On Sun, 14 Oct 2007 12:18:09 -0700, Paul Pluzhnikov wrote: > skaller <[EMAIL PROTECTED]> writes: > >> So I have another (yes I tried to find the answer but haven't yet): how >> can I hook operator new()? > > This is very system-dependent. > Are you interested in Linux-only answer, or in gcc/any answer?
All platforms all compilers, incl. MSVC++ .. but just Linux/gcc will do for a start :) >> With malloc() we have __builtin_malloc which is a single global >> variable available to all shared libraries. > > Only on systems using glibc, and only when using dynamic linking. Really? Doesn't work for static links .. hmm. >> operator new() is a weak symbol in Elf isn't it? > > Not for any of my g++ versions: Then, how can one replace it? Because that definitely does work in a simple program. >> So it can be replaced by a user function globally? (even in by a shared >> library?) > > Weak here doesn't mean what you appear to think it means. > > Even though above symbols are all strong, they can still be interposed > by a user library, *provided* that library appears before libstdc++ in > runtime linker search list. To achive that, make sure your interposer is > before -lstdc++ on the link line. Well, -lstdc++ is never given on the link line, in fact, there's no link line since most people use gcc as the link driver. >> [Of course C++ Standard is quite stupid here. If you replace operator >> new, how do you call the original?] > > The "standard" Linux/Solaris technique is to use dlsym(RTLD_NEXT, ...) Which would only work with dynamic linkage. Hmm .. I seem to recall Boehm gc (which has to do all this somehow) uses a special file defining real_malloc() by calling malloc() .. and linking that before the code that defines malloc() by suballocating and sometimes calling real_malloc() .. ouch. -- John Skaller <skaller at users dot sf dot net> Try Felix, the successor to C++ http://felix.sf.net _______________________________________________ help-gplusplus mailing list help-gplusplus@gnu.org http://lists.gnu.org/mailman/listinfo/help-gplusplus
