cpp: objects generate hypertarget names unexpectedly

[tk0miya]

Describe the bug
The C++ objects generate hyperlink names internally. As a result, it conflicts with normal hyperlink target.

To Reproduce
Input:

.. _say_hello:

.. cpp:function:: say_hello()

warnings:

/Users/tkomiya/work/tmp/doc/index.rst:14: WARNING: Duplicate explicit target name: "say_hello".

As a side effect, C++ objects can be refer via hyperlink reference syntax:

.. cpp:function:: say_hello()

Both :cpp:func:`say_hello` and say_hello_ can refer above definition

Expected behavior
I suppose this is not unexpected behavior. So it should not define hyperlink names internally.

Your project
N/A

Screenshots
N/A

Environment info

• OS: Mac
• Python version: 3.8.2
• Sphinx version: 2.4.4
• Sphinx extensions: No
• Extra tools: No