[PATCH] ipa: check if cache_token != NULL before hash_set::add call

[Martin Liška]

We should not insert an empty value to the container.

Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Ready to be installed?
Thanks,
Martin

        PR ipa/108509

gcc/ChangeLog:

        * cgraphunit.cc (walk_polymorphic_call_targets): Insert
        ony non-null values.
        * ipa.cc (walk_polymorphic_call_targets): Likewise.

gcc/testsuite/ChangeLog:

        * g++.dg/ipa/pr108509.C: New test.
---
 gcc/cgraphunit.cc                   |  2 +-
 gcc/ipa.cc                          |  2 +-
 gcc/testsuite/g++.dg/ipa/pr108509.C | 22 ++++++++++++++++++++++
 3 files changed, 24 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/ipa/pr108509.C

diff --git a/gcc/cgraphunit.cc b/gcc/cgraphunit.cc
index 832818d651f..a972900900b 100644
--- a/gcc/cgraphunit.cc
+++ b/gcc/cgraphunit.cc
@@ -1000,7 +1000,7 @@ walk_polymorphic_call_targets (hash_set<void *> 
*reachable_call_targets,
     = possible_polymorphic_call_targets
        (edge, &final, &cache_token);
 
-  if (!reachable_call_targets->add (cache_token))
+  if (cache_token != NULL && !reachable_call_targets->add (cache_token))
     {
       if (symtab->dump_file)
        dump_possible_polymorphic_call_targets 
diff --git a/gcc/ipa.cc b/gcc/ipa.cc
index 4de605000b6..5c15b60a603 100644
--- a/gcc/ipa.cc
+++ b/gcc/ipa.cc
@@ -182,7 +182,7 @@ walk_polymorphic_call_targets (hash_set<void *> 
*reachable_call_targets,
     = possible_polymorphic_call_targets
        (edge, &final, &cache_token);
 
-  if (!reachable_call_targets->add (cache_token))
+  if (cache_token != NULL && !reachable_call_targets->add (cache_token))
     {
       for (i = 0; i < targets.length (); i++)
        {
diff --git a/gcc/testsuite/g++.dg/ipa/pr108509.C 
b/gcc/testsuite/g++.dg/ipa/pr108509.C
new file mode 100644
index 00000000000..2844189bbb4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ipa/pr108509.C
@@ -0,0 +1,22 @@
+// PR ipa/108509
+// { dg-do compile }
+// { dg-options "-O1 -fdevirtualize -fno-tree-fre" }
+
+struct B {
+  virtual void deref ();
+};
+
+struct RefPtr {
+  B *p;
+
+  RefPtr ()
+  {
+    p->deref ();
+  }
+};
+
+void
+f ()
+{
+  RefPtr b;
+}
-- 
2.39.0