warning: 'sv' may be used uninitialized in this function
Posted: 2011-02-15T13:29:52-07:00
Appears in many functions.Magick.c: In function 'XS_Image__Magick_Transform':
Magick.xs:13522:8: warning: 'sv' may be used uninitialized in this function
The first problem with these messages is lack of locality. At least within Transform, sv is a temporary variable used in an inner block, and it should be declared in block scope.
The second problem is that it is initialised by the macro AddImageToRegistry, which is as bad coding style as can be (macro name is CamelCase, the name sv is hardwired, side effects invisible and context-dependent). However, with the current implementation of perl.h it cannot be any better because it defines macros like tTHX that are types for some implementations and empty for other (non-concurrent probably), and if I offload AddImageToRegistry to a static function I gain readability but I lose the warning (ironically) although the semantics did not change.
Cure:
Code: Select all
do
{
assert (image);
clone=CloneImage(image,0,0,MagickTrue,exception);
if ((clone == (Image *) NULL) || (exception->severity >= ErrorException))
goto PerlException;
TransformImage(&clone,crop_geometry,geometry);
do
{
register SV *sv;
assert (clone);
assert (magick_registry);
AddImageToRegistry(clone);
rv=newRV(sv);
av_push(av,sv_bless(rv,hv));
SvREFCNT_dec(sv);
} while (0 + (clone = clone -> next));
} while (0 + (image = image -> next));