`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.
If there's a unique "preferred" base class, then treat that as "the"
base class for Carbon's purposes. In particular:
* If there's exactly one polymorphic base class, that's our preferred
base class.
* If there's exactly one non-empty base class, that's our perferred base
class.
* (Degenerate case) If there's exactly one base class, that's our
preferred base class.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
This diagnoses instead of crashing in some cases:
* When one of the operands is an incomplete Carbon type.
* When one of the operands is a C++ class that can't be completed due to
lack of Carbon supported.
The new tests cover these cases.
Part of #5995.
This layer allows runtimes to be built on-demand but cached in a
consistent and re-usable location on the system. It handles careful
filesystem operations to ensure consistency even in the face of multiple
versions and build configurations.
This addresses a number of TODOs from the initial runtimes building
on-demand, and sets the stage to scale up to more runtimes.
This doesn't switch on-demand runtimes to be on by default, I wanted to
wait and make that change as a separate step.
---------
Co-authored-by: Geoff Romer <gromer@google.com>
This restores the original approach in #6046 as it appears
`--notool_deps` isn't sufficient in some situations. It still isn't
clear to me why it seemed to work initially, but I can easily reproduce
the issue now even with that flag.
I've tried to address the feedback in the original PR on the Python
code.
Don't ignore deleted constructors in overload resolution. If one is the
best match, we want an error rather than picking something else. Don't
crash if we find a constructor template or other weird thing; use
`getConstructorInfo` to map it into a constructor and skip it if it
isn't one, like Clang does.
I wasn't sure exactly in what way it was problematic, so I was a bit
vague in the justification (though justifications aren't generally
needed/provided here anyway - so I'm not sure it'd be net helpful to add
one anyway).
The general strategy here is to force use of a thunk when we want to use
default arguments, and have Clang generate uses of the default arguments
on its side of the thunk.
To support this, change the key type used in `clang_decls` from being
just a `Decl*` to being a pair of `Decl*` and number of parameters in
the case of function decls. Import distinct `SemIR::Function`s for each
number of parameters that's used, and corresponding distinct thunks.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
If a `BindSymbolicName` is converted to `type` and then to its exact
`FacetType`, we get a `FacetValue` wrapping the `BindSymbolicName` but
providing no different information: it has the same witnesses and
`FacetType` as the original `BindSymbolicName`. Yet it is a different
constant value, creating multiple canonical forms with the same meaning.
Now we make that `FacetValue` with the same `FacetType` as the
`BindSymbolicName` it wraps evaluate back to the `BindSymbolicName`,
making it the unique canonical form.
This makes the "shortcut" in convert for avoiding impl lookup when
converting from `FacetAccessType` to `FacetType` in this exact scenario
work the same as doing the full impl lookup.
---------
Co-authored-by: Richard Smith <richard@metafoo.co.uk>
`DeduceImplArguments()` works with the argument as a constant value, but
starts with the non-canonical `impl.self_id`. As these are both derived
from `impl.self_id` it just means an extra trip through the work loop to
try again with the canonical `impl.self_id` as the param. Save that work
and give canonical instructions for both param and arg in
`DeduceImplArguments()`.
Cleaned up `ImportNameFromCpp`, extracting smaller functions out of it.
Also added a documentation for `ClangLookup`. No changes in
functionality.
Part of #5915
Include notes listing the candidates and explaining why they didn't
work. Rather than duplicating the (substantial) logic for this, use the
Clang machinery to generate these diagnostics.
In order to support this, add a mechanism to map `SemIR::LocId`s to
`clang::SourceLocation`s. This works by creating source buffers in Clang
that refer into the Carbon source file so that `SourceLocation`s can
point into them.
---------
Co-authored-by: Jon Ross-Perkins <jperkins@google.com>
Multiple overloads for the same operator are now resolved using overload
resolution.
This change doesn't try to solve all issues with operator lookup.
Moved the operator lookup logic from `import` to `operators` and changed
it to take the args into account.
Use `Sema::LookupOverloadedBinOp()` (with ADL) when looking up operator
functions to create an overload set.
Verified all demos in #6017, #6020 and #6024 still work.
C++ Interop Demo:
```c++
// my_number.h
class MyNumber {
public:
explicit MyNumber(int value) : value_(value) {}
auto value() const -> int { return value_; }
private:
int value_;
};
class NotMyNumber {};
auto operator+(MyNumber lhs, MyNumber rhs) -> MyNumber;
auto operator+(NotMyNumber lhs, NotMyNumber rhs) -> NotMyNumber;
```
```c++
// my_number.cpp
#include "my_number.h"
auto operator+(MyNumber lhs, MyNumber rhs) -> MyNumber {
return MyNumber(lhs.value() + rhs.value());
}
auto operator+(NotMyNumber lhs, NotMyNumber /*rhs*/) -> NotMyNumber {
return lhs;
}
```
```carbon
// main.carbon
library "Main";
import Core library "io";
import Cpp library "my_number.h";
fn Run() -> i32 {
// Arithmetic
var num1: Cpp.MyNumber = Cpp.MyNumber.MyNumber(14);
var num2: Cpp.MyNumber = Cpp.MyNumber.MyNumber(5);
Core.Print(num1.value());
Core.Print(num2.value());
Core.Print((num1 + num2).value());
return 0;
}
```
**After this change:**
```shell
$ clang -c my_number.cpp
$ bazel-bin/toolchain/carbon compile main.carbon
$ bazel-bin/toolchain/carbon link my_number.o main.o --output=demo
$ ./demo
14
5
19
```
**Before this change**
```shell
$ bazel-bin/toolchain/carbon compile main.carbon
main.carbon:14:15: error: semantics TODO: `Unsupported: Lookup succeeded but couldn't find a single result; LookupResultKind: 3`
Core.Print((num1 + num2).value());
^~~~~~~~~~~
main.carbon:14:15: note: in `Cpp` operator `AddWith` lookup
Core.Print((num1 + num2).value());
^~~~~~~~~~~
```
Part of https://github.com/carbon-language/carbon-lang/issues/5995.
The main direction of this change is the edits to `destroy.carbon`
(matching in both prelude and min_prelude).
Previously there was a no-op blanket impl for `Destroy`, which hid all
missing implementations of `Destroy`. This does a few things:
- Sets up builtin aggregate destruction for struct and tuple types as
before, but also adds C++ class types and array types to the same
handling. (all as a TODO for actual implementation)
- Also maybe-unformed destruction, for now at least. (there's a chance I
may try a different approach on this, but the impl lookup wasn't working
as I'd hope in order to write it in code)
- Adds handlers for simple things that are easy to do in code: `type`,
`bool`, pointers. (because these are no-op destruction)
- Redirect `const T` destruction to `T` destruction.
This leaves as future issues:
- `partial T` destruction. (this can't be done similar to `const`
because it only works for non-`final` class types; I think `class`
definitions should just generate what's needed)
- Destruction of other prelude-provided types. (will probably come up as
we implement class destruction, that the adapted builtin type doesn't
implement `Destroy` -- but may end up special-casing that in a way that
moots it)
This moves the `&` operator from `facet_types.carbon` to
`convert.carbon` because more things need to handle type and now that
we're getting separate copy and destroy interfaces. It should be
low-cost (an interface and builtin) so hopefully this is the right
balance for complexity and re-use.
A few tests are also edited in order to focus them more on what they
intend to test, and avoid a `Destroy` dependency.
Only do the lookup when the class is complete.
Before this change we crash in `Sema::LookupQualifiedName()` on
`Declaration context must already be complete!`.
This is Itanium-specific for now (explicitly downcasting to the itanium
vtable handling code in Clang) - though it doesn't look like it'd be a
big stretch to either have conditional/two codepaths down Itanium and
MSVC in Carbon, or maybe add a virtual function in clang to avoid
needing to conditional+downcast in Carbon.
Here's a working example:
`dynamic_type.h`:
```
#ifndef TEST_H
#define TEST_H
struct A {
virtual auto virt0() -> int;
virtual auto virt1() -> int;
};
auto GetVal() -> A* _Nonnull;
#endif
```
`test.carbon`:
```
library "test";
import Cpp library "dynamic_type.h";
import Core library "io";
fn Run() {
var a: Cpp.A* = Cpp.GetVal();
Core.Print(a->virt0());
Core.Print(a->virt1());
}
```
`dynamic_type.cpp`:
```
#include "dynamic_type.h"
auto A::virt0() -> int {
return 0;
}
auto A::virt1() -> int {
return 1;
}
struct B: A {
auto virt0() -> int override {
return 7;
}
auto virt1() -> int override {
return 42;
}
};
auto GetVal() -> A* _Nonnull {
static B b;
return &b;
}
```
```
$ ./bazel-bin/toolchain/carbon compile test.carbon
$ clang++-tot -g dynamic_type.cpp test.o --output=a.out
$ ./a.out
7
42
```
(linking with `carbon link` failed because we aren't linking to the C++
runtime yet, it seems, so: `ld.lld: error: undefined symbol: vtable for
__cxxabiv1::__class_type_info`)
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
For now this works as follows:
* `T&&` is mapped to a by-value `param: T` parameter.
* `T&` is mapped to an `addr param: T*` parameter.
In either case, we will generate a thunk, which will internally pass the
parameter as a pointer.
Mark C++ functions as used when overload resolution selects them, and
trigger Clang's end-of-TU processing at the end of the Carbon
compilation to perform instantiation and other pending cleanup steps.
We already did the opposite direction; this enables use of `str` in
overload resolution.
Fixes#6062
---------
Co-authored-by: Dana Jansens <danakj@orodu.net>
Co-authored-by: Carbon Infra Bot <carbon-external-infra@google.com>
When a function template takes a parameter of deduced type, and we
deduce that type to a pointer type because we passed a Carbon pointer as
the argument, don't complain that the deduced type is not nullable. We
still know that it can't be null, because we deduced it from a
non-nullable type.
* Add support for template candidates by calling the suitable
`AddCandidate` function for them.
* Add support for overloading on `*this` qualifiers by calling
`AddMethodCandidate` when appropriate.
* Make mapping from Carbon arguments to Clang arguments a little more
faithful by mapping the Carbon expression category into the Clang value
kind.
This came up because `const T` needs destructor support... This change
makes `impl T as Destroy` and `impl const T as Destroy` distinct type
structures. Right now there's no impl lookup fallback (see
[#6068](https://github.com/carbon-language/carbon-lang/issues/6068)); so
when trying to destroy `const T`, there's no way to have an `impl` for
it to find.
In discussion, `MaybeUnformed` and `partial` have similar challenges, so
I'm covering them together.
In type_structure.h, I'm switching to an enum because it felt like an
easier way to be adding more types. I can switch back if preferred,
though then might take a closer look at the `operator==` because that's
kind of verbose.