re PR c++/65942 ([C++14] cannot use std::function as comparator in algorithms)

	PR c++/65942
	* decl2.c (mark_used): Don't always instantiate constexpr fns.
	* constexpr.c (cxx_eval_call_expression): Instantiate them here.

From-SVN: r224008

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 78d779133a6ebe8cea6f114b214c2ae5aef035e2..be1a3f967172f358e0204346c8f6a38a4ab1aabd 100644 (file)
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,5 +1,9 @@
 2015-06-01  Jason Merrill  <jason@redhat.com>
 
+       PR c++/65942
+       * decl2.c (mark_used): Don't always instantiate constexpr fns.
+       * constexpr.c (cxx_eval_call_expression): Instantiate them here.
+
        PR c++/44282
        * mangle.c (attr_strcmp): New.
        (write_CV_qualifiers_for_type): Also write out attributes that

diff --git a/gcc/cp/constexpr.c b/gcc/cp/constexpr.c
index ff5489fe029c9d69f3a623fc1395f9430f24b0ad..d05372a5ac13a6845b6556133eb4863dd03f7f01 100644 (file)
--- a/gcc/cp/constexpr.c
+++ b/gcc/cp/constexpr.c
@@ -1240,6 +1240,15 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
        return build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false);
     }
 
+  /* We can't defer instantiating the function any longer.  */
+  if (!DECL_INITIAL (fun)
+      && DECL_TEMPLOID_INSTANTIATION (fun))
+    {
+      ++function_depth;
+      instantiate_decl (fun, /*defer_ok*/false, /*expl_inst*/false);
+      --function_depth;
+    }
+
   /* If in direct recursive call, optimize definition search.  */
   if (ctx && ctx->call && ctx->call->fundef->decl == fun)
     new_call.fundef = ctx->call->fundef;

diff --git a/gcc/cp/decl2.c b/gcc/cp/decl2.c
index f1b3d0cbc6a8824fdb78c62235107a5bced0e40c..8ba19cfda19bbfc5573a24bd29425c82a45a4c0a 100644 (file)
--- a/gcc/cp/decl2.c
+++ b/gcc/cp/decl2.c
@@ -5046,8 +5046,7 @@ mark_used (tree decl, tsubst_flags_t complain)
       && DECL_TEMPLATE_INFO (decl)
       && (decl_maybe_constant_var_p (decl)
          || (TREE_CODE (decl) == FUNCTION_DECL
-             && (DECL_DECLARED_CONSTEXPR_P (decl)
-                 || DECL_OMP_DECLARE_REDUCTION_P (decl)))
+             && DECL_OMP_DECLARE_REDUCTION_P (decl))
          || undeduced_auto_decl (decl))
       && !uses_template_parms (DECL_TI_ARGS (decl)))
     {

diff --git a/gcc/testsuite/g++.dg/cpp0x/constexpr-decltype2.C b/gcc/testsuite/g++.dg/cpp0x/constexpr-decltype2.C
new file mode 100644 (file)
index 0000000..15ca995
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/constexpr-decltype2.C
@@ -0,0 +1,7 @@
+// PR c++/65942
+// { dg-do compile { target c++11 } }
+
+template <typename T> constexpr int f(T t) { return t; }
+template <typename T, typename = decltype(f(T()))> void g(T) { }
+void g(...) { }
+int main() { g(""); }