Skip gdb ifunc tests on targets that don't support this feature.

2018-10-03  Sandra Loosemore  <sandra@codesourcery.com>

	* lib/gdb.exp (skip_ifunc_tests): New.
	* gdb.base/gnu-ifunc.exp: Skip if no ifunc support.  Handle
	other compile failures.
	* gdb.compile/compile-ifunc.exp: Skip if no ifunc support.

gdb/testsuite/ChangeLog

@@ -1,3 +1,10 @@
+2018-10-03  Sandra Loosemore  <sandra@codesourcery.com>
+
+	* lib/gdb.exp (skip_ifunc_tests): New.
+	* gdb.base/gnu-ifunc.exp: Skip if no ifunc support.  Handle
+	other compile failures.
+	* gdb.compile/compile-ifunc.exp: Skip if no ifunc support.
+
 2018-10-01  Simon Marchi  <simon.marchi@ericsson.com>
 
 	* gdb.arch/i386-avx512.exp: Fix setting of nr_regs based on

gdb/testsuite/gdb.base/gnu-ifunc.exp

@@ -17,6 +17,10 @@ if {[skip_shlib_tests]} {
     return 0
 }
 
+if {[skip_ifunc_tests]} {
+    return 0
+}
+
 standard_testfile .c
 set staticexecutable ${testfile}-static
 set staticbinfile [standard_output_file ${staticexecutable}]
@@ -365,9 +369,10 @@ proc misc_tests {resolver_attr resolver_debug final_debug} {
 foreach_with_prefix resolver_attr {0 1} {
     foreach_with_prefix resolver_debug {0 1} {
 	foreach_with_prefix final_debug {0 1} {
-	    build $resolver_attr $resolver_debug $final_debug
-	    misc_tests $resolver_attr $resolver_debug $final_debug
-	    set-break $resolver_attr $resolver_debug $final_debug
+	    if { [build $resolver_attr $resolver_debug $final_debug] != 0 } {
+		misc_tests $resolver_attr $resolver_debug $final_debug
+		set-break $resolver_attr $resolver_debug $final_debug
+	    }
 	}
     }
 }

gdb/testsuite/gdb.compile/compile-ifunc.exp

@@ -13,6 +13,10 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+if {[skip_ifunc_tests]} {
+    return 0
+}
+
 standard_testfile
 
 with_test_prefix "nodebug" {

gdb/testsuite/lib/gdb.exp

@@ -2893,6 +2893,20 @@ gdb_caching_proc has_int128_cxx {
     return [gdb_int128_helper c++]
 }
 
+# Return true if the IFUNC feature is unsupported.
+gdb_caching_proc skip_ifunc_tests {
+    if [gdb_can_simple_compile ifunc {
+	extern void f_ ();
+	typedef void F (void);
+	F* g (void) { return &f_; }
+	void f () __attribute__ ((ifunc ("g")));
+    } object] {
+	return 0
+    } else {
+	return 1
+    }
+}
+
 # Return whether we should skip tests for showing inlined functions in
 # backtraces.  Requires get_compiler_info and get_debug_format.