Hi all,
In C & C++, Apple's gcc 4.2 produces 2 warnings for this code with -
Wshorten-64-to-32:
int main(int,char**)
{
double d = 1.0;
float f = d; // warning: 64 to 32
long s1 = 10;
long s2 = 20;
int diff = s2 - s1; // warning: 64 to 32
return 0;
}
clang (trunk) only warns for the integer case. Is there a way to get
warnings for the double->float conversion too?
Thanks,
The generic "warn about any implicit conversions that might lose precision"
warning is -Wconversion. Clang's implementation of that is similar to
gcc-4.3's, i.e. substantially better than gcc-4.2's.
-Wshorten-64-to-32 was never supposed to be more than a portability
warning, which is why I didn't warn about double->float in clang's
implementation. Note that -Wshorten-64-to-32 is implied by -Wconversion.
John.
Ahh, that's good news. I'm used to thinking of -Wconversion as useless,
since it is in Apple's gcc 4.2.
Am I looking in the wrong place for warning docs? I don't see -
Wconversion here:
<http://clang.llvm.org/docs/UsersManual.html>
Cheers,
The generic "warn about any implicit conversions that might lose precision"
warning is -Wconversion. Clang's implementation of that is similar to
gcc-4.3's, i.e. substantially better than gcc-4.2's.Ahh, that's good news. I'm used to thinking of -Wconversion as useless,
since it is in Apple's gcc 4.2.
Well, let us know if you have any problems with false positives.
Am I looking in the wrong place for warning docs? I don't see -
Wconversion here:
Right now, we don't have any good documentation for the set of
warning categories we support.
John.