Files
carbon-lang/toolchain/lower/lower.cpp
T
Boaz Brickner 852d0191a9 Add support for importing C++ inline functions (#5427)
This requires:
* Making `FunctionDecl` mutable since generating code
(`HandleTopLevelDecl()`) requires a mutable declaration and since we
manually add `used` attribute to force code generation.
* Passing the file system to `Lower` since it's needed by Clang code
generation.
* Creating an internal Clang LLVM module and link it against the Carbon
LLVM module.

Demo:

```c++
// hello_world.h

extern int puts;
inline void hello_world() {
  ((int (*)(const char*))&puts)("hello world");
}
```

```carbon
// main.carbon

library "Main";

import Cpp library "hello_world.h";

fn Run() -> i32 {
  Cpp.hello_world();
  return 0;
}
```

```shell
$ bazel-bin/toolchain/carbon compile main.carbon
$ bazel-bin/toolchain/carbon link main.o --output=demo
$ ./demo
hello world
```

Based on https://github.com/carbon-language/carbon-lang/pull/5406.

Part of #5405.
2025-05-21 07:02:05 +00:00

29 lines
1.1 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
#include "toolchain/lower/lower.h"
#include <memory>
#include <optional>
#include "toolchain/lower/file_context.h"
namespace Carbon::Lower {
auto LowerToLLVM(llvm::LLVMContext& llvm_context,
llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem> fs,
std::optional<llvm::ArrayRef<Parse::GetTreeAndSubtreesFn>>
tree_and_subtrees_getters_for_debug_info,
llvm::StringRef module_name, const SemIR::File& sem_ir,
clang::ASTUnit* cpp_ast, const SemIR::InstNamer* inst_namer,
llvm::raw_ostream* vlog_stream)
-> std::unique_ptr<llvm::Module> {
FileContext context(llvm_context, std::move(fs),
tree_and_subtrees_getters_for_debug_info, module_name,
sem_ir, cpp_ast, inst_namer, vlog_stream);
return context.Run();
}
} // namespace Carbon::Lower