blob: 5e0484fbb40757b4b90c081882abf1b687c1968a [file] [log] [blame]
http://gcc.gnu.org/ml/gcc-patches/2008-10/msg00269.html
On glibc the libc.so carries a copy of the math function copysignl() but
on uClibc math functions like copysignl() live in libm. Since libgcc_s
contains unresolved symbols, any attempt to link against libgcc_s
without explicitely specifying -lm fails, resulting in a broken
bootstrap of the compiler.
Forward port to gcc 4.5.1 by Gustavo Zacarias <gustavo@zacarias.com.ar>
---
libgcc/Makefile.in | 4 +++-
libgcc/configure | 32 ++++++++++++++++++++++++++++++++
libgcc/configure.ac | 21 +++++++++++++++++++++
3 files changed, 56 insertions(+), 1 deletion(-)
Index: b/libgcc/Makefile.in
===================================================================
--- a/libgcc/Makefile.in
+++ b/libgcc/Makefile.in
@@ -42,6 +42,7 @@
enable_vtable_verify = @enable_vtable_verify@
enable_decimal_float = @enable_decimal_float@
fixed_point = @fixed_point@
+LIBGCC_LIBM = @LIBGCC_LIBM@
host_noncanonical = @host_noncanonical@
target_noncanonical = @target_noncanonical@
@@ -943,9 +944,10 @@
@multilib_dir@,$(MULTIDIR),$(subst \
@shlib_objs@,$(objects) libgcc.a,$(subst \
@shlib_base_name@,libgcc_s,$(subst \
+ @libgcc_libm@,$(LIBGCC_LIBM),$(subst \
@shlib_map_file@,$(mapfile),$(subst \
@shlib_slibdir_qual@,$(MULTIOSSUBDIR),$(subst \
- @shlib_slibdir@,$(shlib_slibdir),$(SHLIB_LINK))))))))
+ @shlib_slibdir@,$(shlib_slibdir),$(SHLIB_LINK)))))))))
libunwind$(SHLIB_EXT): $(libunwind-s-objects) $(extra-parts)
# @multilib_flags@ is still needed because this may use
Index: b/libgcc/configure
===================================================================
--- a/libgcc/configure
+++ b/libgcc/configure
@@ -564,6 +564,7 @@
tmake_file
sfp_machine_header
set_use_emutls
+LIBGCC_LIBM
set_have_cc_tls
vis_hide
fixed_point
@@ -4535,6 +4536,37 @@
fi
fi
+# On powerpc libgcc_s references copysignl which is a libm function but
+# glibc apparently also provides it via libc as opposed to uClibc where
+# it lives in libm.
+echo "$as_me:$LINENO: checking for library containing copysignl" >&5
+echo $ECHO_N "checking for library containing copysignl... $ECHO_C" >&6
+if test "${libgcc_cv_copysignl_lib+set}" = set; then
+ echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+
+ echo '#include <features.h>' > conftest.c
+ echo 'int the_libc = __UCLIBC__ + __powerpc__;' >> conftest.c
+ libgcc_cv_copysignl_lib="-lc"
+ if { ac_try='${CC-cc} -S conftest.c -o conftest.s 1>&5'
+ { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ echo "$as_me:$LINENO: \$? = $ac_status" >&5
+ (exit $ac_status); }; }
+ then
+ libgcc_cv_copysignl_lib="-lm"
+ fi
+ rm -f conftest.*
+
+fi
+echo "$as_me:$LINENO: result: $libgcc_cv_copysignl_lib" >&5
+echo "${ECHO_T}$libgcc_cv_copysignl_lib" >&6
+
+case /${libgcc_cv_copysignl_lib}/ in
+ /-lm/) LIBGCC_LIBM="$LIBGCC_LIBM -lm" ;;
+ *) LIBGCC_LIBM= ;;
+esac
# Conditionalize the makefile for this target machine.
tmake_file_=
Index: b/libgcc/configure.ac
===================================================================
--- a/libgcc/configure.ac
+++ b/libgcc/configure.ac
@@ -357,6 +357,27 @@
fi
AC_SUBST(set_have_cc_tls)
+# On powerpc libgcc_s references copysignl which is a libm function but
+# glibc apparently also provides it via libc as opposed to uClibc where
+# it lives in libm.
+AC_CACHE_CHECK
+ libgcc_cv_copysignl_lib,
+ echo '#include <features.h>' > conftest.c
+ echo 'int the_libc = __UCLIBC__ + __powerpc__;' >> conftest.c
+ libgcc_cv_copysignl_lib="-lc"
+ if AC_TRY_COMMAND(${CC-cc} -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD)
+ then
+ libgcc_cv_copysignl_lib="-lm"
+ fi
+ rm -f conftest.*
+ ])
+
+case /${libgcc_cv_copysignl_lib}/ in
+ /-lm/) LIBGCC_LIBM="$LIBGCC_LIBM -lm" ;;
+ *) LIBGCC_LIBM= ;;
+esac
+AC_SUBST(LIBGCC_LIBM)
+
# See if we have emulated thread-local storage.
GCC_CHECK_EMUTLS
set_use_emutls=