Members of `std::string_view` can't be accessed directly, because that
type maps into Carbon's `str` type (`Core.String`), so member access
doesn't find the C++ members. But they can be named via qualified name
lookup into a derived type. That crashed because we didn't expect the
non-Cpp type `Core.String` to be the parent of a Cpp-imported member.
Plus add some more test coverage for related cases (not involving `str`)
that already worked.
---------
Co-authored-by: Geoff Romer <gromer@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`.
Support an implicit conversion from `T*` to `Cpp.void*` and to `const
Cpp.void*`, and an `unsafe as` conversion in the opposite direction.
In order to support C++ calls taking and returning `void*` (which get
mapped to Carbon `Optional(Cpp.void*)`, also support conversions from
`Optional(T)` to `Optional(U)` if there's a conversion from `T` to `U`.
Fix a bug in `OptionalStorage` for `T*` where its `HasValue` was exactly
backwards.
This doesn't appear to be causing any problems, but seems worth avoiding
anyway.
---------
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
* When a C++ static data member is imported, evaluate its address to a
constant like we would for a namespace-scope variable.
* When an imported variable is used in a way that doesn't require its
type to be complete, emit the variable with an opaque type instead
of skipping it (and potentially crashing later).
Also add the code to support interop with simple assignment. This
doesn't yet work because we don't support overloaded simple assignment
in general yet.
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.
Remove the unnecessary two-phase creation of variables in C++ import. We
don't need to create a placeholder and overwrite it here, so stop doing
so.
Also, add the patterns to the imports table and don't create a
NameBindingDecl. The NameBindingDecl would never be used for anything.
This matches what we do when importing a Carbon variable, and improves
the formatted SemIR output.
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.
This unifies the default Clang arguments between the `clang` subcommand,
the `link` subcommand, and the `ClangInvocation` built for C++ interop.
This sets the stage to integrate either pre-built or on-demand runtimes
flags for both of these. However, this PR should have very little
practical difference. The biggest functional change is wrapping the
default arguments in flags to allow unused flags so that we can build a
collection of flags viable across compile and link.
This avoids us trying to produce a reference to the C++ destructor,
which Clang won't emit because it believes it's unnecessary. This
previously led to link errors.
Fixe #6502.
Pursuant to recent decisions on #6124, switch `Destroy` to use a
`CustomWitness` for its implementation. Right now this is manufacturing
no-op implementation functions on each lookup, which obviously isn't
ideal but is intended as a first pass. I'm mostly trying to find the
right balance between updating the approach to reflect new decisions,
while still breaking apart work in a way.
The `CoreInterface` logic is intended to build on `CoreIdentifier`
support. We have a number of additional interfaces that require
specialized logic, and that'll extend pretty far with C++ interop, so it
seemed easiest to have a generic function for it. That's what's
replacing the logic inside C++ interop that was doing string comparisons
(which could have already been moved to `CoreIdentifier`, I just missed
it in my first pass).
This adds `CustomWitness` support because the `Destroy` witnesses can be
imported cross-file. `CustomWitness` was previously only used for C++
types, which don't yet support import, which is why that wasn't
previously an issue. The addition of `query_specific_interface_id` is
similarly needed in order to get correct sorting of witness blocks when
imported.
This PR also removes builtin constraint logic (note this is in a
separate commit to help review; it's not a separate PR because it's
difficult to split apart without tests breaking). This had been made
generic with the expectation that destroy, copy, move, and conversions
would all need related support. Under the new decision, we are not going
to do blanket impls and will instead just manufacture a `CustomWitness`
for everything.
A lot of SemIR fingerprints change, but that's probably because the
addition of `Destroy` on core classes is yielding structural changes.
### Description
Currently, unqualified access to private members of the base class
compiles without error. This is due to `LookupUnqualifiedName` calling
`LookupQualifiedName` internally with `access_info` parameter set to
`std::nullopt`. This causes `IsAccessProhibited` to return `false`
immediately.
This PR fixes this issue.
### Changes
- Added a check where if the `access_info` is null and the current scope
we are looking is an extended scope (parent), initializes the
`access_info` with `highest_allowed_access` set to `Protected`.
Fixes#6239
Allow passing a C++ template as a template template argument to another
C++ template. Does not allow passing a Carbon generic as an argument.
Depends on #6474.
Instead of naming the root namespace `package` (because it's accessed by
the `package` keyword), change it to use the current package name. Note,
buried in the checksum changes,
`toolchain/check/testdata/package_expr/fail_not_found.carbon`:
```
- // CHECK:STDERR: fail_not_found.carbon:[[@LINE+4]]:16: error: member name `x` not found in `package` [MemberNameNotFoundInInstScope]
+ // CHECK:STDERR: fail_not_found.carbon:[[@LINE+4]]:16: error: member name `x` not found in `Main` [MemberNameNotFoundInInstScope]
```
for:
```
// CHECK:STDERR: var y: i32 = package.x;
// CHECK:STDERR: ^~~~~~~~~
```
I'll leave it to you if you prefer this; the alternative I see is to
just rename `IsCorePackage` to `IsImportedCorePackage`, and/or change it
to a helper that takes a `Context` and does the right thing with
`parse_tree` (which, I need for `Destroy`-related reasons and was my
default approach).
This is in anticipation of using the same construct for all
implementations of `Destroy`, as well as other similar use-cases with
language-defined interfaces.
Expose C++ class templates, variable templates, alias templates, and
concepts as callable values in Carbon, and map calls to them into
template-id formation, mirroring how Carbon generics behave. For now,
only type template parameters are supported; non-type and template
template parameters produce a TODO error.
Instead of parsing a complete C++ translation unit and then interacting
with the translation unit further after the fact, delay finishing the
translation unit until we finish the Carbon check phase. This fixes some
issues where we would produce duplicated or incorrect diagnostics at the
end of the C++ translation unit, particularly for unused declarations.
Now we're in control of how we parse the translation unit, also disable
parsing of C++20 modules if the syntax appears within `import Cpp
inline` code.
Keep the same clang parser alive throughout check, and use it instead of
building a new one when parsing macros. This resolves issues where the
translation unit scope was destroyed too early, resulting in unqualified
lookup within macros being unable to find global scope entities.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This separates the return type from the return pattern, and replaces the
return pattern with a block of return patterns. This is a step toward
support for `ref` returns (where there's no corresponding return
pattern) and compund-form returns (where there may be multiple return
patterns).
This is a prerequisite for support for interop with C++ template names.
No behavior change here, except that it sadly changes the fingerprinting
for a lot of tests.
Add a `CppWitness` and use it instead of using `ImplWitness` with an
`ImplId` and `SpecificId` of `None`. This witness can be substantially
simpler because we never need a `SpecificId`.
Similarly to the enums, these are for the moment only available when
referenced with a global scope “::”. Only integer constexpr are
available for now.
Part of #6303
Some of the macros tests were not printing the SemIR. Printing it can
help spot issues (as in PR #6440), so added that now for all passing
tests.
Part of #6303
If an impl lookup finds a final result, cache that and reuse it if we
perform the same lookup later.
In addition to reducing repeated work, this allows us to produce the
same result for repeated lookups that find a C++ operator. This isn't a
great solution to that problem, as it's not clear how to extend it to
behave correctly across import, but we don't have a solution for that
for C++ interop in general.
When performing impl lookup for `Core.Copy` for a C++ class type, look
for a copy constructor. If we find one, synthesize an impl witness that
calls the constructor.
This adds initial support for impl lookup to delegate to the C++ interop
logic for queries involving C++ types. For now, we don't implement the
rules from #6166 that compare a synthesized type structure for the C++
impl against the best Carbon type structure, but the framework for
building that support is established here.
Currently there is no caching of the lookup here, and we build unique
`ImplWitnessTable`s for each lookup, which leads to each impl lookup
producing a distinct facet value. This results in some errors in generic
contexts; this will be addressed in follow-up changes. This PR aims only
to support the non-generic case.
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
This extends #6364 to allow having:
* `Cpp.unsigned_long` as a distinct type when `unsigned long` is 32
bits.
* `Cpp.long_long` and `Cpp.unsigned_long_long` as distinct types when
`long` and `unsigned long` are 64 bits.
Similarly to #6364, we only support implicit conversions from the
matching literal type (`u32`, `i64` and `u64`).
See #6275 for rationale.
Part of #5263.
We already did this translation in the other direction, but we had no
mapping from `Optional(T)` to anything, so round-tripping a nullable
pointer from C++ through Carbon and back to C++ was previously rejected.
Enum constants in a macro replacement list are recognized only when
prefixed with “::”.
There is a `todo` test to make explicit that this still needs to be
fixed.
When prefixed with a global scope “::”, they are correctly found and
evaluated to a const.
Part of #6303
Don't attempt to defer overload resolution by creating a
`CppOverloadSet`; this was incorrect as we weren't saving the complete
clang::OverloadCandidateSet, resulting in template candidates not being
found. Moreover, saving the overload candidate set would be expensive,
as the representation is surprisingly large, and is unnecessary since
we're about to build a call.
In passing, improve the diagnostics for overload resolution failure to
use Clang's operator overload resolution messages rather than its call
overload resolution messages.
This fixes calls to templated operator overloads, which is the final
piece needed for us to successfully compile an iostream-based "Hello
world" program.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
I was trying to figure out the right way to get specifics to be added to
the work.
Technically, we could keep the pending_specific list; this is taking a
different approach of inserting inside the work stack, which will do
extra work moving entries, although typically that should be expected to
be small. One challenge of `pending_specifics` is that if we would need
to shift them to work after both `Done` (for immediate processing) and
`Retry` (for processing after the current instruction is later revisited
and done). That feels kind of awkward as additional tracking to do.
Also, the common case is probably that there's either 0 or 1 specifics
being added, so an additional vector may be significant overhead. That's
why I leaned more in this direction of just inserting them in the vector
of work.
For now, treat such classes as being final, since we can't correctly
derive from them.
This removes the last category of C++ class that we are entirely unable
to interop with, and is a prerequisite for interop with C++ iostreams
(which have a virtual base class).
This continues work to eliminate pending generics/specifics and get them
to be interleaved with instruction imports. I'm trying to use
`FinishGenericOrDone` here as a way to help ensure that code correctly
handles generics, where the simple alternative would be for each
`TryResolveTypedInst` call `SetGenericData` directly (but which might
make it easier to call the wrong `ResolveResult` function, and we do
need the `GenericId`s to be passed).
Ivana Ivanovska
Geoff RomerandCarbon Infra Bot
Richard SmithandGeoff Romer
Chandler Carruth
Jon Ross-Perkins
Özgür
Boaz Brickner