From d445b413c6e2a7afeb77b9e30a1c9241edb1af53 Mon Sep 17 00:00:00 2001 From: Neil Conway Date: Thu, 5 May 2005 11:50:18 +0000 Subject: [PATCH] The issue has been raised in the past that our build system links each executable against the maximal set of libraries it might need. So for example, if one executable requires `libreadline', all executables are linked against it. The easiest fix is to make use of GNU ld's --as-needed flag, which ignores linker arguments that are not actually needed by the specified object files. The attached patch modifies configure to check for this flag (when using GNU ld), and if ld supports it, adds the flag to LDFLAGS (we need to do the check since only relatively recent versions of GNU ld support this capability). Currently only GNU ld is supported; I'm not aware of any other linkers that support this functionality. --- configure | 73 ++++++++++++++++++++++++++++++++++++++++++++++++---- configure.in | 30 ++++++++++++++++++--- 2 files changed, 94 insertions(+), 9 deletions(-) diff --git a/configure b/configure index b77ec52aa8..ba97253d47 100755 --- a/configure +++ b/configure @@ -3622,11 +3622,6 @@ rm -f conftest* CPPFLAGS="$CPPFLAGS $INCLUDES" LDFLAGS="$LDFLAGS $LIBDIRS" -{ echo "$as_me:$LINENO: using CPPFLAGS=$CPPFLAGS" >&5 -echo "$as_me: using CPPFLAGS=$CPPFLAGS" >&6;} -{ echo "$as_me:$LINENO: using LDFLAGS=$LDFLAGS" >&5 -echo "$as_me: using LDFLAGS=$LDFLAGS" >&6;} - for ac_prog in gawk mawk nawk awk @@ -3856,6 +3851,7 @@ with_gnu_ld=$ac_cv_prog_gnu_ld + case $host_os in sysv5*) echo "$as_me:$LINENO: checking whether ld -R works" >&5 echo $ECHO_N "checking whether ld -R works... $ECHO_C" >&6 @@ -3909,6 +3905,68 @@ echo "${ECHO_T}$pgac_cv_prog_ld_R" >&6 ld_R_works=$pgac_cv_prog_ld_R esac + +# To simplify the build system, we specify the maximal set of +# libraries to link against when building any executable. The linker +# on some platforms optionally allows unused link arguments to be +# elided from the resulting executable, so enable that capability if +# it exists. +# XXX: currently we only support GNU ld; do any other linkers support +# an equivalent feature? +if test "$with_gnu_ld"; then + echo "$as_me:$LINENO: checking whether ld --as-needed works" >&5 +echo $ECHO_N "checking whether ld --as-needed works... $ECHO_C" >&6 +if test "${pgac_cv_prog_ld_as_needed+set}" = set; then + echo $ECHO_N "(cached) $ECHO_C" >&6 +else + + pgac_save_LDFLAGS=$LDFLAGS; LDFLAGS="$LDFLAGS -Wl,--as-needed" + cat >conftest.$ac_ext <<_ACEOF +#line $LINENO "configure" +#include "confdefs.h" + +#ifdef F77_DUMMY_MAIN +# ifdef __cplusplus + extern "C" +# endif + int F77_DUMMY_MAIN() { return 1; } +#endif +int +main () +{ + + ; + return 0; +} +_ACEOF +rm -f conftest.$ac_objext conftest$ac_exeext +if { (eval echo "$as_me:$LINENO: \"$ac_link\"") >&5 + (eval $ac_link) 2>&5 + ac_status=$? + echo "$as_me:$LINENO: \$? = $ac_status" >&5 + (exit $ac_status); } && + { ac_try='test -s conftest$ac_exeext' + { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5 + (eval $ac_try) 2>&5 + ac_status=$? + echo "$as_me:$LINENO: \$? = $ac_status" >&5 + (exit $ac_status); }; }; then + pgac_cv_prog_ld_as_needed=yes +else + echo "$as_me: failed program was:" >&5 +cat conftest.$ac_ext >&5 +pgac_cv_prog_ld_as_needed=no +fi +rm -f conftest.$ac_objext conftest$ac_exeext conftest.$ac_ext + if test x"$pgac_cv_prog_ld_as_needed" = x"no"; then + LDFLAGS=$pgac_save_LDFLAGS + fi + +fi +echo "$as_me:$LINENO: result: $pgac_cv_prog_ld_as_needed" >&5 +echo "${ECHO_T}$pgac_cv_prog_ld_as_needed" >&6 +fi + if test -n "$ac_tool_prefix"; then # Extract the first word of "${ac_tool_prefix}ranlib", so it can be a program name with args. set dummy ${ac_tool_prefix}ranlib; ac_word=$2 @@ -4167,6 +4225,11 @@ echo "${ECHO_T}no" >&6 +{ echo "$as_me:$LINENO: using CPPFLAGS=$CPPFLAGS" >&5 +echo "$as_me: using CPPFLAGS=$CPPFLAGS" >&6;} +{ echo "$as_me:$LINENO: using LDFLAGS=$LDFLAGS" >&5 +echo "$as_me: using LDFLAGS=$LDFLAGS" >&6;} + for ac_prog in 'bison -y' do # Extract the first word of "$ac_prog", so it can be a program name with args. diff --git a/configure.in b/configure.in index d8da7cd4ff..39ed00a1ab 100644 --- a/configure.in +++ b/configure.in @@ -1,5 +1,5 @@ dnl Process this file with autoconf to produce a configure script. -dnl $PostgreSQL: pgsql/configure.in,v 1.407 2005/03/25 00:34:19 tgl Exp $ +dnl $PostgreSQL: pgsql/configure.in,v 1.408 2005/05/05 11:50:18 neilc Exp $ dnl dnl Developers, please strive to achieve this order: dnl @@ -539,9 +539,6 @@ AC_SUBST(ELF_SYS) CPPFLAGS="$CPPFLAGS $INCLUDES" LDFLAGS="$LDFLAGS $LIBDIRS" -AC_MSG_NOTICE([using CPPFLAGS=$CPPFLAGS]) -AC_MSG_NOTICE([using LDFLAGS=$LDFLAGS]) - AC_ARG_VAR(LDFLAGS_SL) AC_PROG_AWK @@ -550,6 +547,7 @@ AC_PROG_LN_S PGAC_PROG_LD AC_SUBST(LD) AC_SUBST(with_gnu_ld) + case $host_os in sysv5*) AC_CACHE_CHECK([whether ld -R works], [pgac_cv_prog_ld_R], [ @@ -560,11 +558,35 @@ case $host_os in sysv5*) ld_R_works=$pgac_cv_prog_ld_R AC_SUBST(ld_R_works) esac + +# To simplify the build system, we specify the maximal set of +# libraries to link against when building any executable. The linker +# on some platforms optionally allows unused link arguments to be +# elided from the resulting executable, so enable that capability if +# it exists. +# XXX: currently we only support GNU ld; do any other linkers support +# an equivalent feature? +if test "$with_gnu_ld"; then + AC_CACHE_CHECK([whether ld --as-needed works], [pgac_cv_prog_ld_as_needed], + [ + pgac_save_LDFLAGS=$LDFLAGS; LDFLAGS="$LDFLAGS -Wl,--as-needed" + AC_TRY_LINK([], [], + [pgac_cv_prog_ld_as_needed=yes], + [pgac_cv_prog_ld_as_needed=no]) + if test x"$pgac_cv_prog_ld_as_needed" = x"no"; then + LDFLAGS=$pgac_save_LDFLAGS + fi + ]) +fi + AC_PROG_RANLIB AC_CHECK_PROGS(LORDER, lorder) AC_PATH_PROG(TAR, tar) PGAC_CHECK_STRIP +AC_MSG_NOTICE([using CPPFLAGS=$CPPFLAGS]) +AC_MSG_NOTICE([using LDFLAGS=$LDFLAGS]) + AC_CHECK_PROGS(YACC, ['bison -y']) if test "$YACC"; then -- 2.40.0