`fn destroy` is being removed per decision on #6124. It seems like the
relevant decision will result in no more keyword-based function names,
so this is removing all related support.
This proposal renames the syntax used to mark an overriding definition
of a virtual method from `impl fn` to `override fn` to avoid ambiguity:
besides indicating an overriding virtual function, it can be parsed as
an "impl" declaration when the construct following "impl" begins with a
lambda introduced by "fn".
Closes#5711
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Also update `RequestVtableIfVirtual` to strip `impl` from functions in
classes without a base class - this avoids a duplicate diagnostic where
they're diagnosed as being in a class without a base class, then
diagnosed again because they don't have a matching function in a base
class.
This preserves the constant values of the arguments to the thunk, which
is important if the thunk requires conversion of an `IntLiteral` to some
other type. This should become unnecessary once we have form support,
but avoiding the indirection through a thunk function seems valuable
even once that support is in place.
To support this, track whether a function is a thunk on the Function
object, and if so, what the callee of the thunk is. This information is
also included in formatted SemIR when dumping the thunk.
Instead of using somewhat different approaches for defining in-line
methods at the end of the enclosing scope and defining thunks at the end
of the enclosing scope, we now use the same worklist for both.
This fixes a bug where we would crash when defining thunks if there
happens to be nothing else on the deferred definition worklist, leading
to our leaving the enclosing impl scope before we try to define the
pending thunk. That would only happen if the impl contains no in-line
member function bodies, so only if the impl has only a forward
declaration or a builtin declaration for every method. The latter
case happens (a lot) if we start using thunks in the prelude impls.
One complicating factor here is that this means the deferred definition
worklist moves from the layer containing `check/handle*` and
`check/check_unit.cpp` into the layer containing `check/context.cpp`.
Allowing that required moving a couple of other things that it depends
on -- notably `SuspendedFunction` and `HandleSuspendedFunction` --
around.
This reclaims a bit inside `LocId`. I'm hopeful we don't actually need
to store the token-only state.
Note I'm looking at this in the context of desugaring; I was thinking
about changing `ToImplicit` logic a little to push more towards
`GetCanonicalLocId`, and the "desugaring" TODO there. Removing
`ToTokenOnly` makes me feel a little more free to rename `ToImplicit`,
since it eliminates consistency as a question.
Instead of building the definition of a thunk immediately when we
generate the thunk declaration, wait until we reach the `}` of the
outermost class, interface, etc. -- at the same time when we would parse
the definition of the thunk if it were defined inline.
This fixes issues where we fail to define the thunk because it requires
an enclosing class to be complete, or its definition depends on
something declared later in the enclosing class.
Make the representation of a suspended function scope, and its
constituent suspended components, be move-only, and switch to passing it
around by rvalue reference instead of by value because it's expensive
both to move and especially to copy.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Instead of building an eval block as a separate pass at the end of a
generic, build the eval block incrementally.
The larger change here is that asking for the type or constant value of
an instruction now always returns an unattached type or constant value,
in order to preserve the behavior that we previously achieved by doing
the rewrite to attached types and constant values at the end of handling
the generic.
This also incidentally fixes some subtle issues where attached types and
constant values would leak out into check and cause it to get confused
about differences between attached and unattached values. Check should
no longer see attached values except where it explicitly asks for them.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
Remove calls to `InstStore::GetLocId()` to build a LocId from an InstId
now that they can be constructed directly from the InstId. Most uses of
LocId are just plumbing, so this does not affect them. However places
that want to look inside the LocId do not want to work with the InstId
form. In these places, introduce `InstStore::GetResolvedLocId()` which
converts a LocId (or an InstId as an optimization) into a LocId which is
not backed by an InstId. These locations can be printed (they have a
line and column when they are a NodeId), they can have flags added to
them (`ToImplicit`, `ToTokenOnly`), they can be converted to an
underlying ImportIRInstId, or they may be `None`.
`Dump()` is made to print a resolved location instead of printing the
InstId in the location, since (at least in my experience) the resolved
location is what is interesting in debugging, and this saves manual
`MakeInstId` steps in the debugger every time a location is of interest.
The LocId constructor from InstId is made `explicit` to add clarity to
function calls passing an `inst_id` now directly instead of calling
`context.insts().GetLocId(inst_id)`. To avoid needing to construct
`SemIR::LocId(...)` explicitly in all cases though, the diagnostics code
in Check uses `DiagnosticLocId` as its template parameter which accepts
InstId as well and does the construction of LocId from it.
Because LocId now requires an explicit construction from InstId, any
callers to `AddInst()` functions will have to explicitly convert to
LocId if they had an InstId, but not if they pass a NodeId. To make this
difference clear to callers, we `requires` that the input type can be
converted to LocId. This ensures that passing an InstId results in an
error at the callsite where the InstId is passed, instead of generating
a compiler error when trying to construct `LocIdAndInst` inside
`AddInst()`, which is less clear about what went wrong and doesn't seem
entirely intentional.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Not entirely sure what the SemIR representation for this should be - do
we put the bogus thing in the vtable, and just not lower it later? The
patch currently doesn't add the function to the SemIR vtable - which
then means you could find a virtual function that's not in the vtable,
which seems similarly confusing.
I guess we could make the function non-virtual?
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Right now, return_scope_stack is being used to determine whether logic
is in a function scope. However, we need to handle nested entities
inside function scopes. For example where this crashes right now:
```
base class C(B:! bool) {}
fn F() {
class B {
extend base: C(true or false);
}
}
```
This is doing a few things to make this kind of code not crash:
- Split `scope_stack().Push` into `PushForDeclName`, `PushForEntity`,
`PushForExpr`, and `PushForFunction` so that better decisions can be
made about behaviors.
- Hide `return_scope_stack` in the API, instead using interfaces to get
at the underlying data.
- Also using `PushForFunction` to update it similar to the other stacks
that `ScopeStack` manages.
- Add `IsInFunctionScope` as the best way to determine presence in
function scope.
- Remove `PeekIsLexicalScope` since destruction really wants function
scope information anyways.
- Clean up `destroy_id_stack` handling to be for function scopes rather
than lexical scopes.
- Return after related `context.TODO`s in a couple more spots, so that
code doesn't proceed to add control flow in spite of the lack of
support.
---------
Co-authored-by: Geoff Romer <gromer@google.com>
Provide builtins for compound assignments instead of defining them in
the prelude as a use of a binary operator and an assignment. This allows
us to lower compound assignment directly to LLVM operations instead of
producing a function call. In the short term this also allows us to
define a type-generic compound assignment in the prelude.
`FindIfOrNull` returns a pointer to the element in the range if it's
found, and nullptr otherwise. `FindIfOrNone` returns a copy of the
element in the range if it's found, and `T::None` (for a range of
elements of type `T`) otherwise. `Contains` returns a bool indicating
whether the element in the range is found.
These functions replace `llvm::find()` and `llvm::find_if()` when you
want a single answer back instead of an iterator. This avoids the need
to check against `end()`, allowing the return condition to be tested as
a standard bool.
We replace uses of `find()` and `find_if()` that did not require an
iterator with these new helpers.
Note that the return type of `FindIfOrNull` is a pointer since we can
not write `optional<T&>`, which must be tested for null. If the null
check is omitted, UB occurs and the resulting code may end up with an
incorrect pointer (https://crbug.com/40153300) into the range (or
elsewhere), rather than a null dereference. And this would be very
confusing to debug. Hopefully debug builds and sanitizers keep this from
being an issue we sink a bunch of time into debugging.
This fake generic was used for two reasons:
- The declaration name stack assumes that each declaration name is
processed within a generic scope. This is important if the name might
have generic parameters, which are always parsed even for declarations
that disallow them in check.
- Out-of-line redeclarations of generic entities produce instructions
with symbolic constant values in non-generic scopes.
The former case is addressed by pushing a generic each time we start a
declaration name, even if we will reject generic parameters later. The
latter case is worked around for now by not building a symbolic constant
type or value for instructions that appear outside of any generic, and
will be addressed more completely by #5310 and follow-ups.
We frequently want to operate on singletons. Per discussion, drop
`Singleton` to make the code shorter.
This started off as wanting to write `inst_id.is_error()`, but the
dependency relationship between ids.h and singleton_insts.h would
require some kind of delayed evaluation to allow the implementation to
remain in headers (which I suspect is helpful to have for inlining). I
could have added something like `IsErrorInst`, forward declared in ids.h
and defined in singleton_insts.h (which would always be included by
typed_insts.h), but the template approach felt like a decent balance
between (a) removing the boilerplate `::SingletonInstId`, (b)
understandability, (c) still visually mirroring if we immediately return
a singleton, and (d) flexibility for more than just `ErrorInst`. But TBH
I'd probably still have written `is_error()` if it didn't require
addressing the cross-header cycle.
Then I tried `SemIR::InstId::Is<SemIR::ErrorInst>`, which generally
worked with types but generated the complaint that it didn't shorten
*all* singleton uses. So pulling back on `::Is`, and instead just
dropping `Singleton`.
TypeInstId is an InstId whose constant value has a type of TypeType.
This includes:
- Type value instructions, the `ClassType` or `IntLiteralType`
instructions.
- Constraint value instructions, which are the `FacetType` and
`TypeType` instructions, each of which also have type TypeType.
TypeInstId encodes in the type system that it is safe to convert the
instruction's value to a TypeId, and CHECKs at construction that this
invariant is maintained.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Emitting definitions in check. This resolves the crash in lowering which
necessitated definitions be emitted.
Some of the test changes need further review.
What this does:
- Adds tracking where storage is allocated.
- Determines if that storage supports destruction and, if so, records
the `destroy` function for it.
- Calls any found `destroy` functions when going out-of-scope.
What this does not do:
- Precise scope tracking of temporaries. We currently don't define
temporary scopes, which would probably be the solution.
- Destruction for anything but a `class` with `fn destroy`, in an
implicit return. That excludes:
- Classes with members that need destruction, particularly in the
absence of `fn destroy`.
- Structs, tuples, and arrays.
- Explicit returns, break, continue, nested scopes.
Noting the exclusions in particular, I think those will need work to
support, but this should set the right framework.
The cleanup block concept stems from clang and trying to share code
across cleanups, from discussion with chandlerc. Note in this
implementation I try to find `destroy` functions early on: that's so
that, when destruction is present on multiple paths, particularly
non-shared paths, we only bind the `destroy` method once.
Implementation-wise, I'll note this adds a `has_cleanup` flag to
`TemporaryStorage` and `VarStorage`. There are several related options,
but this felt similar to other information we're trying to track on
instructions. My goal with this is to mitigate the chance of accidental
calls where the storage may not be tracked for destruction. Alternatives
I considered were to not add the flag (I was worried about heightened
risk of errors), or to just add a concept for the relevant `requires`
(which just felt inconsistent).
Cleanup logic ends up in control_flow in this change because I thought
it was a reasonably consistent place for the cleanup block concept and
its pretty direct control flow interactions.
When a generic function declaration was encountered for the second or
more time, we would FinishGenericRedecl() for the function decl, but
this just popped the generic region stack and moved on.
The issue with that is when the stack entry is gone, we lose the
symbolic constants from that declaration, and are unable to rewrite them
to point to the actual generic. This left us with a function declaration
with abstract symbolic values that were not useful, and in a function
call we use the declaration attached to the definition, which would be a
declaration with broken symbolic values. Then the function would be
uncallable since deduce would be unable to determine argument types
without the generic bindings.
This resolves the issue for functions, as well as ensuring the correct
generic id from a previous declaration is used for other generic entity
types that have redeclarations.
When a function declaration is qualified, such as defining a class
method outside the class body, we need only the function declaration to
contribute to its generic region stack. The code was collecting constant
values from all qualifier segments together incorrectly.
So when we PushNameQualifierScope(), we also drop the current generic
region stack and rewrite its constant values by calling
FinishGenericRedecl(), and open a new stack entry for the next part of
the qualified declaration.
If a generic declaration somehow has more dependent instruction than a
previous declaration, it would add new instructions to its eval block
with indices beyond the elements in the actual declaration eval block,
since we only store the block from the first declaration found. To avoid
this we plumb through that we are in a redeclaration, and terminate with
an ICE instead of adding new instructions to crash on later.
Fixes#5136.
Building on #5151 reducing `UncheckedLoc` use, further remove uses of
the `SemIR::LocIdAndInst` constructor where we typically have overloads
that don't need it. Add parallel convenience wrappers for placeholder
insts.
Also refactors `MergeReplacing`. I don't think it makes sense to add an
overload for `ReplaceLocIdAndInstBeforeConstantUse`, but we can still
reduce the `LocIdAndInst` construction there.
Move call_params_id from EntityBaseWithParams to FunctionFields.
No visible difference for Function. Since field call_params_id is
function specific fits better in FunctionFields.
According to approved syntax at
https://github.com/carbon-language/carbon-lang/blob/trunk/proposals/p3848.md#syntax-defined,
`fn F[]` without explicit parameters should be valid. This makes it
work, then adds some validation to prevent `class C[]` in check.
Note that for `fn`, positional parameters are a TODO -- but this allows
me to test validation in `fn destroy[]` which is rejected, not just a
TODO.
Trying to break apart the function on reasonable boundaries because it's
big. Changes behavior of class functions with virtual modifiers to
remove the modifier when diagnosing, which is more consistent with other
modifier diagnostics.
This makes inline and out-of-line functions produce the same type.
I was looking at this and wasn't sure if it was deliberate. It seems
desirable to reuse the type when possible, since it's probably cheaper
too.
- Explicitly document that `*Param` and `*ParamPattern` insts represent
`Call` parameters.
- Stop wrapping compile-time parameter patterns in `ValueParamPattern`
insts (because they aren't `Call` parameters).
- Document how `MatchContext::results_` relates to the `Call`
parameters, and be more consistent about when it's written to.
- Remove `RuntimeParamIndex::Unknown`: we no longer need to distinguish
"this `Param`'s runtime index is unknown" from "this `Param` isn't a
runtime param", because we no longer use `Param`s at all in the latter
case.
- Rename `RuntimeParamIndex` to `CallParamIndex`.
As a side effect of removing the `ValueParamPattern` insts, this fixes a
minor diagnostic bug where `NoteInitializingParam` didn't identify the
specific parameter that led to a deduction failure, because it expects
generic parameters to only be represented by `SymbolicBindingPattern`s,
but before this change they could be wrapped in `ValueParamPattern`s.
This tripped over a lowering crash when a member function with self was
declared-but-not-defined, so that's why some test cases were updated to
have (empty) function definitions.
I'll follow-up with/look into a fix for the
self-declared-but-not-defined cases separately.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
In order to have the name available for diagnostics, we now always set
`NameId` in `NameContext` and put `poisoning_loc_id` as part of the
union with `resolved_inst_id` instead (since we never need both).
This in particular uses free functions because it's likely to end up
more consistent with types (versus a wrapper object for InstStore).
Note, this is unlikely to have a performance impact, but if it does, we
can look into related approaches (and we've already discussed using
LTO).
Renames `PendingBlock::AddInst` to `PendingBlock::Add` because
`MakeElementAccessInst` expects the matching name to exist.
This creates a new check/type.h for most logic, and also moves some
functions to TypeStore in sem_ir/type.h. My approach for TypeStore is to
focus on moving the read-only functions there.
This ensures the data is available for more uses (specifically for
diagnosing virtual/abstract/impl functions on non-instance methods).
It still doesn't quite address the TODO to move the Self param search
all the way back to the param walk in all cases. To do that in the case
that still has a separate search loop, I think we'd have to change
`Check::NameComponent` to carry this information (as it carries the
implicit_param_patterns-id) - though there's comments in NameComponent
suggesting it shouldn't carry function-specific things like
`call_params_id` and `return_slot_pattern_id` - so I wasn't sure if it
was suitable to add more there, but I can - possibly in a follow-up
change.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Note this mirrors parse_tree().packaging_decl().is_impl, but I'm
preferring to keep the version that doesn't access the parse tree so
that we could change tree storage without hurting as much.
context.cpp is getting large, so I'm looking at a few ways to cut out
clusters of functions. This felt like a logical cluster of functions to
move to their own file.
Note this doesn't touch the implementation at all, beyond what's needed
to change from `Context` members to context args.
context.cpp is getting large, so I'm looking at a few ways to cut out
clusters of functions. This felt like a logical cluster of functions to
move to their own file.
Note I have two commits in this PR: one moving the functionality to a
new file, and one specifically changing TypeCompleter to use out-of-line
function implementations. This is to assist reviewability.
Functions with positional parameters omit any implicit or explicit
parameter lists. This causes them to not have a pattern block, which
crashes if there is a return type that needs to add to the pattern
block.
Add a test covering this and handle it by having the ReturnTypeId
handler peek at the node stack and conditionally add the missing pattern
block. To do so it looks to see if the previous node is a
`IdentifierNameNotBeforeParams` which implies it was not expecting a
pattern (since there are no params) and thus the pattern block was not
added to the stack.
Note that lambdas also allow functions to omit an identifier, which will
need a pattern block on the stack for implicit parameters, explicit
parameters or a return type, without seeing any IdentifierName-like
parse nodes. To handle this, we will need to look for additional nodes
in the future and add the missing pattern block to the stack - possibly
for the FunctionInitializer, but the parse support needs to be created
for lambdas first.
Jon Ross-Perkins
Elliott KaltandRichard Smith
David Blaikie
Geoff Romer
Boaz Brickner
Thomas Köppe
Alina Sbirlea
