Add gcc-4.6. Synced to @180989

Change-Id: Ie3676586e1d8e3c8cd9f07d022f450d05fa08439
svn://gcc.gnu.org/svn/gcc/branches/google/gcc-4_6-mobile

1 files changed, 437 insertions, 0 deletions

diff --git a/gcc-4.6/gcc/cp/optimize.c b/gcc-4.6/gcc/cp/optimize.c
new file mode 100644
index 000000000..2ce9838a7
--- /dev/null
+++ b/gcc-4.6/gcc/cp/optimize.c
@@ -0,0 +1,437 @@
+/* Perform optimizations on tree structure.
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2007, 2008, 2009,
+   2010 Free Software Foundation, Inc.
+   Written by Mark Michell (mark@codesourcery.com).
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "cp-tree.h"
+#include "input.h"
+#include "params.h"
+#include "hashtab.h"
+#include "target.h"
+#include "debug.h"
+#include "tree-inline.h"
+#include "flags.h"
+#include "langhooks.h"
+#include "diagnostic-core.h"
+#include "tree-dump.h"
+#include "gimple.h"
+#include "tree-iterator.h"
+#include "cgraph.h"
+
+/* Prototypes.  */
+
+static void update_cloned_parm (tree, tree, bool);
+
+/* CLONED_PARM is a copy of CLONE, generated for a cloned constructor
+   or destructor.  Update it to ensure that the source-position for
+   the cloned parameter matches that for the original, and that the
+   debugging generation code will be able to find the original PARM.  */
+
+static void
+update_cloned_parm (tree parm, tree cloned_parm, bool first)
+{
+  DECL_ABSTRACT_ORIGIN (cloned_parm) = parm;
+
+  /* We may have taken its address.  */
+  TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm);
+
+  /* The definition might have different constness.  */
+  TREE_READONLY (cloned_parm) = TREE_READONLY (parm);
+
+  TREE_USED (cloned_parm) = !first || TREE_USED (parm);
+
+  /* The name may have changed from the declaration.  */
+  DECL_NAME (cloned_parm) = DECL_NAME (parm);
+  DECL_SOURCE_LOCATION (cloned_parm) = DECL_SOURCE_LOCATION (parm);
+  TREE_TYPE (cloned_parm) = TREE_TYPE (parm);
+
+  DECL_GIMPLE_REG_P (cloned_parm) = DECL_GIMPLE_REG_P (parm);
+}
+
+
+/* FN is a function in High GIMPLE form that has a complete body and no
+   CFG.  CLONE is a function whose body is to be set to a copy of FN,
+   mapping argument declarations according to the ARG_MAP splay_tree.  */
+
+static void
+clone_body (tree clone, tree fn, void *arg_map)
+{
+  copy_body_data id;
+  tree stmts;
+
+  /* Clone the body, as if we were making an inline call.  But, remap
+     the parameters in the callee to the parameters of caller.  */
+  memset (&id, 0, sizeof (id));
+  id.src_fn = fn;
+  id.dst_fn = clone;
+  id.src_cfun = DECL_STRUCT_FUNCTION (fn);
+  id.decl_map = (struct pointer_map_t *) arg_map;
+
+  id.copy_decl = copy_decl_no_change;
+  id.transform_call_graph_edges = CB_CGE_DUPLICATE;
+  id.transform_new_cfg = true;
+  id.transform_return_to_modify = false;
+  id.transform_lang_insert_block = NULL;
+
+  /* We're not inside any EH region.  */
+  id.eh_lp_nr = 0;
+
+  stmts = DECL_SAVED_TREE (fn);
+  walk_tree (&stmts, copy_tree_body_r, &id, NULL);
+
+  /* Also remap the initializer of any static variables so that they (in
+     particular, any label addresses) correspond to the base variant rather
+     than the abstract one.  */
+  if (DECL_NAME (clone) == base_dtor_identifier
+      || DECL_NAME (clone) == base_ctor_identifier)
+    {
+      unsigned ix;
+      tree decl;
+
+      FOR_EACH_LOCAL_DECL (DECL_STRUCT_FUNCTION (fn), ix, decl)
+        walk_tree (&DECL_INITIAL (decl), copy_tree_body_r, &id, NULL);
+    }
+
+  append_to_statement_list_force (stmts, &DECL_SAVED_TREE (clone));
+}
+
+/* DELETE_DTOR is a delete destructor whose body will be built.
+   COMPLETE_DTOR is the corresponding complete destructor.  */
+
+static void
+build_delete_destructor_body (tree delete_dtor, tree complete_dtor)
+{
+  tree call_dtor, call_delete;
+  tree parm = DECL_ARGUMENTS (delete_dtor);
+  tree virtual_size = cxx_sizeof (current_class_type);
+
+  /* Call the corresponding complete destructor.  */
+  gcc_assert (complete_dtor);
+  call_dtor = build_cxx_call (complete_dtor, 1, &parm);
+  add_stmt (call_dtor);
+
+  add_stmt (build_stmt (0, LABEL_EXPR, cdtor_label));
+
+  /* Call the delete function.  */
+  call_delete = build_op_delete_call (DELETE_EXPR, current_class_ptr,
+                                      virtual_size,
+                                      /*global_p=*/false,
+                                      /*placement=*/NULL_TREE,
+                                      /*alloc_fn=*/NULL_TREE);
+  add_stmt (call_delete);
+
+  /* Return the address of the object.  */
+  if (targetm.cxx.cdtor_returns_this ())
+    {
+      tree val = DECL_ARGUMENTS (delete_dtor);
+      val = build2 (MODIFY_EXPR, TREE_TYPE (val),
+                    DECL_RESULT (delete_dtor), val);
+      add_stmt (build_stmt (0, RETURN_EXPR, val));
+    }
+}
+
+/* Return name of comdat group for complete and base ctor (or dtor)
+   that have the same body.  If dtor is virtual, deleting dtor goes
+   into this comdat group as well.  */
+
+static tree
+cdtor_comdat_group (tree complete, tree base)
+{
+  tree complete_name = DECL_COMDAT_GROUP (complete);
+  tree base_name = DECL_COMDAT_GROUP (base);
+  char *grp_name;
+  const char *p, *q;
+  bool diff_seen = false;
+  size_t idx;
+  if (complete_name == NULL)
+    complete_name = cxx_comdat_group (complete);
+  if (base_name == NULL)
+    base_name = cxx_comdat_group (base);
+  gcc_assert (IDENTIFIER_LENGTH (complete_name)
+	      == IDENTIFIER_LENGTH (base_name));
+  grp_name = XALLOCAVEC (char, IDENTIFIER_LENGTH (complete_name) + 1);
+  p = IDENTIFIER_POINTER (complete_name);
+  q = IDENTIFIER_POINTER (base_name);
+  for (idx = 0; idx < IDENTIFIER_LENGTH (complete_name); idx++)
+    if (p[idx] == q[idx])
+      grp_name[idx] = p[idx];
+    else
+      {
+	gcc_assert (!diff_seen
+		    && idx > 0
+		    && (p[idx - 1] == 'C' || p[idx - 1] == 'D')
+		    && p[idx] == '1'
+		    && q[idx] == '2');
+	grp_name[idx] = '5';
+	diff_seen = true;
+      }
+  grp_name[idx] = '\0';
+  gcc_assert (diff_seen);
+  return get_identifier (grp_name);
+}
+
+/* FN is a function that has a complete body.  Clone the body as
+   necessary.  Returns nonzero if there's no longer any need to
+   process the main body.  */
+
+bool
+maybe_clone_body (tree fn)
+{
+  tree comdat_group = NULL_TREE;
+  tree clone;
+  tree fns[3];
+  bool first = true;
+  bool in_charge_parm_used;
+  int idx;
+  bool need_alias = false;
+
+  /* We only clone constructors and destructors.  */
+  if (!DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)
+      && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn))
+    return 0;
+
+  /* Emit the DWARF1 abstract instance.  */
+  (*debug_hooks->deferred_inline_function) (fn);
+
+  in_charge_parm_used = CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fn)) != NULL;
+  fns[0] = NULL_TREE;
+  fns[1] = NULL_TREE;
+  fns[2] = NULL_TREE;
+
+  /* Look for the complete destructor which may be used to build the
+     delete destructor.  */
+  FOR_EACH_CLONE (clone, fn)
+    if (DECL_NAME (clone) == complete_dtor_identifier
+	|| DECL_NAME (clone) == complete_ctor_identifier)
+      fns[1] = clone;
+    else if (DECL_NAME (clone) == base_dtor_identifier
+	     || DECL_NAME (clone) == base_ctor_identifier)
+      fns[0] = clone;
+    else if (DECL_NAME (clone) == deleting_dtor_identifier)
+      fns[2] = clone;
+    else
+      gcc_unreachable ();
+
+  /* Remember if we can't have multiple clones for some reason.  We need to
+     check this before we remap local static initializers in clone_body.  */
+  if (!tree_versionable_function_p (fn))
+    need_alias = true;
+
+  /* We know that any clones immediately follow FN in the TYPE_METHODS
+     list.  */
+  push_to_top_level ();
+  for (idx = 0; idx < 3; idx++)
+    {
+      tree parm;
+      tree clone_parm;
+      int parmno;
+      bool alias = false;
+      struct pointer_map_t *decl_map;
+
+      clone = fns[idx];
+      if (!clone)
+	continue;      
+
+      /* Update CLONE's source position information to match FN's.  */
+      DECL_SOURCE_LOCATION (clone) = DECL_SOURCE_LOCATION (fn);
+      DECL_DECLARED_INLINE_P (clone) = DECL_DECLARED_INLINE_P (fn);
+      DECL_DECLARED_CONSTEXPR_P (clone) = DECL_DECLARED_CONSTEXPR_P (fn);
+      DECL_COMDAT (clone) = DECL_COMDAT (fn);
+      DECL_WEAK (clone) = DECL_WEAK (fn);
+
+      /* We don't copy the comdat group from fn to clone because the assembler
+	 name of fn was corrupted by write_mangled_name by adding *INTERNAL*
+	 to it. By doing so, it also corrupted the comdat group. */
+      if (DECL_ONE_ONLY (fn))
+	DECL_COMDAT_GROUP (clone) = cxx_comdat_group (clone);
+      DECL_SECTION_NAME (clone) = DECL_SECTION_NAME (fn);
+      DECL_USE_TEMPLATE (clone) = DECL_USE_TEMPLATE (fn);
+      DECL_EXTERNAL (clone) = DECL_EXTERNAL (fn);
+      DECL_INTERFACE_KNOWN (clone) = DECL_INTERFACE_KNOWN (fn);
+      DECL_NOT_REALLY_EXTERN (clone) = DECL_NOT_REALLY_EXTERN (fn);
+      TREE_PUBLIC (clone) = TREE_PUBLIC (fn);
+      DECL_VISIBILITY (clone) = DECL_VISIBILITY (fn);
+      DECL_VISIBILITY_SPECIFIED (clone) = DECL_VISIBILITY_SPECIFIED (fn);
+      DECL_DLLIMPORT_P (clone) = DECL_DLLIMPORT_P (fn);
+      DECL_ATTRIBUTES (clone) = copy_list (DECL_ATTRIBUTES (fn));
+      DECL_DISREGARD_INLINE_LIMITS (clone) = DECL_DISREGARD_INLINE_LIMITS (fn);
+
+      /* Adjust the parameter names and locations.  */
+      parm = DECL_ARGUMENTS (fn);
+      clone_parm = DECL_ARGUMENTS (clone);
+      /* Update the `this' parameter, which is always first.  */
+      update_cloned_parm (parm, clone_parm, first);
+      parm = DECL_CHAIN (parm);
+      clone_parm = DECL_CHAIN (clone_parm);
+      if (DECL_HAS_IN_CHARGE_PARM_P (fn))
+	parm = DECL_CHAIN (parm);
+      if (DECL_HAS_VTT_PARM_P (fn))
+	parm = DECL_CHAIN (parm);
+      if (DECL_HAS_VTT_PARM_P (clone))
+	clone_parm = DECL_CHAIN (clone_parm);
+      for (; parm;
+	   parm = DECL_CHAIN (parm), clone_parm = DECL_CHAIN (clone_parm))
+	/* Update this parameter.  */
+	update_cloned_parm (parm, clone_parm, first);
+
+      /* Start processing the function.  */
+      start_preparsed_function (clone, NULL_TREE, SF_PRE_PARSED);
+
+      /* Tell cgraph if both ctors or both dtors are known to have
+	 the same body.  */
+      if (!in_charge_parm_used
+	  && fns[0]
+	  && idx == 1
+	  && !flag_use_repository
+	  && DECL_INTERFACE_KNOWN (fns[0])
+	  && (SUPPORTS_ONE_ONLY || !DECL_WEAK (fns[0]))
+	  && (!DECL_ONE_ONLY (fns[0])
+	      || (HAVE_COMDAT_GROUP
+		  && DECL_WEAK (fns[0])))
+	  && cgraph_same_body_alias (cgraph_node (fns[0]), clone, fns[0]))
+	{
+	  alias = true;
+	  if (DECL_ONE_ONLY (fns[0]))
+	    {
+	      /* For comdat base and complete cdtors put them
+		 into the same, *[CD]5* comdat group instead of
+		 *[CD][12]*.  */
+	      comdat_group = cdtor_comdat_group (fns[1], fns[0]);
+	      DECL_COMDAT_GROUP (fns[0]) = comdat_group;
+	    }
+	}
+
+      /* Build the delete destructor by calling complete destructor
+         and delete function.  */
+      if (idx == 2)
+	build_delete_destructor_body (clone, fns[1]);
+      else if (alias)
+	/* No need to populate body.  */ ;
+      else
+	{
+	  /* If we can't have multiple copies of FN (say, because there's a
+	     static local initialized with the address of a label), we need
+	     to use an alias for the complete variant.  */
+	  if (idx == 1 && need_alias)
+	    {
+	      if (DECL_STRUCT_FUNCTION (fn)->cannot_be_copied_set)
+		sorry (DECL_STRUCT_FUNCTION (fn)->cannot_be_copied_reason, fn);
+	      else
+		sorry ("making multiple clones of %qD", fn);
+	    }
+
+          /* Remap the parameters.  */
+          decl_map = pointer_map_create ();
+          for (parmno = 0,
+                parm = DECL_ARGUMENTS (fn),
+                clone_parm = DECL_ARGUMENTS (clone);
+              parm;
+              ++parmno,
+                parm = DECL_CHAIN (parm))
+            {
+              /* Map the in-charge parameter to an appropriate constant.  */
+              if (DECL_HAS_IN_CHARGE_PARM_P (fn) && parmno == 1)
+                {
+                  tree in_charge;
+                  in_charge = in_charge_arg_for_name (DECL_NAME (clone));
+                  *pointer_map_insert (decl_map, parm) = in_charge;
+                }
+              else if (DECL_ARTIFICIAL (parm)
+                       && DECL_NAME (parm) == vtt_parm_identifier)
+                {
+                  /* For a subobject constructor or destructor, the next
+                     argument is the VTT parameter.  Remap the VTT_PARM
+                     from the CLONE to this parameter.  */
+                  if (DECL_HAS_VTT_PARM_P (clone))
+                    {
+                      DECL_ABSTRACT_ORIGIN (clone_parm) = parm;
+                      *pointer_map_insert (decl_map, parm) = clone_parm;
+                      clone_parm = DECL_CHAIN (clone_parm);
+                    }
+                  /* Otherwise, map the VTT parameter to `NULL'.  */
+                  else
+                    *pointer_map_insert (decl_map, parm)
+                       = fold_convert (TREE_TYPE (parm), null_pointer_node);
+                }
+              /* Map other parameters to their equivalents in the cloned
+                 function.  */
+              else
+                {
+                  *pointer_map_insert (decl_map, parm) = clone_parm;
+                  clone_parm = DECL_CHAIN (clone_parm);
+                }
+            }
+
+          if (targetm.cxx.cdtor_returns_this ())
+            {
+              parm = DECL_RESULT (fn);
+              clone_parm = DECL_RESULT (clone);
+              *pointer_map_insert (decl_map, parm) = clone_parm;
+            }
+
+          /* Clone the body.  */
+          clone_body (clone, fn, decl_map);
+
+          /* Clean up.  */
+          pointer_map_destroy (decl_map);
+        }
+
+      /* The clone can throw iff the original function can throw.  */
+      cp_function_chain->can_throw = !TREE_NOTHROW (fn);
+
+      /* Now, expand this function into RTL, if appropriate.  */
+      finish_function (0);
+      BLOCK_ABSTRACT_ORIGIN (DECL_INITIAL (clone)) = DECL_INITIAL (fn);
+      if (alias)
+	{
+	  if (expand_or_defer_fn_1 (clone))
+	    emit_associated_thunks (clone);
+	}
+      else
+	expand_or_defer_fn (clone);
+      first = false;
+    }
+  pop_from_top_level ();
+
+  if (comdat_group)
+    {
+      DECL_COMDAT_GROUP (fns[1]) = comdat_group;
+      if (fns[2])
+	{
+	  struct cgraph_node *base_dtor_node, *deleting_dtor_node;
+	  /* If *[CD][12]* dtors go into the *[CD]5* comdat group and dtor is
+	     virtual, it goes into the same comdat group as well.  */
+	  DECL_COMDAT_GROUP (fns[2]) = comdat_group;
+	  base_dtor_node = cgraph_node (fns[0]);
+	  deleting_dtor_node = cgraph_node (fns[2]);
+	  gcc_assert (base_dtor_node->same_comdat_group == NULL);
+	  gcc_assert (deleting_dtor_node->same_comdat_group == NULL);
+	  base_dtor_node->same_comdat_group = deleting_dtor_node;
+	  deleting_dtor_node->same_comdat_group = base_dtor_node;
+	}
+    }
+
+  /* We don't need to process the original function any further.  */
+  return 1;
+}