[Bug c/55546] New: Static functions that are fully inlined can end up in the object file

[Bug c/55546] New: Static functions that are fully inlined can end up in the object file

[rohan at rohanlean dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55546

             Bug #: 55546
           Summary: Static functions that are fully inlined can end up in
                    the object file
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: rohan@rohanlean.de


Created attachment 28838
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28838
A rather minimal test-case for the bug.

If a static function has its address taken in the C code, but due to
optimisations the address is never used, then the function can still end up in
the object file.  I have attached a file to demonstrate the bug.  When I
compile it with -std=c11 -O3, the resulting executable will contain code for f,
even though it is not needed.  (As an aside, if you add another function
similar to f, and call h with each of them, then gcc will not resolve things so
nicely at compile time and also emit code for h.)

[Bug middle-end/55546] Static functions that are fully inlined can end up in the object file

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55546

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
           Keywords|                            |missed-optimization
   Last reconfirmed|                            |2012-12-03
          Component|c                           |middle-end
                 CC|                            |hubicka at gcc dot gnu.org,
                   |                            |rguenth at gcc dot gnu.org
     Ever Confirmed|0                           |1
      Known to fail|                            |4.8.0
           Severity|normal                      |enhancement

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> 2012-12-03 11:49:41 UTC ---
That can trivially happen if the not usedness address-taken is discovered
too late by the compiler to temove the function.

Testcase confirmed.