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