1src/port/README
2
3libpgport
4=========
5
6libpgport must have special behavior.  It supplies functions to both
7libraries and applications.  However, there are two complexities:
8
91)  Libraries need to use object files that are compiled with exactly
10the same flags as the library.  libpgport might not use the same flags,
11so it is necessary to recompile the object files for individual
12libraries.  This is done by removing -lpgport from the link line:
13
14        # Need to recompile any libpgport object files
15        LIBS := $(filter-out -lpgport, $(LIBS))
16
17and adding infrastructure to recompile the object files:
18
19        OBJS= execute.o typename.o descriptor.o data.o error.o prepare.o memory.o \
20                connect.o misc.o path.o exec.o \
21                $(filter strlcat.o, $(LIBOBJS))
22
23The problem is that there is no testing of which object files need to be
24added, but missing functions usually show up when linking user
25applications.
26
272) For applications, we use -lpgport before -lpq, so the static files
28from libpgport are linked first.  This avoids having applications
29dependent on symbols that are _used_ by libpq, but not intended to be
30exported by libpq.  libpq's libpgport usage changes over time, so such a
31dependency is a problem.  Windows, Linux, AIX, and macOS use an export
32list to control the symbols exported by libpq.
33