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Re: oversensitive "use of cast expressions as lvalues isdeprecated"
- From: Falk Hueffner <hueffner at informatik dot uni-tuebingen dot de>
- To: Shaun Jackman <sjackman at telus dot net>
- Cc: gcc-help at gcc dot gnu dot org
- Date: Thu, 24 Jun 2004 18:05:10 +0200
- Subject: Re: oversensitive "use of cast expressions as lvalues isdeprecated"
- References: <firstname.lastname@example.org>
Shaun Jackman <email@example.com> writes:
> The following statement is the result of a macro expansion (hence
> all the extra parenthesis). gcc's giving me a new warning about
> using a casted lvalue. I don't see where there is a casted lvalue
> here. The rhs of the assigment is an rvalue, so I'll ignore
> that. port is casted, but it's an rvalue at this point. Once it's
> dereferenced it's an lvalue, but there's no further casting after
> that. What's gone wrong here?
> int port;
> const void* src;
> (*((volatile uint16_t*)(port)) = (*((uint16_t *) src)++));
The casted lvalue is ((uint16_t *) src). The increment operator needs
a proper lvalue.
By the way, accessing nonvolatile objects through a volatile object
pointer is dangerous. It might do what you want, but is not guaranteed