The problem here is that we've gotten to potential_constant_expression_1 with a
CLEANUP_STMT, but it doesn't know how to handle that so we ICE. I thought it'd
be possible to look into CLEANUP_{BODY,EXPR} to determine whether the
CLEANUP_STMT can be potentially const, but cxx_eval_constant_expression can't
handle CLEANUP_STMTs so it couldn't evaluate it anyway. So it seems that it's
safe to consider CLEANUP_STMTs non-constant.
This happens when initializing __for_range, where finish_eh_cleanup creates
a CLEANUP_STMT that would run ~A() in case of an exception.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2017-01-03 Marek Polacek <pola...@redhat.com>
PR c++/77545
PR c++/77284
* constexpr.c (potential_constant_expression_1): Handle CLEANUP_STMT.
* g++.dg/cpp0x/range-for32.C: New test.
* g++.dg/cpp0x/range-for33.C: New test.
diff --git gcc/cp/constexpr.c gcc/cp/constexpr.c
index 1e83b0b..a3dec68 100644
--- gcc/cp/constexpr.c
+++ gcc/cp/constexpr.c
@@ -5661,6 +5661,7 @@ potential_constant_expression_1 (tree t, bool want_rval,
bool strict,
/* We can see these in statement-expressions. */
return true;
+ case CLEANUP_STMT:
case EMPTY_CLASS_EXPR:
return false;
diff --git gcc/testsuite/g++.dg/cpp0x/range-for32.C
gcc/testsuite/g++.dg/cpp0x/range-for32.C
index e69de29..375a707 100644
--- gcc/testsuite/g++.dg/cpp0x/range-for32.C
+++ gcc/testsuite/g++.dg/cpp0x/range-for32.C
@@ -0,0 +1,16 @@
+// PR c++/77545
+// { dg-do compile { target c++11 } }
+// { dg-options "-Wno-pedantic" }
+
+template < typename T > struct A
+{
+ A ();
+ ~A ();
+ T t;
+};
+
+void f (A < int > a)
+{
+ for (auto x : (A<int>[]) { a })
+ ;
+}
diff --git gcc/testsuite/g++.dg/cpp0x/range-for33.C
gcc/testsuite/g++.dg/cpp0x/range-for33.C
index e69de29..206f36e 100644
--- gcc/testsuite/g++.dg/cpp0x/range-for33.C
+++ gcc/testsuite/g++.dg/cpp0x/range-for33.C
@@ -0,0 +1,14 @@
+// PR c++/77284
+// { dg-do compile { target c++11 } }
+
+#include <initializer_list>
+
+struct A
+{
+ ~A () {}
+};
+
+void foo (A & v)
+{
+ for (A a : { v }) {};
+}
Marek
