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* [Bug c++/53960] New: Add warning about implicit fallthrough in switch
@ 2012-07-14 4:35 david at doublewise dot net
2012-07-14 4:53 ` [Bug c++/53960] " pinskia at gcc dot gnu.org
2012-07-14 4:54 ` pinskia at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: david at doublewise dot net @ 2012-07-14 4:35 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53960
Bug #: 53960
Summary: Add warning about implicit fallthrough in switch
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: c++
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: david@doublewise.net
A helpful warning that should catch real bugs would be to warn for cases of
implicit fallthrough in a switch statement in C / C++. This warning is
currently implemented in clang. However, I feel that their implementation is
flawed, and we can do it a little better. It is idiomatic C / C++ to do
something like this, which should not be warned about:
switch(n) {
case 0:
case 1: // Implicit fallthrough, but obviously intended
do_something();
break;
default:
break;
}
Perhaps we should add two sets of warnings? Something like
-Wimplicit-fall-through and -Wimplicit-fall-through-empty-case? The second
warning would be identical to the clang warning, which warns whenever a case in
a switch does not end in something like break or return, while the first
warning is the (much more useful) warning only if a case is not completely
empty.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c++/53960] Add warning about implicit fallthrough in switch
2012-07-14 4:35 [Bug c++/53960] New: Add warning about implicit fallthrough in switch david at doublewise dot net
@ 2012-07-14 4:53 ` pinskia at gcc dot gnu.org
2012-07-14 4:54 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2012-07-14 4:53 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53960
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-07-14 04:52:49 UTC ---
I have seen this request before ...
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c++/53960] Add warning about implicit fallthrough in switch
2012-07-14 4:35 [Bug c++/53960] New: Add warning about implicit fallthrough in switch david at doublewise dot net
2012-07-14 4:53 ` [Bug c++/53960] " pinskia at gcc dot gnu.org
@ 2012-07-14 4:54 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2012-07-14 4:54 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53960
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |DUPLICATE
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-07-14 04:54:03 UTC ---
Yep, an old bug report 7652.
*** This bug has been marked as a duplicate of bug 7652 ***
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-07-14 4:35 [Bug c++/53960] New: Add warning about implicit fallthrough in switch david at doublewise dot net
2012-07-14 4:53 ` [Bug c++/53960] " pinskia at gcc dot gnu.org
2012-07-14 4:54 ` pinskia at gcc dot gnu.org
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