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 #include "config.h"
  28
  29 #include "begnuas.h"
  30
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <ctype.h>
  34 #include <assert.h>
  35
  36 #include "obst.h"
  37 #include "tv.h"
  38 #include "irnode.h"
  39 #include "irprog.h"
  40 #include "entity_t.h"
  41 #include "error.h"
  42 #include "util.h"
  43
  44 #include "be_t.h"
  45 #include "beemitter.h"
  46 #include "be_dbgout.h"
  47
  48 /** by default, we generate assembler code for the Linux gas */
  49 object_file_format_t  be_gas_object_file_format = OBJECT_FILE_FORMAT_ELF;
  50 bool                  be_gas_emit_types         = true;
  51 char                  be_gas_elf_type_char      = '@';
  52
  53 static be_gas_section_t current_section = (be_gas_section_t) -1;
  54
  55 /**
  56  * An environment containing all needed dumper data.
  57  * Currently we create the file completely in memory first, then
  58  * write it to the disk. This is an artifact from the old C-generating backend
  59  * and even there NOT needed. So we might change it in the future.
  60  */
  61 typedef struct be_gas_decl_env {
  62         be_gas_section_t     section;
  63         const be_main_env_t *main_env;
  64 } be_gas_decl_env_t;
  65
  66 static void emit_section_macho(be_gas_section_t section)
  67 {
  68         be_gas_section_t  base  = section & GAS_SECTION_TYPE_MASK;
  69         be_gas_section_t  flags = section & ~GAS_SECTION_TYPE_MASK;
  70         const char       *name;
  71
  72         if (current_section == section)
  73                 return;
  74         current_section = section;
  75
  76         /* shortforms */
  77         if (flags == 0) {
  78                 switch (base) {
  79                 case GAS_SECTION_TEXT:            name = "text";          break;
  80                 case GAS_SECTION_DATA:            name = "data";          break;
  81                 case GAS_SECTION_RODATA:          name = "const";         break;
  82                 case GAS_SECTION_BSS:             name = "data";          break;
  83                 case GAS_SECTION_CONSTRUCTORS:    name = "mod_init_func"; break;
  84                 case GAS_SECTION_DESTRUCTORS:     name = "mod_term_func"; break;
  85                 case GAS_SECTION_PIC_TRAMPOLINES: name = "section\t__IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_instructions,5"; break;
  86                 case GAS_SECTION_PIC_SYMBOLS:     name = "section\t__IMPORT,__pointers,non_lazy_symbol_pointers"; break;
  87                 case GAS_SECTION_CSTRING:         name = "cstring";       break;
  88                 default: panic("unsupported scetion type 0x%X", section);
  89                 }
  90                 be_emit_irprintf("\t.%s\n", name);
  91                 be_emit_write_line();
  92         } else if (flags & GAS_SECTION_FLAG_COMDAT) {
  93                 switch (base) {
  94                 case GAS_SECTION_TEXT:            name = "section __TEXT,__textcoal_nt,coalesced,pure_instructions"; break;
  95                 case GAS_SECTION_BSS:
  96                 case GAS_SECTION_DATA:            name = "section __DATA,__datacoal_nt,coalesced"; break;
  97                 case GAS_SECTION_RODATA:          name = "section __TEXT,__const_coal,coalesced"; break;
  98                 case GAS_SECTION_CSTRING:         name = "section __TEXT,__const_coal,coalesced"; break;
  99                 default: panic("unsupported scetion type 0x%X", section);
 100                 }
 101         } else {
 102                 panic("unsupported section type 0x%X\n", section);
 103         }
 104 }
 105
 106 static void emit_section_sparc(be_gas_section_t section, const ir_entity *entity)
 107 {
 108         be_gas_section_t base = section & GAS_SECTION_TYPE_MASK;
 109         be_gas_section_t flags = section & ~GAS_SECTION_TYPE_MASK;
 110         static const char *const basename[] = {
 111                 "text", "data", "rodata", "bss", "ctors", "dtors"
 112         };
 113
 114         if (current_section == section && !(section & GAS_SECTION_FLAG_COMDAT))
 115                 return;
 116         current_section = section;
 117
 118         be_emit_cstring("\t.section\t\".");
 119
 120         /* Part1: section-name */
 121         if (flags & GAS_SECTION_FLAG_TLS)
 122                 be_emit_char('t');
 123         assert(base < (be_gas_section_t)ARRAY_SIZE(basename));
 124         be_emit_string(basename[base]);
 125
 126         if (flags & GAS_SECTION_FLAG_COMDAT) {
 127                 be_emit_char('.');
 128                 be_gas_emit_entity(entity);
 129         }
 130         be_emit_char('"');
 131
 132         /* for the simple sections we're done here */
 133         if (flags == 0)
 134                 goto end;
 135
 136         be_emit_cstring(",#alloc");
 137
 138         switch (base) {
 139         case GAS_SECTION_TEXT: be_emit_cstring(",#execinstr"); break;
 140         case GAS_SECTION_DATA:
 141         case GAS_SECTION_BSS:  be_emit_cstring(",#write"); break;
 142         default:
 143                 /* nothing */
 144                 break;
 145         }
 146         if (flags & GAS_SECTION_FLAG_TLS) {
 147                 be_emit_cstring(",#tls");
 148         }
 149
 150 end:
 151         be_emit_char('\n');
 152         be_emit_write_line();
 153 }
 154
 155 static void emit_section(be_gas_section_t section, const ir_entity *entity)
 156 {
 157         be_gas_section_t base = section & GAS_SECTION_TYPE_MASK;
 158         be_gas_section_t flags = section & ~GAS_SECTION_TYPE_MASK;
 159         static const char *const basename[] = {
 160                 "text", "data", "rodata", "bss", "ctors", "dtors"
 161         };
 162         static const char *const type[] = {
 163                 "progbits", "progbits", "progbits", "nobits", "init_array", "fini_array"
 164         };
 165
 166         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 167                 emit_section_macho(section);
 168                 return;
 169         } else if(be_gas_object_file_format == OBJECT_FILE_FORMAT_ELF_SPARC) {
 170                 emit_section_sparc(section, entity);
 171                 return;
 172         }
 173
 174         if (current_section == section && !(section & GAS_SECTION_FLAG_COMDAT))
 175                 return;
 176         current_section = section;
 177
 178         /* shortforms */
 179         if (flags == 0) {
 180                 switch (base) {
 181                 case GAS_SECTION_TEXT:
 182                         be_emit_cstring("\t.text\n");
 183                         be_emit_write_line();
 184                         return;
 185                 case GAS_SECTION_DATA:
 186                         be_emit_cstring("\t.data\n");
 187                         be_emit_write_line();
 188                         return;
 189                 case GAS_SECTION_RODATA:
 190                         be_emit_cstring("\t.section\t.rodata\n");
 191                         be_emit_write_line();
 192                         return;
 193                 case GAS_SECTION_BSS:
 194                         be_emit_cstring("\t.bss\n");
 195                         be_emit_write_line();
 196                         return;
 197                 default:
 198                         break;
 199                 }
 200         }
 201
 202         assert(base < (be_gas_section_t) ARRAY_SIZE(basename));
 203         be_emit_cstring("\t.section\t.");
 204         /* section name */
 205         if (flags & GAS_SECTION_FLAG_TLS)
 206                 be_emit_char('t');
 207         be_emit_string(basename[base]);
 208         if (flags & GAS_SECTION_FLAG_COMDAT) {
 209                 be_emit_char('.');
 210                 be_gas_emit_entity(entity);
 211         }
 212
 213         /* section flags */
 214         be_emit_cstring(",\"");
 215         if (be_gas_object_file_format != OBJECT_FILE_FORMAT_COFF)
 216                 be_emit_char('a');
 217         if (base == GAS_SECTION_TEXT)
 218                 be_emit_char('x');
 219         if (base != GAS_SECTION_RODATA && base != GAS_SECTION_TEXT)
 220                 be_emit_char('w');
 221         if (flags & GAS_SECTION_FLAG_TLS)
 222                 be_emit_char('T');
 223         if (flags & GAS_SECTION_FLAG_COMDAT)
 224                 be_emit_char('G');
 225         /* section type */
 226         if (be_gas_object_file_format != OBJECT_FILE_FORMAT_COFF) {
 227                 be_emit_cstring("\",");
 228                 be_emit_char(be_gas_elf_type_char);
 229                 be_emit_string(type[base]);
 230         }
 231
 232         if (flags & GAS_SECTION_FLAG_COMDAT) {
 233                 be_emit_char(',');
 234                 be_gas_emit_entity(entity);
 235                 be_emit_cstring(",comdat");
 236         }
 237         be_emit_char('\n');
 238         be_emit_write_line();
 239 }
 240
 241
 242
 243 void be_gas_emit_switch_section(be_gas_section_t section)
 244 {
 245         /* you have to produce a switch_section call with entity manually
 246          * for comdat sections */
 247         assert( !(section & GAS_SECTION_FLAG_COMDAT));
 248
 249         emit_section(section, NULL);
 250 }
 251
 252 static ir_tarval *get_initializer_tarval(const ir_initializer_t *initializer)
 253 {
 254         if (initializer->kind == IR_INITIALIZER_TARVAL)
 255                 return initializer->tarval.value;
 256         if (initializer->kind == IR_INITIALIZER_CONST) {
 257                 ir_node *node = initializer->consti.value;
 258                 if (is_Const(node)) {
 259                         return get_Const_tarval(node);
 260                 }
 261         }
 262         return get_tarval_undefined();
 263 }
 264
 265 static int initializer_is_string_const(const ir_initializer_t *initializer)
 266 {
 267         size_t i, len;
 268         int found_printable = 0;
 269
 270         if (initializer->kind != IR_INITIALIZER_COMPOUND)
 271                 return 0;
 272
 273         len = initializer->compound.n_initializers;
 274         if (len < 1)
 275                 return 0;
 276         for (i = 0; i < len; ++i) {
 277                 int               c;
 278                 ir_tarval        *tv;
 279                 ir_mode          *mode;
 280                 ir_initializer_t *sub_initializer
 281                         = initializer->compound.initializers[i];
 282
 283                 tv = get_initializer_tarval(sub_initializer);
 284                 if (!tarval_is_constant(tv))
 285                         return 0;
 286
 287                 mode = get_tarval_mode(tv);
 288                 if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8)
 289                         return 0;
 290
 291                 c = get_tarval_long(tv);
 292                 if (isgraph(c) || isspace(c))
 293                         found_printable = 1;
 294                 else if (c != 0)
 295                         return 0;
 296
 297                 if (i == len - 1 && c != '\0')
 298                         return 0;
 299         }
 300
 301         return found_printable;
 302 }
 303
 304 static bool initializer_is_null(const ir_initializer_t *initializer)
 305 {
 306         switch (initializer->kind) {
 307         case IR_INITIALIZER_NULL:
 308                 return true;
 309         case IR_INITIALIZER_TARVAL: {
 310                 ir_tarval *tv = initializer->tarval.value;
 311                 return tarval_is_null(tv);
 312         }
 313         case IR_INITIALIZER_CONST: {
 314                 ir_node *value = initializer->consti.value;
 315                 if (!is_Const(value))
 316                         return false;
 317                 return is_Const_null(value);
 318         }
 319         case IR_INITIALIZER_COMPOUND: {
 320                 size_t i;
 321                 for (i = 0; i < initializer->compound.n_initializers; ++i) {
 322                         ir_initializer_t *subinitializer
 323                                 = initializer->compound.initializers[i];
 324                         if (!initializer_is_null(subinitializer))
 325                                 return false;
 326                 }
 327                 return true;
 328         }
 329         }
 330         panic("invalid initializer in initializer_is_null");
 331 }
 332
 333 /**
 334  * Determine if an entity is a string constant
 335  * @param ent The entity
 336  * @return 1 if it is a string constant, 0 otherwise
 337  */
 338 static int entity_is_string_const(const ir_entity *ent)
 339 {
 340         ir_type *type, *element_type;
 341         ir_mode *mode;
 342         int i, c, n;
 343
 344         type = get_entity_type(ent);
 345
 346         /* if it's an array */
 347         if (!is_Array_type(type))
 348                 return 0;
 349
 350         element_type = get_array_element_type(type);
 351
 352         /* and the array's element type is primitive */
 353         if (!is_Primitive_type(element_type))
 354                 return 0;
 355
 356         /* and the mode of the element type is an int of
 357          * the same size as the byte mode */
 358         mode = get_type_mode(element_type);
 359         if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8)
 360                 return 0;
 361
 362         if (ent->initializer != NULL) {
 363                 return initializer_is_string_const(ent->initializer);
 364         } else if (entity_has_compound_ent_values(ent)) {
 365                 int found_printable = 0;
 366                 /* if it contains only printable chars and a 0 at the end */
 367                 n = get_compound_ent_n_values(ent);
 368                 for (i = 0; i < n; ++i) {
 369                         ir_node *irn = get_compound_ent_value(ent, i);
 370                         if (! is_Const(irn))
 371                                 return 0;
 372
 373                         c = (int) get_tarval_long(get_Const_tarval(irn));
 374
 375                         if (isgraph(c) || isspace(c))
 376                                 found_printable = 1;
 377                         else if (c != 0)
 378                                 return 0;
 379
 380                         if (i == n - 1 && c != '\0')
 381                                 return 0;
 382                 }
 383                 return found_printable;
 384         }
 385
 386         return 0;
 387 }
 388
 389 static bool entity_is_null(const ir_entity *entity)
 390 {
 391         if (entity->initializer != NULL) {
 392                 return initializer_is_null(entity->initializer);
 393         } else if (entity_has_compound_ent_values(entity)) {
 394                 /* I'm too lazy to implement this case as compound graph paths will be
 395                  * remove anyway in the future */
 396                 return false;
 397         }
 398         /* uninitialized, NULL is fine */
 399         return true;
 400 }
 401
 402 static bool is_comdat(const ir_entity *entity)
 403 {
 404         ir_linkage linkage = get_entity_linkage(entity);
 405         return (linkage & IR_LINKAGE_MERGE)
 406                 && (linkage & IR_LINKAGE_GARBAGE_COLLECT);
 407 }
 408
 409 static be_gas_section_t determine_basic_section(const ir_entity *entity)
 410 {
 411         ir_linkage linkage;
 412
 413         if (is_method_entity(entity))
 414                 return GAS_SECTION_TEXT;
 415
 416         linkage = get_entity_linkage(entity);
 417         if (linkage & IR_LINKAGE_CONSTANT) {
 418                 /* mach-o is the only one with a cstring section */
 419                 if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O
 420                                 && entity_is_string_const(entity))
 421                         return GAS_SECTION_CSTRING;
 422
 423                 return GAS_SECTION_RODATA;
 424         }
 425         if (entity_is_null(entity))
 426                 return GAS_SECTION_BSS;
 427
 428         return GAS_SECTION_DATA;
 429 }
 430
 431 static be_gas_section_t determine_section(be_gas_decl_env_t *env,
 432                                           const ir_entity *entity)
 433 {
 434         ir_type *owner = get_entity_owner(entity);
 435
 436         if (owner == get_segment_type(IR_SEGMENT_GLOBAL)) {
 437                 be_gas_section_t section = determine_basic_section(entity);
 438                 if (is_comdat(entity))
 439                         section |= GAS_SECTION_FLAG_COMDAT;
 440                 return section;
 441         } else if (env != NULL && owner == env->main_env->pic_symbols_type) {
 442                 return GAS_SECTION_PIC_SYMBOLS;
 443         } else if (env != NULL && owner == env->main_env->pic_trampolines_type) {
 444                 return GAS_SECTION_PIC_TRAMPOLINES;
 445         } else if (owner == get_segment_type(IR_SEGMENT_CONSTRUCTORS)) {
 446                 return GAS_SECTION_CONSTRUCTORS;
 447         } else if (owner == get_segment_type(IR_SEGMENT_DESTRUCTORS)) {
 448                 return GAS_SECTION_DESTRUCTORS;
 449         } else if (owner == get_segment_type(IR_SEGMENT_THREAD_LOCAL)) {
 450                 be_gas_section_t section = determine_basic_section(entity);
 451                 if (is_comdat(entity))
 452                         section |= GAS_SECTION_FLAG_COMDAT;
 453
 454                 return section | GAS_SECTION_FLAG_TLS;
 455         }
 456
 457         /* the java frontend keeps some functions inside classes */
 458         if (is_Class_type(owner)) {
 459                 return determine_basic_section(entity);
 460         }
 461
 462         panic("Couldn't determine section for %+F?!?", entity);
 463 }
 464
 465 static void emit_weak(const ir_entity *entity)
 466 {
 467         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 468                 be_emit_cstring("\t.weak_reference ");
 469         } else {
 470                 be_emit_cstring("\t.weak ");
 471         }
 472         be_gas_emit_entity(entity);
 473         be_emit_char('\n');
 474         be_emit_write_line();
 475 }
 476
 477 static void emit_visibility(const ir_entity *entity)
 478 {
 479         ir_linkage linkage = get_entity_linkage(entity);
 480
 481         if (get_entity_linkage(entity) & IR_LINKAGE_WEAK) {
 482                 emit_weak(entity);
 483                 /* Note: .weak seems to imply .globl so no need to output .globl */
 484         } else if (get_entity_visibility(entity) == ir_visibility_default) {
 485                 be_emit_cstring(".globl ");
 486                 be_gas_emit_entity(entity);
 487                 be_emit_char('\n');
 488                 be_emit_write_line();
 489         }
 490
 491         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O
 492                         && (linkage & IR_LINKAGE_HIDDEN_USER)) {
 493                 be_emit_cstring("\t.no_dead_strip ");
 494                 be_gas_emit_entity(entity);
 495                 be_emit_char('\n');
 496                 be_emit_write_line();
 497         }
 498 }
 499
 500 void be_gas_emit_function_prolog(const ir_entity *entity, unsigned po2alignment)
 501 {
 502         be_gas_section_t section = determine_section(NULL, entity);
 503         emit_section(section, entity);
 504
 505         /* write the begin line (makes the life easier for scripts parsing the
 506          * assembler) */
 507         be_emit_write_line();
 508         be_emit_cstring("# -- Begin  ");
 509         be_gas_emit_entity(entity);
 510         be_emit_char('\n');
 511         be_emit_write_line();
 512
 513         if (po2alignment > 0) {
 514                 const char *fill_byte = "";
 515                 unsigned    maximum_skip = (1 << po2alignment) - 1;
 516                 /* gcc fills space between function with 0x90... */
 517                 if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 518                         fill_byte = "0x90";
 519                 }
 520                 be_emit_cstring("\t.p2align ");
 521                 be_emit_irprintf("%u,%s,%u\n", po2alignment, fill_byte, maximum_skip);
 522                 be_emit_write_line();
 523         }
 524         emit_visibility(entity);
 525
 526         switch (be_gas_object_file_format) {
 527         case OBJECT_FILE_FORMAT_ELF:
 528         case OBJECT_FILE_FORMAT_ELF_SPARC:
 529                 be_emit_cstring("\t.type\t");
 530                 be_gas_emit_entity(entity);
 531                 be_emit_cstring(", ");
 532                 be_emit_char(be_gas_elf_type_char);
 533                 be_emit_cstring("function\n");
 534                 be_emit_write_line();
 535                 break;
 536         case OBJECT_FILE_FORMAT_COFF:
 537                 be_emit_cstring("\t.def\t");
 538                 be_gas_emit_entity(entity);
 539                 be_emit_cstring(";");
 540                 if (get_entity_visibility(entity) == ir_visibility_local) {
 541                         be_emit_cstring("\t.scl\t3;");
 542                 } else {
 543                         be_emit_cstring("\t.scl\t2;");
 544                 }
 545                 be_emit_cstring("\t.type\t32;\t.endef\n");
 546                 be_emit_write_line();
 547                 break;
 548         case OBJECT_FILE_FORMAT_MACH_O:
 549                 break;
 550         }
 551         be_gas_emit_entity(entity);
 552         be_emit_cstring(":\n");
 553         be_emit_write_line();
 554 }
 555
 556 void be_gas_emit_function_epilog(const ir_entity *entity)
 557 {
 558         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_ELF) {
 559                 be_emit_cstring("\t.size\t");
 560                 be_gas_emit_entity(entity);
 561                 be_emit_cstring(", .-");
 562                 be_gas_emit_entity(entity);
 563                 be_emit_char('\n');
 564                 be_emit_write_line();
 565         }
 566
 567         be_emit_cstring("# -- End  ");
 568         be_gas_emit_entity(entity);
 569         be_emit_char('\n');
 570         be_emit_write_line();
 571 }
 572
 573 /**
 574  * Output a tarval.
 575  *
 576  * @param tv     the tarval
 577  * @param bytes  the width of the tarvals value in bytes
 578  */
 579 static void emit_arith_tarval(ir_tarval *tv, int bytes)
 580 {
 581         switch (bytes) {
 582         case 1:
 583                 be_emit_irprintf("0x%02x", get_tarval_sub_bits(tv, 0));
 584                 return;
 585
 586         case 2:
 587                 be_emit_irprintf("0x%02x%02x", get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 588                 return;
 589
 590         case 4:
 591                 be_emit_irprintf("0x%02x%02x%02x%02x",
 592                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 593                 return;
 594
 595         case 8:
 596                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x",
 597                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6), get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
 598                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 599                 return;
 600
 601         case 12:
 602                 /* Beware: Mixed endian output!  One little endian number emitted as
 603                  * three longs.  Each long initializer is written in big endian. */
 604                 be_emit_irprintf(
 605                         "\t.long\t0x%02x%02x%02x%02x\n"
 606                         "\t.long\t0x%02x%02x%02x%02x\n"
 607                         "\t.long\t0x%02x%02x%02x%02x",
 608                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
 609                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0),
 610                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
 611                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
 612                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 613                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8)
 614                 );
 615                 return;
 616
 617         case 16:
 618                 /* Beware: Mixed endian output!  One little endian number emitted as
 619                  * three longs.  Each long initializer is written in big endian. */
 620                 be_emit_irprintf(
 621                         "\t.long\t0x%02x%02x%02x%02x\n"
 622                         "\t.long\t0x%02x%02x%02x%02x\n"
 623                         "\t.long\t0x%02x%02x%02x%02x\n"
 624                         "\t.long\t0x%02x%02x%02x%02x",
 625                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
 626                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0),
 627                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
 628                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
 629                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 630                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8),
 631                         get_tarval_sub_bits(tv, 15), get_tarval_sub_bits(tv, 14),
 632                         get_tarval_sub_bits(tv, 13), get_tarval_sub_bits(tv, 12)
 633                 );
 634                 return;
 635         }
 636
 637         panic("Can't dump a tarval with %d bytes", bytes);
 638 }
 639
 640 /**
 641  * Return the label prefix for labeled instructions.
 642  */
 643 const char *be_gas_insn_label_prefix(void)
 644 {
 645         return ".LE";
 646 }
 647
 648 /**
 649  * Return the tarval of an atomic initializer.
 650  *
 651  * @param init  a node representing the initializer (on the const code irg)
 652  *
 653  * @return the tarval
 654  */
 655 static ir_tarval *get_atomic_init_tv(ir_node *init)
 656 {
 657         for (;;) {
 658                 ir_mode *mode = get_irn_mode(init);
 659
 660                 switch (get_irn_opcode(init)) {
 661
 662                 case iro_Cast:
 663                         init = get_Cast_op(init);
 664                         continue;
 665
 666                 case iro_Conv:
 667                         init = get_Conv_op(init);
 668                         continue;
 669
 670                 case iro_Const:
 671                         return get_Const_tarval(init);
 672
 673                 case iro_SymConst:
 674                         switch (get_SymConst_kind(init)) {
 675                         case symconst_type_size:
 676                                 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(init)), mode);
 677
 678                         case symconst_type_align:
 679                                 return new_tarval_from_long(get_type_alignment_bytes(get_SymConst_type(init)), mode);
 680
 681                         case symconst_ofs_ent:
 682                                 return new_tarval_from_long(get_entity_offset(get_SymConst_entity(init)), mode);
 683
 684                         case symconst_enum_const:
 685                                 return get_enumeration_value(get_SymConst_enum(init));
 686
 687                         default:
 688                                 return NULL;
 689                         }
 690
 691                 default:
 692                         return NULL;
 693                 }
 694         }
 695 }
 696
 697 /**
 698  * Dump an atomic value.
 699  *
 700  * @param env   the gas output environment
 701  * @param init  a node representing the atomic value (on the const code irg)
 702  */
 703 static void do_emit_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 704 {
 705         ir_mode *mode = get_irn_mode(init);
 706         int bytes     = get_mode_size_bytes(mode);
 707         ir_tarval *tv;
 708         ir_entity *ent;
 709
 710         init = skip_Id(init);
 711
 712         switch (get_irn_opcode(init)) {
 713         case iro_Cast:
 714                 do_emit_atomic_init(env, get_Cast_op(init));
 715                 return;
 716
 717         case iro_Conv:
 718                 do_emit_atomic_init(env, get_Conv_op(init));
 719                 return;
 720
 721         case iro_Const:
 722                 tv = get_Const_tarval(init);
 723
 724                 /* it's a arithmetic value */
 725                 emit_arith_tarval(tv, bytes);
 726                 return;
 727
 728         case iro_SymConst:
 729                 switch (get_SymConst_kind(init)) {
 730                 case symconst_addr_ent:
 731                         ent = get_SymConst_entity(init);
 732                         be_gas_emit_entity(ent);
 733                         break;
 734
 735                 case symconst_ofs_ent:
 736                         ent = get_SymConst_entity(init);
 737                         be_emit_irprintf("%d", get_entity_offset(ent));
 738                         break;
 739
 740                 case symconst_type_size:
 741                         be_emit_irprintf("%u", get_type_size_bytes(get_SymConst_type(init)));
 742                         break;
 743
 744                 case symconst_type_align:
 745                         be_emit_irprintf("%u", get_type_alignment_bytes(get_SymConst_type(init)));
 746                         break;
 747
 748                 case symconst_enum_const:
 749                         tv = get_enumeration_value(get_SymConst_enum(init));
 750                         emit_arith_tarval(tv, bytes);
 751                         break;
 752
 753                 default:
 754                         assert(!"emit_atomic_init(): don't know how to init from this SymConst");
 755                 }
 756                 return;
 757
 758         case iro_Add:
 759                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 760                         panic("Constant must be int or pointer for '+' to work");
 761                 }
 762                 do_emit_atomic_init(env, get_Add_left(init));
 763                 be_emit_cstring(" + ");
 764                 do_emit_atomic_init(env, get_Add_right(init));
 765                 return;
 766
 767         case iro_Sub:
 768                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 769                         panic("Constant must be int or pointer for '-' to work");
 770                 }
 771                 do_emit_atomic_init(env, get_Sub_left(init));
 772                 be_emit_cstring(" - ");
 773                 do_emit_atomic_init(env, get_Sub_right(init));
 774                 return;
 775
 776         case iro_Mul:
 777                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 778                         panic("Constant must be int or pointer for '*' to work");
 779                 }
 780                 do_emit_atomic_init(env, get_Mul_left(init));
 781                 be_emit_cstring(" * ");
 782                 do_emit_atomic_init(env, get_Mul_right(init));
 783                 return;
 784
 785         case iro_Unknown:
 786                 be_emit_cstring("0");
 787                 return;
 788
 789         default:
 790                 panic("emit_atomic_init(): unsupported IR-node %+F", init);
 791         }
 792 }
 793
 794 /**
 795  * Dumps the type for given size (.byte, .long, ...)
 796  *
 797  * @param size  the size in bytes
 798  */
 799 static void emit_size_type(size_t size)
 800 {
 801         switch (size) {
 802         case 1:
 803                 be_emit_cstring("\t.byte\t");
 804                 break;
 805
 806         case 2:
 807                 be_emit_cstring("\t.short\t");
 808                 break;
 809
 810         case 4:
 811                 be_emit_cstring("\t.long\t");
 812                 break;
 813
 814         case 8:
 815                 be_emit_cstring("\t.quad\t");
 816                 break;
 817
 818         case 10:
 819         case 12:
 820         case 16: /* Note: .octa does not work on mac */
 821                 /* handled in arith */
 822                 break;
 823
 824         default:
 825                 panic("Try to dump a type with %u bytes", (unsigned)size);
 826         }
 827 }
 828
 829 /**
 830  * Emit an atomic value.
 831  *
 832  * @param env   the gas output environment
 833  * @param init  a node representing the atomic value (on the const code irg)
 834  */
 835 static void emit_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 836 {
 837         ir_mode *mode = get_irn_mode(init);
 838         int bytes     = get_mode_size_bytes(mode);
 839
 840         emit_size_type(bytes);
 841         do_emit_atomic_init(env, init);
 842         be_emit_char('\n');
 843         be_emit_write_line();
 844 }
 845
 846 /**
 847  * Dump a string constant.
 848  * No checks are made!!
 849  *
 850  * @param ent  The entity to dump.
 851  */
 852 static void emit_string_cst(const ir_entity *ent)
 853 {
 854         int      i, len;
 855         int      output_len;
 856         ir_type *type;
 857         int      type_size;
 858         int      remaining_space;
 859
 860         len        = get_compound_ent_n_values(ent);
 861         output_len = len;
 862         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 863                 be_emit_cstring("\t.ascii \"");
 864         } else {
 865                 be_emit_cstring("\t.string \"");
 866                 output_len -= 1;
 867         }
 868
 869         for (i = 0; i < output_len; ++i) {
 870                 ir_node *irn;
 871                 int c;
 872
 873                 irn = get_compound_ent_value(ent, i);
 874                 c = (int) get_tarval_long(get_Const_tarval(irn));
 875
 876                 switch (c) {
 877                 case '"' : be_emit_cstring("\\\""); break;
 878                 case '\n': be_emit_cstring("\\n"); break;
 879                 case '\r': be_emit_cstring("\\r"); break;
 880                 case '\t': be_emit_cstring("\\t"); break;
 881                 case '\\': be_emit_cstring("\\\\"); break;
 882                 default  :
 883                         if (isprint(c))
 884                                 be_emit_char(c);
 885                         else
 886                                 be_emit_irprintf("\\%o", c);
 887                         break;
 888                 }
 889         }
 890         be_emit_cstring("\"\n");
 891         be_emit_write_line();
 892
 893         type            = get_entity_type(ent);
 894         type_size       = get_type_size_bytes(type);
 895         remaining_space = type_size - len;
 896         assert(remaining_space >= 0);
 897         if (remaining_space > 0) {
 898                 be_emit_irprintf("\t.space\t%d, 0\n", remaining_space);
 899         }
 900 }
 901
 902 static void emit_string_initializer(const ir_initializer_t *initializer)
 903 {
 904         size_t i, len;
 905
 906         len = initializer->compound.n_initializers;
 907         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 908                 be_emit_cstring("\t.ascii \"");
 909         } else {
 910                 be_emit_cstring("\t.string \"");
 911                 len -= 1;
 912         }
 913
 914         for (i = 0; i < len; ++i) {
 915                 const ir_initializer_t *sub_initializer
 916                         = get_initializer_compound_value(initializer, i);
 917
 918                 ir_tarval *tv = get_initializer_tarval(sub_initializer);
 919                 int        c  = get_tarval_long(tv);
 920
 921                 switch (c) {
 922                 case '"' : be_emit_cstring("\\\""); break;
 923                 case '\n': be_emit_cstring("\\n"); break;
 924                 case '\r': be_emit_cstring("\\r"); break;
 925                 case '\t': be_emit_cstring("\\t"); break;
 926                 case '\\': be_emit_cstring("\\\\"); break;
 927                 default  :
 928                         if (isprint(c))
 929                                 be_emit_char(c);
 930                         else
 931                                 be_emit_irprintf("\\%o", c);
 932                         break;
 933                 }
 934         }
 935         be_emit_cstring("\"\n");
 936         be_emit_write_line();
 937 }
 938
 939 enum normal_or_bitfield_kind {
 940         NORMAL = 0,
 941         TARVAL,
 942         BITFIELD
 943 };
 944
 945 typedef struct {
 946         enum normal_or_bitfield_kind kind;
 947         union {
 948                 ir_node       *value;
 949                 ir_tarval     *tarval;
 950                 unsigned char  bf_val;
 951         } v;
 952 } normal_or_bitfield;
 953
 954 static int is_type_variable_size(ir_type *type)
 955 {
 956         (void) type;
 957         /* TODO */
 958         return 0;
 959 }
 960
 961 static size_t get_initializer_size(const ir_initializer_t *initializer,
 962                                    ir_type *type)
 963 {
 964         switch (get_initializer_kind(initializer)) {
 965         case IR_INITIALIZER_TARVAL:
 966                 assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type));
 967                 return get_type_size_bytes(type);
 968         case IR_INITIALIZER_CONST:
 969         case IR_INITIALIZER_NULL:
 970                 return get_type_size_bytes(type);
 971         case IR_INITIALIZER_COMPOUND:
 972                 if (!is_type_variable_size(type)) {
 973                         return get_type_size_bytes(type);
 974                 } else {
 975                         unsigned n_entries
 976                                 = get_initializer_compound_n_entries(initializer);
 977                         unsigned i;
 978                         unsigned initializer_size = get_type_size_bytes(type);
 979                         for (i = 0; i < n_entries; ++i) {
 980                                 ir_entity *entity = get_compound_member(type, i);
 981                                 ir_type   *type   = get_entity_type(entity);
 982
 983                                 const ir_initializer_t *sub_initializer
 984                                         = get_initializer_compound_value(initializer, i);
 985
 986                                 unsigned offset = get_entity_offset(entity);
 987                                 unsigned size   = get_initializer_size(sub_initializer, type);
 988
 989                                 if (offset + size > initializer_size) {
 990                                         initializer_size = offset + size;
 991                                 }
 992                         }
 993                         return initializer_size;
 994                 }
 995         }
 996
 997         panic("found invalid initializer");
 998 }
 999
1000 #ifndef NDEBUG
1001 static normal_or_bitfield *glob_vals;
1002 static size_t              max_vals;
1003 #endif
1004
1005 static void emit_bitfield(normal_or_bitfield *vals, size_t offset_bits,
1006                           const ir_initializer_t *initializer, ir_type *type)
1007 {
1008         static const size_t BITS_PER_BYTE = 8;
1009         ir_mode   *mode      = get_type_mode(type);
1010         ir_tarval *tv        = NULL;
1011         int        value_len;
1012         size_t     bit_offset;
1013         size_t     end;
1014         bool       big_endian = be_get_backend_param()->byte_order_big_endian;
1015
1016         switch (get_initializer_kind(initializer)) {
1017         case IR_INITIALIZER_NULL:
1018                 return;
1019         case IR_INITIALIZER_TARVAL:
1020                 tv = get_initializer_tarval_value(initializer);
1021                 break;
1022         case IR_INITIALIZER_CONST: {
1023                 ir_node *node = get_initializer_const_value(initializer);
1024                 if (!is_Const(node)) {
1025                         panic("bitfield initializer not a Const node");
1026                 }
1027                 tv = get_Const_tarval(node);
1028                 break;
1029         }
1030         case IR_INITIALIZER_COMPOUND:
1031                 panic("bitfield initializer is compound");
1032         }
1033         if (tv == NULL) {
1034                 panic("Couldn't get numeric value for bitfield initializer");
1035         }
1036         tv = tarval_convert_to(tv, get_type_mode(type));
1037
1038         value_len  = get_type_size_bytes(get_primitive_base_type(type));
1039         bit_offset = 0;
1040         end        = get_mode_size_bits(mode);
1041         while (bit_offset < end) {
1042                 size_t        src_offset      = bit_offset / BITS_PER_BYTE;
1043                 size_t        src_offset_bits = bit_offset % BITS_PER_BYTE;
1044                 size_t        dst_offset      = (bit_offset+offset_bits) / BITS_PER_BYTE;
1045                 size_t        dst_offset_bits = (bit_offset+offset_bits) % BITS_PER_BYTE;
1046                 size_t        src_bits_len    = end-bit_offset;
1047                 size_t        dst_bits_len    = BITS_PER_BYTE-dst_offset_bits;
1048                 unsigned char curr_bits;
1049                 normal_or_bitfield *val;
1050                 if (src_bits_len > dst_bits_len)
1051                         src_bits_len = dst_bits_len;
1052
1053                 if (big_endian) {
1054                         val = &vals[value_len - dst_offset - 1];
1055                 } else {
1056                         val = &vals[dst_offset];
1057                 }
1058
1059                 assert((val-glob_vals) < (ptrdiff_t) max_vals);
1060                 assert(val->kind == BITFIELD ||
1061                                 (val->kind == NORMAL && val->v.value == NULL));
1062                 val->kind  = BITFIELD;
1063                 curr_bits  = get_tarval_sub_bits(tv, src_offset);
1064                 curr_bits  = curr_bits >> src_offset_bits;
1065                 if (src_offset_bits + src_bits_len > 8) {
1066                         unsigned next_bits = get_tarval_sub_bits(tv, src_offset+1);
1067                         curr_bits |= next_bits << (8 - src_offset_bits);
1068                 }
1069                 curr_bits &= (1 << src_bits_len) - 1;
1070                 val->v.bf_val |= curr_bits << dst_offset_bits;
1071
1072                 bit_offset += dst_bits_len;
1073         }
1074 }
1075
1076 static void emit_ir_initializer(normal_or_bitfield *vals,
1077                                 const ir_initializer_t *initializer,
1078                                 ir_type *type)
1079 {
1080         assert((size_t) (vals - glob_vals) < max_vals);
1081
1082         switch (get_initializer_kind(initializer)) {
1083         case IR_INITIALIZER_NULL:
1084                 return;
1085         case IR_INITIALIZER_TARVAL: {
1086                 size_t i;
1087
1088                 assert(vals->kind != BITFIELD);
1089                 vals->kind     = TARVAL;
1090                 vals->v.tarval = get_initializer_tarval_value(initializer);
1091                 assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval));
1092                 for (i = 1; i < get_type_size_bytes(type); ++i) {
1093                         vals[i].kind    = NORMAL;
1094                         vals[i].v.value = NULL;
1095                 }
1096                 return;
1097         }
1098         case IR_INITIALIZER_CONST: {
1099                 size_t i;
1100
1101                 assert(vals->kind != BITFIELD);
1102                 vals->kind    = NORMAL;
1103                 vals->v.value = get_initializer_const_value(initializer);
1104                 for (i = 1; i < get_type_size_bytes(type); ++i) {
1105                         vals[i].kind    = NORMAL;
1106                         vals[i].v.value = NULL;
1107                 }
1108                 return;
1109         }
1110         case IR_INITIALIZER_COMPOUND: {
1111                 size_t i = 0;
1112                 size_t n = get_initializer_compound_n_entries(initializer);
1113
1114                 if (is_Array_type(type)) {
1115                         ir_type *element_type = get_array_element_type(type);
1116                         size_t   skip         = get_type_size_bytes(element_type);
1117                         size_t   alignment    = get_type_alignment_bytes(element_type);
1118                         size_t   misalign     = skip % alignment;
1119                         if (misalign != 0) {
1120                                 skip += alignment - misalign;
1121                         }
1122
1123                         for (i = 0; i < n; ++i) {
1124                                 ir_initializer_t *sub_initializer
1125                                         = get_initializer_compound_value(initializer, i);
1126
1127                                 emit_ir_initializer(vals, sub_initializer, element_type);
1128
1129                                 vals += skip;
1130                         }
1131                 } else {
1132                         size_t n_members, i;
1133                         assert(is_compound_type(type));
1134                         n_members = get_compound_n_members(type);
1135                         for (i = 0; i < n_members; ++i) {
1136                                 ir_entity        *member    = get_compound_member(type, i);
1137                                 size_t            offset    = get_entity_offset(member);
1138                                 ir_type          *subtype   = get_entity_type(member);
1139                                 ir_mode          *mode      = get_type_mode(subtype);
1140                                 ir_initializer_t *sub_initializer;
1141
1142                                 assert(i < get_initializer_compound_n_entries(initializer));
1143                                 sub_initializer
1144                                         = get_initializer_compound_value(initializer, i);
1145
1146                                 if (mode != NULL) {
1147                                         size_t offset_bits
1148                                                 = get_entity_offset_bits_remainder(member);
1149                                         size_t value_len = get_mode_size_bits(mode);
1150
1151                                         if (offset_bits != 0 ||
1152                                                 (value_len != 8 && value_len != 16 && value_len != 32
1153                                                  && value_len != 64) ||
1154                                                 (is_Primitive_type(subtype) && get_primitive_base_type(subtype) != NULL)) {
1155                                                 emit_bitfield(&vals[offset], offset_bits,
1156                                                               sub_initializer, subtype);
1157                                                 continue;
1158                                         }
1159                                 }
1160
1161                                 emit_ir_initializer(&vals[offset], sub_initializer, subtype);
1162                         }
1163                 }
1164
1165                 return;
1166         }
1167         }
1168         panic("invalid ir_initializer kind found");
1169 }
1170
1171 static void emit_initializer(be_gas_decl_env_t *env, const ir_entity *entity)
1172 {
1173         const ir_initializer_t *initializer = entity->initializer;
1174         ir_type                *type;
1175         normal_or_bitfield     *vals;
1176         size_t                  size;
1177         size_t                  k;
1178
1179         if (initializer_is_string_const(initializer)) {
1180                 emit_string_initializer(initializer);
1181                 return;
1182         }
1183
1184         type = get_entity_type(entity);
1185         size = get_initializer_size(initializer, type);
1186
1187         if (size == 0)
1188                 return;
1189
1190         /*
1191          * In the worst case, every initializer allocates one byte.
1192          * Moreover, initializer might be big, do not allocate on stack.
1193          */
1194         vals = XMALLOCNZ(normal_or_bitfield, size);
1195
1196 #ifndef NDEBUG
1197         glob_vals = vals;
1198         max_vals  = size;
1199 #endif
1200
1201         emit_ir_initializer(vals, initializer, type);
1202
1203         /* now write values sorted */
1204         for (k = 0; k < size; ) {
1205                 int space     = 0;
1206                 int elem_size = 1;
1207                 if (vals[k].kind == NORMAL) {
1208                         if (vals[k].v.value != NULL) {
1209                                 emit_atomic_init(env, vals[k].v.value);
1210                                 elem_size = get_mode_size_bytes(get_irn_mode(vals[k].v.value));
1211                         } else {
1212                                 elem_size = 0;
1213                         }
1214                 } else if (vals[k].kind == TARVAL) {
1215                         ir_tarval *tv   = vals[k].v.tarval;
1216                         size_t     size = get_mode_size_bytes(get_tarval_mode(tv));
1217
1218                         assert(tv != NULL);
1219
1220                         elem_size = size;
1221                         emit_size_type(size);
1222                         emit_arith_tarval(tv, size);
1223                         be_emit_char('\n');
1224                         be_emit_write_line();
1225                 } else {
1226                         assert(vals[k].kind == BITFIELD);
1227                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1228                         be_emit_write_line();
1229                 }
1230
1231                 k += elem_size;
1232                 while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1233                         ++space;
1234                         ++k;
1235                 }
1236
1237                 /* a gap */
1238                 if (space > 0) {
1239                         be_emit_irprintf("\t.space\t%d, 0\n", space);
1240                         be_emit_write_line();
1241                 }
1242         }
1243         xfree(vals);
1244 }
1245
1246 static void emit_compound_graph_init(be_gas_decl_env_t *env,
1247                                      const ir_entity *ent)
1248 {
1249         normal_or_bitfield *vals;
1250         int i, j, n;
1251         unsigned k, last_ofs;
1252
1253         if (entity_is_string_const(ent)) {
1254                 emit_string_cst(ent);
1255                 return;
1256         }
1257
1258         n = get_compound_ent_n_values(ent);
1259
1260         /* Find the initializer size. Sorrily gcc support a nasty feature:
1261            The last field of a compound may be a flexible array. This allows
1262            initializers bigger than the type size. */
1263         last_ofs = get_type_size_bytes(get_entity_type(ent));
1264         for (i = 0; i < n; ++i) {
1265                 unsigned offset         = get_compound_ent_value_offset_bytes(ent, i);
1266                 unsigned bits_remainder = get_compound_ent_value_offset_bit_remainder(ent, i);
1267                 ir_node  *value         = get_compound_ent_value(ent, i);
1268                 unsigned value_len      = get_mode_size_bits(get_irn_mode(value));
1269
1270                 offset += (value_len + bits_remainder + 7) >> 3;
1271
1272                 if (offset > last_ofs) {
1273                         last_ofs = offset;
1274                 }
1275         }
1276
1277         /*
1278          * In the worst case, every initializer allocates one byte.
1279          * Moreover, initializer might be big, do not allocate on stack.
1280          */
1281         vals = XMALLOCNZ(normal_or_bitfield, last_ofs);
1282
1283         /* collect the values and store them at the offsets */
1284         for (i = 0; i < n; ++i) {
1285                 unsigned offset      = get_compound_ent_value_offset_bytes(ent, i);
1286                 int      offset_bits = get_compound_ent_value_offset_bit_remainder(ent, i);
1287                 ir_node  *value      = get_compound_ent_value(ent, i);
1288                 int      value_len   = get_mode_size_bits(get_irn_mode(value));
1289
1290                 assert(offset_bits >= 0);
1291
1292                 if (offset_bits != 0 ||
1293                                 (value_len != 8 && value_len != 16 && value_len != 32 && value_len != 64)) {
1294                         ir_tarval *tv = get_atomic_init_tv(value);
1295                         unsigned char curr_bits, last_bits = 0;
1296                         if (tv == NULL) {
1297                                 panic("Couldn't get numeric value for bitfield initializer '%s'",
1298                                                 get_entity_ld_name(ent));
1299                         }
1300                         /* normalize offset */
1301                         offset += offset_bits >> 3;
1302                         offset_bits &= 7;
1303
1304                         for (j = 0; value_len + offset_bits > 0; ++j) {
1305                                 assert(offset + j < last_ofs);
1306                                 assert(vals[offset + j].kind == BITFIELD || vals[offset + j].v.value == NULL);
1307                                 vals[offset + j].kind = BITFIELD;
1308                                 curr_bits = get_tarval_sub_bits(tv, j);
1309                                 vals[offset + j].v.bf_val |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
1310                                 value_len -= 8;
1311                                 last_bits = curr_bits;
1312                         }
1313                 } else {
1314                         int i;
1315
1316                         assert(offset < last_ofs);
1317                         assert(vals[offset].kind == NORMAL);
1318                         for (i = 1; i < value_len / 8; ++i) {
1319                                 assert(vals[offset + i].v.value == NULL);
1320                         }
1321                         vals[offset].v.value = value;
1322                 }
1323         }
1324
1325         /* now write them sorted */
1326         for (k = 0; k < last_ofs; ) {
1327                 int space = 0, skip = 0;
1328                 if (vals[k].kind == NORMAL) {
1329                         if (vals[k].v.value != NULL) {
1330                                 emit_atomic_init(env, vals[k].v.value);
1331                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
1332                         } else {
1333                                 space = 1;
1334                         }
1335                 } else {
1336                         assert(vals[k].kind == BITFIELD);
1337                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1338                 }
1339
1340                 ++k;
1341                 while (k < last_ofs && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1342                         ++space;
1343                         ++k;
1344                 }
1345                 space -= skip;
1346                 assert(space >= 0);
1347
1348                 /* a gap */
1349                 if (space > 0) {
1350                         be_emit_irprintf("\t.space\t%d, 0\n", space);
1351                         be_emit_write_line();
1352                 }
1353         }
1354         xfree(vals);
1355 }
1356
1357 static void emit_align(unsigned p2alignment)
1358 {
1359         be_emit_irprintf("\t.p2align\t%u\n", log2_floor(p2alignment));
1360         be_emit_write_line();
1361 }
1362
1363 static unsigned get_effective_entity_alignment(const ir_entity *entity)
1364 {
1365         unsigned alignment = get_entity_alignment(entity);
1366         if (alignment == 0) {
1367                 ir_type *type = get_entity_type(entity);
1368                 alignment     = get_type_alignment_bytes(type);
1369         }
1370         return alignment;
1371 }
1372
1373 static void emit_common(const ir_entity *entity)
1374 {
1375         unsigned size      = get_type_size_bytes(get_entity_type(entity));
1376         unsigned alignment = get_effective_entity_alignment(entity);
1377
1378         if (get_entity_linkage(entity) & IR_LINKAGE_WEAK) {
1379                 emit_weak(entity);
1380         }
1381
1382         switch (be_gas_object_file_format) {
1383         case OBJECT_FILE_FORMAT_MACH_O:
1384                 be_emit_cstring("\t.comm ");
1385                 be_gas_emit_entity(entity);
1386                 be_emit_irprintf(",%u,%u\n", size, log2_floor(alignment));
1387                 be_emit_write_line();
1388                 return;
1389         case OBJECT_FILE_FORMAT_ELF:
1390         case OBJECT_FILE_FORMAT_ELF_SPARC:
1391                 be_emit_cstring("\t.comm ");
1392                 be_gas_emit_entity(entity);
1393                 be_emit_irprintf(",%u,%u\n", size, alignment);
1394                 be_emit_write_line();
1395                 return;
1396         case OBJECT_FILE_FORMAT_COFF:
1397                 be_emit_cstring("\t.comm ");
1398                 be_gas_emit_entity(entity);
1399                 be_emit_irprintf(",%u # %u\n", size, alignment);
1400                 be_emit_write_line();
1401                 return;
1402         }
1403         panic("invalid object file format");
1404 }
1405
1406 static void emit_local_common(const ir_entity *entity)
1407 {
1408         unsigned size      = get_type_size_bytes(get_entity_type(entity));
1409         unsigned alignment = get_effective_entity_alignment(entity);
1410
1411         if (get_entity_linkage(entity) & IR_LINKAGE_WEAK) {
1412                 emit_weak(entity);
1413         }
1414
1415         switch (be_gas_object_file_format) {
1416         case OBJECT_FILE_FORMAT_MACH_O:
1417                 be_emit_cstring("\t.lcomm ");
1418                 be_gas_emit_entity(entity);
1419                 be_emit_irprintf(",%u,%u\n", size, log2_floor(alignment));
1420                 be_emit_write_line();
1421                 return;
1422         case OBJECT_FILE_FORMAT_ELF:
1423         case OBJECT_FILE_FORMAT_ELF_SPARC:
1424                 be_emit_cstring("\t.local ");
1425                 be_gas_emit_entity(entity);
1426                 be_emit_cstring("\n");
1427                 be_emit_write_line();
1428                 be_emit_cstring("\t.comm ");
1429                 be_gas_emit_entity(entity);
1430                 be_emit_irprintf(",%u,%u\n", size, alignment);
1431                 be_emit_write_line();
1432                 return;
1433         case OBJECT_FILE_FORMAT_COFF:
1434                 be_emit_cstring("\t.lcomm ");
1435                 be_gas_emit_entity(entity);
1436                 be_emit_irprintf(",%u # %u\n", size, alignment);
1437                 be_emit_write_line();
1438                 return;
1439         }
1440         panic("invalid object file format");
1441 }
1442
1443 static void emit_indirect_symbol(const ir_entity *entity, be_gas_section_t section)
1444 {
1445         /* we can only do PIC code on macho so far */
1446         assert(be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O);
1447
1448         be_gas_emit_entity(entity);
1449         be_emit_cstring(":\n");
1450         be_emit_write_line();
1451         be_emit_cstring("\t.indirect_symbol ");
1452         be_emit_ident(get_entity_ident(entity));
1453         be_emit_char('\n');
1454         be_emit_write_line();
1455         if (section == GAS_SECTION_PIC_TRAMPOLINES) {
1456                 be_emit_cstring("\thlt ; hlt ; hlt ; hlt ; hlt\n");
1457                 be_emit_write_line();
1458         } else {
1459                 assert(section == GAS_SECTION_PIC_SYMBOLS);
1460                 be_emit_cstring("\t.long 0\n");
1461                 be_emit_write_line();
1462         }
1463 }
1464
1465 char const *be_gas_get_private_prefix(void)
1466 {
1467         return be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O ? "L" : ".L";
1468 }
1469
1470 void be_gas_emit_entity(const ir_entity *entity)
1471 {
1472         if (entity->type == firm_code_type) {
1473                 ir_label_t label = get_entity_label(entity);
1474                 be_emit_irprintf("%s_%lu", be_gas_get_private_prefix(), label);
1475                 return;
1476         }
1477
1478         if (get_entity_visibility(entity) == ir_visibility_private) {
1479                 be_emit_string(be_gas_get_private_prefix());
1480         }
1481         be_emit_ident(get_entity_ld_ident(entity));
1482 }
1483
1484 void be_gas_emit_block_name(const ir_node *block)
1485 {
1486         if (has_Block_entity(block)) {
1487                 ir_entity *entity = get_Block_entity(block);
1488                 be_gas_emit_entity(entity);
1489         } else {
1490                 be_emit_irprintf("%s%ld", be_gas_get_private_prefix(), get_irn_node_nr(block));
1491         }
1492 }
1493
1494 /**
1495  * Dump a global entity.
1496  *
1497  * @param env  the gas output environment
1498  * @param ent  the entity to be dumped
1499  */
1500 static void emit_global(be_gas_decl_env_t *env, const ir_entity *entity)
1501 {
1502         ir_type          *type       = get_entity_type(entity);
1503         ident            *ld_ident   = get_entity_ld_ident(entity);
1504         unsigned          alignment  = get_effective_entity_alignment(entity);
1505         be_gas_section_t  section    = determine_section(env, entity);
1506         ir_visibility     visibility = get_entity_visibility(entity);
1507         ir_linkage        linkage    = get_entity_linkage(entity);
1508
1509         /* block labels are already emittet in the code */
1510         if (type == firm_code_type)
1511                 return;
1512
1513         /* we already emitted all methods. Except for the trampolines which
1514          * the assembler/linker generates */
1515         if (is_Method_type(type) && section != GAS_SECTION_PIC_TRAMPOLINES) {
1516                 /* functions with graph are already emitted with
1517                  * be_gas_emit_function_prolog */
1518                 if (get_entity_irg(entity) == NULL) {
1519                         emit_visibility(entity);
1520                 }
1521                 return;
1522         }
1523
1524         be_dbg_variable(entity);
1525
1526         if (section == GAS_SECTION_BSS) {
1527                 ir_visibility visibility = get_entity_visibility(entity);
1528
1529                 switch (visibility) {
1530                 case ir_visibility_local:
1531                 case ir_visibility_private:
1532                         emit_local_common(entity);
1533                         return;
1534                 case ir_visibility_default:
1535                         if (linkage & IR_LINKAGE_MERGE) {
1536                                 emit_common(entity);
1537                                 return;
1538                         }
1539                         break;
1540                 case ir_visibility_external:
1541                         if (linkage & IR_LINKAGE_MERGE)
1542                                 panic("merge link semantic not supported for extern entities");
1543                         break;
1544                 }
1545         }
1546
1547         emit_visibility(entity);
1548         if (visibility == ir_visibility_external) {
1549                 /* nothing to do for externally defined values */
1550                 return;
1551         }
1552
1553         if (!is_po2(alignment))
1554                 panic("alignment not a power of 2");
1555
1556         emit_section(section, entity);
1557
1558         if (section == GAS_SECTION_PIC_TRAMPOLINES
1559                         || section == GAS_SECTION_PIC_SYMBOLS) {
1560                 emit_indirect_symbol(entity, section);
1561                 return;
1562         }
1563
1564         /* alignment */
1565         if (alignment > 1) {
1566                 emit_align(alignment);
1567         }
1568         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_ELF
1569                         && be_gas_emit_types) {
1570                 be_emit_cstring("\t.type\t");
1571                 be_gas_emit_entity(entity);
1572                 be_emit_cstring(", ");
1573                 be_emit_char(be_gas_elf_type_char);
1574                 be_emit_cstring("object\n\t.size\t");\
1575                 be_gas_emit_entity(entity);
1576                 be_emit_irprintf(", %u\n", get_type_size_bytes(type));
1577         }
1578
1579         if (get_id_str(ld_ident)[0] != '\0') {
1580             be_gas_emit_entity(entity);
1581                 be_emit_cstring(":\n");
1582                 be_emit_write_line();
1583         }
1584
1585         if (entity_is_null(entity)) {
1586                 be_emit_irprintf("\t.space %u, 0\n", get_type_size_bytes(type));
1587                 be_emit_write_line();
1588         } else if (entity_has_compound_ent_values(entity)) {
1589                 emit_compound_graph_init(env, entity);
1590         } else {
1591                 assert(entity->initializer != NULL);
1592                 emit_initializer(env, entity);
1593         }
1594 }
1595
1596 /**
1597  * Dumps declarations of global variables and the initialization code.
1598  *
1599  * @param gt                a global like type, either the global or the TLS one
1600  * @param env               an environment
1601  */
1602 static void be_gas_emit_globals(ir_type *gt, be_gas_decl_env_t *env)
1603 {
1604         int i, n = get_compound_n_members(gt);
1605
1606         for (i = 0; i < n; i++) {
1607                 ir_entity *ent = get_compound_member(gt, i);
1608                 emit_global(env, ent);
1609         }
1610 }
1611
1612 /* Generate all entities. */
1613 void be_gas_emit_decls(const be_main_env_t *main_env)
1614 {
1615         be_gas_decl_env_t env;
1616         memset(&env, 0, sizeof(env));
1617
1618         /* dump global type */
1619         env.main_env = main_env;
1620         env.section  = (be_gas_section_t) -1;
1621
1622         be_gas_emit_globals(get_glob_type(), &env);
1623         be_gas_emit_globals(get_tls_type(), &env);
1624         be_gas_emit_globals(get_segment_type(IR_SEGMENT_CONSTRUCTORS), &env);
1625         be_gas_emit_globals(get_segment_type(IR_SEGMENT_DESTRUCTORS), &env);
1626         be_gas_emit_globals(main_env->pic_symbols_type, &env);
1627         be_gas_emit_globals(main_env->pic_trampolines_type, &env);
1628
1629         /**
1630          * ".subsections_via_symbols marks object files which are OK to divide
1631          * their section contents into individual blocks".
1632          * From my understanding this means no label points in the middle of an
1633          * object which we want to address as a whole. Firm code should be fine
1634          * with this.
1635          */
1636         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
1637                 be_emit_cstring("\t.subsections_via_symbols\n");
1638                 be_emit_write_line();
1639         }
1640 }