dnl
-dnl If GNU ld is in use, check to see if tricky linker opts can be used. If
-dnl the native linker is in use, all variables will be defined to something
-dnl safe (like an empty string).
-dnl
-dnl Defines:
-dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible
-dnl OPT_LDFLAGS='-Wl,-O1' if possible
-dnl LD (as a side effect of testing)
-dnl Sets:
-dnl with_gnu_ld
-dnl libat_ld_is_gold (possibly)
-dnl libat_gnu_ld_version (possibly)
-dnl
-dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
-dnl set libat_gnu_ld_version to 12345. Zeros cause problems.
-dnl
-AC_DEFUN([LIBAT_CHECK_LINKER_FEATURES], [
- # If we're not using GNU ld, then there's no point in even trying these
- # tests. Check for that first. We should have already tested for gld
- # by now (in libtool), but require it now just to be safe...
- test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
- test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
- AC_REQUIRE([AC_PROG_LD])
- AC_REQUIRE([AC_PROG_AWK])
-
- # The name set by libtool depends on the version of libtool. Shame on us
- # for depending on an impl detail, but c'est la vie. Older versions used
- # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
- # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
- # makes sense). We'll test with_gnu_ld everywhere else, so if that isn't
- # set (hence we're using an older libtool), then set it.
- if test x${with_gnu_ld+set} != xset; then
- if test x${ac_cv_prog_gnu_ld+set} != xset; then
- # We got through "ac_require(ac_prog_ld)" and still not set? Huh?
- with_gnu_ld=no
- else
- with_gnu_ld=$ac_cv_prog_gnu_ld
- fi
- fi
-
- # Start by getting the version number. I think the libtool test already
- # does some of this, but throws away the result.
- libat_ld_is_gold=no
- if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
- libat_ld_is_gold=yes
- fi
- changequote(,)
- ldver=`$LD --version 2>/dev/null |
- sed -e 's/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\1/; q'`
- changequote([,])
- libat_gnu_ld_version=`echo $ldver | \
- $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
-
- # Set --gc-sections.
- if test "$with_gnu_ld" = "notbroken"; then
- # GNU ld it is! Joy and bunny rabbits!
-
- # All these tests are for C++; save the language and the compiler flags.
- # Need to do this so that g++ won't try to link in libstdc++
- ac_test_CFLAGS="${CFLAGS+set}"
- ac_save_CFLAGS="$CFLAGS"
- CFLAGS='-x c++ -Wl,--gc-sections'
-
- # Check for -Wl,--gc-sections
- # XXX This test is broken at the moment, as symbols required for linking
- # are now in libsupc++ (not built yet). In addition, this test has
- # cored on solaris in the past. In addition, --gc-sections doesn't
- # really work at the moment (keeps on discarding used sections, first
- # .eh_frame and now some of the glibc sections for iconv).
- # Bzzzzt. Thanks for playing, maybe next time.
- AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
- AC_TRY_RUN([
- int main(void)
- {
- try { throw 1; }
- catch (...) { };
- return 0;
- }
- ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
- if test "$ac_test_CFLAGS" = set; then
- CFLAGS="$ac_save_CFLAGS"
- else
- # this is the suspicious part
- CFLAGS=''
- fi
- if test "$ac_sectionLDflags" = "yes"; then
- SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
- fi
- AC_MSG_RESULT($ac_sectionLDflags)
- fi
-
- # Set linker optimization flags.
- if test x"$with_gnu_ld" = x"yes"; then
- OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
- fi
-
- AC_SUBST(SECTION_LDFLAGS)
- AC_SUBST(OPT_LDFLAGS)
-])
-
-
-dnl
dnl Add version tags to symbols in shared library (or not), additionally
dnl marking other symbols as private/local (or not).
dnl
projects / platform / upstream / gcc.git / commitdiff