Re: Properly controlling CFLAGS/CXXFLAGS

Garrett Cooper wrote:
[...]
Interesting. No wonder I didn't have it in my Gentoo /etc/make.conf. It appears (from what I see) that maybe -fno-strict-aliasing has been enabled by default (at least it doesn't show up in the GCC 4.1.1 manpage on FC5).

It's documented in GCC's info page. There, you may want to search for '-fstrict-aliasing' instead of '-fno-strict-aliasing'. The 'no-' prefix is generic and can be used to switch off flags that are on by default or have been set to on earlier in the command line.

With '-O2' and better, '-fstrict-aliasing' is the default in newer versions of GCC, AFAIK, but people tend to switch it off because it apparently breaks too many software packages. Or at least those whose code base dates back to times where '-fno-strict-aliasing' was the default and people got away with certain nasty coding hacks that no longer work with '-fstrict-aliasing'.

Uwe
--
Uwe Doering | EscapeBox - Managed On-Demand UNIX Servers
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