On Tue, 20 May 2014, Jan Hubicka wrote: > Hi, > as disucssed some time ago, our assumption that every symbol of shared > library can > be interposed at runtime is expensive and prevents a lot of useful > optimizations, > including inlining or IPA propagation. > > While this is useful feature, it is rather incommon to use it for bigger C++ > projects, like firefox and at least clang seems to ignore the ELF > interposition > rules and always inline/propagate. This patch adds flag to control the > behaviour. > Symbols explicitly delcared WEAK are still considered as interposable.
I could see a use for an option listing the symbols that can be interposed. (For example, glibc supports interposition of a limited number of malloc-related symbols, but if it were made to support building with LTO in future that it would make sense to be able to optimize calls to most other functions.) -- Joseph S. Myers jos...@codesourcery.com
