[PATCH, CHKP] Fix ipa-comdats for instrumentation thunks

[Ilya Enkovich <enkovich dot gnu at gmail dot com>]

Hi,

With r221574 (https://gcc.gnu.org/ml/gcc-cvs/2015-03/msg00495.html) thunks don't get comdat groups assigned and this causes a failure in cgraph checker for instrumentation thunks.  It happens because instrumentation thunk may reference local symbol in comdat not being in comdat by itself.  This patch fixes the problem.  Doesn't affect not instrumented code.  Testing is in progress.  Does it look OK?

Thanks,
Ilya
--
gcc/

2015-04-02  Ilya Enkovich  <ilya.enkovich@intel.com>

	* ipa-comdats.c (ipa_comdats): Visit all instrumentation
	thunks to set proper comdat group.

gcc/testsuite/

2015-04-02  Ilya Enkovich  <ilya.enkovich@intel.com>

	* gcc.target/i386/mpx/chkp-thunk-comdat-1.cc: New.
	* gcc.target/i386/mpx/chkp-thunk-comdat-2.cc: New.


diff --git a/gcc/ipa-comdats.c b/gcc/ipa-comdats.c
index f349f9f..30bcad8 100644
--- a/gcc/ipa-comdats.c
+++ b/gcc/ipa-comdats.c
@@ -348,10 +348,9 @@ ipa_comdats (void)
     }
 
   /* Finally assign symbols to the sections.  */
-
+  cgraph_node *fun;
   FOR_EACH_DEFINED_SYMBOL (symbol)
     {
-      struct cgraph_node *fun;
       symbol->aux = NULL; 
       if (!symbol->get_comdat_group ()
 	  && !symbol->alias
@@ -388,6 +387,20 @@ ipa_comdats (void)
 		   true);
 	}
     }
+
+  /* Instrumentation thunks reference original node and thus
+     need to be in the same comdat group.  Otherwise we may
+     get a local instrumented symbol in a comdat group and
+     the referencing original node outside of it.  */
+  FOR_EACH_DEFINED_FUNCTION (fun)
+    if (fun->instrumentation_clone
+	&& fun->instrumented_version
+	&& !fun->instrumented_version->alias
+	&& fun->get_comdat_group ()
+	&& !fun->instrumented_version->get_comdat_group ())
+      fun->instrumented_version->call_for_symbol_and_aliases
+	(set_comdat_group_1, fun, true);
+
   return 0;
 }
 
diff --git a/gcc/testsuite/gcc.target/i386/mpx/chkp-thunk-comdat-1.cc b/gcc/testsuite/gcc.target/i386/mpx/chkp-thunk-comdat-1.cc
new file mode 100644
index 0000000..26d3c48
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/mpx/chkp-thunk-comdat-1.cc
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcheck-pointer-bounds -mmpx" } */
+
+namespace
+{
+  template <int dim>
+  int __attribute__((noinline))
+  f1 ()
+  {
+    return dim;
+  }
+}
+
+int
+test ()
+{
+  return f1<3> ();
+}
diff --git a/gcc/testsuite/gcc.target/i386/mpx/chkp-thunk-comdat-2.cc b/gcc/testsuite/gcc.target/i386/mpx/chkp-thunk-comdat-2.cc
new file mode 100644
index 0000000..2b1abe9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/mpx/chkp-thunk-comdat-2.cc
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcheck-pointer-bounds -mmpx" } */
+
+class c1
+{
+public:
+  virtual int test1 (const char *);
+};
+
+class c2
+{
+public:
+  int test2 (const char *);
+};
+
+int
+c1::test1 (const char *)
+{
+  return 0;
+}
+
+int
+c2::test2 (const char *)
+{
+  return 0;
+}