carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-09-25 11:50:13 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity
Files
12ddfb9c7c1010fa209e41f86f0ddbc24301f929
carbon-lang/toolchain/check/testdata/interop/cpp/function/function.carbon
T
Ivana Ivanovska 12ddfb9c7c [Carbon/C++ interop] Add support for C++ overloaded functions (#5891) 
As proposed in [Carbon: C++ interop for overloaded functions and
function
templates](https://docs.google.com/document/d/1KUxumZtNe3mY3TsjW2s_ZADOlAaFlrtsLKHVILtqIaM/edit?tab=t.0),
Clang is used to perform the overload resolution using C++ rules, when
an overloaded C++ set is called from Carbon. Once a function is
selected, it's converted into a Carbon function and called using the
Carbon rules including argument conversions.

A single non-templated function is treated the same way as an overload
set and the same rules apply for its call.
Template functions are not supported yet.

Demo:

a) Non-templated function calls:

```c++
// --- overloads.h

auto foo(int a, short b) -> void;
auto foo(double a) -> void;
auto foo(int a) -> void;
```

```c++
// overloads.cpp

#include "overloads.h"
#include <cstdio>

auto foo(int a, short b) -> void {
  printf("hello from foo_int_short(%d, %d) \n", a, b);
}
auto foo(double a) -> void { printf("hello from foo_double(%f) \n", a); }
auto foo(int a) -> void { printf("hello from foo_int(%d) \n", a); }
```
```c++
library "Main";

import Cpp library "overloads.h";

fn Run() -> i32 {
  Cpp.foo(1.1 as f64);
  return 0;
}
```
```
$ clang -c overloads.cpp 
$ bazel-bin/toolchain/carbon compile main.carbon
$ bazel-bin/toolchain/carbon link overloads.o main.o --output=demo
$ ./demo
hello from foo_double(1.100000) 
```

b) Constructors:
```c++
// --- constructor_overloads.h
class C {
 public:
  C();
  C(int a, int b);
};
```

```c++
// constructor_overloads.cpp
#include "constructor_overloads.h"
#include <cstdio>

C::C() { printf("hello from C() \n"); }
C::C(int a, int b) { printf("hello from C(%d, %d) \n", a, b); }
```
```c++
library "Main";

import Cpp library "constructor_overloads.h";

fn Run() -> i32 {
  let c1: Cpp.C = Cpp.C.C();
  let c2: Cpp.C = Cpp.C.C(1, 2);
  return 0;
}
```

```
$ clang -c constructor_overloads.cpp 
$ bazel-bin/toolchain/carbon compile main.carbon
$ bazel-bin/toolchain/carbon link constructor_overloads.o main.o \--output=demo
$ ./demo
hello from C() 
hello from C(1, 2) 
```


Follow-ups:

- `Cpp.foo({})` - proper handling of struct literals as call args.
- Fix access for overloaded sets.
- Fix tests:
- Method calls: `error: missing object argument in method call
[MissingObjectInMethodCall]` in tests.
    - Fix `toolchain/check/testdata/interop/cpp/import.carbon` test.
    - Fix `enums` support.
    - Fix `str` -> `std::string_view` mapping.


Part of #5915
2025-09-15 12:29:49 +00:00

362 lines
16 KiB
Plaintext
Raw Blame History

// 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-FILE: toolchain/testing/testdata/min_prelude/primitives.carbon
//
// AUTOUPDATE
// TIP: To test this file alone, run:
// TIP: bazel test //toolchain/testing:file_test --test_arg=--file_tests=toolchain/check/testdata/interop/cpp/function/function.carbon
// TIP: To dump output, run:
// TIP: bazel run //toolchain/testing:file_test -- --dump_output --file_tests=toolchain/check/testdata/interop/cpp/function/function.carbon
// ============================================================================
// Global
// ============================================================================
// --- global.h
auto foo() -> void;
// --- import_global.carbon
library "[[@TEST_NAME]]";
import Cpp library "global.h";
fn MyF() {
//@dump-sem-ir-begin
Cpp.foo();
//@dump-sem-ir-end
}
// --- fail_import_global_use_different_name.carbon
library "[[@TEST_NAME]]";
import Cpp library "global.h";
fn MyF() {
// CHECK:STDERR: fail_import_global_use_different_name.carbon:[[@LINE+4]]:3: error: member name `bar` not found in `Cpp` [MemberNameNotFoundInInstScope]
// CHECK:STDERR: Cpp.bar();
// CHECK:STDERR: ^~~~~~~
// CHECK:STDERR:
Cpp.bar();
}
// ============================================================================
// Carbon keyword name
// ============================================================================
// --- special_name.h
auto base() -> void;
// --- fail_import_special_name_call_unescaped.carbon
library "[[@TEST_NAME]]";
import Cpp library "special_name.h";
fn MyF() {
// CHECK:STDERR: fail_import_special_name_call_unescaped.carbon:[[@LINE+4]]:3: error: member name `base` not found in `Cpp` [MemberNameNotFoundInInstScope]
// CHECK:STDERR: Cpp.base();
// CHECK:STDERR: ^~~~~~~~
// CHECK:STDERR:
Cpp.base();
}
// --- import_special_name_call_escaped.carbon
library "[[@TEST_NAME]]";
import Cpp library "special_name.h";
fn MyF() {
//@dump-sem-ir-begin
Cpp.r#base();
//@dump-sem-ir-end
}
// ============================================================================
// Overloaded
// ============================================================================
// --- overloaded.h
auto foo() -> void;
auto foo(int value) -> void;
// --- import_overloaded.carbon
library "[[@TEST_NAME]]";
import Cpp library "overloaded.h";
fn F() {
//@dump-sem-ir-begin
Cpp.foo();
//@dump-sem-ir-end
}
// ============================================================================
// Variadic arguments
// ============================================================================
// --- variadic.h
auto foo(int x, ...) -> void;
// --- fail_todo_import_variadic.carbon
library "[[@TEST_NAME]]";
import Cpp library "variadic.h";
fn F() {
//@dump-sem-ir-begin
// CHECK:STDERR: fail_todo_import_variadic.carbon:[[@LINE+7]]:3: error: semantics TODO: `Unsupported: Variadic function` [SemanticsTodo]
// CHECK:STDERR: Cpp.foo(8);
// CHECK:STDERR: ^~~~~~~~~~
// CHECK:STDERR: fail_todo_import_variadic.carbon:[[@LINE+4]]:3: note: in call to Cpp function here [InCallToCppFunction]
// CHECK:STDERR: Cpp.foo(8);
// CHECK:STDERR: ^~~~~~~~~~
// CHECK:STDERR:
Cpp.foo(8);
//@dump-sem-ir-end
}
// ============================================================================
// Static
// ============================================================================
// --- static.h
static auto foo() -> void;
// --- import_static.carbon
library "[[@TEST_NAME]]";
import Cpp library "static.h";
fn F() {
//@dump-sem-ir-begin
// TODO: We should eventually warn or error that `Cpp.foo` has internal
// linkage but is not defined.
Cpp.foo();
//@dump-sem-ir-end
}
// --- template_function.h
template<typename T>
auto foo(T a) -> void;
// --- fail_todo_import_template_function.carbon
library "[[@TEST_NAME]]";
import Cpp library "template_function.h";
fn F() {
//@dump-sem-ir-begin
// CHECK:STDERR: fail_todo_import_template_function.carbon:[[@LINE+7]]:3: error: template function is not supported [CppTemplateFunctionNotSupported]
// CHECK:STDERR: Cpp.foo(1 as i32);
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~
// CHECK:STDERR: fail_todo_import_template_function.carbon:[[@LINE+4]]:3: note: in call to Cpp function here [InCallToCppFunction]
// CHECK:STDERR: Cpp.foo(1 as i32);
// CHECK:STDERR: ^~~~~~~~~~~~~~~~~
// CHECK:STDERR:
Cpp.foo(1 as i32);
//@dump-sem-ir-end
}
// TODO: Add a test per unsupported param type. See https://github.com/carbon-language/carbon-lang/pull/5477/files/4321e21ed27d987fd71be182d292973fd9849df8#r2094655176
// TODO: Add a test per unsupported return type. See https://github.com/carbon-language/carbon-lang/pull/5477/files/4321e21ed27d987fd71be182d292973fd9849df8#r2094655176
// CHECK:STDOUT: --- import_global.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT: %empty_tuple.type: type = tuple_type () [concrete]
// CHECK:STDOUT: %.c5d: type = cpp_overload_set_type @foo [concrete]
// CHECK:STDOUT: %empty_struct: %.c5d = struct_value () [concrete]
// CHECK:STDOUT: %foo.type: type = fn_type @foo [concrete]
// CHECK:STDOUT: %foo: %foo.type = struct_value () [concrete]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT: %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
// CHECK:STDOUT: .foo = %.a21
// CHECK:STDOUT: import Cpp//...
// CHECK:STDOUT: }
// CHECK:STDOUT: %.a21: %.c5d = cpp_overload_set_value @foo [concrete = constants.%empty_struct]
// CHECK:STDOUT: %foo.decl: %foo.type = fn_decl @foo [concrete = constants.%foo] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @MyF() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT: %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
// CHECK:STDOUT: %foo.ref: %.c5d = name_ref foo, imports.%.a21 [concrete = constants.%empty_struct]
// CHECK:STDOUT: %foo.call: init %empty_tuple.type = call imports.%foo.decl()
// CHECK:STDOUT: <elided>
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- import_special_name_call_escaped.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT: %empty_tuple.type: type = tuple_type () [concrete]
// CHECK:STDOUT: %.f7d: type = cpp_overload_set_type @base [concrete]
// CHECK:STDOUT: %empty_struct: %.f7d = struct_value () [concrete]
// CHECK:STDOUT: %base.type: type = fn_type @base [concrete]
// CHECK:STDOUT: %base: %base.type = struct_value () [concrete]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT: %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
// CHECK:STDOUT: .r#base = %.6f0
// CHECK:STDOUT: import Cpp//...
// CHECK:STDOUT: }
// CHECK:STDOUT: %.6f0: %.f7d = cpp_overload_set_value @base [concrete = constants.%empty_struct]
// CHECK:STDOUT: %base.decl: %base.type = fn_decl @base [concrete = constants.%base] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @MyF() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT: %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
// CHECK:STDOUT: %base.ref: %.f7d = name_ref r#base, imports.%.6f0 [concrete = constants.%empty_struct]
// CHECK:STDOUT: %base.call: init %empty_tuple.type = call imports.%base.decl()
// CHECK:STDOUT: <elided>
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- import_overloaded.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT: %empty_tuple.type: type = tuple_type () [concrete]
// CHECK:STDOUT: %.c5d: type = cpp_overload_set_type @foo [concrete]
// CHECK:STDOUT: %empty_struct: %.c5d = struct_value () [concrete]
// CHECK:STDOUT: %foo.type: type = fn_type @foo [concrete]
// CHECK:STDOUT: %foo: %foo.type = struct_value () [concrete]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT: %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
// CHECK:STDOUT: .foo = %.a21
// CHECK:STDOUT: import Cpp//...
// CHECK:STDOUT: }
// CHECK:STDOUT: %.a21: %.c5d = cpp_overload_set_value @foo [concrete = constants.%empty_struct]
// CHECK:STDOUT: %foo.decl: %foo.type = fn_decl @foo [concrete = constants.%foo] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT: %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
// CHECK:STDOUT: %foo.ref: %.c5d = name_ref foo, imports.%.a21 [concrete = constants.%empty_struct]
// CHECK:STDOUT: %foo.call: init %empty_tuple.type = call imports.%foo.decl()
// CHECK:STDOUT: <elided>
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- fail_todo_import_variadic.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT: %.c5d: type = cpp_overload_set_type @<null name> [concrete]
// CHECK:STDOUT: %empty_struct: %.c5d = struct_value () [concrete]
// CHECK:STDOUT: %int_8: Core.IntLiteral = int_value 8 [concrete]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT: %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
// CHECK:STDOUT: .foo = %.a21
// CHECK:STDOUT: import Cpp//...
// CHECK:STDOUT: }
// CHECK:STDOUT: %.a21: %.c5d = cpp_overload_set_value @<null name> [concrete = constants.%empty_struct]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT: %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
// CHECK:STDOUT: %foo.ref: %.c5d = name_ref foo, imports.%.a21 [concrete = constants.%empty_struct]
// CHECK:STDOUT: %int_8: Core.IntLiteral = int_value 8 [concrete = constants.%int_8]
// CHECK:STDOUT: <elided>
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- import_static.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT: %empty_tuple.type: type = tuple_type () [concrete]
// CHECK:STDOUT: %.c5d: type = cpp_overload_set_type @foo [concrete]
// CHECK:STDOUT: %empty_struct: %.c5d = struct_value () [concrete]
// CHECK:STDOUT: %foo.type: type = fn_type @foo [concrete]
// CHECK:STDOUT: %foo: %foo.type = struct_value () [concrete]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT: %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
// CHECK:STDOUT: .foo = %.a21
// CHECK:STDOUT: import Cpp//...
// CHECK:STDOUT: }
// CHECK:STDOUT: %.a21: %.c5d = cpp_overload_set_value @foo [concrete = constants.%empty_struct]
// CHECK:STDOUT: %foo.decl: %foo.type = fn_decl @foo [concrete = constants.%foo] {} {}
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT: %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
// CHECK:STDOUT: %foo.ref: %.c5d = name_ref foo, imports.%.a21 [concrete = constants.%empty_struct]
// CHECK:STDOUT: %foo.call: init %empty_tuple.type = call imports.%foo.decl()
// CHECK:STDOUT: <elided>
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: --- fail_todo_import_template_function.carbon
// CHECK:STDOUT:
// CHECK:STDOUT: constants {
// CHECK:STDOUT: %.c5d: type = cpp_overload_set_type @As.Convert [concrete]
// CHECK:STDOUT: %empty_struct: %.c5d = struct_value () [concrete]
// CHECK:STDOUT: %int_1.5b8: Core.IntLiteral = int_value 1 [concrete]
// CHECK:STDOUT: %int_32: Core.IntLiteral = int_value 32 [concrete]
// CHECK:STDOUT: %i32: type = class_type @Int, @Int(%int_32) [concrete]
// CHECK:STDOUT: %As.type.047: type = facet_type <@As, @As(%i32)> [concrete]
// CHECK:STDOUT: %As.Convert.type.99b: type = fn_type @As.Convert, @As(%i32) [concrete]
// CHECK:STDOUT: %To: Core.IntLiteral = bind_symbolic_name To, 0 [symbolic]
// CHECK:STDOUT: %Core.IntLiteral.as.As.impl.Convert.type.676: type = fn_type @Core.IntLiteral.as.As.impl.Convert, @Core.IntLiteral.as.As.impl(%To) [symbolic]
// CHECK:STDOUT: %Core.IntLiteral.as.As.impl.Convert.086: %Core.IntLiteral.as.As.impl.Convert.type.676 = struct_value () [symbolic]
// CHECK:STDOUT: %As.impl_witness.a7b: <witness> = impl_witness imports.%As.impl_witness_table.3fe, @Core.IntLiteral.as.As.impl(%int_32) [concrete]
// CHECK:STDOUT: %Core.IntLiteral.as.As.impl.Convert.type.7bd: type = fn_type @Core.IntLiteral.as.As.impl.Convert, @Core.IntLiteral.as.As.impl(%int_32) [concrete]
// CHECK:STDOUT: %Core.IntLiteral.as.As.impl.Convert.11b: %Core.IntLiteral.as.As.impl.Convert.type.7bd = struct_value () [concrete]
// CHECK:STDOUT: %As.facet: %As.type.047 = facet_value Core.IntLiteral, (%As.impl_witness.a7b) [concrete]
// CHECK:STDOUT: %.323: type = fn_type_with_self_type %As.Convert.type.99b, %As.facet [concrete]
// CHECK:STDOUT: %Core.IntLiteral.as.As.impl.Convert.bound: <bound method> = bound_method %int_1.5b8, %Core.IntLiteral.as.As.impl.Convert.11b [concrete]
// CHECK:STDOUT: %Core.IntLiteral.as.As.impl.Convert.specific_fn: <specific function> = specific_function %Core.IntLiteral.as.As.impl.Convert.11b, @Core.IntLiteral.as.As.impl.Convert(%int_32) [concrete]
// CHECK:STDOUT: %bound_method: <bound method> = bound_method %int_1.5b8, %Core.IntLiteral.as.As.impl.Convert.specific_fn [concrete]
// CHECK:STDOUT: %int_1.5d2: %i32 = int_value 1 [concrete]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: imports {
// CHECK:STDOUT: %Cpp: <namespace> = namespace file.%Cpp.import_cpp, [concrete] {
// CHECK:STDOUT: .foo = %.a21
// CHECK:STDOUT: import Cpp//...
// CHECK:STDOUT: }
// CHECK:STDOUT: %.a21: %.c5d = cpp_overload_set_value @As.Convert [concrete = constants.%empty_struct]
// CHECK:STDOUT: %Core.import_ref.52c: @Core.IntLiteral.as.As.impl.%Core.IntLiteral.as.As.impl.Convert.type (%Core.IntLiteral.as.As.impl.Convert.type.676) = import_ref Core//prelude/parts/int, loc32_39, loaded [symbolic = @Core.IntLiteral.as.As.impl.%Core.IntLiteral.as.As.impl.Convert (constants.%Core.IntLiteral.as.As.impl.Convert.086)]
// CHECK:STDOUT: %As.impl_witness_table.3fe = impl_witness_table (%Core.import_ref.52c), @Core.IntLiteral.as.As.impl [concrete]
// CHECK:STDOUT: }
// CHECK:STDOUT:
// CHECK:STDOUT: fn @F() {
// CHECK:STDOUT: !entry:
// CHECK:STDOUT: %Cpp.ref: <namespace> = name_ref Cpp, imports.%Cpp [concrete = imports.%Cpp]
// CHECK:STDOUT: %foo.ref: %.c5d = name_ref foo, imports.%.a21 [concrete = constants.%empty_struct]
// CHECK:STDOUT: %int_1: Core.IntLiteral = int_value 1 [concrete = constants.%int_1.5b8]
// CHECK:STDOUT: %int_32: Core.IntLiteral = int_value 32 [concrete = constants.%int_32]
// CHECK:STDOUT: %i32: type = class_type @Int, @Int(constants.%int_32) [concrete = constants.%i32]
// CHECK:STDOUT: %impl.elem0: %.323 = impl_witness_access constants.%As.impl_witness.a7b, element0 [concrete = constants.%Core.IntLiteral.as.As.impl.Convert.11b]
// CHECK:STDOUT: %bound_method.loc15_13.1: <bound method> = bound_method %int_1, %impl.elem0 [concrete = constants.%Core.IntLiteral.as.As.impl.Convert.bound]
// CHECK:STDOUT: %specific_fn: <specific function> = specific_function %impl.elem0, @Core.IntLiteral.as.As.impl.Convert(constants.%int_32) [concrete = constants.%Core.IntLiteral.as.As.impl.Convert.specific_fn]
// CHECK:STDOUT: %bound_method.loc15_13.2: <bound method> = bound_method %int_1, %specific_fn [concrete = constants.%bound_method]
// CHECK:STDOUT: %Core.IntLiteral.as.As.impl.Convert.call: init %i32 = call %bound_method.loc15_13.2(%int_1) [concrete = constants.%int_1.5d2]
// CHECK:STDOUT: %.loc15_13.1: %i32 = value_of_initializer %Core.IntLiteral.as.As.impl.Convert.call [concrete = constants.%int_1.5d2]
// CHECK:STDOUT: %.loc15_13.2: %i32 = converted %int_1, %.loc15_13.1 [concrete = constants.%int_1.5d2]
// CHECK:STDOUT: <elided>
// CHECK:STDOUT: }
// CHECK:STDOUT:
Reference in New Issue View Git Blame Copy Permalink