mirror of
https://github.com/carbon-language/carbon-lang.git
synced 2026-09-24 21:10:12 +01:00
Boaz Brickner
870c5380a0
Triggered by calling a binary operator with LHS being an imported C++
class type.
Not supported (yet):
* Multiple overloads.
* Other operators.
C++ Interop Demo:
```c++
// hello_world.h
class C {
public:
C(int x) : x_(x) {}
auto x() const -> int { return x_; }
private:
int x_ = 0;
};
auto operator+ (C c1, C c2) -> C;
```
```c++
// hello_world.cpp
#include "hello_world.h"
#include <cstdio>
auto operator+ (C c1, C c2) -> C {
printf("Adding %d with %d\n", c1.x(), c2.x());
return C(c1.x() + c2.x());
}
```
```carbon
// main.carbon
library "Main";
import Cpp library "hello_world.h";
fn Run() -> i32 {
let c1 : Cpp.C = Cpp.C.C(7);
let c2 : Cpp.C = Cpp.C.C(8);
let c3 : Cpp.C = c1 + c2;
let c4 : Cpp.C = c3 + c2;
return 0;
}
```
```shell
$ clang -c hello_world.cpp
$ bazel-bin/toolchain/carbon compile main.carbon
$ bazel-bin/toolchain/carbon link hello_world.o main.o --output=demo
$ ./demo
Adding 7 with 8
Adding 15 with 8
```
Part of #5995.
62 lines
2.1 KiB
Plaintext
62 lines
2.1 KiB
Plaintext
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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// INCLUDE-FILE: toolchain/testing/testdata/min_prelude/full.carbon
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//
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// AUTOUPDATE
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// TIP: To test this file alone, run:
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// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/lower/testdata/interop/cpp/fail_extern_c.carbon
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// TIP: To dump output, run:
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// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/lower/testdata/interop/cpp/fail_extern_c.carbon
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// These tests were factored out of `extern_c.carbon` because we do not generate
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// LLVM IR if any test contains errors. They should be moved back once they can
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// successfully compile.
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// ============================================================================
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// extern "C" variable
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// ============================================================================
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// --- extern_c_variable.h
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extern "C" int foo;
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// --- fail_todo_import_extern_c_variable.carbon
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library "[[@TEST_NAME]]";
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// CHECK:STDERR: fail_todo_import_extern_c_variable.carbon:[[@LINE+4]]:10: in file included here [InCppInclude]
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// CHECK:STDERR: ./extern_c_variable.h:2:16: error: semantics TODO: `Unsupported: Declaration type Var` [SemanticsTodo]
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// CHECK:STDERR: extern "C" int foo;
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// CHECK:STDERR: ^
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import Cpp library "extern_c_variable.h";
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fn MyF() -> i32 {
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// CHECK:STDERR: fail_todo_import_extern_c_variable.carbon:[[@LINE+4]]:10: note: in `Cpp` name lookup for `foo` [InCppNameLookup]
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// CHECK:STDERR: return Cpp.foo;
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// CHECK:STDERR: ^~~~~~~
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// CHECK:STDERR:
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return Cpp.foo;
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}
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// ============================================================================
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// extern "C" function with C++ special name
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// ============================================================================
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// --- extern_c_with_special_name.h
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struct X {};
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extern "C" X operator+(X, X);
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// --- import_extern_c_with_special_name.carbon
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library "[[@TEST_NAME]]";
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import Cpp library "extern_c_with_special_name.h";
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fn MyF(a: Cpp.X, b: Cpp.X) -> Cpp.X {
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return a + b;
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}
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