could possibly be
constant evaluates to `<error>`. This helps avoid producing follow-on
errors when an error occurs as a subexpression of an expression, such as
a type, that is intended to be constant.
Rather than producing multiple constants with the same value, fold all
instances of a given constant to the same constant instruction.
A future PR will use this to replace the current type canonicalization
system.
This is accomplished by tracking an extra bit on the ID we store in the
constant values table, and propagating that from subexpressions to the
enclosing expression. This extra bit is not yet computed correctly for
types; that will be addressed in later PRs.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
Form a side table with constant values for each instruction. Evaluation
is only supported for a few very simple kinds of instruction for now.
This is not observable outside of the SemIR output, because nothing
depends on expressions having a constant value phase yet.
Namespaces are copied, which means also adding their name to the
underlying instruction. It happened not to be done previously; the name
was only in name lookup.
Since the only import supported right now is the default import,
functionality is limited; in the future I'll need to deal with namespace
vs package conflicts.
Tests of namespace imports are under "namespace" -- I figured this would
be best for scaling as more instructions get support.
This also improves some debugging-related output that I was trying to
use while trying to build the support.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
This creates a namespace for `package` scope.
It looks like names of class_decls in namespaces lead to an unexpected
instref. This is already true, as best as I can tell. I'm not sure if
there's a preferred approach to address that, so I've left a TODO for
now.
This removes the filename from the file-scoped block, and places it
above to make it clear where the full SemIR begins (with multifile,
providing a barrier between).
Instead of ad-hoc conversion tracking on some kinds of nodes that
conversion creates, consolidate tracking into a single node kind. This
frees up an operand on `Init` instructions that can be used to store the
destination.
Add a `NameId` that is effectively just a wrapper around a `StringId`,
with
some additional predefined values for names that don't correspond to
strings, such as the name of `self` or the function's return slot.
If the initializing representation is the same as the value
representation, don't materialize a temporary and perform a value
binding. Instead, directly extract the value, using a new
`value_of_initializer` node.
This removes a lot of redundant `alloca`s from our generated LLVM IR.
Add support for member access into classes, for both non-instance
members and for fields.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Track the fields in a class, and generate a corresponding struct type as
the object representation for the class. For now, we always use a
pointer as the value representation for a class.
This replaces the use of `VarStorage` in this case.
Add an `UnboundFieldType` type as the type of a field, in cases where
it's referenced without an accompanying object.
Add a `BindName` node to describe the name binding performed for both
variables and fields so that we can handle them more uniformly.
Retain the `ClassDeclaration` node to represent a syntactic declaration
of a class (including possibly a declaration of a generic class), but
use a separate SemIR node to represent the class type itself. This
allows us to give the two separate treatment.
The `ClassDeclaration` is still entered into the name lookup table for
its enclosing scope, but when it is named in an expression, the class
type is produced instead. When the class declaration is named in a
declaration name, it can be used to define members of the class, but an
expression that resolves to the class type cannot be used to define
members of the class.
In order to distinguish these cases, use `Name` rather than
`NameExpression` for the left-hand side of a `QualifiedName` parse node.
This removes the only use of the `Expression` form of a declaration
name, so that is also removed.
In the future, `ClassType` will also be used to describe types such as
`Vector(T)`, for which there is no corresponding `ClassDeclaration`.
This includes being able to define a class that was previously
forward-declared, and being able to define a member function out-of-line
that was previously declared inside a class.
No support for fields or methods yet, and a class definition doesn't yet
cause the class to be treated as a complete type.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Richard Smith
Jon Ross-Perkins
josh11b