[Bug c++/105280] New: g++ does not raise sign-comapre in static_assert under some conditions

[cfy1990 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105280

            Bug ID: 105280
           Summary: g++ does not raise sign-comapre in static_assert under
                    some conditions
           Product: gcc
           Version: 11.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: cfy1990 at gmail dot com
  Target Milestone: ---

g++ does not raise sign-compare warnings in static_assert((-1 >= 1u) &&
T1<T>::v, "");

Code link: https://godbolt.org/z/4GjT9f5oz
Compile arguments:  -O2 -std=c++11 -Wall -Wextra -Wconversion -Wsign-conversion
-Wunused-result  -Wsign-compare -Wlogical-not-parentheses -Wdouble-promotion

Code:

template<typename T>
struct T1;

template<>
struct T1<unsigned int>{
    const static bool v=true;
};

template<typename T>
void foo(__attribute__((unused)) T v){
    // should generate warning, but not in g++
    // clang works fine
    static_assert((-1 >= 1u) && T1<T>::v, "");

    // codes works fine in gcc and clang
    static_assert((-1 >= 1u) && T1<unsigned>::v, ""); // sign-compare warning

    static_assert((-1 >= 1u), ""); // sign-compare warning

    constexpr bool b = (-1 >= 1u) && T1<T>::v; // sign-compare warning
    static_assert(b, "");

    static_assert((!3 > -1) && T1<T>::v, ""); // logical-not-parentheses
warning
    static_assert((1.0f*3.0 > 0) && T1<T>::v, ""); // double-promotion warning
}

void bar(){
    static_assert((-1 >= 1u) && T1<unsigned int>::v, ""); // sign-compare
warning
    foo(2u);
}