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

   1 /*
   2  * Copyright (C) 1995-2011 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 bool initializer_is_string_const(const ir_initializer_t *initializer)
 266 {
 267         size_t i, len;
 268         bool found_printable = false;
 269
 270         if (initializer->kind != IR_INITIALIZER_COMPOUND)
 271                 return false;
 272
 273         len = initializer->compound.n_initializers;
 274         if (len < 1)
 275                 return false;
 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 false;
 286
 287                 mode = get_tarval_mode(tv);
 288                 if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8)
 289                         return false;
 290
 291                 c = get_tarval_long(tv);
 292                 if (isgraph(c) || isspace(c))
 293                         found_printable = true;
 294                 else if (c != 0)
 295                         return false;
 296
 297                 if (i == len - 1 && c != '\0')
 298                         return false;
 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                         && get_entity_ld_name(entity)[0] != '\0') {
 494                 be_emit_cstring("\t.no_dead_strip ");
 495                 be_gas_emit_entity(entity);
 496                 be_emit_char('\n');
 497                 be_emit_write_line();
 498         }
 499 }
 500
 501 void be_gas_emit_function_prolog(const ir_entity *entity, unsigned po2alignment)
 502 {
 503         be_gas_section_t section = determine_section(NULL, entity);
 504         emit_section(section, entity);
 505
 506         /* write the begin line (makes the life easier for scripts parsing the
 507          * assembler) */
 508         be_emit_write_line();
 509         be_emit_cstring("# -- Begin  ");
 510         be_gas_emit_entity(entity);
 511         be_emit_char('\n');
 512         be_emit_write_line();
 513
 514         if (po2alignment > 0) {
 515                 const char *fill_byte = "";
 516                 unsigned    maximum_skip = (1 << po2alignment) - 1;
 517                 /* gcc fills space between function with 0x90... */
 518                 if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 519                         fill_byte = "0x90";
 520                 }
 521                 be_emit_cstring("\t.p2align ");
 522                 be_emit_irprintf("%u,%s,%u\n", po2alignment, fill_byte, maximum_skip);
 523                 be_emit_write_line();
 524         }
 525         emit_visibility(entity);
 526
 527         switch (be_gas_object_file_format) {
 528         case OBJECT_FILE_FORMAT_ELF:
 529         case OBJECT_FILE_FORMAT_ELF_SPARC:
 530                 be_emit_cstring("\t.type\t");
 531                 be_gas_emit_entity(entity);
 532                 be_emit_cstring(", ");
 533                 be_emit_char(be_gas_elf_type_char);
 534                 be_emit_cstring("function\n");
 535                 be_emit_write_line();
 536                 break;
 537         case OBJECT_FILE_FORMAT_COFF:
 538                 be_emit_cstring("\t.def\t");
 539                 be_gas_emit_entity(entity);
 540                 be_emit_cstring(";");
 541                 if (get_entity_visibility(entity) == ir_visibility_local) {
 542                         be_emit_cstring("\t.scl\t3;");
 543                 } else {
 544                         be_emit_cstring("\t.scl\t2;");
 545                 }
 546                 be_emit_cstring("\t.type\t32;\t.endef\n");
 547                 be_emit_write_line();
 548                 break;
 549         case OBJECT_FILE_FORMAT_MACH_O:
 550                 break;
 551         }
 552         be_gas_emit_entity(entity);
 553         be_emit_cstring(":\n");
 554         be_emit_write_line();
 555 }
 556
 557 void be_gas_emit_function_epilog(const ir_entity *entity)
 558 {
 559         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_ELF) {
 560                 be_emit_cstring("\t.size\t");
 561                 be_gas_emit_entity(entity);
 562                 be_emit_cstring(", .-");
 563                 be_gas_emit_entity(entity);
 564                 be_emit_char('\n');
 565                 be_emit_write_line();
 566         }
 567
 568         be_emit_cstring("# -- End  ");
 569         be_gas_emit_entity(entity);
 570         be_emit_char('\n');
 571         be_emit_write_line();
 572 }
 573
 574 /**
 575  * Output a tarval.
 576  *
 577  * @param tv     the tarval
 578  * @param bytes  the width of the tarvals value in bytes
 579  */
 580 static void emit_arith_tarval(ir_tarval *tv, int bytes)
 581 {
 582         switch (bytes) {
 583         case 1:
 584                 be_emit_irprintf("0x%02x", get_tarval_sub_bits(tv, 0));
 585                 return;
 586
 587         case 2:
 588                 be_emit_irprintf("0x%02x%02x", get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 589                 return;
 590
 591         case 4:
 592                 be_emit_irprintf("0x%02x%02x%02x%02x",
 593                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 594                 return;
 595
 596         case 8:
 597                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x",
 598                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6), get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
 599                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 600                 return;
 601
 602         case 12:
 603                 /* Beware: Mixed endian output!  One little endian number emitted as
 604                  * three longs.  Each long initializer is written in big endian. */
 605                 be_emit_irprintf(
 606                         "\t.long\t0x%02x%02x%02x%02x\n"
 607                         "\t.long\t0x%02x%02x%02x%02x\n"
 608                         "\t.long\t0x%02x%02x%02x%02x",
 609                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
 610                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0),
 611                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
 612                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
 613                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 614                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8)
 615                 );
 616                 return;
 617
 618         case 16:
 619                 /* Beware: Mixed endian output!  One little endian number emitted as
 620                  * three longs.  Each long initializer is written in big endian. */
 621                 be_emit_irprintf(
 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\n"
 625                         "\t.long\t0x%02x%02x%02x%02x",
 626                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
 627                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0),
 628                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
 629                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
 630                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 631                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8),
 632                         get_tarval_sub_bits(tv, 15), get_tarval_sub_bits(tv, 14),
 633                         get_tarval_sub_bits(tv, 13), get_tarval_sub_bits(tv, 12)
 634                 );
 635                 return;
 636         }
 637
 638         panic("Can't dump a tarval with %d bytes", bytes);
 639 }
 640
 641 /**
 642  * Return the label prefix for labeled instructions.
 643  */
 644 const char *be_gas_insn_label_prefix(void)
 645 {
 646         return ".LE";
 647 }
 648
 649 /**
 650  * Return the tarval of an atomic initializer.
 651  *
 652  * @param init  a node representing the initializer (on the const code irg)
 653  *
 654  * @return the tarval
 655  */
 656 static ir_tarval *get_atomic_init_tv(ir_node *init)
 657 {
 658         for (;;) {
 659                 ir_mode *mode = get_irn_mode(init);
 660
 661                 switch (get_irn_opcode(init)) {
 662
 663                 case iro_Cast:
 664                         init = get_Cast_op(init);
 665                         continue;
 666
 667                 case iro_Conv:
 668                         init = get_Conv_op(init);
 669                         continue;
 670
 671                 case iro_Const:
 672                         return get_Const_tarval(init);
 673
 674                 case iro_SymConst:
 675                         switch (get_SymConst_kind(init)) {
 676                         case symconst_type_size:
 677                                 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(init)), mode);
 678
 679                         case symconst_type_align:
 680                                 return new_tarval_from_long(get_type_alignment_bytes(get_SymConst_type(init)), mode);
 681
 682                         case symconst_ofs_ent:
 683                                 return new_tarval_from_long(get_entity_offset(get_SymConst_entity(init)), mode);
 684
 685                         case symconst_enum_const:
 686                                 return get_enumeration_value(get_SymConst_enum(init));
 687
 688                         default:
 689                                 return NULL;
 690                         }
 691
 692                 default:
 693                         return NULL;
 694                 }
 695         }
 696 }
 697
 698 /**
 699  * Dump an atomic value.
 700  *
 701  * @param env   the gas output environment
 702  * @param init  a node representing the atomic value (on the const code irg)
 703  */
 704 static void do_emit_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 705 {
 706         ir_mode *mode = get_irn_mode(init);
 707         int bytes     = get_mode_size_bytes(mode);
 708         ir_tarval *tv;
 709         ir_entity *ent;
 710
 711         init = skip_Id(init);
 712
 713         switch (get_irn_opcode(init)) {
 714         case iro_Cast:
 715                 do_emit_atomic_init(env, get_Cast_op(init));
 716                 return;
 717
 718         case iro_Conv:
 719                 do_emit_atomic_init(env, get_Conv_op(init));
 720                 return;
 721
 722         case iro_Const:
 723                 tv = get_Const_tarval(init);
 724
 725                 /* it's an arithmetic value */
 726                 emit_arith_tarval(tv, bytes);
 727                 return;
 728
 729         case iro_SymConst:
 730                 switch (get_SymConst_kind(init)) {
 731                 case symconst_addr_ent:
 732                         ent = get_SymConst_entity(init);
 733                         be_gas_emit_entity(ent);
 734                         break;
 735
 736                 case symconst_ofs_ent:
 737                         ent = get_SymConst_entity(init);
 738                         be_emit_irprintf("%d", get_entity_offset(ent));
 739                         break;
 740
 741                 case symconst_type_size:
 742                         be_emit_irprintf("%u", get_type_size_bytes(get_SymConst_type(init)));
 743                         break;
 744
 745                 case symconst_type_align:
 746                         be_emit_irprintf("%u", get_type_alignment_bytes(get_SymConst_type(init)));
 747                         break;
 748
 749                 case symconst_enum_const:
 750                         tv = get_enumeration_value(get_SymConst_enum(init));
 751                         emit_arith_tarval(tv, bytes);
 752                         break;
 753
 754                 default:
 755                         assert(!"emit_atomic_init(): don't know how to init from this SymConst");
 756                 }
 757                 return;
 758
 759         case iro_Add:
 760                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 761                         panic("Constant must be int or pointer for '+' to work");
 762                 }
 763                 do_emit_atomic_init(env, get_Add_left(init));
 764                 be_emit_cstring(" + ");
 765                 do_emit_atomic_init(env, get_Add_right(init));
 766                 return;
 767
 768         case iro_Sub:
 769                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 770                         panic("Constant must be int or pointer for '-' to work");
 771                 }
 772                 do_emit_atomic_init(env, get_Sub_left(init));
 773                 be_emit_cstring(" - ");
 774                 do_emit_atomic_init(env, get_Sub_right(init));
 775                 return;
 776
 777         case iro_Mul:
 778                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 779                         panic("Constant must be int or pointer for '*' to work");
 780                 }
 781                 do_emit_atomic_init(env, get_Mul_left(init));
 782                 be_emit_cstring(" * ");
 783                 do_emit_atomic_init(env, get_Mul_right(init));
 784                 return;
 785
 786         case iro_Unknown:
 787                 be_emit_cstring("0");
 788                 return;
 789
 790         default:
 791                 panic("emit_atomic_init(): unsupported IR-node %+F", init);
 792         }
 793 }
 794
 795 /**
 796  * Dumps the type for given size (.byte, .long, ...)
 797  *
 798  * @param size  the size in bytes
 799  */
 800 static void emit_size_type(size_t size)
 801 {
 802         switch (size) {
 803         case 1:
 804                 be_emit_cstring("\t.byte\t");
 805                 break;
 806
 807         case 2:
 808                 be_emit_cstring("\t.short\t");
 809                 break;
 810
 811         case 4:
 812                 be_emit_cstring("\t.long\t");
 813                 break;
 814
 815         case 8:
 816                 be_emit_cstring("\t.quad\t");
 817                 break;
 818
 819         case 10:
 820         case 12:
 821         case 16: /* Note: .octa does not work on mac */
 822                 /* handled in arith */
 823                 break;
 824
 825         default:
 826                 panic("Try to dump a type with %u bytes", (unsigned)size);
 827         }
 828 }
 829
 830 /**
 831  * Emit an atomic value.
 832  *
 833  * @param env   the gas output environment
 834  * @param init  a node representing the atomic value (on the const code irg)
 835  */
 836 static void emit_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 837 {
 838         ir_mode *mode = get_irn_mode(init);
 839         int bytes     = get_mode_size_bytes(mode);
 840
 841         emit_size_type(bytes);
 842         do_emit_atomic_init(env, init);
 843         be_emit_char('\n');
 844         be_emit_write_line();
 845 }
 846
 847 /**
 848  * Dump a string constant.
 849  * No checks are made!!
 850  *
 851  * @param ent  The entity to dump.
 852  */
 853 static void emit_string_cst(const ir_entity *ent)
 854 {
 855         int      i, len;
 856         int      output_len;
 857         ir_type *type;
 858         int      type_size;
 859         int      remaining_space;
 860
 861         len        = get_compound_ent_n_values(ent);
 862         output_len = len;
 863         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 864                 be_emit_cstring("\t.ascii \"");
 865         } else {
 866                 be_emit_cstring("\t.string \"");
 867                 output_len -= 1;
 868         }
 869
 870         for (i = 0; i < output_len; ++i) {
 871                 ir_node *irn;
 872                 int c;
 873
 874                 irn = get_compound_ent_value(ent, i);
 875                 c = (int) get_tarval_long(get_Const_tarval(irn));
 876
 877                 switch (c) {
 878                 case '"' : be_emit_cstring("\\\""); break;
 879                 case '\n': be_emit_cstring("\\n"); break;
 880                 case '\r': be_emit_cstring("\\r"); break;
 881                 case '\t': be_emit_cstring("\\t"); break;
 882                 case '\\': be_emit_cstring("\\\\"); break;
 883                 default  :
 884                         if (isprint(c))
 885                                 be_emit_char(c);
 886                         else
 887                                 be_emit_irprintf("\\%o", c);
 888                         break;
 889                 }
 890         }
 891         be_emit_cstring("\"\n");
 892         be_emit_write_line();
 893
 894         type            = get_entity_type(ent);
 895         type_size       = get_type_size_bytes(type);
 896         remaining_space = type_size - len;
 897         assert(remaining_space >= 0);
 898         if (remaining_space > 0) {
 899                 be_emit_irprintf("\t.space\t%d, 0\n", remaining_space);
 900         }
 901 }
 902
 903 static size_t emit_string_initializer(const ir_initializer_t *initializer)
 904 {
 905         size_t i, len;
 906
 907         len = initializer->compound.n_initializers;
 908         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 909                 be_emit_cstring("\t.ascii \"");
 910         } else {
 911                 be_emit_cstring("\t.string \"");
 912                 len -= 1;
 913         }
 914
 915         for (i = 0; i < len; ++i) {
 916                 const ir_initializer_t *sub_initializer
 917                         = get_initializer_compound_value(initializer, i);
 918
 919                 ir_tarval *tv = get_initializer_tarval(sub_initializer);
 920                 int        c  = get_tarval_long(tv);
 921
 922                 switch (c) {
 923                 case '"' : be_emit_cstring("\\\""); break;
 924                 case '\n': be_emit_cstring("\\n"); break;
 925                 case '\r': be_emit_cstring("\\r"); break;
 926                 case '\t': be_emit_cstring("\\t"); break;
 927                 case '\\': be_emit_cstring("\\\\"); break;
 928                 default  :
 929                         if (isprint(c))
 930                                 be_emit_char(c);
 931                         else
 932                                 be_emit_irprintf("\\%o", c);
 933                         break;
 934                 }
 935         }
 936         be_emit_cstring("\"\n");
 937         be_emit_write_line();
 938
 939         return initializer->compound.n_initializers;
 940 }
 941
 942 typedef enum normal_or_bitfield_kind {
 943         NORMAL = 0,
 944         TARVAL,
 945         STRING,
 946         BITFIELD
 947 } normal_or_bitfield_kind;
 948
 949 typedef struct {
 950         normal_or_bitfield_kind kind;
 951         union {
 952                 ir_node                *value;
 953                 ir_tarval              *tarval;
 954                 unsigned char           bf_val;
 955                 const ir_initializer_t *string;
 956         } v;
 957 } normal_or_bitfield;
 958
 959 static int is_type_variable_size(ir_type *type)
 960 {
 961         (void) type;
 962         /* TODO */
 963         return 0;
 964 }
 965
 966 static size_t get_initializer_size(const ir_initializer_t *initializer,
 967                                    ir_type *type)
 968 {
 969         switch (get_initializer_kind(initializer)) {
 970         case IR_INITIALIZER_TARVAL:
 971                 assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type));
 972                 return get_type_size_bytes(type);
 973         case IR_INITIALIZER_CONST:
 974         case IR_INITIALIZER_NULL:
 975                 return get_type_size_bytes(type);
 976         case IR_INITIALIZER_COMPOUND:
 977                 if (!is_type_variable_size(type)) {
 978                         return get_type_size_bytes(type);
 979                 } else {
 980                         size_t n_entries
 981                                 = get_initializer_compound_n_entries(initializer);
 982                         size_t i;
 983                         unsigned initializer_size = get_type_size_bytes(type);
 984                         for (i = 0; i < n_entries; ++i) {
 985                                 ir_entity *entity = get_compound_member(type, i);
 986                                 ir_type   *type   = get_entity_type(entity);
 987
 988                                 const ir_initializer_t *sub_initializer
 989                                         = get_initializer_compound_value(initializer, i);
 990
 991                                 unsigned offset = get_entity_offset(entity);
 992                                 unsigned size   = get_initializer_size(sub_initializer, type);
 993
 994                                 if (offset + size > initializer_size) {
 995                                         initializer_size = offset + size;
 996                                 }
 997                         }
 998                         return initializer_size;
 999                 }
1000         }
1001
1002         panic("found invalid initializer");
1003 }
1004
1005 #ifndef NDEBUG
1006 static normal_or_bitfield *glob_vals;
1007 static size_t              max_vals;
1008 #endif
1009
1010 static void emit_bitfield(normal_or_bitfield *vals, size_t offset_bits,
1011                           const ir_initializer_t *initializer, ir_type *type)
1012 {
1013         static const size_t BITS_PER_BYTE = 8;
1014         ir_mode   *mode      = get_type_mode(type);
1015         ir_tarval *tv        = NULL;
1016         int        value_len;
1017         size_t     bit_offset;
1018         size_t     end;
1019         bool       big_endian = be_get_backend_param()->byte_order_big_endian;
1020
1021         switch (get_initializer_kind(initializer)) {
1022         case IR_INITIALIZER_NULL:
1023                 return;
1024         case IR_INITIALIZER_TARVAL:
1025                 tv = get_initializer_tarval_value(initializer);
1026                 break;
1027         case IR_INITIALIZER_CONST: {
1028                 ir_node *node = get_initializer_const_value(initializer);
1029                 if (!is_Const(node)) {
1030                         panic("bitfield initializer not a Const node");
1031                 }
1032                 tv = get_Const_tarval(node);
1033                 break;
1034         }
1035         case IR_INITIALIZER_COMPOUND:
1036                 panic("bitfield initializer is compound");
1037         }
1038         if (tv == NULL) {
1039                 panic("Couldn't get numeric value for bitfield initializer");
1040         }
1041         tv = tarval_convert_to(tv, get_type_mode(type));
1042
1043         value_len  = get_type_size_bytes(get_primitive_base_type(type));
1044         bit_offset = 0;
1045         end        = get_mode_size_bits(mode);
1046         while (bit_offset < end) {
1047                 size_t        src_offset      = bit_offset / BITS_PER_BYTE;
1048                 size_t        src_offset_bits = bit_offset % BITS_PER_BYTE;
1049                 size_t        dst_offset      = (bit_offset+offset_bits) / BITS_PER_BYTE;
1050                 size_t        dst_offset_bits = (bit_offset+offset_bits) % BITS_PER_BYTE;
1051                 size_t        src_bits_len    = end-bit_offset;
1052                 size_t        dst_bits_len    = BITS_PER_BYTE-dst_offset_bits;
1053                 unsigned char curr_bits;
1054                 normal_or_bitfield *val;
1055                 if (src_bits_len > dst_bits_len)
1056                         src_bits_len = dst_bits_len;
1057
1058                 if (big_endian) {
1059                         val = &vals[value_len - dst_offset - 1];
1060                 } else {
1061                         val = &vals[dst_offset];
1062                 }
1063
1064                 assert((val-glob_vals) < (ptrdiff_t) max_vals);
1065                 assert(val->kind == BITFIELD ||
1066                                 (val->kind == NORMAL && val->v.value == NULL));
1067                 val->kind  = BITFIELD;
1068                 curr_bits  = get_tarval_sub_bits(tv, src_offset);
1069                 curr_bits  = curr_bits >> src_offset_bits;
1070                 if (src_offset_bits + src_bits_len > 8) {
1071                         unsigned next_bits = get_tarval_sub_bits(tv, src_offset+1);
1072                         curr_bits |= next_bits << (8 - src_offset_bits);
1073                 }
1074                 curr_bits &= (1 << src_bits_len) - 1;
1075                 val->v.bf_val |= curr_bits << dst_offset_bits;
1076
1077                 bit_offset += dst_bits_len;
1078         }
1079 }
1080
1081 static void emit_ir_initializer(normal_or_bitfield *vals,
1082                                 const ir_initializer_t *initializer,
1083                                 ir_type *type)
1084 {
1085         assert((size_t) (vals - glob_vals) < max_vals);
1086
1087         if (initializer_is_string_const(initializer)) {
1088                 assert(vals->kind != BITFIELD);
1089                 vals->kind     = STRING;
1090                 vals->v.string = initializer;
1091                 return;
1092         }
1093
1094         switch (get_initializer_kind(initializer)) {
1095         case IR_INITIALIZER_NULL:
1096                 return;
1097         case IR_INITIALIZER_TARVAL: {
1098                 size_t i;
1099
1100                 assert(vals->kind != BITFIELD);
1101                 vals->kind     = TARVAL;
1102                 vals->v.tarval = get_initializer_tarval_value(initializer);
1103                 assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval));
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_CONST: {
1111                 size_t i;
1112
1113                 assert(vals->kind != BITFIELD);
1114                 vals->kind    = NORMAL;
1115                 vals->v.value = get_initializer_const_value(initializer);
1116                 for (i = 1; i < get_type_size_bytes(type); ++i) {
1117                         vals[i].kind    = NORMAL;
1118                         vals[i].v.value = NULL;
1119                 }
1120                 return;
1121         }
1122         case IR_INITIALIZER_COMPOUND: {
1123                 size_t i = 0;
1124                 size_t n = get_initializer_compound_n_entries(initializer);
1125
1126                 if (is_Array_type(type)) {
1127                         ir_type *element_type = get_array_element_type(type);
1128                         size_t   skip         = get_type_size_bytes(element_type);
1129                         size_t   alignment    = get_type_alignment_bytes(element_type);
1130                         size_t   misalign     = skip % alignment;
1131                         if (misalign != 0) {
1132                                 skip += alignment - misalign;
1133                         }
1134
1135                         for (i = 0; i < n; ++i) {
1136                                 ir_initializer_t *sub_initializer
1137                                         = get_initializer_compound_value(initializer, i);
1138
1139                                 emit_ir_initializer(vals, sub_initializer, element_type);
1140
1141                                 vals += skip;
1142                         }
1143                 } else {
1144                         size_t n_members, i;
1145                         assert(is_compound_type(type));
1146                         n_members = get_compound_n_members(type);
1147                         for (i = 0; i < n_members; ++i) {
1148                                 ir_entity        *member    = get_compound_member(type, i);
1149                                 size_t            offset    = get_entity_offset(member);
1150                                 ir_type          *subtype   = get_entity_type(member);
1151                                 ir_mode          *mode      = get_type_mode(subtype);
1152                                 ir_initializer_t *sub_initializer;
1153
1154                                 assert(i < get_initializer_compound_n_entries(initializer));
1155                                 sub_initializer
1156                                         = get_initializer_compound_value(initializer, i);
1157
1158                                 if (mode != NULL) {
1159                                         size_t offset_bits
1160                                                 = get_entity_offset_bits_remainder(member);
1161                                         size_t value_len = get_mode_size_bits(mode);
1162
1163                                         if (offset_bits != 0 ||
1164                                                 (value_len != 8 && value_len != 16 && value_len != 32
1165                                                  && value_len != 64) ||
1166                                                 (is_Primitive_type(subtype) && get_primitive_base_type(subtype) != NULL)) {
1167                                                 emit_bitfield(&vals[offset], offset_bits,
1168                                                               sub_initializer, subtype);
1169                                                 continue;
1170                                         }
1171                                 }
1172
1173                                 emit_ir_initializer(&vals[offset], sub_initializer, subtype);
1174                         }
1175                 }
1176
1177                 return;
1178         }
1179         }
1180         panic("invalid ir_initializer kind found");
1181 }
1182
1183 static void emit_initializer(be_gas_decl_env_t *env, const ir_entity *entity)
1184 {
1185         const ir_initializer_t *initializer = entity->initializer;
1186         ir_type                *type;
1187         normal_or_bitfield     *vals;
1188         size_t                  size;
1189         size_t                  k;
1190
1191         if (initializer_is_string_const(initializer)) {
1192                 emit_string_initializer(initializer);
1193                 return;
1194         }
1195
1196         type = get_entity_type(entity);
1197         size = get_initializer_size(initializer, type);
1198
1199         if (size == 0)
1200                 return;
1201
1202         /*
1203          * In the worst case, every initializer allocates one byte.
1204          * Moreover, initializer might be big, do not allocate on stack.
1205          */
1206         vals = XMALLOCNZ(normal_or_bitfield, size);
1207
1208 #ifndef NDEBUG
1209         glob_vals = vals;
1210         max_vals  = size;
1211 #endif
1212
1213         emit_ir_initializer(vals, initializer, type);
1214
1215         /* now write values sorted */
1216         for (k = 0; k < size; ) {
1217                 int                     space     = 0;
1218                 int                     elem_size = 1;
1219                 normal_or_bitfield_kind kind      = vals[k].kind;
1220                 switch (kind) {
1221                 case NORMAL:
1222                         if (vals[k].v.value != NULL) {
1223                                 emit_atomic_init(env, vals[k].v.value);
1224                                 elem_size = get_mode_size_bytes(get_irn_mode(vals[k].v.value));
1225                         } else {
1226                                 elem_size = 0;
1227                         }
1228                         break;
1229                 case TARVAL: {
1230                         ir_tarval *tv   = vals[k].v.tarval;
1231                         size_t     size = get_mode_size_bytes(get_tarval_mode(tv));
1232
1233                         assert(tv != NULL);
1234
1235                         elem_size = size;
1236                         emit_size_type(size);
1237                         emit_arith_tarval(tv, size);
1238                         be_emit_char('\n');
1239                         be_emit_write_line();
1240                         break;
1241                 }
1242                 case STRING:
1243                         elem_size = emit_string_initializer(vals[k].v.string);
1244                         break;
1245                 case BITFIELD:
1246                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1247                         be_emit_write_line();
1248                         break;
1249                 }
1250
1251                 k += elem_size;
1252                 while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1253                         ++space;
1254                         ++k;
1255                 }
1256
1257                 /* a gap */
1258                 if (space > 0) {
1259                         be_emit_irprintf("\t.space\t%d, 0\n", space);
1260                         be_emit_write_line();
1261                 }
1262         }
1263         xfree(vals);
1264 }
1265
1266 static void emit_compound_graph_init(be_gas_decl_env_t *env,
1267                                      const ir_entity *ent)
1268 {
1269         normal_or_bitfield *vals;
1270         int i, j, n;
1271         unsigned k, last_ofs;
1272
1273         if (entity_is_string_const(ent)) {
1274                 emit_string_cst(ent);
1275                 return;
1276         }
1277
1278         n = get_compound_ent_n_values(ent);
1279
1280         /* Find the initializer size. Sorrily gcc support a nasty feature:
1281            The last field of a compound may be a flexible array. This allows
1282            initializers bigger than the type size. */
1283         last_ofs = get_type_size_bytes(get_entity_type(ent));
1284         for (i = 0; i < n; ++i) {
1285                 unsigned offset         = get_compound_ent_value_offset_bytes(ent, i);
1286                 unsigned bits_remainder = get_compound_ent_value_offset_bit_remainder(ent, i);
1287                 ir_node  *value         = get_compound_ent_value(ent, i);
1288                 unsigned value_len      = get_mode_size_bits(get_irn_mode(value));
1289
1290                 offset += (value_len + bits_remainder + 7) >> 3;
1291
1292                 if (offset > last_ofs) {
1293                         last_ofs = offset;
1294                 }
1295         }
1296
1297         /*
1298          * In the worst case, every initializer allocates one byte.
1299          * Moreover, initializer might be big, do not allocate on stack.
1300          */
1301         vals = XMALLOCNZ(normal_or_bitfield, last_ofs);
1302
1303         /* collect the values and store them at the offsets */
1304         for (i = 0; i < n; ++i) {
1305                 unsigned offset      = get_compound_ent_value_offset_bytes(ent, i);
1306                 int      offset_bits = get_compound_ent_value_offset_bit_remainder(ent, i);
1307                 ir_node  *value      = get_compound_ent_value(ent, i);
1308                 int      value_len   = get_mode_size_bits(get_irn_mode(value));
1309
1310                 assert(offset_bits >= 0);
1311
1312                 if (offset_bits != 0 ||
1313                                 (value_len != 8 && value_len != 16 && value_len != 32 && value_len != 64)) {
1314                         ir_tarval *tv = get_atomic_init_tv(value);
1315                         unsigned char curr_bits, last_bits = 0;
1316                         if (tv == NULL) {
1317                                 panic("Couldn't get numeric value for bitfield initializer '%s'",
1318                                                 get_entity_ld_name(ent));
1319                         }
1320                         /* normalize offset */
1321                         offset += offset_bits >> 3;
1322                         offset_bits &= 7;
1323
1324                         for (j = 0; value_len + offset_bits > 0; ++j) {
1325                                 assert(offset + j < last_ofs);
1326                                 assert(vals[offset + j].kind == BITFIELD || vals[offset + j].v.value == NULL);
1327                                 vals[offset + j].kind = BITFIELD;
1328                                 curr_bits = get_tarval_sub_bits(tv, j);
1329                                 vals[offset + j].v.bf_val |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
1330                                 value_len -= 8;
1331                                 last_bits = curr_bits;
1332                         }
1333                 } else {
1334                         int i;
1335
1336                         assert(offset < last_ofs);
1337                         assert(vals[offset].kind == NORMAL);
1338                         for (i = 1; i < value_len / 8; ++i) {
1339                                 assert(vals[offset + i].v.value == NULL);
1340                         }
1341                         vals[offset].v.value = value;
1342                 }
1343         }
1344
1345         /* now write them sorted */
1346         for (k = 0; k < last_ofs; ) {
1347                 int space = 0, skip = 0;
1348                 if (vals[k].kind == NORMAL) {
1349                         if (vals[k].v.value != NULL) {
1350                                 emit_atomic_init(env, vals[k].v.value);
1351                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
1352                         } else {
1353                                 space = 1;
1354                         }
1355                 } else {
1356                         assert(vals[k].kind == BITFIELD);
1357                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1358                 }
1359
1360                 ++k;
1361                 while (k < last_ofs && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1362                         ++space;
1363                         ++k;
1364                 }
1365                 space -= skip;
1366                 assert(space >= 0);
1367
1368                 /* a gap */
1369                 if (space > 0) {
1370                         be_emit_irprintf("\t.space\t%d, 0\n", space);
1371                         be_emit_write_line();
1372                 }
1373         }
1374         xfree(vals);
1375 }
1376
1377 static void emit_align(unsigned p2alignment)
1378 {
1379         be_emit_irprintf("\t.p2align\t%u\n", log2_floor(p2alignment));
1380         be_emit_write_line();
1381 }
1382
1383 static unsigned get_effective_entity_alignment(const ir_entity *entity)
1384 {
1385         unsigned alignment = get_entity_alignment(entity);
1386         if (alignment == 0) {
1387                 ir_type *type = get_entity_type(entity);
1388                 alignment     = get_type_alignment_bytes(type);
1389         }
1390         return alignment;
1391 }
1392
1393 static void emit_common(const ir_entity *entity)
1394 {
1395         unsigned size      = get_type_size_bytes(get_entity_type(entity));
1396         unsigned alignment = get_effective_entity_alignment(entity);
1397
1398         if (get_entity_linkage(entity) & IR_LINKAGE_WEAK) {
1399                 emit_weak(entity);
1400         }
1401
1402         switch (be_gas_object_file_format) {
1403         case OBJECT_FILE_FORMAT_MACH_O:
1404                 be_emit_cstring("\t.comm ");
1405                 be_gas_emit_entity(entity);
1406                 be_emit_irprintf(",%u,%u\n", size, log2_floor(alignment));
1407                 be_emit_write_line();
1408                 return;
1409         case OBJECT_FILE_FORMAT_ELF:
1410         case OBJECT_FILE_FORMAT_ELF_SPARC:
1411                 be_emit_cstring("\t.comm ");
1412                 be_gas_emit_entity(entity);
1413                 be_emit_irprintf(",%u,%u\n", size, alignment);
1414                 be_emit_write_line();
1415                 return;
1416         case OBJECT_FILE_FORMAT_COFF:
1417                 be_emit_cstring("\t.comm ");
1418                 be_gas_emit_entity(entity);
1419                 be_emit_irprintf(",%u # %u\n", size, alignment);
1420                 be_emit_write_line();
1421                 return;
1422         }
1423         panic("invalid object file format");
1424 }
1425
1426 static void emit_local_common(const ir_entity *entity)
1427 {
1428         unsigned size      = get_type_size_bytes(get_entity_type(entity));
1429         unsigned alignment = get_effective_entity_alignment(entity);
1430
1431         if (get_entity_linkage(entity) & IR_LINKAGE_WEAK) {
1432                 emit_weak(entity);
1433         }
1434
1435         switch (be_gas_object_file_format) {
1436         case OBJECT_FILE_FORMAT_MACH_O:
1437                 be_emit_cstring("\t.lcomm ");
1438                 be_gas_emit_entity(entity);
1439                 be_emit_irprintf(",%u,%u\n", size, log2_floor(alignment));
1440                 be_emit_write_line();
1441                 return;
1442         case OBJECT_FILE_FORMAT_ELF:
1443         case OBJECT_FILE_FORMAT_ELF_SPARC:
1444                 be_emit_cstring("\t.local ");
1445                 be_gas_emit_entity(entity);
1446                 be_emit_cstring("\n");
1447                 be_emit_write_line();
1448                 be_emit_cstring("\t.comm ");
1449                 be_gas_emit_entity(entity);
1450                 be_emit_irprintf(",%u,%u\n", size, alignment);
1451                 be_emit_write_line();
1452                 return;
1453         case OBJECT_FILE_FORMAT_COFF:
1454                 be_emit_cstring("\t.lcomm ");
1455                 be_gas_emit_entity(entity);
1456                 be_emit_irprintf(",%u # %u\n", size, alignment);
1457                 be_emit_write_line();
1458                 return;
1459         }
1460         panic("invalid object file format");
1461 }
1462
1463 static void emit_indirect_symbol(const ir_entity *entity, be_gas_section_t section)
1464 {
1465         /* we can only do PIC code on macho so far */
1466         assert(be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O);
1467
1468         be_gas_emit_entity(entity);
1469         be_emit_cstring(":\n");
1470         be_emit_write_line();
1471         be_emit_cstring("\t.indirect_symbol ");
1472         be_emit_ident(get_entity_ident(entity));
1473         be_emit_char('\n');
1474         be_emit_write_line();
1475         if (section == GAS_SECTION_PIC_TRAMPOLINES) {
1476                 be_emit_cstring("\thlt ; hlt ; hlt ; hlt ; hlt\n");
1477                 be_emit_write_line();
1478         } else {
1479                 assert(section == GAS_SECTION_PIC_SYMBOLS);
1480                 be_emit_cstring("\t.long 0\n");
1481                 be_emit_write_line();
1482         }
1483 }
1484
1485 char const *be_gas_get_private_prefix(void)
1486 {
1487         return be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O ? "L" : ".L";
1488 }
1489
1490 void be_gas_emit_entity(const ir_entity *entity)
1491 {
1492         if (entity->type == firm_code_type) {
1493                 ir_label_t label = get_entity_label(entity);
1494                 be_emit_irprintf("%s_%lu", be_gas_get_private_prefix(), label);
1495                 return;
1496         }
1497
1498         if (get_entity_visibility(entity) == ir_visibility_private) {
1499                 be_emit_string(be_gas_get_private_prefix());
1500         }
1501         be_emit_ident(get_entity_ld_ident(entity));
1502 }
1503
1504 void be_gas_emit_block_name(const ir_node *block)
1505 {
1506         if (has_Block_entity(block)) {
1507                 ir_entity *entity = get_Block_entity(block);
1508                 be_gas_emit_entity(entity);
1509         } else {
1510                 be_emit_irprintf("%s%ld", be_gas_get_private_prefix(), get_irn_node_nr(block));
1511         }
1512 }
1513
1514 /**
1515  * Dump a global entity.
1516  *
1517  * @param env  the gas output environment
1518  * @param ent  the entity to be dumped
1519  */
1520 static void emit_global(be_gas_decl_env_t *env, const ir_entity *entity)
1521 {
1522         ir_type          *type       = get_entity_type(entity);
1523         ident            *ld_ident   = get_entity_ld_ident(entity);
1524         unsigned          alignment  = get_effective_entity_alignment(entity);
1525         be_gas_section_t  section    = determine_section(env, entity);
1526         ir_visibility     visibility = get_entity_visibility(entity);
1527         ir_linkage        linkage    = get_entity_linkage(entity);
1528
1529         /* block labels are already emittet in the code */
1530         if (type == firm_code_type)
1531                 return;
1532
1533         /* we already emitted all methods. Except for the trampolines which
1534          * the assembler/linker generates */
1535         if (is_Method_type(type) && section != GAS_SECTION_PIC_TRAMPOLINES) {
1536                 /* functions with graph are already emitted with
1537                  * be_gas_emit_function_prolog */
1538                 if (get_entity_irg(entity) == NULL) {
1539                         emit_visibility(entity);
1540                 }
1541                 return;
1542         }
1543
1544         be_dbg_variable(entity);
1545
1546         if (section == GAS_SECTION_BSS) {
1547                 switch (visibility) {
1548                 case ir_visibility_local:
1549                 case ir_visibility_private:
1550                         emit_local_common(entity);
1551                         return;
1552                 case ir_visibility_default:
1553                         if (linkage & IR_LINKAGE_MERGE) {
1554                                 emit_common(entity);
1555                                 return;
1556                         }
1557                         break;
1558                 case ir_visibility_external:
1559                         if (linkage & IR_LINKAGE_MERGE)
1560                                 panic("merge link semantic not supported for extern entities");
1561                         break;
1562                 }
1563         }
1564
1565         emit_visibility(entity);
1566         if (visibility == ir_visibility_external) {
1567                 /* nothing to do for externally defined values */
1568                 return;
1569         }
1570
1571         if (!is_po2(alignment))
1572                 panic("alignment not a power of 2");
1573
1574         emit_section(section, entity);
1575
1576         if (section == GAS_SECTION_PIC_TRAMPOLINES
1577                         || section == GAS_SECTION_PIC_SYMBOLS) {
1578                 emit_indirect_symbol(entity, section);
1579                 return;
1580         }
1581
1582         /* alignment */
1583         if (alignment > 1) {
1584                 emit_align(alignment);
1585         }
1586         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_ELF
1587                         && be_gas_emit_types
1588                         && visibility != ir_visibility_private) {
1589                 be_emit_cstring("\t.type\t");
1590                 be_gas_emit_entity(entity);
1591                 be_emit_cstring(", ");
1592                 be_emit_char(be_gas_elf_type_char);
1593                 be_emit_cstring("object\n\t.size\t");\
1594                 be_gas_emit_entity(entity);
1595                 be_emit_irprintf(", %u\n", get_type_size_bytes(type));
1596         }
1597
1598         if (get_id_str(ld_ident)[0] != '\0') {
1599             be_gas_emit_entity(entity);
1600                 be_emit_cstring(":\n");
1601                 be_emit_write_line();
1602         }
1603
1604         if (entity_is_null(entity)) {
1605                 unsigned size = get_type_size_bytes(type);
1606                 if (size > 0) {
1607                         be_emit_irprintf("\t.space %u, 0\n", get_type_size_bytes(type));
1608                         be_emit_write_line();
1609                 }
1610         } else if (entity_has_compound_ent_values(entity)) {
1611                 emit_compound_graph_init(env, entity);
1612         } else {
1613                 assert(entity->initializer != NULL);
1614                 emit_initializer(env, entity);
1615         }
1616 }
1617
1618 /**
1619  * Dumps declarations of global variables and the initialization code.
1620  *
1621  * @param gt                a global like type, either the global or the TLS one
1622  * @param env               an environment
1623  */
1624 static void be_gas_emit_globals(ir_type *gt, be_gas_decl_env_t *env)
1625 {
1626         size_t i, n = get_compound_n_members(gt);
1627
1628         for (i = 0; i < n; i++) {
1629                 ir_entity *ent = get_compound_member(gt, i);
1630                 emit_global(env, ent);
1631         }
1632 }
1633
1634 /* Generate all entities. */
1635 void be_gas_emit_decls(const be_main_env_t *main_env)
1636 {
1637         be_gas_decl_env_t env;
1638         memset(&env, 0, sizeof(env));
1639
1640         /* dump global type */
1641         env.main_env = main_env;
1642         env.section  = (be_gas_section_t) -1;
1643
1644         be_gas_emit_globals(get_glob_type(), &env);
1645         be_gas_emit_globals(get_tls_type(), &env);
1646         be_gas_emit_globals(get_segment_type(IR_SEGMENT_CONSTRUCTORS), &env);
1647         be_gas_emit_globals(get_segment_type(IR_SEGMENT_DESTRUCTORS), &env);
1648         be_gas_emit_globals(main_env->pic_symbols_type, &env);
1649         be_gas_emit_globals(main_env->pic_trampolines_type, &env);
1650
1651         /**
1652          * ".subsections_via_symbols marks object files which are OK to divide
1653          * their section contents into individual blocks".
1654          * From my understanding this means no label points in the middle of an
1655          * object which we want to address as a whole. Firm code should be fine
1656          * with this.
1657          */
1658         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
1659                 be_emit_cstring("\t.subsections_via_symbols\n");
1660                 be_emit_write_line();
1661         }
1662 }