nsz Git - libfirm/blob - ir/be/begnuas.c

   1 /*
   2  * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
   3  *
   4  * This file is part of libFirm.
   5  *
   6  * This file may be distributed and/or modified under the terms of the
   7  * GNU General Public License version 2 as published by the Free Software
   8  * Foundation and appearing in the file LICENSE.GPL included in the
   9  * packaging of this file.
  10  *
  11  * Licensees holding valid libFirm Professional Edition licenses may use
  12  * this file in accordance with the libFirm Commercial License.
  13  * Agreement provided with the Software.
  14  *
  15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
  16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE.
  18  */
  19
  20 /**
  21  * @file
  22  * @brief       Dumps global variables and constants as gas assembler.
  23  * @author      Christian Wuerdig, Matthias Braun
  24  * @date        04.11.2005
  25  * @version     $Id$
  26  */
  27 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include "begnuas.h"
  32
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <ctype.h>
  36 #include <assert.h>
  37
  38 #include "obst.h"
  39 #include "tv.h"
  40 #include "irnode.h"
  41 #include "irprog.h"
  42 #include "pdeq.h"
  43 #include "entity_t.h"
  44 #include "error.h"
  45
  46 #include "be_t.h"
  47 #include "beemitter.h"
  48 #include "be_dbgout.h"
  49
  50 /** by default, we generate assembler code for the Linux gas */
  51 be_gas_flavour_t be_gas_flavour = GAS_FLAVOUR_ELF;
  52
  53 static be_gas_section_t current_section = (be_gas_section_t) -1;
  54
  55 /**
  56  * Return the pseudo-instruction to be issued for a section switch
  57  * depending on the current flavour.
  58  *
  59  * @param section  the section to switch to
  60  *
  61  * @return  the pseudo-instruction
  62  */
  63 static const char *get_section_name(be_gas_section_t section) {
  64         static const char *text[GAS_FLAVOUR_LAST+1][GAS_SECTION_LAST+1] = {
  65                 { /* GAS_FLAVOUR_ELF */
  66                         ".section\t.text",
  67                         ".section\t.data",
  68                         ".section\t.rodata",
  69                         ".section\t.bss",
  70                         ".section\t.tbss,\"awT\",@nobits",
  71                         ".section\t.ctors,\"aw\",@progbits",
  72                         NULL, /* no cstring section */
  73                         NULL,
  74                         NULL
  75                 },
  76                 { /* GAS_FLAVOUR_MINGW */
  77                         ".section\t.text",
  78                         ".section\t.data",
  79                         ".section .rdata,\"dr\"",
  80                         ".section\t.bss",
  81                         ".section\t.tbss,\"awT\",@nobits",
  82                         ".section\t.ctors,\"aw\",@progbits",
  83                         NULL,
  84                         NULL,
  85                         NULL
  86                 },
  87                 { /* GAS_FLAVOUR_YASM */
  88                         ".section\t.text",
  89                         ".section\t.data",
  90                         ".section\t.rodata",
  91                         ".section\t.bss",
  92                         ".section\t.tbss,\"awT\",@nobits",
  93                         ".section\t.ctors,\"aw\",@progbits",
  94                         NULL,
  95                         NULL,
  96                         NULL
  97                 },
  98                 { /* GAS_FLAVOUR_MACH_O */
  99                         ".text",
 100                         ".data",
 101                         ".const",
 102                         ".data",
 103                         NULL,             /* TLS is not supported on Mach-O */
 104                         ".mod_init_func",
 105                         ".cstring",
 106                         ".section\t__IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_instructions,5",
 107                         ".section\t__IMPORT,__pointers,non_lazy_symbol_pointers"
 108                 }
 109         };
 110
 111         assert((int) be_gas_flavour >= 0 && be_gas_flavour <= GAS_FLAVOUR_LAST);
 112         assert((int) section >= 0 && section <= GAS_SECTION_LAST);
 113         return text[be_gas_flavour][section];
 114 }
 115
 116 void be_gas_emit_switch_section(be_gas_section_t section) {
 117         if(current_section == section)
 118                 return;
 119
 120         be_emit_char('\t');
 121         be_emit_string(get_section_name(section));
 122         be_emit_char('\n');
 123         be_emit_write_line();
 124         current_section = section;
 125 }
 126
 127 void be_gas_emit_function_prolog(ir_entity *entity, unsigned alignment)
 128 {
 129         const char *name = get_entity_ld_name(entity);
 130         const char *fill_byte = "";
 131         unsigned maximum_skip;
 132
 133         be_gas_emit_switch_section(GAS_SECTION_TEXT);
 134
 135         /* write the begin line (used by scripts processing the assembler... */
 136         be_emit_write_line();
 137         be_emit_cstring("# -- Begin  ");
 138         be_emit_string(name);
 139         be_emit_char('\n');
 140         be_emit_write_line();
 141
 142         /* gcc fills space between function with 0x90, no idea if this is needed */
 143         if(be_gas_flavour == GAS_FLAVOUR_MACH_O) {
 144                 fill_byte = "0x90";
 145         }
 146
 147         maximum_skip = (1 << alignment) - 1;
 148         be_emit_cstring("\t.p2align ");
 149         be_emit_irprintf("%u,%s,%u\n", alignment, fill_byte, maximum_skip);
 150         be_emit_write_line();
 151
 152         if (get_entity_visibility(entity) == visibility_external_visible) {
 153                 be_emit_cstring(".globl ");
 154                 be_emit_string(name);
 155                 be_emit_char('\n');
 156                 be_emit_write_line();
 157         }
 158
 159         switch (be_gas_flavour) {
 160         case GAS_FLAVOUR_ELF:
 161                 be_emit_cstring("\t.type\t");
 162                 be_emit_string(name);
 163                 be_emit_cstring(", @function\n");
 164                 be_emit_write_line();
 165                 break;
 166         case GAS_FLAVOUR_MINGW:
 167                 be_emit_cstring("\t.def\t");
 168                 be_emit_string(name);
 169                 be_emit_cstring(";\t.scl\t2;\t.type\t32;\t.endef\n");
 170                 be_emit_write_line();
 171                 break;
 172         case GAS_FLAVOUR_MACH_O:
 173         case GAS_FLAVOUR_YASM:
 174                 break;
 175         }
 176         be_emit_string(name);
 177         be_emit_cstring(":\n");
 178         be_emit_write_line();
 179 }
 180
 181 void be_gas_emit_function_epilog(ir_entity *entity)
 182 {
 183         const char *name = get_entity_ld_name(entity);
 184
 185         if (be_gas_flavour == GAS_FLAVOUR_ELF) {
 186                 be_emit_cstring("\t.size\t");
 187                 be_emit_string(name);
 188                 be_emit_cstring(", .-");
 189                 be_emit_string(name);
 190                 be_emit_char('\n');
 191                 be_emit_write_line();
 192         }
 193
 194         be_emit_cstring("# -- End  ");
 195         be_emit_string(name);
 196         be_emit_char('\n');
 197         be_emit_write_line();
 198 }
 199
 200 /**
 201  * An environment containing all needed dumper data.
 202  * Currently we create the file completely in memory first, then
 203  * write it to the disk. This is an artifact from the old C-generating backend
 204  * and even there NOT needed. So we might change it in the future.
 205  */
 206 typedef struct _be_gas_decl_env {
 207         const be_main_env_t *main_env; /**< The main backend environment, used for it's debug handle. */
 208         be_gas_section_t     section;
 209         waitq               *worklist;           /**< A worklist we use to place not yet handled entities on. */
 210 } be_gas_decl_env_t;
 211
 212 /************************************************************************/
 213
 214 /**
 215  * Output a tarval.
 216  *
 217  * @param tv     the tarval
 218  * @param bytes  the width of the tarvals value in bytes
 219  */
 220 static void dump_arith_tarval(tarval *tv, int bytes)
 221 {
 222         switch (bytes) {
 223         case 1:
 224                 be_emit_irprintf("0x%02x", get_tarval_sub_bits(tv, 0));
 225                 break;
 226
 227         case 2:
 228                 be_emit_irprintf("0x%02x%02x", get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 229                 break;
 230
 231         case 4:
 232                 be_emit_irprintf("0x%02x%02x%02x%02x",
 233                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 234                 break;
 235
 236         case 8:
 237                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x",
 238                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6), get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
 239                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 240                 break;
 241
 242         case 10:
 243         case 12:
 244                 break;
 245
 246         case 16:
 247                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x"
 248                                                "%02x%02x%02x%02x%02x%02x%02x%02x",
 249                         get_tarval_sub_bits(tv, 15), get_tarval_sub_bits(tv, 16),
 250                         get_tarval_sub_bits(tv, 13), get_tarval_sub_bits(tv, 12),
 251                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 252                         get_tarval_sub_bits(tv, 9), get_tarval_sub_bits(tv, 8),
 253                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6),
 254                         get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
 255                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2),
 256                         get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 257                 break;
 258
 259
 260         default:
 261                 fprintf(stderr, "Try to dump an tarval with %d bytes\n", bytes);
 262                 assert(0);
 263         }
 264 }
 265
 266 /**
 267  * Return the label prefix for labeled blocks.
 268  */
 269 const char *be_gas_label_prefix(void) {
 270         return ".LG";
 271 }
 272
 273 /**
 274  * Dump a label.
 275  */
 276 static void dump_label(ir_label_t label) {
 277         be_emit_irprintf("%s%ld", be_gas_label_prefix(), label);
 278 }
 279
 280 /**
 281  * Return the tarval of an atomic initializer.
 282  *
 283  * @param init  a node representing the initializer (on the const code irg)
 284  *
 285  * @return the tarval
 286  */
 287 static tarval *get_atomic_init_tv(ir_node *init)
 288 {
 289         for (;;) {
 290                 ir_mode *mode = get_irn_mode(init);
 291
 292                 switch (get_irn_opcode(init)) {
 293
 294                 case iro_Cast:
 295                         init = get_Cast_op(init);
 296                         continue;
 297
 298                 case iro_Conv:
 299                         init = get_Conv_op(init);
 300                         continue;
 301
 302                 case iro_Const:
 303                         return get_Const_tarval(init);
 304
 305                 case iro_SymConst:
 306                         switch (get_SymConst_kind(init)) {
 307                         case symconst_type_size:
 308                                 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(init)), mode);
 309
 310                         case symconst_type_align:
 311                                 return new_tarval_from_long(get_type_alignment_bytes(get_SymConst_type(init)), mode);
 312
 313                         case symconst_ofs_ent:
 314                                 return new_tarval_from_long(get_entity_offset(get_SymConst_entity(init)), mode);
 315
 316                         case symconst_enum_const:
 317                                 return get_enumeration_value(get_SymConst_enum(init));
 318
 319                         case symconst_label:
 320                                 return NULL;
 321
 322                         default:
 323                                 return NULL;
 324                         }
 325
 326                 default:
 327                         return NULL;
 328                 }
 329         }
 330 }
 331
 332 /**
 333  * Dump an atomic value.
 334  *
 335  * @param env   the gas output environment
 336  * @param init  a node representing the atomic value (on the const code irg)
 337  */
 338 static void do_dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 339 {
 340         ir_mode *mode = get_irn_mode(init);
 341         int bytes     = get_mode_size_bytes(mode);
 342         tarval *tv;
 343         ir_label_t label;
 344         ir_entity *ent;
 345
 346         init = skip_Id(init);
 347
 348         switch (get_irn_opcode(init)) {
 349         case iro_Cast:
 350                 do_dump_atomic_init(env, get_Cast_op(init));
 351                 return;
 352
 353         case iro_Conv:
 354                 do_dump_atomic_init(env, get_Conv_op(init));
 355                 return;
 356
 357         case iro_Const:
 358                 tv = get_Const_tarval(init);
 359
 360                 /* it's a arithmetic value */
 361                 dump_arith_tarval(tv, bytes);
 362                 return;
 363
 364         case iro_SymConst:
 365                 switch (get_SymConst_kind(init)) {
 366                 case symconst_addr_name:
 367                         be_emit_ident(get_SymConst_name(init));
 368                         break;
 369
 370                 case symconst_addr_ent:
 371                         ent = get_SymConst_entity(init);
 372                         if(!is_entity_backend_marked(ent)) {
 373                                 waitq_put(env->worklist, ent);
 374                                 set_entity_backend_marked(ent, 1);
 375                         }
 376                         be_emit_ident(get_entity_ld_ident(ent));
 377                         break;
 378
 379                 case symconst_ofs_ent:
 380                         ent = get_SymConst_entity(init);
 381 #if 0       /* not needed, is it? */
 382                         if(!is_entity_backend_marked(ent)) {
 383                                 waitq_put(env->worklist, ent);
 384                                 set_entity_backend_marked(ent, 1);
 385                         }
 386 #endif
 387                         be_emit_irprintf("%d", get_entity_offset(ent));
 388                         break;
 389
 390                 case symconst_type_size:
 391                         be_emit_irprintf("%u", get_type_size_bytes(get_SymConst_type(init)));
 392                         break;
 393
 394                 case symconst_type_align:
 395                         be_emit_irprintf("%u", get_type_alignment_bytes(get_SymConst_type(init)));
 396                         break;
 397
 398                 case symconst_enum_const:
 399                         tv = get_enumeration_value(get_SymConst_enum(init));
 400                         dump_arith_tarval(tv, bytes);
 401                         break;
 402
 403                 case symconst_label:
 404                         label = get_SymConst_label(init);
 405                         dump_label(label);
 406                         break;
 407
 408                 default:
 409                         assert(!"dump_atomic_init(): don't know how to init from this SymConst");
 410                 }
 411                 return;
 412
 413                 case iro_Add:
 414                         do_dump_atomic_init(env, get_Add_left(init));
 415                         be_emit_cstring(" + ");
 416                         do_dump_atomic_init(env, get_Add_right(init));
 417                         return;
 418
 419                 case iro_Sub:
 420                         do_dump_atomic_init(env, get_Sub_left(init));
 421                         be_emit_cstring(" - ");
 422                         do_dump_atomic_init(env, get_Sub_right(init));
 423                         return;
 424
 425                 case iro_Mul:
 426                         do_dump_atomic_init(env, get_Mul_left(init));
 427                         be_emit_cstring(" * ");
 428                         do_dump_atomic_init(env, get_Mul_right(init));
 429                         return;
 430
 431                 default:
 432                         assert(0 && "dump_atomic_init(): unknown IR-node");
 433         }
 434 }
 435
 436 /**
 437  * Dumps the type for given size (.byte, .long, ...)
 438  *
 439  * @param size  the size in bytes
 440  */
 441 static void dump_size_type(size_t size) {
 442         switch (size) {
 443         case 1:
 444                 be_emit_cstring("\t.byte\t");
 445                 break;
 446
 447         case 2:
 448                 be_emit_cstring("\t.word\t");
 449                 break;
 450
 451         case 4:
 452                 be_emit_cstring("\t.long\t");
 453                 break;
 454
 455         case 8:
 456                 be_emit_cstring("\t.quad\t");
 457                 break;
 458
 459         case 10:
 460         case 12:
 461                 /* handled in arith */
 462                 break;
 463
 464         case 16:
 465                 be_emit_cstring("\t.octa\t");
 466                 break;
 467
 468         default:
 469                 panic("Try to dump a type with %u bytes\n", (unsigned) size);
 470         }
 471 }
 472
 473 /**
 474  * Emit an atomic value.
 475  *
 476  * @param env   the gas output environment
 477  * @param init  a node representing the atomic value (on the const code irg)
 478  */
 479 static void dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 480 {
 481         ir_mode *mode = get_irn_mode(init);
 482         int bytes     = get_mode_size_bytes(mode);
 483
 484         dump_size_type(bytes);
 485         do_dump_atomic_init(env, init);
 486         be_emit_char('\n');
 487         be_emit_write_line();
 488 }
 489
 490 /************************************************************************/
 491 /* Routines to dump global variables                                    */
 492 /************************************************************************/
 493
 494 static int initializer_is_string_const(const ir_initializer_t *initializer)
 495 {
 496         size_t i, len;
 497         int found_printable = 0;
 498
 499         if(initializer->kind != IR_INITIALIZER_COMPOUND)
 500                 return 0;
 501
 502         len = initializer->compound.n_initializers;
 503         if (len < 1)
 504                 return 0;
 505         for(i = 0; i < len; ++i) {
 506                 int               c;
 507                 tarval           *tv;
 508                 ir_mode          *mode;
 509                 ir_initializer_t *sub_initializer
 510                         = initializer->compound.initializers[i];
 511
 512                 if(sub_initializer->kind != IR_INITIALIZER_TARVAL)
 513                         return 0;
 514
 515                 tv   = sub_initializer->tarval.value;
 516                 mode = get_tarval_mode(tv);
 517
 518                 if (!mode_is_int(mode)
 519                                 || get_mode_size_bits(mode) != get_mode_size_bits(mode_Bs))
 520                         return 0;
 521
 522                 c = get_tarval_long(tv);
 523                 if (isgraph(c) || isspace(c))
 524                         found_printable = 1;
 525                 else if(c != 0)
 526                         return 0;
 527
 528                 if (i == len - 1 && c != '\0')
 529                         return 0;
 530         }
 531
 532         return found_printable;
 533 }
 534
 535 /**
 536  * Determine if an entity is a string constant
 537  * @param ent The entity
 538  * @return 1 if it is a string constant, 0 otherwise
 539  */
 540 static int ent_is_string_const(ir_entity *ent)
 541 {
 542         ir_type *type, *element_type;
 543         ir_mode *mode;
 544         int i, c, n;
 545         int found_printable = 0;
 546
 547         type = get_entity_type(ent);
 548
 549         /* if it's an array */
 550         if (!is_Array_type(type))
 551                 return 0;
 552
 553         element_type = get_array_element_type(type);
 554
 555         /* and the array's element type is primitive */
 556         if (!is_Primitive_type(element_type))
 557                 return 0;
 558
 559         /* and the mode of the element type is an int of
 560          * the same size as the byte mode */
 561         mode = get_type_mode(element_type);
 562         if (!mode_is_int(mode)
 563                 || get_mode_size_bits(mode) != get_mode_size_bits(mode_Bs))
 564                 return 0;
 565
 566         if(ent->has_initializer) {
 567                 /* TODO */
 568                 return 0;
 569         } else {
 570                 /* if it contains only printable chars and a 0 at the end */
 571                 n = get_compound_ent_n_values(ent);
 572                 for (i = 0; i < n; ++i) {
 573                         ir_node *irn = get_compound_ent_value(ent, i);
 574                         if (! is_Const(irn))
 575                                 return 0;
 576
 577                         c = (int) get_tarval_long(get_Const_tarval(irn));
 578
 579                         if (isgraph(c) || isspace(c))
 580                                 found_printable = 1;
 581                         else if(c != 0)
 582                                 return 0;
 583
 584                         if (i == n - 1 && c != '\0')
 585                                 return 0;
 586                 }
 587         }
 588
 589         /* then we can emit it as a string constant */
 590         return found_printable;
 591 }
 592
 593 /**
 594  * Dump a string constant.
 595  * No checks are made!!
 596  *
 597  * @param ent  The entity to dump.
 598  */
 599 static void dump_string_cst(ir_entity *ent)
 600 {
 601         int      i, len;
 602         ir_type *type;
 603         int      type_size;
 604         int      remaining_space;
 605
 606         len = get_compound_ent_n_values(ent);
 607         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
 608                 be_emit_cstring("\t.ascii \"");
 609         } else {
 610                 be_emit_cstring("\t.string \"");
 611                 len -= 1;
 612         }
 613
 614         for (i = 0; i < len; ++i) {
 615                 ir_node *irn;
 616                 int c;
 617
 618                 irn = get_compound_ent_value(ent, i);
 619                 c = (int) get_tarval_long(get_Const_tarval(irn));
 620
 621                 switch (c) {
 622                 case '"' : be_emit_cstring("\\\""); break;
 623                 case '\n': be_emit_cstring("\\n"); break;
 624                 case '\r': be_emit_cstring("\\r"); break;
 625                 case '\t': be_emit_cstring("\\t"); break;
 626                 case '\\': be_emit_cstring("\\\\"); break;
 627                 default  :
 628                         if (isprint(c))
 629                                 be_emit_char(c);
 630                         else
 631                                 be_emit_irprintf("\\%o", c);
 632                         break;
 633                 }
 634         }
 635         be_emit_cstring("\"\n");
 636         be_emit_write_line();
 637
 638         type            = get_entity_type(ent);
 639         type_size       = get_type_size_bytes(type);
 640         remaining_space = type_size - len;
 641         assert(remaining_space >= 0);
 642         if(remaining_space > 0) {
 643                 be_emit_irprintf("\t.skip\t%d\n", remaining_space);
 644         }
 645 }
 646
 647 static void dump_string_initializer(const ir_initializer_t *initializer)
 648 {
 649         size_t i, len;
 650
 651         len = initializer->compound.n_initializers;
 652         if(be_gas_flavour == GAS_FLAVOUR_MACH_O) {
 653                 be_emit_cstring("\t.ascii \"");
 654         } else {
 655                 be_emit_cstring("\t.string \"");
 656                 len -= 1;
 657         }
 658
 659         for(i = 0; i < len; ++i) {
 660                 const ir_initializer_t *sub_initializer
 661                         = get_initializer_compound_value(initializer, i);
 662
 663                 tarval *tv = get_initializer_tarval_value(sub_initializer);
 664                 int     c  = get_tarval_long(tv);
 665
 666                 switch (c) {
 667                 case '"' : be_emit_cstring("\\\""); break;
 668                 case '\n': be_emit_cstring("\\n"); break;
 669                 case '\r': be_emit_cstring("\\r"); break;
 670                 case '\t': be_emit_cstring("\\t"); break;
 671                 case '\\': be_emit_cstring("\\\\"); break;
 672                 default  :
 673                         if (isprint(c))
 674                                 be_emit_char(c);
 675                         else
 676                                 be_emit_irprintf("\\%o", c);
 677                         break;
 678                 }
 679         }
 680         be_emit_cstring("\"\n");
 681         be_emit_write_line();
 682 }
 683
 684 enum normal_or_bitfield_kind {
 685         NORMAL = 0,
 686         TARVAL,
 687         BITFIELD
 688 };
 689
 690 typedef struct {
 691         enum normal_or_bitfield_kind kind;
 692         union {
 693                 ir_node       *value;
 694                 tarval        *tarval;
 695                 unsigned char  bf_val;
 696         } v;
 697 } normal_or_bitfield;
 698
 699 static int is_type_variable_size(ir_type *type)
 700 {
 701         (void) type;
 702         /* TODO */
 703         return 0;
 704 }
 705
 706 static size_t get_initializer_size(const ir_initializer_t *initializer,
 707                                    ir_type *type)
 708 {
 709         switch(get_initializer_kind(initializer)) {
 710         case IR_INITIALIZER_TARVAL: {
 711                 assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type));
 712                 return get_type_size_bytes(type);
 713         }
 714         case IR_INITIALIZER_CONST:
 715         case IR_INITIALIZER_NULL:
 716                 return get_type_size_bytes(type);
 717         case IR_INITIALIZER_COMPOUND: {
 718                 if(!is_type_variable_size(type)) {
 719                         return get_type_size_bytes(type);
 720                 } else {
 721                         unsigned n_entries
 722                                 = get_initializer_compound_n_entries(initializer);
 723                         unsigned i;
 724                         unsigned initializer_size = get_type_size_bytes(type);
 725                         for(i = 0; i < n_entries; ++i) {
 726                                 ir_entity *entity = get_compound_member(type, i);
 727                                 ir_type   *type   = get_entity_type(entity);
 728
 729                                 const ir_initializer_t *sub_initializer
 730                                         = get_initializer_compound_value(initializer, i);
 731
 732                                 unsigned offset = get_entity_offset(entity);
 733                                 unsigned size   = get_initializer_size(sub_initializer, type);
 734
 735                                 if(offset + size > initializer_size) {
 736                                         initializer_size = offset + size;
 737                                 }
 738                         }
 739                         return initializer_size;
 740                 }
 741         }
 742         }
 743
 744         panic("found invalid initializer");
 745 }
 746
 747 #ifndef NDEBUG
 748 static normal_or_bitfield *glob_vals;
 749 static size_t              max_vals;
 750 #endif
 751
 752 static void dump_bitfield(normal_or_bitfield *vals, size_t offset_bits,
 753                           const ir_initializer_t *initializer, ir_type *type)
 754 {
 755         unsigned char  last_bits = 0;
 756         ir_mode       *mode      = get_type_mode(type);
 757         tarval        *tv        = NULL;
 758         unsigned char  curr_bits;
 759         int            value_len;
 760         int            j;
 761
 762         switch(get_initializer_kind(initializer)) {
 763         case IR_INITIALIZER_NULL:
 764                 return;
 765         case IR_INITIALIZER_TARVAL:
 766                 tv = get_initializer_tarval_value(initializer);
 767                 break;
 768         case IR_INITIALIZER_CONST: {
 769                 ir_node *node = get_initializer_const_value(initializer);
 770                 if(!is_Const(node)) {
 771                         panic("bitfield initializer not a Const node");
 772                 }
 773                 tv = get_Const_tarval(node);
 774                 break;
 775         }
 776         case IR_INITIALIZER_COMPOUND:
 777                 panic("bitfield initializer is compound");
 778         }
 779         if (tv == NULL) {
 780                 panic("Couldn't get numeric value for bitfield initializer\n");
 781         }
 782
 783         /* normalize offset */
 784         vals        += offset_bits >> 3;
 785         offset_bits &= 7;
 786         value_len    = get_mode_size_bits(mode);
 787
 788         /* combine bits with existing bits */
 789         for (j = 0; value_len + (int) offset_bits > 0; ++j) {
 790                 assert((size_t) (vals - glob_vals) + j < max_vals);
 791                 assert(vals[j].kind == BITFIELD ||
 792                                 (vals[j].kind == NORMAL && vals[j].v.value == NULL));
 793                 vals[j].kind = BITFIELD;
 794                 curr_bits    = get_tarval_sub_bits(tv, j);
 795                 vals[j].v.bf_val
 796                         |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
 797                 value_len -= 8;
 798                 last_bits = curr_bits;
 799         }
 800 }
 801
 802 static void dump_ir_initializer(normal_or_bitfield *vals,
 803                                 const ir_initializer_t *initializer,
 804                                 ir_type *type)
 805 {
 806         assert((size_t) (vals - glob_vals) < max_vals);
 807
 808         switch(get_initializer_kind(initializer)) {
 809         case IR_INITIALIZER_NULL:
 810                 return;
 811         case IR_INITIALIZER_TARVAL: {
 812                 size_t i;
 813
 814                 assert(vals->kind != BITFIELD);
 815                 vals->kind     = TARVAL;
 816                 vals->v.tarval = get_initializer_tarval_value(initializer);
 817                 assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval));
 818                 for(i = 1; i < get_type_size_bytes(type); ++i) {
 819                         vals[i].kind    = NORMAL;
 820                         vals[i].v.value = NULL;
 821                 }
 822                 return;
 823         }
 824         case IR_INITIALIZER_CONST: {
 825                 size_t i;
 826
 827                 assert(vals->kind != BITFIELD);
 828                 vals->kind    = NORMAL;
 829                 vals->v.value = get_initializer_const_value(initializer);
 830                 for(i = 1; i < get_type_size_bytes(type); ++i) {
 831                         vals[i].kind    = NORMAL;
 832                         vals[i].v.value = NULL;
 833                 }
 834                 return;
 835         }
 836         case IR_INITIALIZER_COMPOUND: {
 837                 size_t i = 0;
 838                 size_t n = get_initializer_compound_n_entries(initializer);
 839
 840                 if(is_Array_type(type)) {
 841                         ir_type *element_type = get_array_element_type(type);
 842                         size_t   skip         = get_type_size_bytes(element_type);
 843                         size_t   alignment    = get_type_alignment_bytes(element_type);
 844                         size_t   misalign     = skip % alignment;
 845                         if(misalign != 0) {
 846                                 skip += alignment - misalign;
 847                         }
 848
 849                         for(i = 0; i < n; ++i) {
 850                                 ir_initializer_t *sub_initializer
 851                                         = get_initializer_compound_value(initializer, i);
 852
 853                                 dump_ir_initializer(vals, sub_initializer, element_type);
 854
 855                                 vals += skip;
 856                         }
 857                 } else {
 858                         size_t n_members, i;
 859                         assert(is_compound_type(type));
 860                         n_members = get_compound_n_members(type);
 861                         for(i = 0; i < n_members; ++i) {
 862                                 ir_entity        *member    = get_compound_member(type, i);
 863                                 size_t            offset    = get_entity_offset(member);
 864                                 ir_type          *subtype   = get_entity_type(member);
 865                                 ir_mode          *mode      = get_type_mode(subtype);
 866                                 ir_initializer_t *sub_initializer;
 867
 868                                 assert(i < get_initializer_compound_n_entries(initializer));
 869                                 sub_initializer
 870                                         = get_initializer_compound_value(initializer, i);
 871
 872                                 if(mode != NULL) {
 873                                         size_t offset_bits
 874                                                 = get_entity_offset_bits_remainder(member);
 875                                         size_t value_len   = get_mode_size_bits(mode);
 876
 877                                         if(offset_bits != 0 ||
 878                                                 (value_len != 8 && value_len != 16 && value_len != 32
 879                                                  && value_len != 64)) {
 880                                                 dump_bitfield(&vals[offset], offset_bits,
 881                                                               sub_initializer, subtype);
 882                                                 continue;
 883                                         }
 884                                 }
 885
 886                                 dump_ir_initializer(&vals[offset], sub_initializer, subtype);
 887                         }
 888                 }
 889
 890                 return;
 891         }
 892         }
 893         panic("invalid ir_initializer kind found");
 894 }
 895
 896 static void dump_initializer(be_gas_decl_env_t *env, ir_entity *entity)
 897 {
 898         const ir_initializer_t *initializer = entity->attr.initializer;
 899         ir_type                *type;
 900         normal_or_bitfield     *vals;
 901         size_t                  size;
 902         size_t                  k;
 903
 904         if(initializer_is_string_const(initializer)) {
 905                 dump_string_initializer(initializer);
 906                 return;
 907         }
 908
 909         type = get_entity_type(entity);
 910         size = get_initializer_size(initializer, type);
 911
 912         if (size == 0)
 913                 return;
 914
 915         /*
 916          * In the worst case, every initializer allocates one byte.
 917          * Moreover, initializer might be big, do not allocate on stack.
 918          */
 919         vals = xcalloc(size, sizeof(vals[0]));
 920
 921 #ifndef NDEBUG
 922         glob_vals = vals;
 923         max_vals  = size;
 924 #endif
 925
 926         dump_ir_initializer(vals, initializer, type);
 927
 928         /* now write values sorted */
 929         for (k = 0; k < size; ) {
 930                 int space = 0, skip = 0;
 931                 if (vals[k].kind == NORMAL) {
 932                         if(vals[k].v.value != NULL) {
 933                                 dump_atomic_init(env, vals[k].v.value);
 934                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
 935                         } else {
 936                                 space = 1;
 937                         }
 938                 } else if(vals[k].kind == TARVAL) {
 939                         tarval *tv   = vals[k].v.tarval;
 940                         size_t  size = get_mode_size_bytes(get_tarval_mode(tv));
 941
 942                         assert(tv != NULL);
 943
 944                         skip = size - 1;
 945                         dump_size_type(size);
 946                         dump_arith_tarval(tv, size);
 947                         be_emit_char('\n');
 948                         be_emit_write_line();
 949                 } else {
 950                         assert(vals[k].kind == BITFIELD);
 951                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
 952                         be_emit_write_line();
 953                 }
 954
 955                 ++k;
 956                 while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
 957                         ++space;
 958                         ++k;
 959                 }
 960                 space -= skip;
 961                 assert(space >= 0);
 962
 963                 /* a gap */
 964                 if (space > 0) {
 965                         be_emit_irprintf("\t.skip\t%d\n", space);
 966                         be_emit_write_line();
 967                 }
 968         }
 969         xfree(vals);
 970 }
 971
 972 /**
 973  * Dump an initializer for a compound entity.
 974  */
 975 static void dump_compound_init(be_gas_decl_env_t *env, ir_entity *ent)
 976 {
 977         normal_or_bitfield *vals;
 978         int i, j, n;
 979         unsigned k, last_ofs;
 980
 981         if(ent->has_initializer) {
 982                 dump_initializer(env, ent);
 983                 return;
 984         }
 985
 986         n = get_compound_ent_n_values(ent);
 987
 988         /* Find the initializer size. Sorrily gcc support a nasty feature:
 989            The last field of a compound may be a flexible array. This allows
 990            initializers bigger than the type size. */
 991         last_ofs = get_type_size_bytes(get_entity_type(ent));
 992         for (i = 0; i < n; ++i) {
 993                 unsigned offset         = get_compound_ent_value_offset_bytes(ent, i);
 994                 unsigned bits_remainder = get_compound_ent_value_offset_bit_remainder(ent, i);
 995                 ir_node  *value         = get_compound_ent_value(ent, i);
 996                 unsigned value_len      = get_mode_size_bits(get_irn_mode(value));
 997
 998                 offset += (value_len + bits_remainder + 7) >> 3;
 999
1000                 if (offset > last_ofs) {
1001                         last_ofs = offset;
1002                 }
1003         }
1004
1005         /*
1006          * In the worst case, every initializer allocates one byte.
1007          * Moreover, initializer might be big, do not allocate on stack.
1008          */
1009         vals = xcalloc(last_ofs, sizeof(vals[0]));
1010
1011         /* collect the values and store them at the offsets */
1012         for (i = 0; i < n; ++i) {
1013                 unsigned offset      = get_compound_ent_value_offset_bytes(ent, i);
1014                 int      offset_bits = get_compound_ent_value_offset_bit_remainder(ent, i);
1015                 ir_node  *value      = get_compound_ent_value(ent, i);
1016                 int      value_len   = get_mode_size_bits(get_irn_mode(value));
1017
1018                 assert(offset_bits >= 0);
1019
1020                 if (offset_bits != 0 ||
1021                         (value_len != 8 && value_len != 16 && value_len != 32 && value_len != 64)) {
1022                         tarval *tv = get_atomic_init_tv(value);
1023                         unsigned char curr_bits, last_bits = 0;
1024                         if (tv == NULL) {
1025                                 panic("Couldn't get numeric value for bitfield initializer '%s'\n",
1026                                       get_entity_ld_name(ent));
1027                         }
1028                         /* normalize offset */
1029                         offset += offset_bits >> 3;
1030                         offset_bits &= 7;
1031
1032                         for (j = 0; value_len + offset_bits > 0; ++j) {
1033                                 assert(offset + j < last_ofs);
1034                                 assert(vals[offset + j].kind == BITFIELD || vals[offset + j].v.value == NULL);
1035                                 vals[offset + j].kind = BITFIELD;
1036                                 curr_bits = get_tarval_sub_bits(tv, j);
1037                                 vals[offset + j].v.bf_val |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
1038                                 value_len -= 8;
1039                                 last_bits = curr_bits;
1040                         }
1041                 } else {
1042                         int i;
1043
1044                         assert(offset < last_ofs);
1045                         assert(vals[offset].kind == NORMAL);
1046                         for (i = 1; i < value_len / 8; ++i) {
1047                                 assert(vals[offset + i].v.value == NULL);
1048                         }
1049                         vals[offset].v.value = value;
1050                 }
1051         }
1052
1053         /* now write them sorted */
1054         for (k = 0; k < last_ofs; ) {
1055                 int space = 0, skip = 0;
1056                 if (vals[k].kind == NORMAL) {
1057                         if(vals[k].v.value != NULL) {
1058                                 dump_atomic_init(env, vals[k].v.value);
1059                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
1060                         } else {
1061                                 space = 1;
1062                         }
1063                 } else {
1064                         assert(vals[k].kind == BITFIELD);
1065                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1066                 }
1067
1068                 ++k;
1069                 while (k < last_ofs && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1070                         ++space;
1071                         ++k;
1072                 }
1073                 space -= skip;
1074                 assert(space >= 0);
1075
1076                 /* a gap */
1077                 if (space > 0) {
1078                         be_emit_irprintf("\t.skip\t%d\n", space);
1079                         be_emit_write_line();
1080                 }
1081         }
1082         xfree(vals);
1083 }
1084
1085 static void emit_align(unsigned alignment)
1086 {
1087         if (!is_po2(alignment))
1088                 panic("alignment not a power of 2");
1089
1090         be_emit_irprintf(".p2align\t%u\n", log2_floor(alignment));
1091         be_emit_write_line();
1092 }
1093
1094 /**
1095  * Dump a global entity.
1096  *
1097  * @param env           the gas output environment
1098  * @param ent           the entity to be dumped
1099  */
1100 static void dump_global(be_gas_decl_env_t *env, ir_entity *ent)
1101 {
1102         ir_type          *type           = get_entity_type(ent);
1103         ident            *ld_ident       = get_entity_ld_ident(ent);
1104         unsigned          align          = get_type_alignment_bytes(type);
1105         int               emit_as_common = 0;
1106         be_gas_section_t  section        = env->section;
1107         ir_variability    variability    = get_entity_variability(ent);
1108         ir_visibility     visibility     = get_entity_visibility(ent);
1109
1110         if (is_Method_type(type) && section != GAS_SECTION_PIC_TRAMPOLINES) {
1111                 return;
1112         }
1113
1114         if (section != (be_gas_section_t) -1) {
1115                 emit_as_common = 0;
1116         } else if (variability == variability_constant) {
1117                 /* a constant entity, put it on the rdata */
1118                 section = GAS_SECTION_RODATA;
1119                 if (be_gas_flavour == GAS_FLAVOUR_MACH_O
1120                                 && ent_is_string_const(ent)) {
1121                         section = GAS_SECTION_CSTRING;
1122                 }
1123         } else if (variability == variability_uninitialized) {
1124                 /* uninitialized entity put it in bss segment */
1125                 section = GAS_SECTION_COMMON;
1126                 if (visibility != visibility_local)
1127                         emit_as_common = 1;
1128         } else {
1129                 section = GAS_SECTION_DATA;
1130         }
1131
1132         if(!emit_as_common) {
1133                 be_gas_emit_switch_section(section);
1134         }
1135
1136         be_dbg_variable(ent);
1137
1138         /* global or not global */
1139         if (visibility == visibility_external_visible && !emit_as_common) {
1140                 be_emit_cstring(".globl\t");
1141                 be_emit_ident(ld_ident);
1142                 be_emit_char('\n');
1143                 be_emit_write_line();
1144         } else if(visibility == visibility_external_allocated) {
1145                 be_emit_cstring(".globl\t");
1146                 be_emit_ident(ld_ident);
1147                 be_emit_char('\n');
1148                 be_emit_write_line();
1149                 /* we can return now... */
1150                 return;
1151         }
1152         /* alignment */
1153         if (align > 1 && !emit_as_common && section != GAS_SECTION_PIC_TRAMPOLINES
1154                         && section != GAS_SECTION_PIC_SYMBOLS) {
1155                 emit_align(align);
1156         }
1157
1158         if (!emit_as_common) {
1159                 be_emit_ident(ld_ident);
1160                 be_emit_cstring(":\n");
1161                 be_emit_write_line();
1162         }
1163
1164         if (variability == variability_uninitialized) {
1165                 if (emit_as_common) {
1166                         switch (be_gas_flavour) {
1167                         case GAS_FLAVOUR_ELF:
1168                         case GAS_FLAVOUR_MACH_O:
1169                         case GAS_FLAVOUR_YASM:
1170                                 be_emit_irprintf("\t.comm %s,%u,%u\n",
1171                                         get_id_str(ld_ident), get_type_size_bytes(type), align);
1172                                 be_emit_write_line();
1173                                 break;
1174                         case GAS_FLAVOUR_MINGW:
1175                                 be_emit_irprintf("\t.comm %s,%u # %u\n",
1176                                         get_id_str(ld_ident), get_type_size_bytes(type), align);
1177                                 be_emit_write_line();
1178                                 break;
1179                         }
1180                 } else if (section == GAS_SECTION_PIC_TRAMPOLINES) {
1181                         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
1182                                 be_emit_cstring("\t.indirect_symbol ");
1183                                 be_emit_ident(get_entity_ident(ent));
1184                                 be_emit_char('\n');
1185                                 be_emit_write_line();
1186                                 be_emit_cstring("\thlt ; hlt ; hlt ; hlt ; hlt\n");
1187                                 be_emit_write_line();
1188                         } else {
1189                                 panic("PIC trampolines not yet supported in this gas mode");
1190                         }
1191                 } else {
1192                         be_emit_irprintf("\t.space %u\n", get_type_size_bytes(type));
1193                         be_emit_write_line();
1194                 }
1195         } else {
1196                 if (is_atomic_entity(ent)) {
1197                         dump_atomic_init(env, get_atomic_ent_value(ent));
1198                 } else {
1199                         /* sort_compound_ent_values(ent); */
1200
1201                         switch (get_type_tpop_code(get_entity_type(ent))) {
1202                         case tpo_array:
1203                                 if (ent_is_string_const(ent))
1204                                         dump_string_cst(ent);
1205                                 else
1206                                         dump_compound_init(env, ent);
1207                                 break;
1208                         case tpo_struct:
1209                         case tpo_class:
1210                         case tpo_union:
1211                                 dump_compound_init(env, ent);
1212                                 break;
1213                         default:
1214                                 assert(0);
1215                         }
1216                 }
1217         }
1218 }
1219
1220 /**
1221  * Dumps declarations of global variables and the initialization code.
1222  *
1223  * @param gt                a global like type, either the global or the TLS one
1224  * @param env               an environment
1225  * @param only_emit_marked  if non-zero, external allocated entities that do not have
1226  *                          its visited flag set are ignored
1227  */
1228 static void be_gas_dump_globals(ir_type *gt, be_gas_decl_env_t *env,
1229                                 int only_emit_marked)
1230 {
1231         int i, n = get_compound_n_members(gt);
1232         waitq *worklist = new_waitq();
1233
1234         if (only_emit_marked) {
1235                 for (i = 0; i < n; i++) {
1236                         ir_entity *ent = get_compound_member(gt, i);
1237                         if (is_entity_backend_marked(ent) ||
1238                             get_entity_visibility(ent) != visibility_external_allocated) {
1239                                 waitq_put(worklist, ent);
1240                                 set_entity_backend_marked(ent, 1);
1241                         }
1242                 }
1243         } else {
1244                 for (i = 0; i < n; i++) {
1245                         ir_entity *ent = get_compound_member(gt, i);
1246                         set_entity_backend_marked(ent, 1);
1247                         waitq_put(worklist, ent);
1248                 }
1249         }
1250
1251         env->worklist = worklist;
1252
1253         while (!waitq_empty(worklist)) {
1254                 ir_entity *ent = waitq_get(worklist);
1255
1256                 dump_global(env, ent);
1257         }
1258
1259         del_waitq(worklist);
1260         env->worklist = NULL;
1261 }
1262
1263 /************************************************************************/
1264
1265 /* Generate all entities. */
1266 void be_gas_emit_decls(const be_main_env_t *main_env,
1267                        int only_emit_marked_entities)
1268 {
1269         be_gas_decl_env_t env;
1270         memset(&env, 0, sizeof(env));
1271
1272         env.main_env = main_env;
1273
1274         /* dump global type */
1275         env.section = (be_gas_section_t) -1;
1276         be_gas_dump_globals(get_glob_type(), &env, only_emit_marked_entities);
1277         env.section = GAS_SECTION_TLS;
1278         be_gas_dump_globals(get_tls_type(), &env, only_emit_marked_entities);
1279         env.section = GAS_SECTION_CTOR;
1280         be_gas_dump_globals(get_constructors_type(), &env,
1281                             only_emit_marked_entities);
1282         env.section = GAS_SECTION_PIC_SYMBOLS;
1283         be_gas_dump_globals(main_env->pic_symbols_type, &env,
1284                             only_emit_marked_entities);
1285
1286         if (get_compound_n_members(main_env->pic_trampolines_type) > 0) {
1287                 env.section = GAS_SECTION_PIC_TRAMPOLINES;
1288                 be_gas_dump_globals(main_env->pic_trampolines_type, &env,
1289                                     only_emit_marked_entities);
1290                 if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
1291                         be_emit_cstring("\t.subsections_via_symbols\n");
1292                         be_emit_write_line();
1293                 }
1294         }
1295 }