This is a step toward removing the index from `InitForm`, so that equal
form values always have equal representations.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
The key changes are:
- Function output parameters are now prefixed with `out`, and more
consistently formatted as named parameters.
- Function and inst output arguments are now written as part of the inst
form, rather than as one of the inst arguments.
As a drive-by fix, this also changes `Temporary::storage_id` from
`DestInstId` to `InstId`, because it doesn't represent an output
parameter of the `Temporary` inst itself.
See the review of
[#6532](https://github.com/carbon-language/carbon-lang/pull/6532) and
[this Discord
discussion](https://discord.com/channels/655572317891461132/999638000126394370/1458268977020141589)
for additional background.
Also clarify and enforce that `ConversionTarget::init_id` is used only
as storage for in-place initialization, and correspondingly rename it to
`storage_id`.
Not all functions have a return slot, and once we have composite forms,
functions will be able to have any number of return slots. Obtaining a
unique return slot for a function only makes sense in `returned var`
handling.
The main changes here are:
- Introducing `InitForm` and `RefForm` to represent initializing and
reference forms (the two return forms currently supported by the
parser).
- Introducing the `FormType` singleton inst to represent their type
(i.e. `Core.Form`).
- Emitting an inst representing a function's declared return form as
part of handling the function signature.
The return form inst is currently ignored. Subsequent PRs will expose it
in `SemIR::Function` and use it to determine the form of call
expressions.
Give TupleLiteral and StructLiteral a constant value, if their contents
have constant values. Their constant values are TupleValue and
StructValue respectively. This supports their ability to convert to a
constant type (or facet type).
This way when deduce finds a TupleLiteral as the argument to a
_symbolic_ facet type, it can also find a constant value to use for that
argument. This allows deduction to move onto step two, where it can
substitute into the symbolic parameter from previous deduced arguments,
and then perform the conversion from the TupleValue to the desired facet
type.
Allow `PerformBuiltinConversion()` to convert from a canonical
TupleValue or StructValue to `type` instead of only from literals. Then,
also support conversion from a symbolic binding of type TupleType or
StructType to `type`.
This resolves a TODO in `expr_info.cpp` by using the inst kind rather
than the bound value to track the binding's category.
Since we're churning all the `bind_name` insts in testdata anyway, I'm
also taking this opportunity to align the inst naming with the design's
terminology, by calling these insts "bindings" (this aspect of the PR is
dependent on #6231 resolving an ambiguity in that terminology). For
consistency we'll need to rename several other insts as well (see the
TODO on `RefBinding`); I'm deferring that to a separate PR to minimize
the review load, but I think those name changes are in-scope for this
review.
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.
This drops file_test runtime from about 3s to 2.5s on my machine, which
is now ~30% faster than before #5653 slowed things down by adding a lot
of stuff to the production prelude.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
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.
This could probably go further, but I'm just trying to get the ability
to run some significant tests without the prelude. This already requires
some migration of `i32` and `bool` to non-prelude-dependent types
(technically not at the moment, but I'm trying to stick with the
philosophical model of the prelude).
Note this undoes part of #3895 which had made all lex/parse tests depend
on the prelude -- I don't think that was a necessary change. Rather, it
seems better to isolate individual lex/parse tests from the prelude. I'd
been on the fence in that PR (it was fixing one of the issues that
contributed to wanting to not include the prelude), but now it feels
more consistent. The prelude could have a parse error and we shouldn't
break every parse test on that.
Factor out `SemIR::InstNamer` and also use it when lowering to LLVM IR.
Automatically name all instructions created with our `IRBuilder` based
on the name computed by the `InstNamer`, and likewise name basic blocks
using the label generated by the `InstNamer`.
Move some of the existing naming logic out from lower into `InstNamer`
so that it's also used in SemIR. In particular, we now name call
instructions after their callee, or after the builtin name for calls to
builtins.
Computing and adding these names isn't completely free. This instruction
naming is designed to be optional, so that we can turn it off for builds
where the LLVM IR will only be converted to assembly and won't be seen
by a human, but so far it's enabled unconditionally. We can tune that
later as needed.
Use the complete location of the `as` conversion rather than the
location of the first operand, so diagnostics referring to the result
point at the whole thing.
Move completeness check to the point where the function is defined or
first called. This means we also defer deciding whether the function has
a return slot until that point. Instead of storing a return slot per
function, store the location of the return storage, which may or may not
be used, and compute and store a separate flag saying whether to use it
at the point of first use or definition.
This is the final piece in supporting simple `Make` functions in classes
as a replacement for constructors.
- Adds an empty prelude.carbon file
- Imports that file in any non-Core package file
- Adds --disable-prelude-import to avoid that
- Adds --exclude-dump-file-prefix to be able to hide files from dumping
- Used to hide core files (we can't do this by package name due to lex
dumps, for example)
- Restructures some tests to not rely on `i32`, particularly `alias`
tests (which rely on a name ref) and tests with no prelude.
I'm adding the framework for switching i32 to calling Int32 in the
prelude, but I'm running into a separate error actually switching over.
So that *mostly* works, but isn't quite ready for prime time. However,
maybe the current state of this PR is still useful to review since it
does a lot of the infrastructure work and adds the %Core everywhere?
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).
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.
Track the callee expression in full, instead of only tracking the
callee's FunctionId. This results in the `name_reference` denoting the
function actually being used.
Lowering now propagates a `llvm::Function*` as the value associated with
expressions of type `<function>`.
We were not creating `NameReference` node for names produced by member
access into a namespace, such as the second name in
`Namespace.Function`, which caused lowering of calls to such names to
fail. This is now fixed, but the resulting `NameReference` node only
refers to the name and the lookup result, not to the `Namespace.`
qualifier. We'll need to decide how to fit a third operand into that
node (perhaps we can stop storing the `name_id`, since it can be derived
from the lookup result) but for now the qualifier is not tracked.
Bug found by fuzzing. Problem was untyped SemIR nodes had an invalid
type id, which was retrieved by `HandlePrefixOperator` and then passed
to `context.GetUnqualifiedType`, ultimately performing an invalid access
in `semantics_ir_->GetNode`.
We prefer to make a placeholder type for functions and namespaces to
remove the need for checking for the untyped case everywhere. Eventually
functions will have their own types, but this approach will be needed
for namespaces (and perhaps other non-first-class entities like unbound
methods and interface members) long term.
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Also add `name_reference_untyped` for references to non-first-class
names without types, which currently covers namespaces and functions.
This improves the fidelity of the SemIR representation, and fixes some
issues where we would use the wrong location for nodes and diagnostics
downstream of a name reference.
We're still missing a representation for dotted name expressions, such
as `Namespace.Function`, and we don't use the `untyped` node as an
operand of any other node yet.
The speculative insertion of StubReferences after elements in an
argument list turned out to not be necessary, because we decided we want
to insert per-argument initialization steps after all arguments are
evaluated, rather than interleaving them. The StubReferences we insert
are causing some minor code complexity, so remove them.
We still create StubReferences when performing patch-ups of
already-emitted code, but we no longer ever need to look through them
when determining whether an initializer was a literal or when evaluating
a type expression.
This implements initializing expression semantics for structs and
tuples, following #2006 and discussions since.
Tuple and (and analogously, struct) literals are treated as having a
mixed expression category that is later resolved based on how the
literal is used, as either a tuple initializer or a tuple value, at
which point we create a `TupleInit` or `TupleValue` that represents the
formation of the tuple initializer or tuple value from the tuple
literal.
There's quite a lot of TODOs here, and the SemIR representation is still
not quite right, but this seems like a good place to checkpoint some
incremental progress.
Building on #3214 and #3215, updates sem_ir yaml to be:
```
- filename: name
sem_ir: [ ... ]
```
Also, changes the textual format from `package { ... }` to `file
<filename> { ... }`. My thought on packages there is:
```
file "foo.carbon" {
package MyPackage
...
}
```
The reason for putting the file first is that it's easier if we put what
we're grouping on first, whereas the package is an "annotation" on the
file.
This better reflects the purpose of these semantics nodes, and prepares
for adding TupleValue and TupleInit nodes to represent forming values
and initializers from literals.
Continuing along with #3070. Note this is just a file rename, with BUILD
edits; every file previously in semantics/ should show as moved (except
maybe BUILDs, which split).