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