Dereferencing pointer does break strict anti-aliasing rules using Berkeley sockets

c compiler-warnings berkeley-sockets
Nantucket picture Nantucket · Aug 12, 2010 · Viewed 10.3k times · Source

I've got code that looks something like this, where addr is a sockaddr*:

struct sockaddr_in *sin = (struct sockaddr_in *) addr;
const char *IP=inet_ntoa(sin -> sin_addr);

I believe this is very typical code for using Berkeley sockets.

However, when I compile this, I'm getting the following warning:
dereferencing pointer 'sin' does break strict anti-aliasing rules

Searching online, I find some discussion of the fact that the way I'm doing things is pretty typical, but this compiler warning also is pretty real and not a good thing.

What's the proper way to redo this code to fix the warning, and not just silence it?

Answer

tloach picture tloach · Aug 20, 2013

I had the same issue - it looks like a bug in gcc.

I was able to get around it by using

(*sin).sin_addr

instead of

sin->sin_addr

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