Hi Jason,
On 13/02/2018 15:35, Jason Merrill wrote:
OK.
Thanks. Unfortunately, I don't think I sent a complete solution for
these issues. In fact we would still ICE on:
template<typename T> int foo()
{
return sizeof(T) > 1 ? : 1;
}
because type_contains_placeholder_p doesn't know how to handle a
TEMPLATE_TYPE_PARM. In fact, cp_save_expr teaches me something:
tree
cp_save_expr (tree expr)
{
/* There is no reason to create a SAVE_EXPR within a template; if
needed, we can create the SAVE_EXPR when instantiating the
template. Furthermore, the middle-end cannot handle C++-specific
tree codes. */
if (processing_template_decl)
return expr;
return save_expr (expr);
}
would it be correct to just use it? Or we have to do something more
complex? Note the issue only affects the GNU-extension with omitted
middle operand, thus I believe we have *some* leeway...
Thanks!
Paolo.
/////////////////////
Index: cp/call.c
===================================================================
--- cp/call.c (revision 257627)
+++ cp/call.c (working copy)
@@ -4805,7 +4805,7 @@ build_conditional_expr_1 (location_t loc, tree arg
if (lvalue_p (arg1))
arg2 = arg1 = cp_stabilize_reference (arg1);
else
- arg2 = arg1 = save_expr (arg1);
+ arg2 = arg1 = cp_save_expr (arg1);
}
/* If something has already gone wrong, just pass that fact up the
Index: testsuite/g++.dg/template/sizeof16.C
===================================================================
--- testsuite/g++.dg/template/sizeof16.C (nonexistent)
+++ testsuite/g++.dg/template/sizeof16.C (working copy)
@@ -0,0 +1,7 @@
+// PR c++/84333
+// { dg-options -Wno-pedantic }
+
+template<typename> int foo()
+{
+ return sizeof(int) > 1 ? : 1;
+}
Index: testsuite/g++.dg/template/sizeof17.C
===================================================================
--- testsuite/g++.dg/template/sizeof17.C (nonexistent)
+++ testsuite/g++.dg/template/sizeof17.C (working copy)
@@ -0,0 +1,7 @@
+// PR c++/84333
+// { dg-options -Wno-pedantic }
+
+template<typename T> int foo()
+{
+ return sizeof(T) > 1 ? : 1;
+}
