From: Aleksandar Rakic <[email protected]>
This patch introduces a new configure-time option --with-multi-buildlist
to allow fine-grained control over which multilib variants are built.
The option accepts a path to a file containing a list of multilib
directories to be included in the build. Each line in the file should
contain a single multilib directory name, matching those generated by
the compiler's --print-multi-lib output.
This mechanism is target-independent and enables users to reduce build
time and binary size by excluding unnecessary multilib variants. It is
especially useful for embedded targets with constrained environments or
vendor-specific requirements.
The option is propagated to both host and target configuration stages,
and used in config-ml.in and gcc/Makefile.in to filter the multilib
list.
Documentation for this feature is added to gcc/doc/install.texi.
* config-ml.in: Use with_multi_buildlist to build multidirs.
Skip configuration for subdir returned by
--print-multi-directory.
* configure: Regenerate.
* configure.ac: Source target-specific configuration fragment
for GCC. Pass through with_multi_buildlist to host and target.
gcc/
* Makefile.in: Add with_multi_buildlist for multilib
configuration control. Use with_multi_buildlist to filter
multilib directories in fixinc_list.
* configure: Regenerate.
* configure.ac: Restrict the installed fixedincludes multilibs.
* configure.tgt: New file.
* doc/install.texi: Add --with-multi-buildlist configure option
for multilib filtering.
* genmultilib: Remove error for reuse of nonexistent multilibs.
This change allows reuse rules to reference multilib variants
that are not currently built. This is useful in configurations
where the set of built multilibs is filtered via
--with-multi-buildlist. Previously, genmultilib would emit an
error and abort if a reuse rule referenced a multilib that was
not present. With this change, such rules are silently ignored,
enabling more flexible and vendor-specific reuse setups.
Cherry-picked 2b2481cc71284ad9db3dff60bd6cab2be678e87e
from https://github.com/MIPS/gcc
Signed-off-by: Robert Suchanek <[email protected]>
Signed-off-by: Chao-ying Fu <[email protected]>
Signed-off-by: Aleksandar Rakic <[email protected]>
---
config-ml.in | 25 ++++++++++++++++++++++++-
configure | 15 +++++++++++++++
configure.ac | 15 +++++++++++++++
gcc/Makefile.in | 16 ++++++++++++++++
gcc/configure | 8 ++++++--
gcc/configure.ac | 3 +++
gcc/configure.tgt | 20 ++++++++++++++++++++
gcc/doc/install.texi | 24 ++++++++++++++++++++++++
gcc/genmultilib | 3 ---
9 files changed, 123 insertions(+), 6 deletions(-)
create mode 100644 gcc/configure.tgt
diff --git a/config-ml.in b/config-ml.in
index 645cac822fd..450bd1c05fd 100644
--- a/config-ml.in
+++ b/config-ml.in
@@ -488,6 +488,23 @@ powerpc*-*-* | rs6000*-*-*)
;;
esac
+# Use a filtered multilib list if requested.
+
+if [ x$with_multi_buildlist != x ]; then
+ old_multidirs="${multidirs}"
+ if [ ! -f $with_multi_buildlist ]; then
+ echo "config-ml.in: Failed to find $with_multi_buildlist"
+ exit 1
+ fi
+ multidirs=""
+ for x in ${old_multidirs}; do
+ found=`grep "^${x}$" $with_multi_buildlist`
+ if [ -n "$found" ]; then
+ multidirs="${multidirs} ${x}"
+ fi
+ done
+fi
+
# Remove extraneous blanks from multidirs.
# Tests like `if [ -n "$multidirs" ]' require it.
multidirs=`echo "$multidirs" | sed -e 's/^[ ][ ]*//' -e 's/[ ][ ]*$//' -e 's/[
][ ]*/ /g'`
@@ -597,7 +614,8 @@ else
fi
if [ -z "${with_multisubdir}" ]; then
- ml_subdir=
+ ml_top_subdir=`${CC-gcc} --print-multi-directory 2>/dev/null`
+ ml_subdir=/$ml_top_subdir
ml_builddotdot=
: # ml_srcdotdot= # already set
else
@@ -676,6 +694,11 @@ if [ -n "${multidirs}" ] && [ -z "${ml_norecursion}" ];
then
for ml_dir in ${multidirs}; do
+ if [ "${ml_dir}" == "${ml_top_subdir}" ]; then
+ echo "Skipping configure in multilib subdir ${ml_dir}"
+ continue
+ fi
+
if [ "${ml_verbose}" = --verbose ]; then
echo "Running configure in multilib subdir ${ml_dir}"
echo "pwd: `${PWDCMD-pwd}`"
diff --git a/configure b/configure
index a2e86731b08..738fe645722 100755
--- a/configure
+++ b/configure
@@ -11338,6 +11338,21 @@ if test x${enable_multilib} = x ; then
target_configargs="--enable-multilib ${target_configargs}"
fi
+# Source target-specific configuration fragment for GCC
+if test -d ${srcdir}/gcc; then
+ . ${srcdir}/gcc/configure.tgt
+fi
+
+# Pass through with_multi_buildlist to host and target. 'gcc' needs it for the
+# fixed includes which are multilib'd and target libraries need it as they use
+# config-ml.in.
+if test x${with_multi_buildlist} != x ; then
+ target_configargs="--with-multi-buildlist=${with_multi_buildlist} \
+ ${target_configargs}"
+ host_configargs="--with-multi-buildlist=${with_multi_buildlist} \
+ ${host_configargs}"
+fi
+
# Pass --with-newlib if appropriate. Note that target_configdirs has
# changed from the earlier setting of with_newlib.
if test x${with_newlib} != xno && echo " ${target_configdirs} " | grep "
newlib " > /dev/null 2>&1 && test -d ${srcdir}/newlib ; then
diff --git a/configure.ac b/configure.ac
index 25419a1d2ab..1112598d1b9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -3577,6 +3577,21 @@ if test x${enable_multilib} = x ; then
target_configargs="--enable-multilib ${target_configargs}"
fi
+# Source target-specific configuration fragment for GCC
+if test -d ${srcdir}/gcc; then
+ . ${srcdir}/gcc/configure.tgt
+fi
+
+# Pass through with_multi_buildlist to host and target. 'gcc' needs it for the
+# fixed includes which are multilib'd and target libraries need it as they use
+# config-ml.in.
+if test x${with_multi_buildlist} != x ; then
+ target_configargs="--with-multi-buildlist=${with_multi_buildlist} \
+ ${target_configargs}"
+ host_configargs="--with-multi-buildlist=${with_multi_buildlist} \
+ ${host_configargs}"
+fi
+
# Pass --with-newlib if appropriate. Note that target_configdirs has
# changed from the earlier setting of with_newlib.
if test x${with_newlib} != xno && echo " ${target_configdirs} " | grep "
newlib " > /dev/null 2>&1 && test -d ${srcdir}/newlib ; then
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index e8b2a38c8b3..0e86776450b 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -642,6 +642,9 @@ else
endif
endif
+# Multilib control
+with_multi_buildlist = @with_multi_buildlist@
+
# ------------------------
# Installation directories
# ------------------------
@@ -3383,10 +3386,23 @@ fixinc_list: s-fixinc_list; @true
s-fixinc_list : $(GCC_PASSES)
# Build up a list of multilib directories and corresponding sysroot
# suffixes, in form sysroot;multilib.
+# Use a filtered multilib list if requested.
if $(GCC_FOR_TARGET) -print-sysroot-headers-suffix > /dev/null 2>&1;
then \
set -e; for ml in `$(GCC_FOR_TARGET) -print-multi-lib`; do \
multi_dir=`echo $${ml} | sed -e 's/;.*$$//'`; \
flags=`echo $${ml} | sed -e 's/^[^;]*;//' -e 's/@/ -/g'`; \
+ if [ x$(with_multi_buildlist) != x ]; then \
+ if [ ! -f $(with_multi_buildlist) ]; then \
+ echo "fixinc_list: Failed to find $(with_multi_buildlist)"; \
+ exit 1; \
+ fi; \
+ set +e; \
+ found=`grep "^$${multi_dir}$$" $(with_multi_buildlist)`; \
+ set -e; \
+ if [ -z "$$found" ]; then \
+ continue; \
+ fi; \
+ fi; \
sfx=`$(GCC_FOR_TARGET) $${flags} -print-sysroot-headers-suffix`; \
if [ "$${multi_dir}" = "." ]; \
then multi_dir=""; \
diff --git a/gcc/configure b/gcc/configure
index 150ab616414..1341e1cbd3f 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -853,6 +853,7 @@ enable_fixed_point
enable_decimal_float
DEFAULT_INSNEMIT_PARTITIONS
DEFAULT_MATCHPD_PARTITIONS
+with_multi_buildlist
with_float
with_cpu
enable_multiarch
@@ -7870,6 +7871,9 @@ $as_echo "$enable_multiarch$ma_msg_suffix" >&6; }
+# needed for restricting the fixedincludes multilibs that we install
+
+
# default stack clash protection guard size as power of twos in bytes.
# Please keep these in sync with params.def.
stk_clash_min=12
@@ -21454,7 +21458,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 21457 "configure"
+#line 21461 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
@@ -21560,7 +21564,7 @@ else
lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
lt_status=$lt_dlunknown
cat > conftest.$ac_ext <<_LT_EOF
-#line 21563 "configure"
+#line 21567 "configure"
#include "confdefs.h"
#if HAVE_DLFCN_H
diff --git a/gcc/configure.ac b/gcc/configure.ac
index bdb22d53e2c..ee98191411e 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -877,6 +877,9 @@ AC_MSG_RESULT($enable_multiarch$ma_msg_suffix)
AC_SUBST(with_cpu)
AC_SUBST(with_float)
+# needed for restricting the fixedincludes multilibs that we install
+AC_SUBST(with_multi_buildlist)
+
# default stack clash protection guard size as power of twos in bytes.
# Please keep these in sync with params.def.
stk_clash_min=12
diff --git a/gcc/configure.tgt b/gcc/configure.tgt
new file mode 100644
index 00000000000..2c570b87ded
--- /dev/null
+++ b/gcc/configure.tgt
@@ -0,0 +1,20 @@
+# -*- shell-script -*-
+# Copyright (C) 2025 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not see <http://www.gnu.org/licenses/>.
+
+# This is the target specific configuration file. This is invoked by the
+# autoconf generated configure script. Putting it in a separate shell file
+# lets us skip running autoconf when modifying target specific information.
+
diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 705440ffd33..25306481860 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -1509,6 +1509,30 @@ medlow code model; rv64ima with lp64 and medany code
model
rv64ima-lp64--;--cmodel=medlow,medany
@end smallexample
+@item --with-multi-buildlist=@var{file}
+Specify a file containing a list of multilib directories to build.
+
+Each line in the file should contain a single multilib directory name,
+as printed by @code{gcc --print-multi-lib}. Only the listed directories
+will be built and installed.
+
+This option is useful for reducing build time and binary size by
+excluding unnecessary multilib variants. It is especially beneficial
+for embedded targets or vendor-specific toolchains.
+
+Example file contents:
+
+@smallexample
+mips-r6-hard/lib
+mips-r6-soft/lib32
+mipsel-r6-hard/lib64
+@end smallexample
+
+This option is target-independent and can be used with any architecture
+that supports multilibs. It is passed to both host and target
+configuration stages and used during fixed includes installation and
+multilib directory generation.
+
@item --with-endian=@var{endians}
Specify what endians to use.
Currently only implemented for sh*-*-*.
diff --git a/gcc/genmultilib b/gcc/genmultilib
index 85b241cd72a..5df8148e031 100644
--- a/gcc/genmultilib
+++ b/gcc/genmultilib
@@ -500,9 +500,6 @@ for rrule in ${multilib_reuse}; do
echo "The rule ${rrule} contains an option absent from
MULTILIB_OPTIONS." >&2
exit 1
fi
- else
- echo "The rule ${rrule} is trying to reuse nonexistent multilib." >&2
- exit 1
fi
done
--
2.34.1
