Reorganize the gcc vendor import work area. This flattens out a bunch

of unnecessary path components that are relics of cvs2svn.

(These are directory moves)

1 files changed, 1990 insertions, 0 deletions

diff --git a/gcc/tree-nested.c b/gcc/tree-nested.c
new file mode 100644
index 0000000..06fbbc9
--- /dev/null
+++ b/gcc/tree-nested.c
@@ -0,0 +1,1990 @@
+/* Nested function decomposition for trees.
+   Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
+
+   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 2, 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 COPYING.  If not, write to
+   the Free Software Foundation, 51 Franklin Street, Fifth Floor,
+   Boston, MA 02110-1301, USA.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "tm.h"
+#include "tree.h"
+#include "rtl.h"
+#include "tm_p.h"
+#include "function.h"
+#include "tree-dump.h"
+#include "tree-inline.h"
+#include "tree-gimple.h"
+#include "tree-iterator.h"
+#include "tree-flow.h"
+#include "cgraph.h"
+#include "expr.h"
+#include "langhooks.h"
+#include "ggc.h"
+
+
+/* The object of this pass is to lower the representation of a set of nested
+   functions in order to expose all of the gory details of the various
+   nonlocal references.  We want to do this sooner rather than later, in
+   order to give us more freedom in emitting all of the functions in question.
+
+   Back in olden times, when gcc was young, we developed an insanely 
+   complicated scheme whereby variables which were referenced nonlocally
+   were forced to live in the stack of the declaring function, and then
+   the nested functions magically discovered where these variables were
+   placed.  In order for this scheme to function properly, it required
+   that the outer function be partially expanded, then we switch to 
+   compiling the inner function, and once done with those we switch back
+   to compiling the outer function.  Such delicate ordering requirements
+   makes it difficult to do whole translation unit optimizations 
+   involving such functions.
+
+   The implementation here is much more direct.  Everything that can be
+   referenced by an inner function is a member of an explicitly created
+   structure herein called the "nonlocal frame struct".  The incoming
+   static chain for a nested function is a pointer to this struct in 
+   the parent.  In this way, we settle on known offsets from a known
+   base, and so are decoupled from the logic that places objects in the
+   function's stack frame.  More importantly, we don't have to wait for
+   that to happen -- since the compilation of the inner function is no
+   longer tied to a real stack frame, the nonlocal frame struct can be
+   allocated anywhere.  Which means that the outer function is now
+   inlinable.
+
+   Theory of operation here is very simple.  Iterate over all the 
+   statements in all the functions (depth first) several times, 
+   allocating structures and fields on demand.  In general we want to
+   examine inner functions first, so that we can avoid making changes
+   to outer functions which are unnecessary.
+
+   The order of the passes matters a bit, in that later passes will be
+   skipped if it is discovered that the functions don't actually interact
+   at all.  That is, they're nested in the lexical sense but could have
+   been written as independent functions without change.  */
+
+
+struct var_map_elt GTY(())
+{
+  tree old;
+  tree new;
+};
+
+struct nesting_info GTY ((chain_next ("%h.next")))
+{
+  struct nesting_info *outer;
+  struct nesting_info *inner;
+  struct nesting_info *next;
+  
+  htab_t GTY ((param_is (struct var_map_elt))) field_map;
+  htab_t GTY ((param_is (struct var_map_elt))) var_map;
+  bitmap suppress_expansion;
+
+  tree context;
+  tree new_local_var_chain;
+  tree debug_var_chain;
+  tree frame_type;
+  tree frame_decl;
+  tree chain_field;
+  tree chain_decl;
+  tree nl_goto_field;
+
+  bool any_parm_remapped;
+  bool any_tramp_created;
+  char static_chain_added;
+};
+
+
+/* Hashing and equality functions for nesting_info->var_map.  */
+
+static hashval_t
+var_map_hash (const void *x)
+{
+  const struct var_map_elt *a = (const struct var_map_elt *) x;
+  return htab_hash_pointer (a->old);
+}
+
+static int
+var_map_eq (const void *x, const void *y)
+{
+  const struct var_map_elt *a = (const struct var_map_elt *) x;
+  const struct var_map_elt *b = (const struct var_map_elt *) y;
+  return a->old == b->old;
+}
+
+/* We're working in so many different function contexts simultaneously,
+   that create_tmp_var is dangerous.  Prevent mishap.  */
+#define create_tmp_var cant_use_create_tmp_var_here_dummy
+
+/* Like create_tmp_var, except record the variable for registration at
+   the given nesting level.  */
+
+static tree
+create_tmp_var_for (struct nesting_info *info, tree type, const char *prefix)
+{
+  tree tmp_var;
+
+  /* If the type is of variable size or a type which must be created by the
+     frontend, something is wrong.  Note that we explicitly allow
+     incomplete types here, since we create them ourselves here.  */
+  gcc_assert (!TREE_ADDRESSABLE (type));
+  gcc_assert (!TYPE_SIZE_UNIT (type)
+	      || TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST);
+
+  tmp_var = create_tmp_var_raw (type, prefix);
+  DECL_CONTEXT (tmp_var) = info->context;
+  TREE_CHAIN (tmp_var) = info->new_local_var_chain;
+  DECL_SEEN_IN_BIND_EXPR_P (tmp_var) = 1;
+  if (TREE_CODE (type) == COMPLEX_TYPE)
+    DECL_COMPLEX_GIMPLE_REG_P (tmp_var) = 1;
+
+  info->new_local_var_chain = tmp_var;
+
+  return tmp_var;
+}
+
+/* Take the address of EXP to be used within function CONTEXT.
+   Mark it for addressability as necessary.  */
+
+tree
+build_addr (tree exp, tree context)
+{
+  tree base = exp;
+  tree save_context;
+  tree retval;
+
+  while (handled_component_p (base))
+    base = TREE_OPERAND (base, 0);
+
+  if (DECL_P (base))
+    TREE_ADDRESSABLE (base) = 1;
+
+  /* Building the ADDR_EXPR will compute a set of properties for
+     that ADDR_EXPR.  Those properties are unfortunately context
+     specific.  ie, they are dependent on CURRENT_FUNCTION_DECL.
+
+     Temporarily set CURRENT_FUNCTION_DECL to the desired context,
+     build the ADDR_EXPR, then restore CURRENT_FUNCTION_DECL.  That
+     way the properties are for the ADDR_EXPR are computed properly.  */
+  save_context = current_function_decl;
+  current_function_decl = context;
+  retval = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
+  current_function_decl = save_context;;
+  return retval;
+}
+
+/* Insert FIELD into TYPE, sorted by alignment requirements.  */
+
+void
+insert_field_into_struct (tree type, tree field)
+{
+  tree *p;
+
+  DECL_CONTEXT (field) = type;
+
+  for (p = &TYPE_FIELDS (type); *p ; p = &TREE_CHAIN (*p))
+    if (DECL_ALIGN (field) >= DECL_ALIGN (*p))
+      break;
+
+  TREE_CHAIN (field) = *p;
+  *p = field;
+}
+
+/* Build or return the RECORD_TYPE that describes the frame state that is
+   shared between INFO->CONTEXT and its nested functions.  This record will
+   not be complete until finalize_nesting_tree; up until that point we'll
+   be adding fields as necessary.
+
+   We also build the DECL that represents this frame in the function.  */
+
+static tree
+get_frame_type (struct nesting_info *info)
+{
+  tree type = info->frame_type;
+  if (!type)
+    {
+      char *name;
+
+      type = make_node (RECORD_TYPE);
+
+      name = concat ("FRAME.",
+		     IDENTIFIER_POINTER (DECL_NAME (info->context)),
+		     NULL);
+      TYPE_NAME (type) = get_identifier (name);
+      free (name);
+
+      info->frame_type = type;
+      info->frame_decl = create_tmp_var_for (info, type, "FRAME");
+
+      /* ??? Always make it addressable for now, since it is meant to
+	 be pointed to by the static chain pointer.  This pessimizes
+	 when it turns out that no static chains are needed because
+	 the nested functions referencing non-local variables are not
+	 reachable, but the true pessimization is to create the non-
+	 local frame structure in the first place.  */
+      TREE_ADDRESSABLE (info->frame_decl) = 1;
+    }
+  return type;
+}
+
+/* Return true if DECL should be referenced by pointer in the non-local
+   frame structure.  */
+
+static bool
+use_pointer_in_frame (tree decl)
+{
+  if (TREE_CODE (decl) == PARM_DECL)
+    {
+      /* It's illegal to copy TREE_ADDRESSABLE, impossible to copy variable
+         sized decls, and inefficient to copy large aggregates.  Don't bother
+         moving anything but scalar variables.  */
+      return AGGREGATE_TYPE_P (TREE_TYPE (decl));
+    }
+  else
+    {
+      /* Variable sized types make things "interesting" in the frame.  */
+      return DECL_SIZE (decl) == NULL || !TREE_CONSTANT (DECL_SIZE (decl));
+    }
+}
+
+/* Given DECL, a non-locally accessed variable, find or create a field
+   in the non-local frame structure for the given nesting context.  */
+
+static tree
+lookup_field_for_decl (struct nesting_info *info, tree decl,
+		       enum insert_option insert)
+{
+  struct var_map_elt *elt, dummy;
+  void **slot;
+  tree field;
+
+  dummy.old = decl;
+  slot = htab_find_slot (info->field_map, &dummy, insert);
+  if (!slot)
+    {
+      gcc_assert (insert != INSERT);
+      return NULL;
+    }
+  elt = (struct var_map_elt *) *slot;
+
+  if (!elt && insert == INSERT)
+    {
+      field = make_node (FIELD_DECL);
+      DECL_NAME (field) = DECL_NAME (decl);
+
+      if (use_pointer_in_frame (decl))
+	{
+	  TREE_TYPE (field) = build_pointer_type (TREE_TYPE (decl));
+	  DECL_ALIGN (field) = TYPE_ALIGN (TREE_TYPE (field));
+	  DECL_NONADDRESSABLE_P (field) = 1;
+	}
+      else
+	{
+          TREE_TYPE (field) = TREE_TYPE (decl);
+          DECL_SOURCE_LOCATION (field) = DECL_SOURCE_LOCATION (decl);
+          DECL_ALIGN (field) = DECL_ALIGN (decl);
+          DECL_USER_ALIGN (field) = DECL_USER_ALIGN (decl);
+          TREE_ADDRESSABLE (field) = TREE_ADDRESSABLE (decl);
+          DECL_NONADDRESSABLE_P (field) = !TREE_ADDRESSABLE (decl);
+          TREE_THIS_VOLATILE (field) = TREE_THIS_VOLATILE (decl);
+	}
+
+      insert_field_into_struct (get_frame_type (info), field);
+  
+      elt = GGC_NEW (struct var_map_elt);
+      elt->old = decl;
+      elt->new = field;
+      *slot = elt;
+
+      if (TREE_CODE (decl) == PARM_DECL)
+	info->any_parm_remapped = true;
+    }
+  else
+    field = elt ? elt->new : NULL;
+
+  return field;
+}
+
+/* Build or return the variable that holds the static chain within
+   INFO->CONTEXT.  This variable may only be used within INFO->CONTEXT.  */
+
+static tree
+get_chain_decl (struct nesting_info *info)
+{
+  tree decl = info->chain_decl;
+  if (!decl)
+    {
+      tree type;
+
+      type = get_frame_type (info->outer);
+      type = build_pointer_type (type);
+
+      /* Note that this variable is *not* entered into any BIND_EXPR;
+	 the construction of this variable is handled specially in
+	 expand_function_start and initialize_inlined_parameters.
+	 Note also that it's represented as a parameter.  This is more
+	 close to the truth, since the initial value does come from 
+	 the caller.  */
+      decl = build_decl (PARM_DECL, create_tmp_var_name ("CHAIN"), type);
+      DECL_ARTIFICIAL (decl) = 1;
+      DECL_IGNORED_P (decl) = 1;
+      TREE_USED (decl) = 1;
+      DECL_CONTEXT (decl) = info->context;
+      DECL_ARG_TYPE (decl) = type;
+
+      /* Tell tree-inline.c that we never write to this variable, so
+	 it can copy-prop the replacement value immediately.  */
+      TREE_READONLY (decl) = 1;
+
+      info->chain_decl = decl;
+    }
+  return decl;
+}
+
+/* Build or return the field within the non-local frame state that holds
+   the static chain for INFO->CONTEXT.  This is the way to walk back up
+   multiple nesting levels.  */
+
+static tree
+get_chain_field (struct nesting_info *info)
+{
+  tree field = info->chain_field;
+  if (!field)
+    {
+      tree type = build_pointer_type (get_frame_type (info->outer));
+
+      field = make_node (FIELD_DECL);
+      DECL_NAME (field) = get_identifier ("__chain");
+      TREE_TYPE (field) = type;
+      DECL_ALIGN (field) = TYPE_ALIGN (type);
+      DECL_NONADDRESSABLE_P (field) = 1;
+
+      insert_field_into_struct (get_frame_type (info), field);
+
+      info->chain_field = field;
+    }
+  return field;
+}
+
+/* Copy EXP into a temporary.  Allocate the temporary in the context of
+   INFO and insert the initialization statement before TSI.  */
+
+static tree
+init_tmp_var (struct nesting_info *info, tree exp, tree_stmt_iterator *tsi)
+{
+  tree t, stmt;
+
+  t = create_tmp_var_for (info, TREE_TYPE (exp), NULL);
+  stmt = build2 (MODIFY_EXPR, TREE_TYPE (t), t, exp);
+  SET_EXPR_LOCUS (stmt, EXPR_LOCUS (tsi_stmt (*tsi)));
+  tsi_link_before (tsi, stmt, TSI_SAME_STMT);
+
+  return t;
+}
+
+/* Similarly, but only do so to force EXP to satisfy is_gimple_val.  */
+
+static tree
+tsi_gimplify_val (struct nesting_info *info, tree exp, tree_stmt_iterator *tsi)
+{
+  if (is_gimple_val (exp))
+    return exp;
+  else
+    return init_tmp_var (info, exp, tsi);
+}
+
+/* Similarly, but copy from the temporary and insert the statement
+   after the iterator.  */
+
+static tree
+save_tmp_var (struct nesting_info *info, tree exp,
+	      tree_stmt_iterator *tsi)
+{
+  tree t, stmt;
+
+  t = create_tmp_var_for (info, TREE_TYPE (exp), NULL);
+  stmt = build2 (MODIFY_EXPR, TREE_TYPE (t), exp, t);
+  SET_EXPR_LOCUS (stmt, EXPR_LOCUS (tsi_stmt (*tsi)));
+  tsi_link_after (tsi, stmt, TSI_SAME_STMT);
+
+  return t;
+}
+
+/* Build or return the type used to represent a nested function trampoline.  */
+
+static GTY(()) tree trampoline_type;
+
+static tree
+get_trampoline_type (void)
+{
+  tree record, t;
+  unsigned align, size;
+
+  if (trampoline_type)
+    return trampoline_type;
+
+  align = TRAMPOLINE_ALIGNMENT;
+  size = TRAMPOLINE_SIZE;
+
+  /* If we won't be able to guarantee alignment simply via TYPE_ALIGN,
+     then allocate extra space so that we can do dynamic alignment.  */
+  if (align > STACK_BOUNDARY)
+    {
+      size += ((align/BITS_PER_UNIT) - 1) & -(STACK_BOUNDARY/BITS_PER_UNIT);
+      align = STACK_BOUNDARY;
+    }
+
+  t = build_index_type (build_int_cst (NULL_TREE, size - 1));
+  t = build_array_type (char_type_node, t);
+  t = build_decl (FIELD_DECL, get_identifier ("__data"), t);
+  DECL_ALIGN (t) = align;
+  DECL_USER_ALIGN (t) = 1;
+
+  record = make_node (RECORD_TYPE);
+  TYPE_NAME (record) = get_identifier ("__builtin_trampoline");
+  TYPE_FIELDS (record) = t;
+  layout_type (record);
+
+  return record;
+}
+
+/* Given DECL, a nested function, find or create a field in the non-local
+   frame structure for a trampoline for this function.  */
+
+static tree
+lookup_tramp_for_decl (struct nesting_info *info, tree decl,
+		       enum insert_option insert)
+{
+  struct var_map_elt *elt, dummy;
+  void **slot;
+  tree field;
+
+  dummy.old = decl;
+  slot = htab_find_slot (info->var_map, &dummy, insert);
+  if (!slot)
+    {
+      gcc_assert (insert != INSERT);
+      return NULL;
+    }
+  elt = (struct var_map_elt *) *slot;
+
+  if (!elt && insert == INSERT)
+    {
+      field = make_node (FIELD_DECL);
+      DECL_NAME (field) = DECL_NAME (decl);
+      TREE_TYPE (field) = get_trampoline_type ();
+      TREE_ADDRESSABLE (field) = 1;
+
+      insert_field_into_struct (get_frame_type (info), field);
+
+      elt = GGC_NEW (struct var_map_elt);
+      elt->old = decl;
+      elt->new = field;
+      *slot = elt;
+
+      info->any_tramp_created = true;
+    }
+  else
+    field = elt ? elt->new : NULL;
+
+  return field;
+} 
+
+/* Build or return the field within the non-local frame state that holds
+   the non-local goto "jmp_buf".  The buffer itself is maintained by the
+   rtl middle-end as dynamic stack space is allocated.  */
+
+static tree
+get_nl_goto_field (struct nesting_info *info)
+{
+  tree field = info->nl_goto_field;
+  if (!field)
+    {
+      unsigned size;
+      tree type;
+
+      /* For __builtin_nonlocal_goto, we need N words.  The first is the
+	 frame pointer, the rest is for the target's stack pointer save
+	 area.  The number of words is controlled by STACK_SAVEAREA_MODE;
+	 not the best interface, but it'll do for now.  */
+      if (Pmode == ptr_mode)
+	type = ptr_type_node;
+      else
+	type = lang_hooks.types.type_for_mode (Pmode, 1);
+
+      size = GET_MODE_SIZE (STACK_SAVEAREA_MODE (SAVE_NONLOCAL));
+      size = size / GET_MODE_SIZE (Pmode);
+      size = size + 1;
+
+      type = build_array_type
+	(type, build_index_type (build_int_cst (NULL_TREE, size)));
+
+      field = make_node (FIELD_DECL);
+      DECL_NAME (field) = get_identifier ("__nl_goto_buf");
+      TREE_TYPE (field) = type;
+      DECL_ALIGN (field) = TYPE_ALIGN (type);
+      TREE_ADDRESSABLE (field) = 1;
+
+      insert_field_into_struct (get_frame_type (info), field);
+
+      info->nl_goto_field = field;
+    }
+
+  return field;
+}
+
+/* Helper function for walk_stmts.  Walk output operands of an ASM_EXPR.  */
+
+static void
+walk_asm_expr (struct walk_stmt_info *wi, tree stmt)
+{
+  int noutputs = list_length (ASM_OUTPUTS (stmt));
+  const char **oconstraints
+    = (const char **) alloca ((noutputs) * sizeof (const char *));
+  int i;
+  tree link;
+  const char *constraint;
+  bool allows_mem, allows_reg, is_inout;
+
+  wi->is_lhs = true;
+  for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link))
+    {
+      constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
+      oconstraints[i] = constraint;
+      parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
+			       &allows_reg, &is_inout);
+
+      wi->val_only = (allows_reg || !allows_mem);
+      walk_tree (&TREE_VALUE (link), wi->callback, wi, NULL);
+    }
+
+  for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
+    {
+      constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
+      parse_input_constraint (&constraint, 0, 0, noutputs, 0,
+			      oconstraints, &allows_mem, &allows_reg);
+
+      wi->val_only = (allows_reg || !allows_mem);
+      /* Although input "m" is not really a LHS, we need a lvalue.  */
+      wi->is_lhs = !wi->val_only;
+      walk_tree (&TREE_VALUE (link), wi->callback, wi, NULL);
+    }
+
+  wi->is_lhs = false;
+  wi->val_only = true;
+}
+
+/* Iterate over all sub-statements of *TP calling walk_tree with
+   WI->CALLBACK for every sub-expression in each statement found.  */
+
+void
+walk_stmts (struct walk_stmt_info *wi, tree *tp)
+{
+  tree t = *tp;
+  int walk_subtrees;
+
+  if (!t)
+    return;
+
+  if (wi->want_locations && EXPR_HAS_LOCATION (t))
+    input_location = EXPR_LOCATION (t);
+
+  switch (TREE_CODE (t))
+    {
+    case STATEMENT_LIST:
+      {
+	tree_stmt_iterator i;
+	for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
+	  {
+	    wi->tsi = i;
+	    walk_stmts (wi, tsi_stmt_ptr (i));
+	  }
+      }
+      break;
+
+    case COND_EXPR:
+      walk_tree (&COND_EXPR_COND (t), wi->callback, wi, NULL);
+      walk_stmts (wi, &COND_EXPR_THEN (t));
+      walk_stmts (wi, &COND_EXPR_ELSE (t));
+      break;
+    case CATCH_EXPR:
+      walk_stmts (wi, &CATCH_BODY (t));
+      break;
+    case EH_FILTER_EXPR:
+      walk_stmts (wi, &EH_FILTER_FAILURE (t));
+      break;
+    case TRY_CATCH_EXPR:
+    case TRY_FINALLY_EXPR:
+      walk_stmts (wi, &TREE_OPERAND (t, 0));
+      walk_stmts (wi, &TREE_OPERAND (t, 1));
+      break;
+
+    case BIND_EXPR:
+      if (wi->want_bind_expr)
+	{
+	  walk_subtrees = 1;
+	  wi->callback (tp, &walk_subtrees, wi);
+	  if (!walk_subtrees)
+	    break;
+	}
+      walk_stmts (wi, &BIND_EXPR_BODY (t));
+      break;
+
+    case RETURN_EXPR:
+      if (wi->want_return_expr)
+	{
+	  walk_subtrees = 1;
+	  wi->callback (tp, &walk_subtrees, wi);
+	  if (!walk_subtrees)
+	    break;
+	}
+      walk_stmts (wi, &TREE_OPERAND (t, 0));
+      break;
+
+    case MODIFY_EXPR:
+      /* A formal temporary lhs may use a COMPONENT_REF rhs.  */
+      wi->val_only = !is_gimple_formal_tmp_var (TREE_OPERAND (t, 0));
+      walk_tree (&TREE_OPERAND (t, 1), wi->callback, wi, NULL);
+
+      /* If the rhs is appropriate for a memory, we may use a
+	 COMPONENT_REF on the lhs.  */
+      wi->val_only = !is_gimple_mem_rhs (TREE_OPERAND (t, 1));
+      wi->is_lhs = true;
+      walk_tree (&TREE_OPERAND (t, 0), wi->callback, wi, NULL);
+
+      wi->val_only = true;
+      wi->is_lhs = false;
+      break;
+
+    case ASM_EXPR:
+      walk_asm_expr (wi, *tp);
+      break;
+
+    default:
+      wi->val_only = true;
+      walk_tree (tp, wi->callback, wi, NULL);
+      break;
+    }
+}
+
+/* Invoke CALLBACK on all statements of *STMT_P.  */
+
+static void
+walk_body (walk_tree_fn callback, struct nesting_info *info, tree *stmt_p)
+{
+  struct walk_stmt_info wi;
+
+  memset (&wi, 0, sizeof (wi));
+  wi.callback = callback;
+  wi.info = info;
+  wi.val_only = true;
+
+  walk_stmts (&wi, stmt_p);
+}
+
+/* Invoke CALLBACK on all statements of INFO->CONTEXT.  */
+
+static inline void
+walk_function (walk_tree_fn callback, struct nesting_info *info)
+{
+  walk_body (callback, info, &DECL_SAVED_TREE (info->context));
+}
+
+/* Similarly for ROOT and all functions nested underneath, depth first.  */
+    
+static void
+walk_all_functions (walk_tree_fn callback, struct nesting_info *root)
+{
+  do
+    {
+      if (root->inner)
+	walk_all_functions (callback, root->inner);
+      walk_function (callback, root);
+      root = root->next;
+    }
+  while (root);
+}
+
+/* We have to check for a fairly pathological case.  The operands of function
+   nested function are to be interpreted in the context of the enclosing
+   function.  So if any are variably-sized, they will get remapped when the
+   enclosing function is inlined.  But that remapping would also have to be
+   done in the types of the PARM_DECLs of the nested function, meaning the
+   argument types of that function will disagree with the arguments in the
+   calls to that function.  So we'd either have to make a copy of the nested
+   function corresponding to each time the enclosing function was inlined or
+   add a VIEW_CONVERT_EXPR to each such operand for each call to the nested
+   function.  The former is not practical.  The latter would still require
+   detecting this case to know when to add the conversions.  So, for now at
+   least, we don't inline such an enclosing function.
+
+   We have to do that check recursively, so here return indicating whether
+   FNDECL has such a nested function.  ORIG_FN is the function we were
+   trying to inline to use for checking whether any argument is variably
+   modified by anything in it.
+
+   It would be better to do this in tree-inline.c so that we could give
+   the appropriate warning for why a function can't be inlined, but that's
+   too late since the nesting structure has already been flattened and
+   adding a flag just to record this fact seems a waste of a flag.  */
+
+static bool
+check_for_nested_with_variably_modified (tree fndecl, tree orig_fndecl)
+{
+  struct cgraph_node *cgn = cgraph_node (fndecl);
+  tree arg;
+
+  for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested)
+    {
+      for (arg = DECL_ARGUMENTS (cgn->decl); arg; arg = TREE_CHAIN (arg))
+	if (variably_modified_type_p (TREE_TYPE (arg), 0), orig_fndecl)
+	  return true;
+
+      if (check_for_nested_with_variably_modified (cgn->decl, orig_fndecl))
+	return true;
+    }
+
+  return false;
+}
+
+/* Construct our local datastructure describing the function nesting
+   tree rooted by CGN.  */
+
+static struct nesting_info *
+create_nesting_tree (struct cgraph_node *cgn)
+{
+  struct nesting_info *info = GGC_CNEW (struct nesting_info);
+  info->field_map = htab_create_ggc (7, var_map_hash, var_map_eq, ggc_free);
+  info->var_map = htab_create_ggc (7, var_map_hash, var_map_eq, ggc_free);
+  info->suppress_expansion = BITMAP_GGC_ALLOC ();
+  info->context = cgn->decl;
+
+  for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested)
+    {
+      struct nesting_info *sub = create_nesting_tree (cgn);
+      sub->outer = info;
+      sub->next = info->inner;
+      info->inner = sub;
+    }
+
+  /* See discussion at check_for_nested_with_variably_modified for a
+     discussion of why this has to be here.  */
+  if (check_for_nested_with_variably_modified (info->context, info->context))
+    DECL_UNINLINABLE (info->context) = true;
+
+  return info;
+}
+
+/* Return an expression computing the static chain for TARGET_CONTEXT
+   from INFO->CONTEXT.  Insert any necessary computations before TSI.  */
+
+static tree
+get_static_chain (struct nesting_info *info, tree target_context,
+		  tree_stmt_iterator *tsi)
+{
+  struct nesting_info *i;
+  tree x;
+
+  if (info->context == target_context)
+    {
+      x = build_addr (info->frame_decl, target_context);
+    }
+  else
+    {
+      x = get_chain_decl (info);
+
+      for (i = info->outer; i->context != target_context; i = i->outer)
+	{
+	  tree field = get_chain_field (i);
+
+	  x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
+	  x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
+	  x = init_tmp_var (info, x, tsi);
+	}
+    }
+
+  return x;
+}
+
+/* Return an expression referencing FIELD from TARGET_CONTEXT's non-local
+   frame as seen from INFO->CONTEXT.  Insert any necessary computations
+   before TSI.  */
+
+static tree
+get_frame_field (struct nesting_info *info, tree target_context,
+		 tree field, tree_stmt_iterator *tsi)
+{
+  struct nesting_info *i;
+  tree x;
+
+  if (info->context == target_context)
+    {
+      /* Make sure frame_decl gets created.  */
+      (void) get_frame_type (info);
+      x = info->frame_decl;
+    }
+  else
+    {
+      x = get_chain_decl (info);
+
+      for (i = info->outer; i->context != target_context; i = i->outer)
+	{
+	  tree field = get_chain_field (i);
+
+	  x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
+	  x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
+	  x = init_tmp_var (info, x, tsi);
+	}
+
+      x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
+    }
+
+  x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
+  return x;
+}
+
+/* A subroutine of convert_nonlocal_reference.  Create a local variable
+   in the nested function with DECL_VALUE_EXPR set to reference the true
+   variable in the parent function.  This is used both for debug info 
+   and in OpenMP lowering.  */
+
+static tree
+get_nonlocal_debug_decl (struct nesting_info *info, tree decl)
+{
+  struct var_map_elt *elt, dummy;
+  tree target_context;
+  struct nesting_info *i;
+  tree x, field, new_decl;
+  void **slot;
+
+  dummy.old = decl;
+  slot = htab_find_slot (info->var_map, &dummy, INSERT);
+  elt = *slot;
+
+  if (elt)
+    return elt->new;
+
+  target_context = decl_function_context (decl);
+
+  /* A copy of the code in get_frame_field, but without the temporaries.  */
+  if (info->context == target_context)
+    {
+      /* Make sure frame_decl gets created.  */
+      (void) get_frame_type (info);
+      x = info->frame_decl;
+      i = info;
+    }
+  else
+    {
+      x = get_chain_decl (info);
+      for (i = info->outer; i->context != target_context; i = i->outer)
+	{
+	  field = get_chain_field (i);
+	  x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
+	  x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
+	}
+      x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
+    }
+
+  field = lookup_field_for_decl (i, decl, INSERT);
+  x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
+  if (use_pointer_in_frame (decl))
+    x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
+
+  /* ??? We should be remapping types as well, surely.  */
+  new_decl = build_decl (VAR_DECL, DECL_NAME (decl), TREE_TYPE (decl));
+  DECL_CONTEXT (new_decl) = info->context;
+  DECL_SOURCE_LOCATION (new_decl) = DECL_SOURCE_LOCATION (decl);
+  DECL_ARTIFICIAL (new_decl) = DECL_ARTIFICIAL (decl);
+  DECL_IGNORED_P (new_decl) = DECL_IGNORED_P (decl);
+  TREE_THIS_VOLATILE (new_decl) = TREE_THIS_VOLATILE (decl);
+  TREE_SIDE_EFFECTS (new_decl) = TREE_SIDE_EFFECTS (decl);
+  TREE_READONLY (new_decl) = TREE_READONLY (decl);
+  TREE_ADDRESSABLE (new_decl) = TREE_ADDRESSABLE (decl);
+  DECL_SEEN_IN_BIND_EXPR_P (new_decl) = 1;
+
+  SET_DECL_VALUE_EXPR (new_decl, x);
+  DECL_HAS_VALUE_EXPR_P (new_decl) = 1;
+
+  elt = ggc_alloc (sizeof (*elt));
+  elt->old = decl;
+  elt->new = new_decl;
+  *slot = elt;
+
+  TREE_CHAIN (new_decl) = info->debug_var_chain;
+  info->debug_var_chain = new_decl;
+
+  return new_decl;
+}
+
+/* Called via walk_function+walk_tree, rewrite all references to VAR
+   and PARM_DECLs that belong to outer functions.
+
+   The rewrite will involve some number of structure accesses back up
+   the static chain.  E.g. for a variable FOO up one nesting level it'll
+   be CHAIN->FOO.  For two levels it'll be CHAIN->__chain->FOO.  Further
+   indirections apply to decls for which use_pointer_in_frame is true.  */
+
+static bool convert_nonlocal_omp_clauses (tree *, struct walk_stmt_info *);
+
+static tree
+convert_nonlocal_reference (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
+  struct nesting_info *info = wi->info;
+  tree t = *tp;
+  tree save_local_var_chain;
+  bitmap save_suppress;
+
+  *walk_subtrees = 0;
+  switch (TREE_CODE (t))
+    {
+    case VAR_DECL:
+      /* Non-automatic variables are never processed.  */
+      if (TREE_STATIC (t) || DECL_EXTERNAL (t))
+	break;
+      /* FALLTHRU */
+
+    case PARM_DECL:
+      if (decl_function_context (t) != info->context)
+	{
+	  tree x;
+	  wi->changed = true;
+
+	  x = get_nonlocal_debug_decl (info, t);
+	  if (!bitmap_bit_p (info->suppress_expansion, DECL_UID (t)))
+	    {
+	      tree target_context = decl_function_context (t);
+	      struct nesting_info *i;
+	      for (i = info->outer; i->context != target_context; i = i->outer)
+		continue;
+	      x = lookup_field_for_decl (i, t, INSERT);
+	      x = get_frame_field (info, target_context, x, &wi->tsi);
+	      if (use_pointer_in_frame (t))
+		{
+		  x = init_tmp_var (info, x, &wi->tsi);
+		  x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
+		}
+	    }
+
+	  if (wi->val_only)
+	    {
+	      if (wi->is_lhs)
+		x = save_tmp_var (info, x, &wi->tsi);
+	      else
+		x = init_tmp_var (info, x, &wi->tsi);
+	    }
+
+	  *tp = x;
+	}
+      break;
+
+    case GOTO_EXPR:
+      /* Don't walk non-local gotos for now.  */
+      if (TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL)
+	{
+	  *walk_subtrees = 1;
+	  wi->val_only = true;
+	  wi->is_lhs = false;
+	}
+      break;
+
+    case LABEL_DECL:
+      /* We're taking the address of a label from a parent function, but
+	 this is not itself a non-local goto.  Mark the label such that it
+	 will not be deleted, much as we would with a label address in
+	 static storage.  */
+      if (decl_function_context (t) != info->context)
+        FORCED_LABEL (t) = 1;
+      break;
+
+    case ADDR_EXPR:
+      {
+	bool save_val_only = wi->val_only;
+
+	wi->val_only = false;
+	wi->is_lhs = false;
+	wi->changed = false;
+	walk_tree (&TREE_OPERAND (t, 0), convert_nonlocal_reference, wi, NULL);
+	wi->val_only = true;
+
+	if (wi->changed)
+	  {
+	    tree save_context;
+
+	    /* If we changed anything, then TREE_INVARIANT is be wrong,
+	       since we're no longer directly referencing a decl.  */
+	    save_context = current_function_decl;
+	    current_function_decl = info->context;
+	    recompute_tree_invariant_for_addr_expr (t);
+	    current_function_decl = save_context;
+
+	    /* If the callback converted the address argument in a context
+	       where we only accept variables (and min_invariant, presumably),
+	       then compute the address into a temporary.  */
+	    if (save_val_only)
+	      *tp = tsi_gimplify_val (wi->info, t, &wi->tsi);
+	  }
+      }
+      break;
+
+    case REALPART_EXPR:
+    case IMAGPART_EXPR:
+    case COMPONENT_REF:
+    case ARRAY_REF:
+    case ARRAY_RANGE_REF:
+    case BIT_FIELD_REF:
+      /* Go down this entire nest and just look at the final prefix and
+	 anything that describes the references.  Otherwise, we lose track
+	 of whether a NOP_EXPR or VIEW_CONVERT_EXPR needs a simple value.  */
+      wi->val_only = true;
+      wi->is_lhs = false;
+      for (; handled_component_p (t); tp = &TREE_OPERAND (t, 0), t = *tp)
+	{
+	  if (TREE_CODE (t) == COMPONENT_REF)
+	    walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi,
+		       NULL);
+	  else if (TREE_CODE (t) == ARRAY_REF
+		   || TREE_CODE (t) == ARRAY_RANGE_REF)
+	    {
+	      walk_tree (&TREE_OPERAND (t, 1), convert_nonlocal_reference, wi,
+			 NULL);
+	      walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi,
+			 NULL);
+	      walk_tree (&TREE_OPERAND (t, 3), convert_nonlocal_reference, wi,
+			 NULL);
+	    }
+	  else if (TREE_CODE (t) == BIT_FIELD_REF)
+	    {
+	      walk_tree (&TREE_OPERAND (t, 1), convert_nonlocal_reference, wi,
+			 NULL);
+	      walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi,
+			 NULL);
+	    }
+	}
+      wi->val_only = false;
+      walk_tree (tp, convert_nonlocal_reference, wi, NULL);
+      break;
+
+    case OMP_PARALLEL:
+      save_suppress = info->suppress_expansion;
+      if (convert_nonlocal_omp_clauses (&OMP_PARALLEL_CLAUSES (t), wi))
+	{
+	  tree c, decl;
+	  decl = get_chain_decl (info);
+	  c = build_omp_clause (OMP_CLAUSE_FIRSTPRIVATE);
+	  OMP_CLAUSE_DECL (c) = decl;
+	  OMP_CLAUSE_CHAIN (c) = OMP_PARALLEL_CLAUSES (t);
+	  OMP_PARALLEL_CLAUSES (t) = c;
+	}
+
+      save_local_var_chain = info->new_local_var_chain;
+      info->new_local_var_chain = NULL;
+
+      walk_body (convert_nonlocal_reference, info, &OMP_PARALLEL_BODY (t));
+
+      if (info->new_local_var_chain)
+	declare_vars (info->new_local_var_chain, OMP_PARALLEL_BODY (t), false);
+      info->new_local_var_chain = save_local_var_chain;
+      info->suppress_expansion = save_suppress;
+      break;
+
+    case OMP_FOR:
+    case OMP_SECTIONS:
+    case OMP_SINGLE:
+      save_suppress = info->suppress_expansion;
+      convert_nonlocal_omp_clauses (&OMP_CLAUSES (t), wi);
+      walk_body (convert_nonlocal_reference, info, &OMP_BODY (t));
+      info->suppress_expansion = save_suppress;
+      break;
+
+    case OMP_SECTION:
+    case OMP_MASTER:
+    case OMP_ORDERED:
+      walk_body (convert_nonlocal_reference, info, &OMP_BODY (t));
+      break;
+
+    default:
+      if (!IS_TYPE_OR_DECL_P (t))
+	{
+	  *walk_subtrees = 1;
+          wi->val_only = true;
+	  wi->is_lhs = false;
+	}
+      break;
+    }
+
+  return NULL_TREE;
+}
+
+static bool
+convert_nonlocal_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
+{
+  struct nesting_info *info = wi->info;
+  bool need_chain = false;
+  tree clause, decl;
+  int dummy;
+  bitmap new_suppress;
+
+  new_suppress = BITMAP_GGC_ALLOC ();
+  bitmap_copy (new_suppress, info->suppress_expansion);
+
+  for (clause = *pclauses; clause ; clause = OMP_CLAUSE_CHAIN (clause))
+    {
+      switch (OMP_CLAUSE_CODE (clause))
+	{
+	case OMP_CLAUSE_PRIVATE:
+	case OMP_CLAUSE_FIRSTPRIVATE:
+	case OMP_CLAUSE_LASTPRIVATE:
+	case OMP_CLAUSE_REDUCTION:
+	case OMP_CLAUSE_COPYPRIVATE:
+	case OMP_CLAUSE_SHARED:
+	  decl = OMP_CLAUSE_DECL (clause);
+	  if (decl_function_context (decl) != info->context)
+	    {
+	      bitmap_set_bit (new_suppress, DECL_UID (decl));
+	      OMP_CLAUSE_DECL (clause) = get_nonlocal_debug_decl (info, decl);
+	      need_chain = true;
+	    }
+	  break;
+
+	case OMP_CLAUSE_SCHEDULE:
+	  if (OMP_CLAUSE_SCHEDULE_CHUNK_EXPR (clause) == NULL)
+	    break;
+	  /* FALLTHRU */
+	case OMP_CLAUSE_IF:
+	case OMP_CLAUSE_NUM_THREADS:
+	  wi->val_only = true;
+	  wi->is_lhs = false;
+	  convert_nonlocal_reference (&OMP_CLAUSE_OPERAND (clause, 0), &dummy,
+	                              wi);
+	  break;
+
+	case OMP_CLAUSE_NOWAIT:
+	case OMP_CLAUSE_ORDERED:
+	case OMP_CLAUSE_DEFAULT:
+	case OMP_CLAUSE_COPYIN:
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  info->suppress_expansion = new_suppress;
+
+  return need_chain;
+}
+
+/* A subroutine of convert_local_reference.  Create a local variable
+   in the parent function with DECL_VALUE_EXPR set to reference the
+   field in FRAME.  This is used both for debug info and in OpenMP
+   lowering.  */
+
+static tree
+get_local_debug_decl (struct nesting_info *info, tree decl, tree field)
+{
+  struct var_map_elt *elt, dummy;
+  tree x, new_decl;
+  void **slot;
+
+  dummy.old = decl;
+  slot = htab_find_slot (info->var_map, &dummy, INSERT);
+  elt = *slot;
+
+  if (elt)
+    return elt->new;
+
+  /* Make sure frame_decl gets created.  */
+  (void) get_frame_type (info);
+  x = info->frame_decl;
+  x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
+
+  new_decl = build_decl (VAR_DECL, DECL_NAME (decl), TREE_TYPE (decl));
+  DECL_CONTEXT (new_decl) = info->context;
+  DECL_SOURCE_LOCATION (new_decl) = DECL_SOURCE_LOCATION (decl);
+  DECL_ARTIFICIAL (new_decl) = DECL_ARTIFICIAL (decl);
+  DECL_IGNORED_P (new_decl) = DECL_IGNORED_P (decl);
+  TREE_THIS_VOLATILE (new_decl) = TREE_THIS_VOLATILE (decl);
+  TREE_SIDE_EFFECTS (new_decl) = TREE_SIDE_EFFECTS (decl);
+  TREE_READONLY (new_decl) = TREE_READONLY (decl);
+  TREE_ADDRESSABLE (new_decl) = TREE_ADDRESSABLE (decl);
+  DECL_SEEN_IN_BIND_EXPR_P (new_decl) = 1;
+
+  SET_DECL_VALUE_EXPR (new_decl, x);
+  DECL_HAS_VALUE_EXPR_P (new_decl) = 1;
+
+  elt = ggc_alloc (sizeof (*elt));
+  elt->old = decl;
+  elt->new = new_decl;
+  *slot = elt;
+
+  TREE_CHAIN (new_decl) = info->debug_var_chain;
+  info->debug_var_chain = new_decl;
+
+  /* Do not emit debug info twice.  */
+  DECL_IGNORED_P (decl) = 1;
+
+  return new_decl;
+}
+
+/* Called via walk_function+walk_tree, rewrite all references to VAR
+   and PARM_DECLs that were referenced by inner nested functions.
+   The rewrite will be a structure reference to the local frame variable.  */
+
+static bool convert_local_omp_clauses (tree *, struct walk_stmt_info *);
+
+static tree
+convert_local_reference (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
+  struct nesting_info *info = wi->info;
+  tree t = *tp, field, x;
+  bool save_val_only;
+  tree save_local_var_chain;
+  bitmap save_suppress;
+
+  *walk_subtrees = 0;
+  switch (TREE_CODE (t))
+    {
+    case VAR_DECL:
+      /* Non-automatic variables are never processed.  */
+      if (TREE_STATIC (t) || DECL_EXTERNAL (t))
+	break;
+      /* FALLTHRU */
+
+    case PARM_DECL:
+      if (decl_function_context (t) == info->context)
+	{
+	  /* If we copied a pointer to the frame, then the original decl
+	     is used unchanged in the parent function.  */
+	  if (use_pointer_in_frame (t))
+	    break;
+
+	  /* No need to transform anything if no child references the
+	     variable.  */
+	  field = lookup_field_for_decl (info, t, NO_INSERT);
+	  if (!field)
+	    break;
+	  wi->changed = true;
+
+	  x = get_local_debug_decl (info, t, field);
+	  if (!bitmap_bit_p (info->suppress_expansion, DECL_UID (t)))
+	    x = get_frame_field (info, info->context, field, &wi->tsi);
+
+	  if (wi->val_only)
+	    {
+	      if (wi->is_lhs)
+		x = save_tmp_var (info, x, &wi->tsi);
+	      else
+		x = init_tmp_var (info, x, &wi->tsi);
+	    }
+
+	  *tp = x;
+	}
+      break;
+
+    case ADDR_EXPR:
+      save_val_only = wi->val_only;
+      wi->val_only = false;
+      wi->is_lhs = false;
+      wi->changed = false;
+      walk_tree (&TREE_OPERAND (t, 0), convert_local_reference, wi, NULL);
+      wi->val_only = save_val_only;
+
+      /* If we converted anything ... */
+      if (wi->changed)
+	{
+	  tree save_context;
+
+	  /* Then the frame decl is now addressable.  */
+	  TREE_ADDRESSABLE (info->frame_decl) = 1;
+	    
+	  save_context = current_function_decl;
+	  current_function_decl = info->context;
+	  recompute_tree_invariant_for_addr_expr (t);
+	  current_function_decl = save_context;
+
+	  /* If we are in a context where we only accept values, then
+	     compute the address into a temporary.  */
+	  if (save_val_only)
+	    *tp = tsi_gimplify_val (wi->info, t, &wi->tsi);
+	}
+      break;
+
+    case REALPART_EXPR:
+    case IMAGPART_EXPR:
+    case COMPONENT_REF:
+    case ARRAY_REF:
+    case ARRAY_RANGE_REF:
+    case BIT_FIELD_REF:
+      /* Go down this entire nest and just look at the final prefix and
+	 anything that describes the references.  Otherwise, we lose track
+	 of whether a NOP_EXPR or VIEW_CONVERT_EXPR needs a simple value.  */
+      save_val_only = wi->val_only;
+      wi->val_only = true;
+      wi->is_lhs = false;
+      for (; handled_component_p (t); tp = &TREE_OPERAND (t, 0), t = *tp)
+	{
+	  if (TREE_CODE (t) == COMPONENT_REF)
+	    walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi,
+		       NULL);
+	  else if (TREE_CODE (t) == ARRAY_REF
+		   || TREE_CODE (t) == ARRAY_RANGE_REF)
+	    {
+	      walk_tree (&TREE_OPERAND (t, 1), convert_local_reference, wi,
+			 NULL);
+	      walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi,
+			 NULL);
+	      walk_tree (&TREE_OPERAND (t, 3), convert_local_reference, wi,
+			 NULL);
+	    }
+	  else if (TREE_CODE (t) == BIT_FIELD_REF)
+	    {
+	      walk_tree (&TREE_OPERAND (t, 1), convert_local_reference, wi,
+			 NULL);
+	      walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi,
+			 NULL);
+	    }
+	}
+      wi->val_only = false;
+      walk_tree (tp, convert_local_reference, wi, NULL);
+      wi->val_only = save_val_only;
+      break;
+
+    case OMP_PARALLEL:
+      save_suppress = info->suppress_expansion;
+      if (convert_local_omp_clauses (&OMP_PARALLEL_CLAUSES (t), wi))
+	{
+	  tree c;
+	  (void) get_frame_type (info);
+	  c = build_omp_clause (OMP_CLAUSE_SHARED);
+	  OMP_CLAUSE_DECL (c) = info->frame_decl;
+	  OMP_CLAUSE_CHAIN (c) = OMP_PARALLEL_CLAUSES (t);
+	  OMP_PARALLEL_CLAUSES (t) = c;
+	}
+
+      save_local_var_chain = info->new_local_var_chain;
+      info->new_local_var_chain = NULL;
+
+      walk_body (convert_local_reference, info, &OMP_PARALLEL_BODY (t));
+
+      if (info->new_local_var_chain)
+	declare_vars (info->new_local_var_chain, OMP_PARALLEL_BODY (t), false);
+      info->new_local_var_chain = save_local_var_chain;
+      info->suppress_expansion = save_suppress;
+      break;
+
+    case OMP_FOR:
+    case OMP_SECTIONS:
+    case OMP_SINGLE:
+      save_suppress = info->suppress_expansion;
+      convert_local_omp_clauses (&OMP_CLAUSES (t), wi);
+      walk_body (convert_local_reference, info, &OMP_BODY (t));
+      info->suppress_expansion = save_suppress;
+      break;
+
+    case OMP_SECTION:
+    case OMP_MASTER:
+    case OMP_ORDERED:
+      walk_body (convert_local_reference, info, &OMP_BODY (t));
+      break;
+
+    default:
+      if (!IS_TYPE_OR_DECL_P (t))
+	{
+	  *walk_subtrees = 1;
+	  wi->val_only = true;
+	  wi->is_lhs = false;
+	}
+      break;
+    }
+
+  return NULL_TREE;
+}
+
+static bool
+convert_local_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
+{
+  struct nesting_info *info = wi->info;
+  bool need_frame = false;
+  tree clause, decl;
+  int dummy;
+  bitmap new_suppress;
+
+  new_suppress = BITMAP_GGC_ALLOC ();
+  bitmap_copy (new_suppress, info->suppress_expansion);
+
+  for (clause = *pclauses; clause ; clause = OMP_CLAUSE_CHAIN (clause))
+    {
+      switch (OMP_CLAUSE_CODE (clause))
+	{
+	case OMP_CLAUSE_PRIVATE:
+	case OMP_CLAUSE_FIRSTPRIVATE:
+	case OMP_CLAUSE_LASTPRIVATE:
+	case OMP_CLAUSE_REDUCTION:
+	case OMP_CLAUSE_COPYPRIVATE:
+	case OMP_CLAUSE_SHARED:
+	  decl = OMP_CLAUSE_DECL (clause);
+	  if (decl_function_context (decl) == info->context
+	      && !use_pointer_in_frame (decl))
+	    {
+	      tree field = lookup_field_for_decl (info, decl, NO_INSERT);
+	      if (field)
+		{
+		  bitmap_set_bit (new_suppress, DECL_UID (decl));
+		  OMP_CLAUSE_DECL (clause)
+		    = get_local_debug_decl (info, decl, field);
+		  need_frame = true;
+		}
+	    }
+	  break;
+
+	case OMP_CLAUSE_SCHEDULE:
+	  if (OMP_CLAUSE_SCHEDULE_CHUNK_EXPR (clause) == NULL)
+	    break;
+	  /* FALLTHRU */
+	case OMP_CLAUSE_IF:
+	case OMP_CLAUSE_NUM_THREADS:
+	  wi->val_only = true;
+	  wi->is_lhs = false;
+	  convert_local_reference (&OMP_CLAUSE_OPERAND (clause, 0), &dummy, wi);
+	  break;
+
+	case OMP_CLAUSE_NOWAIT:
+	case OMP_CLAUSE_ORDERED:
+	case OMP_CLAUSE_DEFAULT:
+	case OMP_CLAUSE_COPYIN:
+	  break;
+
+	default:
+	  gcc_unreachable ();
+	}
+    }
+
+  info->suppress_expansion = new_suppress;
+
+  return need_frame;
+}
+
+/* Called via walk_function+walk_tree, rewrite all GOTO_EXPRs that 
+   reference labels from outer functions.  The rewrite will be a 
+   call to __builtin_nonlocal_goto.  */
+
+static tree
+convert_nl_goto_reference (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
+  struct nesting_info *info = wi->info, *i;
+  tree t = *tp, label, new_label, target_context, x, arg, field;
+  struct var_map_elt *elt, dummy;
+  void **slot;
+
+  *walk_subtrees = 0;
+  if (TREE_CODE (t) != GOTO_EXPR)
+    return NULL_TREE;
+  label = GOTO_DESTINATION (t);
+  if (TREE_CODE (label) != LABEL_DECL)
+    return NULL_TREE;
+  target_context = decl_function_context (label);
+  if (target_context == info->context)
+    return NULL_TREE;
+
+  for (i = info->outer; target_context != i->context; i = i->outer)
+    continue;
+
+  /* The original user label may also be use for a normal goto, therefore
+     we must create a new label that will actually receive the abnormal
+     control transfer.  This new label will be marked LABEL_NONLOCAL; this
+     mark will trigger proper behavior in the cfg, as well as cause the
+     (hairy target-specific) non-local goto receiver code to be generated
+     when we expand rtl.  Enter this association into var_map so that we
+     can insert the new label into the IL during a second pass.  */
+  dummy.old = label;
+  slot = htab_find_slot (i->var_map, &dummy, INSERT);
+  elt = (struct var_map_elt *) *slot;
+  if (elt == NULL)
+    {
+      new_label = create_artificial_label ();
+      DECL_NONLOCAL (new_label) = 1;
+
+      elt = GGC_NEW (struct var_map_elt); 
+      elt->old = label;
+      elt->new = new_label;
+      *slot = elt;
+    }
+  else
+    new_label = elt->new;
+  
+  /* Build: __builtin_nl_goto(new_label, &chain->nl_goto_field).  */
+  field = get_nl_goto_field (i);
+  x = get_frame_field (info, target_context, field, &wi->tsi);
+  x = build_addr (x, target_context);
+  x = tsi_gimplify_val (info, x, &wi->tsi);
+  arg = tree_cons (NULL, x, NULL);
+  x = build_addr (new_label, target_context);
+  arg = tree_cons (NULL, x, arg);
+  x = implicit_built_in_decls[BUILT_IN_NONLOCAL_GOTO];
+  x = build_function_call_expr (x, arg);
+
+  SET_EXPR_LOCUS (x, EXPR_LOCUS (tsi_stmt (wi->tsi)));
+  *tsi_stmt_ptr (wi->tsi) = x;
+
+  return NULL_TREE;
+}
+
+/* Called via walk_function+walk_tree, rewrite all LABEL_EXPRs that 
+   are referenced via nonlocal goto from a nested function.  The rewrite
+   will involve installing a newly generated DECL_NONLOCAL label, and
+   (potentially) a branch around the rtl gunk that is assumed to be 
+   attached to such a label.  */
+
+static tree
+convert_nl_goto_receiver (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
+  struct nesting_info *info = wi->info;
+  tree t = *tp, label, new_label, x;
+  struct var_map_elt *elt, dummy;
+  tree_stmt_iterator tmp_tsi;
+
+  *walk_subtrees = 0;
+  if (TREE_CODE (t) != LABEL_EXPR)
+    return NULL_TREE;
+  label = LABEL_EXPR_LABEL (t);
+
+  dummy.old = label;
+  elt = (struct var_map_elt *) htab_find (info->var_map, &dummy);
+  if (!elt)
+    return NULL_TREE;
+  new_label = elt->new;
+
+  /* If there's any possibility that the previous statement falls through,
+     then we must branch around the new non-local label.  */
+  tmp_tsi = wi->tsi;
+  tsi_prev (&tmp_tsi);
+  if (tsi_end_p (tmp_tsi) || block_may_fallthru (tsi_stmt (tmp_tsi)))
+    {
+      x = build1 (GOTO_EXPR, void_type_node, label);
+      tsi_link_before (&wi->tsi, x, TSI_SAME_STMT);
+    }
+  x = build1 (LABEL_EXPR, void_type_node, new_label);
+  tsi_link_before (&wi->tsi, x, TSI_SAME_STMT);
+
+  return NULL_TREE;
+}
+
+/* Called via walk_function+walk_tree, rewrite all references to addresses
+   of nested functions that require the use of trampolines.  The rewrite
+   will involve a reference a trampoline generated for the occasion.  */
+
+static tree
+convert_tramp_reference (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
+  struct nesting_info *info = wi->info, *i;
+  tree t = *tp, decl, target_context, x, arg;
+
+  *walk_subtrees = 0;
+  switch (TREE_CODE (t))
+    {
+    case ADDR_EXPR:
+      /* Build
+	   T.1 = &CHAIN->tramp;
+	   T.2 = __builtin_adjust_trampoline (T.1);
+	   T.3 = (func_type)T.2;
+      */
+
+      decl = TREE_OPERAND (t, 0);
+      if (TREE_CODE (decl) != FUNCTION_DECL)
+	break;
+
+      /* Only need to process nested functions.  */
+      target_context = decl_function_context (decl);
+      if (!target_context)
+	break;
+
+      /* If the nested function doesn't use a static chain, then
+	 it doesn't need a trampoline.  */
+      if (DECL_NO_STATIC_CHAIN (decl))
+	break;
+
+      /* Lookup the immediate parent of the callee, as that's where
+	 we need to insert the trampoline.  */
+      for (i = info; i->context != target_context; i = i->outer)
+	continue;
+      x = lookup_tramp_for_decl (i, decl, INSERT);
+
+      /* Compute the address of the field holding the trampoline.  */
+      x = get_frame_field (info, target_context, x, &wi->tsi);
+      x = build_addr (x, target_context);
+      x = tsi_gimplify_val (info, x, &wi->tsi);
+      arg = tree_cons (NULL, x, NULL);
+
+      /* Do machine-specific ugliness.  Normally this will involve
+	 computing extra alignment, but it can really be anything.  */
+      x = implicit_built_in_decls[BUILT_IN_ADJUST_TRAMPOLINE];
+      x = build_function_call_expr (x, arg);
+      x = init_tmp_var (info, x, &wi->tsi);
+
+      /* Cast back to the proper function type.  */
+      x = build1 (NOP_EXPR, TREE_TYPE (t), x);
+      x = init_tmp_var (info, x, &wi->tsi);
+
+      *tp = x;
+      break;
+
+    case CALL_EXPR:
+      /* Only walk call arguments, lest we generate trampolines for
+	 direct calls.  */
+      walk_tree (&TREE_OPERAND (t, 1), convert_tramp_reference, wi, NULL);
+      break;
+
+    default:
+      if (!IS_TYPE_OR_DECL_P (t))
+	*walk_subtrees = 1;
+      break;
+    }
+
+  return NULL_TREE;
+}
+
+/* Called via walk_function+walk_tree, rewrite all CALL_EXPRs that 
+   reference nested functions to make sure that the static chain is
+   set up properly for the call.  */
+
+static tree
+convert_call_expr (tree *tp, int *walk_subtrees, void *data)
+{
+  struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
+  struct nesting_info *info = wi->info;
+  tree t = *tp, decl, target_context;
+  char save_static_chain_added;
+  int i;
+
+  *walk_subtrees = 0;
+  switch (TREE_CODE (t))
+    {
+    case CALL_EXPR:
+      decl = get_callee_fndecl (t);
+      if (!decl)
+	break;
+      target_context = decl_function_context (decl);
+      if (target_context && !DECL_NO_STATIC_CHAIN (decl))
+	{
+	  TREE_OPERAND (t, 2)
+	    = get_static_chain (info, target_context, &wi->tsi);
+	  info->static_chain_added
+	    |= (1 << (info->context != target_context));
+	}
+      break;
+
+    case RETURN_EXPR:
+    case MODIFY_EXPR:
+    case WITH_SIZE_EXPR:
+      /* Only return modify and with_size_expr may contain calls.  */
+      *walk_subtrees = 1;
+      break;
+
+    case OMP_PARALLEL:
+      save_static_chain_added = info->static_chain_added;
+      info->static_chain_added = 0;
+      walk_body (convert_call_expr, info, &OMP_PARALLEL_BODY (t));
+      for (i = 0; i < 2; i++)
+	{
+	  tree c, decl;
+	  if ((info->static_chain_added & (1 << i)) == 0)
+	    continue;
+	  decl = i ? get_chain_decl (info) : info->frame_decl;
+	  /* Don't add CHAIN.* or FRAME.* twice.  */
+	  for (c = OMP_PARALLEL_CLAUSES (t); c; c = OMP_CLAUSE_CHAIN (c))
+	    if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
+		 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_SHARED)
+		&& OMP_CLAUSE_DECL (c) == decl)
+	      break;
+	  if (c == NULL)
+	    {
+	      c = build_omp_clause (OMP_CLAUSE_FIRSTPRIVATE);
+	      OMP_CLAUSE_DECL (c) = decl;
+	      OMP_CLAUSE_CHAIN (c) = OMP_PARALLEL_CLAUSES (t);
+	      OMP_PARALLEL_CLAUSES (t) = c;
+	    }
+	}
+      info->static_chain_added |= save_static_chain_added;
+      break;
+
+    case OMP_FOR:
+    case OMP_SECTIONS:
+    case OMP_SECTION:
+    case OMP_SINGLE:
+    case OMP_MASTER:
+    case OMP_ORDERED:
+    case OMP_CRITICAL:
+      walk_body (convert_call_expr, info, &OMP_BODY (t));
+      break;
+
+    default:
+      break;
+    }
+
+  return NULL_TREE;
+}
+
+/* Walk the nesting tree starting with ROOT, depth first.  Convert all
+   trampolines and call expressions.  On the way back up, determine if
+   a nested function actually uses its static chain; if not, remember that.  */
+
+static void
+convert_all_function_calls (struct nesting_info *root)
+{
+  do
+    {
+      if (root->inner)
+	convert_all_function_calls (root->inner);
+
+      walk_function (convert_tramp_reference, root);
+      walk_function (convert_call_expr, root);
+
+      /* If the function does not use a static chain, then remember that.  */
+      if (root->outer && !root->chain_decl && !root->chain_field)
+	DECL_NO_STATIC_CHAIN (root->context) = 1;
+      else
+	gcc_assert (!DECL_NO_STATIC_CHAIN (root->context));
+
+      root = root->next;
+    }
+  while (root);
+}
+
+/* Do "everything else" to clean up or complete state collected by the
+   various walking passes -- lay out the types and decls, generate code
+   to initialize the frame decl, store critical expressions in the
+   struct function for rtl to find.  */
+
+static void
+finalize_nesting_tree_1 (struct nesting_info *root)
+{
+  tree stmt_list = NULL;
+  tree context = root->context;
+  struct function *sf;
+
+  /* If we created a non-local frame type or decl, we need to lay them
+     out at this time.  */
+  if (root->frame_type)
+    {
+      /* In some cases the frame type will trigger the -Wpadded warning.
+	 This is not helpful; suppress it. */
+      int save_warn_padded = warn_padded;
+      warn_padded = 0;
+      layout_type (root->frame_type);
+      warn_padded = save_warn_padded;
+      layout_decl (root->frame_decl, 0);
+    }
+
+  /* If any parameters were referenced non-locally, then we need to 
+     insert a copy.  Likewise, if any variables were referenced by
+     pointer, we need to initialize the address.  */
+  if (root->any_parm_remapped)
+    {
+      tree p;
+      for (p = DECL_ARGUMENTS (context); p ; p = TREE_CHAIN (p))
+	{
+	  tree field, x, y;
+
+	  field = lookup_field_for_decl (root, p, NO_INSERT);
+	  if (!field)
+	    continue;
+
+	  if (use_pointer_in_frame (p))
+	    x = build_addr (p, context);
+	  else
+	    x = p;
+
+	  y = build3 (COMPONENT_REF, TREE_TYPE (field),
+		      root->frame_decl, field, NULL_TREE);
+	  x = build2 (MODIFY_EXPR, TREE_TYPE (field), y, x);
+	  append_to_statement_list (x, &stmt_list);
+	}
+    }
+
+  /* If a chain_field was created, then it needs to be initialized
+     from chain_decl.  */
+  if (root->chain_field)
+    {
+      tree x = build3 (COMPONENT_REF, TREE_TYPE (root->chain_field),
+		       root->frame_decl, root->chain_field, NULL_TREE);
+      x = build2 (MODIFY_EXPR, TREE_TYPE (x), x, get_chain_decl (root));
+      append_to_statement_list (x, &stmt_list);
+    }
+
+  /* If trampolines were created, then we need to initialize them.  */
+  if (root->any_tramp_created)
+    {
+      struct nesting_info *i;
+      for (i = root->inner; i ; i = i->next)
+	{
+	  tree arg, x, field;
+
+	  field = lookup_tramp_for_decl (root, i->context, NO_INSERT);
+	  if (!field)
+	    continue;
+
+	  if (DECL_NO_STATIC_CHAIN (i->context))
+	    x = null_pointer_node;
+	  else
+	    x = build_addr (root->frame_decl, context);
+	  arg = tree_cons (NULL, x, NULL);
+
+	  x = build_addr (i->context, context);
+	  arg = tree_cons (NULL, x, arg);
+
+	  x = build3 (COMPONENT_REF, TREE_TYPE (field),
+		      root->frame_decl, field, NULL_TREE);
+	  x = build_addr (x, context);
+	  arg = tree_cons (NULL, x, arg);
+
+	  x = implicit_built_in_decls[BUILT_IN_INIT_TRAMPOLINE];
+	  x = build_function_call_expr (x, arg);
+
+	  append_to_statement_list (x, &stmt_list);
+	}
+    }
+
+  /* If we created initialization statements, insert them.  */
+  if (stmt_list)
+    {
+      annotate_all_with_locus (&stmt_list,
+			       DECL_SOURCE_LOCATION (context));
+      append_to_statement_list (BIND_EXPR_BODY (DECL_SAVED_TREE (context)),
+				&stmt_list);
+      BIND_EXPR_BODY (DECL_SAVED_TREE (context)) = stmt_list;
+    }
+
+  /* If a chain_decl was created, then it needs to be registered with
+     struct function so that it gets initialized from the static chain
+     register at the beginning of the function.  */
+  sf = DECL_STRUCT_FUNCTION (root->context);
+  sf->static_chain_decl = root->chain_decl;
+
+  /* Similarly for the non-local goto save area.  */
+  if (root->nl_goto_field)
+    {
+      sf->nonlocal_goto_save_area
+	= get_frame_field (root, context, root->nl_goto_field, NULL);
+      sf->has_nonlocal_label = 1;
+    }
+
+  /* Make sure all new local variables get inserted into the
+     proper BIND_EXPR.  */
+  if (root->new_local_var_chain)
+    declare_vars (root->new_local_var_chain, DECL_SAVED_TREE (root->context),
+		  false);
+  if (root->debug_var_chain)
+    declare_vars (root->debug_var_chain, DECL_SAVED_TREE (root->context),
+		  true);
+
+  /* Dump the translated tree function.  */
+  dump_function (TDI_nested, root->context);
+}
+
+static void
+finalize_nesting_tree (struct nesting_info *root)
+{
+  do
+    {
+      if (root->inner)
+	finalize_nesting_tree (root->inner);
+      finalize_nesting_tree_1 (root);
+      root = root->next;
+    }
+  while (root);
+}
+
+/* Unnest the nodes and pass them to cgraph.  */
+
+static void
+unnest_nesting_tree_1 (struct nesting_info *root)
+{
+  struct cgraph_node *node = cgraph_node (root->context);
+
+  /* For nested functions update the cgraph to reflect unnesting.
+     We also delay finalizing of these functions up to this point.  */
+  if (node->origin)
+    {
+       cgraph_unnest_node (cgraph_node (root->context));
+       cgraph_finalize_function (root->context, true);
+    }
+}
+
+static void
+unnest_nesting_tree (struct nesting_info *root)
+{
+  do
+    {
+      if (root->inner)
+	unnest_nesting_tree (root->inner);
+      unnest_nesting_tree_1 (root);
+      root = root->next;
+    }
+  while (root);
+}
+
+/* Free the data structures allocated during this pass.  */
+
+static void
+free_nesting_tree (struct nesting_info *root)
+{
+  struct nesting_info *next;
+  do
+    {
+      if (root->inner)
+	free_nesting_tree (root->inner);
+      htab_delete (root->var_map);
+      next = root->next;
+      ggc_free (root);
+      root = next;
+    }
+  while (root);
+}
+
+static GTY(()) struct nesting_info *root;
+
+/* Main entry point for this pass.  Process FNDECL and all of its nested
+   subroutines and turn them into something less tightly bound.  */
+
+void
+lower_nested_functions (tree fndecl)
+{
+  struct cgraph_node *cgn;
+
+  /* If there are no nested functions, there's nothing to do.  */
+  cgn = cgraph_node (fndecl);
+  if (!cgn->nested)
+    return;
+
+  root = create_nesting_tree (cgn);
+  walk_all_functions (convert_nonlocal_reference, root);
+  walk_all_functions (convert_local_reference, root);
+  walk_all_functions (convert_nl_goto_reference, root);
+  walk_all_functions (convert_nl_goto_receiver, root);
+  convert_all_function_calls (root);
+  finalize_nesting_tree (root);
+  unnest_nesting_tree (root);
+  free_nesting_tree (root);
+  root = NULL;
+}
+
+#include "gt-tree-nested.h"