Arrange to strip libpq.so of symbols that aren't officially supposed to

be exported on Linux and Darwin.  We already did this on Windows but
that's not enough, as evidenced by the fact that libecpg had an unexpected
dependency on one such symbol.  We should try to do it on more platforms.
Fix ecpg's oversight, and bump libpq's major .so version number to reflect
the unwanted but nonetheless real ABI break.

src/Makefile.shlib

@@ -6,7 +6,7 @@
 # Copyright (c) 1998, Regents of the University of California
 #
 # IDENTIFICATION
-#    $PostgreSQL: pgsql/src/Makefile.shlib,v 1.103 2006/04/19 16:32:08 tgl Exp $
+#    $PostgreSQL: pgsql/src/Makefile.shlib,v 1.104 2006/04/28 02:53:20 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -107,11 +107,11 @@ ifeq ($(PORTNAME), darwin)
   ifeq ($(DLTYPE), library)
     # linkable library
     DLSUFFIX		:= .dylib
-    LINK.shared		= $(COMPILER) -dynamiclib -install_name $(libdir)/lib$(NAME).$(SO_MAJOR_VERSION)$(DLSUFFIX) $(version_link) -multiply_defined suppress
+    LINK.shared		= $(COMPILER) -dynamiclib -install_name $(libdir)/lib$(NAME).$(SO_MAJOR_VERSION)$(DLSUFFIX) $(version_link) $(exported_symbols_list) -multiply_defined suppress
   else
     # loadable module (default case)
     DLSUFFIX		:= .so
-    LINK.shared		= $(COMPILER) -bundle
+    LINK.shared		= $(COMPILER) -bundle -multiply_defined suppress
   endif
   shlib			= lib$(NAME).$(SO_MAJOR_VERSION).$(SO_MINOR_VERSION)$(DLSUFFIX)
   shlib_major		= lib$(NAME).$(SO_MAJOR_VERSION)$(DLSUFFIX)
@@ -186,7 +186,7 @@ ifeq ($(PORTNAME), irix)
 endif
 
 ifeq ($(PORTNAME), linux)
-  LINK.shared		= $(COMPILER) -shared -Wl,-soname,$(soname)
+  LINK.shared		= $(COMPILER) -shared -Wl,-soname,$(soname) $(exported_symbols_list)
 endif
 
 ifeq ($(PORTNAME), solaris)

src/interfaces/ecpg/ecpglib/Makefile

@@ -4,7 +4,7 @@
 #
 # Copyright (c) 1994, Regents of the University of California
 #
-# $PostgreSQL: pgsql/src/interfaces/ecpg/ecpglib/Makefile,v 1.38 2006/01/17 19:49:23 meskes Exp $
+# $PostgreSQL: pgsql/src/interfaces/ecpg/ecpglib/Makefile,v 1.39 2006/04/28 02:53:20 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -25,7 +25,7 @@ override CFLAGS += $(PTHREAD_CFLAGS)
 LIBS := $(filter-out -lpgport, $(LIBS))
 
 OBJS= execute.o typename.o descriptor.o data.o error.o prepare.o memory.o \
-	connect.o misc.o path.o exec.o \
+	connect.o misc.o path.o exec.o thread.o \
 	$(filter snprintf.o, $(LIBOBJS))
 
 SHLIB_LINK = -L../pgtypeslib -lpgtypes $(libpq) \
@@ -46,7 +46,7 @@ include $(top_srcdir)/src/Makefile.shlib
 # necessarily use the same object files as the backend uses. Instead,
 # symlink the source files in here and build our own object file.
 
-path.c exec.c snprintf.c: % : $(top_srcdir)/src/port/%
+path.c exec.c snprintf.c thread.c: % : $(top_srcdir)/src/port/%
 	rm -f $@ && $(LN_S) $< .
 
 path.o: path.c $(top_builddir)/src/port/pg_config_paths.h
@@ -62,7 +62,7 @@ installdirs:
 uninstall: uninstall-lib
 
 clean distclean maintainer-clean: clean-lib
-	rm -f $(OBJS) path.c exec.c snprintf.c
+	rm -f $(OBJS) path.c exec.c snprintf.c thread.c
 
 depend dep:
 	$(CC) -MM $(CFLAGS) *.c >depend

src/interfaces/libpq/Makefile

@@ -5,7 +5,7 @@
 # Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
 # Portions Copyright (c) 1994, Regents of the University of California
 #
-# $PostgreSQL: pgsql/src/interfaces/libpq/Makefile,v 1.143 2006/04/11 20:26:40 neilc Exp $
+# $PostgreSQL: pgsql/src/interfaces/libpq/Makefile,v 1.144 2006/04/28 02:53:20 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -16,8 +16,8 @@ include $(top_builddir)/src/Makefile.global
 
 # shared library parameters
 NAME= pq
-SO_MAJOR_VERSION= 4
-SO_MINOR_VERSION= 2
+SO_MAJOR_VERSION= 5
+SO_MINOR_VERSION= 0
 DLTYPE= library
 
 override CPPFLAGS :=  -DFRONTEND -I$(srcdir) $(CPPFLAGS) -I$(top_builddir)/src/port
@@ -125,6 +125,31 @@ $(srcdir)/blibpqdll.def: exports.txt
 	echo '; Aliases for MS compatible names' >> $@
 	sed -e '/^#/d' -e 's/^\(.* \)\([0-9][0-9]*\)/    \1= _\1/' < $< | sed 's/ *$$//' >> $@
 
+# Where possible, restrict the symbols exported by the library to just the
+# official list, so as to avoid unintentional ABI changes.  On recent Darwin
+# this also quiets multiply-defined-symbol warnings in programs that use
+# libpgport along with libpq.
+
+ifeq ($(PORTNAME), darwin)
+$(shlib): exports.list
+
+exports.list: exports.txt
+	$(AWK) '/^[^#]/ {printf "_%s\n",$$1}' $< >$@
+
+exported_symbols_list = -exported_symbols_list exports.list
+endif
+
+ifeq ($(PORTNAME), linux)
+$(shlib): exports.list
+
+exports.list: exports.txt
+	echo '{ global:' >$@
+	$(AWK) '/^[^#]/ {printf "%s;\n",$$1}' $< >>$@
+	echo ' local: *; };' >>$@
+
+exported_symbols_list = -Wl,--version-script=exports.list
+endif
+
 # depend on Makefile.global to force rebuild on re-run of configure
 $(srcdir)/libpq.rc: libpq.rc.in $(top_builddir)/src/Makefile.global
 	sed -e 's/\(VERSION.*\),0 *$$/\1,'`date '+%y%j' | sed 's/^0*//'`'/' < $< > $@
@@ -147,7 +172,7 @@ uninstall: uninstall-lib
 	rm -f '$(DESTDIR)$(includedir)/libpq-fe.h' '$(DESTDIR)$(includedir_internal)/libpq-int.h' '$(DESTDIR)$(includedir_internal)/pqexpbuffer.h' '$(DESTDIR)$(datadir)/pg_service.conf.sample'
 
 clean distclean: clean-lib
-	rm -f $(OBJS) pg_config_paths.h crypt.c getaddrinfo.c inet_aton.c noblock.c pgstrcasecmp.c snprintf.c strerror.c open.c thread.c md5.c ip.c encnames.c wchar.c pthread.h
+	rm -f $(OBJS) pg_config_paths.h crypt.c getaddrinfo.c inet_aton.c noblock.c pgstrcasecmp.c snprintf.c strerror.c open.c thread.c md5.c ip.c encnames.c wchar.c pthread.h exports.list
 	rm -f pg_config_paths.h	# Might be left over from a Win32 client-only build
 
 maintainer-clean: distclean