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Re: Incompatible pointer types with GCC

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On 16/12/2016 10:41, August Karlstrom wrote:
> My question is whether this is a valid ANSI C (C89) program or not:
>
>     typedef int Row[10];
>
>     void P(const Row A[])
>     {
>     }
>
>
>     int main(void)
>     {
>         Row A[10];
>
>         P(A);
>         return 0;
>     }
>
> It compiles cleanly with Clang 3.5.0 and the options -pedantic -std=c89
> -Wall.
>
> GCC 4.9.2, however, is not happy:
>
> $ gcc -c -o test.o -g -pedantic -std=c89 -Wall test.c
> test.c: In function ‘main’:
> test.c:12:4: warning: passing argument 1 of ‘P’ from incompatible
> pointer type
>   P(A);
>     ^
> test.c:3:6: note: expected ‘const int (*)[10]’ but argument is of type
> ‘int (*)[10]’
>  void P(const Row A[])
>       ^
>
> Any clues?

I get:

c.c:16:9: warning: pointers to arrays with different qualifiers are 
incompatible in ISO C [-Wpedantic]
          P(A);
          ^

I suspect that, because of the typedef 'Row', the 'const' doesn't apply 
to the bit that you think it does. Try dumping 'const' for now and add 
it later when the program works.

Or remove the typedef which I think causes problems with arrays.

-- 
Bartc

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Incompatible pointer types with GCC August Karlstrom <fusionfile@gmail.com> - 2016-12-16 11:41 +0100
  Re: Incompatible pointer types with GCC BartC <bc@freeuk.com> - 2016-12-16 11:06 +0000
  Re: Incompatible pointer types with GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-16 17:07 +0000
    Re: Incompatible pointer types with GCC August Karlstrom <fusionfile@gmail.com> - 2016-12-16 23:02 +0100
      Re: Incompatible pointer types with GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-17 00:48 +0000
      Re: Incompatible pointer types with GCC martin.uecker@med.uni-goettingen.de - 2016-12-18 08:06 -0800
        Re: Incompatible pointer types with GCC Ben Bacarisse <ben.usenet@bsb.me.uk> - 2016-12-18 20:11 +0000
          Re: Incompatible pointer types with GCC supercat@casperkitty.com - 2016-12-18 14:43 -0800
            Re: Incompatible pointer types with GCC Tim Rentsch <txr@alumni.caltech.edu> - 2016-12-29 13:33 -0800

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