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Re: How to find the problem in the object file

From David Brown <david.brown@hesbynett.no>
Newsgroups comp.lang.c
Subject Re: How to find the problem in the object file
Date 2017-01-27 16:20 +0100
Organization A noiseless patient Spider
Message-ID <o6fodf$int$1@dont-email.me> (permalink)
References (2 earlier) <2beebc58-3f8f-46c6-bd10-e2ec3cf87906@googlegroups.com> <o6d2ai$bcf$1@dont-email.me> <a72e083a-064a-4eca-b37a-c8950ba5289a@googlegroups.com> <o6dubf$8da$1@dont-email.me> <9f1b3da2-a9d1-45b3-8750-de69d5038e71@googlegroups.com>

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On 27/01/17 15:08, Alla _ wrote:
> On Friday, January 27, 2017 at 1:50:09 AM UTC+3, David Brown wrote:
>> On 26/01/17 17:29, Alla _ wrote:
>>
>>> Not me - Apple has changed gcc for clang. But I still use gcc command,
>>> clang knows how to interpret that.
>>> -Wall -Werror -Wextra -pedantic -std=c99 ...
>>
>> (As has been pointed out, you /are/ using clang.  clang accepts pretty 
>> much the same set of flags as gcc.  The list I give below is for gcc, 
>> based on the flag sets I use - I hope they match clang here.)
>>
>> Those flags are fine as a starting point - but you can get more help 
>> from your compiler with more flags.  Because different people write code 
>> in different ways, and some warnings trigger on legal C that some people 
>> think is perfectly good, additional warnings are not included in the 
>> "-Wall -Wextra" sets.  It is up to the individual programmer (or project 
>> manager, etc.) to decide the details here.  But here are a few 
>> suggestions for additional or alternative flags that you might find 
>> helpful - I certainly do:
>>
>>
>> Consider using -std=c11.  For the kind of code you are writing, c11 does 
>> not add much - but it is the current standard.  The key benefit that I 
>> see is the _Static_assert() feature.  Personally, I have no use for 
>> "-pedantic" and prefer "-std=gnu11" because I feel the gcc extensions 
>> let me write better and safer code - but for learning, it is best to 
>> stick as close as possible to the standards with -pedantic.
>>
>>
>> Additional warning flags:
>>
>> -Wlogical-op (Warns about odd-looking uses of logical operators)
>>
>> -Wredundant-decls (Warns about duplicate declarations)
>>
>> -Wmissing-prototypes -Wmissing-declarations (With these in place, your 
>> functions need to be either "static", or have a declarations before the 
>> definition - typically in a header)
>>
>> -Wundef (Warn if an undefined identifier is used in an #if directive)
>>
>> -Wnull-dereference (Warn if the compiler can spot a null deference when 
>> optimisation is on)
>>
>> -Wduplicated-branches -Wduplicated-cond (Warn about branches and 
>> conditionals that have the duplicates)
>>
>> -Wcast-qual -Wcast-align (Warn about some possible bad casts)
>>
>> I also recommend using -O1 to enable optimisation - it also enables 
>> better code analysis, and therefore better static error checking.
> 
> What a wonderful list! Thank you so much. 
> 

I have had a quick glance at clang's documentation, and I am not sure it
has these same warning flags.  Try it an see.

If possible, you might also consider getting gcc 6 (real gcc, not clang
with a gcc link) - it has a number of new warnings that add extra
warnings, such as "-Wmisleading-indentation" (part of -Wall) and
suggestions about some misspellings and other hints about the causes of
errors.

You can also use the "sanitize" options (in gcc and clang) to spot some
kinds of errors at run-time.

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Thread

How to find the problem in the object file Alla _ <modelling.data@gmail.com> - 2017-01-26 05:14 -0800
  Re: How to find the problem in the object file BartC <bc@freeuk.com> - 2017-01-26 13:22 +0000
    Re: How to find the problem in the object file BartC <bc@freeuk.com> - 2017-01-26 13:37 +0000
  Re: How to find the problem in the object file Richard Heathfield <rjh@cpax.org.uk> - 2017-01-26 13:53 +0000
    Re: How to find the problem in the object file Alla _ <modelling.data@gmail.com> - 2017-01-26 06:20 -0800
      Re: How to find the problem in the object file BartC <bc@freeuk.com> - 2017-01-26 14:28 +0000
        Re: How to find the problem in the object file Alla _ <modelling.data@gmail.com> - 2017-01-26 06:48 -0800
        Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-01-26 08:29 -0800
          Re: How to find the problem in the object file BartC <bc@freeuk.com> - 2017-01-26 16:54 +0000
            Re: How to find the problem in the object file luser droog <luser.droog@gmail.com> - 2017-01-26 09:01 -0800
            Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-01-26 11:20 -0800
            Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-01-26 23:12 +0100
              Re: How to find the problem in the object file BartC <bc@freeuk.com> - 2017-01-27 01:32 +0000
                Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-01-27 09:50 +0100
          Re: How to find the problem in the object file supercat@casperkitty.com - 2017-01-26 09:19 -0800
            Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-01-26 11:21 -0800
              Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-02 02:39 -0800
                Re: How to find the problem in the object file fir <profesor.fir@gmail.com> - 2017-02-02 04:08 -0800
                Re: How to find the problem in the object file fir <profesor.fir@gmail.com> - 2017-02-02 04:31 -0800
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-04 10:48 -0800
                Re: How to find the problem in the object file fir <profesor.fir@gmail.com> - 2017-02-04 11:07 -0800
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-02 10:22 -0800
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-04 11:00 -0800
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-04 14:14 -0800
                Re: How to find the problem in the object file Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-02-04 20:02 -0800
                Re: How to find the problem in the object file supercat@casperkitty.com - 2017-02-05 13:39 -0800
                Re: How to find the problem in the object file Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-02-05 13:44 -0800
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-05 13:56 -0800
                Re: How to find the problem in the object file Ian Collins <ian-news@hotmail.com> - 2017-02-06 13:07 +1300
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-05 16:14 -0800
                Re: How to find the problem in the object file Ian Collins <ian-news@hotmail.com> - 2017-02-06 13:24 +1300
                Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-02-06 01:59 +0100
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-08 21:32 -0800
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-05 13:54 -0800
                Re: How to find the problem in the object file Ian Collins <ian-news@hotmail.com> - 2017-02-06 11:18 +1300
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-08 21:32 -0800
                Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-02-09 10:33 +0100
                Re: How to find the problem in the object file supercat@casperkitty.com - 2017-02-09 09:10 -0800
                Re: How to find the problem in the object file Ian Collins <ian-news@hotmail.com> - 2017-02-10 08:01 +1300
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-09 09:01 -0800
                Re: How to find the problem in the object file supercat@casperkitty.com - 2017-02-09 09:35 -0800
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-09 09:57 -0800
                Re: How to find the problem in the object file Jean-Marc Bourguet <jm@bourguet.org> - 2017-02-09 20:45 +0100
                Re: How to find the problem in the object file supercat@casperkitty.com - 2017-02-09 14:59 -0800
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-09 15:20 -0800
                Re: How to find the problem in the object file supercat@casperkitty.com - 2017-02-09 16:12 -0800
                Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-02-13 10:21 +0100
                Re: How to find the problem in the object file supercat@casperkitty.com - 2017-02-13 07:20 -0800
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-13 09:28 -0800
                Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-02-13 09:55 +0100
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-16 03:36 -0800
                Re: How to find the problem in the object file Jean-Marc Bourguet <jm@bourguet.org> - 2017-02-09 20:56 +0100
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-16 07:00 -0800
                Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-02-16 20:03 +0100
                Re: How to find the problem in the object file Ian Collins <ian-news@hotmail.com> - 2017-02-17 09:22 +1300
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-16 13:07 -0800
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-24 09:21 -0800
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-24 09:02 -0800
                Re: How to find the problem in the object file Ian Collins <ian-news@hotmail.com> - 2017-02-25 09:05 +1300
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-24 09:26 -0800
                Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-02-25 19:38 +0100
                Re: How to find the problem in the object file Ian Collins <ian-news@hotmail.com> - 2017-02-03 07:32 +1300
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-04 11:24 -0800
                Re: How to find the problem in the object file Robert Wessel <robertwessel2@yahoo.com> - 2017-02-02 16:56 -0600
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-04 11:12 -0800
                Re: How to find the problem in the object file Robert Wessel <robertwessel2@yahoo.com> - 2017-02-06 04:47 -0600
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-08 21:59 -0800
                Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-02-09 09:13 -0800
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-15 19:28 -0800
                Re: How to find the problem in the object file Malcolm McLean <malcolm.mclean5@btinternet.com> - 2017-02-24 17:48 -0800
                Re: How to find the problem in the object file Tim Rentsch <txr@alumni.caltech.edu> - 2017-02-25 17:36 -0800
      Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-01-26 15:51 +0100
        Re: How to find the problem in the object file Alla _ <modelling.data@gmail.com> - 2017-01-26 08:29 -0800
          Re: How to find the problem in the object file Richard Heathfield <rjh@cpax.org.uk> - 2017-01-26 16:34 +0000
            Re: How to find the problem in the object file Alla _ <modelling.data@gmail.com> - 2017-01-26 09:48 -0800
          Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-01-26 08:52 -0800
          Re: How to find the problem in the object file James Kuyper <jameskuyper@verizon.net> - 2017-01-26 13:53 -0500
            Re: How to find the problem in the object file supercat@casperkitty.com - 2017-01-26 11:00 -0800
          Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-01-26 23:49 +0100
            Re: How to find the problem in the object file Alla _ <modelling.data@gmail.com> - 2017-01-27 06:08 -0800
              Re: How to find the problem in the object file David Brown <david.brown@hesbynett.no> - 2017-01-27 16:20 +0100
        Re: How to find the problem in the object file Keith Thompson <kst-u@mib.org> - 2017-01-26 08:41 -0800
          Re: How to find the problem in the object file m.labanowicz@gmail.com - 2017-01-27 01:26 -0800

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