Re: Rethinking -L switch handling and construction of LDFLAGS

So here's a draft patch for this.  It fixes the originally complained-of
issue about --with-libxml breaking the build on Macs.  I've not tested
it very far beyond that plus a sanity cross-check on Linux, but I doubt
there's any point in further manual testing; we might as well just
throw it at the buildfarm.

I'm pretty happy with the way this turned out.  It's not a complicated
change, and we're no longer breaking our own rules about how to manage
LDFLAGS adjustments.

Some notes:

* I ended up adding not only LDFLAGS_INTERNAL and SHLIB_LINK_INTERNAL,
but also PG_LIBS_INTERNAL.  As things stood, the only uses of PG_LIBS
were for within-tree library references, so that it was fine that the
make rule that uses this variable put it before LDFLAGS.  But if anyone
ever tried to use PG_LIBS for the seemingly obvious purpose of referencing
an external library, we'd be right back in hazard land.  So that variable
needs to be split as well.

* I documented SHLIB_LINK_INTERNAL and PG_LIBS_INTERNAL in the comments
in pgxs.mk, but not in the user-facing documentation about using PGXS.
This is on the theory that only within-tree modules need either of those
variables, so users don't need them.  I could be convinced otherwise,
though.

* Some of these changes aren't really essential, eg the change in
hstore_plperl/Makefile to use SHLIB_LINK_INTERNAL instead of SHLIB_LINK;
since there's no -L switch there, it'd work either way.  But I thought
it best to maintain a consistent rule of using the _INTERNAL variable
for within-tree references.

* The change to STD_LDFLAGS in src/common/Makefile is because I noticed
that "pg_config --ldflags" has been printing "-L../../../src/common",
which it surely should not.  Apparently we forgot to fix this rule when
we rearranged things to create src/common/.  I'm tempted to make the
rule be

STD_LDFLAGS := $(filter-out $(LDFLAGS_INTERNAL),$(LDFLAGS))

in hopes of preventing a repetition of such silliness, but desisted
for the moment, because I'm not quite sure if this is a good idea,
or if it risks taking too much out.  Anybody have an opinion about it?

            regards, tom lane

diff --git a/contrib/dblink/Makefile b/contrib/dblink/Makefile
index 5189758..b1a5e06 100644
--- a/contrib/dblink/Makefile
+++ b/contrib/dblink/Makefile
@@ -3,7 +3,7 @@
 MODULE_big = dblink
 OBJS    = dblink.o $(WIN32RES)
 PG_CPPFLAGS = -I$(libpq_srcdir)
-SHLIB_LINK = $(libpq)
+SHLIB_LINK_INTERNAL = $(libpq)

 EXTENSION = dblink
 DATA = dblink--1.2.sql dblink--1.1--1.2.sql dblink--1.0--1.1.sql \
diff --git a/contrib/hstore_plperl/Makefile b/contrib/hstore_plperl/Makefile
index c0906db..f63cba2 100644
--- a/contrib/hstore_plperl/Makefile
+++ b/contrib/hstore_plperl/Makefile
@@ -28,7 +28,7 @@ ifeq ($(PORTNAME), win32)
 # these settings are the same as for plperl
 override CPPFLAGS += -DPLPERL_HAVE_UID_GID -Wno-comment
 # ... see silliness in plperl Makefile ...
-SHLIB_LINK += $(sort $(wildcard ../../src/pl/plperl/libperl*.a))
+SHLIB_LINK_INTERNAL += $(sort $(wildcard ../../src/pl/plperl/libperl*.a))
 else
 rpathdir = $(perl_archlibexp)/CORE
 SHLIB_LINK += $(perl_embed_ldflags)
diff --git a/contrib/hstore_plpython/Makefile b/contrib/hstore_plpython/Makefile
index 7ff787a..b81735a 100644
--- a/contrib/hstore_plpython/Makefile
+++ b/contrib/hstore_plpython/Makefile
@@ -26,7 +26,7 @@ endif
 # We must link libpython explicitly
 ifeq ($(PORTNAME), win32)
 # ... see silliness in plpython Makefile ...
-SHLIB_LINK += $(sort $(wildcard ../../src/pl/plpython/libpython*.a))
+SHLIB_LINK_INTERNAL += $(sort $(wildcard ../../src/pl/plpython/libpython*.a))
 else
 rpathdir = $(python_libdir)
 SHLIB_LINK += $(python_libspec) $(python_additional_libs)
diff --git a/contrib/jsonb_plpython/Makefile b/contrib/jsonb_plpython/Makefile
index 8c7090a..b3c98e6 100644
--- a/contrib/jsonb_plpython/Makefile
+++ b/contrib/jsonb_plpython/Makefile
@@ -26,7 +26,7 @@ endif
 # We must link libpython explicitly
 ifeq ($(PORTNAME), win32)
 # ... see silliness in plpython Makefile ...
-SHLIB_LINK += $(sort $(wildcard ../../src/pl/plpython/libpython*.a))
+SHLIB_LINK_INTERNAL += $(sort $(wildcard ../../src/pl/plpython/libpython*.a))
 else
 rpathdir = $(python_libdir)
 SHLIB_LINK += $(python_libspec) $(python_additional_libs)
diff --git a/contrib/ltree_plpython/Makefile b/contrib/ltree_plpython/Makefile
index bc7502b..7e988c7 100644
--- a/contrib/ltree_plpython/Makefile
+++ b/contrib/ltree_plpython/Makefile
@@ -26,7 +26,7 @@ endif
 # We must link libpython explicitly
 ifeq ($(PORTNAME), win32)
 # ... see silliness in plpython Makefile ...
-SHLIB_LINK += $(sort $(wildcard ../../src/pl/plpython/libpython*.a))
+SHLIB_LINK_INTERNAL += $(sort $(wildcard ../../src/pl/plpython/libpython*.a))
 else
 rpathdir = $(python_libdir)
 SHLIB_LINK += $(python_libspec) $(python_additional_libs)
diff --git a/contrib/oid2name/Makefile b/contrib/oid2name/Makefile
index 3414b4a..3eef8f6 100644
--- a/contrib/oid2name/Makefile
+++ b/contrib/oid2name/Makefile
@@ -7,7 +7,7 @@ PROGRAM = oid2name
 OBJS    = oid2name.o $(WIN32RES)

 PG_CPPFLAGS = -I$(libpq_srcdir)
-PG_LIBS = $(libpq_pgport)
+PG_LIBS_INTERNAL = $(libpq_pgport)

 ifdef USE_PGXS
 PG_CONFIG = pg_config
diff --git a/contrib/postgres_fdw/Makefile b/contrib/postgres_fdw/Makefile
index 3543312..85394b4 100644
--- a/contrib/postgres_fdw/Makefile
+++ b/contrib/postgres_fdw/Makefile
@@ -5,7 +5,7 @@ OBJS = postgres_fdw.o option.o deparse.o connection.o shippable.o $(WIN32RES)
 PGFILEDESC = "postgres_fdw - foreign data wrapper for PostgreSQL"

 PG_CPPFLAGS = -I$(libpq_srcdir)
-SHLIB_LINK = $(libpq)
+SHLIB_LINK_INTERNAL = $(libpq)

 EXTENSION = postgres_fdw
 DATA = postgres_fdw--1.0.sql
diff --git a/contrib/spi/Makefile b/contrib/spi/Makefile
index 10ab5bb..42aa374 100644
--- a/contrib/spi/Makefile
+++ b/contrib/spi/Makefile
@@ -17,8 +17,6 @@ DOCS = $(addsuffix .example, $(MODULES))
 # comment out if you want a quieter refint package for other uses
 PG_CPPFLAGS = -DREFINT_VERBOSE

-LDFLAGS_SL += -L$(top_builddir)/src/port -lpgport
-
 ifdef USE_PGXS
 PG_CONFIG = pg_config
 PGXS := $(shell $(PG_CONFIG) --pgxs)
diff --git a/contrib/vacuumlo/Makefile b/contrib/vacuumlo/Makefile
index b4ba896..71106ff 100644
--- a/contrib/vacuumlo/Makefile
+++ b/contrib/vacuumlo/Makefile
@@ -7,7 +7,7 @@ PROGRAM = vacuumlo
 OBJS    = vacuumlo.o $(WIN32RES)

 PG_CPPFLAGS = -I$(libpq_srcdir)
-PG_LIBS = $(libpq_pgport)
+PG_LIBS_INTERNAL = $(libpq_pgport)

 ifdef USE_PGXS
 PG_CONFIG = pg_config
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 04cace1..2dac3ff 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -290,17 +290,26 @@ LLVM_LIBS=@LLVM_LIBS@
 LD = @LD@
 with_gnu_ld = @with_gnu_ld@

-# We want -L for libpgport.a and libpgcommon.a to be first in LDFLAGS.  We
-# also need LDFLAGS to be a "recursively expanded" variable, else adjustments
-# to rpathdir don't work right.  So we must NOT do LDFLAGS := something,
-# meaning this has to be done first and elsewhere we must only do LDFLAGS +=
-# something.
+# It's critical that within LDFLAGS, all -L switches pointing to build-tree
+# directories come before any -L switches pointing to external directories.
+# Otherwise it's possible for, e.g., a platform-provided copy of libpq.so
+# to get linked in place of the one we've built.  Therefore we adopt the
+# convention that the first component of LDFLAGS is an extra variable
+# LDFLAGS_INTERNAL, and -L and -l switches for PG's own libraries must be
+# put into LDFLAGS_INTERNAL, so they will appear ahead of those for external
+# libraries.
+#
+# We need LDFLAGS and LDFLAGS_INTERNAL to be "recursively expanded" variables,
+# else adjustments to, e.g., rpathdir don't work right.  So we must NOT do
+# "LDFLAGS := something" anywhere, ditto for LDFLAGS_INTERNAL.
+# These initial assignments must be "=" type, and elsewhere we must only do
+# "LDFLAGS += something" or "LDFLAGS_INTERNAL += something".
 ifdef PGXS
-  LDFLAGS = -L$(libdir)
+  LDFLAGS_INTERNAL = -L$(libdir)
 else
-  LDFLAGS = -L$(top_builddir)/src/port -L$(top_builddir)/src/common
+  LDFLAGS_INTERNAL = -L$(top_builddir)/src/port -L$(top_builddir)/src/common
 endif
-LDFLAGS += @LDFLAGS@
+LDFLAGS = $(LDFLAGS_INTERNAL) @LDFLAGS@

 LDFLAGS_EX = @LDFLAGS_EX@
 # LDFLAGS_SL might have already been assigned by calling makefile
diff --git a/src/Makefile.shlib b/src/Makefile.shlib
index 74d48c5..95b82a6 100644
--- a/src/Makefile.shlib
+++ b/src/Makefile.shlib
@@ -20,12 +20,16 @@
 #
 # NAME                  Name of library to build (no suffix nor "lib" prefix)
 # OBJS                  List of object files to include in library
-# SHLIB_LINK            If shared library relies on other libraries,
-#                       additional stuff to put in its link command
+# SHLIB_LINK            Stuff to append to library's link command
+#                       (typically, -L and -l switches for external libraries)
+# SHLIB_LINK_INTERNAL   -L and -l switches for Postgres-supplied libraries
 # SHLIB_PREREQS         Order-only prerequisites for library build target
 # SHLIB_EXPORTS         (optional) Name of file containing list of symbols to
 #                       export, in the format "function_name  number"
 #
+# Don't use SHLIB_LINK for references to files in the build tree, or the
+# wrong things will happen --- use SHLIB_LINK_INTERNAL for those!
+#
 # When building a shared library, the following version information
 # must also be set.  It should be omitted when building a dynamically
 # loadable module.
@@ -70,6 +74,8 @@
 COMPILER = $(CC) $(CFLAGS)
 LINK.static = $(AR) $(AROPT)

+LDFLAGS_INTERNAL += $(SHLIB_LINK_INTERNAL)
+


 ifdef SO_MAJOR_VERSION
diff --git a/src/backend/replication/libpqwalreceiver/Makefile b/src/backend/replication/libpqwalreceiver/Makefile
index a7a5fe1..75b0e2b 100644
--- a/src/backend/replication/libpqwalreceiver/Makefile
+++ b/src/backend/replication/libpqwalreceiver/Makefile
@@ -15,7 +15,8 @@ include $(top_builddir)/src/Makefile.global
 override CPPFLAGS := -I$(srcdir) -I$(libpq_srcdir) $(CPPFLAGS)

 OBJS = libpqwalreceiver.o $(WIN32RES)
-SHLIB_LINK = $(libpq) $(filter -lintl, $(LIBS))
+SHLIB_LINK_INTERNAL = $(libpq)
+SHLIB_LINK = $(filter -lintl, $(LIBS))
 SHLIB_PREREQS = submake-libpq
 PGFILEDESC = "libpqwalreceiver - receive WAL during streaming replication"
 NAME = libpqwalreceiver
diff --git a/src/bin/initdb/Makefile b/src/bin/initdb/Makefile
index dae3daf..8c23941 100644
--- a/src/bin/initdb/Makefile
+++ b/src/bin/initdb/Makefile
@@ -19,7 +19,7 @@ include $(top_builddir)/src/Makefile.global
 override CPPFLAGS := -DFRONTEND -I$(libpq_srcdir) -I$(top_srcdir)/src/timezone $(CPPFLAGS)

 # note: we need libpq only because fe_utils does
-override LDFLAGS := -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport)

 # use system timezone data?
 ifneq (,$(with_system_tzdata))
diff --git a/src/bin/pg_basebackup/Makefile b/src/bin/pg_basebackup/Makefile
index 54f915e..74dfb7a 100644
--- a/src/bin/pg_basebackup/Makefile
+++ b/src/bin/pg_basebackup/Makefile
@@ -19,7 +19,7 @@ top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global

 override CPPFLAGS := -I$(libpq_srcdir) $(CPPFLAGS)
-override LDFLAGS := -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport)

 OBJS=receivelog.o streamutil.o walmethods.o $(WIN32RES)

diff --git a/src/bin/pg_ctl/Makefile b/src/bin/pg_ctl/Makefile
index 4afc791..0202853 100644
--- a/src/bin/pg_ctl/Makefile
+++ b/src/bin/pg_ctl/Makefile
@@ -20,7 +20,7 @@ include $(top_builddir)/src/Makefile.global
 # but let's not pull that in on platforms where we don't need it.
 ifeq ($(PORTNAME), win32)
 override CPPFLAGS := -I$(libpq_srcdir) $(CPPFLAGS)
-override LDFLAGS := $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += $(libpq_pgport)
 SUBMAKE_LIBPQ := submake-libpq
 endif

diff --git a/src/bin/pg_dump/Makefile b/src/bin/pg_dump/Makefile
index e3bfc95..c46804a 100644
--- a/src/bin/pg_dump/Makefile
+++ b/src/bin/pg_dump/Makefile
@@ -17,7 +17,7 @@ top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global

 override CPPFLAGS := -I$(libpq_srcdir) $(CPPFLAGS)
-override LDFLAGS := -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport)

 OBJS=    pg_backup_archiver.o pg_backup_db.o pg_backup_custom.o \
     pg_backup_null.o pg_backup_tar.o pg_backup_directory.o \
diff --git a/src/bin/pg_rewind/Makefile b/src/bin/pg_rewind/Makefile
index 422c3ee..2bcfcc6 100644
--- a/src/bin/pg_rewind/Makefile
+++ b/src/bin/pg_rewind/Makefile
@@ -16,7 +16,7 @@ top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global

 override CPPFLAGS := -I$(libpq_srcdir) -DFRONTEND $(CPPFLAGS)
-override LDFLAGS := $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += $(libpq_pgport)

 OBJS    = pg_rewind.o parsexlog.o xlogreader.o datapagemap.o timeline.o \
     fetch.o file_ops.o copy_fetch.o libpq_fetch.o filemap.o logging.o \
diff --git a/src/bin/pg_upgrade/Makefile b/src/bin/pg_upgrade/Makefile
index 1d6ee70..adb0d5d 100644
--- a/src/bin/pg_upgrade/Makefile
+++ b/src/bin/pg_upgrade/Makefile
@@ -12,7 +12,7 @@ OBJS = check.o controldata.o dump.o exec.o file.o function.o info.o \
        tablespace.o util.o version.o $(WIN32RES)

 override CPPFLAGS := -DDLSUFFIX=\"$(DLSUFFIX)\" -I$(srcdir) -I$(libpq_srcdir) $(CPPFLAGS)
-override LDFLAGS := -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport)


 all: pg_upgrade
diff --git a/src/bin/pgbench/Makefile b/src/bin/pgbench/Makefile
index 8a8e516..25abd0a 100644
--- a/src/bin/pgbench/Makefile
+++ b/src/bin/pgbench/Makefile
@@ -10,7 +10,7 @@ include $(top_builddir)/src/Makefile.global
 OBJS = pgbench.o exprparse.o $(WIN32RES)

 override CPPFLAGS := -I. -I$(srcdir) -I$(libpq_srcdir) $(CPPFLAGS)
-override LDFLAGS := -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport)

 ifneq ($(PORTNAME), win32)
 override CFLAGS += $(PTHREAD_CFLAGS)
diff --git a/src/bin/psql/Makefile b/src/bin/psql/Makefile
index 2ad73d0..cd1b1b6 100644
--- a/src/bin/psql/Makefile
+++ b/src/bin/psql/Makefile
@@ -19,7 +19,7 @@ include $(top_builddir)/src/Makefile.global
 REFDOCDIR= $(top_srcdir)/doc/src/sgml/ref

 override CPPFLAGS := -I. -I$(srcdir) -I$(libpq_srcdir) $(CPPFLAGS)
-override LDFLAGS := -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport)

 OBJS=    command.o common.o copy.o crosstabview.o \
     describe.o help.o input.o large_obj.o mainloop.o \
diff --git a/src/bin/scripts/Makefile b/src/bin/scripts/Makefile
index 0cc528e..4c6e4b9 100644
--- a/src/bin/scripts/Makefile
+++ b/src/bin/scripts/Makefile
@@ -19,7 +19,7 @@ include $(top_builddir)/src/Makefile.global
 PROGRAMS = createdb createuser dropdb dropuser clusterdb vacuumdb reindexdb pg_isready

 override CPPFLAGS := -I$(libpq_srcdir) $(CPPFLAGS)
-override LDFLAGS := -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += -L$(top_builddir)/src/fe_utils -lpgfeutils $(libpq_pgport)

 all: $(PROGRAMS)

diff --git a/src/common/Makefile b/src/common/Makefile
index 80e78d7..9bbd86d 100644
--- a/src/common/Makefile
+++ b/src/common/Makefile
@@ -29,7 +29,7 @@ LIBS += $(PTHREAD_LIBS)

 # don't include subdirectory-path-dependent -I and -L switches
 STD_CPPFLAGS := $(filter-out -I$(top_srcdir)/src/include -I$(top_builddir)/src/include,$(CPPFLAGS))
-STD_LDFLAGS := $(filter-out -L$(top_builddir)/src/port,$(LDFLAGS))
+STD_LDFLAGS := $(filter-out -L$(top_builddir)/src/common -L$(top_builddir)/src/port,$(LDFLAGS))
 override CPPFLAGS += -DVAL_CONFIGURE="\"$(configure_args)\""
 override CPPFLAGS += -DVAL_CC="\"$(CC)\""
 override CPPFLAGS += -DVAL_CPPFLAGS="\"$(STD_CPPFLAGS)\""
diff --git a/src/interfaces/ecpg/compatlib/Makefile b/src/interfaces/ecpg/compatlib/Makefile
index cd03af5..ebfd895 100644
--- a/src/interfaces/ecpg/compatlib/Makefile
+++ b/src/interfaces/ecpg/compatlib/Makefile
@@ -22,8 +22,8 @@ override CPPFLAGS := -I../include -I$(top_srcdir)/src/interfaces/ecpg/include \
     -I$(libpq_srcdir) -DFRONTEND $(CPPFLAGS)
 override CFLAGS += $(PTHREAD_CFLAGS)

-SHLIB_LINK = -L../ecpglib -lecpg -L../pgtypeslib -lpgtypes $(libpq) \
-    $(filter -lintl -lm, $(LIBS)) $(PTHREAD_LIBS)
+SHLIB_LINK_INTERNAL = -L../ecpglib -lecpg -L../pgtypeslib -lpgtypes $(libpq)
+SHLIB_LINK = $(filter -lintl -lm, $(LIBS)) $(PTHREAD_LIBS)
 SHLIB_PREREQS = submake-ecpglib submake-pgtypeslib

 SHLIB_EXPORTS = exports.txt
diff --git a/src/interfaces/ecpg/ecpglib/Makefile b/src/interfaces/ecpg/ecpglib/Makefile
index bc20cf7..d25d248 100644
--- a/src/interfaces/ecpg/ecpglib/Makefile
+++ b/src/interfaces/ecpg/ecpglib/Makefile
@@ -35,7 +35,8 @@ ifneq ($(PORTNAME), win32)
 OBJS += thread.o
 endif

-SHLIB_LINK = -L../pgtypeslib -lpgtypes $(libpq) $(filter -lintl -lm, $(LIBS)) $(PTHREAD_LIBS)
+SHLIB_LINK_INTERNAL = -L../pgtypeslib -lpgtypes $(libpq)
+SHLIB_LINK = $(filter -lintl -lm, $(LIBS)) $(PTHREAD_LIBS)
 SHLIB_PREREQS = submake-libpq submake-pgtypeslib

 SHLIB_EXPORTS = exports.txt
diff --git a/src/interfaces/ecpg/pgtypeslib/Makefile b/src/interfaces/ecpg/pgtypeslib/Makefile
index 0945f3d..29264ce 100644
--- a/src/interfaces/ecpg/pgtypeslib/Makefile
+++ b/src/interfaces/ecpg/pgtypeslib/Makefile
@@ -25,7 +25,7 @@ override CFLAGS += $(PTHREAD_CFLAGS)
 # Need to recompile any libpgport object files
 LIBS := $(filter-out -lpgport, $(LIBS))

-SHLIB_LINK += -lm
+SHLIB_LINK += $(filter -lm, $(LIBS))

 SHLIB_EXPORTS = exports.txt

diff --git a/src/interfaces/ecpg/test/Makefile.regress b/src/interfaces/ecpg/test/Makefile.regress
index b3d7c1e..06c0461 100644
--- a/src/interfaces/ecpg/test/Makefile.regress
+++ b/src/interfaces/ecpg/test/Makefile.regress
@@ -5,8 +5,9 @@ override CPPFLAGS := -I../../include -I$(top_srcdir)/src/interfaces/ecpg/include
     -I$(libpq_srcdir) $(CPPFLAGS)
 override CFLAGS += $(PTHREAD_CFLAGS)

-override LDFLAGS := -L../../ecpglib -L../../pgtypeslib $(filter-out -l%, $(libpq)) $(LDFLAGS)
-override LIBS := -lecpg -lpgtypes $(filter -l%, $(libpq)) $(LIBS) $(PTHREAD_LIBS)
+LDFLAGS_INTERNAL += -L../../ecpglib -lecpg -L../../pgtypeslib -lpgtypes $(libpq)
+
+override LIBS += $(PTHREAD_LIBS)

 # Standard way to invoke the ecpg preprocessor
 ECPG = ../../preproc/ecpg --regression -I$(srcdir)/../../include -I$(srcdir)
diff --git a/src/interfaces/ecpg/test/compat_informix/Makefile b/src/interfaces/ecpg/test/compat_informix/Makefile
index 8a5e854..d50fdc2 100644
--- a/src/interfaces/ecpg/test/compat_informix/Makefile
+++ b/src/interfaces/ecpg/test/compat_informix/Makefile
@@ -6,8 +6,7 @@ include $(top_srcdir)/$(subdir)/../Makefile.regress
 # Use special informix compatibility switch for all tests in this directory
 ECPG += -C INFORMIX

-override LDFLAGS := -L../../compatlib $(LDFLAGS)
-override LIBS := -lecpg_compat $(LIBS)
+LDFLAGS_INTERNAL += -L../../compatlib -lecpg_compat

 TESTS = test_informix test_informix.c \
         test_informix2 test_informix2.c \
diff --git a/src/makefiles/pgxs.mk b/src/makefiles/pgxs.mk
index 5beb1e6..c038836 100644
--- a/src/makefiles/pgxs.mk
+++ b/src/makefiles/pgxs.mk
@@ -45,7 +45,9 @@
 #   EXTRA_CLEAN -- extra files to remove in 'make clean'
 #   PG_CPPFLAGS -- will be added to CPPFLAGS
 #   PG_LIBS -- will be added to PROGRAM link line
+#   PG_LIBS_INTERNAL -- same, for references to libraries within build tree
 #   SHLIB_LINK -- will be added to MODULE_big link line
+#   SHLIB_LINK_INTERNAL -- same, for references to libraries within build tree
 #   PG_CONFIG -- path to pg_config program for the PostgreSQL installation
 #     to build against (typically just "pg_config" to use the first one in
 #     your PATH)
@@ -315,5 +317,5 @@ endif

 ifdef PROGRAM
 $(PROGRAM): $(OBJS)
-    $(CC) $(CFLAGS) $(OBJS) $(PG_LIBS) $(LDFLAGS) $(LDFLAGS_EX) $(LIBS) -o $@$(X)
+    $(CC) $(CFLAGS) $(OBJS) $(PG_LIBS_INTERNAL) $(LDFLAGS) $(LDFLAGS_EX) $(PG_LIBS) $(LIBS) -o $@$(X)
 endif
diff --git a/src/tools/findoidjoins/Makefile b/src/tools/findoidjoins/Makefile
index a3462b9..1af0a93 100644
--- a/src/tools/findoidjoins/Makefile
+++ b/src/tools/findoidjoins/Makefile
@@ -13,7 +13,7 @@ top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global

 override CPPFLAGS := -I$(libpq_srcdir) $(CPPFLAGS)
-override LDFLAGS := $(libpq_pgport) $(LDFLAGS)
+LDFLAGS_INTERNAL += $(libpq_pgport)

 OBJS= findoidjoins.o