Files
carbon-lang/toolchain/check/import_cpp.h
T
Boaz Brickner 1d314c7c4d Import C++ constructors of class Type fn Type(...) -> Type (#5879)
Only supports classes with a single (non copy non move) constructor
(without default values), until overloading is supported.

Based on #5878.

C++ Interop Demo:

```c++
// hello_world.h

#include <cstdio>

class C {
 public:
  C(int x, int y) : x_(x), y_(y) {}

  int x() const { return x_;}
  int y() const { return y_;}

 private:
  int x_;
  int y_;
};

void hello_world(C* _Nonnull c);
```

```c++
// hello_world.cpp

#include "hello_world.h"

#include <cstdio>

void hello_world(C* _Nonnull c) {
  printf("C.x = %d. C.y = %d\n", c->x(), c->y());
}
```

```carbon
// main.carbon

library "Main";

import Cpp library "hello_world.h";

fn Run() -> i32 {
  var c : Cpp.C = Cpp.C.C(1, 2);
  Cpp.hello_world(&c);
  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
C.x = 1. C.y = 2
```

Part of #5880.
2025-08-06 12:02:38 +00:00

44 lines
2.0 KiB
C++

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#ifndef CARBON_TOOLCHAIN_CHECK_IMPORT_CPP_H_
#define CARBON_TOOLCHAIN_CHECK_IMPORT_CPP_H_
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/IntrusiveRefCntPtr.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/VirtualFileSystem.h"
#include "toolchain/check/context.h"
#include "toolchain/check/diagnostic_helpers.h"
#include "toolchain/diagnostics/diagnostic_emitter.h"
namespace Carbon::Check {
// Generates a C++ header that includes the imported cpp files, parses it,
// generates the AST from it and links `SemIR::File` to it. Report C++ errors
// and warnings. If successful, adds a `Cpp` namespace and returns the AST.
auto ImportCppFiles(Context& context,
llvm::ArrayRef<Parse::Tree::PackagingNames> imports,
llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> fs,
std::shared_ptr<clang::CompilerInvocation> invocation)
-> std::unique_ptr<clang::ASTUnit>;
// Looks up the given name in the Clang AST generated when importing C++ code
// and returns a lookup result. If using the injected class name (`X.X()`),
// imports the class constructor as a function named as the class.
auto ImportNameFromCpp(Context& context, SemIR::LocId loc_id,
SemIR::NameScopeId scope_id, SemIR::NameId name_id)
-> SemIR::ScopeLookupResult;
// Given a class declaration that was imported from C++, attempt to import a
// corresponding class definition. Returns true if nothing went wrong (whether
// or not a definition could be imported), false if a diagnostic was produced.
auto ImportCppClassDefinition(Context& context, SemIR::LocId loc_id,
SemIR::ClassId class_id,
SemIR::ClangDeclId clang_decl_id) -> bool;
} // namespace Carbon::Check
#endif // CARBON_TOOLCHAIN_CHECK_IMPORT_CPP_H_