Attachment 2443 Details for Bug 2968 – minmax.c

minmax.c

minmax.c (text/plain), 4.06 KB, created by Mike A. Harris on 2005-04-18 05:07:34 UTC

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Creator: Mike A. Harris

Created: 2005-04-18 05:07:34 UTC

Size: 4.06 KB

patch

obsolete

>/*
> * Test cases for comparing results of different min()/max() implementations
> * with different compilers.  -- Mike A. Harris <mharris@www.linux.org.uk>
> *
> * Compile with:  gcc -Wall -o minmax minmax.c
> */
>
>#include <stdio.h>
>
>/*
> * gccmin()/gccmax() macros are replacements for min()/max() which perform
> * strict type checking using gcc's typeof extension, and prevent double
> * execution of arguments.
> */
>#define gccmin(x,y) ({ \
>        typeof(x) _x = (x); \
>        typeof(y) _y = (y); \
>        (void) (&_x == &_y); \
>        _x < _y ? _x : _y; })
>
>#define gccmax(x,y) ({ \
>        typeof(x) _x = (x); \
>        typeof(y) _y = (y); \
>        (void) (&_x == &_y); \
>        _x > _y ? _x : _y; })
>
>/*
> * gccminnoprot()/gccmaxnoprot() macros are replacements for min()/max()
> * which perform strict type checking using gcc's typeof extension, but
> * do NOT prevent double execution of arguments.
> */
>#define gccminnoprot(x,y) ({ \
>        typeof(x) _x = (x); \
>        typeof(y) _y = (y); \
>        (void) (&_x == &_y); \
>        _x < _y ? (x) : (y); })
>
>#define gccmaxnoprot(x,y) ({ \
>        typeof(x) _x = (x); \
>        typeof(y) _y = (y); \
>        (void) (&_x == &_y); \
>        _x > _y ? (x) : (y); })
>
>/*
> * min()/max() are traditional versions of these macros without type
> * checking or multiple execution protection.  These would be used in the
> * case where gcc isn't available.
> */
>#define min(x,y) ((x) < (y) ? (x) : (y))
>#define max(x,y) ((x) > (y) ? (x) : (y))
>
>/* Convenience macros */
>#define set_ab()	(a = 10, b = 20)
>#define set_xy()	(x = 10, y = 20)
>int main(void)
>{
>    int a, b, x;
>    long y;
>
>    printf("Test cases for same-type comparisons:\n");
>    set_ab();
>    printf("Traditional min/max without side effects:  min(a,b)=%d, max(a,b)=%d\n", min(a,b), max(a,b));
>    set_ab();
>    printf("gccmin/gccmax without side effects      :  min(a,b)=%d, max(a,b)=%d\n", gccmin(a,b), gccmax(a,b));
>    set_ab();
>    printf("Traditional min with side effects   :  min(a++,b++)=%d\n", min(a++,b++));
>    set_ab();
>    printf("Traditional max with side effects   :  max(a++,b++)=%d\n", max(a++,b++));
>    set_ab();
>    printf("gccmin with side effects            :  min(a++,b++)=%d\n", gccmin(a++,b++));
>    set_ab();
>    printf("gccmax with side effects            :  max(a++,b++)=%d\n", gccmax(a++,b++));
>
>    printf("\nTesting for mismatched type in min/max comparisons.\n");
>    set_xy();
>    printf("Traditional min/max without side effects:  min(x,y)=%ld, max(x,y)=%ld\n", min(x,y), max(x,y));
>    set_xy();
>    printf("gccmin/gccmax without side effects      :  min(x,y)=%ld, max(x,y)=%ld\n", gccmin(x,y), gccmax(x,y)); /* gcc issues warning at compile time here */
>    set_xy();
>    printf("Traditional min with side effects   :  min(x++,y++)=%ld\n", min(x++,y++));
>    set_xy();
>    printf("Traditional max with side effects   :  max(x++,y++)=%ld\n", max(x++,y++));
>    set_xy();
>    printf("gccmin with side effects            :  min(x++,y++)=%ld\n", gccmin(x++,y++)); /* gcc issues warning at compile time here */
>    set_xy();
>    printf("gccmax with side effects            :  max(x++,y++)=%ld\n", gccmax(x++,y++)); /* gcc issues warning at compile time here */
>
>    printf("\nTesting for mismatched type in min/max comparisons without double exec protection.\n");
>    set_xy();
>    printf("Traditional min/max without side effects :  min(x,y)=%ld, max(x,y)=%ld\n", min(x,y), max(x,y));
>    set_xy();
>    printf("gccmin/gccmax noprot without side effects:  min(x,y)=%ld, max(x,y)=%ld\n", gccminnoprot(x,y), gccmaxnoprot(x,y)); /* gcc issues warning at compile time here */
>    set_xy();
>    printf("Traditional min with side effects        :  min(x++,y++)=%ld\n", min(x++,y++));
>    set_xy();
>    printf("Traditional max with side effects        :  max(x++,y++)=%ld\n", max(x++,y++));
>    set_xy();
>    printf("gccminnoprot with side effects           :  min(x++,y++)=%ld\n", gccminnoprot(x++,y++)); /* gcc issues warning at compile time here */
>    set_xy();
>    printf("gccmaxnoprot with side effects           :  max(x++,y++)=%ld\n", gccmaxnoprot(x++,y++)); /* gcc issues warning at compile time here */
>
>    return 0;
>}

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