On Tue, Oct 18, 2011, Oleg Goldshmidt wrote about "Re: Newer gcc swallow
version control keywords":
> It was about C++. C and C++ compilers behave the same.
I was very surprised to discover that this is indeed the case. I think this
is a BUG. For example, consider this C++ program:
#include <cstdio>
class Ident {
public:
Ident(const char *ident){
// This constructor prints a message!
printf("yo\n");
}
};
static Ident id("$Id: hello $");
main(){
printf("hello\n");
}
If you compile it with g++ (without optimization), the object id gets
instanciated, and when you run the program you see the message "yo" first,
before "hello". But, if you compile it with g++ -O2, id gets optimized out
and its constructor never runs - and you never see the "yo" message.
So basically, compiling with -O2 changes the *behavior*, not just the
*performance*, of the code. I don't know how this cannot be called a bug?
But unfortunately, whether this is to be called a "bug" doesn't really
help you :(
--
Nadav Har'El | Tuesday, Oct 18 2011,
n...@math.technion.ac.il |-----------------------------------------
Phone +972-523-790466, ICQ 13349191 |This '|' is not a pipe.
http://nadav.harel.org.il |
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