Hi,
On 12/01/2012 07:13 AM, Jason Merrill wrote:
On 11/30/2012 04:05 PM, Paolo Carlini wrote:
@@ -219,10 +219,15 @@ cp_convert_to_pointer (tree type, tree expr, tsubs
- expr = build_int_cst (type, 0);
+ expr = (TREE_SIDE_EFFECTS (expr)
+ ? build_nop (type, expr)
+ : build_int_cst (type, 0));
This seems to rely on a nop being sufficient to convert from any null
pointer constant to the appropriate pointer type, which I don't think
is safe if the integer is smaller than a pointer.
I'm also not sure if we want to rely on nullptr_t expressions actually
having the value 0.
Thanks a lot. What about the below? I'm consistently building a
COMPOUND_EXPR for the simpler plain pointers too; the hunk for pointers
to member functions can be *very* simple: in fact I had already tried
this solution but something else was wrong yesterday and seemed not to
work, huumpf.
Tested x86_64-linux.
Thanks again,
Paolo.
////////////////////
Index: cp/cvt.c
===================================================================
--- cp/cvt.c (revision 194020)
+++ cp/cvt.c (working copy)
@@ -215,16 +215,14 @@ cp_convert_to_pointer (tree type, tree expr, tsubs
return build_ptrmemfunc (TYPE_PTRMEMFUNC_FN_TYPE (type), expr, 0,
/*c_cast_p=*/false, complain);
- if (TYPE_PTRDATAMEM_P (type))
- {
- /* A NULL pointer-to-member is represented by -1, not by
- zero. */
- expr = build_int_cst_type (type, -1);
- }
- else
- expr = build_int_cst (type, 0);
+ /* A NULL pointer-to-data-member is represented by -1, not by
+ zero. */
+ tree val = (TYPE_PTRDATAMEM_P (type)
+ ? build_int_cst_type (type, -1)
+ : build_int_cst (type, 0));
- return expr;
+ return (TREE_SIDE_EFFECTS (expr)
+ ? build2 (COMPOUND_EXPR, type, expr, val) : val);
}
else if (TYPE_PTRMEM_P (type) && INTEGRAL_CODE_P (form))
{
Index: cp/typeck.c
===================================================================
--- cp/typeck.c (revision 194020)
+++ cp/typeck.c (working copy)
@@ -7567,7 +7567,7 @@ build_ptrmemfunc (tree type, tree pfn, int force,
/* Handle null pointer to member function conversions. */
if (null_ptr_cst_p (pfn))
{
- pfn = build_c_cast (input_location, type, nullptr_node);
+ pfn = build_c_cast (input_location, type, pfn);
return build_ptrmemfunc1 (to_type,
integer_zero_node,
pfn);
Index: testsuite/g++.dg/cpp0x/lambda/lambda-nullptr.C
===================================================================
--- testsuite/g++.dg/cpp0x/lambda/lambda-nullptr.C (revision 0)
+++ testsuite/g++.dg/cpp0x/lambda/lambda-nullptr.C (working copy)
@@ -0,0 +1,47 @@
+// PR c++/54170
+// { dg-do run { target c++11 } }
+
+#include <cassert>
+
+struct A;
+typedef A* ptr;
+typedef int (A::*pmf) (int);
+typedef int (A::*pdm);
+
+int total;
+
+void add(int n)
+{
+ total += n;
+}
+
+template <typename RType, typename Callable>
+RType Call(Callable native_func, int arg)
+{
+ return native_func(arg);
+}
+
+template <typename RType>
+RType do_test(int delta)
+{
+ return Call<RType>([=](int delta) { add(delta); return nullptr; }, delta);
+}
+
+template <typename RType>
+void test()
+{
+ total = 0;
+ assert (!do_test<RType>(5));
+ assert (total == 5);
+ assert (!do_test<RType>(20));
+ assert (total == 25);
+ assert (!do_test<RType>(-256));
+ assert (total == -231);
+}
+
+int main()
+{
+ test<ptr>();
+ test<pdm>();
+ test<pmf>();
+}
