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.
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.
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).
Richard Smith
Jon Ross-Perkins
josh11b