Missing dangling warnings for normal local array returned as std::span

[hokein]

See the example: https://godbolt.org/z/nnjKszT4c

I think the reason is that we don't know the type abc2 is gsl-owner.

#include <span>
#include <vector>

using namespace std;

span<const int> func1() {
  int abc2[10];
  return abc2; // bad, no dangling warning
}

span<const int> func2() {
  std::vector<int> abc;
  return abc; // good, danging warning.
}

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Haojian Wu (hokein)

See the example: https://godbolt.org/z/nnjKszT4c

I think the reason is that we don't know the type abc2 is gsl-owner.

#include <span>
#include <vector>

using namespace std;

span<const int> func1() {
  int abc2[10];
  return abc2; // bad, no dangling warning
}

span<const int> func2() {
  std::vector<int> abc;
  return abc; // good, danging warning.
}

[hokein]

Another example is:

std::string_view TestZoneName() {
   char test[] = "foo";
   return test;
}