Matthew Knepley <[email protected]> writes: > On Sun, Dec 31, 2017 at 2:35 PM, Jed Brown <[email protected]> wrote: > >> Matthew Knepley <[email protected]> writes: >> >> > On Sun, Dec 31, 2017 at 1:55 PM, Jed Brown <[email protected]> wrote: >> > >> >> These look like linker errors and that build uses >> >> --with-cxxlib-autodetect=0. We either need a rule to *link* C++ using >> >> CXX (i.e., mpicxx) or add LIBS=-lstdc++. >> >> >> > >> > I thought we were doing this (linking C++ mains with CXX). >> >> After compiling to the object file (ex3.o) we don't know what language >> main was written in, and this doesn't solve the actual problem that C++ >> linking is required if any object (not just main) depends on C++. >> > > My thinking here was the following: > > 1) No C++ is allowed in PETSc, unless --with-clanguage=cxx, in which case > the linker is C++ > 2) If C++ is in an external library, then that configure requires the C++ > library > 3) The executable itself could be C++, in which case I proposed using the > C++ linker explicitly > > About not knowing which objects come with C++ main: I thought we did. Don't > they go into a separate set?
Right, we do have that information for tests. Note that a single test executable can depend on multiple source files, and the one containing main might not be C++ while another is. I don't know if there are any such instances in PETSc. I can change the build rules for tests with C++ sources later today.
