show-parse.c

   1 /*
   2  * sparse/show-parse.c
   3  *
   4  * Copyright (C) 2003 Transmeta Corp.
   5  *               2003 Linus Torvalds
   6  *
   7  *  Licensed under the Open Software License version 1.1
   8  *
   9  * Print out results of parsing for debugging and testing.
  10  */
  11 #include <stdarg.h>
  12 #include <stdlib.h>
  13 #include <stdio.h>
  14 #include <string.h>
  15 #include <ctype.h>
  16 #include <unistd.h>
  17 #include <fcntl.h>
  18
  19 #include "lib.h"
  20 #include "token.h"
  21 #include "parse.h"
  22 #include "symbol.h"
  23 #include "scope.h"
  24 #include "expression.h"
  25 #include "target.h"
  26
  27 static int show_symbol_expr(struct symbol *sym);
  28
  29 static void do_debug_symbol(struct symbol *sym, int indent)
  30 {
  31         static const char indent_string[] = "                                  ";
  32         static const char *typestr[] = {
  33                 "base", "node", "ptr.", "fn..",
  34                 "arry", "strt", "unin", "enum",
  35                 "tdef", "tpof", "memb", "bitf",
  36                 "labl"
  37         };
  38
  39         if (!sym)
  40                 return;
  41         fprintf(stderr, "%.*s%s%3d:%lu %lx %s (as: %d, context: %x:%x) %p (%s:%d:%d)\n",
  42                 indent, indent_string, typestr[sym->type],
  43                 sym->bit_size, sym->ctype.alignment,
  44                 sym->ctype.modifiers, show_ident(sym->ident),
  45                 sym->ctype.as, sym->ctype.context, sym->ctype.contextmask,
  46                 sym, input_streams[sym->pos.stream].name, sym->pos.line, sym->pos.pos);
  47         if (sym->type == SYM_FN) {
  48                 int i = 1;
  49                 struct symbol *arg;
  50                 FOR_EACH_PTR(sym->arguments, arg) {
  51                         fprintf(stderr, "< arg%d:\n", i);
  52                         do_debug_symbol(arg, 0);
  53                         fprintf(stderr, "  end arg%d >\n", i);
  54                         i++;
  55                 } END_FOR_EACH_PTR;
  56         }
  57         do_debug_symbol(sym->ctype.base_type, indent+2);
  58 }
  59
  60 void debug_symbol(struct symbol *sym)
  61 {
  62         do_debug_symbol(sym, 0);
  63 }
  64
  65 /*
  66  * Symbol type printout. The type system is by far the most
  67  * complicated part of C - everything else is trivial.
  68  */
  69 const char *modifier_string(unsigned long mod)
  70 {
  71         static char buffer[100];
  72         char *p = buffer;
  73         const char *res,**ptr, *names[] = {
  74                 "auto", "register", "static", "extern",
  75                 "const", "volatile", "[signed]", "[unsigned]",
  76                 "[char]", "[short]", "[long]", "[long]",
  77                 "[typdef]", "[structof]", "[unionof]", "[enum]",
  78                 "[typeof]", "[attribute]", "inline", "[addressable]",
  79                 "[nocast]", "[noderef]",
  80                 NULL
  81         };
  82         ptr = names;
  83         while ((res = *ptr++) != NULL) {
  84                 if (mod & 1) {
  85                         char c;
  86                         while ((c = *res++) != '\0')
  87                                 *p++ = c;
  88                         *p++ = ' ';
  89                 }
  90                 mod >>= 1;
  91         }
  92         *p = 0;
  93         return buffer;
  94 }
  95
  96 void show_struct_member(struct symbol *sym, void *data, int flags)
  97 {
  98         if (flags & ITERATE_FIRST)
  99                 printf(" {\n\t");
 100         printf("%s:%d:%ld at offset %ld", show_ident(sym->ident), sym->bit_size, sym->ctype.alignment, sym->offset);
 101         if (sym->fieldwidth)
 102                 printf("[%d..%d]", sym->bit_offset, sym->bit_offset+sym->fieldwidth-1);
 103         if (flags & ITERATE_LAST)
 104                 printf("\n} ");
 105         else
 106                 printf(", ");
 107 }
 108
 109 static void show_one_symbol(struct symbol *sym, void *sep, int flags)
 110 {
 111         show_symbol(sym);
 112         if (!(flags & ITERATE_LAST))
 113                 printf("%s", (const char *)sep);
 114 }
 115
 116 void show_symbol_list(struct symbol_list *list, const char *sep)
 117 {
 118         symbol_iterate(list, show_one_symbol, (void *)sep);
 119 }
 120
 121 struct type_name {
 122         char *start;
 123         char *end;
 124 };
 125
 126 static void prepend(struct type_name *name, const char *fmt, ...)
 127 {
 128         static char buffer[512];
 129         int n;
 130
 131         va_list args;
 132         va_start(args, fmt);
 133         n = vsprintf(buffer, fmt, args);
 134         va_end(args);
 135
 136         name->start -= n;
 137         memcpy(name->start, buffer, n);
 138 }
 139
 140 static void append(struct type_name *name, const char *fmt, ...)
 141 {
 142         static char buffer[512];
 143         int n;
 144
 145         va_list args;
 146         va_start(args, fmt);
 147         n = vsprintf(buffer, fmt, args);
 148         va_end(args);
 149
 150         memcpy(name->end, buffer, n);
 151         name->end += n;
 152 }
 153
 154 static void do_show_type(struct symbol *sym, struct type_name *name)
 155 {
 156         int i, modlen;
 157         const char *mod;
 158         static struct ctype_name {
 159                 struct symbol *sym;
 160                 char *name;
 161         } typenames[] = {
 162                 { & char_ctype,  "char" },
 163                 { &uchar_ctype,  "unsigned char" },
 164                 { & short_ctype, "short" },
 165                 { &ushort_ctype, "unsigned short" },
 166                 { & int_ctype,   "int" },
 167                 { &uint_ctype,   "unsigned int" },
 168                 { & long_ctype,  "long" },
 169                 { &ulong_ctype,  "unsigned long" },
 170                 { & llong_ctype, "long long" },
 171                 { &ullong_ctype, "unsigned long long" },
 172
 173                 { &void_ctype,   "void" },
 174                 { &bool_ctype,   "bool" },
 175                 { &string_ctype, "string" },
 176
 177                 { &float_ctype,  "float" },
 178                 { &double_ctype, "double" },
 179                 { &ldouble_ctype,"long double" },
 180         };
 181
 182         if (!sym)
 183                 return;
 184
 185         for (i = 0; i < sizeof(typenames)/sizeof(typenames[0]); i++) {
 186                 if (typenames[i].sym == sym) {
 187                         int len = strlen(typenames[i].name);
 188                         *--name->start = ' ';
 189                         name->start -= len;
 190                         memcpy(name->start, typenames[i].name, len);
 191                         return;
 192                 }
 193         }
 194
 195         /* Prepend */
 196         switch (sym->type) {
 197         case SYM_PTR:
 198                 prepend(name, "*");
 199                 break;
 200         case SYM_FN:
 201                 prepend(name, "( ");
 202                 break;
 203         case SYM_STRUCT:
 204                 prepend(name, "struct %s ", show_ident(sym->ident));
 205                 return;
 206
 207         case SYM_UNION:
 208                 prepend(name, "union %s ", show_ident(sym->ident));
 209                 return;
 210
 211         case SYM_ENUM:
 212                 prepend(name, "enum %s ", show_ident(sym->ident));
 213                 return;
 214
 215         case SYM_NODE:
 216                 append(name, "%s", show_ident(sym->ident));
 217                 break;
 218
 219         case SYM_BITFIELD:
 220                 append(name, ":%d", sym->fieldwidth);
 221                 break;
 222
 223         case SYM_LABEL:
 224                 append(name, "label(%s:%p)", show_ident(sym->ident), sym);
 225                 break;
 226
 227         case SYM_ARRAY:
 228                 break;
 229
 230         default:
 231                 prepend(name, "unknown type %d", sym->type);
 232                 return;
 233         }
 234
 235         mod = modifier_string(sym->ctype.modifiers);
 236         modlen = strlen(mod);
 237         name->start -= modlen;
 238         memcpy(name->start, mod, modlen);
 239
 240         do_show_type(sym->ctype.base_type, name);
 241
 242         /* Postpend */
 243         if (sym->ctype.as)
 244                 append(name, "<asn:%d>", sym->ctype.as);
 245
 246         switch (sym->type) {
 247         case SYM_PTR:
 248                 return;
 249
 250         case SYM_FN:
 251                 append(name, " )( ... )");
 252                 return;
 253
 254         case SYM_ARRAY:
 255                 append(name, "[%lld]", get_expression_value(sym->array_size));
 256                 return;
 257         default:
 258                 break;
 259         }
 260 }
 261
 262 void show_type(struct symbol *sym)
 263 {
 264         char array[200];
 265         struct type_name name;
 266
 267         name.start = name.end = array+100;
 268         do_show_type(sym, &name);
 269         *name.end = 0;
 270         printf("%s", name.start);
 271 }
 272
 273 const char *show_typename(struct symbol *sym)
 274 {
 275         static char array[200];
 276         struct type_name name;
 277
 278         name.start = name.end = array+100;
 279         do_show_type(sym, &name);
 280         *name.end = 0;
 281         return name.start;
 282 }
 283
 284 void show_symbol(struct symbol *sym)
 285 {
 286         struct symbol *type;
 287
 288         if (!sym)
 289                 return;
 290
 291         if (sym->ctype.alignment)
 292                 printf(".align %ld\n", sym->ctype.alignment);
 293
 294         show_type(sym);
 295         type = sym->ctype.base_type;
 296         if (!type)
 297                 return;
 298
 299         /*
 300          * Show actual implementation information
 301          */
 302         switch (type->type) {
 303         case SYM_STRUCT:
 304                 symbol_iterate(type->symbol_list, show_struct_member, NULL);
 305                 break;
 306
 307         case SYM_UNION:
 308                 symbol_iterate(type->symbol_list, show_struct_member, NULL);
 309                 break;
 310
 311         case SYM_FN: {
 312                 struct statement *stmt = type->stmt;
 313                 if (stmt) {
 314                         int val;
 315                         printf("\n");
 316                         val = show_statement(stmt);
 317                         if (val)
 318                                 printf("\tmov.%d\t\tretval,%d\n", stmt->ret->bit_size, val);
 319                         printf("\tret\n");
 320                 }
 321                 break;
 322         }
 323
 324         default:
 325                 break;
 326         }
 327
 328         if (sym->initializer) {
 329                 printf(" = \n");
 330                 show_expression(sym->initializer);
 331         }
 332 }
 333
 334 static int show_symbol_init(struct symbol *sym);
 335
 336 static int new_pseudo(void)
 337 {
 338         static int nr = 0;
 339         return ++nr;
 340 }
 341
 342 static int new_label(void)
 343 {
 344         static int label = 0;
 345         return ++label;
 346 }
 347
 348 static void show_switch_statement(struct statement *stmt)
 349 {
 350         int val = show_expression(stmt->switch_expression);
 351         struct symbol *sym;
 352         printf("\tswitch v%d\n", val);
 353
 354         /*
 355          * Debugging only: Check that the case list is correct
 356          * by printing it out.
 357          *
 358          * This is where a _real_ back-end would go through the
 359          * cases to decide whether to use a lookup table or a
 360          * series of comparisons etc
 361          */
 362         printf("# case table:\n");
 363         FOR_EACH_PTR(stmt->switch_case->symbol_list, sym) {
 364                 struct statement *case_stmt = sym->stmt;
 365                 struct expression *expr = case_stmt->case_expression;
 366                 struct expression *to = case_stmt->case_to;
 367
 368                 if (!expr) {
 369                         printf("    default");
 370                 } else {
 371                         if (expr->type == EXPR_VALUE) {
 372                                 printf("    case %lld", expr->value);
 373                                 if (to) {
 374                                         if (to->type == EXPR_VALUE) {
 375                                                 printf(" .. %lld", to->value);
 376                                         } else {
 377                                                 printf(" .. what?");
 378                                         }
 379                                 }
 380                         } else
 381                                 printf("    what?");
 382                 }
 383                 printf(": .L%p\n", sym->bb_target);
 384         } END_FOR_EACH_PTR;
 385         printf("# end case table\n");
 386
 387         show_statement(stmt->switch_statement);
 388
 389         if (stmt->switch_break->used)
 390                 printf(".L%p:\n", stmt->switch_break->bb_target);
 391 }
 392
 393 static void show_symbol_decl(struct symbol_list *syms)
 394 {
 395         struct symbol *sym;
 396         FOR_EACH_PTR(syms, sym) {
 397                 show_symbol_init(sym);
 398         } END_FOR_EACH_PTR;
 399 }
 400
 401 static int show_return_stmt(struct statement *stmt);
 402
 403 /*
 404  * Print out a statement
 405  */
 406 int show_statement(struct statement *stmt)
 407 {
 408         if (!stmt)
 409                 return 0;
 410         switch (stmt->type) {
 411         case STMT_RETURN:
 412                 return show_return_stmt(stmt);
 413         case STMT_COMPOUND: {
 414                 struct statement *s;
 415                 int last = 0;
 416
 417                 show_symbol_decl(stmt->syms);
 418                 FOR_EACH_PTR(stmt->stmts, s) {
 419                         last = show_statement(s);
 420                 } END_FOR_EACH_PTR;
 421                 if (stmt->ret) {
 422                         int addr, bits;
 423                         printf(".L%p:\n", stmt->ret);
 424                         addr = show_symbol_expr(stmt->ret);
 425                         bits = stmt->ret->bit_size;
 426                         last = new_pseudo();
 427                         printf("\tld.%d\t\tv%d,[v%d]\n", bits, last, addr);
 428                 }
 429                 return last;
 430         }
 431
 432         case STMT_EXPRESSION:
 433                 return show_expression(stmt->expression);
 434         case STMT_IF: {
 435                 int val, target;
 436                 struct expression *cond = stmt->if_conditional;
 437
 438 /* This is only valid if nobody can jump into the "dead" statement */
 439 #if 0
 440                 if (cond->type == EXPR_VALUE) {
 441                         struct statement *s = stmt->if_true;
 442                         if (!cond->value)
 443                                 s = stmt->if_false;
 444                         show_statement(s);
 445                         break;
 446                 }
 447 #endif
 448                 val = show_expression(cond);
 449                 target = new_label();
 450                 printf("\tje\t\tv%d,.L%d\n", val, target);
 451                 show_statement(stmt->if_true);
 452                 if (stmt->if_false) {
 453                         int last = new_label();
 454                         printf("\tjmp\t\t.L%d\n", last);
 455                         printf(".L%d:\n", target);
 456                         target = last;
 457                         show_statement(stmt->if_false);
 458                 }
 459                 printf(".L%d:\n", target);
 460                 break;
 461         }
 462         case STMT_SWITCH:
 463                 show_switch_statement(stmt);
 464                 break;
 465
 466         case STMT_CASE:
 467                 printf(".L%p:\n", stmt->case_label);
 468                 show_statement(stmt->case_statement);
 469                 break;
 470
 471         case STMT_ITERATOR: {
 472                 struct statement  *pre_statement = stmt->iterator_pre_statement;
 473                 struct expression *pre_condition = stmt->iterator_pre_condition;
 474                 struct statement  *statement = stmt->iterator_statement;
 475                 struct statement  *post_statement = stmt->iterator_post_statement;
 476                 struct expression *post_condition = stmt->iterator_post_condition;
 477                 int val, loop_top = 0, loop_bottom = 0;
 478
 479                 show_symbol_decl(stmt->iterator_syms);
 480                 show_statement(pre_statement);
 481                 if (pre_condition) {
 482                         if (pre_condition->type == EXPR_VALUE) {
 483                                 if (!pre_condition->value) {
 484                                         loop_bottom = new_label();
 485                                         printf("\tjmp\t\t.L%d\n", loop_bottom);
 486                                 }
 487                         } else {
 488                                 loop_bottom = new_label();
 489                                 val = show_expression(pre_condition);
 490                                 printf("\tje\t\tv%d, .L%d\n", val, loop_bottom);
 491                         }
 492                 }
 493                 if (!post_condition || post_condition->type != EXPR_VALUE || post_condition->value) {
 494                         loop_top = new_label();
 495                         printf(".L%d:\n", loop_top);
 496                 }
 497                 show_statement(statement);
 498                 if (stmt->iterator_continue->used)
 499                         printf(".L%p:\n", stmt->iterator_continue);
 500                 show_statement(post_statement);
 501                 if (!post_condition) {
 502                         printf("\tjmp\t\t.L%d\n", loop_top);
 503                 } else if (post_condition->type == EXPR_VALUE) {
 504                         if (post_condition->value)
 505                                 printf("\tjmp\t\t.L%d\n", loop_top);
 506                 } else {
 507                         val = show_expression(post_condition);
 508                         printf("\tjne\t\tv%d, .L%d\n", val, loop_top);
 509                 }
 510                 if (stmt->iterator_break->used)
 511                         printf(".L%p:\n", stmt->iterator_break);
 512                 if (loop_bottom)
 513                         printf(".L%d:\n", loop_bottom);
 514                 break;
 515         }
 516         case STMT_NONE:
 517                 break;
 518
 519         case STMT_LABEL:
 520                 printf(".L%p:\n", stmt->label_identifier);
 521                 show_statement(stmt->label_statement);
 522                 break;
 523
 524         case STMT_GOTO:
 525                 if (stmt->goto_expression) {
 526                         int val = show_expression(stmt->goto_expression);
 527                         printf("\tgoto\t\t*v%d\n", val);
 528                 } else {
 529                         printf("\tgoto\t\t.L%p\n", stmt->goto_label->bb_target);
 530                 }
 531                 break;
 532         case STMT_ASM:
 533                 printf("\tasm( .... )\n");
 534                 break;
 535
 536         }
 537         return 0;
 538 }
 539
 540 static void show_one_statement(struct statement *stmt, void *sep, int flags)
 541 {
 542         show_statement(stmt);
 543         if (!(flags & ITERATE_LAST))
 544                 printf("%s", (const char *)sep);
 545 }
 546
 547 void show_statement_list(struct statement_list *stmt, const char *sep)
 548 {
 549         statement_iterate(stmt, show_one_statement, (void *)sep);
 550 }
 551
 552 static void show_one_expression(struct expression *expr, void *sep, int flags)
 553 {
 554         show_expression(expr);
 555         if (!(flags & ITERATE_LAST))
 556                 printf("%s", (const char *)sep);
 557 }
 558
 559 void show_expression_list(struct expression_list *list, const char *sep)
 560 {
 561         expression_iterate(list, show_one_expression, (void *)sep);
 562 }
 563
 564 static int show_call_expression(struct expression *expr)
 565 {
 566         struct symbol *direct;
 567         struct expression *arg, *fn;
 568         int fncall, retval;
 569         int framesize;
 570
 571         if (!expr->ctype) {
 572                 warn(expr->pos, "\tcall with no type!");
 573                 return 0;
 574         }
 575
 576         framesize = 0;
 577         FOR_EACH_PTR_REVERSE(expr->args, arg) {
 578                 int new = show_expression(arg);
 579                 int size = arg->ctype->bit_size;
 580                 printf("\tpush.%d\t\tv%d\n", size, new);
 581                 framesize += size >> 3;
 582         } END_FOR_EACH_PTR_REVERSE;
 583
 584         fn = expr->fn;
 585
 586         /* Remove dereference, if any */
 587         direct = NULL;
 588         if (fn->type == EXPR_PREOP) {
 589                 if (fn->unop->type == EXPR_SYMBOL) {
 590                         struct symbol *sym = fn->unop->symbol;
 591                         if (sym->ctype.base_type->type == SYM_FN)
 592                                 direct = sym;
 593                 }
 594         }
 595         if (direct) {
 596                 printf("\tcall\t\t%s\n", show_ident(direct->ident));
 597         } else {
 598                 fncall = show_expression(fn);
 599                 printf("\tcall\t\t*v%d\n", fncall);
 600         }
 601         if (framesize)
 602                 printf("\tadd.%d\t\tvSP,vSP,$%d\n", BITS_IN_POINTER, framesize);
 603
 604         retval = new_pseudo();
 605         printf("\tmov.%d\t\tv%d,retval\n", expr->ctype->bit_size, retval);
 606         return retval;
 607 }
 608
 609 static int show_binop(struct expression *expr)
 610 {
 611         int left = show_expression(expr->left);
 612         int right = show_expression(expr->right);
 613         int new = new_pseudo();
 614         const char *opname;
 615         static const char *name[] = {
 616                 ['+'] = "add", ['-'] = "sub",
 617                 ['*'] = "mul", ['/'] = "div",
 618                 ['%'] = "mod", ['&'] = "and",
 619                 ['|'] = "lor", ['^'] = "xor"
 620         };
 621         unsigned int op = expr->op;
 622
 623         opname = show_special(op);
 624         if (op < sizeof(name)/sizeof(*name))
 625                 opname = name[op];
 626         printf("\t%s.%d\t\tv%d,v%d,v%d\n", opname,
 627                 expr->ctype->bit_size,
 628                 new, left, right);
 629         return new;
 630 }
 631
 632 static int show_regular_preop(struct expression *expr)
 633 {
 634         int target = show_expression(expr->unop);
 635         int new = new_pseudo();
 636         static const char *name[] = {
 637                 ['!'] = "nonzero", ['-'] = "neg",
 638                 ['~'] = "not",
 639         };
 640         unsigned int op = expr->op;
 641         const char *opname;
 642
 643         opname = show_special(op);
 644         if (op < sizeof(name)/sizeof(*name))
 645                 opname = name[op];
 646         printf("\t%s.%d\t\tv%d,v%d\n", opname, expr->ctype->bit_size, new, target);
 647         return new;
 648 }
 649
 650 /*
 651  * FIXME! Not all accesses are memory loads. We should
 652  * check what kind of symbol is behind the dereference.
 653  */
 654 static int show_address_gen(struct expression *expr)
 655 {
 656         if (expr->type == EXPR_PREOP)
 657                 return show_expression(expr->unop);
 658         return show_expression(expr->address);
 659 }
 660
 661 static int show_load_gen(int bits, struct expression *expr, int addr)
 662 {
 663         int new = new_pseudo();
 664
 665         printf("\tld.%d\t\tv%d,[v%d]\n", bits, new, addr);
 666         if (expr->type == EXPR_PREOP)
 667                 return new;
 668
 669         /* bitfield load! */
 670         if (expr->bitpos)
 671                 printf("\tshr.%d\t\tv%d,v%d,$%d\n", bits, new, new, expr->bitpos);
 672         printf("\tandi.%d\t\tv%d,v%d,$%llu\n", bits, new, new, (1ULL << expr->nrbits)-1);
 673         return new;
 674 }
 675
 676 static void show_store_gen(int bits, int value, struct expression *expr, int addr)
 677 {
 678         /* FIXME!!! Bitfield store! */
 679         printf("\tst.%d\t\tv%d,[v%d]\n", bits, value, addr);
 680 }
 681
 682 static int show_assignment(struct expression *expr)
 683 {
 684         struct expression *target = expr->left;
 685         int val, addr, bits;
 686
 687         if (!expr->ctype)
 688                 return 0;
 689
 690         bits = expr->ctype->bit_size;
 691         val = show_expression(expr->right);
 692         addr = show_address_gen(target);
 693         show_store_gen(bits, val, target, addr);
 694         return val;
 695 }
 696
 697 static int show_return_stmt(struct statement *stmt)
 698 {
 699         struct expression *expr = stmt->ret_value;
 700         struct symbol *target = stmt->ret_target;
 701
 702         if (expr && expr->ctype) {
 703                 int val = show_expression(expr);
 704                 int bits = expr->ctype->bit_size;
 705                 int addr = show_symbol_expr(target);
 706                 show_store_gen(bits, val, NULL, addr);
 707         }
 708         printf("\tret\t\t(%p)\n", target);
 709         return 0;
 710 }
 711
 712 static int show_initialization(struct symbol *sym, struct expression *expr)
 713 {
 714         int val, addr, bits;
 715
 716         if (!expr->ctype)
 717                 return 0;
 718
 719         bits = expr->ctype->bit_size;
 720         val = show_expression(expr);
 721         addr = show_symbol_expr(sym);
 722         // FIXME! The "target" expression is for bitfield store information.
 723         // Leave it NULL, which works fine.
 724         show_store_gen(bits, val, NULL, addr);
 725         return 0;
 726 }
 727
 728 static int show_access(struct expression *expr)
 729 {
 730         int addr = show_address_gen(expr);
 731         return show_load_gen(expr->ctype->bit_size, expr, addr);
 732 }
 733
 734 static int show_inc_dec(struct expression *expr, int postop)
 735 {
 736         int addr = show_address_gen(expr->unop);
 737         int retval, new;
 738         const char *opname = expr->op == SPECIAL_INCREMENT ? "add" : "sub";
 739         int bits = expr->ctype->bit_size;
 740
 741         retval = show_load_gen(bits, expr->unop, addr);
 742         new = retval;
 743         if (postop)
 744                 new = new_pseudo();
 745         printf("\t%s.%d\t\tv%d,v%d,$1\n", opname, bits, new, retval);
 746         show_store_gen(bits, new, expr->unop, addr);
 747         return retval;
 748 }
 749
 750 static int show_preop(struct expression *expr)
 751 {
 752         /*
 753          * '*' is an lvalue access, and is fundamentally different
 754          * from an arithmetic operation. Maybe it should have an
 755          * expression type of its own..
 756          */
 757         if (expr->op == '*')
 758                 return show_access(expr);
 759         if (expr->op == SPECIAL_INCREMENT || expr->op == SPECIAL_DECREMENT)
 760                 return show_inc_dec(expr, 0);
 761         return show_regular_preop(expr);
 762 }
 763
 764 static int show_postop(struct expression *expr)
 765 {
 766         return show_inc_dec(expr, 1);
 767 }
 768
 769 static int show_symbol_expr(struct symbol *sym)
 770 {
 771         int new = new_pseudo();
 772
 773         if (sym->ctype.modifiers & (MOD_TOPLEVEL | MOD_EXTERN | MOD_STATIC)) {
 774                 printf("\tmovi.%d\t\tv%d,$%s\n", BITS_IN_POINTER, new, show_ident(sym->ident));
 775                 return new;
 776         }
 777         if (sym->ctype.modifiers & MOD_ADDRESSABLE) {
 778                 printf("\taddi.%d\t\tv%d,vFP,$%lld\n", BITS_IN_POINTER, new, sym->value);
 779                 return new;
 780         }
 781         printf("\taddi.%d\t\tv%d,vFP,$offsetof(%s:%p)\n", BITS_IN_POINTER, new, show_ident(sym->ident), sym);
 782         return new;
 783 }
 784
 785 static int show_symbol_init(struct symbol *sym)
 786 {
 787         struct expression *expr = sym->initializer;
 788
 789         if (expr) {
 790                 int val, addr, bits;
 791
 792                 bits = expr->ctype->bit_size;
 793                 val = show_expression(expr);
 794                 addr = show_symbol_expr(sym);
 795                 show_store_gen(bits, val, NULL, addr);
 796         }
 797         return 0;
 798 }
 799
 800 static int type_is_signed(struct symbol *sym)
 801 {
 802         if (sym->type == SYM_NODE)
 803                 sym = sym->ctype.base_type;
 804         if (sym->type == SYM_PTR)
 805                 return 0;
 806         return !(sym->ctype.modifiers & MOD_UNSIGNED);
 807 }
 808
 809 static int show_cast_expr(struct expression *expr)
 810 {
 811         struct symbol *old_type, *new_type;
 812         int op = show_expression(expr->cast_expression);
 813         int oldbits, newbits;
 814         int new, is_signed;
 815
 816         old_type = expr->cast_expression->ctype;
 817         new_type = expr->cast_type;
 818
 819         oldbits = old_type->bit_size;
 820         newbits = new_type->bit_size;
 821         if (oldbits >= newbits)
 822                 return op;
 823         new = new_pseudo();
 824         is_signed = type_is_signed(old_type);
 825         if (is_signed) {
 826                 printf("\tsext%d.%d\tv%d,v%d\n", oldbits, newbits, new, op);
 827         } else {
 828                 printf("\tandl.%d\t\tv%d,v%d,$%lu\n", newbits, new, op, (1UL << oldbits)-1);
 829         }
 830         return new;
 831 }
 832
 833 static int show_value(struct expression *expr)
 834 {
 835         int new = new_pseudo();
 836         unsigned long long value = expr->value;
 837
 838         printf("\tmovi.%d\t\tv%d,$%llu\n", expr->ctype->bit_size, new, value);
 839         return new;
 840 }
 841
 842 static int show_string_expr(struct expression *expr)
 843 {
 844         int new = new_pseudo();
 845
 846         printf("\tmovi.%d\t\tv%d,&%s\n", BITS_IN_POINTER, new, show_string(expr->string));
 847         return new;
 848 }
 849
 850 static int show_bitfield_expr(struct expression *expr)
 851 {
 852         return show_access(expr);
 853 }
 854
 855 int show_label_expr(struct expression *expr)
 856 {
 857         int new = new_pseudo();
 858         printf("\tmovi.%d\t\tv%d,.L%p\n",BITS_IN_POINTER, new, expr->label_symbol);
 859         return new;
 860 }
 861
 862 static int show_conditional_expr(struct expression *expr)
 863 {
 864         int cond = show_expression(expr->conditional);
 865         int true = show_expression(expr->cond_true);
 866         int false = show_expression(expr->cond_false);
 867         int new = new_pseudo();
 868
 869         if (!true)
 870                 true = cond;
 871         printf("[v%d]\tcmov.%d\t\tv%d,v%d,v%d\n", cond, expr->ctype->bit_size, new, true, false);
 872         return new;
 873 }
 874
 875 static int show_statement_expr(struct expression *expr)
 876 {
 877         return show_statement(expr->statement);
 878 }
 879
 880 static int show_position_expr(struct expression *expr, struct symbol *base)
 881 {
 882         int new = show_expression(expr->init_expr);
 883         struct symbol *ctype = expr->init_sym;
 884
 885         printf("\tinsert v%d at [%d:%d] of %s\n", new,
 886                 expr->init_offset, ctype->bit_offset,
 887                 show_ident(base->ident));
 888         return 0;
 889 }
 890
 891 static int show_initializer_expr(struct expression *expr, struct symbol *ctype)
 892 {
 893         struct expression *entry;
 894
 895         FOR_EACH_PTR(expr->expr_list, entry) {
 896                 // Nested initializers have their positions already
 897                 // recursively calculated - just output them too
 898                 if (entry->type == EXPR_INITIALIZER) {
 899                         show_initializer_expr(entry, ctype);
 900                         continue;
 901                 }
 902
 903                 // Ignore initializer indexes and identifiers - the
 904                 // evaluator has taken them into account
 905                 if (entry->type == EXPR_IDENTIFIER || entry->type == EXPR_INDEX)
 906                         continue;
 907                 if (entry->type == EXPR_POS) {
 908                         show_position_expr(entry, ctype);
 909                         continue;
 910                 }
 911                 show_initialization(ctype, entry);
 912         } END_FOR_EACH_PTR;
 913         return 0;
 914 }
 915
 916 int show_symbol_expr_init(struct symbol *sym)
 917 {
 918         struct expression *expr = sym->initializer;
 919
 920         if (expr)
 921                 show_expression(expr);
 922         return show_symbol_expr(sym);
 923 }
 924
 925 /*
 926  * Print out an expression. Return the pseudo that contains the
 927  * variable.
 928  */
 929 int show_expression(struct expression *expr)
 930 {
 931         if (!expr)
 932                 return 0;
 933
 934         if (!expr->ctype) {
 935                 struct position *pos = &expr->pos;
 936                 printf("\tno type at %s:%d:%d\n",
 937                         input_streams[pos->stream].name,
 938                         pos->line, pos->pos);
 939                 return 0;
 940         }
 941
 942         switch (expr->type) {
 943         case EXPR_CALL:
 944                 return show_call_expression(expr);
 945
 946         case EXPR_ASSIGNMENT:
 947                 return show_assignment(expr);
 948
 949         case EXPR_BINOP:
 950         case EXPR_COMMA:
 951         case EXPR_COMPARE:
 952         case EXPR_LOGICAL:
 953                 return show_binop(expr);
 954         case EXPR_PREOP:
 955                 return show_preop(expr);
 956         case EXPR_POSTOP:
 957                 return show_postop(expr);
 958         case EXPR_SYMBOL:
 959                 return show_symbol_expr(expr->symbol);
 960         case EXPR_DEREF:
 961         case EXPR_SIZEOF:
 962                 warn(expr->pos, "invalid expression after evaluation");
 963                 return 0;
 964         case EXPR_CAST:
 965                 return show_cast_expr(expr);
 966         case EXPR_VALUE:
 967                 return show_value(expr);
 968         case EXPR_STRING:
 969                 return show_string_expr(expr);
 970         case EXPR_BITFIELD:
 971                 return show_bitfield_expr(expr);
 972         case EXPR_INITIALIZER:
 973                 return show_initializer_expr(expr, expr->ctype);
 974         case EXPR_CONDITIONAL:
 975                 return show_conditional_expr(expr);
 976         case EXPR_STATEMENT:
 977                 return show_statement_expr(expr);
 978         case EXPR_LABEL:
 979                 return show_label_expr(expr);
 980
 981         // None of these should exist as direct expressions: they are only
 982         // valid as sub-expressions of initializers.
 983         case EXPR_POS:
 984                 warn(expr->pos, "unable to show plain initializer position expression");
 985                 return 0;
 986         case EXPR_IDENTIFIER:
 987                 warn(expr->pos, "unable to show identifier expression");
 988                 return 0;
 989         case EXPR_INDEX:
 990                 warn(expr->pos, "unable to show index expression");
 991                 return 0;
 992         case EXPR_TYPE:
 993                 warn(expr->pos, "unable to show type expression");
 994                 return 0;
 995         }
 996         return 0;
 997 }