re PR other/46840 (libgo should link against libm)

	PR other/46840
Link libgo against -lm.

From-SVN: r167582

libgo/Makefile.am

@@ -1267,7 +1267,7 @@ libgo_go_objs = \
 
 libgo_la_SOURCES = $(runtime_files)
 
-libgo_la_LIBADD = $(libgo_go_objs) $(LIBFFI) $(PTHREAD_LIBS)
+libgo_la_LIBADD = $(libgo_go_objs) $(LIBFFI) $(PTHREAD_LIBS) $(MATH_LIBS)
 
 libgobegin_a_SOURCES = \
 	runtime/go-main.c
@@ -1283,7 +1283,7 @@ LTGOCOMPILE = $(LIBTOOL) --tag GO --mode=compile $(GOC) $(INCLUDES) \
 
 GOLINK = $(LIBTOOL) --tag GO --mode-link $(GOC) \
 	$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_GOCFLAGS) $(LTLDFLAGS) \
-	$(PTHREAD_LIBS) -o $@
+	$(PTHREAD_LIBS) $(MATH_LIBS) -o $@
 
 # Build a package.
 BUILDARCHIVE = \

libgo/Makefile.in

@@ -121,7 +121,7 @@ libgobegin_a_OBJECTS = $(am_libgobegin_a_OBJECTS)
 LTLIBRARIES = $(toolexeclib_LTLIBRARIES)
 am__DEPENDENCIES_1 =
 libgo_la_DEPENDENCIES = $(libgo_go_objs) $(am__DEPENDENCIES_1) \
-	$(am__DEPENDENCIES_1)
+	$(am__DEPENDENCIES_1) $(am__DEPENDENCIES_1)
 am__libgo_la_SOURCES_DIST = runtime/go-append.c runtime/go-assert.c \
 	runtime/go-assert-interface.c \
 	runtime/go-byte-array-to-string.c runtime/go-breakpoint.c \
@@ -325,6 +325,7 @@ LN_S = @LN_S@
 LTLIBOBJS = @LTLIBOBJS@
 MAINT = @MAINT@
 MAKEINFO = @MAKEINFO@
+MATH_LIBS = @MATH_LIBS@
 MKDIR_P = @MKDIR_P@
 NM = @NM@
 NMEDIT = @NMEDIT@
@@ -1564,7 +1565,7 @@ libgo_go_objs = \
 	testing/libscript.la
 
 libgo_la_SOURCES = $(runtime_files)
-libgo_la_LIBADD = $(libgo_go_objs) $(LIBFFI) $(PTHREAD_LIBS)
+libgo_la_LIBADD = $(libgo_go_objs) $(LIBFFI) $(PTHREAD_LIBS) $(MATH_LIBS)
 libgobegin_a_SOURCES = \
 	runtime/go-main.c
 
@@ -1576,7 +1577,7 @@ LTGOCOMPILE = $(LIBTOOL) --tag GO --mode=compile $(GOC) $(INCLUDES) \
 
 GOLINK = $(LIBTOOL) --tag GO --mode-link $(GOC) \
 	$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_GOCFLAGS) $(LTLDFLAGS) \
-	$(PTHREAD_LIBS) -o $@
+	$(PTHREAD_LIBS) $(MATH_LIBS) -o $@
 
 
 # Build a package.

libgo/configure

@@ -607,6 +607,7 @@ HAVE_SYS_MMAN_H_FALSE
 HAVE_SYS_MMAN_H_TRUE
 PTHREAD_LIBS
 PTHREAD_CFLAGS
+MATH_LIBS
 USING_SPLIT_STACK_FALSE
 USING_SPLIT_STACK_TRUE
 SPLIT_STACK
@@ -10868,7 +10869,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10871 "configure"
+#line 10872 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -10974,7 +10975,7 @@ else
   lt_dlunknown=0; lt_dlno_uscore=1; lt_dlneed_uscore=2
   lt_status=$lt_dlunknown
   cat > conftest.$ac_ext <<_LT_EOF
-#line 10977 "configure"
+#line 10978 "configure"
 #include "confdefs.h"
 
 #if HAVE_DLFCN_H
@@ -13328,6 +13329,49 @@ $as_echo "#define LINKER_SUPPORTS_SPLIT_STACK 1" >>confdefs.h
 
 fi
 
+MATH_LIBS=
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for sqrt in -lm" >&5
+$as_echo_n "checking for sqrt in -lm... " >&6; }
+if test "${ac_cv_lib_m_sqrt+set}" = set; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lm  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char sqrt ();
+int
+main ()
+{
+return sqrt ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_m_sqrt=yes
+else
+  ac_cv_lib_m_sqrt=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_m_sqrt" >&5
+$as_echo "$ac_cv_lib_m_sqrt" >&6; }
+if test "x$ac_cv_lib_m_sqrt" = x""yes; then :
+  MATH_LIBS=-lm
+fi
+
+
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether -pthread is supported" >&5
 $as_echo_n "checking whether -pthread is supported... " >&6; }
 if test "${ac_cv_libgo_pthread_supported+set}" = set; then :

libgo/configure.ac

@@ -187,6 +187,11 @@ if test "$ac_cv_libgo_linker_supports_split_stack" = yes; then
 	    [Define if the linker support split stack adjustments])
 fi
 
+dnl Test for the -lm library.
+MATH_LIBS=
+AC_CHECK_LIB([m], [sqrt], MATH_LIBS=-lm)
+AC_SUBST(MATH_LIBS)
+
 dnl Test whether the compiler supports the -pthread option.
 AC_CACHE_CHECK([whether -pthread is supported],
 [ac_cv_libgo_pthread_supported],

libgo/testsuite/Makefile.in

@@ -101,6 +101,7 @@ LN_S = @LN_S@
 LTLIBOBJS = @LTLIBOBJS@
 MAINT = @MAINT@
 MAKEINFO = @MAKEINFO@
+MATH_LIBS = @MATH_LIBS@
 MKDIR_P = @MKDIR_P@
 NM = @NM@
 NMEDIT = @NMEDIT@