gcc/tree-nested.c

   1 /* Nested function decomposition for trees.
   2    Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
   3
   4    This file is part of GCC.
   5
   6    GCC is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    GCC is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GCC; see the file COPYING.  If not, write to
  18    the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  19    Boston, MA 02110-1301, USA.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "tm.h"
  25 #include "tree.h"
  26 #include "rtl.h"
  27 #include "tm_p.h"
  28 #include "function.h"
  29 #include "tree-dump.h"
  30 #include "tree-inline.h"
  31 #include "tree-gimple.h"
  32 #include "tree-iterator.h"
  33 #include "tree-flow.h"
  34 #include "cgraph.h"
  35 #include "expr.h"
  36 #include "langhooks.h"
  37 #include "ggc.h"
  38
  39
  40 /* The object of this pass is to lower the representation of a set of nested
  41    functions in order to expose all of the gory details of the various
  42    nonlocal references.  We want to do this sooner rather than later, in
  43    order to give us more freedom in emitting all of the functions in question.
  44
  45    Back in olden times, when gcc was young, we developed an insanely
  46    complicated scheme whereby variables which were referenced nonlocally
  47    were forced to live in the stack of the declaring function, and then
  48    the nested functions magically discovered where these variables were
  49    placed.  In order for this scheme to function properly, it required
  50    that the outer function be partially expanded, then we switch to
  51    compiling the inner function, and once done with those we switch back
  52    to compiling the outer function.  Such delicate ordering requirements
  53    makes it difficult to do whole translation unit optimizations
  54    involving such functions.
  55
  56    The implementation here is much more direct.  Everything that can be
  57    referenced by an inner function is a member of an explicitly created
  58    structure herein called the "nonlocal frame struct".  The incoming
  59    static chain for a nested function is a pointer to this struct in
  60    the parent.  In this way, we settle on known offsets from a known
  61    base, and so are decoupled from the logic that places objects in the
  62    function's stack frame.  More importantly, we don't have to wait for
  63    that to happen -- since the compilation of the inner function is no
  64    longer tied to a real stack frame, the nonlocal frame struct can be
  65    allocated anywhere.  Which means that the outer function is now
  66    inlinable.
  67
  68    Theory of operation here is very simple.  Iterate over all the
  69    statements in all the functions (depth first) several times,
  70    allocating structures and fields on demand.  In general we want to
  71    examine inner functions first, so that we can avoid making changes
  72    to outer functions which are unnecessary.
  73
  74    The order of the passes matters a bit, in that later passes will be
  75    skipped if it is discovered that the functions don't actually interact
  76    at all.  That is, they're nested in the lexical sense but could have
  77    been written as independent functions without change.  */
  78
  79
  80 struct var_map_elt GTY(())
  81 {
  82   tree old;
  83   tree new;
  84 };
  85
  86 struct nesting_info GTY ((chain_next ("%h.next")))
  87 {
  88   struct nesting_info *outer;
  89   struct nesting_info *inner;
  90   struct nesting_info *next;
  91
  92   htab_t GTY ((param_is (struct var_map_elt))) field_map;
  93   htab_t GTY ((param_is (struct var_map_elt))) var_map;
  94   bitmap suppress_expansion;
  95
  96   tree context;
  97   tree new_local_var_chain;
  98   tree debug_var_chain;
  99   tree frame_type;
 100   tree frame_decl;
 101   tree chain_field;
 102   tree chain_decl;
 103   tree nl_goto_field;
 104
 105   bool any_parm_remapped;
 106   bool any_tramp_created;
 107   char static_chain_added;
 108 };
 109
 110
 111 /* Hashing and equality functions for nesting_info->var_map.  */
 112
 113 static hashval_t
 114 var_map_hash (const void *x)
 115 {
 116   const struct var_map_elt *a = (const struct var_map_elt *) x;
 117   return htab_hash_pointer (a->old);
 118 }
 119
 120 static int
 121 var_map_eq (const void *x, const void *y)
 122 {
 123   const struct var_map_elt *a = (const struct var_map_elt *) x;
 124   const struct var_map_elt *b = (const struct var_map_elt *) y;
 125   return a->old == b->old;
 126 }
 127
 128 /* We're working in so many different function contexts simultaneously,
 129    that create_tmp_var is dangerous.  Prevent mishap.  */
 130 #define create_tmp_var cant_use_create_tmp_var_here_dummy
 131
 132 /* Like create_tmp_var, except record the variable for registration at
 133    the given nesting level.  */
 134
 135 static tree
 136 create_tmp_var_for (struct nesting_info *info, tree type, const char *prefix)
 137 {
 138   tree tmp_var;
 139
 140   /* If the type is of variable size or a type which must be created by the
 141      frontend, something is wrong.  Note that we explicitly allow
 142      incomplete types here, since we create them ourselves here.  */
 143   gcc_assert (!TREE_ADDRESSABLE (type));
 144   gcc_assert (!TYPE_SIZE_UNIT (type)
 145               || TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST);
 146
 147   tmp_var = create_tmp_var_raw (type, prefix);
 148   DECL_CONTEXT (tmp_var) = info->context;
 149   TREE_CHAIN (tmp_var) = info->new_local_var_chain;
 150   DECL_SEEN_IN_BIND_EXPR_P (tmp_var) = 1;
 151   if (TREE_CODE (type) == COMPLEX_TYPE
 152       || TREE_CODE (type) == VECTOR_TYPE)
 153     DECL_GIMPLE_REG_P (tmp_var) = 1;
 154
 155   info->new_local_var_chain = tmp_var;
 156
 157   return tmp_var;
 158 }
 159
 160 /* Take the address of EXP to be used within function CONTEXT.
 161    Mark it for addressability as necessary.  */
 162
 163 tree
 164 build_addr (tree exp, tree context)
 165 {
 166   tree base = exp;
 167   tree save_context;
 168   tree retval;
 169
 170   while (handled_component_p (base))
 171     base = TREE_OPERAND (base, 0);
 172
 173   if (DECL_P (base))
 174     TREE_ADDRESSABLE (base) = 1;
 175
 176   /* Building the ADDR_EXPR will compute a set of properties for
 177      that ADDR_EXPR.  Those properties are unfortunately context
 178      specific.  ie, they are dependent on CURRENT_FUNCTION_DECL.
 179
 180      Temporarily set CURRENT_FUNCTION_DECL to the desired context,
 181      build the ADDR_EXPR, then restore CURRENT_FUNCTION_DECL.  That
 182      way the properties are for the ADDR_EXPR are computed properly.  */
 183   save_context = current_function_decl;
 184   current_function_decl = context;
 185   retval = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp);
 186   current_function_decl = save_context;;
 187   return retval;
 188 }
 189
 190 /* Insert FIELD into TYPE, sorted by alignment requirements.  */
 191
 192 void
 193 insert_field_into_struct (tree type, tree field)
 194 {
 195   tree *p;
 196
 197   DECL_CONTEXT (field) = type;
 198
 199   for (p = &TYPE_FIELDS (type); *p ; p = &TREE_CHAIN (*p))
 200     if (DECL_ALIGN (field) >= DECL_ALIGN (*p))
 201       break;
 202
 203   TREE_CHAIN (field) = *p;
 204   *p = field;
 205 }
 206
 207 /* Build or return the RECORD_TYPE that describes the frame state that is
 208    shared between INFO->CONTEXT and its nested functions.  This record will
 209    not be complete until finalize_nesting_tree; up until that point we'll
 210    be adding fields as necessary.
 211
 212    We also build the DECL that represents this frame in the function.  */
 213
 214 static tree
 215 get_frame_type (struct nesting_info *info)
 216 {
 217   tree type = info->frame_type;
 218   if (!type)
 219     {
 220       char *name;
 221
 222       type = make_node (RECORD_TYPE);
 223
 224       name = concat ("FRAME.",
 225                      IDENTIFIER_POINTER (DECL_NAME (info->context)),
 226                      NULL);
 227       TYPE_NAME (type) = get_identifier (name);
 228       free (name);
 229
 230       info->frame_type = type;
 231       info->frame_decl = create_tmp_var_for (info, type, "FRAME");
 232
 233       /* ??? Always make it addressable for now, since it is meant to
 234          be pointed to by the static chain pointer.  This pessimizes
 235          when it turns out that no static chains are needed because
 236          the nested functions referencing non-local variables are not
 237          reachable, but the true pessimization is to create the non-
 238          local frame structure in the first place.  */
 239       TREE_ADDRESSABLE (info->frame_decl) = 1;
 240     }
 241   return type;
 242 }
 243
 244 /* Return true if DECL should be referenced by pointer in the non-local
 245    frame structure.  */
 246
 247 static bool
 248 use_pointer_in_frame (tree decl)
 249 {
 250   if (TREE_CODE (decl) == PARM_DECL)
 251     {
 252       /* It's illegal to copy TREE_ADDRESSABLE, impossible to copy variable
 253          sized decls, and inefficient to copy large aggregates.  Don't bother
 254          moving anything but scalar variables.  */
 255       return AGGREGATE_TYPE_P (TREE_TYPE (decl));
 256     }
 257   else
 258     {
 259       /* Variable sized types make things "interesting" in the frame.  */
 260       return DECL_SIZE (decl) == NULL || !TREE_CONSTANT (DECL_SIZE (decl));
 261     }
 262 }
 263
 264 /* Given DECL, a non-locally accessed variable, find or create a field
 265    in the non-local frame structure for the given nesting context.  */
 266
 267 static tree
 268 lookup_field_for_decl (struct nesting_info *info, tree decl,
 269                        enum insert_option insert)
 270 {
 271   struct var_map_elt *elt, dummy;
 272   void **slot;
 273   tree field;
 274
 275   dummy.old = decl;
 276   slot = htab_find_slot (info->field_map, &dummy, insert);
 277   if (!slot)
 278     {
 279       gcc_assert (insert != INSERT);
 280       return NULL;
 281     }
 282   elt = (struct var_map_elt *) *slot;
 283
 284   if (!elt && insert == INSERT)
 285     {
 286       field = make_node (FIELD_DECL);
 287       DECL_NAME (field) = DECL_NAME (decl);
 288
 289       if (use_pointer_in_frame (decl))
 290         {
 291           TREE_TYPE (field) = build_pointer_type (TREE_TYPE (decl));
 292           DECL_ALIGN (field) = TYPE_ALIGN (TREE_TYPE (field));
 293           DECL_NONADDRESSABLE_P (field) = 1;
 294         }
 295       else
 296         {
 297           TREE_TYPE (field) = TREE_TYPE (decl);
 298           DECL_SOURCE_LOCATION (field) = DECL_SOURCE_LOCATION (decl);
 299           DECL_ALIGN (field) = DECL_ALIGN (decl);
 300           DECL_USER_ALIGN (field) = DECL_USER_ALIGN (decl);
 301           TREE_ADDRESSABLE (field) = TREE_ADDRESSABLE (decl);
 302           DECL_NONADDRESSABLE_P (field) = !TREE_ADDRESSABLE (decl);
 303           TREE_THIS_VOLATILE (field) = TREE_THIS_VOLATILE (decl);
 304         }
 305
 306       insert_field_into_struct (get_frame_type (info), field);
 307
 308       elt = GGC_NEW (struct var_map_elt);
 309       elt->old = decl;
 310       elt->new = field;
 311       *slot = elt;
 312
 313       if (TREE_CODE (decl) == PARM_DECL)
 314         info->any_parm_remapped = true;
 315     }
 316   else
 317     field = elt ? elt->new : NULL;
 318
 319   return field;
 320 }
 321
 322 /* Build or return the variable that holds the static chain within
 323    INFO->CONTEXT.  This variable may only be used within INFO->CONTEXT.  */
 324
 325 static tree
 326 get_chain_decl (struct nesting_info *info)
 327 {
 328   tree decl = info->chain_decl;
 329   if (!decl)
 330     {
 331       tree type;
 332
 333       type = get_frame_type (info->outer);
 334       type = build_pointer_type (type);
 335
 336       /* Note that this variable is *not* entered into any BIND_EXPR;
 337          the construction of this variable is handled specially in
 338          expand_function_start and initialize_inlined_parameters.
 339          Note also that it's represented as a parameter.  This is more
 340          close to the truth, since the initial value does come from
 341          the caller.  */
 342       decl = build_decl (PARM_DECL, create_tmp_var_name ("CHAIN"), type);
 343       DECL_ARTIFICIAL (decl) = 1;
 344       DECL_IGNORED_P (decl) = 1;
 345       TREE_USED (decl) = 1;
 346       DECL_CONTEXT (decl) = info->context;
 347       DECL_ARG_TYPE (decl) = type;
 348
 349       /* Tell tree-inline.c that we never write to this variable, so
 350          it can copy-prop the replacement value immediately.  */
 351       TREE_READONLY (decl) = 1;
 352
 353       info->chain_decl = decl;
 354     }
 355   return decl;
 356 }
 357
 358 /* Build or return the field within the non-local frame state that holds
 359    the static chain for INFO->CONTEXT.  This is the way to walk back up
 360    multiple nesting levels.  */
 361
 362 static tree
 363 get_chain_field (struct nesting_info *info)
 364 {
 365   tree field = info->chain_field;
 366   if (!field)
 367     {
 368       tree type = build_pointer_type (get_frame_type (info->outer));
 369
 370       field = make_node (FIELD_DECL);
 371       DECL_NAME (field) = get_identifier ("__chain");
 372       TREE_TYPE (field) = type;
 373       DECL_ALIGN (field) = TYPE_ALIGN (type);
 374       DECL_NONADDRESSABLE_P (field) = 1;
 375
 376       insert_field_into_struct (get_frame_type (info), field);
 377
 378       info->chain_field = field;
 379     }
 380   return field;
 381 }
 382
 383 /* Copy EXP into a temporary.  Allocate the temporary in the context of
 384    INFO and insert the initialization statement before TSI.  */
 385
 386 static tree
 387 init_tmp_var (struct nesting_info *info, tree exp, tree_stmt_iterator *tsi)
 388 {
 389   tree t, stmt;
 390
 391   t = create_tmp_var_for (info, TREE_TYPE (exp), NULL);
 392   stmt = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (t), t, exp);
 393   SET_EXPR_LOCUS (stmt, EXPR_LOCUS (tsi_stmt (*tsi)));
 394   tsi_link_before (tsi, stmt, TSI_SAME_STMT);
 395
 396   return t;
 397 }
 398
 399 /* Similarly, but only do so to force EXP to satisfy is_gimple_val.  */
 400
 401 static tree
 402 tsi_gimplify_val (struct nesting_info *info, tree exp, tree_stmt_iterator *tsi)
 403 {
 404   if (is_gimple_val (exp))
 405     return exp;
 406   else
 407     return init_tmp_var (info, exp, tsi);
 408 }
 409
 410 /* Similarly, but copy from the temporary and insert the statement
 411    after the iterator.  */
 412
 413 static tree
 414 save_tmp_var (struct nesting_info *info, tree exp,
 415               tree_stmt_iterator *tsi)
 416 {
 417   tree t, stmt;
 418
 419   t = create_tmp_var_for (info, TREE_TYPE (exp), NULL);
 420   stmt = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (t), exp, t);
 421   SET_EXPR_LOCUS (stmt, EXPR_LOCUS (tsi_stmt (*tsi)));
 422   tsi_link_after (tsi, stmt, TSI_SAME_STMT);
 423
 424   return t;
 425 }
 426
 427 /* Build or return the type used to represent a nested function trampoline.  */
 428
 429 static GTY(()) tree trampoline_type;
 430
 431 static tree
 432 get_trampoline_type (void)
 433 {
 434   tree record, t;
 435   unsigned align, size;
 436
 437   if (trampoline_type)
 438     return trampoline_type;
 439
 440   align = TRAMPOLINE_ALIGNMENT;
 441   size = TRAMPOLINE_SIZE;
 442
 443   /* If we won't be able to guarantee alignment simply via TYPE_ALIGN,
 444      then allocate extra space so that we can do dynamic alignment.  */
 445   if (align > STACK_BOUNDARY)
 446     {
 447       size += ((align/BITS_PER_UNIT) - 1) & -(STACK_BOUNDARY/BITS_PER_UNIT);
 448       align = STACK_BOUNDARY;
 449     }
 450
 451   t = build_index_type (build_int_cst (NULL_TREE, size - 1));
 452   t = build_array_type (char_type_node, t);
 453   t = build_decl (FIELD_DECL, get_identifier ("__data"), t);
 454   DECL_ALIGN (t) = align;
 455   DECL_USER_ALIGN (t) = 1;
 456
 457   record = make_node (RECORD_TYPE);
 458   TYPE_NAME (record) = get_identifier ("__builtin_trampoline");
 459   TYPE_FIELDS (record) = t;
 460   layout_type (record);
 461
 462   return record;
 463 }
 464
 465 /* Given DECL, a nested function, find or create a field in the non-local
 466    frame structure for a trampoline for this function.  */
 467
 468 static tree
 469 lookup_tramp_for_decl (struct nesting_info *info, tree decl,
 470                        enum insert_option insert)
 471 {
 472   struct var_map_elt *elt, dummy;
 473   void **slot;
 474   tree field;
 475
 476   dummy.old = decl;
 477   slot = htab_find_slot (info->var_map, &dummy, insert);
 478   if (!slot)
 479     {
 480       gcc_assert (insert != INSERT);
 481       return NULL;
 482     }
 483   elt = (struct var_map_elt *) *slot;
 484
 485   if (!elt && insert == INSERT)
 486     {
 487       field = make_node (FIELD_DECL);
 488       DECL_NAME (field) = DECL_NAME (decl);
 489       TREE_TYPE (field) = get_trampoline_type ();
 490       TREE_ADDRESSABLE (field) = 1;
 491
 492       insert_field_into_struct (get_frame_type (info), field);
 493
 494       elt = GGC_NEW (struct var_map_elt);
 495       elt->old = decl;
 496       elt->new = field;
 497       *slot = elt;
 498
 499       info->any_tramp_created = true;
 500     }
 501   else
 502     field = elt ? elt->new : NULL;
 503
 504   return field;
 505 }
 506
 507 /* Build or return the field within the non-local frame state that holds
 508    the non-local goto "jmp_buf".  The buffer itself is maintained by the
 509    rtl middle-end as dynamic stack space is allocated.  */
 510
 511 static tree
 512 get_nl_goto_field (struct nesting_info *info)
 513 {
 514   tree field = info->nl_goto_field;
 515   if (!field)
 516     {
 517       unsigned size;
 518       tree type;
 519
 520       /* For __builtin_nonlocal_goto, we need N words.  The first is the
 521          frame pointer, the rest is for the target's stack pointer save
 522          area.  The number of words is controlled by STACK_SAVEAREA_MODE;
 523          not the best interface, but it'll do for now.  */
 524       if (Pmode == ptr_mode)
 525         type = ptr_type_node;
 526       else
 527         type = lang_hooks.types.type_for_mode (Pmode, 1);
 528
 529       size = GET_MODE_SIZE (STACK_SAVEAREA_MODE (SAVE_NONLOCAL));
 530       size = size / GET_MODE_SIZE (Pmode);
 531       size = size + 1;
 532
 533       type = build_array_type
 534         (type, build_index_type (build_int_cst (NULL_TREE, size)));
 535
 536       field = make_node (FIELD_DECL);
 537       DECL_NAME (field) = get_identifier ("__nl_goto_buf");
 538       TREE_TYPE (field) = type;
 539       DECL_ALIGN (field) = TYPE_ALIGN (type);
 540       TREE_ADDRESSABLE (field) = 1;
 541
 542       insert_field_into_struct (get_frame_type (info), field);
 543
 544       info->nl_goto_field = field;
 545     }
 546
 547   return field;
 548 }
 549 \f
 550 /* Helper function for walk_stmts.  Walk output operands of an ASM_EXPR.  */
 551
 552 static void
 553 walk_asm_expr (struct walk_stmt_info *wi, tree stmt)
 554 {
 555   int noutputs = list_length (ASM_OUTPUTS (stmt));
 556   const char **oconstraints
 557     = (const char **) alloca ((noutputs) * sizeof (const char *));
 558   int i;
 559   tree link;
 560   const char *constraint;
 561   bool allows_mem, allows_reg, is_inout;
 562
 563   wi->is_lhs = true;
 564   for (i=0, link = ASM_OUTPUTS (stmt); link; ++i, link = TREE_CHAIN (link))
 565     {
 566       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
 567       oconstraints[i] = constraint;
 568       parse_output_constraint (&constraint, i, 0, 0, &allows_mem,
 569                                &allows_reg, &is_inout);
 570
 571       wi->val_only = (allows_reg || !allows_mem);
 572       walk_tree (&TREE_VALUE (link), wi->callback, wi, NULL);
 573     }
 574
 575   for (link = ASM_INPUTS (stmt); link; link = TREE_CHAIN (link))
 576     {
 577       constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link)));
 578       parse_input_constraint (&constraint, 0, 0, noutputs, 0,
 579                               oconstraints, &allows_mem, &allows_reg);
 580
 581       wi->val_only = (allows_reg || !allows_mem);
 582       /* Although input "m" is not really a LHS, we need a lvalue.  */
 583       wi->is_lhs = !wi->val_only;
 584       walk_tree (&TREE_VALUE (link), wi->callback, wi, NULL);
 585     }
 586
 587   wi->is_lhs = false;
 588   wi->val_only = true;
 589 }
 590
 591 /* Iterate over all sub-statements of *TP calling walk_tree with
 592    WI->CALLBACK for every sub-expression in each statement found.  */
 593
 594 void
 595 walk_stmts (struct walk_stmt_info *wi, tree *tp)
 596 {
 597   tree t = *tp;
 598   int walk_subtrees;
 599
 600   if (!t)
 601     return;
 602
 603   if (wi->want_locations && EXPR_HAS_LOCATION (t))
 604     input_location = EXPR_LOCATION (t);
 605
 606   switch (TREE_CODE (t))
 607     {
 608     case STATEMENT_LIST:
 609       {
 610         tree_stmt_iterator i;
 611         for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
 612           {
 613             wi->tsi = i;
 614             walk_stmts (wi, tsi_stmt_ptr (i));
 615           }
 616       }
 617       break;
 618
 619     case COND_EXPR:
 620       walk_tree (&COND_EXPR_COND (t), wi->callback, wi, NULL);
 621       walk_stmts (wi, &COND_EXPR_THEN (t));
 622       walk_stmts (wi, &COND_EXPR_ELSE (t));
 623       break;
 624     case CATCH_EXPR:
 625       walk_stmts (wi, &CATCH_BODY (t));
 626       break;
 627     case EH_FILTER_EXPR:
 628       walk_stmts (wi, &EH_FILTER_FAILURE (t));
 629       break;
 630     case TRY_CATCH_EXPR:
 631     case TRY_FINALLY_EXPR:
 632       walk_stmts (wi, &TREE_OPERAND (t, 0));
 633       walk_stmts (wi, &TREE_OPERAND (t, 1));
 634       break;
 635
 636     case BIND_EXPR:
 637       if (wi->want_bind_expr)
 638         {
 639           walk_subtrees = 1;
 640           wi->callback (tp, &walk_subtrees, wi);
 641           if (!walk_subtrees)
 642             break;
 643         }
 644       walk_stmts (wi, &BIND_EXPR_BODY (t));
 645       break;
 646
 647     case RETURN_EXPR:
 648       if (wi->want_return_expr)
 649         {
 650           walk_subtrees = 1;
 651           wi->callback (tp, &walk_subtrees, wi);
 652           if (!walk_subtrees)
 653             break;
 654         }
 655       walk_stmts (wi, &TREE_OPERAND (t, 0));
 656       break;
 657
 658     case GIMPLE_MODIFY_STMT:
 659       /* A formal temporary lhs may use a COMPONENT_REF rhs.  */
 660       wi->val_only = !is_gimple_formal_tmp_var (GIMPLE_STMT_OPERAND (t, 0));
 661       walk_tree (&GIMPLE_STMT_OPERAND (t, 1), wi->callback, wi, NULL);
 662
 663       /* If the rhs is appropriate for a memory, we may use a
 664          COMPONENT_REF on the lhs.  */
 665       wi->val_only = !is_gimple_mem_rhs (GIMPLE_STMT_OPERAND (t, 1));
 666       wi->is_lhs = true;
 667       walk_tree (&GIMPLE_STMT_OPERAND (t, 0), wi->callback, wi, NULL);
 668
 669       wi->val_only = true;
 670       wi->is_lhs = false;
 671       break;
 672
 673     case ASM_EXPR:
 674       walk_asm_expr (wi, *tp);
 675       break;
 676
 677     default:
 678       wi->val_only = true;
 679       walk_tree (tp, wi->callback, wi, NULL);
 680       break;
 681     }
 682 }
 683
 684 /* Invoke CALLBACK on all statements of *STMT_P.  */
 685
 686 static void
 687 walk_body (walk_tree_fn callback, struct nesting_info *info, tree *stmt_p)
 688 {
 689   struct walk_stmt_info wi;
 690
 691   memset (&wi, 0, sizeof (wi));
 692   wi.callback = callback;
 693   wi.info = info;
 694   wi.val_only = true;
 695
 696   walk_stmts (&wi, stmt_p);
 697 }
 698
 699 /* Invoke CALLBACK on all statements of INFO->CONTEXT.  */
 700
 701 static inline void
 702 walk_function (walk_tree_fn callback, struct nesting_info *info)
 703 {
 704   walk_body (callback, info, &DECL_SAVED_TREE (info->context));
 705 }
 706
 707 /* Similarly for ROOT and all functions nested underneath, depth first.  */
 708
 709 static void
 710 walk_all_functions (walk_tree_fn callback, struct nesting_info *root)
 711 {
 712   do
 713     {
 714       if (root->inner)
 715         walk_all_functions (callback, root->inner);
 716       walk_function (callback, root);
 717       root = root->next;
 718     }
 719   while (root);
 720 }
 721 \f
 722 /* We have to check for a fairly pathological case.  The operands of function
 723    nested function are to be interpreted in the context of the enclosing
 724    function.  So if any are variably-sized, they will get remapped when the
 725    enclosing function is inlined.  But that remapping would also have to be
 726    done in the types of the PARM_DECLs of the nested function, meaning the
 727    argument types of that function will disagree with the arguments in the
 728    calls to that function.  So we'd either have to make a copy of the nested
 729    function corresponding to each time the enclosing function was inlined or
 730    add a VIEW_CONVERT_EXPR to each such operand for each call to the nested
 731    function.  The former is not practical.  The latter would still require
 732    detecting this case to know when to add the conversions.  So, for now at
 733    least, we don't inline such an enclosing function.
 734
 735    We have to do that check recursively, so here return indicating whether
 736    FNDECL has such a nested function.  ORIG_FN is the function we were
 737    trying to inline to use for checking whether any argument is variably
 738    modified by anything in it.
 739
 740    It would be better to do this in tree-inline.c so that we could give
 741    the appropriate warning for why a function can't be inlined, but that's
 742    too late since the nesting structure has already been flattened and
 743    adding a flag just to record this fact seems a waste of a flag.  */
 744
 745 static bool
 746 check_for_nested_with_variably_modified (tree fndecl, tree orig_fndecl)
 747 {
 748   struct cgraph_node *cgn = cgraph_node (fndecl);
 749   tree arg;
 750
 751   for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested)
 752     {
 753       for (arg = DECL_ARGUMENTS (cgn->decl); arg; arg = TREE_CHAIN (arg))
 754         if (variably_modified_type_p (TREE_TYPE (arg), 0), orig_fndecl)
 755           return true;
 756
 757       if (check_for_nested_with_variably_modified (cgn->decl, orig_fndecl))
 758         return true;
 759     }
 760
 761   return false;
 762 }
 763
 764 /* Construct our local datastructure describing the function nesting
 765    tree rooted by CGN.  */
 766
 767 static struct nesting_info *
 768 create_nesting_tree (struct cgraph_node *cgn)
 769 {
 770   struct nesting_info *info = GGC_CNEW (struct nesting_info);
 771   info->field_map = htab_create_ggc (7, var_map_hash, var_map_eq, ggc_free);
 772   info->var_map = htab_create_ggc (7, var_map_hash, var_map_eq, ggc_free);
 773   info->suppress_expansion = BITMAP_GGC_ALLOC ();
 774   info->context = cgn->decl;
 775
 776   for (cgn = cgn->nested; cgn ; cgn = cgn->next_nested)
 777     {
 778       struct nesting_info *sub = create_nesting_tree (cgn);
 779       sub->outer = info;
 780       sub->next = info->inner;
 781       info->inner = sub;
 782     }
 783
 784   /* See discussion at check_for_nested_with_variably_modified for a
 785      discussion of why this has to be here.  */
 786   if (check_for_nested_with_variably_modified (info->context, info->context))
 787     DECL_UNINLINABLE (info->context) = true;
 788
 789   return info;
 790 }
 791
 792 /* Return an expression computing the static chain for TARGET_CONTEXT
 793    from INFO->CONTEXT.  Insert any necessary computations before TSI.  */
 794
 795 static tree
 796 get_static_chain (struct nesting_info *info, tree target_context,
 797                   tree_stmt_iterator *tsi)
 798 {
 799   struct nesting_info *i;
 800   tree x;
 801
 802   if (info->context == target_context)
 803     {
 804       x = build_addr (info->frame_decl, target_context);
 805     }
 806   else
 807     {
 808       x = get_chain_decl (info);
 809
 810       for (i = info->outer; i->context != target_context; i = i->outer)
 811         {
 812           tree field = get_chain_field (i);
 813
 814           x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
 815           x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
 816           x = init_tmp_var (info, x, tsi);
 817         }
 818     }
 819
 820   return x;
 821 }
 822
 823 /* Return an expression referencing FIELD from TARGET_CONTEXT's non-local
 824    frame as seen from INFO->CONTEXT.  Insert any necessary computations
 825    before TSI.  */
 826
 827 static tree
 828 get_frame_field (struct nesting_info *info, tree target_context,
 829                  tree field, tree_stmt_iterator *tsi)
 830 {
 831   struct nesting_info *i;
 832   tree x;
 833
 834   if (info->context == target_context)
 835     {
 836       /* Make sure frame_decl gets created.  */
 837       (void) get_frame_type (info);
 838       x = info->frame_decl;
 839     }
 840   else
 841     {
 842       x = get_chain_decl (info);
 843
 844       for (i = info->outer; i->context != target_context; i = i->outer)
 845         {
 846           tree field = get_chain_field (i);
 847
 848           x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
 849           x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
 850           x = init_tmp_var (info, x, tsi);
 851         }
 852
 853       x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
 854     }
 855
 856   x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
 857   return x;
 858 }
 859
 860 /* A subroutine of convert_nonlocal_reference.  Create a local variable
 861    in the nested function with DECL_VALUE_EXPR set to reference the true
 862    variable in the parent function.  This is used both for debug info
 863    and in OpenMP lowering.  */
 864
 865 static tree
 866 get_nonlocal_debug_decl (struct nesting_info *info, tree decl)
 867 {
 868   struct var_map_elt *elt, dummy;
 869   tree target_context;
 870   struct nesting_info *i;
 871   tree x, field, new_decl;
 872   void **slot;
 873
 874   dummy.old = decl;
 875   slot = htab_find_slot (info->var_map, &dummy, INSERT);
 876   elt = *slot;
 877
 878   if (elt)
 879     return elt->new;
 880
 881   target_context = decl_function_context (decl);
 882
 883   /* A copy of the code in get_frame_field, but without the temporaries.  */
 884   if (info->context == target_context)
 885     {
 886       /* Make sure frame_decl gets created.  */
 887       (void) get_frame_type (info);
 888       x = info->frame_decl;
 889       i = info;
 890     }
 891   else
 892     {
 893       x = get_chain_decl (info);
 894       for (i = info->outer; i->context != target_context; i = i->outer)
 895         {
 896           field = get_chain_field (i);
 897           x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
 898           x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
 899         }
 900       x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
 901     }
 902
 903   field = lookup_field_for_decl (i, decl, INSERT);
 904   x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
 905   if (use_pointer_in_frame (decl))
 906     x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
 907
 908   /* ??? We should be remapping types as well, surely.  */
 909   new_decl = build_decl (VAR_DECL, DECL_NAME (decl), TREE_TYPE (decl));
 910   DECL_CONTEXT (new_decl) = info->context;
 911   DECL_SOURCE_LOCATION (new_decl) = DECL_SOURCE_LOCATION (decl);
 912   DECL_ARTIFICIAL (new_decl) = DECL_ARTIFICIAL (decl);
 913   DECL_IGNORED_P (new_decl) = DECL_IGNORED_P (decl);
 914   TREE_THIS_VOLATILE (new_decl) = TREE_THIS_VOLATILE (decl);
 915   TREE_SIDE_EFFECTS (new_decl) = TREE_SIDE_EFFECTS (decl);
 916   TREE_READONLY (new_decl) = TREE_READONLY (decl);
 917   TREE_ADDRESSABLE (new_decl) = TREE_ADDRESSABLE (decl);
 918   DECL_SEEN_IN_BIND_EXPR_P (new_decl) = 1;
 919
 920   SET_DECL_VALUE_EXPR (new_decl, x);
 921   DECL_HAS_VALUE_EXPR_P (new_decl) = 1;
 922
 923   elt = ggc_alloc (sizeof (*elt));
 924   elt->old = decl;
 925   elt->new = new_decl;
 926   *slot = elt;
 927
 928   TREE_CHAIN (new_decl) = info->debug_var_chain;
 929   info->debug_var_chain = new_decl;
 930
 931   return new_decl;
 932 }
 933
 934 /* Called via walk_function+walk_tree, rewrite all references to VAR
 935    and PARM_DECLs that belong to outer functions.
 936
 937    The rewrite will involve some number of structure accesses back up
 938    the static chain.  E.g. for a variable FOO up one nesting level it'll
 939    be CHAIN->FOO.  For two levels it'll be CHAIN->__chain->FOO.  Further
 940    indirections apply to decls for which use_pointer_in_frame is true.  */
 941
 942 static bool convert_nonlocal_omp_clauses (tree *, struct walk_stmt_info *);
 943
 944 static tree
 945 convert_nonlocal_reference (tree *tp, int *walk_subtrees, void *data)
 946 {
 947   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
 948   struct nesting_info *info = wi->info;
 949   tree t = *tp;
 950   tree save_local_var_chain;
 951   bitmap save_suppress;
 952
 953   *walk_subtrees = 0;
 954   switch (TREE_CODE (t))
 955     {
 956     case VAR_DECL:
 957       /* Non-automatic variables are never processed.  */
 958       if (TREE_STATIC (t) || DECL_EXTERNAL (t))
 959         break;
 960       /* FALLTHRU */
 961
 962     case PARM_DECL:
 963       if (decl_function_context (t) != info->context)
 964         {
 965           tree x;
 966           wi->changed = true;
 967
 968           x = get_nonlocal_debug_decl (info, t);
 969           if (!bitmap_bit_p (info->suppress_expansion, DECL_UID (t)))
 970             {
 971               tree target_context = decl_function_context (t);
 972               struct nesting_info *i;
 973               for (i = info->outer; i->context != target_context; i = i->outer)
 974                 continue;
 975               x = lookup_field_for_decl (i, t, INSERT);
 976               x = get_frame_field (info, target_context, x, &wi->tsi);
 977               if (use_pointer_in_frame (t))
 978                 {
 979                   x = init_tmp_var (info, x, &wi->tsi);
 980                   x = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (x)), x);
 981                 }
 982             }
 983
 984           if (wi->val_only)
 985             {
 986               if (wi->is_lhs)
 987                 x = save_tmp_var (info, x, &wi->tsi);
 988               else
 989                 x = init_tmp_var (info, x, &wi->tsi);
 990             }
 991
 992           *tp = x;
 993         }
 994       break;
 995
 996     case GOTO_EXPR:
 997       /* Don't walk non-local gotos for now.  */
 998       if (TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL)
 999         {
1000           *walk_subtrees = 1;
1001           wi->val_only = true;
1002           wi->is_lhs = false;
1003         }
1004       break;
1005
1006     case LABEL_DECL:
1007       /* We're taking the address of a label from a parent function, but
1008          this is not itself a non-local goto.  Mark the label such that it
1009          will not be deleted, much as we would with a label address in
1010          static storage.  */
1011       if (decl_function_context (t) != info->context)
1012         FORCED_LABEL (t) = 1;
1013       break;
1014
1015     case ADDR_EXPR:
1016       {
1017         bool save_val_only = wi->val_only;
1018
1019         wi->val_only = false;
1020         wi->is_lhs = false;
1021         wi->changed = false;
1022         walk_tree (&TREE_OPERAND (t, 0), convert_nonlocal_reference, wi, NULL);
1023         wi->val_only = true;
1024
1025         if (wi->changed)
1026           {
1027             tree save_context;
1028
1029             /* If we changed anything, then TREE_INVARIANT is be wrong,
1030                since we're no longer directly referencing a decl.  */
1031             save_context = current_function_decl;
1032             current_function_decl = info->context;
1033             recompute_tree_invariant_for_addr_expr (t);
1034             current_function_decl = save_context;
1035
1036             /* If the callback converted the address argument in a context
1037                where we only accept variables (and min_invariant, presumably),
1038                then compute the address into a temporary.  */
1039             if (save_val_only)
1040               *tp = tsi_gimplify_val (wi->info, t, &wi->tsi);
1041           }
1042       }
1043       break;
1044
1045     case REALPART_EXPR:
1046     case IMAGPART_EXPR:
1047     case COMPONENT_REF:
1048     case ARRAY_REF:
1049     case ARRAY_RANGE_REF:
1050     case BIT_FIELD_REF:
1051       /* Go down this entire nest and just look at the final prefix and
1052          anything that describes the references.  Otherwise, we lose track
1053          of whether a NOP_EXPR or VIEW_CONVERT_EXPR needs a simple value.  */
1054       wi->val_only = true;
1055       wi->is_lhs = false;
1056       for (; handled_component_p (t); tp = &TREE_OPERAND (t, 0), t = *tp)
1057         {
1058           if (TREE_CODE (t) == COMPONENT_REF)
1059             walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi,
1060                        NULL);
1061           else if (TREE_CODE (t) == ARRAY_REF
1062                    || TREE_CODE (t) == ARRAY_RANGE_REF)
1063             {
1064               walk_tree (&TREE_OPERAND (t, 1), convert_nonlocal_reference, wi,
1065                          NULL);
1066               walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi,
1067                          NULL);
1068               walk_tree (&TREE_OPERAND (t, 3), convert_nonlocal_reference, wi,
1069                          NULL);
1070             }
1071           else if (TREE_CODE (t) == BIT_FIELD_REF)
1072             {
1073               walk_tree (&TREE_OPERAND (t, 1), convert_nonlocal_reference, wi,
1074                          NULL);
1075               walk_tree (&TREE_OPERAND (t, 2), convert_nonlocal_reference, wi,
1076                          NULL);
1077             }
1078         }
1079       wi->val_only = false;
1080       walk_tree (tp, convert_nonlocal_reference, wi, NULL);
1081       break;
1082
1083     case OMP_PARALLEL:
1084       save_suppress = info->suppress_expansion;
1085       if (convert_nonlocal_omp_clauses (&OMP_PARALLEL_CLAUSES (t), wi))
1086         {
1087           tree c, decl;
1088           decl = get_chain_decl (info);
1089           c = build_omp_clause (OMP_CLAUSE_FIRSTPRIVATE);
1090           OMP_CLAUSE_DECL (c) = decl;
1091           OMP_CLAUSE_CHAIN (c) = OMP_PARALLEL_CLAUSES (t);
1092           OMP_PARALLEL_CLAUSES (t) = c;
1093         }
1094
1095       save_local_var_chain = info->new_local_var_chain;
1096       info->new_local_var_chain = NULL;
1097
1098       walk_body (convert_nonlocal_reference, info, &OMP_PARALLEL_BODY (t));
1099
1100       if (info->new_local_var_chain)
1101         declare_vars (info->new_local_var_chain, OMP_PARALLEL_BODY (t), false);
1102       info->new_local_var_chain = save_local_var_chain;
1103       info->suppress_expansion = save_suppress;
1104       break;
1105
1106     case OMP_FOR:
1107     case OMP_SECTIONS:
1108     case OMP_SINGLE:
1109       save_suppress = info->suppress_expansion;
1110       convert_nonlocal_omp_clauses (&OMP_CLAUSES (t), wi);
1111       walk_body (convert_nonlocal_reference, info, &OMP_BODY (t));
1112       info->suppress_expansion = save_suppress;
1113       break;
1114
1115     case OMP_SECTION:
1116     case OMP_MASTER:
1117     case OMP_ORDERED:
1118       walk_body (convert_nonlocal_reference, info, &OMP_BODY (t));
1119       break;
1120
1121     default:
1122       if (!IS_TYPE_OR_DECL_P (t))
1123         {
1124           *walk_subtrees = 1;
1125           wi->val_only = true;
1126           wi->is_lhs = false;
1127         }
1128       break;
1129     }
1130
1131   return NULL_TREE;
1132 }
1133
1134 static bool
1135 convert_nonlocal_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
1136 {
1137   struct nesting_info *info = wi->info;
1138   bool need_chain = false;
1139   tree clause, decl;
1140   int dummy;
1141   bitmap new_suppress;
1142
1143   new_suppress = BITMAP_GGC_ALLOC ();
1144   bitmap_copy (new_suppress, info->suppress_expansion);
1145
1146   for (clause = *pclauses; clause ; clause = OMP_CLAUSE_CHAIN (clause))
1147     {
1148       switch (OMP_CLAUSE_CODE (clause))
1149         {
1150         case OMP_CLAUSE_PRIVATE:
1151         case OMP_CLAUSE_FIRSTPRIVATE:
1152         case OMP_CLAUSE_LASTPRIVATE:
1153         case OMP_CLAUSE_REDUCTION:
1154         case OMP_CLAUSE_COPYPRIVATE:
1155         case OMP_CLAUSE_SHARED:
1156           decl = OMP_CLAUSE_DECL (clause);
1157           if (decl_function_context (decl) != info->context)
1158             {
1159               bitmap_set_bit (new_suppress, DECL_UID (decl));
1160               OMP_CLAUSE_DECL (clause) = get_nonlocal_debug_decl (info, decl);
1161               need_chain = true;
1162             }
1163           break;
1164
1165         case OMP_CLAUSE_SCHEDULE:
1166           if (OMP_CLAUSE_SCHEDULE_CHUNK_EXPR (clause) == NULL)
1167             break;
1168           /* FALLTHRU */
1169         case OMP_CLAUSE_IF:
1170         case OMP_CLAUSE_NUM_THREADS:
1171           wi->val_only = true;
1172           wi->is_lhs = false;
1173           convert_nonlocal_reference (&OMP_CLAUSE_OPERAND (clause, 0), &dummy,
1174                                       wi);
1175           break;
1176
1177         case OMP_CLAUSE_NOWAIT:
1178         case OMP_CLAUSE_ORDERED:
1179         case OMP_CLAUSE_DEFAULT:
1180         case OMP_CLAUSE_COPYIN:
1181           break;
1182
1183         default:
1184           gcc_unreachable ();
1185         }
1186     }
1187
1188   info->suppress_expansion = new_suppress;
1189
1190   return need_chain;
1191 }
1192
1193 /* A subroutine of convert_local_reference.  Create a local variable
1194    in the parent function with DECL_VALUE_EXPR set to reference the
1195    field in FRAME.  This is used both for debug info and in OpenMP
1196    lowering.  */
1197
1198 static tree
1199 get_local_debug_decl (struct nesting_info *info, tree decl, tree field)
1200 {
1201   struct var_map_elt *elt, dummy;
1202   tree x, new_decl;
1203   void **slot;
1204
1205   dummy.old = decl;
1206   slot = htab_find_slot (info->var_map, &dummy, INSERT);
1207   elt = *slot;
1208
1209   if (elt)
1210     return elt->new;
1211
1212   /* Make sure frame_decl gets created.  */
1213   (void) get_frame_type (info);
1214   x = info->frame_decl;
1215   x = build3 (COMPONENT_REF, TREE_TYPE (field), x, field, NULL_TREE);
1216
1217   new_decl = build_decl (VAR_DECL, DECL_NAME (decl), TREE_TYPE (decl));
1218   DECL_CONTEXT (new_decl) = info->context;
1219   DECL_SOURCE_LOCATION (new_decl) = DECL_SOURCE_LOCATION (decl);
1220   DECL_ARTIFICIAL (new_decl) = DECL_ARTIFICIAL (decl);
1221   DECL_IGNORED_P (new_decl) = DECL_IGNORED_P (decl);
1222   TREE_THIS_VOLATILE (new_decl) = TREE_THIS_VOLATILE (decl);
1223   TREE_SIDE_EFFECTS (new_decl) = TREE_SIDE_EFFECTS (decl);
1224   TREE_READONLY (new_decl) = TREE_READONLY (decl);
1225   TREE_ADDRESSABLE (new_decl) = TREE_ADDRESSABLE (decl);
1226   DECL_SEEN_IN_BIND_EXPR_P (new_decl) = 1;
1227
1228   SET_DECL_VALUE_EXPR (new_decl, x);
1229   DECL_HAS_VALUE_EXPR_P (new_decl) = 1;
1230
1231   elt = ggc_alloc (sizeof (*elt));
1232   elt->old = decl;
1233   elt->new = new_decl;
1234   *slot = elt;
1235
1236   TREE_CHAIN (new_decl) = info->debug_var_chain;
1237   info->debug_var_chain = new_decl;
1238
1239   /* Do not emit debug info twice.  */
1240   DECL_IGNORED_P (decl) = 1;
1241
1242   return new_decl;
1243 }
1244
1245 /* Called via walk_function+walk_tree, rewrite all references to VAR
1246    and PARM_DECLs that were referenced by inner nested functions.
1247    The rewrite will be a structure reference to the local frame variable.  */
1248
1249 static bool convert_local_omp_clauses (tree *, struct walk_stmt_info *);
1250
1251 static tree
1252 convert_local_reference (tree *tp, int *walk_subtrees, void *data)
1253 {
1254   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
1255   struct nesting_info *info = wi->info;
1256   tree t = *tp, field, x;
1257   bool save_val_only;
1258   tree save_local_var_chain;
1259   bitmap save_suppress;
1260
1261   *walk_subtrees = 0;
1262   switch (TREE_CODE (t))
1263     {
1264     case VAR_DECL:
1265       /* Non-automatic variables are never processed.  */
1266       if (TREE_STATIC (t) || DECL_EXTERNAL (t))
1267         break;
1268       /* FALLTHRU */
1269
1270     case PARM_DECL:
1271       if (decl_function_context (t) == info->context)
1272         {
1273           /* If we copied a pointer to the frame, then the original decl
1274              is used unchanged in the parent function.  */
1275           if (use_pointer_in_frame (t))
1276             break;
1277
1278           /* No need to transform anything if no child references the
1279              variable.  */
1280           field = lookup_field_for_decl (info, t, NO_INSERT);
1281           if (!field)
1282             break;
1283           wi->changed = true;
1284
1285           x = get_local_debug_decl (info, t, field);
1286           if (!bitmap_bit_p (info->suppress_expansion, DECL_UID (t)))
1287             x = get_frame_field (info, info->context, field, &wi->tsi);
1288
1289           if (wi->val_only)
1290             {
1291               if (wi->is_lhs)
1292                 x = save_tmp_var (info, x, &wi->tsi);
1293               else
1294                 x = init_tmp_var (info, x, &wi->tsi);
1295             }
1296
1297           *tp = x;
1298         }
1299       break;
1300
1301     case ADDR_EXPR:
1302       save_val_only = wi->val_only;
1303       wi->val_only = false;
1304       wi->is_lhs = false;
1305       wi->changed = false;
1306       walk_tree (&TREE_OPERAND (t, 0), convert_local_reference, wi, NULL);
1307       wi->val_only = save_val_only;
1308
1309       /* If we converted anything ... */
1310       if (wi->changed)
1311         {
1312           tree save_context;
1313
1314           /* Then the frame decl is now addressable.  */
1315           TREE_ADDRESSABLE (info->frame_decl) = 1;
1316
1317           save_context = current_function_decl;
1318           current_function_decl = info->context;
1319           recompute_tree_invariant_for_addr_expr (t);
1320           current_function_decl = save_context;
1321
1322           /* If we are in a context where we only accept values, then
1323              compute the address into a temporary.  */
1324           if (save_val_only)
1325             *tp = tsi_gimplify_val (wi->info, t, &wi->tsi);
1326         }
1327       break;
1328
1329     case REALPART_EXPR:
1330     case IMAGPART_EXPR:
1331     case COMPONENT_REF:
1332     case ARRAY_REF:
1333     case ARRAY_RANGE_REF:
1334     case BIT_FIELD_REF:
1335       /* Go down this entire nest and just look at the final prefix and
1336          anything that describes the references.  Otherwise, we lose track
1337          of whether a NOP_EXPR or VIEW_CONVERT_EXPR needs a simple value.  */
1338       save_val_only = wi->val_only;
1339       wi->val_only = true;
1340       wi->is_lhs = false;
1341       for (; handled_component_p (t); tp = &TREE_OPERAND (t, 0), t = *tp)
1342         {
1343           if (TREE_CODE (t) == COMPONENT_REF)
1344             walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi,
1345                        NULL);
1346           else if (TREE_CODE (t) == ARRAY_REF
1347                    || TREE_CODE (t) == ARRAY_RANGE_REF)
1348             {
1349               walk_tree (&TREE_OPERAND (t, 1), convert_local_reference, wi,
1350                          NULL);
1351               walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi,
1352                          NULL);
1353               walk_tree (&TREE_OPERAND (t, 3), convert_local_reference, wi,
1354                          NULL);
1355             }
1356           else if (TREE_CODE (t) == BIT_FIELD_REF)
1357             {
1358               walk_tree (&TREE_OPERAND (t, 1), convert_local_reference, wi,
1359                          NULL);
1360               walk_tree (&TREE_OPERAND (t, 2), convert_local_reference, wi,
1361                          NULL);
1362             }
1363         }
1364       wi->val_only = false;
1365       walk_tree (tp, convert_local_reference, wi, NULL);
1366       wi->val_only = save_val_only;
1367       break;
1368
1369     case OMP_PARALLEL:
1370       save_suppress = info->suppress_expansion;
1371       if (convert_local_omp_clauses (&OMP_PARALLEL_CLAUSES (t), wi))
1372         {
1373           tree c;
1374           (void) get_frame_type (info);
1375           c = build_omp_clause (OMP_CLAUSE_SHARED);
1376           OMP_CLAUSE_DECL (c) = info->frame_decl;
1377           OMP_CLAUSE_CHAIN (c) = OMP_PARALLEL_CLAUSES (t);
1378           OMP_PARALLEL_CLAUSES (t) = c;
1379         }
1380
1381       save_local_var_chain = info->new_local_var_chain;
1382       info->new_local_var_chain = NULL;
1383
1384       walk_body (convert_local_reference, info, &OMP_PARALLEL_BODY (t));
1385
1386       if (info->new_local_var_chain)
1387         declare_vars (info->new_local_var_chain, OMP_PARALLEL_BODY (t), false);
1388       info->new_local_var_chain = save_local_var_chain;
1389       info->suppress_expansion = save_suppress;
1390       break;
1391
1392     case OMP_FOR:
1393     case OMP_SECTIONS:
1394     case OMP_SINGLE:
1395       save_suppress = info->suppress_expansion;
1396       convert_local_omp_clauses (&OMP_CLAUSES (t), wi);
1397       walk_body (convert_local_reference, info, &OMP_BODY (t));
1398       info->suppress_expansion = save_suppress;
1399       break;
1400
1401     case OMP_SECTION:
1402     case OMP_MASTER:
1403     case OMP_ORDERED:
1404       walk_body (convert_local_reference, info, &OMP_BODY (t));
1405       break;
1406
1407     default:
1408       if (!IS_TYPE_OR_DECL_P (t))
1409         {
1410           *walk_subtrees = 1;
1411           wi->val_only = true;
1412           wi->is_lhs = false;
1413         }
1414       break;
1415     }
1416
1417   return NULL_TREE;
1418 }
1419
1420 static bool
1421 convert_local_omp_clauses (tree *pclauses, struct walk_stmt_info *wi)
1422 {
1423   struct nesting_info *info = wi->info;
1424   bool need_frame = false;
1425   tree clause, decl;
1426   int dummy;
1427   bitmap new_suppress;
1428
1429   new_suppress = BITMAP_GGC_ALLOC ();
1430   bitmap_copy (new_suppress, info->suppress_expansion);
1431
1432   for (clause = *pclauses; clause ; clause = OMP_CLAUSE_CHAIN (clause))
1433     {
1434       switch (OMP_CLAUSE_CODE (clause))
1435         {
1436         case OMP_CLAUSE_PRIVATE:
1437         case OMP_CLAUSE_FIRSTPRIVATE:
1438         case OMP_CLAUSE_LASTPRIVATE:
1439         case OMP_CLAUSE_REDUCTION:
1440         case OMP_CLAUSE_COPYPRIVATE:
1441         case OMP_CLAUSE_SHARED:
1442           decl = OMP_CLAUSE_DECL (clause);
1443           if (decl_function_context (decl) == info->context
1444               && !use_pointer_in_frame (decl))
1445             {
1446               tree field = lookup_field_for_decl (info, decl, NO_INSERT);
1447               if (field)
1448                 {
1449                   bitmap_set_bit (new_suppress, DECL_UID (decl));
1450                   OMP_CLAUSE_DECL (clause)
1451                     = get_local_debug_decl (info, decl, field);
1452                   need_frame = true;
1453                 }
1454             }
1455           break;
1456
1457         case OMP_CLAUSE_SCHEDULE:
1458           if (OMP_CLAUSE_SCHEDULE_CHUNK_EXPR (clause) == NULL)
1459             break;
1460           /* FALLTHRU */
1461         case OMP_CLAUSE_IF:
1462         case OMP_CLAUSE_NUM_THREADS:
1463           wi->val_only = true;
1464           wi->is_lhs = false;
1465           convert_local_reference (&OMP_CLAUSE_OPERAND (clause, 0), &dummy, wi);
1466           break;
1467
1468         case OMP_CLAUSE_NOWAIT:
1469         case OMP_CLAUSE_ORDERED:
1470         case OMP_CLAUSE_DEFAULT:
1471         case OMP_CLAUSE_COPYIN:
1472           break;
1473
1474         default:
1475           gcc_unreachable ();
1476         }
1477     }
1478
1479   info->suppress_expansion = new_suppress;
1480
1481   return need_frame;
1482 }
1483
1484 /* Called via walk_function+walk_tree, rewrite all GOTO_EXPRs that
1485    reference labels from outer functions.  The rewrite will be a
1486    call to __builtin_nonlocal_goto.  */
1487
1488 static tree
1489 convert_nl_goto_reference (tree *tp, int *walk_subtrees, void *data)
1490 {
1491   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
1492   struct nesting_info *info = wi->info, *i;
1493   tree t = *tp, label, new_label, target_context, x, arg, field;
1494   struct var_map_elt *elt, dummy;
1495   void **slot;
1496
1497   *walk_subtrees = 0;
1498   if (TREE_CODE (t) != GOTO_EXPR)
1499     return NULL_TREE;
1500   label = GOTO_DESTINATION (t);
1501   if (TREE_CODE (label) != LABEL_DECL)
1502     return NULL_TREE;
1503   target_context = decl_function_context (label);
1504   if (target_context == info->context)
1505     return NULL_TREE;
1506
1507   for (i = info->outer; target_context != i->context; i = i->outer)
1508     continue;
1509
1510   /* The original user label may also be use for a normal goto, therefore
1511      we must create a new label that will actually receive the abnormal
1512      control transfer.  This new label will be marked LABEL_NONLOCAL; this
1513      mark will trigger proper behavior in the cfg, as well as cause the
1514      (hairy target-specific) non-local goto receiver code to be generated
1515      when we expand rtl.  Enter this association into var_map so that we
1516      can insert the new label into the IL during a second pass.  */
1517   dummy.old = label;
1518   slot = htab_find_slot (i->var_map, &dummy, INSERT);
1519   elt = (struct var_map_elt *) *slot;
1520   if (elt == NULL)
1521     {
1522       new_label = create_artificial_label ();
1523       DECL_NONLOCAL (new_label) = 1;
1524
1525       elt = GGC_NEW (struct var_map_elt);
1526       elt->old = label;
1527       elt->new = new_label;
1528       *slot = elt;
1529     }
1530   else
1531     new_label = elt->new;
1532
1533   /* Build: __builtin_nl_goto(new_label, &chain->nl_goto_field).  */
1534   field = get_nl_goto_field (i);
1535   x = get_frame_field (info, target_context, field, &wi->tsi);
1536   x = build_addr (x, target_context);
1537   x = tsi_gimplify_val (info, x, &wi->tsi);
1538   arg = tree_cons (NULL, x, NULL);
1539   x = build_addr (new_label, target_context);
1540   arg = tree_cons (NULL, x, arg);
1541   x = implicit_built_in_decls[BUILT_IN_NONLOCAL_GOTO];
1542   x = build_function_call_expr (x, arg);
1543
1544   SET_EXPR_LOCUS (x, EXPR_LOCUS (tsi_stmt (wi->tsi)));
1545   *tsi_stmt_ptr (wi->tsi) = x;
1546
1547   return NULL_TREE;
1548 }
1549
1550 /* Called via walk_function+walk_tree, rewrite all LABEL_EXPRs that
1551    are referenced via nonlocal goto from a nested function.  The rewrite
1552    will involve installing a newly generated DECL_NONLOCAL label, and
1553    (potentially) a branch around the rtl gunk that is assumed to be
1554    attached to such a label.  */
1555
1556 static tree
1557 convert_nl_goto_receiver (tree *tp, int *walk_subtrees, void *data)
1558 {
1559   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
1560   struct nesting_info *info = wi->info;
1561   tree t = *tp, label, new_label, x;
1562   struct var_map_elt *elt, dummy;
1563   tree_stmt_iterator tmp_tsi;
1564
1565   *walk_subtrees = 0;
1566   if (TREE_CODE (t) != LABEL_EXPR)
1567     return NULL_TREE;
1568   label = LABEL_EXPR_LABEL (t);
1569
1570   dummy.old = label;
1571   elt = (struct var_map_elt *) htab_find (info->var_map, &dummy);
1572   if (!elt)
1573     return NULL_TREE;
1574   new_label = elt->new;
1575
1576   /* If there's any possibility that the previous statement falls through,
1577      then we must branch around the new non-local label.  */
1578   tmp_tsi = wi->tsi;
1579   tsi_prev (&tmp_tsi);
1580   if (tsi_end_p (tmp_tsi) || block_may_fallthru (tsi_stmt (tmp_tsi)))
1581     {
1582       x = build1 (GOTO_EXPR, void_type_node, label);
1583       tsi_link_before (&wi->tsi, x, TSI_SAME_STMT);
1584     }
1585   x = build1 (LABEL_EXPR, void_type_node, new_label);
1586   tsi_link_before (&wi->tsi, x, TSI_SAME_STMT);
1587
1588   return NULL_TREE;
1589 }
1590
1591 /* Called via walk_function+walk_tree, rewrite all references to addresses
1592    of nested functions that require the use of trampolines.  The rewrite
1593    will involve a reference a trampoline generated for the occasion.  */
1594
1595 static tree
1596 convert_tramp_reference (tree *tp, int *walk_subtrees, void *data)
1597 {
1598   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
1599   struct nesting_info *info = wi->info, *i;
1600   tree t = *tp, decl, target_context, x, arg;
1601
1602   *walk_subtrees = 0;
1603   switch (TREE_CODE (t))
1604     {
1605     case ADDR_EXPR:
1606       /* Build
1607            T.1 = &CHAIN->tramp;
1608            T.2 = __builtin_adjust_trampoline (T.1);
1609            T.3 = (func_type)T.2;
1610       */
1611
1612       decl = TREE_OPERAND (t, 0);
1613       if (TREE_CODE (decl) != FUNCTION_DECL)
1614         break;
1615
1616       /* Only need to process nested functions.  */
1617       target_context = decl_function_context (decl);
1618       if (!target_context)
1619         break;
1620
1621       /* If the nested function doesn't use a static chain, then
1622          it doesn't need a trampoline.  */
1623       if (DECL_NO_STATIC_CHAIN (decl))
1624         break;
1625
1626       /* Lookup the immediate parent of the callee, as that's where
1627          we need to insert the trampoline.  */
1628       for (i = info; i->context != target_context; i = i->outer)
1629         continue;
1630       x = lookup_tramp_for_decl (i, decl, INSERT);
1631
1632       /* Compute the address of the field holding the trampoline.  */
1633       x = get_frame_field (info, target_context, x, &wi->tsi);
1634       x = build_addr (x, target_context);
1635       x = tsi_gimplify_val (info, x, &wi->tsi);
1636       arg = tree_cons (NULL, x, NULL);
1637
1638       /* Do machine-specific ugliness.  Normally this will involve
1639          computing extra alignment, but it can really be anything.  */
1640       x = implicit_built_in_decls[BUILT_IN_ADJUST_TRAMPOLINE];
1641       x = build_function_call_expr (x, arg);
1642       x = init_tmp_var (info, x, &wi->tsi);
1643
1644       /* Cast back to the proper function type.  */
1645       x = build1 (NOP_EXPR, TREE_TYPE (t), x);
1646       x = init_tmp_var (info, x, &wi->tsi);
1647
1648       *tp = x;
1649       break;
1650
1651     case CALL_EXPR:
1652       /* Only walk call arguments, lest we generate trampolines for
1653          direct calls.  */
1654       walk_tree (&TREE_OPERAND (t, 1), convert_tramp_reference, wi, NULL);
1655       break;
1656
1657     default:
1658       if (!IS_TYPE_OR_DECL_P (t))
1659         *walk_subtrees = 1;
1660       break;
1661     }
1662
1663   return NULL_TREE;
1664 }
1665
1666 /* Called via walk_function+walk_tree, rewrite all CALL_EXPRs that
1667    reference nested functions to make sure that the static chain is
1668    set up properly for the call.  */
1669
1670 static tree
1671 convert_call_expr (tree *tp, int *walk_subtrees, void *data)
1672 {
1673   struct walk_stmt_info *wi = (struct walk_stmt_info *) data;
1674   struct nesting_info *info = wi->info;
1675   tree t = *tp, decl, target_context;
1676   char save_static_chain_added;
1677   int i;
1678
1679   *walk_subtrees = 0;
1680   switch (TREE_CODE (t))
1681     {
1682     case CALL_EXPR:
1683       decl = get_callee_fndecl (t);
1684       if (!decl)
1685         break;
1686       target_context = decl_function_context (decl);
1687       if (target_context && !DECL_NO_STATIC_CHAIN (decl))
1688         {
1689           TREE_OPERAND (t, 2)
1690             = get_static_chain (info, target_context, &wi->tsi);
1691           info->static_chain_added
1692             |= (1 << (info->context != target_context));
1693         }
1694       break;
1695
1696     case RETURN_EXPR:
1697     case GIMPLE_MODIFY_STMT:
1698     case WITH_SIZE_EXPR:
1699       /* Only return modify and with_size_expr may contain calls.  */
1700       *walk_subtrees = 1;
1701       break;
1702
1703     case OMP_PARALLEL:
1704       save_static_chain_added = info->static_chain_added;
1705       info->static_chain_added = 0;
1706       walk_body (convert_call_expr, info, &OMP_PARALLEL_BODY (t));
1707       for (i = 0; i < 2; i++)
1708         {
1709           tree c, decl;
1710           if ((info->static_chain_added & (1 << i)) == 0)
1711             continue;
1712           decl = i ? get_chain_decl (info) : info->frame_decl;
1713           /* Don't add CHAIN.* or FRAME.* twice.  */
1714           for (c = OMP_PARALLEL_CLAUSES (t); c; c = OMP_CLAUSE_CHAIN (c))
1715             if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
1716                  || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_SHARED)
1717                 && OMP_CLAUSE_DECL (c) == decl)
1718               break;
1719           if (c == NULL)
1720             {
1721               c = build_omp_clause (OMP_CLAUSE_FIRSTPRIVATE);
1722               OMP_CLAUSE_DECL (c) = decl;
1723               OMP_CLAUSE_CHAIN (c) = OMP_PARALLEL_CLAUSES (t);
1724               OMP_PARALLEL_CLAUSES (t) = c;
1725             }
1726         }
1727       info->static_chain_added |= save_static_chain_added;
1728       break;
1729
1730     case OMP_FOR:
1731     case OMP_SECTIONS:
1732     case OMP_SECTION:
1733     case OMP_SINGLE:
1734     case OMP_MASTER:
1735     case OMP_ORDERED:
1736     case OMP_CRITICAL:
1737       walk_body (convert_call_expr, info, &OMP_BODY (t));
1738       break;
1739
1740     default:
1741       break;
1742     }
1743
1744   return NULL_TREE;
1745 }
1746
1747 /* Walk the nesting tree starting with ROOT, depth first.  Convert all
1748    trampolines and call expressions.  On the way back up, determine if
1749    a nested function actually uses its static chain; if not, remember that.  */
1750
1751 static void
1752 convert_all_function_calls (struct nesting_info *root)
1753 {
1754   do
1755     {
1756       if (root->inner)
1757         convert_all_function_calls (root->inner);
1758
1759       walk_function (convert_tramp_reference, root);
1760       walk_function (convert_call_expr, root);
1761
1762       /* If the function does not use a static chain, then remember that.  */
1763       if (root->outer && !root->chain_decl && !root->chain_field)
1764         DECL_NO_STATIC_CHAIN (root->context) = 1;
1765       else
1766         gcc_assert (!DECL_NO_STATIC_CHAIN (root->context));
1767
1768       root = root->next;
1769     }
1770   while (root);
1771 }
1772
1773 /* Do "everything else" to clean up or complete state collected by the
1774    various walking passes -- lay out the types and decls, generate code
1775    to initialize the frame decl, store critical expressions in the
1776    struct function for rtl to find.  */
1777
1778 static void
1779 finalize_nesting_tree_1 (struct nesting_info *root)
1780 {
1781   tree stmt_list = NULL;
1782   tree context = root->context;
1783   struct function *sf;
1784
1785   /* If we created a non-local frame type or decl, we need to lay them
1786      out at this time.  */
1787   if (root->frame_type)
1788     {
1789       /* In some cases the frame type will trigger the -Wpadded warning.
1790          This is not helpful; suppress it. */
1791       int save_warn_padded = warn_padded;
1792       warn_padded = 0;
1793       layout_type (root->frame_type);
1794       warn_padded = save_warn_padded;
1795       layout_decl (root->frame_decl, 0);
1796     }
1797
1798   /* If any parameters were referenced non-locally, then we need to
1799      insert a copy.  Likewise, if any variables were referenced by
1800      pointer, we need to initialize the address.  */
1801   if (root->any_parm_remapped)
1802     {
1803       tree p;
1804       for (p = DECL_ARGUMENTS (context); p ; p = TREE_CHAIN (p))
1805         {
1806           tree field, x, y;
1807
1808           field = lookup_field_for_decl (root, p, NO_INSERT);
1809           if (!field)
1810             continue;
1811
1812           if (use_pointer_in_frame (p))
1813             x = build_addr (p, context);
1814           else
1815             x = p;
1816
1817           y = build3 (COMPONENT_REF, TREE_TYPE (field),
1818                       root->frame_decl, field, NULL_TREE);
1819           x = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (field), y, x);
1820           append_to_statement_list (x, &stmt_list);
1821         }
1822     }
1823
1824   /* If a chain_field was created, then it needs to be initialized
1825      from chain_decl.  */
1826   if (root->chain_field)
1827     {
1828       tree x = build3 (COMPONENT_REF, TREE_TYPE (root->chain_field),
1829                        root->frame_decl, root->chain_field, NULL_TREE);
1830       x = build2 (GIMPLE_MODIFY_STMT, TREE_TYPE (x), x, get_chain_decl (root));
1831       append_to_statement_list (x, &stmt_list);
1832     }
1833
1834   /* If trampolines were created, then we need to initialize them.  */
1835   if (root->any_tramp_created)
1836     {
1837       struct nesting_info *i;
1838       for (i = root->inner; i ; i = i->next)
1839         {
1840           tree arg, x, field;
1841
1842           field = lookup_tramp_for_decl (root, i->context, NO_INSERT);
1843           if (!field)
1844             continue;
1845
1846           if (DECL_NO_STATIC_CHAIN (i->context))
1847             x = null_pointer_node;
1848           else
1849             x = build_addr (root->frame_decl, context);
1850           arg = tree_cons (NULL, x, NULL);
1851
1852           x = build_addr (i->context, context);
1853           arg = tree_cons (NULL, x, arg);
1854
1855           x = build3 (COMPONENT_REF, TREE_TYPE (field),
1856                       root->frame_decl, field, NULL_TREE);
1857           x = build_addr (x, context);
1858           arg = tree_cons (NULL, x, arg);
1859
1860           x = implicit_built_in_decls[BUILT_IN_INIT_TRAMPOLINE];
1861           x = build_function_call_expr (x, arg);
1862
1863           append_to_statement_list (x, &stmt_list);
1864         }
1865     }
1866
1867   /* If we created initialization statements, insert them.  */
1868   if (stmt_list)
1869     {
1870       annotate_all_with_locus (&stmt_list,
1871                                DECL_SOURCE_LOCATION (context));
1872       append_to_statement_list (BIND_EXPR_BODY (DECL_SAVED_TREE (context)),
1873                                 &stmt_list);
1874       BIND_EXPR_BODY (DECL_SAVED_TREE (context)) = stmt_list;
1875     }
1876
1877   /* If a chain_decl was created, then it needs to be registered with
1878      struct function so that it gets initialized from the static chain
1879      register at the beginning of the function.  */
1880   sf = DECL_STRUCT_FUNCTION (root->context);
1881   sf->static_chain_decl = root->chain_decl;
1882
1883   /* Similarly for the non-local goto save area.  */
1884   if (root->nl_goto_field)
1885     {
1886       sf->nonlocal_goto_save_area
1887         = get_frame_field (root, context, root->nl_goto_field, NULL);
1888       sf->has_nonlocal_label = 1;
1889     }
1890
1891   /* Make sure all new local variables get inserted into the
1892      proper BIND_EXPR.  */
1893   if (root->new_local_var_chain)
1894     declare_vars (root->new_local_var_chain, DECL_SAVED_TREE (root->context),
1895                   false);
1896   if (root->debug_var_chain)
1897     declare_vars (root->debug_var_chain, DECL_SAVED_TREE (root->context),
1898                   true);
1899
1900   /* Dump the translated tree function.  */
1901   dump_function (TDI_nested, root->context);
1902 }
1903
1904 static void
1905 finalize_nesting_tree (struct nesting_info *root)
1906 {
1907   do
1908     {
1909       if (root->inner)
1910         finalize_nesting_tree (root->inner);
1911       finalize_nesting_tree_1 (root);
1912       root = root->next;
1913     }
1914   while (root);
1915 }
1916
1917 /* Unnest the nodes and pass them to cgraph.  */
1918
1919 static void
1920 unnest_nesting_tree_1 (struct nesting_info *root)
1921 {
1922   struct cgraph_node *node = cgraph_node (root->context);
1923
1924   /* For nested functions update the cgraph to reflect unnesting.
1925      We also delay finalizing of these functions up to this point.  */
1926   if (node->origin)
1927     {
1928        cgraph_unnest_node (cgraph_node (root->context));
1929        cgraph_finalize_function (root->context, true);
1930     }
1931 }
1932
1933 static void
1934 unnest_nesting_tree (struct nesting_info *root)
1935 {
1936   do
1937     {
1938       if (root->inner)
1939         unnest_nesting_tree (root->inner);
1940       unnest_nesting_tree_1 (root);
1941       root = root->next;
1942     }
1943   while (root);
1944 }
1945
1946 /* Free the data structures allocated during this pass.  */
1947
1948 static void
1949 free_nesting_tree (struct nesting_info *root)
1950 {
1951   struct nesting_info *next;
1952   do
1953     {
1954       if (root->inner)
1955         free_nesting_tree (root->inner);
1956       htab_delete (root->var_map);
1957       next = root->next;
1958       ggc_free (root);
1959       root = next;
1960     }
1961   while (root);
1962 }
1963
1964 static GTY(()) struct nesting_info *root;
1965
1966 /* Main entry point for this pass.  Process FNDECL and all of its nested
1967    subroutines and turn them into something less tightly bound.  */
1968
1969 void
1970 lower_nested_functions (tree fndecl)
1971 {
1972   struct cgraph_node *cgn;
1973
1974   /* If there are no nested functions, there's nothing to do.  */
1975   cgn = cgraph_node (fndecl);
1976   if (!cgn->nested)
1977     return;
1978
1979   root = create_nesting_tree (cgn);
1980   walk_all_functions (convert_nonlocal_reference, root);
1981   walk_all_functions (convert_local_reference, root);
1982   walk_all_functions (convert_nl_goto_reference, root);
1983   walk_all_functions (convert_nl_goto_receiver, root);
1984   convert_all_function_calls (root);
1985   finalize_nesting_tree (root);
1986   unnest_nesting_tree (root);
1987   free_nesting_tree (root);
1988   root = NULL;
1989 }
1990
1991 #include "gt-tree-nested.h"