llvm-project/clang/test/CodeGenCXX/cxx2b-static-call-operator.cpp
Tianlan Zhou ee01a2c399
[clang] static operators should evaluate object argument (reland) (#80108)
This re-applies 30155fc0 with a fix for clangd.

### Description

clang don't evaluate the object argument of `static operator()` and
`static operator[]` currently, for example:

```cpp
#include <iostream>

struct Foo {
    static int operator()(int x, int y) {
        std::cout << "Foo::operator()" << std::endl;
        return x + y;
    }
    static int operator[](int x, int y) {
        std::cout << "Foo::operator[]" << std::endl;
        return x + y;
    }
};
Foo getFoo() {
    std::cout << "getFoo()" << std::endl;
    return {};
}
int main() {
    std::cout << getFoo()(1, 2) << std::endl;
    std::cout << getFoo()[1, 2] << std::endl;
}
```

`getFoo()` is expected to be called, but clang don't call it currently
(17.0.6). This PR fixes this issue.

Fixes #67976, reland #68485.

### Walkthrough

- **clang/lib/Sema/SemaOverload.cpp**
- **`Sema::CreateOverloadedArraySubscriptExpr` &
`Sema::BuildCallToObjectOfClassType`**
Previously clang generate `CallExpr` for static operators, ignoring the
object argument. In this PR `CXXOperatorCallExpr` is generated for
static operators instead, with the object argument as the first
argument.
  - **`TryObjectArgumentInitialization`**
`const` / `volatile` objects are allowed for static methods, so that we
can call static operators on them.
- **clang/lib/CodeGen/CGExpr.cpp**
  - **`CodeGenFunction::EmitCall`**
CodeGen changes for `CXXOperatorCallExpr` with static operators: emit
and ignore the object argument first, then emit the operator call.
- **clang/lib/AST/ExprConstant.cpp**
  - **`‎ExprEvaluatorBase::handleCallExpr‎`**
Evaluation of static operators in constexpr also need some small changes
to work, so that the arguments won't be out of position.
- **clang/lib/Sema/SemaChecking.cpp**
  - **`Sema::CheckFunctionCall`**
Code for argument checking also need to be modify, or it will fail the
test `clang/test/SemaCXX/overloaded-operator-decl.cpp`.
- **clang-tools-extra/clangd/InlayHints.cpp**
  - **`InlayHintVisitor::VisitCallExpr`**
Now that the `CXXOperatorCallExpr` for static operators also have object
argument, we should also take care of this situation in clangd.

### Tests

- **Added:**
    - **clang/test/AST/ast-dump-static-operators.cpp**
      Verify the AST generated for static operators.
    - **clang/test/SemaCXX/cxx2b-static-operator.cpp**
Static operators should be able to be called on const / volatile
objects.
- **Modified:**
    - **clang/test/CodeGenCXX/cxx2b-static-call-operator.cpp**
    - **clang/test/CodeGenCXX/cxx2b-static-subscript-operator.cpp**
      Matching the new CodeGen.

### Documentation

- **clang/docs/ReleaseNotes.rst**
  Update release notes.

---------

Co-authored-by: Shafik Yaghmour <shafik@users.noreply.github.com>
Co-authored-by: cor3ntin <corentinjabot@gmail.com>
Co-authored-by: Aaron Ballman <aaron@aaronballman.com>
2024-01-31 15:27:06 +08:00

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3.8 KiB
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// RUN: %clang_cc1 -std=c++23 %s -emit-llvm -triple x86_64-linux -o - | FileCheck %s
// RUN: %clang_cc1 -std=c++23 %s -emit-llvm -triple x86_64-windows-msvc -o - | FileCheck %s
struct Functor {
static int operator()(int x, int y) {
return x + y;
}
};
auto GetALambda() {
return [](int x, int y) static {
return x + y;
};
}
void CallsTheLambda() {
GetALambda()(1, 2);
}
// CHECK: define {{.*}}CallsTheLambda{{.*}}
// CHECK-NEXT: entry:
// CHECK: {{.*}}call {{.*}}GetALambda{{.*}}()
// CHECK-NEXT: {{.*}} = call noundef i32 {{.*}}(i32 noundef 1, i32 noundef 2)
// CHECK-NEXT: ret void
// CHECK-NEXT: }
Functor GetAFunctor() {
return {};
}
void call_static_call_operator() {
Functor f;
f(101, 102);
f.operator()(201, 202);
Functor{}(301, 302);
Functor::operator()(401, 402);
GetAFunctor()(501, 502);
}
// CHECK: define {{.*}}call_static_call_operator{{.*}}
// CHECK-NEXT: entry:
// CHECK: {{.*}} = call noundef i32 {{.*}}Functor{{.*}}(i32 noundef 101, i32 noundef 102)
// CHECK-NEXT: {{.*}} = call noundef i32 {{.*}}Functor{{.*}}(i32 noundef 201, i32 noundef 202)
// CHECK-NEXT: {{.*}} = call noundef i32 {{.*}}Functor{{.*}}(i32 noundef 301, i32 noundef 302)
// CHECK-NEXT: {{.*}} = call noundef i32 {{.*}}Functor{{.*}}(i32 noundef 401, i32 noundef 402)
// CHECK: {{.*}}call {{.*}}GetAFunctor{{.*}}()
// CHECK-NEXT: {{.*}} = call noundef i32 {{.*}}Functor{{.*}}(i32 noundef 501, i32 noundef 502)
// CHECK-NEXT: ret void
// CHECK-NEXT: }
struct FunctorConsteval {
consteval static int operator()(int x, int y) {
return x + y;
}
};
struct FunctorConstexpr {
constexpr static int operator()(int x, int y) {
return x + y;
}
};
constexpr auto my_lambda = []() constexpr {
return 3;
};
void test_consteval_constexpr() {
int x = 0;
int y = FunctorConstexpr{}(x, 2);
constexpr int z1 = FunctorConsteval{}(2, 2);
constexpr int z2 = FunctorConstexpr{}(2, 2);
static_assert(z1 == 4);
static_assert(z2 == 4);
constexpr auto my_lambda = []() constexpr static {
return 3;
};
constexpr int (*f)(void) = my_lambda;
constexpr int k = f();
static_assert(k == 3);
}
template <class T>
struct DepFunctor {
static int operator()(T t) {
return int(t);
}
};
template<class T>
auto dep_lambda1() {
return [](T t) static -> int {
return t;
};
}
auto dep_lambda2() {
return [](auto t) static -> int {
return t;
};
}
void test_dep_functors() {
int x = DepFunctor<float>{}(1.0f);
int y = DepFunctor<bool>{}(true);
int a = dep_lambda1<float>()(1.0f);
int b = dep_lambda1<bool>()(true);
int h = dep_lambda2()(1.0f);
int i = dep_lambda2()(true);
}
// CHECK: define {{.*}}test_dep_functors{{.*}}
// CHECK-NEXT: entry:
// CHECK: {{.*}} = call noundef i32 {{.*}}DepFunctor{{.*}}(float noundef 1.000000e+00)
// CHECK: {{.*}} = call noundef i32 {{.*}}DepFunctor{{.*}}(i1 noundef zeroext true)
// CHECK: {{.*}}call {{.*}}dep_lambda1{{.*}}()
// CHECK: {{.*}} = call noundef i32 {{.*}}dep_lambda1{{.*}}(float noundef 1.000000e+00)
// CHECK: {{.*}}call {{.*}}dep_lambda1{{.*}}()
// CHECK: {{.*}} = call noundef i32 {{.*}}dep_lambda1{{.*}}(i1 noundef zeroext true)
// CHECK: {{.*}}call {{.*}}dep_lambda2{{.*}}()
// CHECK: {{.*}} = call noundef i32 {{.*}}dep_lambda2{{.*}}(float noundef 1.000000e+00)
// CHECK: {{.*}}call {{.*}}dep_lambda2{{.*}}()
// CHECK: {{.*}} = call noundef i32 {{.*}}dep_lambda2{{.*}}(i1 noundef zeroext true)
// CHECK: ret void
// CHECK-NEXT: }
struct __unique {
static constexpr auto operator()() { return 4; };
using P = int();
constexpr operator P*() { return operator(); }
};
__unique four{};
int test_four() {
// Checks that overload resolution works.
return four();
}