The purpose of the newline is to make it clearer where a given
diagnostic begins and ends, particularly as the first message of a
diagnostic may not be the error.
This is a trivial code change, but ripples edits through test files.
`Self` is modeled as a `bind_symbolic_name` with no corresponding value,
for now at least. In the future it might make sense to model it as a new
kind of instruction, or as a `bind_symbolic_name` whose value is a
`param`, but for now we just want it to introduce a symbolic constant.
In order to convert a value like the `Self` of an interface to a type, a
new instruction `facet_type_access` is introduced. This notionally
accesses the "type" field within a facet, converting it from a pair of
(type, witness) into just the type.
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.
When declaring an associated entity in an interface -- just associated
functions for now -- create an associated entity value and corresponding
type to represent a "slot in a witness table". Also track the list of
associated entities on the interface so that we will eventually be able
to check impls against them.
Associated entities are represented as the integer index of their slot
in a witness table.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
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.
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>
Jon Ross-Perkins
Richard Smith
josh11b