Bug in gcc?

Tim Cussins timcussins at eml.cc
Thu Jun 5 16:37:17 UTC 2008

Leon Pollak wrote:
> Hello, all.
> It seems to me I found a bug in gcc, but as it is rtems-provided cross-gcc, I 
> think it was better to ask here first.
> I have the following code:
> template <class TYPE> class sCmnd2DSPs {
> public:
> 	enum eSources {eDiscr=0, eRS1, eRS2, 
> 		eMB1, eMB2, eEth1, eEth2} __attribute__ ((packed));
> 	struct {
> 		eSources	Source;
> 		uchar		Addr;
> 		eCmndCodesDSPs	Opcode;
> 		TYPE		Params; } __attribute__ ((packed));
> ...............
> };
> Everything works fine, but the field Source in the code above occupies 4 
> bytes, despite the packed request.
> Now, if I take the enumeration declaration out of the class (put it above the 
> class declaration), then the Source field occupies 1 byte as required.
> Should I report this to gcc list?
> Thanks.

Before you do that you might want to check how it behaves on a normal
*nix machine - and also maybe have a look at how it behaves for a normal
(non-templated) class.

btw - if the enum is common to all classes based on that template, maybe
it should be outside the template definition anyway ;P


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