Fix PR c++/68711 - [6 regression] SEGV on an invalid offsetof of a member

of a virtual base.

gcc/testsuite/ChangeLog:
	* g++.dg/other/offsetof8.C: New test.

gcc/cp/ChangeLog:
	* typeck.c (build_class_member_access_expr): Strip NOPs before
        testing a potentially null operand for equality to zero.

From-SVN: r231437

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 7569a62..ac41ca6 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2015-12-08  Martin Sebor  <msebor@redhat.com>
+
+       PR c++/68711
+       * typeck.c (build_class_member_access_expr): Strip NOPs before
+        testing a potentially null operand for equality to zero.
+
 2015-12-07  Jakub Jelinek  <jakub@redhat.com>
 
        PR c++/68760

diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 3cf3c95..17671ee 100644 (file)
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -2358,8 +2358,11 @@ build_class_member_access_expr (cp_expr object, tree member,
       int type_quals;
       tree member_type;
 
-      null_object_p = (INDIRECT_REF_P (object)
-                      && integer_zerop (TREE_OPERAND (object, 0)));
+      if (INDIRECT_REF_P (object))
+       null_object_p =
+         integer_zerop (tree_strip_nop_conversions (TREE_OPERAND (object, 0)));
+      else
+       null_object_p = false;
 
       /* Convert OBJECT to the type of MEMBER.  */
       if (!same_type_p (TYPE_MAIN_VARIANT (object_type),

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b596b03..5cefc07 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-12-08  Martin Sebor  <msebor@redhat.com>
+
+       PR c++/68711
+       * g++.dg/other/offsetof8.C: New test.
+
 2015-12-08  Nathan Sidwell  <nathan@acm.org>
 
        * gcc.target/nvptx/trailing-init.c: New.

diff --git a/gcc/testsuite/g++.dg/other/offsetof8.C b/gcc/testsuite/g++.dg/other/offsetof8.C
new file mode 100644 (file)
index 0000000..daca70a
--- /dev/null
+++ b/gcc/testsuite/g++.dg/other/offsetof8.C
@@ -0,0 +1,12 @@
+// PR c++/68711 - [5 regression] SEGV on an invalid offsetof of a member
+//                of a virtual base
+// { dg-do compile }
+
+struct A { int i; };
+
+struct B: virtual A { };
+
+int a[]  = {
+  !&((B*)0)->i,    // { dg-error "invalid access to non-static data member" }
+  __builtin_offsetof (B, i)   // { dg-error "invalid access to non-static" }
+};