diff mbox

Reset contexts in possible_polymorphic_call_targets properly

Message ID 20141108220825.GF31830@virgil.suse
State New
Headers show

Commit Message

Martin Jambor Nov. 8, 2014, 10:08 p.m. UTC 
Hi

in a patch I work on I store ipa_polymorphic_call_contexts in a vector
and thus they do not get properly constructed, merely memset to zero.
This means that I happen to be using "know nothing" contexts which
have their outer_type set to NULL but the various flags are also
false, unlike in the properly constructed ones.

When I pass such context to possible_polymorphic_call_targets, I get
wrong complete results of size one because it sets the outer_type to
otr_type but leaves the maybe_derived_type flag cleared.  So I changed
the function to reset the context using clear_outer_type(otr_type)
instead, which I believe is the proper way of doing it.  However, I
had to make that method public to do so.

Bootstrapped and tested on x86_64-linux.  OK for trunk?

Thanks,

Martin


2014-11-08  Martin Jambor  <mjambor@suse.cz>

	* cgraph.h (clear_outer_type): Make public.  Fix comment.
	* ipa-devirt.c (possible_polymorphic_call_targets): Use
	clear_outer_type when resetting the context.

Comments

Jan Hubicka Nov. 10, 2014, 3:48 p.m. UTC | #1 
> Hi
> 
> in a patch I work on I store ipa_polymorphic_call_contexts in a vector
> and thus they do not get properly constructed, merely memset to zero.
> This means that I happen to be using "know nothing" contexts which
> have their outer_type set to NULL but the various flags are also
> false, unlike in the properly constructed ones.
> 
> When I pass such context to possible_polymorphic_call_targets, I get
> wrong complete results of size one because it sets the outer_type to
> otr_type but leaves the maybe_derived_type flag cleared.  So I changed
> the function to reset the context using clear_outer_type(otr_type)
> instead, which I believe is the proper way of doing it.  However, I
> had to make that method public to do so.
> 
> Bootstrapped and tested on x86_64-linux.  OK for trunk?
> 
> Thanks,
> 
> Martin
> 
> 
> 2014-11-08  Martin Jambor  <mjambor@suse.cz>
> 
> 	* cgraph.h (clear_outer_type): Make public.  Fix comment.
> 	* ipa-devirt.c (possible_polymorphic_call_targets): Use

Hmm, it is kind of hack (it would be better to avoid using malformed contextes around)
but OK.

Honza
diff mbox

Patch

Index: src/gcc/cgraph.h
===================================================================
--- src.orig/gcc/cgraph.h	2014-11-05 17:12:51.284464567 +0100
+++ src/gcc/cgraph.h	2014-11-08 19:53:22.726610625 +0100
@@ -1334,6 +1334,10 @@  public:
   /* Make context non-speculative.  */
   void clear_speculation ();
 
+  /* Produce context specifying all derrived types of OTR_TYPE.  If OTR_TYPE is
+     NULL, the context is set to dummy "I know nothing" setting.  */
+  void clear_outer_type (tree otr_type = NULL);
+
   /* Walk container types and modify context to point to actual class
      containing OTR_TYPE (if non-NULL) as base class.
      Return true if resulting context is valid.
@@ -1374,7 +1378,6 @@  private:
   bool combine_speculation_with (tree, HOST_WIDE_INT, bool, tree);
   void set_by_decl (tree, HOST_WIDE_INT);
   bool set_by_invariant (tree, tree, HOST_WIDE_INT);
-  void clear_outer_type (tree otr_type = NULL);
   bool speculation_consistent_p (tree, HOST_WIDE_INT, bool, tree);
   void make_speculative (tree otr_type = NULL);
 };
@@ -2724,9 +2727,8 @@  ipa_polymorphic_call_context::clear_spec
   speculative_maybe_derived_type = false;
 }
 
-/* Produce context specifying all derrived types of OTR_TYPE.
-   If OTR_TYPE is NULL or type of the OBJ_TYPE_REF, the context is set
-   to dummy "I know nothing" setting.  */
+/* Produce context specifying all derrived types of OTR_TYPE.  If OTR_TYPE is
+   NULL, the context is set to dummy "I know nothing" setting.  */
 
 inline void
 ipa_polymorphic_call_context::clear_outer_type (tree otr_type)
Index: src/gcc/ipa-devirt.c
===================================================================
--- src.orig/gcc/ipa-devirt.c	2014-11-03 20:17:30.200011833 +0100
+++ src/gcc/ipa-devirt.c	2014-11-08 19:48:47.882600150 +0100
@@ -2281,10 +2281,7 @@  possible_polymorphic_call_targets (tree
   /* Without outer type, we have no use for offset.  Just do the
      basic search from innter type  */
   if (!context.outer_type)
-    {
-      context.outer_type = otr_type;
-      context.offset = 0;
-    }
+    context.clear_outer_type (otr_type);
   /* We need to update our hiearchy if the type does not exist.  */
   outer_type = get_odr_type (context.outer_type, true);
   /* If the type is complete, there are no derivations.  */