[Bug c/46158] New: Spurious never executed warning

[Bug c/46158] New: Spurious never executed warning

[wkf at alum dot mit.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46158

           Summary: Spurious never executed warning
           Product: gcc
           Version: 4.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: wkf@alum.mit.edu


// test.cpp

#define testIt(expression)                        \
{                                    \
  if (expression) {                            \
      throw true;                            \
  }                                    \
}

void
useIt()
{
  bool eof = false;

  testIt(eof)
}

// End of test.cpp

--------------------------------------------

gcc --version; gcc -Werror -Wunreachable-code -o test.o test.cpp

--------------------------------------------

gcc (GCC) 4.2.1 20070719  [FreeBSD]
Copyright (C) 2007 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

cc1plus: warnings being treated as errors
test.cpp: In function 'void useIt()':
test.cpp:15: warning: will never be executed

[Bug c/46158] Spurious never executed warning

[wkf at alum dot mit.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46158

--- Comment #1 from William K Foster <wkf at alum dot mit.edu> 2010-10-24 19:59:23 UTC ---
Also, in a much more complicated test case (not provided) I get a much more
obtuse warning message that does not refer me to my file, but instead a header:

/usr/include/c++/4.2/bits/allocator.h: In copy constructor
'std::allocator<_Alloc>::allocator(const std::allocator<_Alloc>&) [with _Tp =
char]':
/usr/include/c++/4.2/bits/allocator.h:103: warning: will never be executed
/usr/include/c++/4.2/bits/allocator.h:102: warning: will never be executed
/usr/include/c++/4.2/ext/new_allocator.h: In copy constructor
'__gnu_cxx::new_allocator<_Tp>::new_allocator(const
__gnu_cxx::new_allocator<_Tp>&) [with _Tp = char]':
/usr/include/c++/4.2/ext/new_allocator.h:70: warning: will never be executed
/usr/include/c++/4.2/bits/allocator.h: In destructor
'std::allocator<_Alloc>::~allocator() [with _Tp = char]':
/usr/include/c++/4.2/bits/allocator.h:108: warning: will never be executed
/usr/include/c++/4.2/ext/new_allocator.h: In destructor
'__gnu_cxx::new_allocator<_Tp>::~new_allocator() [with _Tp = char]':
/usr/include/c++/4.2/ext/new_allocator.h:75: warning: will never be executed
/usr/include/c++/4.2/bits/allocator.h: In destructor
'std::allocator<_Alloc>::~allocator() [with _Tp = char]':
/usr/include/c++/4.2/bits/allocator.h:108: warning: will never be executed
gmake: *** [ARCH.freebsd_61_i86/debug/opFlume_delta.o] Error 1

[Bug c/46158] Spurious never executed warning

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46158

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |WONTFIX

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2010-10-25 21:01:51 UTC ---
-Wunreachable-code is broken and has been removed from GCC 4.5.  Do not use it.

[Bug middle-end/46158] Spurious never executed warning

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46158

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|c                           |middle-end
   Target Milestone|---                         |4.5.0