Re: Linker errors while creating a PostgreSQL C extension function.

[Dmitry Igrishin]

вс, 19 авг. 2018 г. в 17:54, Tom Lane <t...@sss.pgh.pa.us>:
>
> Dmitry Igrishin <dmit...@gmail.com> writes:
> > вс, 19 авг. 2018 г. в 16:20, TalGloz <glozman...@gmail.com>:
> >> I'll try it later when I'm home. Is there a reason that you are linking 
> >> like
> >> this
> >> $(CXX) -Wl,--no-undefined -shared -o seal_diff_cpp.so $(LDFLAGS) $(LDLIBS)
> >> seal_diff_cpp.o
> >> And not like this?
> >> $(CXX) -Wl,--no-undefined -shared -o seal_diff_cpp.so seal_diff_cpp.o
> >> $(LDFLAGS) $(LDLIBS)
>
> > If I recall correctly there were some problems with ordering arguments
> > of the linker that are specified upon calling g++.
>
> You're creating such problems, not solving them, if you put the library
> first.  Particularly with .a-style libraries, you *must* list the
> referencing .o file first, or the linker will deem the library
> unreferenced and unnecessary.
Ah, I thought just the opposite :-) ! Since I use CMake I forget this
subtlety. Thank you for pointing this out!