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  * Return the pseudo-instruction to be issued for a section switch
  56  * depending on the current flavour.
  57  *
  58  * @param section  the section to switch to
  59  *
  60  * @return  the pseudo-instruction
  61  */
  62 static const char *get_section_name(be_gas_section_t section)
  63 {
  64         static const char *text[OBJECT_FILE_FORMAT_LAST+1][GAS_SECTION_LAST+1] = {
  65                 { /* OBJECT_FILE_FORMAT_ELF */
  66                         ".section\t.text",
  67                         ".section\t.data",
  68                         ".section\t.rodata",
  69                         ".section\t.bss",
  70                         ".section\t.tbss,\"awT\",@nobits",
  71                         ".section\t.ctors,\"aw\",@progbits",
  72                         ".section\t.dtors,\"aw\",@progbits",
  73                         NULL, /* no cstring section */
  74                         NULL,
  75                         NULL
  76                 },
  77                 { /* OBJECT_FILE_FORMAT_COFF */
  78                         ".section\t.text",
  79                         ".section\t.data",
  80                         ".section .rdata,\"dr\"",
  81                         ".section\t.bss",
  82                         ".section\t.tbss,\"awT\",@nobits",
  83                         ".section\t.ctors,\"w\"",
  84                         ".section\t.dtors,\"w\"",
  85                         NULL,
  86                         NULL,
  87                         NULL
  88                 },
  89                 { /* OBJECT_FILE_FORMAT_MACH_O */
  90                         ".text",
  91                         ".data",
  92                         ".const",
  93                         ".data",
  94                         NULL,             /* TLS is not supported on Mach-O */
  95                         ".mod_init_func",
  96                         ".mod_term_func",
  97                         ".cstring",
  98                         ".section\t__IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_instructions,5",
  99                         ".section\t__IMPORT,__pointers,non_lazy_symbol_pointers"
 100                 }
 101         };
 102
 103         assert((int) be_gas_object_file_format >= 0
 104                         && be_gas_object_file_format <= OBJECT_FILE_FORMAT_LAST);
 105         assert((int) section >= 0 && section <= GAS_SECTION_LAST);
 106         return text[be_gas_object_file_format][section];
 107 }
 108
 109 void be_gas_emit_switch_section(be_gas_section_t section)
 110 {
 111         if (current_section == section)
 112                 return;
 113
 114         be_emit_char('\t');
 115         be_emit_string(get_section_name(section));
 116         be_emit_char('\n');
 117         be_emit_write_line();
 118         current_section = section;
 119 }
 120
 121 static void emit_entity_visibility(const ir_entity *entity)
 122 {
 123         ir_visibility visibility = get_entity_visibility(entity);
 124         ir_linkage    linkage    = get_entity_linkage(entity);
 125
 126         if (visibility != ir_visibility_local) {
 127                 be_emit_cstring(".globl ");
 128                 be_emit_ident(get_entity_ld_ident(entity));
 129                 be_emit_char('\n');
 130                 be_emit_write_line();
 131         }
 132         if (linkage & IR_LINKAGE_WEAK) {
 133                 if (! (linkage & IR_LINKAGE_MERGE)) {
 134                         panic("Weak symbols only supported in combination with IR_LINKAGE_MERGE on this architecture");
 135                 }
 136                 be_emit_cstring(".weak ");
 137                 be_emit_ident(get_entity_ld_ident(entity));
 138                 be_emit_char('\n');
 139                 be_emit_write_line();
 140         }
 141 }
 142
 143 void be_gas_emit_function_prolog(ir_entity *entity, unsigned po2alignment)
 144 {
 145         const char *name = get_entity_ld_name(entity);
 146
 147         be_gas_emit_switch_section(GAS_SECTION_TEXT);
 148
 149         /* write the begin line (makes the life easier for scripts parsing the
 150          * assembler) */
 151         be_emit_write_line();
 152         be_emit_cstring("# -- Begin  ");
 153         be_emit_string(name);
 154         be_emit_char('\n');
 155         be_emit_write_line();
 156
 157         if (po2alignment > 0) {
 158                 const char *fill_byte = "";
 159                 unsigned    maximum_skip = (1 << po2alignment) - 1;
 160                 /* gcc fills space between function with 0x90... */
 161                 if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 162                         fill_byte = "0x90";
 163                 }
 164                 be_emit_cstring("\t.p2align ");
 165                 be_emit_irprintf("%u,%s,%u\n", po2alignment, fill_byte, maximum_skip);
 166                 be_emit_write_line();
 167         }
 168         emit_entity_visibility(entity);
 169
 170         switch (be_gas_object_file_format) {
 171         case OBJECT_FILE_FORMAT_ELF:
 172                 be_emit_cstring("\t.type\t");
 173                 be_emit_string(name);
 174                 be_emit_cstring(", ");
 175                 be_emit_char(be_gas_elf_type_char);
 176                 be_emit_cstring("function\n");
 177                 be_emit_write_line();
 178                 break;
 179         case OBJECT_FILE_FORMAT_COFF:
 180                 be_emit_cstring("\t.def\t");
 181                 be_emit_string(name);
 182                 be_emit_cstring(";");
 183                 if (get_entity_visibility(entity) == ir_visibility_local) {
 184                         be_emit_cstring("\t.scl\t3;");
 185                 } else {
 186                         be_emit_cstring("\t.scl\t2;");
 187                 }
 188                 be_emit_cstring("\t.type\t32;\t.endef\n");
 189                 be_emit_write_line();
 190                 break;
 191         case OBJECT_FILE_FORMAT_MACH_O:
 192                 break;
 193         }
 194         be_emit_string(name);
 195         be_emit_cstring(":\n");
 196         be_emit_write_line();
 197 }
 198
 199 void be_gas_emit_function_epilog(ir_entity *entity)
 200 {
 201         const char *name = get_entity_ld_name(entity);
 202
 203         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_ELF) {
 204                 be_emit_cstring("\t.size\t");
 205                 be_emit_string(name);
 206                 be_emit_cstring(", .-");
 207                 be_emit_string(name);
 208                 be_emit_char('\n');
 209                 be_emit_write_line();
 210         }
 211
 212         be_emit_cstring("# -- End  ");
 213         be_emit_string(name);
 214         be_emit_char('\n');
 215         be_emit_write_line();
 216 }
 217
 218 /**
 219  * An environment containing all needed dumper data.
 220  * Currently we create the file completely in memory first, then
 221  * write it to the disk. This is an artifact from the old C-generating backend
 222  * and even there NOT needed. So we might change it in the future.
 223  */
 224 typedef struct _be_gas_decl_env {
 225         be_gas_section_t     section;
 226         const be_main_env_t *main_env;
 227 } be_gas_decl_env_t;
 228
 229 /************************************************************************/
 230
 231 /**
 232  * Output a tarval.
 233  *
 234  * @param tv     the tarval
 235  * @param bytes  the width of the tarvals value in bytes
 236  */
 237 static void dump_arith_tarval(tarval *tv, int bytes)
 238 {
 239         switch (bytes) {
 240         case 1:
 241                 be_emit_irprintf("0x%02x", get_tarval_sub_bits(tv, 0));
 242                 return;
 243
 244         case 2:
 245                 be_emit_irprintf("0x%02x%02x", get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 246                 return;
 247
 248         case 4:
 249                 be_emit_irprintf("0x%02x%02x%02x%02x",
 250                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 251                 return;
 252
 253         case 8:
 254                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x",
 255                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6), get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
 256                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 257                 return;
 258
 259         case 12:
 260                 /* Beware: Mixed endian output!  One little endian number emitted as
 261                  * three longs.  Each long initializer is written in big endian. */
 262                 be_emit_irprintf(
 263                         "\t.long\t0x%02x%02x%02x%02x\n"
 264                         "\t.long\t0x%02x%02x%02x%02x\n"
 265                         "\t.long\t0x%02x%02x%02x%02x",
 266                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
 267                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0),
 268                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
 269                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
 270                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 271                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8)
 272                 );
 273                 return;
 274
 275         case 16:
 276                 /* Beware: Mixed endian output!  One little endian number emitted as
 277                  * three longs.  Each long initializer is written in big endian. */
 278                 be_emit_irprintf(
 279                         "\t.long\t0x%02x%02x%02x%02x\n"
 280                         "\t.long\t0x%02x%02x%02x%02x\n"
 281                         "\t.long\t0x%02x%02x%02x%02x\n"
 282                         "\t.long\t0x%02x%02x%02x%02x",
 283                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
 284                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0),
 285                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
 286                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
 287                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 288                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8),
 289                         get_tarval_sub_bits(tv, 15), get_tarval_sub_bits(tv, 14),
 290                         get_tarval_sub_bits(tv, 13), get_tarval_sub_bits(tv, 12)
 291                 );
 292                 return;
 293         }
 294
 295         panic("Can't dump a tarval with %d bytes", bytes);
 296 }
 297
 298 /**
 299  * Return the label prefix for labeled blocks.
 300  */
 301 const char *be_gas_block_label_prefix(void)
 302 {
 303         return ".LG";
 304 }
 305
 306 /**
 307  * Return the label prefix for labeled instructions.
 308  */
 309 const char *be_gas_insn_label_prefix(void)
 310 {
 311         return ".LE";
 312 }
 313
 314 void be_gas_emit_entity(ir_entity *entity)
 315 {
 316         if (entity->type == firm_code_type) {
 317                 ir_label_t label = get_entity_label(entity);
 318                 be_emit_string(be_gas_block_label_prefix());
 319                 be_emit_irprintf("%lu", label);
 320         } else {
 321                 be_emit_ident(get_entity_ld_ident(entity));
 322         }
 323 }
 324
 325 /**
 326  * Return the tarval of an atomic initializer.
 327  *
 328  * @param init  a node representing the initializer (on the const code irg)
 329  *
 330  * @return the tarval
 331  */
 332 static tarval *get_atomic_init_tv(ir_node *init)
 333 {
 334         for (;;) {
 335                 ir_mode *mode = get_irn_mode(init);
 336
 337                 switch (get_irn_opcode(init)) {
 338
 339                 case iro_Cast:
 340                         init = get_Cast_op(init);
 341                         continue;
 342
 343                 case iro_Conv:
 344                         init = get_Conv_op(init);
 345                         continue;
 346
 347                 case iro_Const:
 348                         return get_Const_tarval(init);
 349
 350                 case iro_SymConst:
 351                         switch (get_SymConst_kind(init)) {
 352                         case symconst_type_size:
 353                                 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(init)), mode);
 354
 355                         case symconst_type_align:
 356                                 return new_tarval_from_long(get_type_alignment_bytes(get_SymConst_type(init)), mode);
 357
 358                         case symconst_ofs_ent:
 359                                 return new_tarval_from_long(get_entity_offset(get_SymConst_entity(init)), mode);
 360
 361                         case symconst_enum_const:
 362                                 return get_enumeration_value(get_SymConst_enum(init));
 363
 364                         default:
 365                                 return NULL;
 366                         }
 367
 368                 default:
 369                         return NULL;
 370                 }
 371         }
 372 }
 373
 374 /**
 375  * Dump an atomic value.
 376  *
 377  * @param env   the gas output environment
 378  * @param init  a node representing the atomic value (on the const code irg)
 379  */
 380 static void do_dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 381 {
 382         ir_mode *mode = get_irn_mode(init);
 383         int bytes     = get_mode_size_bytes(mode);
 384         tarval *tv;
 385         ir_entity *ent;
 386
 387         init = skip_Id(init);
 388
 389         switch (get_irn_opcode(init)) {
 390         case iro_Cast:
 391                 do_dump_atomic_init(env, get_Cast_op(init));
 392                 return;
 393
 394         case iro_Conv:
 395                 do_dump_atomic_init(env, get_Conv_op(init));
 396                 return;
 397
 398         case iro_Const:
 399                 tv = get_Const_tarval(init);
 400
 401                 /* it's a arithmetic value */
 402                 dump_arith_tarval(tv, bytes);
 403                 return;
 404
 405         case iro_SymConst:
 406                 switch (get_SymConst_kind(init)) {
 407                 case symconst_addr_name:
 408                         be_emit_ident(get_SymConst_name(init));
 409                         break;
 410
 411                 case symconst_addr_ent:
 412                         ent = get_SymConst_entity(init);
 413                         be_gas_emit_entity(ent);
 414                         break;
 415
 416                 case symconst_ofs_ent:
 417                         ent = get_SymConst_entity(init);
 418                         be_emit_irprintf("%d", get_entity_offset(ent));
 419                         break;
 420
 421                 case symconst_type_size:
 422                         be_emit_irprintf("%u", get_type_size_bytes(get_SymConst_type(init)));
 423                         break;
 424
 425                 case symconst_type_align:
 426                         be_emit_irprintf("%u", get_type_alignment_bytes(get_SymConst_type(init)));
 427                         break;
 428
 429                 case symconst_enum_const:
 430                         tv = get_enumeration_value(get_SymConst_enum(init));
 431                         dump_arith_tarval(tv, bytes);
 432                         break;
 433
 434                 default:
 435                         assert(!"dump_atomic_init(): don't know how to init from this SymConst");
 436                 }
 437                 return;
 438
 439         case iro_Add:
 440                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 441                         panic("Constant must be int or pointer for '+' to work");
 442                 }
 443                 do_dump_atomic_init(env, get_Add_left(init));
 444                 be_emit_cstring(" + ");
 445                 do_dump_atomic_init(env, get_Add_right(init));
 446                 return;
 447
 448         case iro_Sub:
 449                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 450                         panic("Constant must be int or pointer for '-' to work");
 451                 }
 452                 do_dump_atomic_init(env, get_Sub_left(init));
 453                 be_emit_cstring(" - ");
 454                 do_dump_atomic_init(env, get_Sub_right(init));
 455                 return;
 456
 457         case iro_Mul:
 458                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 459                         panic("Constant must be int or pointer for '*' to work");
 460                 }
 461                 do_dump_atomic_init(env, get_Mul_left(init));
 462                 be_emit_cstring(" * ");
 463                 do_dump_atomic_init(env, get_Mul_right(init));
 464                 return;
 465
 466         case iro_Unknown:
 467                 be_emit_cstring("0");
 468                 return;
 469
 470         default:
 471                 panic("dump_atomic_init(): unsupported IR-node %+F", init);
 472         }
 473 }
 474
 475 /**
 476  * Dumps the type for given size (.byte, .long, ...)
 477  *
 478  * @param size  the size in bytes
 479  */
 480 static void dump_size_type(size_t size) {
 481         switch (size) {
 482         case 1:
 483                 be_emit_cstring("\t.byte\t");
 484                 break;
 485
 486         case 2:
 487                 be_emit_cstring("\t.short\t");
 488                 break;
 489
 490         case 4:
 491                 be_emit_cstring("\t.long\t");
 492                 break;
 493
 494         case 8:
 495                 be_emit_cstring("\t.quad\t");
 496                 break;
 497
 498         case 10:
 499         case 12:
 500         case 16: /* Note: .octa does not work on mac */
 501                 /* handled in arith */
 502                 break;
 503
 504         default:
 505                 panic("Try to dump a type with %u bytes", (unsigned)size);
 506         }
 507 }
 508
 509 /**
 510  * Emit an atomic value.
 511  *
 512  * @param env   the gas output environment
 513  * @param init  a node representing the atomic value (on the const code irg)
 514  */
 515 static void dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 516 {
 517         ir_mode *mode = get_irn_mode(init);
 518         int bytes     = get_mode_size_bytes(mode);
 519
 520         dump_size_type(bytes);
 521         do_dump_atomic_init(env, init);
 522         be_emit_char('\n');
 523         be_emit_write_line();
 524 }
 525
 526 /************************************************************************/
 527 /* Routines to dump global variables                                    */
 528 /************************************************************************/
 529
 530 static int initializer_is_string_const(const ir_initializer_t *initializer)
 531 {
 532         size_t i, len;
 533         int found_printable = 0;
 534
 535         if (initializer->kind != IR_INITIALIZER_COMPOUND)
 536                 return 0;
 537
 538         len = initializer->compound.n_initializers;
 539         if (len < 1)
 540                 return 0;
 541         for (i = 0; i < len; ++i) {
 542                 int               c;
 543                 tarval           *tv;
 544                 ir_mode          *mode;
 545                 ir_initializer_t *sub_initializer
 546                         = initializer->compound.initializers[i];
 547
 548                 if (sub_initializer->kind != IR_INITIALIZER_TARVAL)
 549                         return 0;
 550
 551                 tv   = sub_initializer->tarval.value;
 552                 mode = get_tarval_mode(tv);
 553
 554                 if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8)
 555                         return 0;
 556
 557                 c = get_tarval_long(tv);
 558                 if (isgraph(c) || isspace(c))
 559                         found_printable = 1;
 560                 else if (c != 0)
 561                         return 0;
 562
 563                 if (i == len - 1 && c != '\0')
 564                         return 0;
 565         }
 566
 567         return found_printable;
 568 }
 569
 570 /**
 571  * Determine if an entity is a string constant
 572  * @param ent The entity
 573  * @return 1 if it is a string constant, 0 otherwise
 574  */
 575 static int ent_is_string_const(const ir_entity *ent)
 576 {
 577         ir_type *type, *element_type;
 578         ir_mode *mode;
 579         int i, c, n;
 580
 581         type = get_entity_type(ent);
 582
 583         /* if it's an array */
 584         if (!is_Array_type(type))
 585                 return 0;
 586
 587         element_type = get_array_element_type(type);
 588
 589         /* and the array's element type is primitive */
 590         if (!is_Primitive_type(element_type))
 591                 return 0;
 592
 593         /* and the mode of the element type is an int of
 594          * the same size as the byte mode */
 595         mode = get_type_mode(element_type);
 596         if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8)
 597                 return 0;
 598
 599         if (ent->initializer != NULL) {
 600                 return initializer_is_string_const(ent->initializer);
 601         } else if (entity_has_compound_ent_values(ent)) {
 602                 int found_printable = 0;
 603                 /* if it contains only printable chars and a 0 at the end */
 604                 n = get_compound_ent_n_values(ent);
 605                 for (i = 0; i < n; ++i) {
 606                         ir_node *irn = get_compound_ent_value(ent, i);
 607                         if (! is_Const(irn))
 608                                 return 0;
 609
 610                         c = (int) get_tarval_long(get_Const_tarval(irn));
 611
 612                         if (isgraph(c) || isspace(c))
 613                                 found_printable = 1;
 614                         else if (c != 0)
 615                                 return 0;
 616
 617                         if (i == n - 1 && c != '\0')
 618                                 return 0;
 619                 }
 620                 return found_printable;
 621         }
 622
 623         return 0;
 624 }
 625
 626 /**
 627  * Dump a string constant.
 628  * No checks are made!!
 629  *
 630  * @param ent  The entity to dump.
 631  */
 632 static void dump_string_cst(const ir_entity *ent)
 633 {
 634         int      i, len;
 635         int      output_len;
 636         ir_type *type;
 637         int      type_size;
 638         int      remaining_space;
 639
 640         len        = get_compound_ent_n_values(ent);
 641         output_len = len;
 642         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 643                 be_emit_cstring("\t.ascii \"");
 644         } else {
 645                 be_emit_cstring("\t.string \"");
 646                 output_len -= 1;
 647         }
 648
 649         for (i = 0; i < output_len; ++i) {
 650                 ir_node *irn;
 651                 int c;
 652
 653                 irn = get_compound_ent_value(ent, i);
 654                 c = (int) get_tarval_long(get_Const_tarval(irn));
 655
 656                 switch (c) {
 657                 case '"' : be_emit_cstring("\\\""); break;
 658                 case '\n': be_emit_cstring("\\n"); break;
 659                 case '\r': be_emit_cstring("\\r"); break;
 660                 case '\t': be_emit_cstring("\\t"); break;
 661                 case '\\': be_emit_cstring("\\\\"); break;
 662                 default  :
 663                         if (isprint(c))
 664                                 be_emit_char(c);
 665                         else
 666                                 be_emit_irprintf("\\%o", c);
 667                         break;
 668                 }
 669         }
 670         be_emit_cstring("\"\n");
 671         be_emit_write_line();
 672
 673         type            = get_entity_type(ent);
 674         type_size       = get_type_size_bytes(type);
 675         remaining_space = type_size - len;
 676         assert(remaining_space >= 0);
 677         if (remaining_space > 0) {
 678                 be_emit_irprintf("\t.space\t%d\n", remaining_space);
 679         }
 680 }
 681
 682 static void dump_string_initializer(const ir_initializer_t *initializer)
 683 {
 684         size_t i, len;
 685
 686         len = initializer->compound.n_initializers;
 687         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 688                 be_emit_cstring("\t.ascii \"");
 689         } else {
 690                 be_emit_cstring("\t.string \"");
 691                 len -= 1;
 692         }
 693
 694         for (i = 0; i < len; ++i) {
 695                 const ir_initializer_t *sub_initializer
 696                         = get_initializer_compound_value(initializer, i);
 697
 698                 tarval *tv = get_initializer_tarval_value(sub_initializer);
 699                 int     c  = get_tarval_long(tv);
 700
 701                 switch (c) {
 702                 case '"' : be_emit_cstring("\\\""); break;
 703                 case '\n': be_emit_cstring("\\n"); break;
 704                 case '\r': be_emit_cstring("\\r"); break;
 705                 case '\t': be_emit_cstring("\\t"); break;
 706                 case '\\': be_emit_cstring("\\\\"); break;
 707                 default  :
 708                         if (isprint(c))
 709                                 be_emit_char(c);
 710                         else
 711                                 be_emit_irprintf("\\%o", c);
 712                         break;
 713                 }
 714         }
 715         be_emit_cstring("\"\n");
 716         be_emit_write_line();
 717 }
 718
 719 enum normal_or_bitfield_kind {
 720         NORMAL = 0,
 721         TARVAL,
 722         BITFIELD
 723 };
 724
 725 typedef struct {
 726         enum normal_or_bitfield_kind kind;
 727         union {
 728                 ir_node       *value;
 729                 tarval        *tarval;
 730                 unsigned char  bf_val;
 731         } v;
 732 } normal_or_bitfield;
 733
 734 static int is_type_variable_size(ir_type *type)
 735 {
 736         (void) type;
 737         /* TODO */
 738         return 0;
 739 }
 740
 741 static size_t get_initializer_size(const ir_initializer_t *initializer,
 742                                    ir_type *type)
 743 {
 744         switch (get_initializer_kind(initializer)) {
 745         case IR_INITIALIZER_TARVAL:
 746                 assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type));
 747                 return get_type_size_bytes(type);
 748         case IR_INITIALIZER_CONST:
 749         case IR_INITIALIZER_NULL:
 750                 return get_type_size_bytes(type);
 751         case IR_INITIALIZER_COMPOUND:
 752                 if (!is_type_variable_size(type)) {
 753                         return get_type_size_bytes(type);
 754                 } else {
 755                         unsigned n_entries
 756                                 = get_initializer_compound_n_entries(initializer);
 757                         unsigned i;
 758                         unsigned initializer_size = get_type_size_bytes(type);
 759                         for (i = 0; i < n_entries; ++i) {
 760                                 ir_entity *entity = get_compound_member(type, i);
 761                                 ir_type   *type   = get_entity_type(entity);
 762
 763                                 const ir_initializer_t *sub_initializer
 764                                         = get_initializer_compound_value(initializer, i);
 765
 766                                 unsigned offset = get_entity_offset(entity);
 767                                 unsigned size   = get_initializer_size(sub_initializer, type);
 768
 769                                 if (offset + size > initializer_size) {
 770                                         initializer_size = offset + size;
 771                                 }
 772                         }
 773                         return initializer_size;
 774                 }
 775         }
 776
 777         panic("found invalid initializer");
 778 }
 779
 780 #ifndef NDEBUG
 781 static normal_or_bitfield *glob_vals;
 782 static size_t              max_vals;
 783 #endif
 784
 785 static void dump_bitfield(normal_or_bitfield *vals, size_t offset_bits,
 786                           const ir_initializer_t *initializer, ir_type *type)
 787 {
 788         unsigned char  last_bits = 0;
 789         ir_mode       *mode      = get_type_mode(type);
 790         tarval        *tv        = NULL;
 791         unsigned char  curr_bits;
 792         int            value_len;
 793         int            j;
 794
 795         switch (get_initializer_kind(initializer)) {
 796         case IR_INITIALIZER_NULL:
 797                 return;
 798         case IR_INITIALIZER_TARVAL:
 799                 tv = get_initializer_tarval_value(initializer);
 800                 break;
 801         case IR_INITIALIZER_CONST: {
 802                 ir_node *node = get_initializer_const_value(initializer);
 803                 if (!is_Const(node)) {
 804                         panic("bitfield initializer not a Const node");
 805                 }
 806                 tv = get_Const_tarval(node);
 807                 break;
 808         }
 809         case IR_INITIALIZER_COMPOUND:
 810                 panic("bitfield initializer is compound");
 811         }
 812         if (tv == NULL) {
 813                 panic("Couldn't get numeric value for bitfield initializer");
 814         }
 815         tv = tarval_convert_to(tv, get_type_mode(type));
 816
 817         /* normalize offset */
 818         vals        += offset_bits >> 3;
 819         offset_bits &= 7;
 820         value_len    = get_mode_size_bits(mode);
 821
 822         /* combine bits with existing bits */
 823         for (j = 0; value_len + (int) offset_bits > 0; ++j) {
 824                 assert((size_t) (vals - glob_vals) + j < max_vals);
 825                 assert(vals[j].kind == BITFIELD ||
 826                                 (vals[j].kind == NORMAL && vals[j].v.value == NULL));
 827                 vals[j].kind = BITFIELD;
 828                 curr_bits    = get_tarval_sub_bits(tv, j);
 829                 vals[j].v.bf_val
 830                         |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
 831                 value_len -= 8;
 832                 last_bits = curr_bits;
 833         }
 834 }
 835
 836 static void dump_ir_initializer(normal_or_bitfield *vals,
 837                                 const ir_initializer_t *initializer,
 838                                 ir_type *type)
 839 {
 840         assert((size_t) (vals - glob_vals) < max_vals);
 841
 842         switch (get_initializer_kind(initializer)) {
 843         case IR_INITIALIZER_NULL:
 844                 return;
 845         case IR_INITIALIZER_TARVAL: {
 846                 size_t i;
 847
 848                 assert(vals->kind != BITFIELD);
 849                 vals->kind     = TARVAL;
 850                 vals->v.tarval = get_initializer_tarval_value(initializer);
 851                 assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval));
 852                 for (i = 1; i < get_type_size_bytes(type); ++i) {
 853                         vals[i].kind    = NORMAL;
 854                         vals[i].v.value = NULL;
 855                 }
 856                 return;
 857         }
 858         case IR_INITIALIZER_CONST: {
 859                 size_t i;
 860
 861                 assert(vals->kind != BITFIELD);
 862                 vals->kind    = NORMAL;
 863                 vals->v.value = get_initializer_const_value(initializer);
 864                 for (i = 1; i < get_type_size_bytes(type); ++i) {
 865                         vals[i].kind    = NORMAL;
 866                         vals[i].v.value = NULL;
 867                 }
 868                 return;
 869         }
 870         case IR_INITIALIZER_COMPOUND: {
 871                 size_t i = 0;
 872                 size_t n = get_initializer_compound_n_entries(initializer);
 873
 874                 if (is_Array_type(type)) {
 875                         ir_type *element_type = get_array_element_type(type);
 876                         size_t   skip         = get_type_size_bytes(element_type);
 877                         size_t   alignment    = get_type_alignment_bytes(element_type);
 878                         size_t   misalign     = skip % alignment;
 879                         if (misalign != 0) {
 880                                 skip += alignment - misalign;
 881                         }
 882
 883                         for (i = 0; i < n; ++i) {
 884                                 ir_initializer_t *sub_initializer
 885                                         = get_initializer_compound_value(initializer, i);
 886
 887                                 dump_ir_initializer(vals, sub_initializer, element_type);
 888
 889                                 vals += skip;
 890                         }
 891                 } else {
 892                         size_t n_members, i;
 893                         assert(is_compound_type(type));
 894                         n_members = get_compound_n_members(type);
 895                         for (i = 0; i < n_members; ++i) {
 896                                 ir_entity        *member    = get_compound_member(type, i);
 897                                 size_t            offset    = get_entity_offset(member);
 898                                 ir_type          *subtype   = get_entity_type(member);
 899                                 ir_mode          *mode      = get_type_mode(subtype);
 900                                 ir_initializer_t *sub_initializer;
 901
 902                                 assert(i < get_initializer_compound_n_entries(initializer));
 903                                 sub_initializer
 904                                         = get_initializer_compound_value(initializer, i);
 905
 906                                 if (mode != NULL) {
 907                                         size_t offset_bits
 908                                                 = get_entity_offset_bits_remainder(member);
 909                                         size_t value_len   = get_mode_size_bits(mode);
 910
 911                                         if (offset_bits != 0 ||
 912                                                 (value_len != 8 && value_len != 16 && value_len != 32
 913                                                  && value_len != 64)) {
 914                                                 dump_bitfield(&vals[offset], offset_bits,
 915                                                               sub_initializer, subtype);
 916                                                 continue;
 917                                         }
 918                                 }
 919
 920                                 dump_ir_initializer(&vals[offset], sub_initializer, subtype);
 921                         }
 922                 }
 923
 924                 return;
 925         }
 926         }
 927         panic("invalid ir_initializer kind found");
 928 }
 929
 930 static void dump_initializer(be_gas_decl_env_t *env, const ir_entity *entity)
 931 {
 932         const ir_initializer_t *initializer = entity->initializer;
 933         ir_type                *type;
 934         normal_or_bitfield     *vals;
 935         size_t                  size;
 936         size_t                  k;
 937
 938         if (initializer_is_string_const(initializer)) {
 939                 dump_string_initializer(initializer);
 940                 return;
 941         }
 942
 943         type = get_entity_type(entity);
 944         size = get_initializer_size(initializer, type);
 945
 946         if (size == 0)
 947                 return;
 948
 949         /*
 950          * In the worst case, every initializer allocates one byte.
 951          * Moreover, initializer might be big, do not allocate on stack.
 952          */
 953         vals = XMALLOCNZ(normal_or_bitfield, size);
 954
 955 #ifndef NDEBUG
 956         glob_vals = vals;
 957         max_vals  = size;
 958 #endif
 959
 960         dump_ir_initializer(vals, initializer, type);
 961
 962         /* now write values sorted */
 963         for (k = 0; k < size; ) {
 964                 int space     = 0;
 965                 int elem_size = 1;
 966                 if (vals[k].kind == NORMAL) {
 967                         if (vals[k].v.value != NULL) {
 968                                 dump_atomic_init(env, vals[k].v.value);
 969                                 elem_size = get_mode_size_bytes(get_irn_mode(vals[k].v.value));
 970                         } else {
 971                                 elem_size = 0;
 972                         }
 973                 } else if (vals[k].kind == TARVAL) {
 974                         tarval *tv   = vals[k].v.tarval;
 975                         size_t  size = get_mode_size_bytes(get_tarval_mode(tv));
 976
 977                         assert(tv != NULL);
 978
 979                         elem_size = size;
 980                         dump_size_type(size);
 981                         dump_arith_tarval(tv, size);
 982                         be_emit_char('\n');
 983                         be_emit_write_line();
 984                 } else {
 985                         assert(vals[k].kind == BITFIELD);
 986                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
 987                         be_emit_write_line();
 988                 }
 989
 990                 k += elem_size;
 991                 while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
 992                         ++space;
 993                         ++k;
 994                 }
 995
 996                 /* a gap */
 997                 if (space > 0) {
 998                         be_emit_irprintf("\t.space\t%d\n", space);
 999                         be_emit_write_line();
1000                 }
1001         }
1002         xfree(vals);
1003 }
1004
1005 static void dump_compound_graph_init(be_gas_decl_env_t *env,
1006                                      const ir_entity *ent)
1007 {
1008         normal_or_bitfield *vals;
1009         int i, j, n;
1010         unsigned k, last_ofs;
1011
1012         if (ent_is_string_const(ent)) {
1013                 dump_string_cst(ent);
1014                 return;
1015         }
1016
1017         n = get_compound_ent_n_values(ent);
1018
1019         /* Find the initializer size. Sorrily gcc support a nasty feature:
1020            The last field of a compound may be a flexible array. This allows
1021            initializers bigger than the type size. */
1022         last_ofs = get_type_size_bytes(get_entity_type(ent));
1023         for (i = 0; i < n; ++i) {
1024                 unsigned offset         = get_compound_ent_value_offset_bytes(ent, i);
1025                 unsigned bits_remainder = get_compound_ent_value_offset_bit_remainder(ent, i);
1026                 ir_node  *value         = get_compound_ent_value(ent, i);
1027                 unsigned value_len      = get_mode_size_bits(get_irn_mode(value));
1028
1029                 offset += (value_len + bits_remainder + 7) >> 3;
1030
1031                 if (offset > last_ofs) {
1032                         last_ofs = offset;
1033                 }
1034         }
1035
1036         /*
1037          * In the worst case, every initializer allocates one byte.
1038          * Moreover, initializer might be big, do not allocate on stack.
1039          */
1040         vals = XMALLOCNZ(normal_or_bitfield, last_ofs);
1041
1042         /* collect the values and store them at the offsets */
1043         for (i = 0; i < n; ++i) {
1044                 unsigned offset      = get_compound_ent_value_offset_bytes(ent, i);
1045                 int      offset_bits = get_compound_ent_value_offset_bit_remainder(ent, i);
1046                 ir_node  *value      = get_compound_ent_value(ent, i);
1047                 int      value_len   = get_mode_size_bits(get_irn_mode(value));
1048
1049                 assert(offset_bits >= 0);
1050
1051                 if (offset_bits != 0 ||
1052                                 (value_len != 8 && value_len != 16 && value_len != 32 && value_len != 64)) {
1053                         tarval *tv = get_atomic_init_tv(value);
1054                         unsigned char curr_bits, last_bits = 0;
1055                         if (tv == NULL) {
1056                                 panic("Couldn't get numeric value for bitfield initializer '%s'",
1057                                                 get_entity_ld_name(ent));
1058                         }
1059                         /* normalize offset */
1060                         offset += offset_bits >> 3;
1061                         offset_bits &= 7;
1062
1063                         for (j = 0; value_len + offset_bits > 0; ++j) {
1064                                 assert(offset + j < last_ofs);
1065                                 assert(vals[offset + j].kind == BITFIELD || vals[offset + j].v.value == NULL);
1066                                 vals[offset + j].kind = BITFIELD;
1067                                 curr_bits = get_tarval_sub_bits(tv, j);
1068                                 vals[offset + j].v.bf_val |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
1069                                 value_len -= 8;
1070                                 last_bits = curr_bits;
1071                         }
1072                 } else {
1073                         int i;
1074
1075                         assert(offset < last_ofs);
1076                         assert(vals[offset].kind == NORMAL);
1077                         for (i = 1; i < value_len / 8; ++i) {
1078                                 assert(vals[offset + i].v.value == NULL);
1079                         }
1080                         vals[offset].v.value = value;
1081                 }
1082         }
1083
1084         /* now write them sorted */
1085         for (k = 0; k < last_ofs; ) {
1086                 int space = 0, skip = 0;
1087                 if (vals[k].kind == NORMAL) {
1088                         if (vals[k].v.value != NULL) {
1089                                 dump_atomic_init(env, vals[k].v.value);
1090                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
1091                         } else {
1092                                 space = 1;
1093                         }
1094                 } else {
1095                         assert(vals[k].kind == BITFIELD);
1096                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1097                 }
1098
1099                 ++k;
1100                 while (k < last_ofs && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1101                         ++space;
1102                         ++k;
1103                 }
1104                 space -= skip;
1105                 assert(space >= 0);
1106
1107                 /* a gap */
1108                 if (space > 0) {
1109                         be_emit_irprintf("\t.space\t%d\n", space);
1110                         be_emit_write_line();
1111                 }
1112         }
1113         xfree(vals);
1114 }
1115
1116 static void emit_align(unsigned p2alignment)
1117 {
1118         be_emit_irprintf("\t.p2align\t%u\n", log2_floor(p2alignment));
1119         be_emit_write_line();
1120 }
1121
1122 static unsigned get_effective_entity_alignment(const ir_entity *entity)
1123 {
1124         unsigned alignment = get_entity_alignment(entity);
1125         if (alignment == 0) {
1126                 ir_type *type = get_entity_type(entity);
1127                 alignment     = get_type_alignment_bytes(type);
1128         }
1129         return alignment;
1130 }
1131
1132 static be_gas_section_t determine_section(be_gas_decl_env_t *env,
1133                                           const ir_entity *entity)
1134 {
1135         ir_type *owner = get_entity_owner(entity);
1136
1137         if (owner == get_segment_type(IR_SEGMENT_GLOBAL)) {
1138                 ir_linkage linkage = get_entity_linkage(entity);
1139                 if (linkage & IR_LINKAGE_CONSTANT) {
1140                         /* mach-o is the only one with a cstring section */
1141                         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O
1142                                         && ent_is_string_const(entity))
1143                                 return GAS_SECTION_CSTRING;
1144
1145                         return GAS_SECTION_RODATA;
1146                 }
1147                 if (!entity_has_definition(entity))
1148                         return GAS_SECTION_BSS;
1149
1150                 return GAS_SECTION_DATA;
1151
1152         } else if (owner == env->main_env->pic_symbols_type) {
1153                 return GAS_SECTION_PIC_SYMBOLS;
1154         } else if (owner == env->main_env->pic_trampolines_type) {
1155                 return GAS_SECTION_PIC_TRAMPOLINES;
1156         } else if (owner == get_segment_type(IR_SEGMENT_CONSTRUCTORS)) {
1157                 return GAS_SECTION_CONSTRUCTORS;
1158         } else if (owner == get_segment_type(IR_SEGMENT_DESTRUCTORS)) {
1159                 return GAS_SECTION_DESTRUCTORS;
1160         } else if (owner == get_segment_type(IR_SEGMENT_THREAD_LOCAL)) {
1161                 return GAS_SECTION_TLS;
1162         }
1163
1164         panic("Couldn't determine section for %+F?!?", entity);
1165 }
1166
1167 static void emit_common(const ir_entity *ent)
1168 {
1169         const char *name      = get_entity_ld_name(ent);
1170         unsigned    size      = get_type_size_bytes(get_entity_type(ent));
1171         unsigned    alignment = get_effective_entity_alignment(ent);
1172
1173         switch (be_gas_object_file_format) {
1174         case OBJECT_FILE_FORMAT_MACH_O:
1175                 be_emit_irprintf("\t.comm %s,%u,%u\n", name, size,
1176                                  log2_floor(alignment));
1177                 be_emit_write_line();
1178                 return;
1179         case OBJECT_FILE_FORMAT_ELF:
1180                 be_emit_irprintf("\t.comm %s,%u,%u\n", name, size, alignment);
1181                 be_emit_write_line();
1182                 return;
1183         case OBJECT_FILE_FORMAT_COFF:
1184                 be_emit_irprintf("\t.comm %s,%u # %u\n", name, size, alignment);
1185                 be_emit_write_line();
1186                 return;
1187         }
1188         panic("invalid object file format");
1189 }
1190
1191 static void dump_indirect_symbol(const ir_entity *entity, be_gas_section_t section)
1192 {
1193         /* we can only do PIC code on macho so far */
1194         assert(be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O);
1195
1196         be_emit_ident(get_entity_ld_ident(entity));
1197         be_emit_cstring(":\n");
1198         be_emit_write_line();
1199         be_emit_cstring("\t.indirect_symbol ");
1200         be_emit_ident(get_entity_ident(entity));
1201         be_emit_char('\n');
1202         be_emit_write_line();
1203         if (section == GAS_SECTION_PIC_TRAMPOLINES) {
1204                 be_emit_cstring("\thlt ; hlt ; hlt ; hlt ; hlt\n");
1205                 be_emit_write_line();
1206         } else {
1207                 assert(section == GAS_SECTION_PIC_SYMBOLS);
1208                 be_emit_cstring("\t.long 0\n");
1209                 be_emit_write_line();
1210         }
1211 }
1212
1213 /**
1214  * Dump a global entity.
1215  *
1216  * @param env  the gas output environment
1217  * @param ent  the entity to be dumped
1218  */
1219 static void dump_global(be_gas_decl_env_t *env, const ir_entity *ent)
1220 {
1221         ir_type          *type           = get_entity_type(ent);
1222         ident            *ld_ident       = get_entity_ld_ident(ent);
1223         unsigned          alignment      = get_effective_entity_alignment(ent);
1224         be_gas_section_t  section        = determine_section(env, ent);
1225
1226         /* we already emitted all methods. Except for the trampolines which
1227          * the assembler/linker generates */
1228         if (is_Method_type(type) && section != GAS_SECTION_PIC_TRAMPOLINES) {
1229                 return;
1230         }
1231         /* block labels are already emittet in the code */
1232         if (type == firm_code_type)
1233                 return;
1234
1235         be_dbg_variable(ent);
1236
1237         /* nothing to do for externally defined values */
1238         if (get_entity_visibility(ent) == ir_visibility_external)
1239                 return;
1240
1241         if (!is_po2(alignment))
1242                 panic("alignment not a power of 2");
1243
1244         if (section == GAS_SECTION_BSS &&
1245                         (get_entity_linkage(ent) & IR_LINKAGE_MERGE)) {
1246                 if (get_entity_visibility(ent) != ir_visibility_default) {
1247                         panic("merge link semantic not supported for local/extern entities");
1248                 }
1249                 emit_common(ent);
1250                 return;
1251         }
1252
1253         be_gas_emit_switch_section(section);
1254
1255         if (section == GAS_SECTION_PIC_TRAMPOLINES
1256                         || section == GAS_SECTION_PIC_SYMBOLS) {
1257                 dump_indirect_symbol(ent, section);
1258                 return;
1259         }
1260
1261         /* alignment */
1262         if (alignment > 1) {
1263                 emit_align(alignment);
1264         }
1265         emit_entity_visibility(ent);
1266         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_ELF
1267                         && be_gas_emit_types) {
1268                 be_emit_cstring("\t.type\t");
1269                 be_emit_ident(ld_ident);
1270                 be_emit_cstring(", ");
1271                 be_emit_char(be_gas_elf_type_char);
1272                 be_emit_cstring("object\n\t.size\t");
1273                 be_emit_ident(ld_ident);
1274                 be_emit_irprintf(", %u\n", get_type_size_bytes(type));
1275         }
1276         be_emit_ident(ld_ident);
1277         be_emit_cstring(":\n");
1278         be_emit_write_line();
1279
1280         if (ent->initializer != NULL) {
1281                 dump_initializer(env, ent);
1282         } else if(entity_has_compound_ent_values(ent)) {
1283                 dump_compound_graph_init(env, ent);
1284         } else {
1285                 /* uninitialized */
1286                 be_emit_irprintf("\t.space %u\n", get_type_size_bytes(type));
1287                 be_emit_write_line();
1288         }
1289 }
1290
1291 /**
1292  * Dumps declarations of global variables and the initialization code.
1293  *
1294  * @param gt                a global like type, either the global or the TLS one
1295  * @param env               an environment
1296  */
1297 static void be_gas_dump_globals(ir_type *gt, be_gas_decl_env_t *env)
1298 {
1299         int i, n = get_compound_n_members(gt);
1300
1301         for (i = 0; i < n; i++) {
1302                 ir_entity *ent = get_compound_member(gt, i);
1303                 dump_global(env, ent);
1304         }
1305 }
1306
1307 /************************************************************************/
1308
1309 /* Generate all entities. */
1310 void be_gas_emit_decls(const be_main_env_t *main_env)
1311 {
1312         be_gas_decl_env_t env;
1313         memset(&env, 0, sizeof(env));
1314
1315         /* dump global type */
1316         env.main_env = main_env;
1317         env.section  = (be_gas_section_t) -1;
1318
1319         be_gas_dump_globals(get_glob_type(), &env);
1320         be_gas_dump_globals(get_tls_type(), &env);
1321         be_gas_dump_globals(get_segment_type(IR_SEGMENT_CONSTRUCTORS), &env);
1322         be_gas_dump_globals(get_segment_type(IR_SEGMENT_DESTRUCTORS), &env);
1323         be_gas_dump_globals(main_env->pic_symbols_type, &env);
1324         be_gas_dump_globals(main_env->pic_trampolines_type, &env);
1325
1326         /**
1327          * ".subsections_via_symbols marks object files which are OK to divide
1328          * their section contents into individual blocks".
1329          * From my understanding this means no label points in the middle of an
1330          * object which we want to address as a whole. Firm code should be fine
1331          * with this.
1332          */
1333         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
1334                 be_emit_cstring("\t.subsections_via_symbols\n");
1335                 be_emit_write_line();
1336         }
1337 }