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Groups > comp.lang.c > #151899
| From | Ian Collins <ian-news@hotmail.com> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: This statement may fall through - how? |
| Date | 2020-05-01 12:44 +1200 |
| Message-ID | <hh19moFpf1aU8@mid.individual.net> (permalink) |
| References | (1 earlier) <hgukkrFpf1aU6@mid.individual.net> <87imhh7pk8.fsf@nosuchdomain.example.com> <r8fcfn$fmn$1@dont-email.me> <seErO5Tpfw5MbWWICM@bongo-ra.co> <r8fmii$htv$1@dont-email.me> |
On 01/05/2020 11:21, mathog wrote:
> On 4/30/20 2:09 PM, Spiros Bousbouras wrote:
>> I assumed that the "C++11" Keith wrote was a typo and he meant "C11". If this
>> really is about C++ then why are you asking here and not on comp.lang.c++ ?
>
> The package is mostly C, I just didn't notice that this file happened to
> be C++.
>
> I have reduced it to a test case in C which does the same thing:
>
>
> cat >test.c <<'EOD'
> #include <stdlib.h>
> #include <stdio.h>
> #include <unistd.h>
>
> void usage(void);
> void parse_command_line(int argc, char* argv[]);
>
>
> int main(int argc, char* argv[]){
> parse_command_line(argc,argv);
> printf("done\n");
> exit(EXIT_SUCCESS);
> }
>
> void usage()
> {
> printf("usage string\n");
> exit(0);
> }
>
> void parse_command_line(int argc, char* argv[])
> {
> int opt;
>
> while ( (opt = getopt(argc, argv, "i:o:hw:te") ) != -1 ) {
> switch(opt) {
> case 'h':
> usage();
>
> default:
> printf("anything else\n");
> break;
> }
> }
> }
> EOD
> gcc -Wall -Wextra -o test test.c
> test.c: In function ‘parse_command_line’:
> test.c:28:9: warning: this statement may fall through
> [-Wimplicit-fallthrough=]
> usage();
> ^~~~~~~
> test.c:30:7: note: here
> default:
> ^~~~~~~
clang suggests some of the fixes already proposed here:
test.c:30:8: warning: unannotated fall-through between switch labels
[-Wimplicit-fallthrough]
default:
^
test.c:30:8: note: insert '__attribute__((fallthrough));' to silence
this warning
default:
^
__attribute__((fallthrough));
test.c:30:8: note: insert 'break;' to avoid fall-through
default:
^
break;
--
Ian.
Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar
This statement may fall through - how? mathog <mathog@caltech.edu> - 2020-04-29 17:18 -0700
Re: This statement may fall through - how? Ian Collins <ian-news@hotmail.com> - 2020-04-30 12:32 +1200
Re: This statement may fall through - how? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-29 18:03 -0700
Re: This statement may fall through - how? Ian Collins <ian-news@hotmail.com> - 2020-04-30 14:01 +1200
Re: This statement may fall through - how? mathog <mathog@caltech.edu> - 2020-04-30 13:29 -0700
Re: This statement may fall through - how? Spiros Bousbouras <spibou@gmail.com> - 2020-04-30 21:09 +0000
Re: This statement may fall through - how? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-30 15:19 -0700
Re: This statement may fall through - how? mathog <mathog@caltech.edu> - 2020-04-30 16:21 -0700
Re: This statement may fall through - how? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-30 17:27 -0700
Re: This statement may fall through - how? Ian Collins <ian-news@hotmail.com> - 2020-05-01 12:44 +1200
Re: This statement may fall through - how? mathog <mathog@caltech.edu> - 2020-05-01 10:28 -0700
Re: This statement may fall through - how? chad <cdalten@gmail.com> - 2020-05-01 12:43 -0700
Re: This statement may fall through - how? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-04-29 17:58 -0700
Re: This statement may fall through - how? scott@slp53.sl.home (Scott Lurndal) - 2020-04-30 01:25 +0000
Re: This statement may fall through - how? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-29 18:37 -0700
Re: This statement may fall through - how? Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 10:33 +0200
Re: This statement may fall through - how? gazelle@shell.xmission.com (Kenny McCormack) - 2020-04-30 08:48 +0000
Re: This statement may fall through - how? Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 10:54 +0200
Re: This statement may fall through - how? James Harris <james.harris.1@gmail.com> - 2020-04-30 10:03 +0100
Re: This statement may fall through - how? Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 11:08 +0200
Re: This statement may fall through - how? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-30 02:15 -0700
Re: This statement may fall through - how? James Harris <james.harris.1@gmail.com> - 2020-04-30 12:27 +0100
Re: This statement may fall through - how? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-04-30 13:42 +0100
Re: This statement may fall through - how? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-04-30 10:26 -0400
Re: This statement may fall through - how? James Harris <james.harris.1@gmail.com> - 2020-04-30 17:43 +0100
Re: This statement may fall through - how? James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-04-30 13:01 -0400
Re: This statement may fall through - how? Spiros Bousbouras <spibou@gmail.com> - 2020-04-30 17:34 +0000
Re: This statement may fall through - how? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-04-30 13:53 -0400
Re: This statement may fall through - how? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-04-30 13:21 -0700
Re: This statement may fall through - how? scott@slp53.sl.home (Scott Lurndal) - 2020-04-30 17:54 +0000
Re: This statement may fall through - how? chad <cdalten@gmail.com> - 2020-04-30 10:55 -0700
Re: This statement may fall through - how? Richard Damon <Richard@Damon-Family.org> - 2020-04-30 10:30 -0400
Re: This statement may fall through - how? gazelle@shell.xmission.com (Kenny McCormack) - 2020-04-30 09:10 +0000
Re: This statement may fall through - how? Bonita Montero <Bonita.Montero@gmail.com> - 2020-04-30 11:18 +0200
Re: This statement may fall through - how? mathog <mathog@caltech.edu> - 2020-04-30 13:13 -0700
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