Don't put library-supplied -L/-I switches before user-supplied ones.

For many optional libraries, we extract the -L and -l switches needed
to link the library from a helper program such as llvm-config.  In
some cases we put the resulting -L switches into LDFLAGS ahead of
-L switches specified via --with-libraries.  That risks breaking
the user's intention for --with-libraries.

It's not such a problem if the library's -L switch points to a
directory containing only that library, but on some platforms a
library helper may "helpfully" offer a switch such as -L/usr/lib
that points to a directory holding all standard libraries.  If the
user specified --with-libraries in hopes of overriding the standard
build of some library, the -L/usr/lib switch prevents that from
happening since it will come before the user-specified directory.

To fix, avoid inserting these switches directly into LDFLAGS during
configure, instead adding them to LIBDIRS or SHLIB_LINK.  They will
still eventually get added to LDFLAGS, but only after the switches
coming from --with-libraries.

The same problem exists for -I switches: those coming from
--with-includes should appear before any coming from helper programs
such as llvm-config.  We have not heard field complaints about this
case, but it seems certain that a user attempting to override a
standard library could have issues.

The changes for this go well beyond configure itself, however,
because many Makefiles have occasion to manipulate CPPFLAGS to
insert locally-desirable -I switches, and some of them got it wrong.
The correct ordering is any -I switches pointing at within-the-
source-tree-or-build-tree directories, then those from the tree-wide
CPPFLAGS, then those from helper programs.  There were several places
that risked pulling in a system-supplied copy of libpq headers, for
example, instead of the in-tree files.  (Commit cb36f8ec2 fixed one
instance of that a few months ago, but this exercise found more.)

The Meson build scripts may or may not have any comparable problems,
but I'll leave it to someone else to investigate that.

Reported-by: Charles Samborski <demurgos@demurgos.net>
Author: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://postgr.es/m/70f2155f-27ca-4534-b33d-7750e20633d7@demurgos.net
Backpatch-through: 13

diff --git a/config/llvm.m4 b/config/llvm.m4
index 21d8cd4f90f97a120820f9008daf8cd1eaa0a598..93fa9e070e89d8d551ba8ea1d3737bc1e34d3d69 100644 (file)
--- a/config/llvm.m4
+++ b/config/llvm.m4
@@ -4,7 +4,7 @@
 # -----------------
 #
 # Look for the LLVM installation, check that it's new enough, set the
-# corresponding LLVM_{CFLAGS,CXXFLAGS,BINPATH} and LDFLAGS
+# corresponding LLVM_{CFLAGS,CXXFLAGS,BINPATH,LIBS}
 # variables. Also verify that CLANG is available, to transform C
 # into bitcode.
 #
@@ -55,7 +55,7 @@ AC_DEFUN([PGAC_LLVM_SUPPORT],
 
   for pgac_option in `$LLVM_CONFIG --ldflags`; do
     case $pgac_option in
-      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+      -L*) LLVM_LIBS="$LLVM_LIBS $pgac_option";;
     esac
   done
 

diff --git a/configure b/configure
index eb05eaa227d9a63453d5c6048c83638f306412fd..361c01fd52375ac15a07106c0f28685875b994a9 100755 (executable)
--- a/configure
+++ b/configure
@@ -5207,7 +5207,7 @@ fi
 
   for pgac_option in `$LLVM_CONFIG --ldflags`; do
     case $pgac_option in
-      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+      -L*) LLVM_LIBS="$LLVM_LIBS $pgac_option";;
     esac
   done
 
@@ -9332,12 +9332,12 @@ fi
   # Note the user could also set XML2_CFLAGS/XML2_LIBS directly
   for pgac_option in $XML2_CFLAGS; do
     case $pgac_option in
-      -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
+      -I*|-D*) INCLUDES="$INCLUDES $pgac_option";;
     esac
   done
   for pgac_option in $XML2_LIBS; do
     case $pgac_option in
-      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+      -L*) LIBDIRS="$LIBDIRS $pgac_option";;
     esac
   done
 fi
@@ -9562,12 +9562,12 @@ fi
   # note that -llz4 will be added by AC_CHECK_LIB below.
   for pgac_option in $LZ4_CFLAGS; do
     case $pgac_option in
-      -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
+      -I*|-D*) INCLUDES="$INCLUDES $pgac_option";;
     esac
   done
   for pgac_option in $LZ4_LIBS; do
     case $pgac_option in
-      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+      -L*) LIBDIRS="$LIBDIRS $pgac_option";;
     esac
   done
 fi
@@ -9703,12 +9703,12 @@ fi
   # note that -lzstd will be added by AC_CHECK_LIB below.
   for pgac_option in $ZSTD_CFLAGS; do
     case $pgac_option in
-      -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
+      -I*|-D*) INCLUDES="$INCLUDES $pgac_option";;
     esac
   done
   for pgac_option in $ZSTD_LIBS; do
     case $pgac_option in
-      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+      -L*) LIBDIRS="$LIBDIRS $pgac_option";;
     esac
   done
 fi
@@ -16721,7 +16721,7 @@ fi
 
 if test "$with_icu" = yes; then
   ac_save_CPPFLAGS=$CPPFLAGS
-  CPPFLAGS="$ICU_CFLAGS $CPPFLAGS"
+  CPPFLAGS="$CPPFLAGS $ICU_CFLAGS"
 
   # Verify we have ICU's header files
   ac_fn_c_check_header_mongrel "$LINENO" "unicode/ucol.h" "ac_cv_header_unicode_ucol_h" "$ac_includes_default"
@@ -18876,7 +18876,7 @@ Use --without-tcl to disable building PL/Tcl." "$LINENO" 5
     fi
     # now that we have TCL_INCLUDE_SPEC, we can check for <tcl.h>
     ac_save_CPPFLAGS=$CPPFLAGS
-    CPPFLAGS="$TCL_INCLUDE_SPEC $CPPFLAGS"
+    CPPFLAGS="$CPPFLAGS $TCL_INCLUDE_SPEC"
     ac_fn_c_check_header_mongrel "$LINENO" "tcl.h" "ac_cv_header_tcl_h" "$ac_includes_default"
 if test "x$ac_cv_header_tcl_h" = xyes; then :
 
@@ -18945,7 +18945,7 @@ fi
 # check for <Python.h>
 if test "$with_python" = yes; then
   ac_save_CPPFLAGS=$CPPFLAGS
-  CPPFLAGS="$python_includespec $CPPFLAGS"
+  CPPFLAGS="$CPPFLAGS $python_includespec"
   ac_fn_c_check_header_mongrel "$LINENO" "Python.h" "ac_cv_header_Python_h" "$ac_includes_default"
 if test "x$ac_cv_header_Python_h" = xyes; then :
 

diff --git a/configure.ac b/configure.ac
index ca75eb00f5e81b83a8619120a0e784e9033f8db9..a870f98c10123d704a1e3c3ff8575d83af06702b 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1071,12 +1071,12 @@ if test "$with_libxml" = yes ; then
   # Note the user could also set XML2_CFLAGS/XML2_LIBS directly
   for pgac_option in $XML2_CFLAGS; do
     case $pgac_option in
-      -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
+      -I*|-D*) INCLUDES="$INCLUDES $pgac_option";;
     esac
   done
   for pgac_option in $XML2_LIBS; do
     case $pgac_option in
-      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+      -L*) LIBDIRS="$LIBDIRS $pgac_option";;
     esac
   done
 fi
@@ -1120,12 +1120,12 @@ if test "$with_lz4" = yes; then
   # note that -llz4 will be added by AC_CHECK_LIB below.
   for pgac_option in $LZ4_CFLAGS; do
     case $pgac_option in
-      -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
+      -I*|-D*) INCLUDES="$INCLUDES $pgac_option";;
     esac
   done
   for pgac_option in $LZ4_LIBS; do
     case $pgac_option in
-      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+      -L*) LIBDIRS="$LIBDIRS $pgac_option";;
     esac
   done
 fi
@@ -1145,12 +1145,12 @@ if test "$with_zstd" = yes; then
   # note that -lzstd will be added by AC_CHECK_LIB below.
   for pgac_option in $ZSTD_CFLAGS; do
     case $pgac_option in
-      -I*|-D*) CPPFLAGS="$CPPFLAGS $pgac_option";;
+      -I*|-D*) INCLUDES="$INCLUDES $pgac_option";;
     esac
   done
   for pgac_option in $ZSTD_LIBS; do
     case $pgac_option in
-      -L*) LDFLAGS="$LDFLAGS $pgac_option";;
+      -L*) LIBDIRS="$LIBDIRS $pgac_option";;
     esac
   done
 fi
@@ -1949,7 +1949,7 @@ fi
 
 if test "$with_icu" = yes; then
   ac_save_CPPFLAGS=$CPPFLAGS
-  CPPFLAGS="$ICU_CFLAGS $CPPFLAGS"
+  CPPFLAGS="$CPPFLAGS $ICU_CFLAGS"
 
   # Verify we have ICU's header files
   AC_CHECK_HEADER(unicode/ucol.h, [],
@@ -2298,7 +2298,7 @@ Use --without-tcl to disable building PL/Tcl.])
     fi
     # now that we have TCL_INCLUDE_SPEC, we can check for <tcl.h>
     ac_save_CPPFLAGS=$CPPFLAGS
-    CPPFLAGS="$TCL_INCLUDE_SPEC $CPPFLAGS"
+    CPPFLAGS="$CPPFLAGS $TCL_INCLUDE_SPEC"
     AC_CHECK_HEADER(tcl.h, [], [AC_MSG_ERROR([header file <tcl.h> is required for Tcl])])
     CPPFLAGS=$ac_save_CPPFLAGS
 fi
@@ -2335,7 +2335,7 @@ fi
 # check for <Python.h>
 if test "$with_python" = yes; then
   ac_save_CPPFLAGS=$CPPFLAGS
-  CPPFLAGS="$python_includespec $CPPFLAGS"
+  CPPFLAGS="$CPPFLAGS $python_includespec"
   AC_CHECK_HEADER(Python.h, [], [AC_MSG_ERROR([header file <Python.h> is required for Python])])
   CPPFLAGS=$ac_save_CPPFLAGS
 fi

diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index cc4dc6de91ea4b9e3ff4b34dabaf4b1027db34fa..ce05cc1429a22dbc8387895d1ad9ab65e21f1538 100644 (file)
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -240,7 +240,7 @@ CPP = @CPP@
 CPPFLAGS = @CPPFLAGS@
 PG_SYSROOT = @PG_SYSROOT@
 
-override CPPFLAGS := $(ICU_CFLAGS) $(CPPFLAGS)
+override CPPFLAGS += $(ICU_CFLAGS)
 
 ifdef PGXS
 override CPPFLAGS := -I$(includedir_server) -I$(includedir_internal) $(CPPFLAGS)

diff --git a/src/backend/jit/llvm/Makefile b/src/backend/jit/llvm/Makefile
index 607d16754f5a9e510ef330ec05704ade27a1f0a6..6fe96e7b9c7adce59d3cf8ddb8b17032d74793b8 100644 (file)
--- a/src/backend/jit/llvm/Makefile
+++ b/src/backend/jit/llvm/Makefile
@@ -31,7 +31,7 @@ endif
 # All files in this directory use LLVM.
 CFLAGS += $(LLVM_CFLAGS)
 CXXFLAGS += $(LLVM_CXXFLAGS)
-override CPPFLAGS := $(LLVM_CPPFLAGS) $(CPPFLAGS)
+override CPPFLAGS += $(LLVM_CPPFLAGS)
 SHLIB_LINK += $(LLVM_LIBS)
 
 # Because this module includes C++ files, we need to use a C++

diff --git a/src/bin/initdb/Makefile b/src/bin/initdb/Makefile
index d69bd89572ad7f6ccdb8408b26f1abf7c2dc286f..9e74e2a25a8488142b499b55a7bd9e4ef20c9e32 100644 (file)
--- a/src/bin/initdb/Makefile
+++ b/src/bin/initdb/Makefile
@@ -16,7 +16,7 @@ subdir = src/bin/initdb
 top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
-override CPPFLAGS := -I$(libpq_srcdir) -I$(top_srcdir)/src/timezone $(ICU_CFLAGS) $(CPPFLAGS)
+override CPPFLAGS := -I$(libpq_srcdir) -I$(top_srcdir)/src/timezone $(CPPFLAGS) $(ICU_CFLAGS)
 
 # Note: it's important that we link to encnames.o from libpgcommon, not
 # from libpq, else we have risks of version skew if we run with a libpq

diff --git a/src/interfaces/libpq/Makefile b/src/interfaces/libpq/Makefile
index 0919d8f32f6968a26787c073105b45d955a8da33..5cf1d6400e66a80fd1be3efea03bde4636e195ef 100644 (file)
--- a/src/interfaces/libpq/Makefile
+++ b/src/interfaces/libpq/Makefile
@@ -22,7 +22,7 @@ NAME= pq
 SO_MAJOR_VERSION= 5
 SO_MINOR_VERSION= $(MAJORVERSION)
 
-override CPPFLAGS :=  -I$(srcdir) $(CPPFLAGS) -I$(top_builddir)/src/port -I$(top_srcdir)/src/port
+override CPPFLAGS := -I$(srcdir) -I$(top_builddir)/src/port -I$(top_srcdir)/src/port $(CPPFLAGS)
 ifneq ($(PORTNAME), win32)
 override CFLAGS += $(PTHREAD_CFLAGS)
 endif

diff --git a/src/pl/plpython/Makefile b/src/pl/plpython/Makefile
index bb264266bb1c5f17ddc29c061858cd6ce42b2c40..3a8955bd0be2ca054c19ae8ac359ecf56b2640c3 100644 (file)
--- a/src/pl/plpython/Makefile
+++ b/src/pl/plpython/Makefile
@@ -11,7 +11,7 @@ ifeq ($(PORTNAME), win32)
 override python_libspec =
 endif
 
-override CPPFLAGS := -I. -I$(srcdir) $(python_includespec) $(CPPFLAGS)
+override CPPFLAGS := -I. -I$(srcdir) $(CPPFLAGS) $(python_includespec)
 
 rpathdir = $(python_libdir)
 

diff --git a/src/pl/tcl/Makefile b/src/pl/tcl/Makefile
index 314f9b2eec90433738b3e8938c569e6ad581e0b5..fb9f20c3f89e2df100b2e756374bc5a4d6e3c843 100644 (file)
--- a/src/pl/tcl/Makefile
+++ b/src/pl/tcl/Makefile
@@ -11,7 +11,7 @@ top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
 
-override CPPFLAGS := -I. -I$(srcdir) $(TCL_INCLUDE_SPEC) $(CPPFLAGS)
+override CPPFLAGS := -I. -I$(srcdir) $(CPPFLAGS) $(TCL_INCLUDE_SPEC)
 
 # On Windows, we don't link directly with the Tcl library; see below
 ifneq ($(PORTNAME), win32)