[Patch, Fortran] PR50640, PR51207 - fix select_type_12

[Tobias Burnus]

The patch in class.c for PR50640 makes the default initializer 
("__def_init_)TREE_READONLY. I also set attr.subroutine for __copy_, 
which is not needed but its lacking irritated me once when stepping 
through trans*.c.

The patch in trans-decl.c/trans.h fixes a 4.7 regressions (P1), which 
causes gfortran.dg/select_type_12.f03 to fail. The actual regression is 
due to a middle-end change, but it can be easier fixed on the front-end 
side. The problem occurs for a derived type that is declared in a 
procedure, but only used in a nested procedure. The vtable is 
consequently generated in the scope of the parent procedure.

As Michael suggested, a solution is to place the vtable at the top 
level. However, that is not sufficient, one also needs to place the 
default member function __copy_<dt name> in the top level as its address 
is used in the vtable. Fortunately, user type-bound procedures are only 
allowed for derived-types declared in the specification part of a 
module. Hence, those are by construction in the toplevel.

The patch has been bootstrapped and regtested on x86-64-linux.
OK for the trunk?

Tobias

PS: I see the following unrelated test-suite failures:
- gfortran.fortran-torture/execute/arrayarg.f90 (PR middle-end/51134, 
memset is misoptimized, P1 [4.7], wrong-code)
- gfortran.fortran-torture/execute/entry_4.f90 (PR middle-end/50628, P1 
[4.7], wrong-code)
- gfortran.dg/realloc_on_assign_5.f03 (PR fortran/47674, wrong-code)
2011-11-18  Tobias Burnus  <bur...@net-b.de>

	PR fortran/51207
	* class.c (gfc_find_derived_vtab): Mark __def_init as PARAMETER
	and hence as TREE_READONLY; add subroutine attribute to
	__copy_ procedure.

	PR fortran/50640
	* trans.h (GFC_DECL_PUSH_TOPLEVEL): New DECL_LANG_FLAG_7.
	* trans-decl.c (gfc_get_symbol_decl): Mark __def_init and vtab as
	GFC_DECL_PUSH_TOPLEVEL.
	(gfc_generate_function_code): If GFC_DECL_PUSH_TOPLEVEL, push it there.
	(build_function_decl): Push __copy_ procedure to the toplevel.


diff --git a/gcc/fortran/class.c b/gcc/fortran/class.c
index dc76ad1..bcb2d0b 100644
--- a/gcc/fortran/class.c
+++ b/gcc/fortran/class.c
@@ -522,7 +522,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 		  def_init->attr.target = 1;
 		  def_init->attr.save = SAVE_IMPLICIT;
 		  def_init->attr.access = ACCESS_PUBLIC;
-		  def_init->attr.flavor = FL_VARIABLE;
+		  def_init->attr.flavor = FL_PARAMETER;
 		  gfc_set_sym_referenced (def_init);
 		  def_init->ts.type = BT_DERIVED;
 		  def_init->ts.u.derived = derived;
@@ -552,6 +552,7 @@ gfc_find_derived_vtab (gfc_symbol *derived)
 		  gfc_get_symbol (name, sub_ns, &copy);
 		  sub_ns->proc_name = copy;
 		  copy->attr.flavor = FL_PROCEDURE;
+		  copy->attr.subroutine = 1;
 		  copy->attr.if_source = IFSRC_DECL;
 		  if (ns->proc_name->attr.flavor == FL_MODULE)
 		    copy->module = ns->proc_name->name;
diff --git a/gcc/fortran/trans-decl.c b/gcc/fortran/trans-decl.c
index 02c0ed7..fc8a9ed 100644
--- a/gcc/fortran/trans-decl.c
+++ b/gcc/fortran/trans-decl.c
@@ -1471,6 +1471,10 @@ gfc_get_symbol_decl (gfc_symbol * sym)
       && !sym->attr.proc_pointer)
     DECL_BY_REFERENCE (decl) = 1;
 
+  if (sym->attr.vtab
+      || (sym->name[0] == '_' && strncmp ("__def_init", sym->name, 10) == 0))
+    GFC_DECL_PUSH_TOPLEVEL (decl) = 1;
+
   return decl;
 }
 
@@ -1891,7 +1895,8 @@ build_function_decl (gfc_symbol * sym, bool global)
   /* Layout the function declaration and put it in the binding level
      of the current function.  */
 
-  if (global)
+  if (global
+      || (sym->name[0] == '_' && strncmp ("__copy", sym->name, 6) == 0))
     pushdecl_top_level (fndecl);
   else
     pushdecl (fndecl);
@@ -5316,7 +5321,10 @@ gfc_generate_function_code (gfc_namespace * ns)
 
       next = DECL_CHAIN (decl);
       DECL_CHAIN (decl) = NULL_TREE;
-      pushdecl (decl);
+      if (GFC_DECL_PUSH_TOPLEVEL (decl))
+	pushdecl_top_level (decl);
+      else
+	pushdecl (decl);
       decl = next;
     }
   saved_function_decls = NULL_TREE;
diff --git a/gcc/fortran/trans.h b/gcc/fortran/trans.h
index 22033d3..8fc7599 100644
--- a/gcc/fortran/trans.h
+++ b/gcc/fortran/trans.h
@@ -802,6 +802,7 @@ struct GTY((variable_size)) lang_decl {
 #define GFC_DECL_CRAY_POINTEE(node) DECL_LANG_FLAG_4(node)
 #define GFC_DECL_RESULT(node) DECL_LANG_FLAG_5(node)
 #define GFC_DECL_SUBREF_ARRAY_P(node) DECL_LANG_FLAG_6(node)
+#define GFC_DECL_PUSH_TOPLEVEL(node) DECL_LANG_FLAG_7(node)
 
 /* An array descriptor.  */
 #define GFC_DESCRIPTOR_TYPE_P(node) TYPE_LANG_FLAG_1(node)