Re: Fix ice on comdat groups with -check-pointer-bounds

[Ilya Enkovich]

On 30 Mar 14:05, Ilya Enkovich wrote:
> 2015-03-27 18:23 GMT+03:00 Jan Hubicka <hubi...@ucw.cz>:
> > Index: symtab.c
> > ===================================================================
> > --- symtab.c    (revision 221734)
> > +++ symtab.c    (working copy)
> > @@ -1130,15 +1130,20 @@ symtab_node::verify_symtab_nodes (void)
> >                                                   &existed);
> >           if (!existed)
> >             *entry = node;
> > -         else
> > -           for (s = (*entry)->same_comdat_group; s != NULL && s != node; s 
> > = s->same_comdat_group)
> > +         else if (!DECL_EXTERNAL (node->decl))
> > +           {
> > +             for (s = (*entry)->same_comdat_group; s != NULL && s != node;
> > +                  s = s->same_comdat_group)
> > +               ;
> 
> With no if-statement in the loop body you need an additional exit
> condition for a case when you reach the entry.
> 
> Thanks,
> Ilya
> 

Here is a patch to add a testcase, fix the loop and avoid same_comdat_group for 
instrumented external symbols.  Does it look OK?

BTW should we check same_comdat_group is NULL for external symbols?

Thanks,
Ilya
--
gcc/

2015-03-30  Ilya Enkovich  <ilya.enkov...@intel.com>

        PR target/65531
        * ipa-chkp.c (chkp_maybe_create_clone): Don't set
        same_comdat_group for external symbols.
        * symtab.c (symtab_node::verify_symtab_nodes): Avoid
        infinite same_comdat_group traversal loop.

gcc/testsuite/

2015-03-30  Ilya Enkovich  <ilya.enkov...@intel.com>

        PR target/65531
        * gcc.target/i386/mpx/pr65531.cc: New.


diff --git a/gcc/ipa-chkp.c b/gcc/ipa-chkp.c
index a9933e2..3218d42 100644
--- a/gcc/ipa-chkp.c
+++ b/gcc/ipa-chkp.c
@@ -574,7 +574,8 @@ chkp_maybe_create_clone (tree fndecl)
 
       /* Clones have the same comdat group as originals.  */
       if (node->same_comdat_group
-         || DECL_ONE_ONLY (node->decl))
+         || (DECL_ONE_ONLY (node->decl)
+             && !DECL_EXTERNAL (node->decl)))
        clone->add_to_same_comdat_group (node);
 
       if (gimple_has_body_p (fndecl))
diff --git a/gcc/symtab.c b/gcc/symtab.c
index eb41d62..156fa3d 100644
--- a/gcc/symtab.c
+++ b/gcc/symtab.c
@@ -1132,7 +1132,8 @@ symtab_node::verify_symtab_nodes (void)
            *entry = node;
          else if (!DECL_EXTERNAL (node->decl))
            {
-             for (s = (*entry)->same_comdat_group; s != NULL && s != node;
+             for (s = (*entry)->same_comdat_group;
+                  s != NULL && s != node && s != *entry;
                   s = s->same_comdat_group)
                ;
              if (!s || s == *entry)
diff --git a/gcc/testsuite/gcc.target/i386/mpx/pr65531.cc 
b/gcc/testsuite/gcc.target/i386/mpx/pr65531.cc
new file mode 100644
index 0000000..049569c
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/mpx/pr65531.cc
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fcheck-pointer-bounds -mmpx" } */
+
+#pragma interface
+
+struct S
+{
+  ~S ()
+  {
+  }
+};
+
+S s;