Re: C++ PATCH for c++/68586 (rejects-valid with enum in C++11)

[Marek Polacek <polacek at redhat dot com>]

On Mon, Jan 18, 2016 at 01:06:46PM -0500, Jason Merrill wrote:
> Yes, and let's also clear the fold_cache at the same time.

Ah, that one as well.  Thus:

Bootstrapped/regtested on x86_64-linux, ok for trunk?

2016-01-18  Marek Polacek  <polacek@redhat.com>

	PR c++/68586
	* constexpr.c (clear_cv_cache): New.
	* cp-gimplify.c (clear_fold_cache): New.
	* cp-tree.h (clear_cv_cache, clear_fold_cache): Declare.
	* decl.c (finish_enum_value_list): Call them.

	* g++.dg/cpp0x/enum30.C: New test.

diff --git gcc/cp/constexpr.c gcc/cp/constexpr.c
index 6ab4696..6b0e5a8 100644
--- gcc/cp/constexpr.c
+++ gcc/cp/constexpr.c
@@ -4027,6 +4027,14 @@ maybe_constant_value (tree t, tree decl)
   return ret;
 }
 
+/* Dispose of the whole CV_CACHE.  */
+
+void
+clear_cv_cache (void)
+{
+  gt_cleare_cache (cv_cache);
+}
+
 /* Like maybe_constant_value but first fully instantiate the argument.
 
    Note: this is equivalent to instantiate_non_dependent_expr_sfinae
diff --git gcc/cp/cp-gimplify.c gcc/cp/cp-gimplify.c
index 5c4d3c1..3f96901 100644
--- gcc/cp/cp-gimplify.c
+++ gcc/cp/cp-gimplify.c
@@ -1896,6 +1896,14 @@ c_fully_fold (tree x, bool /*in_init*/, bool */*maybe_const*/)
 
 static GTY((cache, deletable)) cache_map fold_cache;
 
+/* Dispose of the whole FOLD_CACHE.  */
+
+void
+clear_fold_cache (void)
+{
+  gt_cleare_cache (fold_cache);
+}
+
 /*  This function tries to fold an expression X.
     To avoid combinatorial explosion, folding results are kept in fold_cache.
     If we are processing a template or X is invalid, we don't fold at all.
diff --git gcc/cp/cp-tree.h gcc/cp/cp-tree.h
index fc9507e..51589c3 100644
--- gcc/cp/cp-tree.h
+++ gcc/cp/cp-tree.h
@@ -6819,6 +6819,7 @@ extern bool cxx_omp_privatize_by_reference	(const_tree);
 extern bool cxx_omp_disregard_value_expr	(tree, bool);
 extern void cp_fold_function			(tree);
 extern tree cp_fully_fold			(tree);
+extern void clear_fold_cache			(void);
 
 /* in name-lookup.c */
 extern void suggest_alternatives_for            (location_t, tree);
@@ -6919,6 +6920,7 @@ extern bool var_in_constexpr_fn                 (tree);
 extern void explain_invalid_constexpr_fn        (tree);
 extern vec<tree> cx_error_context               (void);
 extern tree fold_sizeof_expr			(tree);
+extern void clear_cv_cache			(void);
 
 /* In c-family/cilk.c */
 extern bool cilk_valid_spawn                    (tree);
diff --git gcc/cp/decl.c gcc/cp/decl.c
index df95133..df925b8 100644
--- gcc/cp/decl.c
+++ gcc/cp/decl.c
@@ -13386,6 +13386,11 @@ finish_enum_value_list (tree enumtype)
 
   /* Finish debugging output for this type.  */
   rest_of_type_compilation (enumtype, namespace_bindings_p ());
+
+  /* Each enumerator now has the type of its enumeration.  Clear the cache
+     so that this change in types doesn't confuse us later on.  */
+  clear_cv_cache ();
+  clear_fold_cache ();
 }
 
 /* Finishes the enum type. This is called only the first time an
diff --git gcc/testsuite/g++.dg/cpp0x/enum30.C gcc/testsuite/g++.dg/cpp0x/enum30.C
index e69de29..cf0c1b5 100644
--- gcc/testsuite/g++.dg/cpp0x/enum30.C
+++ gcc/testsuite/g++.dg/cpp0x/enum30.C
@@ -0,0 +1,14 @@
+// PR c++/68586
+// { dg-do compile { target c++11 } }
+
+enum E { x , y = 1 + (x << 1) };
+template<E> struct A {};
+A<x> a;
+
+enum E2 : int { x2 , y2 = x2 << 1 };
+template<E2> struct A2 {};
+A2<x2> a2;
+
+enum class E3 { x3 , y3 = x3 << 1 };
+template<E3> struct A3 {};
+A3<E3::x3> a3;

	Marek