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Re: add --enable-gnu-indirect-function configure switch
On 09/21/10 23:32, Joseph S. Myers wrote:
On Mon, 20 Sep 2010, Nathan Sidwell wrote:
This patch adds an explicit --enable-gnu-indirect-function configure switch,
Patches adding configure options need to update install.texi.
This patch is updated.
1) adds the above documentation
2) uses AS_HELP_STRING
3) copies the default_use_cxa_atexit idiom, so that we set the default value for
enable-gnu-indirect-function to no except for those targets we know should
support it (currently only x86-linux).
ok?
nathan
--
Nathan Sidwell :: http://www.codesourcery.com :: CodeSourcery
2010-09-26 Nathan Sidwell <nathan@codesourcery.com>
* configure.ac: Add --enable-indirect-function option.
* config.gcc: Add default_gnu_indirect_function.
* config.in (HAVE_GAS_INDIRECT_FUNCTION): Rename to ...
(HAVE_GNU_INDIRECT_FUNCTION): ... this.
* varasm.c (do_assemble_alias): Adjust for macto name change.
* configure: Rebuilt.
* doc/install.texi: Document --enable-indirect-function.
testsuite/
* lib/target-supports-dg.exp (dg-require-ifunc): Remove extraneous
alias checking.
* lib/target-supports.exp (check_ifunc_available): Likewise.
Index: doc/install.texi
===================================================================
--- doc/install.texi (revision 164584)
+++ doc/install.texi (working copy)
@@ -1229,6 +1229,10 @@
only available on systems with GNU libc. When enabled, this will cause
@option{-fuse-cxa-atexit} to be passed by default.
+@item --enable-indirect-function
+Define if you want to enable the ifunc attribute. This option is
+currently only available on systems with GNU libc on certain targets.
+
@item --enable-target-optspace
Specify that target
libraries should be optimized for code space instead of code speed.
Index: configure
===================================================================
--- configure (revision 164584)
+++ configure (working copy)
@@ -905,6 +905,7 @@
enable_fast_install
enable_libtool_lock
with_plugin_ld
+enable_gnu_indirect_function
enable_comdat
enable_gnu_unique_object
enable_linker_build_id
@@ -1611,6 +1612,9 @@
--enable-fast-install[=PKGS]
optimize for fast installation [default=yes]
--disable-libtool-lock avoid locking (might break parallel builds)
+ --enable-gnu-indirect-function
+ enable the use of the @gnu_indirect_function to
+ glibc systems
--enable-comdat enable COMDAT group support
--enable-gnu-unique-object enable the use of the @gnu_unique_object ELF extension on
glibc systems
@@ -17139,7 +17143,7 @@
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 17142 "configure"
+#line 17146 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -17245,7 +17249,7 @@
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 17248 "configure"
+#line 17252 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -21332,43 +21336,21 @@
# gnu_indirect_function type is an extension proposed at
# http://groups.google/com/group/generic-abi/files. It allows dynamic runtime
# selection of function implementation
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for gnu_indirect_function" >&5
-$as_echo_n "checking assembler for gnu_indirect_function... " >&6; }
-if test "${gcc_cv_as_indirect_function+set}" = set; then :
- $as_echo_n "(cached) " >&6
+# Check whether --enable-gnu-indirect-function was given.
+if test "${enable_gnu_indirect_function+set}" = set; then :
+ enableval=$enable_gnu_indirect_function; case $enable_gnu_indirect_function in
+ yes | no) ;;
+ *) as_fn_error "'$enable_gnu_indirect_function' is an invalid value for --enable-gnu-indirect-function.
+Valid choices are 'yes' and 'no'." "$LINENO" 5 ;;
+ esac
else
- gcc_cv_as_indirect_function=no
- if test $in_tree_gas = yes; then
- if test $in_tree_gas_is_elf = yes \
- && test $gcc_cv_gas_vers -ge `expr \( \( 2 \* 1000 \) + 20 \) \* 1000 + 1`
- then gcc_cv_as_indirect_function=yes
+ enable_gnu_indirect_function="$default_gnu_indirect_function"
fi
- elif test x$gcc_cv_as != x; then
- echo ' .type Foo, @gnu_indirect_function
-Foo:' > conftest.s
- if { ac_try='$gcc_cv_as $gcc_cv_as_flags -o conftest.o conftest.s >&5'
- { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
- (eval $ac_try) 2>&5
- ac_status=$?
- $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
- test $ac_status = 0; }; }
- then
- gcc_cv_as_indirect_function=yes
- else
- echo "configure: failed program was" >&5
- cat conftest.s >&5
- fi
- rm -f conftest.o conftest.s
- fi
-fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_indirect_function" >&5
-$as_echo "$gcc_cv_as_indirect_function" >&6; }
+if test x$enable_gnu_indirect_function = xyes; then
-if test $gcc_cv_as_indirect_function = yes ; then
+$as_echo "#define HAVE_GNU_INDIRECT_FUNCTION 1" >>confdefs.h
-$as_echo "#define HAVE_GAS_INDIRECT_FUNCTION 1" >>confdefs.h
-
fi
if test $in_tree_ld != yes ; then
Index: testsuite/lib/target-supports-dg.exp
===================================================================
--- testsuite/lib/target-supports-dg.exp (revision 164584)
+++ testsuite/lib/target-supports-dg.exp (working copy)
@@ -94,12 +94,7 @@
# test.
proc dg-require-ifunc { args } {
- set ifunc_available [ check_ifunc_available ]
- if { $ifunc_available == -1 } {
- upvar name name
- unresolved "$name"
- }
- if { $ifunc_available < 2 } {
+ if { ![ check_ifunc_available ] } {
upvar dg-do-what dg-do-what
set dg-do-what [list [lindex ${dg-do-what} 0] "N" "P"]
}
Index: testsuite/lib/target-supports.exp
===================================================================
--- testsuite/lib/target-supports.exp (revision 164584)
+++ testsuite/lib/target-supports.exp (working copy)
@@ -372,12 +372,10 @@
# proc check_ifunc_available { }
###############################
-# Determine if the target toolchain supports the alias attribute.
+# Determine if the target toolchain supports the ifunc attribute.
-# Returns 2 if the target supports aliases. Returns 1 if the target
-# only supports weak aliased. Returns 0 if the target does not
-# support aliases at all. Returns -1 if support for aliases could not
-# be determined.
+# Returns 1 if the target supports ifunc. Returns 0 if the target
+# does not support ifunc.
proc check_ifunc_available { } {
global ifunc_available_saved
@@ -390,26 +388,19 @@
set obj ifunc[pid].o
verbose "check_ifunc_available compiling testfile $src" 2
set f [open $src "w"]
- # Compile a small test program. The definition of "g" is
- # necessary to keep the Solaris assembler from complaining
- # about the program.
- puts $f "#ifdef __cplusplus\nextern \"C\"\n#endif\n"
- puts $f "void g() {} void f() __attribute__((ifunc(\"g\")));"
+ puts $f "#endif"
+ puts $f "#ifdef __cplusplus\nextern \"C\"\n#endif"
+ puts $f "void g() {}"
+ puts $f "void f() __attribute__((ifunc(\"g\")));"
close $f
set lines [${tool}_target_compile $src $obj object ""]
file delete $src
remote_file build delete $obj
if [string match "" $lines] then {
- # No error messages, everything is OK.
- set ifunc_available_saved 2
+ set ifunc_available_saved 1
} else {
- if [regexp "ifunc is not supported" $lines] {
- verbose "check_ifunc_available target does not support ifunc" 2
- set ifunc_available_saved 0
- } else {
- set ifunc_available_saved -1
- }
+ set ifunc_available_saved 0
}
verbose "check_ifunc_available returning $ifunc_available_saved" 2
Index: config.in
===================================================================
--- config.in (revision 164584)
+++ config.in (working copy)
@@ -968,8 +968,8 @@
/* Define if your assembler and linker support .hidden. */
#undef HAVE_GAS_HIDDEN
-/* Define if your assembler supports indirect function type. */
-#undef HAVE_GAS_INDIRECT_FUNCTION
+/* Define if your system supports gnu indirect functions. */
+#undef HAVE_GNU_INDIRECT_FUNCTION
/* Define if your assembler supports .lcomm with an alignment field. */
#ifndef USED_FOR_TARGET
Index: configure.ac
===================================================================
--- configure.ac (revision 164584)
+++ configure.ac (working copy)
@@ -2161,14 +2161,18 @@
# gnu_indirect_function type is an extension proposed at
# http://groups.google/com/group/generic-abi/files. It allows dynamic runtime
# selection of function implementation
-gcc_GAS_CHECK_FEATURE(gnu_indirect_function, gcc_cv_as_indirect_function,
- [elf,2,20,1],,
-[ .type Foo, @gnu_indirect_function
-Foo:])
-GCC_TARGET_TEMPLATE([HAVE_GAS_INDIRECT_FUNCTION])
-if test $gcc_cv_as_indirect_function = yes ; then
- AC_DEFINE(HAVE_GAS_INDIRECT_FUNCTION, 1,
- [Define if your assembler supports indirect function type.])
+AC_ARG_ENABLE(gnu-indirect-function,
+ [AS_HELP_STRING([--enable-gnu-indirect-function],
+ [enable the use of the @gnu_indirect_function to glibc systems])],
+ [case $enable_gnu_indirect_function in
+ yes | no) ;;
+ *) AC_MSG_ERROR(['$enable_gnu_indirect_function' is an invalid value for --enable-gnu-indirect-function.
+Valid choices are 'yes' and 'no'.]) ;;
+ esac],
+ [enable_gnu_indirect_function="$default_gnu_indirect_function"])
+if test x$enable_gnu_indirect_function = xyes; then
+ AC_DEFINE(HAVE_GNU_INDIRECT_FUNCTION, 1,
+ [Define if your system supports gnu indirect functions.])
fi
changequote(,)dnl
Index: varasm.c
===================================================================
--- varasm.c (revision 164584)
+++ varasm.c (working copy)
@@ -5357,7 +5357,7 @@
}
if (lookup_attribute ("ifunc", DECL_ATTRIBUTES (decl)))
{
-#if defined (ASM_OUTPUT_TYPE_DIRECTIVE) && HAVE_GAS_INDIRECT_FUNCTION
+#if defined (ASM_OUTPUT_TYPE_DIRECTIVE) && HAVE_GNU_INDIRECT_FUNCTION
ASM_OUTPUT_TYPE_DIRECTIVE
(asm_out_file, IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
IFUNC_ASM_TYPE);
Index: config.gcc
===================================================================
--- config.gcc (revision 164584)
+++ config.gcc (working copy)
@@ -45,6 +45,16 @@
# default value of $default_use_cxa_atexit is set to
# "no" except for targets which are known to be OK.
#
+# default_gnu_indirect_function
+# The default value for the $enable_gnu_indirect_function
+# variable. enable_gnu_indirect_function relies
+# upon the presence of a non-standard gnu ifunc support
+# in the assembler, linker and dynamic linker.
+# Since not all libraries provide the dynamic linking
+# support, the default value of
+# $default_gnu_indirect_function is set to
+# "no" except for targets which are known to be OK.
+#
# gas_flag Either yes or no depending on whether GNU as was
# requested.
#
@@ -205,6 +215,7 @@
gas="$gas_flag"
gnu_ld="$gnu_ld_flag"
default_use_cxa_atexit=no
+default_gnu_indirect_function=no
target_gtfiles=
need_64bit_hwint=
need_64bit_isa=
@@ -1192,6 +1203,8 @@
tm_file="${tm_file} i386/unix.h i386/att.h dbxelf.h elfos.h svr4.h linux.h glibc-stdint.h"
case ${target} in
i[34567]86-*-linux*)
+ # Assume modern glibc
+ default_gnu_indirect_function=yes
if test x$enable_targets = xall; then
tm_file="${tm_file} i386/x86-64.h i386/linux64.h"
tm_defines="${tm_defines} TARGET_BI_ARCH=1"
@@ -1227,6 +1240,8 @@
tm_file="${tm_file} i386/unix.h i386/att.h dbxelf.h elfos.h svr4.h linux.h glibc-stdint.h \
i386/x86-64.h i386/linux64.h"
case ${target} in
+ x86_64-*-linux*)
+ default_gnu_indirect_function=glibc-2011 ;;
x86_64-*-kfreebsd*-gnu) tm_file="${tm_file} kfreebsd-gnu.h" ;;
x86_64-*-knetbsd*-gnu) tm_file="${tm_file} knetbsd-gnu.h" ;;
esac