gcc/c-semantics.c

   1 /* This file contains the definitions and documentation for the common
   2    tree codes used in the GNU C and C++ compilers (see c-common.def
   3    for the standard codes).
   4    Copyright (C) 2000, 2001 Free Software Foundation, Inc.
   5    Written by Benjamin Chelf (chelf@codesourcery.com).
   6
   7 This file is part of GNU CC.
   8
   9 GNU CC is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 2, or (at your option)
  12 any later version.
  13
  14 GNU CC is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GNU CC; see the file COPYING.  If not, write to
  21 the Free Software Foundation, 59 Temple Place - Suite 330,
  22 Boston, MA 02111-1307, USA.  */
  23
  24 #include "config.h"
  25 #include "system.h"
  26 #include "tree.h"
  27 #include "function.h"
  28 #include "splay-tree.h"
  29 #include "varray.h"
  30 #include "c-common.h"
  31 #include "except.h"
  32 #include "toplev.h"
  33 #include "flags.h"
  34 #include "ggc.h"
  35 #include "rtl.h"
  36 #include "expr.h"
  37 #include "output.h"
  38 #include "timevar.h"
  39
  40 /* If non-NULL, the address of a language-specific function for
  41    expanding statements.  */
  42 void (*lang_expand_stmt) PARAMS ((tree));
  43
  44 /* If non-NULL, the address of a language-specific function for
  45    expanding a DECL_STMT.  After the language-independent cases are
  46    handled, this function will be called.  If this function is not
  47    defined, it is assumed that declarations other than those for
  48    variables and labels do not require any RTL generation.  */
  49 void (*lang_expand_decl_stmt) PARAMS ((tree));
  50
  51 /* Create an empty statement tree rooted at T.  */
  52
  53 void
  54 begin_stmt_tree (t)
  55      tree *t;
  56 {
  57   /* We create a trivial EXPR_STMT so that last_tree is never NULL in
  58      what follows.  We remove the extraneous statement in
  59      finish_stmt_tree.  */
  60   *t = build_nt (EXPR_STMT, void_zero_node);
  61   last_tree = *t;
  62   last_expr_type = NULL_TREE;
  63 }
  64
  65 /* T is a statement.  Add it to the statement-tree.  */
  66
  67 tree
  68 add_stmt (t)
  69      tree t;
  70 {
  71   /* Add T to the statement-tree.  */
  72   TREE_CHAIN (last_tree) = t;
  73   last_tree = t;
  74
  75   /* When we expand a statement-tree, we must know whether or not the
  76      statements are full-expressions.  We record that fact here.  */
  77   STMT_IS_FULL_EXPR_P (last_tree) = stmts_are_full_exprs_p ();
  78
  79   /* Keep track of the number of statements in this function.  */
  80   if (current_function_decl)
  81     ++DECL_NUM_STMTS (current_function_decl);
  82
  83   return t;
  84 }
  85
  86 /* Create a declaration statement for the declaration given by the
  87    DECL.  */
  88
  89 void
  90 add_decl_stmt (decl)
  91      tree decl;
  92 {
  93   tree decl_stmt;
  94
  95   /* We need the type to last until instantiation time.  */
  96   decl_stmt = build_stmt (DECL_STMT, decl);
  97   add_stmt (decl_stmt);
  98 }
  99
 100 /* Add a scope-statement to the statement-tree.  BEGIN_P indicates
 101    whether this statements opens or closes a scope.  PARTIAL_P is true
 102    for a partial scope, i.e, the scope that begins after a label when
 103    an object that needs a cleanup is created.  If BEGIN_P is nonzero,
 104    returns a new TREE_LIST representing the top of the SCOPE_STMT
 105    stack.  The TREE_PURPOSE is the new SCOPE_STMT.  If BEGIN_P is
 106    zero, returns a TREE_LIST whose TREE_VALUE is the new SCOPE_STMT,
 107    and whose TREE_PURPOSE is the matching SCOPE_STMT with
 108    SCOPE_BEGIN_P set.  */
 109
 110 tree
 111 add_scope_stmt (begin_p, partial_p)
 112      int begin_p;
 113      int partial_p;
 114 {
 115   tree *stack_ptr = current_scope_stmt_stack ();
 116   tree ss;
 117   tree top = *stack_ptr;
 118
 119   /* Build the statement.  */
 120   ss = build_stmt (SCOPE_STMT, NULL_TREE);
 121   SCOPE_BEGIN_P (ss) = begin_p;
 122   SCOPE_PARTIAL_P (ss) = partial_p;
 123
 124   /* Keep the scope stack up to date.  */
 125   if (begin_p)
 126     {
 127       top = tree_cons (ss, NULL_TREE, top);
 128       *stack_ptr = top;
 129     }
 130   else
 131     {
 132       TREE_VALUE (top) = ss;
 133       *stack_ptr = TREE_CHAIN (top);
 134     }
 135
 136   /* Add the new statement to the statement-tree.  */
 137   add_stmt (ss);
 138
 139   return top;
 140 }
 141
 142 /* Finish the statement tree rooted at T.  */
 143
 144 void
 145 finish_stmt_tree (t)
 146      tree *t;
 147 {
 148   tree stmt;
 149
 150   /* Remove the fake extra statement added in begin_stmt_tree.  */
 151   stmt = TREE_CHAIN (*t);
 152   *t = stmt;
 153   last_tree = NULL_TREE;
 154
 155   if (cfun && stmt)
 156     {
 157       /* The line-number recorded in the outermost statement in a function
 158          is the line number of the end of the function.  */
 159       STMT_LINENO (stmt) = lineno;
 160       STMT_LINENO_FOR_FN_P (stmt) = 1;
 161     }
 162 }
 163
 164 /* Build a generic statement based on the given type of node and
 165    arguments. Similar to `build_nt', except that we set
 166    STMT_LINENO to be the current line number.  */
 167 /* ??? This should be obsolete with the lineno_stmt productions
 168    in the grammar.  */
 169
 170 tree
 171 build_stmt VPARAMS ((enum tree_code code, ...))
 172 {
 173 #ifndef ANSI_PROTOTYPES
 174   enum tree_code code;
 175 #endif
 176   va_list p;
 177   register tree t;
 178   register int length;
 179   register int i;
 180
 181   VA_START (p, code);
 182
 183 #ifndef ANSI_PROTOTYPES
 184   code = va_arg (p, enum tree_code);
 185 #endif
 186
 187   t = make_node (code);
 188   length = TREE_CODE_LENGTH (code);
 189   STMT_LINENO (t) = lineno;
 190
 191   for (i = 0; i < length; i++)
 192     TREE_OPERAND (t, i) = va_arg (p, tree);
 193
 194   va_end (p);
 195   return t;
 196 }
 197
 198 /* Some statements, like for-statements or if-statements, require a
 199    condition.  This condition can be a declaration.  If T is such a
 200    declaration it is processed, and an expression appropriate to use
 201    as the condition is returned.  Otherwise, T itself is returned.  */
 202
 203 tree
 204 expand_cond (t)
 205      tree t;
 206 {
 207   if (t && TREE_CODE (t) == TREE_LIST)
 208     {
 209       expand_stmt (TREE_PURPOSE (t));
 210       return TREE_VALUE (t);
 211     }
 212   else
 213     return t;
 214 }
 215
 216 /* Create RTL for the local static variable DECL.  */
 217
 218 void
 219 make_rtl_for_local_static (decl)
 220      tree decl;
 221 {
 222   const char *asmspec = NULL;
 223
 224   /* If we inlined this variable, we could see it's declaration
 225      again.  */
 226   if (TREE_ASM_WRITTEN (decl))
 227     return;
 228
 229   /* If the DECL_ASSEMBLER_NAME is not the same as the DECL_NAME, then
 230      either we already created RTL for this DECL (and since it was a
 231      local variable, its DECL_ASSEMBLER_NAME got hacked up to prevent
 232      clashes with other local statics with the same name by a previous
 233      call to make_decl_rtl), or the user explicitly requested a
 234      particular assembly name for this variable, using the GNU
 235      extension for this purpose:
 236
 237        int i asm ("j");
 238
 239      There's no way to know which case we're in, here.  But, it turns
 240      out we're safe.  If there's already RTL, then
 241      rest_of_decl_compilation ignores the ASMSPEC parameter, so we
 242      may as well not pass it in.  If there isn't RTL, then we didn't
 243      already create RTL, which means that the modification to
 244      DECL_ASSEMBLER_NAME came only via the explicit extension.  */
 245   if (DECL_ASSEMBLER_NAME (decl) != DECL_NAME (decl)
 246       && !DECL_RTL (decl))
 247     asmspec = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl));
 248
 249   rest_of_decl_compilation (decl, asmspec, /*top_level=*/0, /*at_end=*/0);
 250 }
 251
 252 /* Let the back-end know about DECL.  */
 253
 254 void
 255 emit_local_var (decl)
 256      tree decl;
 257 {
 258   /* Create RTL for this variable.  */
 259   if (!DECL_RTL_SET_P (decl))
 260     {
 261       if (DECL_C_HARD_REGISTER (decl))
 262         /* The user specified an assembler name for this variable.
 263            Set that up now.  */
 264         rest_of_decl_compilation
 265           (decl, IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (decl)),
 266            /*top_level=*/0, /*at_end=*/0);
 267       else
 268         expand_decl (decl);
 269     }
 270
 271   /* Actually do the initialization.  */
 272   if (stmts_are_full_exprs_p ())
 273     expand_start_target_temps ();
 274
 275   expand_decl_init (decl);
 276
 277   if (stmts_are_full_exprs_p ())
 278     expand_end_target_temps ();
 279 }
 280
 281 /* Helper for generating the RTL at the beginning of a scope. */
 282
 283 void
 284 genrtl_do_pushlevel ()
 285 {
 286   emit_line_note (input_filename, lineno);
 287   clear_last_expr ();
 288 }
 289
 290 /* Generate the RTL for DESTINATION, which is a GOTO_STMT. */
 291
 292 void
 293 genrtl_goto_stmt (destination)
 294      tree destination;
 295 {
 296   if (TREE_CODE (destination) == IDENTIFIER_NODE)
 297     abort ();
 298
 299   /* We warn about unused labels with -Wunused.  That means we have to
 300      mark the used labels as used.  */
 301   if (TREE_CODE (destination) == LABEL_DECL)
 302     TREE_USED (destination) = 1;
 303
 304   emit_line_note (input_filename, lineno);
 305
 306   if (TREE_CODE (destination) == LABEL_DECL)
 307     {
 308       label_rtx (destination);
 309       expand_goto (destination);
 310     }
 311   else
 312     expand_computed_goto (destination);
 313 }
 314
 315 /* Generate the RTL for EXPR, which is an EXPR_STMT. */
 316
 317 void
 318 genrtl_expr_stmt (expr)
 319      tree expr;
 320 {
 321   if (expr != NULL_TREE)
 322     {
 323       emit_line_note (input_filename, lineno);
 324
 325       if (stmts_are_full_exprs_p ())
 326         expand_start_target_temps ();
 327
 328       if (expr != error_mark_node)
 329         expand_expr_stmt (expr);
 330
 331       if (stmts_are_full_exprs_p ())
 332         expand_end_target_temps ();
 333     }
 334 }
 335
 336 /* Generate the RTL for T, which is a DECL_STMT. */
 337
 338 void
 339 genrtl_decl_stmt (t)
 340      tree t;
 341 {
 342   tree decl;
 343   emit_line_note (input_filename, lineno);
 344   decl = DECL_STMT_DECL (t);
 345   /* If this is a declaration for an automatic local
 346      variable, initialize it.  Note that we might also see a
 347      declaration for a namespace-scope object (declared with
 348      `extern').  We don't have to handle the initialization
 349      of those objects here; they can only be declarations,
 350      rather than definitions.  */
 351   if (TREE_CODE (decl) == VAR_DECL
 352       && !TREE_STATIC (decl)
 353       && !DECL_EXTERNAL (decl))
 354     {
 355       /* Let the back-end know about this variable.  */
 356       if (!anon_aggr_type_p (TREE_TYPE (decl)))
 357         emit_local_var (decl);
 358       else
 359         expand_anon_union_decl (decl, NULL_TREE,
 360                                 DECL_ANON_UNION_ELEMS (decl));
 361     }
 362   else if (TREE_CODE (decl) == VAR_DECL && TREE_STATIC (decl))
 363     make_rtl_for_local_static (decl);
 364   else if (TREE_CODE (decl) == LABEL_DECL
 365            && C_DECLARED_LABEL_FLAG (decl))
 366     declare_nonlocal_label (decl);
 367   else if (lang_expand_decl_stmt)
 368     (*lang_expand_decl_stmt) (t);
 369 }
 370
 371 /* Generate the RTL for T, which is an IF_STMT. */
 372
 373 void
 374 genrtl_if_stmt (t)
 375      tree t;
 376 {
 377   tree cond;
 378   genrtl_do_pushlevel ();
 379   cond = expand_cond (IF_COND (t));
 380   emit_line_note (input_filename, lineno);
 381   expand_start_cond (cond, 0);
 382   if (THEN_CLAUSE (t))
 383     expand_stmt (THEN_CLAUSE (t));
 384   if (ELSE_CLAUSE (t))
 385     {
 386       expand_start_else ();
 387       expand_stmt (ELSE_CLAUSE (t));
 388     }
 389   expand_end_cond ();
 390 }
 391
 392 /* Generate the RTL for T, which is a WHILE_STMT. */
 393
 394 void
 395 genrtl_while_stmt (t)
 396      tree t;
 397 {
 398   tree cond;
 399   emit_nop ();
 400   emit_line_note (input_filename, lineno);
 401   expand_start_loop (1);
 402   genrtl_do_pushlevel ();
 403
 404   cond = expand_cond (WHILE_COND (t));
 405   emit_line_note (input_filename, lineno);
 406   expand_exit_loop_if_false (0, cond);
 407   genrtl_do_pushlevel ();
 408
 409   expand_stmt (WHILE_BODY (t));
 410
 411   expand_end_loop ();
 412 }
 413
 414 /* Generate the RTL for T, which is a DO_STMT. */
 415
 416 void
 417 genrtl_do_stmt (t)
 418      tree t;
 419 {
 420   tree cond = DO_COND (t);
 421
 422   /* Recognize the common special-case of do { ... } while (0) and do
 423      not emit the loop widgetry in this case.  In particular this
 424      avoids cluttering the rtl with dummy loop notes, which can affect
 425      alignment of adjacent labels.  */
 426   if (integer_zerop (cond))
 427     {
 428       expand_start_null_loop ();
 429       expand_stmt (DO_BODY (t));
 430       expand_end_null_loop ();
 431     }
 432   else
 433     {
 434       emit_nop ();
 435       emit_line_note (input_filename, lineno);
 436       expand_start_loop_continue_elsewhere (1);
 437
 438       expand_stmt (DO_BODY (t));
 439
 440       expand_loop_continue_here ();
 441       cond = expand_cond (cond);
 442       emit_line_note (input_filename, lineno);
 443       expand_exit_loop_if_false (0, cond);
 444       expand_end_loop ();
 445     }
 446 }
 447
 448 /* Build the node for a return statement and return it. */
 449
 450 tree
 451 build_return_stmt (expr)
 452      tree expr;
 453 {
 454   return (build_stmt (RETURN_STMT, expr));
 455 }
 456
 457 /* Generate the RTL for STMT, which is a RETURN_STMT. */
 458
 459 void
 460 genrtl_return_stmt (stmt)
 461      tree stmt;
 462 {
 463   tree expr = RETURN_EXPR (stmt);
 464
 465   emit_line_note (input_filename, lineno);
 466   if (!expr)
 467     expand_null_return ();
 468   else
 469     {
 470       expand_start_target_temps ();
 471       expand_return (expr);
 472       expand_end_target_temps ();
 473     }
 474 }
 475
 476 /* Generate the RTL for T, which is a FOR_STMT. */
 477
 478 void
 479 genrtl_for_stmt (t)
 480      tree t;
 481 {
 482   tree cond;
 483   const char *saved_filename;
 484   int saved_lineno;
 485
 486   if (NEW_FOR_SCOPE_P (t))
 487     genrtl_do_pushlevel ();
 488
 489   expand_stmt (FOR_INIT_STMT (t));
 490
 491   /* Expand the initialization.  */
 492   emit_nop ();
 493   emit_line_note (input_filename, lineno);
 494   expand_start_loop_continue_elsewhere (1);
 495   genrtl_do_pushlevel ();
 496   cond = expand_cond (FOR_COND (t));
 497
 498   /* Save the filename and line number so that we expand the FOR_EXPR
 499      we can reset them back to the saved values.  */
 500   saved_filename = input_filename;
 501   saved_lineno = lineno;
 502
 503   /* Expand the condition.  */
 504   emit_line_note (input_filename, lineno);
 505   if (cond)
 506     expand_exit_loop_if_false (0, cond);
 507
 508   /* Expand the body.  */
 509   genrtl_do_pushlevel ();
 510   expand_stmt (FOR_BODY (t));
 511
 512   /* Expand the increment expression.  */
 513   input_filename = saved_filename;
 514   lineno = saved_lineno;
 515   emit_line_note (input_filename, lineno);
 516   expand_loop_continue_here ();
 517   if (FOR_EXPR (t))
 518     genrtl_expr_stmt (FOR_EXPR (t));
 519   expand_end_loop ();
 520 }
 521
 522 /* Build a break statement node and return it. */
 523
 524 tree
 525 build_break_stmt ()
 526 {
 527   return (build_stmt (BREAK_STMT));
 528 }
 529
 530 /* Generate the RTL for a BREAK_STMT. */
 531
 532 void
 533 genrtl_break_stmt ()
 534 {
 535   emit_line_note (input_filename, lineno);
 536   if ( ! expand_exit_something ())
 537     error ("break statement not within loop or switch");
 538 }
 539
 540 /* Build a continue statement node and return it. */
 541
 542 tree
 543 build_continue_stmt ()
 544 {
 545   return (build_stmt (CONTINUE_STMT));
 546 }
 547
 548 /* Generate the RTL for a CONTINUE_STMT. */
 549
 550 void
 551 genrtl_continue_stmt ()
 552 {
 553   emit_line_note (input_filename, lineno);
 554   if (! expand_continue_loop (0))
 555     error ("continue statement not within a loop");
 556 }
 557
 558 /* Generate the RTL for T, which is a SCOPE_STMT. */
 559
 560 void
 561 genrtl_scope_stmt (t)
 562      tree t;
 563 {
 564   if (!SCOPE_NO_CLEANUPS_P (t))
 565     {
 566       if (SCOPE_BEGIN_P (t))
 567         expand_start_bindings_and_block (2 * SCOPE_NULLIFIED_P (t),
 568                                          SCOPE_STMT_BLOCK (t));
 569       else if (SCOPE_END_P (t))
 570         expand_end_bindings (NULL_TREE, !SCOPE_NULLIFIED_P (t), 0);
 571     }
 572   else if (!SCOPE_NULLIFIED_P (t))
 573     {
 574       rtx note = emit_note (NULL,
 575                             (SCOPE_BEGIN_P (t)
 576                              ? NOTE_INSN_BLOCK_BEG
 577                              : NOTE_INSN_BLOCK_END));
 578       NOTE_BLOCK (note) = SCOPE_STMT_BLOCK (t);
 579     }
 580 }
 581
 582 /* Generate the RTL for T, which is a SWITCH_STMT. */
 583
 584 void
 585 genrtl_switch_stmt (t)
 586      tree t;
 587 {
 588   tree cond;
 589   genrtl_do_pushlevel ();
 590
 591   cond = expand_cond (SWITCH_COND (t));
 592   if (cond == error_mark_node)
 593     /* The code is in error, but we don't want expand_end_case to
 594        crash. */
 595     cond = boolean_false_node;
 596
 597   emit_line_note (input_filename, lineno);
 598   expand_start_case (1, cond, TREE_TYPE (cond), "switch statement");
 599   expand_stmt (SWITCH_BODY (t));
 600   expand_end_case (cond);
 601 }
 602
 603 /* Create a CASE_LABEL tree node and return it. */
 604
 605 tree
 606 build_case_label (low_value, high_value, label_decl)
 607      tree low_value;
 608      tree high_value;
 609      tree label_decl;
 610 {
 611   return build_stmt (CASE_LABEL, low_value, high_value, label_decl);
 612 }
 613
 614
 615 /* Generate the RTL for a CASE_LABEL. */
 616
 617 void
 618 genrtl_case_label (case_label)
 619      tree case_label;
 620 {
 621   tree duplicate;
 622   tree cleanup;
 623
 624   cleanup = last_cleanup_this_contour ();
 625   if (cleanup)
 626     {
 627       static int explained = 0;
 628       warning_with_decl (TREE_PURPOSE (cleanup),
 629                          "destructor needed for `%#D'");
 630       warning ("where case label appears here");
 631       if (!explained)
 632         {
 633           warning ("(enclose actions of previous case statements requiring destructors in their own scope.)");
 634           explained = 1;
 635         }
 636     }
 637
 638   add_case_node (CASE_LOW (case_label), CASE_HIGH (case_label),
 639                  CASE_LABEL_DECL (case_label), &duplicate);
 640 }
 641
 642 /* Generate the RTL for T, which is a COMPOUND_STMT. */
 643
 644 void
 645 genrtl_compound_stmt (t)
 646     tree t;
 647 {
 648   expand_stmt (COMPOUND_BODY (t));
 649 }
 650
 651 /* Generate the RTL for an ASM_STMT. */
 652
 653 void
 654 genrtl_asm_stmt (cv_qualifier, string, output_operands,
 655                  input_operands, clobbers, asm_input_p)
 656      tree cv_qualifier;
 657      tree string;
 658      tree output_operands;
 659      tree input_operands;
 660      tree clobbers;
 661      int asm_input_p;
 662 {
 663   if (cv_qualifier != NULL_TREE
 664       && cv_qualifier != ridpointers[(int) RID_VOLATILE])
 665     {
 666       warning ("%s qualifier ignored on asm",
 667                IDENTIFIER_POINTER (cv_qualifier));
 668       cv_qualifier = NULL_TREE;
 669     }
 670
 671   emit_line_note (input_filename, lineno);
 672   if (asm_input_p)
 673     expand_asm (string);
 674   else
 675     c_expand_asm_operands (string, output_operands, input_operands,
 676                            clobbers, cv_qualifier != NULL_TREE,
 677                            input_filename, lineno);
 678 }
 679
 680 /* Generate the RTL for a DECL_CLEANUP. */
 681
 682 void
 683 genrtl_decl_cleanup (decl, cleanup)
 684      tree decl;
 685      tree cleanup;
 686 {
 687   if (!decl || (DECL_SIZE (decl) && TREE_TYPE (decl) != error_mark_node))
 688     expand_decl_cleanup (decl, cleanup);
 689 }
 690
 691 /* We're about to expand T, a statement.  Set up appropriate context
 692    for the substitution.  */
 693
 694 void
 695 prep_stmt (t)
 696      tree t;
 697 {
 698   if (!STMT_LINENO_FOR_FN_P (t))
 699     lineno = STMT_LINENO (t);
 700   current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
 701 }
 702
 703 /* Generate the RTL for the statement T, its substatements, and any
 704    other statements at its nesting level. */
 705
 706 void
 707 expand_stmt (t)
 708      tree t;
 709 {
 710   while (t && t != error_mark_node)
 711     {
 712       int saved_stmts_are_full_exprs_p;
 713
 714       /* Set up context appropriately for handling this statement.  */
 715       saved_stmts_are_full_exprs_p = stmts_are_full_exprs_p ();
 716       prep_stmt (t);
 717
 718       switch (TREE_CODE (t))
 719         {
 720         case RETURN_STMT:
 721           genrtl_return_stmt (t);
 722           break;
 723
 724         case EXPR_STMT:
 725           genrtl_expr_stmt (EXPR_STMT_EXPR (t));
 726           break;
 727
 728         case DECL_STMT:
 729           genrtl_decl_stmt (t);
 730           break;
 731
 732         case FOR_STMT:
 733           genrtl_for_stmt (t);
 734           break;
 735
 736         case WHILE_STMT:
 737           genrtl_while_stmt (t);
 738           break;
 739
 740         case DO_STMT:
 741           genrtl_do_stmt (t);
 742           break;
 743
 744         case IF_STMT:
 745           genrtl_if_stmt (t);
 746           break;
 747
 748         case COMPOUND_STMT:
 749           genrtl_compound_stmt (t);
 750           break;
 751
 752         case BREAK_STMT:
 753           genrtl_break_stmt ();
 754           break;
 755
 756         case CONTINUE_STMT:
 757           genrtl_continue_stmt ();
 758           break;
 759
 760         case SWITCH_STMT:
 761           genrtl_switch_stmt (t);
 762           break;
 763
 764         case CASE_LABEL:
 765           genrtl_case_label (t);
 766           break;
 767
 768         case LABEL_STMT:
 769           expand_label (LABEL_STMT_LABEL (t));
 770           break;
 771
 772         case GOTO_STMT:
 773           genrtl_goto_stmt (GOTO_DESTINATION (t));
 774           break;
 775
 776         case ASM_STMT:
 777           genrtl_asm_stmt (ASM_CV_QUAL (t), ASM_STRING (t),
 778                            ASM_OUTPUTS (t), ASM_INPUTS (t),
 779                            ASM_CLOBBERS (t), ASM_INPUT_P (t));
 780           break;
 781
 782         case SCOPE_STMT:
 783           genrtl_scope_stmt (t);
 784           break;
 785
 786         default:
 787           if (lang_expand_stmt)
 788             (*lang_expand_stmt) (t);
 789           else
 790             abort ();
 791           break;
 792         }
 793
 794       /* Restore saved state.  */
 795       current_stmt_tree ()->stmts_are_full_exprs_p
 796         = saved_stmts_are_full_exprs_p;
 797
 798       /* Go on to the next statement in this scope.  */
 799       t = TREE_CHAIN (t);
 800     }
 801 }
 802