[Bug c++/11530] New: inline static function not emitted with -O3

[Bug c++/11530] New: inline static function not emitted with -O3

[gcc-bugzilla at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11530

           Summary: inline static function not emitted with -O3
           Product: gcc
           Version: 3.4
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: snyder at fnal dot gov
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: i686-pc-linux-gnu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


For the program below, g++ 3.4 does not emit code for RunState::runcallback,
if compiled with -O3:

$ g++ -O3 -o x x.cc
/tmp/cc4LLDSK.o: In function `main':
/tmp/cc4LLDSK.o(.text+0x1a): undefined reference to `RunState::runcallback()'
collect2: ld returned 1 exit status
$
$ g++ -c -O3 x.cc
$ nm -Bo x.o
x.o:00000000 T _Z1aPFvvE
x.o:         U _ZN8RunState11runcallbackEv
x.o:         U __gxx_personality_v0
x.o:00000010 T main
$

Environment:
System: Linux karma 2.4.19-emp_2419p5a829i #1 Tue Sep 3 17:42:17 EST 2002 i686 i686 i386 GNU/Linux
Architecture: i686

	<machine, os, target, libraries (multiple lines)>
host: i686-pc-linux-gnu
build: i686-pc-linux-gnu
target: i686-pc-linux-gnu
configured with: ../gcc/configure --prefix=/usr/local/gcc --enable-threads=posix --enable-long-long --enable-languages=c,c++,f77 : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)  : (reconfigured)

How-To-Repeat:

Compile with -O3:

-----------------------------------------------------------------
void a (void (*f)())
{
  f();
}

struct RunState
{
  static void runcallback() { }
  static void wait()
  {
    a (runcallback);
  }
};

int main()
{
  RunState::wait();
  return 0;
}
-----------------------------------------------------------------
------- Additional Comments From snyder at fnal dot gov  2003-07-15 21:19 -------
Fix:
	<how to correct or work around the problem, if known (multiple lines)>

[Bug c++/11530] [3.4 regression] unit-at-a-time: inline static function not emitted with -O3

[bangerth at dealii dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11530


bangerth at dealii dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |hubicka at gcc dot gnu dot
                   |                            |org
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2003-07-15 22:14:02
               date|                            |
            Summary|inline static function not  |[3.4 regression] unit-at-a-
                   |emitted with -O3            |time: inline static function
                   |                            |not emitted with -O3


------- Additional Comments From bangerth at dealii dot org  2003-07-15 22:14 -------
Confirmed. It is a unit-at-a-time problem, since
if I specify -fno-unit-at-a-time, the problem goes away.

That also implies that it is not related to PR 10804 and PR 10384 that
seem to be similar, but predate unit-at-a-time (and don't benefit from
giving that flag).

W.

[Bug c++/11530] [3.4 regression] [unit-at-a-time] inline static function not emitted with -O3

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11530


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |critical
           Keywords|                            |wrong-code
           Priority|P3                          |P1
            Summary|[3.4 regression] unit-at-a- |[3.4 regression] [unit-at-a-
                   |time: inline static function|time] inline static function
                   |not emitted with -O3        |not emitted with -O3
   Target Milestone|---                         |3.4


------- Additional Comments From pinskia at physics dot uc dot edu  2003-07-15 23:09 -------
It looks like if the function is referenced in not in a call, unit-at-a-time does not mark the 
function as being used as gcc does not emit it.

[Bug c++/11530] [3.4 regression] [unit-at-a-time] inline static function not emitted with -O3

[steven at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11530


steven at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|hubicka at gcc dot gnu dot  |
                   |org                         |
         AssignedTo|unassigned at gcc dot gnu   |hubicka at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED


------- Additional Comments From steven at gcc dot gnu dot org  2003-07-18 22:37 -------
Jan, this looks like a case you really want to take on.

[Bug c++/11530] [3.4 regression] [unit-at-a-time] inline static function not emitted with -O3

[janis187 at us dot ibm dot com]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11530



------- Additional Comments From janis187 at us dot ibm dot com  2003-07-24 19:36 -------
The regression in PR 11530 was introduced or exposed by this patch
(perhaps obvious, but this confirms that it wasn't caused a later
change):

--- gcc/gcc/ChangeLog ---

Wed Jul  2 02:12:51 CEST 2003  Jan Hubicka  <jh@suse.cz>

        * cgraphunit.c (cgraph_finalize_function): Set finalized.
        (cgraph_finalize_function): Do not examine inlinablility.
        (cgraph_finalize_compilation_unit): Do it here.
        * cgraph.h (cgraph_local_info): Add finalized field.

--- gcc/gcc/cp/ChangeLog ---

Wed Jul  2 00:36:48 CEST 2003  Jan Hubicka  <jh@suse.cz>

        * decl2.c (defer_fn): Set DECL_DEFER_OUTPUT.
        (finish-file): Do not process function with DECL_DEFER_OUTPUT clear;
        clear DECL_DEFER_OUTPUT once function is processed; avoid flags
        massaging.

        * cp-tree.h (DECL_NEEDED_P): Support unit-at-a-time
        (expand_or_defer_fn): Declare.
        (lower_function): Declare.
        * decl.c (start_cleanup_fn): Use expand_or_defer_fn.
        * decl2.c: Include cgraph.h and varpool.h
        (maybe_emit_vtables):  Make explicit instantations as needed.
        (mark_member_pointers, lower_function): New functions.
        (finish_file): Do unit-at-a-time.
        * method.c (synthesize_method): Use expand_or_defer_fn.
        * optimize.c (maybe_clone_body): Use expand_or_defer_fn.
        * parser.c (cp_parser_function_definition_after_decl): Use
        expand_or_defer_fn.
        * pt.c (instantiate_decl): Likewise.
        * semantics.c: Include cgraph.h
        (expand_or_defer_fn): Break out from ...
        (expand_body): ... here; deal with unit-at-a-time.
        * cp-lang.c (LANG_HOOKS_CALLGRAPH_EXPAND_FUNCTION,
        LANG_HOOKS_CALLGRAPH_LOWER_FUNCTION): Define.

The regression hunt used the submitter's test case on i686-pc-linux-gnu
compiled with -O3.

[Bug c++/11530] [3.4 regression] [unit-at-a-time] inline static function not emitted with -O3

[cvs-commit at gcc dot gnu dot org]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11530



------- Additional Comments From cvs-commit at gcc dot gnu dot org  2003-07-29 01:57 -------
Subject: Bug 11530

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	mmitchel@gcc.gnu.org	2003-07-29 01:57:48

Modified files:
	gcc/cp         : ChangeLog parser.c semantics.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/g++.dg/opt: call1.C 

Log message:
	PR c++/11530
	* parser.c (cp_parser_postfix_expression): Do not call mark_used.
	* semantics.c (finish_id_expression): Call mark_used for all
	declarations.
	
	PR c++/11530
	* g++.dg/opt/call1.C: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.3564&r2=1.3565
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/parser.c.diff?cvsroot=gcc&r1=1.90&r2=1.91
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/semantics.c.diff?cvsroot=gcc&r1=1.337&r2=1.338
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.2926&r2=1.2927
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/opt/call1.C.diff?cvsroot=gcc&r1=NONE&r2=1.1

[Bug c++/11530] [3.4 regression] [unit-at-a-time] inline static function not emitted with -O3

[pinskia at physics dot uc dot edu]

PLEASE REPLY TO gcc-bugzilla@gcc.gnu.org ONLY, *NOT* gcc-bugs@gcc.gnu.org.

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11530


pinskia at physics dot uc dot edu changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED


------- Additional Comments From pinskia at physics dot uc dot edu  2003-07-29 05:12 -------
Fixed by the patch above:
2003-07-28  Mark Mitchell

        PR c++/11530
        * parser.c (cp_parser_postfix_expression): Do not call mark_used.
        * semantics.c (finish_id_expression): Call mark_used for all
        declarations.
Which already included a test.