Bug#440408: [x86,x64] tests argument instead of return value, fails to compile xmlrpc-c with optimization

[Falk Hueffner <falk@debian.org>]

"Nemui Ailin" <ailin.nemui@gmail.com> writes:

> Compiling xmlrpc-c CVS from <URL:http://xmlrpc-c.sourceforge.net/>
> results in a broken xmlrpc library that fails to allocate memory for the
> structs.
>
> We have this call to realloc in src/method.c
>
> 	static __inline__ void
> 	reallocProduct(void **      const blockP,
> 						unsigned int const factor1,
> 						unsigned int const factor2) {
> 		
> 		 if (UINT_MAX / factor2 < factor1)
> 			  *blockP = NULL;
> 		 else
> 			  *blockP = realloc(*blockP, factor1 * factor2);
> 	}
>
> 	#define REALLOCARRAY(arrayName, nElements) \
> 		 reallocProduct((void **)&arrayName, nElements, sizeof(arrayName[0]))
>
> 	REALLOCARRAY(signatureP->argList, minArgCount);
> 	if (signatureP->argList == NULL) {
> 	// ...

Unfortunately, you did not send a complete test case, so this is hard
to tell, but it looks like an aliasing violation in your code.
"*blockP" accesses an lvalue of type "void*", while its actual type is
probably some other pointer type; that is not allowed.

Please test whether the problem goes away with -fno-strict-aliasing.
If not, please provide a complete test case.

-- 
	Falk