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 29f40977f3eed37fdd1dfdf9078bcc1b3e25262e..6a49431c0f261c5d6008443579f8ee9a68ec854d 100755 (executable)
--- a/configure
+++ b/configure
@@ -5147,7 +5147,7 @@ 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
 
@@ -9214,12 +9214,12 @@ 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
@@ -17034,7 +17034,7 @@ _ACEOF
 
 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"
@@ -19258,7 +19258,7 @@ 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 :
 
@@ -19327,7 +19327,7 @@ 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.in b/configure.in
index c17342b1ba0b31d1a726e2d5ae7265e925bf7d08..b2b573c9b86676a8af312985794e825a5f1f3bba 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -1047,12 +1047,12 @@ 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
@@ -1961,7 +1961,7 @@ AC_CHECK_DECLS([strtoll, strtoull])
 
 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, [],
@@ -2320,7 +2320,7 @@ 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
@@ -2357,7 +2357,7 @@ 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 b75bafd1148aa81e874e1e3e47edd201d43ac380..aca750ad933e237b8fad7b736fdd9b5fdca6fefc 100644 (file)
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -242,7 +242,7 @@ 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/interfaces/libpq/Makefile b/src/interfaces/libpq/Makefile
index d4919970f88868eeebcc38058f3f89ecd4bfc6fb..911f1f6d952ac64a2e8908069cce670ed576ef53 100644 (file)
--- a/src/interfaces/libpq/Makefile
+++ b/src/interfaces/libpq/Makefile
@@ -21,7 +21,7 @@ NAME= pq
 SO_MAJOR_VERSION= 5
 SO_MINOR_VERSION= $(MAJORVERSION)
 
-override CPPFLAGS :=  -DFRONTEND -DUNSAFE_STAT_OK -I$(srcdir) $(CPPFLAGS) -I$(top_builddir)/src/port -I$(top_srcdir)/src/port
+override CPPFLAGS := -DFRONTEND -DUNSAFE_STAT_OK -I$(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 35d828f864ae8cb22ef568f8ebc75911688c2da7..60d3f74d5174932ef7d0a5c38209974d5a19cbfc 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 25e65189b60be8f61b19bd340d9d0c742fa5723d..059daeffeaa0d8df7b450de814d29c253eb04d02 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)