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* [Bug c/60725] New: [-Wreturn-type] false positive in trivial switch
@ 2014-04-01  8:37 skvadrik at gmail dot com
  2014-04-01 13:52 ` [Bug middle-end/60725] " mpolacek at gcc dot gnu.org
                   ` (3 more replies)
  0 siblings, 4 replies; 5+ messages in thread
From: skvadrik at gmail dot com @ 2014-04-01  8:37 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60725

            Bug ID: 60725
           Summary: [-Wreturn-type] false positive in trivial switch
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: skvadrik at gmail dot com

Created attachment 32510
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32510&action=edit
wreturn_false_positive.c

Given this program (see attachment):

  // wreturn_false_positive.c
  enum E { E1 };
  static inline int f1(enum E e) {
      switch (e) {
          case E1: return 1;
      }
  }
  int main () {
      f1(E1);
      return 0;
  }

gcc generates warning:

$ gcc -Wall wreturn_false_positive.c 
wreturn_false_positive.c: In function ‘f1’:
wreturn_false_positive.c:9:1: warning: control reaches end of non-void function
[-Wreturn-type]

If I compile with '-fdump-tree-all', I see that gcc adds 'default' case to
switch very early (in .gimple), and later it cannot get rid of that 'default'
path. Why does gcc add default case?
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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug lto/60721] xcoral fails to build with LTO: internal compiler error: verify_flow_info failed
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id`721

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
IMHO we need a flag on each gimple call whether that call instance is supposed
to be 'leaf' or not, similar to how we have noreturn and nothrow flags here.


^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2015-09-04 18:46 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2014-04-01  8:37 [Bug c/60725] New: [-Wreturn-type] false positive in trivial switch skvadrik at gmail dot com
2014-04-01 13:52 ` [Bug middle-end/60725] " mpolacek at gcc dot gnu.org
2015-09-04 15:26 ` jens.auer at cgi dot com
2015-09-04 17:41 ` manu at gcc dot gnu.org
2015-09-04 18:46 ` manu at gcc dot gnu.org

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