gcc/ChangeLog:

PR c++/20280
* gimplify.c (gimplify_cond_expr): Add fallback argument.  Use a
temporary variable of pointer type if an lvalues is required.
(gimplify_modify_expr_rhs): Request an rvalue from it.
(gimplify_expr): Pass fallback on.
gcc/testsuite/ChangeLog:
PR c++/20280
* g++.dg/tree-ssa/pr20280.C: New.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@96444 138bc75d-0d04-0410-961f-82ee72b054a4

4 files changed, 107 insertions, 6 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 54c0d114859..910eb398c9f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2005-03-14  Alexandre Oliva  <aoliva@redhat.com>
+
+	PR c++/20280
+	* gimplify.c (gimplify_cond_expr): Add fallback argument.  Use a
+	temporary variable of pointer type if an lvalues is required.
+	(gimplify_modify_expr_rhs): Request an rvalue from it.
+	(gimplify_expr): Pass fallback on.
+
 2005-03-14  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* cfgbuild.c: Update comments.
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 9a6d3076f13..f16ff201694 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -2123,7 +2123,8 @@ gimple_boolify (tree expr)
      *EXPR_P should be stored.  */
 
 static enum gimplify_status
-gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target)
+gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target,
+		    fallback_t fallback)
 {
   tree expr = *expr_p;
   tree tmp, tmp2, type;
@@ -2137,18 +2138,40 @@ gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target)
      the arms.  */
   else if (! VOID_TYPE_P (type))
     {
+      tree result;
+
       if (target)
 	{
 	  ret = gimplify_expr (&target, pre_p, post_p,
 			       is_gimple_min_lval, fb_lvalue);
 	  if (ret != GS_ERROR)
 	    ret = GS_OK;
-	  tmp = target;
+	  result = tmp = target;
 	  tmp2 = unshare_expr (target);
 	}
+      else if ((fallback & fb_lvalue) == 0)
+	{
+	  result = tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
+	  ret = GS_ALL_DONE;
+	}
       else
 	{
-	  tmp2 = tmp = create_tmp_var (TREE_TYPE (expr), "iftmp");
+	  tree type = build_pointer_type (TREE_TYPE (expr));
+
+	  if (TREE_TYPE (TREE_OPERAND (expr, 1)) != void_type_node)
+	    TREE_OPERAND (expr, 1) =
+	      build_fold_addr_expr (TREE_OPERAND (expr, 1));
+
+	  if (TREE_TYPE (TREE_OPERAND (expr, 2)) != void_type_node)
+	    TREE_OPERAND (expr, 2) =
+	      build_fold_addr_expr (TREE_OPERAND (expr, 2));
+	  
+	  tmp2 = tmp = create_tmp_var (type, "iftmp");
+
+	  expr = build (COND_EXPR, void_type_node, TREE_OPERAND (expr, 0),
+			TREE_OPERAND (expr, 1), TREE_OPERAND (expr, 2));
+
+	  result = build_fold_indirect_ref (tmp);
 	  ret = GS_ALL_DONE;
 	}
 
@@ -2169,7 +2192,7 @@ gimplify_cond_expr (tree *expr_p, tree *pre_p, tree *post_p, tree target)
       /* Move the COND_EXPR to the prequeue.  */
       gimplify_and_add (expr, pre_p);
 
-      *expr_p = tmp;
+      *expr_p = result;
       return ret;
     }
 
@@ -2907,7 +2930,8 @@ gimplify_modify_expr_rhs (tree *expr_p, tree *from_p, tree *to_p, tree *pre_p,
 	if (!is_gimple_reg_type (TREE_TYPE (*from_p)))
 	  {
 	    *expr_p = *from_p;
-	    return gimplify_cond_expr (expr_p, pre_p, post_p, *to_p);
+	    return gimplify_cond_expr (expr_p, pre_p, post_p, *to_p,
+				       fb_rvalue);
 	  }
 	else
 	  ret = GS_UNHANDLED;
@@ -3786,7 +3810,8 @@ gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p,
 	  break;
 
 	case COND_EXPR:
-	  ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE);
+	  ret = gimplify_cond_expr (expr_p, pre_p, post_p, NULL_TREE,
+				    fallback);
 	  break;
 
 	case CALL_EXPR:
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index ef6463180c6..4e18492dbab 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2005-03-14  Alexandre Oliva  <aoliva@redhat.com>
+
+	PR c++/20280
+	* g++.dg/tree-ssa/pr20280.C: New.
+
 2005-03-14  Tobias Schl"uter  <tobias.schlueter@physik.uni-muenchen.de>
 
 	PR fortran/20467
diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr20280.C b/gcc/testsuite/g++.dg/tree-ssa/pr20280.C
new file mode 100644
index 00000000000..ec4dad70620
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr20280.C
@@ -0,0 +1,63 @@
+// PR c++/20280
+
+// { dg-do compile }
+
+// Gimplification of the COND_EXPR used to fail because it had an
+// addressable type, and create_tmp_var rejected that.
+
+struct A
+{
+    ~A();
+};
+
+struct B : A {};
+
+A& foo();
+
+void bar(bool b)
+{
+    (B&) (b ? foo() : foo());
+}
+
+// Make sure bit-fields and addressable types don't cause crashes.
+// These were not in the original bug report.
+
+// Added by Alexandre Oliva <aoliva@redhat.com>
+
+// Copyright 2005 Free Software Foundation
+
+struct X
+{
+  long i : 32, j, k : 32;
+};
+
+void g(long&);
+void h(const long&);
+
+void f(X &x, bool b)
+{
+  (b ? x.i : x.j) = 1;
+  (b ? x.j : x.k) = 2;
+  (b ? x.i : x.k) = 3;
+
+  (void)(b ? x.i : x.j);
+  (void)(b ? x.i : x.k);
+  (void)(b ? x.j : x.k);
+
+  g (b ? x.i : x.j); // { dg-error "cannot bind bitfield" }
+  g (b ? x.i : x.k); // { dg-error "cannot bind bitfield" }
+  g (b ? x.j : x.k); // { dg-error "cannot bind bitfield" }
+
+  // It's not entirely clear whether these should be accepted.  The
+  // conditional expressions are lvalues for sure, and 8.5.3/5 exempts
+  // lvalues for bit-fields, but it's not clear that conditional
+  // expressions that are lvalues and that have at least one possible
+  // result that is a bit-field lvalue meets this condition.
+  h (b ? x.i : x.j);
+  h (b ? x.i : x.k);
+  h (b ? x.j : x.k);
+
+  (long &)(b ? x.i : x.j); // { dg-error "address of bit-field" }
+  (long &)(b ? x.i : x.k); // { dg-error "address of bit-field" }
+  (long &)(b ? x.j : x.k); // { dg-error "address of bit-field" }
+}