Note, I assume this doesn't affect all the TODOs (like for i32.carbon),
but does cut some things down (and requires updating some tests that
have prelude name conflicts, but I think they were intended to be
updated this way).
Change syntax for package declaration to put the `impl` keyword at the
start and remove the `api` keyword.
To support this, rearrange processing of package, library, and import
declarations to use the general modifier handling support in declaration
parsing rather than special-case logic.
There is an ambiguity in `impl package.Foo as Bar`, which we resolve by
treating `package` as an introducer after a modifier only if it's not
followed by `.`.
This was to track use of a declaration after import, prior to a
redeclaration. Per [discussion on
Discord](https://discord.com/channels/655572317891461132/1217182321933815820/1236016521059237962),
we likely don't need this check due to the change in behavior of
`extern`.
Rather than potentially getting one of many `extern` decls and depending
on it by accident, it is now planned to be _required_ to be imported,
and the library doing a non-`extern` decl must _know_ it's importing the
`extern` decl. The stricter requirement on the library means it now
seems more reasonable to use the `extern` decl.
So kind of rolling back #3831, though keeping `ImportIRInstId` (at least
for now) and keeping `Loaded`/`Unloaded` terminology (seems a nicer
fit).
This removes the builtin FunctionType, replacing it with a FunctionType
instruction. The constant for a FunctionDecl is now a StructValue with
type of FunctionType.
Note this means a function declaration produces _both_ a type, and a
value of the type. This has some consequences in terms of circularity,
and makes the importing of function declarations a little more complex.
It'll get particularly peculiar for imports because of the behavior of
the reference, but that's a known issue due to other things such as
`alias`. The impact will hopefully be contained to
ResolvePrevInstForMerge (and ImportRefs).
To note a small formatting change in diagnostics:
```
- // CHECK:STDERR: fail_member_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated <function> in Interface>` is not callable.
+ // CHECK:STDERR: fail_member_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated F in Interface>` is not callable.
- // CHECK:STDERR: fail_todo_facet_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated <function> in Interface>` is not callable.
+ // CHECK:STDERR: fail_todo_facet_lookup.carbon:[[@LINE+4]]:3: ERROR: Value of type `<associated F in Interface>` is not callable.
```
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
Change the names for emitted globals for constants with storage to
include both the name of the constant and the name of the use.
This causes the instructions to also be named in SemIR and in LLVM IR
constants.
We don't need it any more, and removing it simplifies a few things:
- One fewer predefined `File` and reserved ID.
- We now have simply `Builtin` instructions for builtins, instead of
having an `ImportRef` that indirectly references a `Builtin`.
- `ConstantId`s now always refer directly to a local constant, instead
of sometimes referring to an `ImportRef` for a constant in the builtins
IR.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
First steps towards using constant values in lowering.
For now, we reuse the regular instruction lowering to lower constants.
This mostly works, because we don't actually need an `llvm::Function` or
a current basic block when lowering a constant most of the time.
However, a special case is needed for lowering aggregate value constants
because they would otherwise create a stack alloca to store the
constant. Separate constant lowering code will be added in a future
change to clean this up.
When lowering a constant initializing expression, the result is a value
of the destination type, rather than code to initialize the destination,
so a separate copy step is required when finishing initialization from a
constant for a type that uses in-place initialization. Handling this
required extending `ReturnExpr` to track its destination location.
We currently often create non-constant `*_access` SemIR instructions
that are only used by constant `*_init` instructions. These cause
lowering to leave behind `getelementptr` instructions in the lowered IR
that are now unused. It should be possible to detect this case and avoid
producing these instructions, or to produce them lazily, but for now
we're just leaving them around for LLVM to clean up.
Use a level comparison during substitution to determine whether we're
substituting a particular binding. Evaluate symbolic bindings with the
same name and the same level to the same symbolic constant, for example
across redeclarations of a generic function.
In handle_class and handle_interface we assign TypeType, so is more
consistent. I think this had been missed because we haven't really been
using these declarations (historically, declarations didn't have a
type). It seems not to significantly affect output at present, although
I found this while trying to change merge behavior.
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?
Adds ImportIRId::ApiForImpl to reserve a specific slot for the `api`
import, so that the code can trivially determine whether an import is
from the same library. This is then used for merging function
declarations, because the rules for redeclarations in the same library
slightly differ as compared to other imports (note they're also not
identical to same-file rules).
The main thing this leaves from the recent #3762 is verifying that
entities forward declared in the `impl` file are also defined, but
that's not in-scope for merging; it's moreso post-checking validation.
Note, a lot of our `invalid <entity> ID` comments in ids.h were
incorrectly copy-pasted, so I've cut `<entity>`.
This doesn't significantly change logic, although I'm trying to add the
location to used state.
The issue I'm trying to address is how to identify a declaration as
"allowed to be redeclared". Consider:
```
library "a" api;
extern fn F();
```
```
library "b" api;
extern fn F();
```
```
library "c" api;
import library "a";
import library "b";
var x: auto = F();
fn F();
```
What currently happens is:
1. On import of "a", `F` becomes ImportRefUnused
2. On import of "b", `F` becomes ImportRefUsed in order to merge.
3. In "c", the call `F()` doesn't change the state.
4. In "c", the declaration `fn F();` needs some breadcrumb to understand
whether "F" has been referenced, as in step (3) here.
What I want to happen is:
1. On import of "a", `F` becomes ImportRefUnloaded
2. On import of "b", `F` becomes ImportRefLoaded in order to merge.
3. In "c", the call `F()` causes `F` to become ImportRefUsed
4. In "c", the declaration `fn F();` detects that `F` is already
ImportRefUsed, and can use the associated `used_id` for a diagnostic
about why redeclaring is invalid.
Note this PR isn't implementing (4). I'm focused on the refactoring to
add a new ImportRef state here.
In parse, form a list of methods that are defined inline, tracking where
they start, where they end, and which other inline methods are nested
within them.
In check, when we reach an inline method body, skip it and add it to a
worklist to be processed later. We also track when we reach the start
and end of a context in which inline method bodies are deferred, so that
we know when to replay the bodies.
When suspending a function definition to be processed later, the
`DeclNameStack` entry is moved to separate storage, including popping
the corresponding scopes from the scope stack and removing the
corresponding lexical names from lexical lookup. Later, when we return
to the function and parse its definition, the `DeclNameStack` entry is
restored. The same is done when we reach the end of a nested context
that can have inline methods, so that we can reenter the nested scope
before processing its members.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Fix a collection of issues that were preventing lowering for overloaded
operators from working.
Instead of creating `import_ref` instructions during name lookup in the
current block, whatever that might be, we now create them in the `file`
block always. This avoids inserting them into blocks that might not be
intended to contain them, such as functions, and avoids the IR generated
for a function depending on which names we happen to have looked up
first.
When importing a class, function, or interface, import its enclosing
scope ID. This is necessary to allow us to distinguish between functions
at interface scope, which shouldn't be lowered, and other functions, and
will also be used in future to provide qualified names for declarations
when printing types. In order to support this:
- Track the constant values of namespaces created during importing so
that we can find them when resolving an import ref. Use those constant
values to convert an enclosing scope ID from the imported IR into a
corresponding ID in the current IR.
- Change how we do two-pass import of classes and namespaces so that we
can do two-pass import even for non-defining declarations, so that we
can import the enclosing scope.
While working on the final point above, I reworked `TryResolveInst` to
return a flag indicating whether another pass is necessary instead of
implicitly encoding this in the `ConstantId`. This permits the handling
of classes to be simplified; now `import_ir_constant_values` is only
accessed in a single place.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
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>
Jon Ross-Perkins
Richard Smith
