nsz Git - cparser/blob - ast.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include "ast_t.h"
  23 #include "symbol_t.h"
  24 #include "type_t.h"
  25 #include "parser.h"
  26 #include "lang_features.h"
  27 #include "entity_t.h"
  28 #include "printer.h"
  29 #include "types.h"
  30
  31 #include <assert.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <ctype.h>
  35
  36 #if defined(__INTEL_COMPILER)
  37 #include <mathimf.h>
  38 #elif defined(__CYGWIN__)
  39 #include "win32/cygwin_math_ext.h"
  40 #else
  41 #include <math.h>
  42 #endif
  43
  44 #include "adt/error.h"
  45 #include "adt/util.h"
  46
  47 struct obstack ast_obstack;
  48
  49 static int indent;
  50
  51 bool print_implicit_casts = false;
  52 bool print_parenthesis = false;
  53
  54 static void print_statement(const statement_t *statement);
  55 static void print_expression_prec(const expression_t *expression, unsigned prec);
  56
  57 void change_indent(int delta)
  58 {
  59         indent += delta;
  60         assert(indent >= 0);
  61 }
  62
  63 void print_indent(void)
  64 {
  65         for (int i = 0; i < indent; ++i)
  66                 print_string("\t");
  67 }
  68
  69 static void print_stringrep(const string_t *string)
  70 {
  71         for (size_t i = 0; i < string->size; ++i) {
  72                 print_char(string->begin[i]);
  73         }
  74 }
  75
  76 /**
  77  * Returns 1 if a given precedence level has right-to-left
  78  * associativity, else 0.
  79  *
  80  * @param precedence   the operator precedence
  81  */
  82 static int right_to_left(unsigned precedence)
  83 {
  84         switch (precedence) {
  85         case PREC_ASSIGNMENT:
  86         case PREC_CONDITIONAL:
  87         case PREC_UNARY:
  88                 return 1;
  89
  90         default:
  91                 return 0;
  92         }
  93 }
  94
  95 /**
  96  * Return the precedence of an expression given by its kind.
  97  *
  98  * @param kind   the expression kind
  99  */
 100 static unsigned get_expression_precedence(expression_kind_t kind)
 101 {
 102         static const unsigned prec[] = {
 103                 [EXPR_INVALID]                           = PREC_PRIMARY,
 104                 [EXPR_REFERENCE]                         = PREC_PRIMARY,
 105                 [EXPR_REFERENCE_ENUM_VALUE]              = PREC_PRIMARY,
 106                 [EXPR_LITERAL_INTEGER]                   = PREC_PRIMARY,
 107                 [EXPR_LITERAL_INTEGER_OCTAL]             = PREC_PRIMARY,
 108                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]       = PREC_PRIMARY,
 109                 [EXPR_LITERAL_FLOATINGPOINT]             = PREC_PRIMARY,
 110                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = PREC_PRIMARY,
 111                 [EXPR_LITERAL_CHARACTER]                 = PREC_PRIMARY,
 112                 [EXPR_LITERAL_WIDE_CHARACTER]            = PREC_PRIMARY,
 113                 [EXPR_LITERAL_MS_NOOP]                   = PREC_PRIMARY,
 114                 [EXPR_STRING_LITERAL]                    = PREC_PRIMARY,
 115                 [EXPR_WIDE_STRING_LITERAL]               = PREC_PRIMARY,
 116                 [EXPR_COMPOUND_LITERAL]                  = PREC_UNARY,
 117                 [EXPR_CALL]                              = PREC_POSTFIX,
 118                 [EXPR_CONDITIONAL]                       = PREC_CONDITIONAL,
 119                 [EXPR_SELECT]                            = PREC_POSTFIX,
 120                 [EXPR_ARRAY_ACCESS]                      = PREC_POSTFIX,
 121                 [EXPR_SIZEOF]                            = PREC_UNARY,
 122                 [EXPR_CLASSIFY_TYPE]                     = PREC_UNARY,
 123                 [EXPR_ALIGNOF]                           = PREC_UNARY,
 124
 125                 [EXPR_FUNCNAME]                          = PREC_PRIMARY,
 126                 [EXPR_BUILTIN_CONSTANT_P]                = PREC_PRIMARY,
 127                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P]        = PREC_PRIMARY,
 128                 [EXPR_OFFSETOF]                          = PREC_PRIMARY,
 129                 [EXPR_VA_START]                          = PREC_PRIMARY,
 130                 [EXPR_VA_ARG]                            = PREC_PRIMARY,
 131                 [EXPR_VA_COPY]                           = PREC_PRIMARY,
 132                 [EXPR_STATEMENT]                         = PREC_PRIMARY,
 133                 [EXPR_LABEL_ADDRESS]                     = PREC_PRIMARY,
 134
 135                 [EXPR_UNARY_NEGATE]                      = PREC_UNARY,
 136                 [EXPR_UNARY_PLUS]                        = PREC_UNARY,
 137                 [EXPR_UNARY_BITWISE_NEGATE]              = PREC_UNARY,
 138                 [EXPR_UNARY_NOT]                         = PREC_UNARY,
 139                 [EXPR_UNARY_DEREFERENCE]                 = PREC_UNARY,
 140                 [EXPR_UNARY_TAKE_ADDRESS]                = PREC_UNARY,
 141                 [EXPR_UNARY_POSTFIX_INCREMENT]           = PREC_POSTFIX,
 142                 [EXPR_UNARY_POSTFIX_DECREMENT]           = PREC_POSTFIX,
 143                 [EXPR_UNARY_PREFIX_INCREMENT]            = PREC_UNARY,
 144                 [EXPR_UNARY_PREFIX_DECREMENT]            = PREC_UNARY,
 145                 [EXPR_UNARY_CAST]                        = PREC_UNARY,
 146                 [EXPR_UNARY_ASSUME]                      = PREC_PRIMARY,
 147                 [EXPR_UNARY_DELETE]                      = PREC_UNARY,
 148                 [EXPR_UNARY_DELETE_ARRAY]                = PREC_UNARY,
 149                 [EXPR_UNARY_THROW]                       = PREC_ASSIGNMENT,
 150
 151                 [EXPR_BINARY_ADD]                        = PREC_ADDITIVE,
 152                 [EXPR_BINARY_SUB]                        = PREC_ADDITIVE,
 153                 [EXPR_BINARY_MUL]                        = PREC_MULTIPLICATIVE,
 154                 [EXPR_BINARY_DIV]                        = PREC_MULTIPLICATIVE,
 155                 [EXPR_BINARY_MOD]                        = PREC_MULTIPLICATIVE,
 156                 [EXPR_BINARY_EQUAL]                      = PREC_EQUALITY,
 157                 [EXPR_BINARY_NOTEQUAL]                   = PREC_EQUALITY,
 158                 [EXPR_BINARY_LESS]                       = PREC_RELATIONAL,
 159                 [EXPR_BINARY_LESSEQUAL]                  = PREC_RELATIONAL,
 160                 [EXPR_BINARY_GREATER]                    = PREC_RELATIONAL,
 161                 [EXPR_BINARY_GREATEREQUAL]               = PREC_RELATIONAL,
 162                 [EXPR_BINARY_BITWISE_AND]                = PREC_AND,
 163                 [EXPR_BINARY_BITWISE_OR]                 = PREC_OR,
 164                 [EXPR_BINARY_BITWISE_XOR]                = PREC_XOR,
 165                 [EXPR_BINARY_LOGICAL_AND]                = PREC_LOGICAL_AND,
 166                 [EXPR_BINARY_LOGICAL_OR]                 = PREC_LOGICAL_OR,
 167                 [EXPR_BINARY_SHIFTLEFT]                  = PREC_SHIFT,
 168                 [EXPR_BINARY_SHIFTRIGHT]                 = PREC_SHIFT,
 169                 [EXPR_BINARY_ASSIGN]                     = PREC_ASSIGNMENT,
 170                 [EXPR_BINARY_MUL_ASSIGN]                 = PREC_ASSIGNMENT,
 171                 [EXPR_BINARY_DIV_ASSIGN]                 = PREC_ASSIGNMENT,
 172                 [EXPR_BINARY_MOD_ASSIGN]                 = PREC_ASSIGNMENT,
 173                 [EXPR_BINARY_ADD_ASSIGN]                 = PREC_ASSIGNMENT,
 174                 [EXPR_BINARY_SUB_ASSIGN]                 = PREC_ASSIGNMENT,
 175                 [EXPR_BINARY_SHIFTLEFT_ASSIGN]           = PREC_ASSIGNMENT,
 176                 [EXPR_BINARY_SHIFTRIGHT_ASSIGN]          = PREC_ASSIGNMENT,
 177                 [EXPR_BINARY_BITWISE_AND_ASSIGN]         = PREC_ASSIGNMENT,
 178                 [EXPR_BINARY_BITWISE_XOR_ASSIGN]         = PREC_ASSIGNMENT,
 179                 [EXPR_BINARY_BITWISE_OR_ASSIGN]          = PREC_ASSIGNMENT,
 180                 [EXPR_BINARY_COMMA]                      = PREC_EXPRESSION,
 181
 182                 [EXPR_BINARY_ISGREATER]                  = PREC_PRIMARY,
 183                 [EXPR_BINARY_ISGREATEREQUAL]             = PREC_PRIMARY,
 184                 [EXPR_BINARY_ISLESS]                     = PREC_PRIMARY,
 185                 [EXPR_BINARY_ISLESSEQUAL]                = PREC_PRIMARY,
 186                 [EXPR_BINARY_ISLESSGREATER]              = PREC_PRIMARY,
 187                 [EXPR_BINARY_ISUNORDERED]                = PREC_PRIMARY
 188         };
 189         assert((size_t)kind < lengthof(prec));
 190         unsigned res = prec[kind];
 191
 192         assert(res != PREC_BOTTOM);
 193         return res;
 194 }
 195
 196 /**
 197  * Print a quoted string constant.
 198  *
 199  * @param string  the string constant
 200  * @param border  the border char
 201  * @param skip    number of chars to skip at the end
 202  */
 203 static void print_quoted_string(const string_t *const string, char border,
 204                                 int skip)
 205 {
 206         print_char(border);
 207         const char *end = string->begin + string->size - skip;
 208         for (const char *c = string->begin; c != end; ++c) {
 209                 const char tc = *c;
 210                 if (tc == border) {
 211                         print_string("\\");
 212                 }
 213                 switch (tc) {
 214                 case '\\': print_string("\\\\"); break;
 215                 case '\a': print_string("\\a"); break;
 216                 case '\b': print_string("\\b"); break;
 217                 case '\f': print_string("\\f"); break;
 218                 case '\n': print_string("\\n"); break;
 219                 case '\r': print_string("\\r"); break;
 220                 case '\t': print_string("\\t"); break;
 221                 case '\v': print_string("\\v"); break;
 222                 case '\?': print_string("\\?"); break;
 223                 case 27:
 224                         if (c_mode & _GNUC) {
 225                                 print_string("\\e"); break;
 226                         }
 227                         /* FALLTHROUGH */
 228                 default:
 229                         if ((unsigned)tc < 0x80 && !isprint(tc)) {
 230                                 print_format("\\%03o", (unsigned)tc);
 231                         } else {
 232                                 print_char(tc);
 233                         }
 234                         break;
 235                 }
 236         }
 237         print_char(border);
 238 }
 239
 240 static void print_string_literal(const string_literal_expression_t *literal)
 241 {
 242         if (literal->base.kind == EXPR_WIDE_STRING_LITERAL) {
 243                 print_char('L');
 244         }
 245         print_quoted_string(&literal->value, '"', 1);
 246 }
 247
 248 static void print_literal(const literal_expression_t *literal)
 249 {
 250         switch (literal->base.kind) {
 251         case EXPR_LITERAL_MS_NOOP:
 252                 print_string("__noop");
 253                 return;
 254         case EXPR_LITERAL_INTEGER_HEXADECIMAL:
 255         case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL:
 256                 print_string("0x");
 257                 /* FALLTHROUGH */
 258         case EXPR_LITERAL_BOOLEAN:
 259         case EXPR_LITERAL_INTEGER:
 260         case EXPR_LITERAL_INTEGER_OCTAL:
 261         case EXPR_LITERAL_FLOATINGPOINT:
 262                 print_stringrep(&literal->value);
 263                 if (literal->suffix.size > 0)
 264                         print_stringrep(&literal->suffix);
 265                 return;
 266         case EXPR_LITERAL_WIDE_CHARACTER:
 267                 print_char('L');
 268                 /* FALLTHROUGH */
 269         case EXPR_LITERAL_CHARACTER:
 270                 print_quoted_string(&literal->value, '\'', 0);
 271                 return;
 272         default:
 273                 break;
 274         }
 275         print_string("INVALID LITERAL KIND");
 276 }
 277
 278 /**
 279  * Prints a predefined symbol.
 280  */
 281 static void print_funcname(const funcname_expression_t *funcname)
 282 {
 283         const char *s = "";
 284         switch (funcname->kind) {
 285         case FUNCNAME_FUNCTION:        s = (c_mode & _C99) ? "__func__" : "__FUNCTION__"; break;
 286         case FUNCNAME_PRETTY_FUNCTION: s = "__PRETTY_FUNCTION__"; break;
 287         case FUNCNAME_FUNCSIG:         s = "__FUNCSIG__"; break;
 288         case FUNCNAME_FUNCDNAME:       s = "__FUNCDNAME__"; break;
 289         }
 290         print_string(s);
 291 }
 292
 293 static void print_compound_literal(
 294                 const compound_literal_expression_t *expression)
 295 {
 296         print_string("(");
 297         print_type(expression->type);
 298         print_string(")");
 299         print_initializer(expression->initializer);
 300 }
 301
 302 static void print_assignment_expression(const expression_t *const expr)
 303 {
 304         print_expression_prec(expr, PREC_ASSIGNMENT);
 305 }
 306
 307 /**
 308  * Prints a call expression.
 309  *
 310  * @param call  the call expression
 311  */
 312 static void print_call_expression(const call_expression_t *call)
 313 {
 314         print_expression_prec(call->function, PREC_POSTFIX);
 315         print_string("(");
 316         call_argument_t *argument = call->arguments;
 317         int              first    = 1;
 318         while (argument != NULL) {
 319                 if (!first) {
 320                         print_string(", ");
 321                 } else {
 322                         first = 0;
 323                 }
 324                 print_assignment_expression(argument->expression);
 325
 326                 argument = argument->next;
 327         }
 328         print_string(")");
 329 }
 330
 331 /**
 332  * Prints a binary expression.
 333  *
 334  * @param binexpr   the binary expression
 335  */
 336 static void print_binary_expression(const binary_expression_t *binexpr)
 337 {
 338         unsigned prec = get_expression_precedence(binexpr->base.kind);
 339         int      r2l  = right_to_left(prec);
 340
 341         print_expression_prec(binexpr->left, prec + r2l);
 342         char const* op;
 343         switch (binexpr->base.kind) {
 344         case EXPR_BINARY_COMMA:              op = ", ";    break;
 345         case EXPR_BINARY_ASSIGN:             op = " = ";   break;
 346         case EXPR_BINARY_ADD:                op = " + ";   break;
 347         case EXPR_BINARY_SUB:                op = " - ";   break;
 348         case EXPR_BINARY_MUL:                op = " * ";   break;
 349         case EXPR_BINARY_MOD:                op = " % ";   break;
 350         case EXPR_BINARY_DIV:                op = " / ";   break;
 351         case EXPR_BINARY_BITWISE_OR:         op = " | ";   break;
 352         case EXPR_BINARY_BITWISE_AND:        op = " & ";   break;
 353         case EXPR_BINARY_BITWISE_XOR:        op = " ^ ";   break;
 354         case EXPR_BINARY_LOGICAL_OR:         op = " || ";  break;
 355         case EXPR_BINARY_LOGICAL_AND:        op = " && ";  break;
 356         case EXPR_BINARY_NOTEQUAL:           op = " != ";  break;
 357         case EXPR_BINARY_EQUAL:              op = " == ";  break;
 358         case EXPR_BINARY_LESS:               op = " < ";   break;
 359         case EXPR_BINARY_LESSEQUAL:          op = " <= ";  break;
 360         case EXPR_BINARY_GREATER:            op = " > ";   break;
 361         case EXPR_BINARY_GREATEREQUAL:       op = " >= ";  break;
 362         case EXPR_BINARY_SHIFTLEFT:          op = " << ";  break;
 363         case EXPR_BINARY_SHIFTRIGHT:         op = " >> ";  break;
 364
 365         case EXPR_BINARY_ADD_ASSIGN:         op = " += ";  break;
 366         case EXPR_BINARY_SUB_ASSIGN:         op = " -= ";  break;
 367         case EXPR_BINARY_MUL_ASSIGN:         op = " *= ";  break;
 368         case EXPR_BINARY_MOD_ASSIGN:         op = " %= ";  break;
 369         case EXPR_BINARY_DIV_ASSIGN:         op = " /= ";  break;
 370         case EXPR_BINARY_BITWISE_OR_ASSIGN:  op = " |= ";  break;
 371         case EXPR_BINARY_BITWISE_AND_ASSIGN: op = " &= ";  break;
 372         case EXPR_BINARY_BITWISE_XOR_ASSIGN: op = " ^= ";  break;
 373         case EXPR_BINARY_SHIFTLEFT_ASSIGN:   op = " <<= "; break;
 374         case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  op = " >>= "; break;
 375         default: panic("invalid binexpression found");
 376         }
 377         print_string(op);
 378         print_expression_prec(binexpr->right, prec + 1 - r2l);
 379 }
 380
 381 /**
 382  * Prints an unary expression.
 383  *
 384  * @param unexpr   the unary expression
 385  */
 386 static void print_unary_expression(const unary_expression_t *unexpr)
 387 {
 388         unsigned prec = get_expression_precedence(unexpr->base.kind);
 389         switch (unexpr->base.kind) {
 390         case EXPR_UNARY_NEGATE:           print_string("-"); break;
 391         case EXPR_UNARY_PLUS:             print_string("+"); break;
 392         case EXPR_UNARY_NOT:              print_string("!"); break;
 393         case EXPR_UNARY_BITWISE_NEGATE:   print_string("~"); break;
 394         case EXPR_UNARY_PREFIX_INCREMENT: print_string("++"); break;
 395         case EXPR_UNARY_PREFIX_DECREMENT: print_string("--"); break;
 396         case EXPR_UNARY_DEREFERENCE:      print_string("*"); break;
 397         case EXPR_UNARY_TAKE_ADDRESS:     print_string("&"); break;
 398         case EXPR_UNARY_DELETE:           print_string("delete "); break;
 399         case EXPR_UNARY_DELETE_ARRAY:     print_string("delete [] "); break;
 400
 401         case EXPR_UNARY_POSTFIX_INCREMENT:
 402                 print_expression_prec(unexpr->value, prec);
 403                 print_string("++");
 404                 return;
 405         case EXPR_UNARY_POSTFIX_DECREMENT:
 406                 print_expression_prec(unexpr->value, prec);
 407                 print_string("--");
 408                 return;
 409         case EXPR_UNARY_CAST:
 410                 print_string("(");
 411                 print_type(unexpr->base.type);
 412                 print_string(")");
 413                 break;
 414         case EXPR_UNARY_ASSUME:
 415                 print_string("__assume(");
 416                 print_assignment_expression(unexpr->value);
 417                 print_string(")");
 418                 return;
 419
 420         case EXPR_UNARY_THROW:
 421                 if (unexpr->value == NULL) {
 422                         print_string("throw");
 423                         return;
 424                 }
 425                 print_string("throw ");
 426                 break;
 427
 428         default:
 429                 panic("invalid unary expression found");
 430         }
 431         print_expression_prec(unexpr->value, prec);
 432 }
 433
 434 /**
 435  * Prints a reference expression.
 436  *
 437  * @param ref   the reference expression
 438  */
 439 static void print_reference_expression(const reference_expression_t *ref)
 440 {
 441         print_string(ref->entity->base.symbol->string);
 442 }
 443
 444 /**
 445  * Prints a label address expression.
 446  *
 447  * @param ref   the reference expression
 448  */
 449 static void print_label_address_expression(const label_address_expression_t *le)
 450 {
 451         print_format("&&%s", le->label->base.symbol->string);
 452 }
 453
 454 /**
 455  * Prints an array expression.
 456  *
 457  * @param expression   the array expression
 458  */
 459 static void print_array_expression(const array_access_expression_t *expression)
 460 {
 461         if (!expression->flipped) {
 462                 print_expression_prec(expression->array_ref, PREC_POSTFIX);
 463                 print_string("[");
 464                 print_expression(expression->index);
 465                 print_string("]");
 466         } else {
 467                 print_expression_prec(expression->index, PREC_POSTFIX);
 468                 print_string("[");
 469                 print_expression(expression->array_ref);
 470                 print_string("]");
 471         }
 472 }
 473
 474 /**
 475  * Prints a typeproperty expression (sizeof or __alignof__).
 476  *
 477  * @param expression   the type property expression
 478  */
 479 static void print_typeprop_expression(const typeprop_expression_t *expression)
 480 {
 481         if (expression->base.kind == EXPR_SIZEOF) {
 482                 print_string("sizeof");
 483         } else {
 484                 assert(expression->base.kind == EXPR_ALIGNOF);
 485                 print_string("__alignof__");
 486         }
 487         if (expression->tp_expression != NULL) {
 488                 /* PREC_TOP: always print the '()' here, sizeof x is right but unusual */
 489                 print_expression_prec(expression->tp_expression, PREC_TOP);
 490         } else {
 491                 print_string("(");
 492                 print_type(expression->type);
 493                 print_string(")");
 494         }
 495 }
 496
 497 /**
 498  * Prints a builtin constant expression.
 499  *
 500  * @param expression   the builtin constant expression
 501  */
 502 static void print_builtin_constant(const builtin_constant_expression_t *expression)
 503 {
 504         print_string("__builtin_constant_p(");
 505         print_assignment_expression(expression->value);
 506         print_string(")");
 507 }
 508
 509 /**
 510  * Prints a builtin types compatible expression.
 511  *
 512  * @param expression   the builtin types compatible expression
 513  */
 514 static void print_builtin_types_compatible(
 515                 const builtin_types_compatible_expression_t *expression)
 516 {
 517         print_string("__builtin_types_compatible_p(");
 518         print_type(expression->left);
 519         print_string(", ");
 520         print_type(expression->right);
 521         print_string(")");
 522 }
 523
 524 /**
 525  * Prints a conditional expression.
 526  *
 527  * @param expression   the conditional expression
 528  */
 529 static void print_conditional(const conditional_expression_t *expression)
 530 {
 531         print_expression_prec(expression->condition, PREC_LOGICAL_OR);
 532         if (expression->true_expression != NULL) {
 533                 print_string(" ? ");
 534                 print_expression_prec(expression->true_expression, PREC_EXPRESSION);
 535                 print_string(" : ");
 536         } else {
 537                 print_string(" ?: ");
 538         }
 539         precedence_t prec = c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL;
 540         print_expression_prec(expression->false_expression, prec);
 541 }
 542
 543 /**
 544  * Prints a va_start expression.
 545  *
 546  * @param expression   the va_start expression
 547  */
 548 static void print_va_start(const va_start_expression_t *const expression)
 549 {
 550         print_string("__builtin_va_start(");
 551         print_assignment_expression(expression->ap);
 552         print_string(", ");
 553         print_string(expression->parameter->base.base.symbol->string);
 554         print_string(")");
 555 }
 556
 557 /**
 558  * Prints a va_arg expression.
 559  *
 560  * @param expression   the va_arg expression
 561  */
 562 static void print_va_arg(const va_arg_expression_t *expression)
 563 {
 564         print_string("__builtin_va_arg(");
 565         print_assignment_expression(expression->ap);
 566         print_string(", ");
 567         print_type(expression->base.type);
 568         print_string(")");
 569 }
 570
 571 /**
 572  * Prints a va_copy expression.
 573  *
 574  * @param expression   the va_copy expression
 575  */
 576 static void print_va_copy(const va_copy_expression_t *expression)
 577 {
 578         print_string("__builtin_va_copy(");
 579         print_assignment_expression(expression->dst);
 580         print_string(", ");
 581         print_assignment_expression(expression->src);
 582         print_string(")");
 583 }
 584
 585 /**
 586  * Prints a select expression (. or ->).
 587  *
 588  * @param expression   the select expression
 589  */
 590 static void print_select(const select_expression_t *expression)
 591 {
 592         print_expression_prec(expression->compound, PREC_POSTFIX);
 593         /* do not print anything for anonymous struct/union selects
 594          * FIXME: if the anonymous select was a '->' this will print '.'
 595          */
 596         if (expression->compound_entry->base.symbol == NULL)
 597                 return;
 598
 599         if (is_type_pointer(skip_typeref(expression->compound->base.type))) {
 600                 print_string("->");
 601         } else {
 602                 print_string(".");
 603         }
 604         print_string(expression->compound_entry->base.symbol->string);
 605 }
 606
 607 /**
 608  * Prints a type classify expression.
 609  *
 610  * @param expr   the type classify expression
 611  */
 612 static void print_classify_type_expression(
 613         const classify_type_expression_t *const expr)
 614 {
 615         print_string("__builtin_classify_type(");
 616         print_assignment_expression(expr->type_expression);
 617         print_string(")");
 618 }
 619
 620 /**
 621  * Prints a designator.
 622  *
 623  * @param designator  the designator
 624  */
 625 static void print_designator(const designator_t *designator)
 626 {
 627         for ( ; designator != NULL; designator = designator->next) {
 628                 if (designator->symbol == NULL) {
 629                         print_string("[");
 630                         print_expression(designator->array_index);
 631                         print_string("]");
 632                 } else {
 633                         print_string(".");
 634                         print_string(designator->symbol->string);
 635                 }
 636         }
 637 }
 638
 639 /**
 640  * Prints an offsetof expression.
 641  *
 642  * @param expression   the offset expression
 643  */
 644 static void print_offsetof_expression(const offsetof_expression_t *expression)
 645 {
 646         print_string("__builtin_offsetof(");
 647         print_type(expression->type);
 648         print_string(",");
 649         print_designator(expression->designator);
 650         print_string(")");
 651 }
 652
 653 /**
 654  * Prints a statement expression.
 655  *
 656  * @param expression   the statement expression
 657  */
 658 static void print_statement_expression(const statement_expression_t *expression)
 659 {
 660         print_string("(");
 661         print_statement(expression->statement);
 662         print_string(")");
 663 }
 664
 665 /**
 666  * Prints an expression with parenthesis if needed.
 667  *
 668  * @param expression  the expression to print
 669  * @param top_prec    the precedence of the user of this expression.
 670  */
 671 static void print_expression_prec(const expression_t *expression, unsigned top_prec)
 672 {
 673         if (expression->kind == EXPR_UNARY_CAST
 674             && expression->base.implicit && !print_implicit_casts) {
 675                 expression = expression->unary.value;
 676         }
 677
 678         bool parenthesized =
 679                 expression->base.parenthesized                 ||
 680                 (print_parenthesis && top_prec != PREC_BOTTOM) ||
 681                 top_prec > get_expression_precedence(expression->base.kind);
 682
 683         if (parenthesized)
 684                 print_string("(");
 685         switch (expression->kind) {
 686         case EXPR_ERROR:
 687                 print_string("$error$");
 688                 break;
 689         case EXPR_WIDE_STRING_LITERAL:
 690         case EXPR_STRING_LITERAL:
 691                 print_string_literal(&expression->string_literal);
 692                 break;
 693         EXPR_LITERAL_CASES
 694                 print_literal(&expression->literal);
 695                 break;
 696         case EXPR_FUNCNAME:
 697                 print_funcname(&expression->funcname);
 698                 break;
 699         case EXPR_COMPOUND_LITERAL:
 700                 print_compound_literal(&expression->compound_literal);
 701                 break;
 702         case EXPR_CALL:
 703                 print_call_expression(&expression->call);
 704                 break;
 705         EXPR_BINARY_CASES
 706                 print_binary_expression(&expression->binary);
 707                 break;
 708         case EXPR_REFERENCE:
 709         case EXPR_REFERENCE_ENUM_VALUE:
 710                 print_reference_expression(&expression->reference);
 711                 break;
 712         case EXPR_ARRAY_ACCESS:
 713                 print_array_expression(&expression->array_access);
 714                 break;
 715         case EXPR_LABEL_ADDRESS:
 716                 print_label_address_expression(&expression->label_address);
 717                 break;
 718         EXPR_UNARY_CASES
 719                 print_unary_expression(&expression->unary);
 720                 break;
 721         case EXPR_SIZEOF:
 722         case EXPR_ALIGNOF:
 723                 print_typeprop_expression(&expression->typeprop);
 724                 break;
 725         case EXPR_BUILTIN_CONSTANT_P:
 726                 print_builtin_constant(&expression->builtin_constant);
 727                 break;
 728         case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
 729                 print_builtin_types_compatible(&expression->builtin_types_compatible);
 730                 break;
 731         case EXPR_CONDITIONAL:
 732                 print_conditional(&expression->conditional);
 733                 break;
 734         case EXPR_VA_START:
 735                 print_va_start(&expression->va_starte);
 736                 break;
 737         case EXPR_VA_ARG:
 738                 print_va_arg(&expression->va_arge);
 739                 break;
 740         case EXPR_VA_COPY:
 741                 print_va_copy(&expression->va_copye);
 742                 break;
 743         case EXPR_SELECT:
 744                 print_select(&expression->select);
 745                 break;
 746         case EXPR_CLASSIFY_TYPE:
 747                 print_classify_type_expression(&expression->classify_type);
 748                 break;
 749         case EXPR_OFFSETOF:
 750                 print_offsetof_expression(&expression->offsetofe);
 751                 break;
 752         case EXPR_STATEMENT:
 753                 print_statement_expression(&expression->statement);
 754                 break;
 755         case EXPR_INVALID:
 756                 panic("invalid expression found");
 757
 758 #if 0
 759         default:
 760                 /* TODO */
 761                 print_format("some expression of type %d", (int)expression->kind);
 762                 break;
 763 #endif
 764         }
 765         if (parenthesized)
 766                 print_string(")");
 767 }
 768
 769 /**
 770  * Print an compound statement.
 771  *
 772  * @param block  the compound statement
 773  */
 774 static void print_compound_statement(const compound_statement_t *block)
 775 {
 776         print_string("{\n");
 777         ++indent;
 778
 779         statement_t *statement = block->statements;
 780         while (statement != NULL) {
 781                 if (statement->base.kind == STATEMENT_CASE_LABEL)
 782                         --indent;
 783                 if (statement->kind != STATEMENT_LABEL)
 784                         print_indent();
 785                 print_statement(statement);
 786
 787                 statement = statement->base.next;
 788         }
 789         --indent;
 790         print_indent();
 791         print_string(block->stmt_expr ? "}" : "}\n");
 792 }
 793
 794 /**
 795  * Print a return statement.
 796  *
 797  * @param statement  the return statement
 798  */
 799 static void print_return_statement(const return_statement_t *statement)
 800 {
 801         expression_t const *const val = statement->value;
 802         if (val != NULL) {
 803                 print_string("return ");
 804                 print_expression(val);
 805                 print_string(";\n");
 806         } else {
 807                 print_string("return;\n");
 808         }
 809 }
 810
 811 /**
 812  * Print an expression statement.
 813  *
 814  * @param statement  the expression statement
 815  */
 816 static void print_expression_statement(const expression_statement_t *statement)
 817 {
 818         print_expression(statement->expression);
 819         print_string(";\n");
 820 }
 821
 822 /**
 823  * Print a goto statement.
 824  *
 825  * @param statement  the goto statement
 826  */
 827 static void print_goto_statement(const goto_statement_t *statement)
 828 {
 829         print_string("goto ");
 830         if (statement->expression != NULL) {
 831                 print_string("*");
 832                 print_expression(statement->expression);
 833         } else {
 834                 print_string(statement->label->base.symbol->string);
 835         }
 836         print_string(";\n");
 837 }
 838
 839 /**
 840  * Print a label statement.
 841  *
 842  * @param statement  the label statement
 843  */
 844 static void print_label_statement(const label_statement_t *statement)
 845 {
 846         print_format("%s:\n", statement->label->base.symbol->string);
 847         print_indent();
 848         print_statement(statement->statement);
 849 }
 850
 851 /**
 852  * Print an if statement.
 853  *
 854  * @param statement  the if statement
 855  */
 856 static void print_if_statement(const if_statement_t *statement)
 857 {
 858         print_string("if (");
 859         print_expression(statement->condition);
 860         print_string(") ");
 861         print_statement(statement->true_statement);
 862
 863         if (statement->false_statement != NULL) {
 864                 print_indent();
 865                 print_string("else ");
 866                 print_statement(statement->false_statement);
 867         }
 868 }
 869
 870 /**
 871  * Print a switch statement.
 872  *
 873  * @param statement  the switch statement
 874  */
 875 static void print_switch_statement(const switch_statement_t *statement)
 876 {
 877         print_string("switch (");
 878         print_expression(statement->expression);
 879         print_string(") ");
 880         print_statement(statement->body);
 881 }
 882
 883 /**
 884  * Print a case label (including the default label).
 885  *
 886  * @param statement  the case label statement
 887  */
 888 static void print_case_label(const case_label_statement_t *statement)
 889 {
 890         if (statement->expression == NULL) {
 891                 print_string("default:\n");
 892         } else {
 893                 print_string("case ");
 894                 print_expression(statement->expression);
 895                 if (statement->end_range != NULL) {
 896                         print_string(" ... ");
 897                         print_expression(statement->end_range);
 898                 }
 899                 print_string(":\n");
 900         }
 901         ++indent;
 902         if (statement->statement != NULL) {
 903                 if (statement->statement->base.kind == STATEMENT_CASE_LABEL) {
 904                         --indent;
 905                 }
 906                 print_indent();
 907                 print_statement(statement->statement);
 908         }
 909 }
 910
 911 static void print_typedef(const entity_t *entity)
 912 {
 913         print_string("typedef ");
 914         print_type_ext(entity->typedefe.type, entity->base.symbol, NULL);
 915         print_string(";");
 916 }
 917
 918 /**
 919  * returns true if the entity is a compiler generated one and has no real
 920  * correspondenc in the source file
 921  */
 922 static bool is_generated_entity(const entity_t *entity)
 923 {
 924         if (entity->kind == ENTITY_TYPEDEF)
 925                 return entity->typedefe.builtin;
 926
 927         if (is_declaration(entity))
 928                 return entity->declaration.implicit;
 929
 930         return false;
 931 }
 932
 933 /**
 934  * Print a declaration statement.
 935  *
 936  * @param statement   the statement
 937  */
 938 static void print_declaration_statement(
 939                 const declaration_statement_t *statement)
 940 {
 941         bool first = true;
 942         entity_t *entity = statement->declarations_begin;
 943         if (entity == NULL) {
 944                 print_string("/* empty declaration statement */\n");
 945                 return;
 946         }
 947
 948         entity_t *const end = statement->declarations_end->base.next;
 949         for (; entity != end; entity = entity->base.next) {
 950                 if (entity->kind == ENTITY_ENUM_VALUE)
 951                         continue;
 952                 if (is_generated_entity(entity))
 953                         continue;
 954
 955                 if (!first) {
 956                         print_indent();
 957                 } else {
 958                         first = false;
 959                 }
 960
 961                 print_entity(entity);
 962                 print_string("\n");
 963         }
 964 }
 965
 966 /**
 967  * Print a while statement.
 968  *
 969  * @param statement   the statement
 970  */
 971 static void print_while_statement(const while_statement_t *statement)
 972 {
 973         print_string("while (");
 974         print_expression(statement->condition);
 975         print_string(") ");
 976         print_statement(statement->body);
 977 }
 978
 979 /**
 980  * Print a do-while statement.
 981  *
 982  * @param statement   the statement
 983  */
 984 static void print_do_while_statement(const do_while_statement_t *statement)
 985 {
 986         print_string("do ");
 987         print_statement(statement->body);
 988         print_indent();
 989         print_string("while (");
 990         print_expression(statement->condition);
 991         print_string(");\n");
 992 }
 993
 994 /**
 995  * Print a for statement.
 996  *
 997  * @param statement   the statement
 998  */
 999 static void print_for_statement(const for_statement_t *statement)
1000 {
1001         print_string("for (");
1002         if (statement->initialisation != NULL) {
1003                 print_expression(statement->initialisation);
1004                 print_string(";");
1005         } else {
1006                 entity_t const *entity = statement->scope.entities;
1007                 for (; entity != NULL; entity = entity->base.next) {
1008                         if (is_generated_entity(entity))
1009                                 continue;
1010                         /* FIXME display of multiple declarations is wrong */
1011                         print_declaration(entity);
1012                 }
1013         }
1014         if (statement->condition != NULL) {
1015                 print_string(" ");
1016                 print_expression(statement->condition);
1017         }
1018         print_string(";");
1019         if (statement->step != NULL) {
1020                 print_string(" ");
1021                 print_expression(statement->step);
1022         }
1023         print_string(") ");
1024         print_statement(statement->body);
1025 }
1026
1027 /**
1028  * Print assembler arguments.
1029  *
1030  * @param arguments   the arguments
1031  */
1032 static void print_asm_arguments(asm_argument_t *arguments)
1033 {
1034         asm_argument_t *argument = arguments;
1035         for (; argument != NULL; argument = argument->next) {
1036                 if (argument != arguments)
1037                         print_string(", ");
1038
1039                 if (argument->symbol) {
1040                         print_format("[%s] ", argument->symbol->string);
1041                 }
1042                 print_quoted_string(&argument->constraints, '"', 1);
1043                 print_string(" (");
1044                 print_expression(argument->expression);
1045                 print_string(")");
1046         }
1047 }
1048
1049 /**
1050  * Print assembler clobbers.
1051  *
1052  * @param clobbers   the clobbers
1053  */
1054 static void print_asm_clobbers(asm_clobber_t *clobbers)
1055 {
1056         asm_clobber_t *clobber = clobbers;
1057         for (; clobber != NULL; clobber = clobber->next) {
1058                 if (clobber != clobbers)
1059                         print_string(", ");
1060
1061                 print_quoted_string(&clobber->clobber, '"', 1);
1062         }
1063 }
1064
1065 /**
1066  * Print an assembler statement.
1067  *
1068  * @param statement   the statement
1069  */
1070 static void print_asm_statement(const asm_statement_t *statement)
1071 {
1072         print_string("asm ");
1073         if (statement->is_volatile) {
1074                 print_string("volatile ");
1075         }
1076         print_string("(");
1077         print_quoted_string(&statement->asm_text, '"', 1);
1078         if (statement->outputs  == NULL &&
1079             statement->inputs   == NULL &&
1080             statement->clobbers == NULL)
1081                 goto end_of_print_asm_statement;
1082
1083         print_string(" : ");
1084         print_asm_arguments(statement->outputs);
1085         if (statement->inputs == NULL && statement->clobbers == NULL)
1086                 goto end_of_print_asm_statement;
1087
1088         print_string(" : ");
1089         print_asm_arguments(statement->inputs);
1090         if (statement->clobbers == NULL)
1091                 goto end_of_print_asm_statement;
1092
1093         print_string(" : ");
1094         print_asm_clobbers(statement->clobbers);
1095
1096 end_of_print_asm_statement:
1097         print_string(");\n");
1098 }
1099
1100 /**
1101  * Print a microsoft __try statement.
1102  *
1103  * @param statement   the statement
1104  */
1105 static void print_ms_try_statement(const ms_try_statement_t *statement)
1106 {
1107         print_string("__try ");
1108         print_statement(statement->try_statement);
1109         print_indent();
1110         if (statement->except_expression != NULL) {
1111                 print_string("__except(");
1112                 print_expression(statement->except_expression);
1113                 print_string(") ");
1114         } else {
1115                 print_string("__finally ");
1116         }
1117         print_statement(statement->final_statement);
1118 }
1119
1120 /**
1121  * Print a microsoft __leave statement.
1122  *
1123  * @param statement   the statement
1124  */
1125 static void print_leave_statement(const leave_statement_t *statement)
1126 {
1127         (void)statement;
1128         print_string("__leave;\n");
1129 }
1130
1131 /**
1132  * Print a statement.
1133  *
1134  * @param statement   the statement
1135  */
1136 void print_statement(const statement_t *statement)
1137 {
1138         switch (statement->kind) {
1139         case STATEMENT_EMPTY:
1140                 print_string(";\n");
1141                 break;
1142         case STATEMENT_COMPOUND:
1143                 print_compound_statement(&statement->compound);
1144                 break;
1145         case STATEMENT_RETURN:
1146                 print_return_statement(&statement->returns);
1147                 break;
1148         case STATEMENT_EXPRESSION:
1149                 print_expression_statement(&statement->expression);
1150                 break;
1151         case STATEMENT_LABEL:
1152                 print_label_statement(&statement->label);
1153                 break;
1154         case STATEMENT_GOTO:
1155                 print_goto_statement(&statement->gotos);
1156                 break;
1157         case STATEMENT_CONTINUE:
1158                 print_string("continue;\n");
1159                 break;
1160         case STATEMENT_BREAK:
1161                 print_string("break;\n");
1162                 break;
1163         case STATEMENT_IF:
1164                 print_if_statement(&statement->ifs);
1165                 break;
1166         case STATEMENT_SWITCH:
1167                 print_switch_statement(&statement->switchs);
1168                 break;
1169         case STATEMENT_CASE_LABEL:
1170                 print_case_label(&statement->case_label);
1171                 break;
1172         case STATEMENT_DECLARATION:
1173                 print_declaration_statement(&statement->declaration);
1174                 break;
1175         case STATEMENT_WHILE:
1176                 print_while_statement(&statement->whiles);
1177                 break;
1178         case STATEMENT_DO_WHILE:
1179                 print_do_while_statement(&statement->do_while);
1180                 break;
1181         case STATEMENT_FOR:
1182                 print_for_statement(&statement->fors);
1183                 break;
1184         case STATEMENT_ASM:
1185                 print_asm_statement(&statement->asms);
1186                 break;
1187         case STATEMENT_MS_TRY:
1188                 print_ms_try_statement(&statement->ms_try);
1189                 break;
1190         case STATEMENT_LEAVE:
1191                 print_leave_statement(&statement->leave);
1192                 break;
1193         case STATEMENT_INVALID:
1194                 print_string("$invalid statement$\n");
1195                 break;
1196         }
1197 }
1198
1199 /**
1200  * Print a storage class.
1201  *
1202  * @param storage_class   the storage class
1203  */
1204 static void print_storage_class(storage_class_tag_t storage_class)
1205 {
1206         switch (storage_class) {
1207         case STORAGE_CLASS_NONE:     return;
1208         case STORAGE_CLASS_TYPEDEF:  print_string("typedef ");  return;
1209         case STORAGE_CLASS_EXTERN:   print_string("extern ");   return;
1210         case STORAGE_CLASS_STATIC:   print_string("static ");   return;
1211         case STORAGE_CLASS_AUTO:     print_string("auto ");     return;
1212         case STORAGE_CLASS_REGISTER: print_string("register "); return;
1213         }
1214         panic("invalid storage class");
1215 }
1216
1217 /**
1218  * Print an initializer.
1219  *
1220  * @param initializer  the initializer
1221  */
1222 void print_initializer(const initializer_t *initializer)
1223 {
1224         if (initializer == NULL) {
1225                 print_string("{}");
1226                 return;
1227         }
1228
1229         switch (initializer->kind) {
1230         case INITIALIZER_VALUE: {
1231                 const initializer_value_t *value = &initializer->value;
1232                 print_assignment_expression(value->value);
1233                 return;
1234         }
1235         case INITIALIZER_LIST: {
1236                 assert(initializer->kind == INITIALIZER_LIST);
1237                 print_string("{ ");
1238                 const initializer_list_t *list = &initializer->list;
1239
1240                 for (size_t i = 0 ; i < list->len; ++i) {
1241                         const initializer_t *sub_init = list->initializers[i];
1242                         print_initializer(list->initializers[i]);
1243                         if (i < list->len-1) {
1244                                 if (sub_init == NULL || sub_init->kind != INITIALIZER_DESIGNATOR)
1245                                         print_string(", ");
1246                         }
1247                 }
1248                 print_string(" }");
1249                 return;
1250         }
1251         case INITIALIZER_STRING:
1252                 print_quoted_string(&initializer->string.string, '"', 1);
1253                 return;
1254         case INITIALIZER_WIDE_STRING:
1255                 print_quoted_string(&initializer->string.string, '"', 1);
1256                 return;
1257         case INITIALIZER_DESIGNATOR:
1258                 print_designator(initializer->designator.designator);
1259                 print_string(" = ");
1260                 return;
1261         }
1262
1263         panic("invalid initializer kind found");
1264 }
1265
1266 #if 0
1267 /**
1268  * Print microsoft extended declaration modifiers.
1269  */
1270 static void print_ms_modifiers(const declaration_t *declaration)
1271 {
1272         if ((c_mode & _MS) == 0)
1273                 return;
1274
1275         decl_modifiers_t modifiers = declaration->modifiers;
1276
1277         bool        ds_shown = false;
1278         const char *next     = "(";
1279
1280         if (declaration->base.kind == ENTITY_VARIABLE) {
1281                 variable_t *variable = (variable_t*)declaration;
1282                 if (variable->alignment != 0
1283                                 || variable->get_property_sym != NULL
1284                                 || variable->put_property_sym != NULL) {
1285                         if (!ds_shown) {
1286                                 print_string("__declspec");
1287                                 ds_shown = true;
1288                         }
1289
1290                         if (variable->alignment != 0) {
1291                                 print_string(next); next = ", "; print_format("align(%u)", variable->alignment);
1292                         }
1293                         if (variable->get_property_sym != NULL
1294                                         || variable->put_property_sym != NULL) {
1295                                 char *comma = "";
1296                                 print_string(next); next = ", "; print_string("property(");
1297                                 if (variable->get_property_sym != NULL) {
1298                                         print_format("get=%s", variable->get_property_sym->string);
1299                                         comma = ", ";
1300                                 }
1301                                 if (variable->put_property_sym != NULL)
1302                                         print_format("%sput=%s", comma, variable->put_property_sym->string);
1303                                 print_string(")");
1304                         }
1305                 }
1306         }
1307
1308         /* DM_FORCEINLINE handled outside. */
1309         if ((modifiers & ~DM_FORCEINLINE) != 0) {
1310                 if (!ds_shown) {
1311                         print_string("__declspec");
1312                         ds_shown = true;
1313                 }
1314                 if (modifiers & DM_DLLIMPORT) {
1315                         print_string(next); next = ", "; print_string("dllimport");
1316                 }
1317                 if (modifiers & DM_DLLEXPORT) {
1318                         print_string(next); next = ", "; print_string("dllexport");
1319                 }
1320                 if (modifiers & DM_THREAD) {
1321                         print_string(next); next = ", "; print_string("thread");
1322                 }
1323                 if (modifiers & DM_NAKED) {
1324                         print_string(next); next = ", "; print_string("naked");
1325                 }
1326                 if (modifiers & DM_THREAD) {
1327                         print_string(next); next = ", "; print_string("thread");
1328                 }
1329                 if (modifiers & DM_SELECTANY) {
1330                         print_string(next); next = ", "; print_string("selectany");
1331                 }
1332                 if (modifiers & DM_NOTHROW) {
1333                         print_string(next); next = ", "; print_string("nothrow");
1334                 }
1335                 if (modifiers & DM_NORETURN) {
1336                         print_string(next); next = ", "; print_string("noreturn");
1337                 }
1338                 if (modifiers & DM_NOINLINE) {
1339                         print_string(next); next = ", "; print_string("noinline");
1340                 }
1341                 if (modifiers & DM_DEPRECATED) {
1342                         print_string(next); next = ", "; print_string("deprecated");
1343                         if (declaration->deprecated_string != NULL)
1344                                 print_format("(\"%s\")",
1345                                         declaration->deprecated_string);
1346                 }
1347                 if (modifiers & DM_RESTRICT) {
1348                         print_string(next); next = ", "; print_string("restrict");
1349                 }
1350                 if (modifiers & DM_NOALIAS) {
1351                         print_string(next); next = ", "; print_string("noalias");
1352                 }
1353         }
1354
1355         if (ds_shown)
1356                 print_string(") ");
1357 }
1358 #endif
1359
1360 static void print_scope(const scope_t *scope)
1361 {
1362         const entity_t *entity = scope->entities;
1363         for ( ; entity != NULL; entity = entity->base.next) {
1364                 print_indent();
1365                 print_entity(entity);
1366                 print_string("\n");
1367         }
1368 }
1369
1370 static void print_namespace(const namespace_t *namespace)
1371 {
1372         print_string("namespace ");
1373         if (namespace->base.symbol != NULL) {
1374                 print_string(namespace->base.symbol->string);
1375                 print_string(" ");
1376         }
1377
1378         print_string("{\n");
1379         ++indent;
1380
1381         print_scope(&namespace->members);
1382
1383         --indent;
1384         print_indent();
1385         print_string("}\n");
1386 }
1387
1388 /**
1389  * Print a variable or function declaration
1390  */
1391 void print_declaration(const entity_t *entity)
1392 {
1393         assert(is_declaration(entity));
1394         const declaration_t *declaration = &entity->declaration;
1395
1396         print_storage_class((storage_class_tag_t)declaration->declared_storage_class);
1397         if (entity->kind == ENTITY_FUNCTION) {
1398                 function_t *function = (function_t*)declaration;
1399                 if (function->is_inline) {
1400                         if (declaration->modifiers & DM_FORCEINLINE) {
1401                                 print_string("__forceinline ");
1402                         } else if (declaration->modifiers & DM_MICROSOFT_INLINE) {
1403                                 print_string("__inline ");
1404                         } else {
1405                                 print_string("inline ");
1406                         }
1407                 }
1408         }
1409         //print_ms_modifiers(declaration);
1410         switch (entity->kind) {
1411                 case ENTITY_FUNCTION:
1412                         print_type_ext(entity->declaration.type, entity->base.symbol,
1413                                         &entity->function.parameters);
1414
1415                         if (entity->function.statement != NULL) {
1416                                 print_string("\n");
1417                                 print_indent();
1418                                 print_statement(entity->function.statement);
1419                                 return;
1420                         }
1421                         break;
1422
1423                 case ENTITY_VARIABLE:
1424                         if (entity->variable.thread_local)
1425                                 print_string("__thread ");
1426                         print_type_ext(declaration->type, declaration->base.symbol, NULL);
1427                         if (entity->variable.initializer != NULL) {
1428                                 print_string(" = ");
1429                                 print_initializer(entity->variable.initializer);
1430                         }
1431                         break;
1432
1433                 case ENTITY_COMPOUND_MEMBER:
1434                         print_type_ext(declaration->type, declaration->base.symbol, NULL);
1435                         if (entity->compound_member.bitfield) {
1436                                 print_format(" : %u", entity->compound_member.bit_size);
1437                         }
1438                         break;
1439
1440                 default:
1441                         print_type_ext(declaration->type, declaration->base.symbol, NULL);
1442                         break;
1443         }
1444         print_string(";");
1445 }
1446
1447 /**
1448  * Prints an expression.
1449  *
1450  * @param expression  the expression
1451  */
1452 void print_expression(const expression_t *expression)
1453 {
1454         print_expression_prec(expression, PREC_BOTTOM);
1455 }
1456
1457 /**
1458  * Print a declaration.
1459  *
1460  * @param declaration  the declaration
1461  */
1462 void print_entity(const entity_t *entity)
1463 {
1464         if (entity->base.namespc != NAMESPACE_NORMAL && entity->base.symbol == NULL)
1465                 return;
1466
1467         switch ((entity_kind_tag_t)entity->kind) {
1468         case ENTITY_VARIABLE:
1469         case ENTITY_PARAMETER:
1470         case ENTITY_COMPOUND_MEMBER:
1471         case ENTITY_FUNCTION:
1472                 print_declaration(entity);
1473                 return;
1474         case ENTITY_TYPEDEF:
1475                 print_typedef(entity);
1476                 return;
1477         case ENTITY_CLASS:
1478                 /* TODO */
1479                 print_string("class ");
1480                 print_string(entity->base.symbol->string);
1481                 print_string("; /* TODO */\n");
1482                 return;
1483         case ENTITY_STRUCT:
1484                 print_string("struct ");
1485                 goto print_compound;
1486         case ENTITY_UNION:
1487                 print_string("union ");
1488 print_compound:
1489                 print_string(entity->base.symbol->string);
1490                 if (entity->compound.complete) {
1491                         print_string(" ");
1492                         print_compound_definition(&entity->compound);
1493                 }
1494                 print_string(";");
1495                 return;
1496         case ENTITY_ENUM:
1497                 print_string("enum ");
1498                 print_string(entity->base.symbol->string);
1499                 print_string(" ");
1500                 print_enum_definition(&entity->enume);
1501                 print_string(";");
1502                 return;
1503         case ENTITY_NAMESPACE:
1504                 print_namespace(&entity->namespacee);
1505                 return;
1506         case ENTITY_LOCAL_LABEL:
1507                 print_string("__label__ ");
1508                 print_string(entity->base.symbol->string);
1509                 print_string(";");
1510                 return;
1511         case ENTITY_LABEL:
1512         case ENTITY_ENUM_VALUE:
1513                 panic("print_entity used on unexpected entity type");
1514         case ENTITY_INVALID:
1515                 break;
1516         }
1517         panic("Invalid entity type encountered");
1518 }
1519
1520 /**
1521  * Print the AST of a translation unit.
1522  *
1523  * @param unit   the translation unit
1524  */
1525 void print_ast(const translation_unit_t *unit)
1526 {
1527         entity_t *entity = unit->scope.entities;
1528         for ( ; entity != NULL; entity = entity->base.next) {
1529                 if (entity->kind == ENTITY_ENUM_VALUE)
1530                         continue;
1531                 if (entity->base.namespc != NAMESPACE_NORMAL
1532                                 && entity->base.symbol == NULL)
1533                         continue;
1534                 if (is_generated_entity(entity))
1535                         continue;
1536
1537                 print_indent();
1538                 print_entity(entity);
1539                 print_string("\n");
1540         }
1541 }
1542
1543 expression_classification_t is_constant_initializer(const initializer_t *initializer)
1544 {
1545         switch (initializer->kind) {
1546         case INITIALIZER_STRING:
1547         case INITIALIZER_WIDE_STRING:
1548         case INITIALIZER_DESIGNATOR:
1549                 return EXPR_CLASS_CONSTANT;
1550
1551         case INITIALIZER_VALUE:
1552                 return is_constant_expression(initializer->value.value);
1553
1554         case INITIALIZER_LIST: {
1555                 expression_classification_t all = EXPR_CLASS_CONSTANT;
1556                 for (size_t i = 0; i < initializer->list.len; ++i) {
1557                         initializer_t *sub_initializer = initializer->list.initializers[i];
1558                         expression_classification_t const cur = is_constant_initializer(sub_initializer);
1559                         if (all > cur) {
1560                                 all = cur;
1561                         }
1562                 }
1563                 return all;
1564         }
1565         }
1566         panic("invalid initializer kind found");
1567 }
1568
1569 /**
1570  * Checks if an expression references an object with a constant/known location
1571  * to the linker. Example:
1572  *  - "x", "*&x" with x being a global variable. The value of x need not be
1573  *         constant but the address of x is.
1574  *  - "a.b.c" when a has a constant/known location to the linker
1575  */
1576 static expression_classification_t is_object_with_linker_constant_address(
1577         const expression_t *expression)
1578 {
1579         switch (expression->kind) {
1580         case EXPR_UNARY_DEREFERENCE:
1581                 return is_linker_constant(expression->unary.value);
1582
1583         case EXPR_SELECT: {
1584                 type_t *base_type = skip_typeref(expression->select.compound->base.type);
1585                 if (is_type_pointer(base_type)) {
1586                         /* it's a -> */
1587                         return is_linker_constant(expression->select.compound);
1588                 } else {
1589                         return is_object_with_linker_constant_address(expression->select.compound);
1590                 }
1591         }
1592
1593         case EXPR_ARRAY_ACCESS: {
1594                 expression_classification_t const ref = is_linker_constant(expression->array_access.array_ref);
1595                 expression_classification_t const idx = is_constant_expression(expression->array_access.index);
1596                 return ref < idx ? ref : idx;
1597         }
1598
1599         case EXPR_REFERENCE: {
1600                 entity_t *entity = expression->reference.entity;
1601                 if (!is_declaration(entity))
1602                         return EXPR_CLASS_VARIABLE;
1603
1604                 switch ((storage_class_tag_t)entity->declaration.storage_class) {
1605                 case STORAGE_CLASS_NONE:
1606                 case STORAGE_CLASS_EXTERN:
1607                 case STORAGE_CLASS_STATIC:
1608                         return
1609                                 entity->kind != ENTITY_VARIABLE ||
1610                                 !entity->variable.thread_local ? EXPR_CLASS_CONSTANT :
1611                                 EXPR_CLASS_VARIABLE;
1612
1613                 case STORAGE_CLASS_REGISTER:
1614                 case STORAGE_CLASS_TYPEDEF:
1615                 case STORAGE_CLASS_AUTO:
1616                         break;
1617                 }
1618                 return EXPR_CLASS_VARIABLE;
1619         }
1620
1621         case EXPR_ERROR:
1622                 return EXPR_CLASS_ERROR;
1623         case EXPR_INVALID:
1624                 panic("invalid expression found");
1625
1626         default:
1627                 return EXPR_CLASS_VARIABLE;
1628         }
1629 }
1630
1631 expression_classification_t is_linker_constant(const expression_t *expression)
1632 {
1633         switch (expression->kind) {
1634         case EXPR_STRING_LITERAL:
1635         case EXPR_WIDE_STRING_LITERAL:
1636         case EXPR_FUNCNAME:
1637         case EXPR_LABEL_ADDRESS:
1638                 return EXPR_CLASS_CONSTANT;
1639
1640         case EXPR_UNARY_TAKE_ADDRESS:
1641                 return is_object_with_linker_constant_address(expression->unary.value);
1642
1643         case EXPR_UNARY_DEREFERENCE: {
1644                 type_t *real_type
1645                         = revert_automatic_type_conversion(expression->unary.value);
1646                 /* dereferencing a function is a NOP */
1647                 if (is_type_function(real_type)) {
1648                         return is_linker_constant(expression->unary.value);
1649                 }
1650                 /* FALLTHROUGH */
1651         }
1652
1653         case EXPR_UNARY_CAST: {
1654                 type_t *dest = skip_typeref(expression->base.type);
1655                 if (!is_type_pointer(dest) && (
1656                                 dest->kind != TYPE_ATOMIC                                               ||
1657                                 !(get_atomic_type_flags(dest->atomic.akind) & ATOMIC_TYPE_FLAG_INTEGER) ||
1658                                 get_atomic_type_size(dest->atomic.akind) < get_type_size(type_void_ptr)
1659                     ))
1660                         return EXPR_CLASS_VARIABLE;
1661
1662                 expression_classification_t const expr = is_constant_expression(expression->unary.value);
1663                 expression_classification_t const addr = is_linker_constant(expression->unary.value);
1664                 return expr > addr ? expr : addr;
1665         }
1666
1667         case EXPR_BINARY_ADD:
1668         case EXPR_BINARY_SUB: {
1669                 expression_t *const left  = expression->binary.left;
1670                 expression_t *const right = expression->binary.right;
1671                 type_t       *const ltype = skip_typeref(left->base.type);
1672                 type_t       *const rtype = skip_typeref(right->base.type);
1673
1674                 if (is_type_pointer(ltype)) {
1675                         expression_classification_t const l = is_linker_constant(left);
1676                         expression_classification_t const r = is_constant_expression(right);
1677                         return l < r ? l : r;
1678                 } else if (is_type_pointer(rtype)) {
1679                         expression_classification_t const l = is_constant_expression(left);
1680                         expression_classification_t const r = is_linker_constant(right);
1681                         return l < r ? l : r;
1682                 } else if (!is_type_valid(ltype) || !is_type_valid(rtype)) {
1683                         return EXPR_CLASS_ERROR;
1684                 } else {
1685                         return EXPR_CLASS_VARIABLE;
1686                 }
1687         }
1688
1689         case EXPR_REFERENCE: {
1690                 entity_t *entity = expression->reference.entity;
1691                 if (!is_declaration(entity))
1692                         return EXPR_CLASS_VARIABLE;
1693
1694                 type_t *type = skip_typeref(entity->declaration.type);
1695                 if (is_type_function(type))
1696                         return EXPR_CLASS_CONSTANT;
1697                 if (is_type_array(type)) {
1698                         return is_object_with_linker_constant_address(expression);
1699                 }
1700                 /* Prevent stray errors */
1701                 if (!is_type_valid(type))
1702                         return EXPR_CLASS_ERROR;
1703                 return EXPR_CLASS_VARIABLE;
1704         }
1705
1706         case EXPR_ARRAY_ACCESS: {
1707                 type_t *const type =
1708                         skip_typeref(revert_automatic_type_conversion(expression));
1709                 if (!is_type_array(type))
1710                         return EXPR_CLASS_VARIABLE;
1711                 expression_classification_t const ref = is_linker_constant(expression->array_access.array_ref);
1712                 expression_classification_t const idx = is_constant_expression(expression->array_access.index);
1713                 return ref < idx ? ref : idx;
1714         }
1715
1716         case EXPR_CONDITIONAL: {
1717                 expression_t *const c = expression->conditional.condition;
1718                 expression_classification_t const cclass = is_constant_expression(c);
1719                 if (cclass != EXPR_CLASS_CONSTANT)
1720                         return cclass;
1721
1722                 if (fold_constant_to_bool(c)) {
1723                         expression_t const *const t = expression->conditional.true_expression;
1724                         return is_linker_constant(t != NULL ? t : c);
1725                 } else {
1726                         return is_linker_constant(expression->conditional.false_expression);
1727                 }
1728         }
1729
1730         case EXPR_SELECT: {
1731                 entity_t *entity = expression->select.compound_entry;
1732                 if (!is_declaration(entity))
1733                         return EXPR_CLASS_VARIABLE;
1734                 type_t *type = skip_typeref(entity->declaration.type);
1735                 if (is_type_array(type)) {
1736                         /* arrays automatically convert to their address */
1737                         expression_t *compound  = expression->select.compound;
1738                         type_t       *base_type = skip_typeref(compound->base.type);
1739                         if (is_type_pointer(base_type)) {
1740                                 /* it's a -> */
1741                                 return is_linker_constant(compound);
1742                         } else {
1743                                 return is_object_with_linker_constant_address(compound);
1744                         }
1745                 }
1746                 return EXPR_CLASS_VARIABLE;
1747         }
1748
1749         case EXPR_ERROR:
1750                 return EXPR_CLASS_ERROR;
1751         case EXPR_INVALID:
1752                 panic("invalid expression found");
1753
1754         default:
1755                 return EXPR_CLASS_VARIABLE;
1756         }
1757 }
1758
1759 /**
1760  * Check if the given expression is a call to a builtin function
1761  * returning a constant result.
1762  */
1763 static expression_classification_t is_builtin_const_call(const expression_t *expression)
1764 {
1765         expression_t *function = expression->call.function;
1766         if (function->kind != EXPR_REFERENCE)
1767                 return EXPR_CLASS_VARIABLE;
1768         reference_expression_t *ref = &function->reference;
1769         if (ref->entity->kind != ENTITY_FUNCTION)
1770                 return EXPR_CLASS_VARIABLE;
1771
1772         switch (ref->entity->function.btk) {
1773         case bk_gnu_builtin_huge_val:
1774         case bk_gnu_builtin_huge_valf:
1775         case bk_gnu_builtin_huge_vall:
1776         case bk_gnu_builtin_inf:
1777         case bk_gnu_builtin_inff:
1778         case bk_gnu_builtin_infl:
1779         case bk_gnu_builtin_nan:
1780         case bk_gnu_builtin_nanf:
1781         case bk_gnu_builtin_nanl:
1782                 return EXPR_CLASS_CONSTANT;
1783         default:
1784                 return EXPR_CLASS_VARIABLE;
1785         }
1786
1787 }
1788
1789 static expression_classification_t is_constant_pointer(const expression_t *expression)
1790 {
1791         expression_classification_t const expr_class = is_constant_expression(expression);
1792         if (expr_class != EXPR_CLASS_VARIABLE)
1793                 return expr_class;
1794
1795         switch (expression->kind) {
1796         case EXPR_UNARY_CAST:
1797                 return is_constant_pointer(expression->unary.value);
1798         default:
1799                 return EXPR_CLASS_VARIABLE;
1800         }
1801 }
1802
1803 static expression_classification_t is_object_with_constant_address(const expression_t *expression)
1804 {
1805         switch (expression->kind) {
1806         case EXPR_SELECT: {
1807                 expression_t *compound      = expression->select.compound;
1808                 type_t       *compound_type = compound->base.type;
1809                 compound_type = skip_typeref(compound_type);
1810                 if (is_type_pointer(compound_type)) {
1811                         return is_constant_pointer(compound);
1812                 } else {
1813                         return is_object_with_constant_address(compound);
1814                 }
1815         }
1816
1817         case EXPR_ARRAY_ACCESS: {
1818                 array_access_expression_t const* const array_access =
1819                         &expression->array_access;
1820                 expression_classification_t const idx_class = is_constant_expression(array_access->index);
1821                 if (idx_class != EXPR_CLASS_CONSTANT)
1822                         return idx_class;
1823                 expression_classification_t const ref_addr = is_object_with_constant_address(array_access->array_ref);
1824                 expression_classification_t const ref_ptr  = is_constant_pointer(array_access->array_ref);
1825                 return ref_addr > ref_ptr ? ref_addr : ref_ptr;
1826         }
1827
1828         case EXPR_UNARY_DEREFERENCE:
1829                 return is_constant_pointer(expression->unary.value);
1830
1831         case EXPR_ERROR:
1832                 return EXPR_CLASS_ERROR;
1833         case EXPR_INVALID:
1834                 panic("invalid expression found");
1835
1836         default:
1837                 return EXPR_CLASS_VARIABLE;
1838         }
1839 }
1840
1841 expression_classification_t is_constant_expression(const expression_t *expression)
1842 {
1843         switch (expression->kind) {
1844         EXPR_LITERAL_CASES
1845         case EXPR_CLASSIFY_TYPE:
1846         case EXPR_OFFSETOF:
1847         case EXPR_ALIGNOF:
1848         case EXPR_BUILTIN_CONSTANT_P:
1849         case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1850         case EXPR_REFERENCE_ENUM_VALUE:
1851                 return EXPR_CLASS_CONSTANT;
1852
1853         case EXPR_SIZEOF: {
1854                 type_t *const type = skip_typeref(expression->typeprop.type);
1855                 return
1856                         !is_type_array(type) || !type->array.is_vla ? EXPR_CLASS_CONSTANT :
1857                         EXPR_CLASS_VARIABLE;
1858         }
1859
1860         case EXPR_STRING_LITERAL:
1861         case EXPR_WIDE_STRING_LITERAL:
1862         case EXPR_FUNCNAME:
1863         case EXPR_LABEL_ADDRESS:
1864         case EXPR_SELECT:
1865         case EXPR_VA_START:
1866         case EXPR_VA_ARG:
1867         case EXPR_VA_COPY:
1868         case EXPR_STATEMENT:
1869         case EXPR_UNARY_POSTFIX_INCREMENT:
1870         case EXPR_UNARY_POSTFIX_DECREMENT:
1871         case EXPR_UNARY_PREFIX_INCREMENT:
1872         case EXPR_UNARY_PREFIX_DECREMENT:
1873         case EXPR_UNARY_ASSUME: /* has VOID type */
1874         case EXPR_UNARY_DEREFERENCE:
1875         case EXPR_UNARY_DELETE:
1876         case EXPR_UNARY_DELETE_ARRAY:
1877         case EXPR_UNARY_THROW:
1878         case EXPR_BINARY_ASSIGN:
1879         case EXPR_BINARY_MUL_ASSIGN:
1880         case EXPR_BINARY_DIV_ASSIGN:
1881         case EXPR_BINARY_MOD_ASSIGN:
1882         case EXPR_BINARY_ADD_ASSIGN:
1883         case EXPR_BINARY_SUB_ASSIGN:
1884         case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1885         case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1886         case EXPR_BINARY_BITWISE_AND_ASSIGN:
1887         case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1888         case EXPR_BINARY_BITWISE_OR_ASSIGN:
1889         case EXPR_BINARY_COMMA:
1890         case EXPR_ARRAY_ACCESS:
1891                 return EXPR_CLASS_VARIABLE;
1892
1893         case EXPR_REFERENCE: {
1894                 type_t *const type = skip_typeref(expression->base.type);
1895                 return is_type_valid(type) ? EXPR_CLASS_VARIABLE : EXPR_CLASS_ERROR;
1896         }
1897
1898         case EXPR_UNARY_TAKE_ADDRESS:
1899                 return is_object_with_constant_address(expression->unary.value);
1900
1901         case EXPR_CALL:
1902                 return is_builtin_const_call(expression);
1903
1904         case EXPR_UNARY_NEGATE:
1905         case EXPR_UNARY_PLUS:
1906         case EXPR_UNARY_BITWISE_NEGATE:
1907         case EXPR_UNARY_NOT:
1908                 return is_constant_expression(expression->unary.value);
1909
1910         case EXPR_UNARY_CAST: {
1911                 type_t *const type = skip_typeref(expression->base.type);
1912                 if (is_type_scalar(type))
1913                         return is_constant_expression(expression->unary.value);
1914                 if (!is_type_valid(type))
1915                         return EXPR_CLASS_ERROR;
1916                 return EXPR_CLASS_VARIABLE;
1917         }
1918
1919         case EXPR_BINARY_ADD:
1920         case EXPR_BINARY_SUB:
1921         case EXPR_BINARY_MUL:
1922         case EXPR_BINARY_DIV:
1923         case EXPR_BINARY_MOD:
1924         case EXPR_BINARY_EQUAL:
1925         case EXPR_BINARY_NOTEQUAL:
1926         case EXPR_BINARY_LESS:
1927         case EXPR_BINARY_LESSEQUAL:
1928         case EXPR_BINARY_GREATER:
1929         case EXPR_BINARY_GREATEREQUAL:
1930         case EXPR_BINARY_BITWISE_AND:
1931         case EXPR_BINARY_BITWISE_OR:
1932         case EXPR_BINARY_BITWISE_XOR:
1933         case EXPR_BINARY_SHIFTLEFT:
1934         case EXPR_BINARY_SHIFTRIGHT:
1935         case EXPR_BINARY_ISGREATER:
1936         case EXPR_BINARY_ISGREATEREQUAL:
1937         case EXPR_BINARY_ISLESS:
1938         case EXPR_BINARY_ISLESSEQUAL:
1939         case EXPR_BINARY_ISLESSGREATER:
1940         case EXPR_BINARY_ISUNORDERED: {
1941                 expression_classification_t const l = is_constant_expression(expression->binary.left);
1942                 expression_classification_t const r = is_constant_expression(expression->binary.right);
1943                 return l < r ? l : r;
1944         }
1945
1946         case EXPR_BINARY_LOGICAL_AND: {
1947                 expression_t const         *const left   = expression->binary.left;
1948                 expression_classification_t const lclass = is_constant_expression(left);
1949                 if (lclass != EXPR_CLASS_CONSTANT)
1950                         return lclass;
1951                 if (!fold_constant_to_bool(left))
1952                         return EXPR_CLASS_CONSTANT;
1953                 return is_constant_expression(expression->binary.right);
1954         }
1955
1956         case EXPR_BINARY_LOGICAL_OR: {
1957                 expression_t const         *const left   = expression->binary.left;
1958                 expression_classification_t const lclass = is_constant_expression(left);
1959                 if (lclass != EXPR_CLASS_CONSTANT)
1960                         return lclass;
1961                 if (fold_constant_to_bool(left))
1962                         return EXPR_CLASS_CONSTANT;
1963                 return is_constant_expression(expression->binary.right);
1964         }
1965
1966         case EXPR_COMPOUND_LITERAL:
1967                 return is_constant_initializer(expression->compound_literal.initializer);
1968
1969         case EXPR_CONDITIONAL: {
1970                 expression_t               *const condition = expression->conditional.condition;
1971                 expression_classification_t const cclass    = is_constant_expression(condition);
1972                 if (cclass != EXPR_CLASS_CONSTANT)
1973                         return cclass;
1974
1975                 if (fold_constant_to_bool(condition)) {
1976                         expression_t const *const t = expression->conditional.true_expression;
1977                         return t == NULL ? EXPR_CLASS_CONSTANT : is_constant_expression(t);
1978                 } else {
1979                         return is_constant_expression(expression->conditional.false_expression);
1980                 }
1981         }
1982
1983         case EXPR_ERROR:
1984                 return EXPR_CLASS_ERROR;
1985         case EXPR_INVALID:
1986                 break;
1987         }
1988         panic("invalid expression found (is constant expression)");
1989 }
1990
1991 void init_ast(void)
1992 {
1993         obstack_init(&ast_obstack);
1994 }
1995
1996 void exit_ast(void)
1997 {
1998         obstack_free(&ast_obstack, NULL);
1999 }