Make __PRETTY_FUNCTION__-like functions mergeable string csts (PR c++/64266).

2018-11-01  Martin Liska  <mliska@suse.cz>
	    Jason Merrill  <jason@redhat.com>

	PR c++/64266
	PR bootstrap/70422
	PR ipa/81277
	* cp-tree.h (DECL_FNAME_P): New macro.
	* decl.c (cp_make_fname_decl): Set DECL_DECLARED_CONSTEXPR_P,
        DECL_VALUE_EXPR, DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P.
	(cp_finish_decl):
	* lambda.c (is_capture_proxy): Use DECL_FNAME_P.
	* pt.c (tsubst_expr): Handle DECL_PRETTY_FUNCTION_P.
2018-11-01  Martin Liska  <mliska@suse.cz>
	    Jason Merrill  <jason@redhat.com>

	PR c++/64266
	PR bootstrap/70422
	PR ipa/81277
	* g++.dg/cpp0x/constexpr-__func__2.C: Make it a compilation
	test.
	* g++.old-deja/g++.ext/pretty4.C: Remove as the run-time
	assumptions are not longer valid.

Co-Authored-By: Jason Merrill <jason@redhat.com>

From-SVN: r265711

5 files changed, 46 insertions, 17 deletions

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index 8e586a1..6d48345 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,16 @@
+2018-11-01  Martin Liska  <mliska@suse.cz>
+	    Jason Merrill  <jason@redhat.com>
+
+	PR c++/64266
+	PR bootstrap/70422
+	PR ipa/81277
+	* cp-tree.h (DECL_FNAME_P): New macro.
+	* decl.c (cp_make_fname_decl): Set DECL_DECLARED_CONSTEXPR_P,
+        DECL_VALUE_EXPR, DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P.
+	(cp_finish_decl):
+	* lambda.c (is_capture_proxy): Use DECL_FNAME_P.
+	* pt.c (tsubst_expr): Handle DECL_PRETTY_FUNCTION_P.
+
 2018-10-31  Nathan Sidwell  <nathan@acm.org>
 
 	* cp-tree.h (OVL_DEDUP_P): New.
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 03e8883..42449f1 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -3132,6 +3132,14 @@ struct GTY(()) lang_decl {
   (DECL_NAME (NODE) \
    && id_equal (DECL_NAME (NODE), "__PRETTY_FUNCTION__"))
 
+/* For a DECL, true if it is __func__ or similar.  */
+#define DECL_FNAME_P(NODE)					\
+  (VAR_P (NODE) && DECL_NAME (NODE) && DECL_ARTIFICIAL (NODE)	\
+   && DECL_HAS_VALUE_EXPR_P (NODE)				\
+   && (id_equal (DECL_NAME (NODE), "__PRETTY_FUNCTION__")	\
+       || id_equal (DECL_NAME (NODE), "__FUNCTION__")		\
+       || id_equal (DECL_NAME (NODE), "__func__")))
+
 /* Nonzero if the variable was declared to be thread-local.
    We need a special C++ version of this test because the middle-end
    DECL_THREAD_LOCAL_P uses the symtab, so we can't use it for
diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
index 11320b6..1cea526 100644
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -4465,7 +4465,7 @@ cp_fname_init (const char* name, tree *type_p)
 static tree
 cp_make_fname_decl (location_t loc, tree id, int type_dep)
 {
-  const char *const name = (type_dep && processing_template_decl
+  const char *const name = (type_dep && in_template_function ()
 			    ? NULL : fname_as_string (type_dep));
   tree type;
   tree init = cp_fname_init (name, &type);
@@ -4474,23 +4474,35 @@ cp_make_fname_decl (location_t loc, tree id, int type_dep)
   if (name)
     free (CONST_CAST (char *, name));
 
-  TREE_STATIC (decl) = 1;
+  /* As we're using pushdecl_with_scope, we must set the context.  */
+  DECL_CONTEXT (decl) = current_function_decl;
+
   TREE_READONLY (decl) = 1;
   DECL_ARTIFICIAL (decl) = 1;
+  DECL_DECLARED_CONSTEXPR_P (decl) = 1;
+  TREE_STATIC (decl) = 1;
 
   TREE_USED (decl) = 1;
 
+  if (init)
+    {
+      SET_DECL_VALUE_EXPR (decl, init);
+      DECL_HAS_VALUE_EXPR_P (decl) = 1;
+      /* For decl_constant_var_p.  */
+      DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = 1;
+    }
+
   if (current_function_decl)
     {
       DECL_CONTEXT (decl) = current_function_decl;
       decl = pushdecl_outermost_localscope (decl);
-      cp_finish_decl (decl, init, /*init_const_expr_p=*/false, NULL_TREE,
-		      LOOKUP_ONLYCONVERTING);
+      if (decl != error_mark_node)
+	add_decl_expr (decl);
     }
   else
     {
       DECL_THIS_STATIC (decl) = true;
-      pushdecl_top_level_and_finish (decl, init);
+      pushdecl_top_level_and_finish (decl, NULL_TREE);
     }
 
   return decl;
@@ -7052,8 +7064,9 @@ cp_finish_decl (tree decl, tree init, bool init_const_expr_p,
 	    init = NULL_TREE;
 	  release_tree_vector (cleanups);
 	}
-      else if (!DECL_PRETTY_FUNCTION_P (decl))
+      else
 	{
+	  gcc_assert (!DECL_PRETTY_FUNCTION_P (decl));
 	  /* Deduce array size even if the initializer is dependent.  */
 	  maybe_deduce_size_from_array_init (decl, init);
 	  /* And complain about multiple initializers.  */
diff --git a/gcc/cp/lambda.c b/gcc/cp/lambda.c
index 297327f..318671b 100644
--- a/gcc/cp/lambda.c
+++ b/gcc/cp/lambda.c
@@ -262,6 +262,7 @@ is_capture_proxy (tree decl)
 	  && DECL_HAS_VALUE_EXPR_P (decl)
 	  && !DECL_ANON_UNION_VAR_P (decl)
 	  && !DECL_DECOMPOSITION_P (decl)
+	  && !DECL_FNAME_P (decl)
 	  && LAMBDA_FUNCTION_P (DECL_CONTEXT (decl)));
 }
 
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index fc6cf9895..2dc0cb1 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -16735,6 +16735,10 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
 	    register_local_specialization (inst, decl);
 	    break;
 	  }
+	else if (DECL_PRETTY_FUNCTION_P (decl))
+	  decl = make_fname_decl (DECL_SOURCE_LOCATION (decl),
+				  DECL_NAME (decl),
+				  true/*DECL_PRETTY_FUNCTION_P (decl)*/);
 	else if (DECL_IMPLICIT_TYPEDEF_P (decl)
 		 && LAMBDA_TYPE_P (TREE_TYPE (decl)))
 	  /* Don't copy the old closure; we'll create a new one in
@@ -16793,17 +16797,7 @@ tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
 						   complain, in_decl, &first,
 						   &cnt);
 
-		    if (VAR_P (decl)
-			&& DECL_PRETTY_FUNCTION_P (decl))
-		      {
-			/* For __PRETTY_FUNCTION__ we have to adjust the
-			   initializer.  */
-			const char *const name
-			  = cxx_printable_name (current_function_decl, 2);
-			init = cp_fname_init (name, &TREE_TYPE (decl));
-		      }
-		    else
-		      init = tsubst_init (init, decl, args, complain, in_decl);
+		    init = tsubst_init (init, decl, args, complain, in_decl);
 
 		    if (VAR_P (decl))
 		      const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P