https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85425
--- Comment #2 from Gerhard Heinzel <gerhard.heinzel at aei dot mpg.de> ---
(In reply to Jonathan Wakely from comment #1)
Many thanks for your quick response.
I normally don't use -Wconversion because it floods me with
uninteresting errors about size_t, floor(), and code from bison/flex etc.
But I'll try to use it more now.
Cheers,
Gerhard
> The example can be reduced to:
>
> void ghhrobust_search (double ay, int type) { }
>
> void f(int i, double d) { ghhrobust_search(i, d); }
>
> This must not produce an error, because it is 100% valid according to the C
> standard. An int can be converted to a double and a double can be converted
> to an int, so the code is valid.
>
> If you use -Wconversion you get a warning:
>
>
> a.c: In function ‘void f(int, double)’:
> a.c:3:48: warning: conversion to ‘int’ from ‘double’ may alter its value
> [-Wfloat-conversion]
> void f(int i, double d) { ghhrobust_search(i, d); }
> ^
>
> This seems to be what you're looking for. Indeed, compiling your attached
> code with -Wconversion gives a warning on the relevant line:
>
> fail_contour.c: In function ‘contour_trace’:
> fail_contour.c:203:56: warning: conversion to ‘int’ from ‘double’ may alter
> its value [-Wfloat-conversion]
