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