Re: This statement may fall through - how?

From	Ian Collins <ian-news@hotmail.com>
Newsgroups	comp.lang.c
Subject	Re: This statement may fall through - how?
Date	2020-04-30 12:32 +1200
Message-ID	<hgukkrFpf1aU6@mid.individual.net> (permalink)
References	<r8d5h9$qe1$1@dont-email.me>

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On 30/04/2020 12:18, mathog wrote:
> The code snippet below my signature generates this message when compiled:
> 
> g++ -DHAVE_CONFIG_H -I. -I../..
> -I/usr/common/modules/el8/x86_64/software/libgtextutils/0.7-CentOS-vanilla/include/gtextutils
>    -I../../src/libfastx   -g -O2 -Wall -Wextra -Wformat-nonliteral
> -Wformat-security -Wswitch-default -Wswitch-enum -Wunused-parameter
> -Wfloat-equal -Werror -DDEBUG -g -O1 -MT fasta_formatter.o -MD -MP -MF
> .deps/fasta_formatter.Tpo -c -o fasta_formatter.o fasta_formatter.cpp
> fasta_formatter.cpp: In function ‘void parse_command_line(int, char**)’:
> fasta_formatter.cpp:105:9: error: this statement may fall through
> [-Werror=implicit-fallthrough=]
>       usage();
>       ~~~~~^~
> fasta_formatter.cpp:107:3: note: here
>      case 'i':
>      ^~~~
> 
> This is with gcc 8.3.1.  Is there really some way that usage() can avoid
> hitting exit() or is the compiler just emitting a general warning
> without actually looking at usage()?

If you are using gcc; __attribute__ ((noreturn))?

-- 
Ian

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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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