llvm-project/clang/test/Modules/merge-constrained-friends.cpp
Chuanqi Xu da00c60dae
[C++20] [Modules] Introduce reduced BMI (#75894)
Close https://github.com/llvm/llvm-project/issues/71034

See

https://discourse.llvm.org/t/rfc-c-20-modules-introduce-thin-bmi-and-decls-hash/74755

This patch introduces reduced BMI, which doesn't contain the definitions
of functions and variables if its definitions won't contribute to the
ABI.

Testing is a big part of the patch. We want to make sure the reduced BMI
contains the same behavior with the existing and relatively stable
fatBMI. This is pretty helpful for further reduction.

The user interfaces part it left to following patches to ease the
reviewing.
2024-03-08 10:12:51 +08:00

69 lines
1.8 KiB
C++

// RUN: rm -rf %t
// RUN: mkdir -p %t
// RUN: split-file %s %t
//
// RUN: %clang_cc1 -std=c++23 %t/A.cppm -emit-module-interface -o %t/A.pcm
// RUN: %clang_cc1 -std=c++23 %t/Use.cpp -fprebuilt-module-path=%t -fsyntax-only -verify
// RUN: %clang_cc1 -std=c++23 %t/A.cppm -emit-reduced-module-interface -o %t/A.pcm
// RUN: %clang_cc1 -std=c++23 %t/Use.cpp -fprebuilt-module-path=%t -fsyntax-only -verify
//--- A.cppm
module;
export module A;
struct B {};
export template<int N> struct A : B {
friend constexpr const int *f(B) requires true {
static constexpr int result = N;
return &result;
}
template<int M>
friend constexpr const int *g(B) requires (M >= 0) && (N >= 0) {
static constexpr int result = M * 10 + N;
return &result;
}
};
export inline A<1> a1;
export inline A<2> a2;
export inline A<3> a3;
static_assert(f(a1) != f(a2) && f(a2) != f(a3));
static_assert(g<1>(a1) != g<1>(a2) && g<1>(a2) != g<1>(a3));
static_assert(*f(a1) == 1);
static_assert(*f(a2) == 2);
static_assert(*f(a3) == 3);
static_assert(*g<4>(a1) == 41);
static_assert(*g<5>(a2) == 52);
static_assert(*g<6>(a3) == 63);
//--- Use.cpp
// expected-no-diagnostics
import A;
// Try some instantiations we tried before and some we didn't.
static_assert(f(a1) != f(a2) && f(a2) != f(a3));
static_assert(g<1>(a1) != g<1>(a2) && g<1>(a2) != g<1>(a3));
static_assert(g<2>(a1) != g<2>(a2) && g<2>(a2) != g<2>(a3));
A<4> a4;
static_assert(f(a1) != f(a4) && f(a2) != f(a4) && f(a3) != f(a4));
static_assert(g<3>(a1) != g<3>(a4));
static_assert(*f(a1) == 1);
static_assert(*f(a2) == 2);
static_assert(*f(a3) == 3);
static_assert(*f(a4) == 4);
static_assert(*g<4>(a1) == 41);
static_assert(*g<5>(a2) == 52);
static_assert(*g<6>(a3) == 63);
static_assert(*g<7>(a1) == 71);
static_assert(*g<8>(a4) == 84);