So we should enable pic automatically when the embed SAPI is selected;
otherwise we are safe to go for non-pic, correct?

--Wez.

On Thu, 16 Sep 2004 14:07:42 +0200 (CEST), Sascha Schumann
sascha@schumann.cx wrote:

Something like this sounds right:

--enable-slow-pic Build a slower DSO that can be used to run multiple
concurrent Apache instances. You don't
need this unless
you know why you need it.

Which gets me thinking... how does this affect other SAPI (like CLI,
embed) and extensions?

 CLI is a binary (no DSO, no PIC).

 Embed should probably be always built as PIC as it is
 supposed to be embedded as a library component.

 - Sascha

Makes sense to me.

The point is that the current behaviour needs to be retained
for installations which would be negatively affected by your
patch.  Building non-PIC as default is ok, if a switch is
provided to build PIC.

Ah, gotcha. Any preference as to flag name? --disable-non-pic would be
an obvious choice, confusing double negative though.

There is already a --without-pic/--with-pic flag that just doesn't work.
I'd key it off of that.

It doesn't work because PHP prevents AC_PROG_LIBTOOL from interpreting
it by doing "unset with_pic".

So one solution would be to remove that hack and in the case where
--with-pic or --without-pic is passed to configure, never explicitly
specify a pic "preference" to the libtool script. And make the default
as if "--without-pic" was passed in the x86* whitelist.

Index: configure.in

RCS file: /repository/php-src/configure.in,v
retrieving revision 1.516
diff -u -r1.516 configure.in
--- configure.in 21 Jul 2004 23:02:28 -0000 1.516
+++ configure.in 16 Sep 2004 14:07:03 -0000
@@ -1,4 +1,4 @@
-dnl ## $Id: configure.in,v 1.516 2004/07/21 23:02:28 edink Exp $ -- sh --
+dnl ## $Id: configure.in,v 1.516 2004/07/21 23:02:28 edink Exp $ -- autoconf --
dnl ## Process this file with autoconf to produce a configure script.

divert(1)
@@ -222,6 +222,21 @@
CPPFLAGS="$CPPFLAGS -D_XPG_IV";;
esac

+# Disable PIC mode by default where it is known to be safe to do so,
+# to avoid the performance hit from the lost register
+AC_MSG_CHECKING([whether to force non-PIC code in shared modules])
+case $host_alias in
+i?86--linux|i?86--freebsd)

• if test "${with_pic+set}" != "set"; then

•   with_pic=no
  

•   AC_MSG_RESULT(yes)
  

• else

•   AC_MSG_RESULT(no)
  

• fi
• ;;
  +*) AC_MSG_RESULT(no) ;;
  +esac

dnl Include Zend and TSRM configurations.
dnl -------------------------------------------------------------------------
@@ -850,7 +865,6 @@

enable_shared=yes
enable_static=yes
-unset with_pic

case $php_build_target in
program|static)
@@ -861,7 +875,9 @@
;;
shared)
enable_static=no

• standard_libtool_flag=-prefer-pic

• if test "${with_pic+set}" != set; then

•    standard_libtool_flag='-prefer-pic'
  

• fi
  EXTRA_LDFLAGS="$EXTRA_LDFLAGS -avoid-version -module"
  ;;
  esac
  Index: acinclude.m4
  ===================================================================
  RCS file: /repository/php-src/acinclude.m4,v
  retrieving revision 1.273
  diff -u -r1.273 acinclude.m4
  --- acinclude.m4 12 Sep 2004 06:35:51 -0000 1.273
  +++ acinclude.m4 16 Sep 2004 14:07:03 -0000
  @@ -772,11 +772,16 @@
  php_cxx_post=' && echo > $[@]'
  php_lo=o

• if test "${with_pic+set}" = set; then

• shared_c_meta='$(COMMON_FLAGS) $(CFLAGS_CLEAN) $(EXTRA_CFLAGS)'

• shared_cxx_meta='$(COMMON_FLAGS) $(CXXFLAGS_CLEAN) $(EXTRA_CXXFLAGS)'

• else

• shared_c_meta='$(COMMON_FLAGS) $(CFLAGS_CLEAN) $(EXTRA_CFLAGS) -prefer-pic'

• shared_cxx_meta='$(COMMON_FLAGS) $(CXXFLAGS_CLEAN) $(EXTRA_CXXFLAGS) -prefer-pic'

• fi
  shared_c_pre='$(LIBTOOL) --mode=compile $(CC)'

• shared_c_meta='$(COMMON_FLAGS) $(CFLAGS_CLEAN) $(EXTRA_CFLAGS) -prefer-pic'
  shared_c_post=
  shared_cxx_pre='$(LIBTOOL) --mode=compile $(CXX)'
• shared_cxx_meta='$(COMMON_FLAGS) $(CXXFLAGS_CLEAN) $(EXTRA_CXXFLAGS) -prefer-pic'
  shared_cxx_post=
  shared_lo=lo

@@ -1158,12 +1163,15 @@
install_modules="install-modules"
PHP_MODULES="$PHP_MODULES $(phplibdir)/$1.la"
PHP_SUBST($2)

• if test ${with_pic+set} != set; then

• php_shared_picflag="-prefer-pic"
  

• fi
  cat >>Makefile.objects<<EOF
  $(phplibdir)/$1.la: $3/$1.la
  $(LIBTOOL) --mode=install cp $3/$1.la $(phplibdir)

$3/$1.la: $($2) $(translit($1,a-z_-,A-Z__)_SHARED_DEPENDENCIES)

• $(LIBTOOL) --mode=link ifelse($4,,[$(CC)],[$(CXX)]) $(COMMON_FLAGS) $(CFLAGS_CLEAN) $(EXTRA_CFLAGS) $(LDFLAGS) -o [$]@ -export-dynamic -avoid-version -prefer-pic -module -rpath $(phplibdir) $(EXTRA_LDFLAGS) $($2) $(translit($1,a-z_-,A-Z__)_SHARED_LIBADD)

• $(LIBTOOL) --mode=link ifelse($4,,[$(CC)],[$(CXX)]) $(COMMON_FLAGS) $(CFLAGS_CLEAN) $(EXTRA_CFLAGS) $(LDFLAGS) -o [$]@ -export-dynamic -avoid-version $php_shared_picflag -module -rpath $(phplibdir) $(EXTRA_LDFLAGS) $($2) $(translit($1,a-z_-,A-Z__)_SHARED_LIBADD)

EOF
])

There is already a --without-pic/--with-pic flag that just doesn't work.
I'd key it off of that.

It doesn't work because PHP prevents AC_PROG_LIBTOOL from interpreting
it by doing "unset with_pic".

So one solution would be to remove that hack and in the case where
--with-pic or --without-pic is passed to configure, never explicitly
specify a pic "preference" to the libtool script. And make the default
as if "--without-pic" was passed in the x86* whitelist.

Index: configure.in

RCS file: /repository/php-src/configure.in,v

Did we ever came to the conclusion whether we should put this patch into
CVS. AFAIK everybody agreed with it...

regards,
Derick

Derick Rethans
http://derickrethans.nl | http://ez.no | http://xdebug.org