This is temporary: eventually per the design we should be forming
integer literals whose types reflect their values. But for now we should
ensure that values fit within their types.
This also fixes canonicalization of integer constants and hence of array
types, because we no longer have multiple different representations of
each `i32` value depending on the bit-width used for the literal.
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.
Support is added for all overloaded operator interfaces in the current
design apart from `Assign`, which is going to require some more work to
properly handle, given that primitive assignment currently has a special
implementation for quite a few builtin types.
As we don't have support for generics yet -- in particular, generic
interfaces -- there is no support for `*With` interfaces, but homogenous
interfaces such as `Add` are supported instead.
Factor out building of call expressions so that overloaded operators can
generate calls.
Switch a few places from using specific kinds of NodeId to a general
NodeId. Because overloaded operators and other things like implicit
conversions can result in member access and function calls, those
operations can't require a specific kind of NodeId.
Add import support for associated entities, and fix import support for
interfaces and symbolic bindings. We now import interfaces in two steps,
first importing a forward declaration then a definition, just like we do
for classes. For symbolic bindings, we ensure that each BindSymbolicName
is imported only once, because its ID is used as its symbolic identity.
This is necessary because we (only) support operator interfaces that are
defined in an imported Carbon package for now.
The entire contents of `check/operator.cpp` should probably be
rethought. In particular, doing a lot of name lookups on each operator
is likely to be bad for performance. But this gets us to the point where
overloaded operators are basically working, which seems like a good
place to iterate from.
For now, the tests that the individual operators map to the right
interfaces are mostly generated by a script, but that's just because I'm
expecting a fair bit of churn in how we define the prelude and the
`impl`s -- in particular, when we add support for `AddWith`, we'll need
to update all the tests. The plan is to remove the script once things
settle down.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
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.
`GlobalInit` block is now static block within a `SemIR` which will be
used to emit initialization instructions for variables in the `Package`
scope.
inst_block_stack now has additional methods to handle `GlobalInit` block
separately, this block can be popped without being finalized allowing to
accumulate between all instances of variables.
At the end of the `check` phase, if this block is not empty , the
function `__global_init` will be added with this block being inserted
into it.
This block is pushed to `inst_block_scope` at the end `BindName`,
allowing instruction to be emitted into it, then popped at the semicolon
(VariableDecl).
This significantly changes the `SemIR` output, that's why this commit
updates a lot of the test cases.
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.
In array indexing, move the check for an out-of-bounds index into the
constant evaluation logic, so that we will also benefit from it when
constant evaluating a compile-time function.
In tuple indexing, require a template constant index instead of an
integer literal.
Also, form `addr_of error` instead of `addr_of operand` when `operand`
is not a reference expression, so that we don't try to constant-evaluate
a meaningless expression.
Also, expect a constant for an array bound rather than specifically an
integer literal. This allows constant evaluation results to be more
easily tested by inspecting array bounds.
The constant value we associate with an initializing representation is
the object representation that the initializing expression will store to
its destination.
Also include the type in the profile of an instruction. This is now
necessary for array values, which are represented as tuple_value
instructions with array type, to avoid instructions with different types
being merged by constant canonicalization.
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.
Instructions created by splices during conversion are now evaluated, as
are instructions created in cases where we first create a placeholder
instruction and later replace it by a different instruction.
This also removes the ability to set a parse node and instruction
independently after creating an `InstId`, which could lead to them
accidentally not matching.
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 leaves a single state for each in the expr loop. I was trying to
think through ways to have per-token states, but they felt sort of
bulky.
Note this is more verbose: but I think the long-term is going to be that
when we start wanting to add handlers, we're going to need to switch to
different names based on the token found. As a consequence, the parse
state logic will end up diverging a little, and we'll just want to align
towards boilerplate handlers.
Short-term, this opens up a path for saying that each parse node
corresponds to precisely one token in success states, and separates out
what were becoming big handler functions in check.
Another incremental change to diagnostic formatting. I simply recurse
over all the tokens in the subtree of a parse node and construct a
`DiagnosticLocation` that covers all of the tokens.
I believe it's nicer for the user to be directed at the entire chunk of
source where the error is occurring rather then just pointing at the
bracketing/terminator tokens, but let me know if you all agree.
Most of the calls to `StringifyType` already passed `true` for
`in_type_context`. Checking the rest, I found that every one of them was
already sufficiently clear that they were printing a type, or could be
made so with a very small change to the diagnostic text.
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).
This is an incremental improvement on our diagnostic messages that
simply underlines an entire token if the token is larger than 1 char
(else it points to the single char with a caret like it used to).
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.
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.
Incomplete types may be nested within other types; for example, a tuple
type might have an incomplete type as an element. Handle such cases by
walking through nested incomplete types when completing a type. This is
done non-recursively in case a very complex type is formed.
Types are generally no longer completed at the point where they're
formed. Instead, we attempt to complete a type when it is used in a
context that requires a complete type, and diagnose if the type cannot
be completed at that point. This will be necessary for classes, which
can become complete after their first use, and helps tease out bugs
where a type completeness check is missing.
Using the computed value representation, fix lowering of struct and
tuple values to use the value representation rather than the object
representation. Fixes an issue found in the review of #3257.
This currently causes us to compute value representations of all types
as they are created, which generates substantially more SemIR to
represent types. We can get some of that back by deferring computation
of the value representation until the type is required to be complete,
but some of the additional cost here will persist with this approach.
I also considered making the computation of the value representation
type be something that lives entirely within the lowering phase, but I
think that's not the right approach in the longer term, because the
value representation will be semantically visible and relevant once we
start allowing it to be customized.
We should consider moving the nodes that exist to compute canonical
non-local types, including value representations, out into a separate
global block. That will clean up the SemIR representation substantially,
and make the SemIR produced for a function not depend on which types we
happen to have encountered beforehand. But that's not being done in this
PR.
---------
Co-authored-by: Chandler Carruth <chandlerc@gmail.com>
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.
Don't produce an error diagnostic if any of the information leading to
identifying that error is itself known to be affected by an
already-diagnosed error.
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.
Trust semantics to have put them in the right places.
Many parts of lowering still need to be updated to use the value
representation chosen at the semantics layer, but this is an incremental
step towards that.
Combine the initialization, implicit conversion, and value category
conversion functions into a single function.
This substantially reduces the duplication between these steps, and
ensures that we support the same set of conversions in all these
contexts. This also fixes some issues where we would not use the proper
value representation for tuples and structs after performing implicit
conversions.
This makes the difference between errors and lower-level diagnostics
visible to users, and aligns the toolchain's behavior with the
expectations in `driver_fuzzer.cpp`.
Fix a bug where we would perform the computation of the return location
in SemIR after we have already used it in some cases, leading to
assertion failures during lowering. Instead, accumulate a sequence of
instructions to compute the return location in a temporary block, and
overwrite the return slot with those instructions when we perform
initialization.
StubReference is replaced by a more general SpliceBlock node, that takes
a code block and a result value, executes the instructions in the block,
and produces the result. This is used in the uncommon case where more
than one instruction is required to compute the return slot, which can
happen if we need to first emit a temporary and then index into it, or
if we need to perform multiple levels of indexing before we reach an
entity to initialize.
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.
Richard Smith
Jon Ross-Perkins
Gıyaseddin Tanrıkulu
josh11b
Jacob Schneider
Geoff Romer