re PR c++/33819 (Miscompiled shift of C++ bitfield)

2008-01-16  Richard Guenther  <rguenther@suse.de>

	PR c++/33819
	* typeck.c (is_bitfield_expr_with_lowered_type): Recurse
	for conversions to type variants.

	* g++.dg/torture/pr33819.C: New testcase.

From-SVN: r131569

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 8582460..030232b 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2008-01-16  Richard Guenther  <rguenther@suse.de>
+
+       PR c++/33819
+       * typeck.c (is_bitfield_expr_with_lowered_type): Recurse
+       for conversions to type variants.
+
 2008-01-15  Andreas Tobler  <a.tobler@schweiz.org>
 
        * parser.c (cp_parser_template_parameter): Fix C90 issue with mixing

diff --git a/gcc/cp/typeck.c b/gcc/cp/typeck.c
index 50a844a..6557637 100644 (file)
--- a/gcc/cp/typeck.c
+++ b/gcc/cp/typeck.c
@@ -1445,6 +1445,13 @@ is_bitfield_expr_with_lowered_type (const_tree exp)
        return DECL_BIT_FIELD_TYPE (field);
       }
 
+    case NOP_EXPR:
+    case CONVERT_EXPR:
+      if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (exp, 0)))
+         == TYPE_MAIN_VARIANT (TREE_TYPE (exp)))
+       return is_bitfield_expr_with_lowered_type (TREE_OPERAND (exp, 0));
+      /* Fallthrough.  */
+
     default:
       return NULL_TREE;
     }

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index b69ff98..e274836 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2008-01-16  Richard Guenther  <rguenther@suse.de>
 
+       PR c++/33819
+       * g++.dg/torture/pr33819.C: New testcase.
+
+2008-01-16  Richard Guenther  <rguenther@suse.de>
+
        PR c/34768
        * gcc.c-torture/execute/pr34768-1.c: New testcase.
        * gcc.c-torture/execute/pr34768-2.c: Likewise.

diff --git a/gcc/testsuite/g++.dg/torture/pr33819.C b/gcc/testsuite/g++.dg/torture/pr33819.C
new file mode 100644 (file)
index 0000000..a2f868d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr33819.C
@@ -0,0 +1,22 @@
+/* { dg-do run } */
+
+class s
+{
+public:
+  s(long long aa) : a(aa), i1(0) { }
+  long long id() const { return (this->a << 16) >> 16; }
+  bool operator< (s sv) { return this->a < sv.id(); }
+private:
+  long long a : 48;
+  int i1 : 16;
+};
+s g(1);
+extern "C" void abort (void);
+int
+main(int, char**)
+{
+  if (g < (1LL << 38) - 1)
+    return 0;
+  abort ();
+}
+