diff mbox

Fix ICE in initialize_node_lattices

Message ID 20160310161258.GB47843@kam.mff.cuni.cz
State New
Headers show

Commit Message

Jan Hubicka March 10, 2016, 4:12 p.m. UTC
Hi,
this patch fixes ICE in ipa-cp that detects local function that is dead.
The issue is that virutal functions may have no address taken but still may
be virtual call targets.  This patch makes remove_unreachable_nodes to handle
this and not mark them local (since they are not)

Honza

	* cgraph.c (cgraph_node::dump): Dump split_part and indirect_call_target.
	* cgraph.h (cgraph_node): Add indirect_call_target flag.
	* ipa.c (has_addr_references_p): Cleanup.
	(is_indirect_call_target_p): New.
	(walk_polymorphic_call_targets): Do not mark virtuals that may be
	called indirectly as local.
	(symbol_table::remove_unreachable_nodes): Compute indirect_call_target.

	PR lto/69589
	* g++.dg/lto/pr69589_0.C: New testcase
	* g++.dg/lto/pr69589_1.C: New testcase

Comments

Jakub Jelinek March 10, 2016, 4:18 p.m. UTC | #1
On Thu, Mar 10, 2016 at 05:12:59PM +0100, Jan Hubicka wrote:
> --- testsuite/g++.dg/lto/pr69589_0.C	(revision 0)
> +++ testsuite/g++.dg/lto/pr69589_0.C	(working copy)
> @@ -0,0 +1,26 @@
> +// { dg-lto-do link }
> +// { dg-lto-options "-O2 -rdynamic" } 

Shouldn't this have
// { dg-require-visibility "hidden" }
when it uses the visibility push(hidden) ?

> +// { dg-extra-ld-options "-r -nostdlib" }
> +#pragma GCC visibility push(hidden)
> +struct A { int &operator[] (long); };
> +template <typename> struct B;
> +template <typename T, typename = B<T> >
> +using Z = int;
> +template <typename> struct C;
> +struct S {
> +  int e;
> +  virtual ~S () {}
> +};
> +struct D : S {
> +  A a;
> +  long i;
> +  D() { { e ? &a[i] : nullptr; } }
> +};
> +template <>
> +struct C<int> { Z<S> m8 () const; };
> +Z<S>
> +C<int>::m8 () const
> +{
> +  D ();
> +}

	Jakub
Jan Hubicka March 10, 2016, 4:33 p.m. UTC | #2
> On Thu, Mar 10, 2016 at 05:12:59PM +0100, Jan Hubicka wrote:
> > --- testsuite/g++.dg/lto/pr69589_0.C	(revision 0)
> > +++ testsuite/g++.dg/lto/pr69589_0.C	(working copy)
> > @@ -0,0 +1,26 @@
> > +// { dg-lto-do link }
> > +// { dg-lto-options "-O2 -rdynamic" } 
> 
> Shouldn't this have
> // { dg-require-visibility "hidden" }
> when it uses the visibility push(hidden) ?

You are right, I will add it to the testcase.

Honza
> 
> > +// { dg-extra-ld-options "-r -nostdlib" }
> > +#pragma GCC visibility push(hidden)
> > +struct A { int &operator[] (long); };
> > +template <typename> struct B;
> > +template <typename T, typename = B<T> >
> > +using Z = int;
> > +template <typename> struct C;
> > +struct S {
> > +  int e;
> > +  virtual ~S () {}
> > +};
> > +struct D : S {
> > +  A a;
> > +  long i;
> > +  D() { { e ? &a[i] : nullptr; } }
> > +};
> > +template <>
> > +struct C<int> { Z<S> m8 () const; };
> > +Z<S>
> > +C<int>::m8 () const
> > +{
> > +  D ();
> > +}
> 
> 	Jakub
diff mbox

Patch

Index: cgraph.c
===================================================================
--- cgraph.c	(revision 234108)
+++ cgraph.c	(working copy)
@@ -2061,6 +2061,10 @@  cgraph_node::dump (FILE *f)
     fprintf (f, " icf_merged");
   if (merged_comdat)
     fprintf (f, " merged_comdat");
+  if (split_part)
+    fprintf (f, " split_part");
+  if (indirect_call_target)
+    fprintf (f, " indirect_call_target");
   if (nonfreeing_fn)
     fprintf (f, " nonfreeing_fn");
   if (DECL_STATIC_CONSTRUCTOR (decl))
Index: cgraph.h
===================================================================
--- cgraph.h	(revision 234108)
+++ cgraph.h	(working copy)
@@ -1366,6 +1366,8 @@  public:
   unsigned parallelized_function : 1;
   /* True if function is part split out by ipa-split.  */
   unsigned split_part : 1;
+  /* True if the function appears as possible target of indirect call.  */
+  unsigned indirect_call_target : 1;
 
 private:
   /* Worker for call_for_symbol_and_aliases.  */
Index: ipa.c
===================================================================
--- ipa.c	(revision 234108)
+++ ipa.c	(working copy)
@@ -41,7 +41,7 @@  along with GCC; see the file COPYING3.
 
 static bool
 has_addr_references_p (struct cgraph_node *node,
-		       void *data ATTRIBUTE_UNUSED)
+		       void *)
 {
   int i;
   struct ipa_ref *ref = NULL;
@@ -52,6 +52,14 @@  has_addr_references_p (struct cgraph_nod
   return false;
 }
 
+/* Return true when NODE can be target of an indirect call.  */
+
+static bool
+is_indirect_call_target_p (struct cgraph_node *node, void *)
+{
+  return node->indirect_call_target;
+}
+
 /* Look for all functions inlined to NODE and update their inlined_to pointers
    to INLINED_TO.  */
 
@@ -172,23 +180,24 @@  walk_polymorphic_call_targets (hash_set<
 		    (TYPE_METHOD_BASETYPE (TREE_TYPE (n->decl))))
 	    continue;
 
-	   symtab_node *body = n->function_symbol ();
+	  n->indirect_call_target = true;
+	  symtab_node *body = n->function_symbol ();
 
 	  /* Prior inlining, keep alive bodies of possible targets for
 	     devirtualization.  */
-	   if (n->definition
-	       && (before_inlining_p
-		   && opt_for_fn (body->decl, optimize)
-		   && opt_for_fn (body->decl, flag_devirtualize)))
-	      {
-		 /* Be sure that we will not optimize out alias target
-		    body.  */
-		 if (DECL_EXTERNAL (n->decl)
-		     && n->alias
-		     && before_inlining_p)
-		   reachable->add (body);
-		reachable->add (n);
-	      }
+	  if (n->definition
+	      && (before_inlining_p
+		  && opt_for_fn (body->decl, optimize)
+		  && opt_for_fn (body->decl, flag_devirtualize)))
+	     {
+		/* Be sure that we will not optimize out alias target
+		   body.  */
+		if (DECL_EXTERNAL (n->decl)
+		    && n->alias
+		    && before_inlining_p)
+		  reachable->add (body);
+	       reachable->add (n);
+	     }
 	  /* Even after inlining we want to keep the possible targets in the
 	     boundary, so late passes can still produce direct call even if
 	     the chance for inlining is lost.  */
@@ -323,6 +332,7 @@  symbol_table::remove_unreachable_nodes (
   FOR_EACH_FUNCTION (node)
     {
       node->used_as_abstract_origin = false;
+      node->indirect_call_target = false;
       if (node->definition
 	  && !node->global.inlined_to
 	  && !node->in_other_partition
@@ -659,7 +669,14 @@  symbol_table::remove_unreachable_nodes (
 	      fprintf (file, " %s", node->name ());
 	    node->address_taken = false;
 	    changed = true;
-	    if (node->local_p ())
+	    if (node->local_p ()
+		/* Virtual functions may be kept in cgraph just because
+		   of possible later devirtualization.  Do not mark them as
+		   local too early so we won't optimize them out before
+		   we are done with polymorphic call analysis.  */
+		&& (!before_inlining_p
+		    || !node->call_for_symbol_and_aliases
+		       (is_indirect_call_target_p, NULL, true)))
 	      {
 		node->local.local = true;
 		if (file)
Index: testsuite/g++.dg/lto/pr69589_0.C
===================================================================
--- testsuite/g++.dg/lto/pr69589_0.C	(revision 0)
+++ testsuite/g++.dg/lto/pr69589_0.C	(working copy)
@@ -0,0 +1,26 @@ 
+// { dg-lto-do link }
+// { dg-lto-options "-O2 -rdynamic" } 
+// { dg-extra-ld-options "-r -nostdlib" }
+#pragma GCC visibility push(hidden)
+struct A { int &operator[] (long); };
+template <typename> struct B;
+template <typename T, typename = B<T> >
+using Z = int;
+template <typename> struct C;
+struct S {
+  int e;
+  virtual ~S () {}
+};
+struct D : S {
+  A a;
+  long i;
+  D() { { e ? &a[i] : nullptr; } }
+};
+template <>
+struct C<int> { Z<S> m8 () const; };
+Z<S>
+C<int>::m8 () const
+{
+  D ();
+}
+
Index: testsuite/g++.dg/lto/pr69589_1.C
===================================================================
--- testsuite/g++.dg/lto/pr69589_1.C	(revision 0)
+++ testsuite/g++.dg/lto/pr69589_1.C	(working copy)
@@ -0,0 +1,61 @@ 
+struct A;
+template <class T>
+struct Q { Q (T); };
+template<typename T, class D>
+struct U {
+  ~U () { m1 (nullptr); }
+  D m2 ();
+  T *u;
+  void m1 (T *) { m2 () (u); }
+};
+struct F { F (int *); };
+template <class, class T = F>
+using W = Q<T>;
+int a, b;
+void fn1 (void *);
+template <class T>
+void
+fn2 (T *x)
+{
+  if (x)
+    x->~T();
+  fn1 (x);
+}
+template <typename T>
+struct C {
+  void operator() (T *x) { fn2 (x); }
+};
+struct D;
+template <typename T, typename D = C<T> >
+using V = U<T, D>;
+struct A {
+  A (int *);
+};
+struct S;
+struct G {
+  V<S> m3 ();
+};
+struct S {
+  int e;
+  virtual ~S () {}
+};
+template<typename T>
+struct H {
+  H (int, T x, int) : h(x) {}
+  G g;
+  void m4 () { g.m3 (); }
+  T h;
+};
+struct I {
+  I(A, W<D>);
+};
+void
+test ()
+{
+  A c (&b);
+  W<D> d (&b);
+  I e (c, d);
+  H<I> f (0, e, a);
+  f.m4 ();
+}
+