https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61372
--- Comment #4 from Jonathan Wakely <redi at gcc dot gnu.org> --- (In reply to David Crocker from comment #3) > (In reply to Jonathan Wakely from comment #2) > > extern "C" functions can throw, so it would be wrong to unconditionally > > assume they can't. > > True, you can write an extern "C" function that throws. But does it ever > make sense to? I don't think so. Functions written in C and then declared > extern "C" in a C++ program so that they can be called from C++ won't throw > or propagate exceptions, That's not true. std::bsearch and std::qsort are counterexamples. You don't know what the user-provided function does, and you can't assume it doesn't throw. > even if they end up calling functions written in > C++ that throw. The only reason to write a function in C++ and declare it > extern "C" is so that it call be called from C, in which case it had better > not throw. That's an incorrect assumption. Not all extern "C" functions are written in C++. Even if they are, you can't assume they don't throw because they could use callbacks that can throw, or they might throw even in C programs (which works fine for some targets, unwinding the stack exactly as a C++ program wants it to). It would be OK to optionally assume functions with C language linkage don't throw, but it must be optional.
