[Bug c++/84994] New: Missing accessor hint for private field at -O1 and above

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84994

            Bug ID: 84994
           Summary: Missing accessor hint for private field at -O1 and
                    above
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dmalcolm at gcc dot gnu.org
  Target Milestone: ---

Given this:

class foo
{
public:
  double get_ratio() const { return m_ratio; }

private:
  double m_ratio;
};

void test(foo *ptr)
{
  if (ptr->m_ratio >= 0.5)
    ;// etc
}

we emit an accessor hint at -O0:


<source>: In function 'void test(foo*)':
<source>:12:12: error: 'double foo::m_ratio' is private within this context
   if (ptr->m_ratio >= 0.5)
            ^~~~~~~
<source>:7:10: note: declared private here
   double m_ratio;
          ^~~~~~~
<source>:12:12: note: field 'double foo::m_ratio' can be accessed via 'double
foo::get_ratio() const'
   if (ptr->m_ratio >= 0.5)
            ^~~~~~~
            get_ratio()

but not at -O1 and above:

<source>: In function 'void test(foo*)':
<source>:12:12: error: 'double foo::m_ratio' is private within this context
   if (ptr->m_ratio >= 0.5)
            ^~~~~~~
<source>:7:10: note: declared private here
   double m_ratio;
          ^~~~~~~

[reported by user "flacs" as a comment on my blogpost here:
https://developers.redhat.com/blog/2018/03/15/gcc-8-usability-improvements/ ]