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                         NULL,             /* are there destructors on mach-o? */
  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                 be_emit_irprintf(
 277                         "\t.long\t0x%02x%02x%02x%02x0x%02x%02x%02x%02x0x%02x%02x%02x%02x0x%02x%02x%02x%02x",
 278                         get_tarval_sub_bits(tv, 15), get_tarval_sub_bits(tv, 16),
 279                         get_tarval_sub_bits(tv, 13), get_tarval_sub_bits(tv, 12),
 280                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 281                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8),
 282                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
 283                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
 284                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
 285                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0)
 286                 );
 287                 return;
 288         }
 289
 290         panic("Can't dump a tarval with %d bytes", bytes);
 291 }
 292
 293 /**
 294  * Return the label prefix for labeled blocks.
 295  */
 296 const char *be_gas_block_label_prefix(void)
 297 {
 298         return ".LG";
 299 }
 300
 301 /**
 302  * Return the label prefix for labeled instructions.
 303  */
 304 const char *be_gas_insn_label_prefix(void)
 305 {
 306         return ".LE";
 307 }
 308
 309 void be_gas_emit_entity(ir_entity *entity)
 310 {
 311         if (entity->type == firm_code_type) {
 312                 ir_label_t label = get_entity_label(entity);
 313                 be_emit_string(be_gas_block_label_prefix());
 314                 be_emit_irprintf("%lu", label);
 315         } else {
 316                 be_emit_ident(get_entity_ld_ident(entity));
 317         }
 318 }
 319
 320 /**
 321  * Return the tarval of an atomic initializer.
 322  *
 323  * @param init  a node representing the initializer (on the const code irg)
 324  *
 325  * @return the tarval
 326  */
 327 static tarval *get_atomic_init_tv(ir_node *init)
 328 {
 329         for (;;) {
 330                 ir_mode *mode = get_irn_mode(init);
 331
 332                 switch (get_irn_opcode(init)) {
 333
 334                 case iro_Cast:
 335                         init = get_Cast_op(init);
 336                         continue;
 337
 338                 case iro_Conv:
 339                         init = get_Conv_op(init);
 340                         continue;
 341
 342                 case iro_Const:
 343                         return get_Const_tarval(init);
 344
 345                 case iro_SymConst:
 346                         switch (get_SymConst_kind(init)) {
 347                         case symconst_type_size:
 348                                 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(init)), mode);
 349
 350                         case symconst_type_align:
 351                                 return new_tarval_from_long(get_type_alignment_bytes(get_SymConst_type(init)), mode);
 352
 353                         case symconst_ofs_ent:
 354                                 return new_tarval_from_long(get_entity_offset(get_SymConst_entity(init)), mode);
 355
 356                         case symconst_enum_const:
 357                                 return get_enumeration_value(get_SymConst_enum(init));
 358
 359                         default:
 360                                 return NULL;
 361                         }
 362
 363                 default:
 364                         return NULL;
 365                 }
 366         }
 367 }
 368
 369 /**
 370  * Dump an atomic value.
 371  *
 372  * @param env   the gas output environment
 373  * @param init  a node representing the atomic value (on the const code irg)
 374  */
 375 static void do_dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 376 {
 377         ir_mode *mode = get_irn_mode(init);
 378         int bytes     = get_mode_size_bytes(mode);
 379         tarval *tv;
 380         ir_entity *ent;
 381
 382         init = skip_Id(init);
 383
 384         switch (get_irn_opcode(init)) {
 385         case iro_Cast:
 386                 do_dump_atomic_init(env, get_Cast_op(init));
 387                 return;
 388
 389         case iro_Conv:
 390                 do_dump_atomic_init(env, get_Conv_op(init));
 391                 return;
 392
 393         case iro_Const:
 394                 tv = get_Const_tarval(init);
 395
 396                 /* it's a arithmetic value */
 397                 dump_arith_tarval(tv, bytes);
 398                 return;
 399
 400         case iro_SymConst:
 401                 switch (get_SymConst_kind(init)) {
 402                 case symconst_addr_name:
 403                         be_emit_ident(get_SymConst_name(init));
 404                         break;
 405
 406                 case symconst_addr_ent:
 407                         ent = get_SymConst_entity(init);
 408                         be_gas_emit_entity(ent);
 409                         break;
 410
 411                 case symconst_ofs_ent:
 412                         ent = get_SymConst_entity(init);
 413                         be_emit_irprintf("%d", get_entity_offset(ent));
 414                         break;
 415
 416                 case symconst_type_size:
 417                         be_emit_irprintf("%u", get_type_size_bytes(get_SymConst_type(init)));
 418                         break;
 419
 420                 case symconst_type_align:
 421                         be_emit_irprintf("%u", get_type_alignment_bytes(get_SymConst_type(init)));
 422                         break;
 423
 424                 case symconst_enum_const:
 425                         tv = get_enumeration_value(get_SymConst_enum(init));
 426                         dump_arith_tarval(tv, bytes);
 427                         break;
 428
 429                 default:
 430                         assert(!"dump_atomic_init(): don't know how to init from this SymConst");
 431                 }
 432                 return;
 433
 434         case iro_Add:
 435                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 436                         panic("Constant must be int or pointer for '+' to work");
 437                 }
 438                 do_dump_atomic_init(env, get_Add_left(init));
 439                 be_emit_cstring(" + ");
 440                 do_dump_atomic_init(env, get_Add_right(init));
 441                 return;
 442
 443         case iro_Sub:
 444                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 445                         panic("Constant must be int or pointer for '-' to work");
 446                 }
 447                 do_dump_atomic_init(env, get_Sub_left(init));
 448                 be_emit_cstring(" - ");
 449                 do_dump_atomic_init(env, get_Sub_right(init));
 450                 return;
 451
 452         case iro_Mul:
 453                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 454                         panic("Constant must be int or pointer for '*' to work");
 455                 }
 456                 do_dump_atomic_init(env, get_Mul_left(init));
 457                 be_emit_cstring(" * ");
 458                 do_dump_atomic_init(env, get_Mul_right(init));
 459                 return;
 460
 461         case iro_Unknown:
 462                 be_emit_cstring("0");
 463                 return;
 464
 465         default:
 466                 panic("dump_atomic_init(): unsupported IR-node %+F", init);
 467         }
 468 }
 469
 470 /**
 471  * Dumps the type for given size (.byte, .long, ...)
 472  *
 473  * @param size  the size in bytes
 474  */
 475 static void dump_size_type(size_t size) {
 476         switch (size) {
 477         case 1:
 478                 be_emit_cstring("\t.byte\t");
 479                 break;
 480
 481         case 2:
 482                 be_emit_cstring("\t.short\t");
 483                 break;
 484
 485         case 4:
 486                 be_emit_cstring("\t.long\t");
 487                 break;
 488
 489         case 8:
 490                 be_emit_cstring("\t.quad\t");
 491                 break;
 492
 493         case 10:
 494         case 12:
 495                 /* handled in arith */
 496                 break;
 497
 498         case 16:
 499                 be_emit_cstring("\t.octa\t");
 500                 break;
 501
 502         default:
 503                 panic("Try to dump a type with %u bytes", (unsigned)size);
 504         }
 505 }
 506
 507 /**
 508  * Emit an atomic value.
 509  *
 510  * @param env   the gas output environment
 511  * @param init  a node representing the atomic value (on the const code irg)
 512  */
 513 static void dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 514 {
 515         ir_mode *mode = get_irn_mode(init);
 516         int bytes     = get_mode_size_bytes(mode);
 517
 518         dump_size_type(bytes);
 519         do_dump_atomic_init(env, init);
 520         be_emit_char('\n');
 521         be_emit_write_line();
 522 }
 523
 524 /************************************************************************/
 525 /* Routines to dump global variables                                    */
 526 /************************************************************************/
 527
 528 static int initializer_is_string_const(const ir_initializer_t *initializer)
 529 {
 530         size_t i, len;
 531         int found_printable = 0;
 532
 533         if (initializer->kind != IR_INITIALIZER_COMPOUND)
 534                 return 0;
 535
 536         len = initializer->compound.n_initializers;
 537         if (len < 1)
 538                 return 0;
 539         for (i = 0; i < len; ++i) {
 540                 int               c;
 541                 tarval           *tv;
 542                 ir_mode          *mode;
 543                 ir_initializer_t *sub_initializer
 544                         = initializer->compound.initializers[i];
 545
 546                 if (sub_initializer->kind != IR_INITIALIZER_TARVAL)
 547                         return 0;
 548
 549                 tv   = sub_initializer->tarval.value;
 550                 mode = get_tarval_mode(tv);
 551
 552                 if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8)
 553                         return 0;
 554
 555                 c = get_tarval_long(tv);
 556                 if (isgraph(c) || isspace(c))
 557                         found_printable = 1;
 558                 else if (c != 0)
 559                         return 0;
 560
 561                 if (i == len - 1 && c != '\0')
 562                         return 0;
 563         }
 564
 565         return found_printable;
 566 }
 567
 568 /**
 569  * Determine if an entity is a string constant
 570  * @param ent The entity
 571  * @return 1 if it is a string constant, 0 otherwise
 572  */
 573 static int ent_is_string_const(const ir_entity *ent)
 574 {
 575         ir_type *type, *element_type;
 576         ir_mode *mode;
 577         int i, c, n;
 578
 579         type = get_entity_type(ent);
 580
 581         /* if it's an array */
 582         if (!is_Array_type(type))
 583                 return 0;
 584
 585         element_type = get_array_element_type(type);
 586
 587         /* and the array's element type is primitive */
 588         if (!is_Primitive_type(element_type))
 589                 return 0;
 590
 591         /* and the mode of the element type is an int of
 592          * the same size as the byte mode */
 593         mode = get_type_mode(element_type);
 594         if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8)
 595                 return 0;
 596
 597         if (ent->initializer != NULL) {
 598                 return initializer_is_string_const(ent->initializer);
 599         } else if (entity_has_compound_ent_values(ent)) {
 600                 int found_printable = 0;
 601                 /* if it contains only printable chars and a 0 at the end */
 602                 n = get_compound_ent_n_values(ent);
 603                 for (i = 0; i < n; ++i) {
 604                         ir_node *irn = get_compound_ent_value(ent, i);
 605                         if (! is_Const(irn))
 606                                 return 0;
 607
 608                         c = (int) get_tarval_long(get_Const_tarval(irn));
 609
 610                         if (isgraph(c) || isspace(c))
 611                                 found_printable = 1;
 612                         else if (c != 0)
 613                                 return 0;
 614
 615                         if (i == n - 1 && c != '\0')
 616                                 return 0;
 617                 }
 618                 return found_printable;
 619         }
 620
 621         return 0;
 622 }
 623
 624 /**
 625  * Dump a string constant.
 626  * No checks are made!!
 627  *
 628  * @param ent  The entity to dump.
 629  */
 630 static void dump_string_cst(const ir_entity *ent)
 631 {
 632         int      i, len;
 633         int      output_len;
 634         ir_type *type;
 635         int      type_size;
 636         int      remaining_space;
 637
 638         len        = get_compound_ent_n_values(ent);
 639         output_len = len;
 640         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 641                 be_emit_cstring("\t.ascii \"");
 642         } else {
 643                 be_emit_cstring("\t.string \"");
 644                 output_len -= 1;
 645         }
 646
 647         for (i = 0; i < output_len; ++i) {
 648                 ir_node *irn;
 649                 int c;
 650
 651                 irn = get_compound_ent_value(ent, i);
 652                 c = (int) get_tarval_long(get_Const_tarval(irn));
 653
 654                 switch (c) {
 655                 case '"' : be_emit_cstring("\\\""); break;
 656                 case '\n': be_emit_cstring("\\n"); break;
 657                 case '\r': be_emit_cstring("\\r"); break;
 658                 case '\t': be_emit_cstring("\\t"); break;
 659                 case '\\': be_emit_cstring("\\\\"); break;
 660                 default  :
 661                         if (isprint(c))
 662                                 be_emit_char(c);
 663                         else
 664                                 be_emit_irprintf("\\%o", c);
 665                         break;
 666                 }
 667         }
 668         be_emit_cstring("\"\n");
 669         be_emit_write_line();
 670
 671         type            = get_entity_type(ent);
 672         type_size       = get_type_size_bytes(type);
 673         remaining_space = type_size - len;
 674         assert(remaining_space >= 0);
 675         if (remaining_space > 0) {
 676                 be_emit_irprintf("\t.space\t%d\n", remaining_space);
 677         }
 678 }
 679
 680 static void dump_string_initializer(const ir_initializer_t *initializer)
 681 {
 682         size_t i, len;
 683
 684         len = initializer->compound.n_initializers;
 685         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 686                 be_emit_cstring("\t.ascii \"");
 687         } else {
 688                 be_emit_cstring("\t.string \"");
 689                 len -= 1;
 690         }
 691
 692         for (i = 0; i < len; ++i) {
 693                 const ir_initializer_t *sub_initializer
 694                         = get_initializer_compound_value(initializer, i);
 695
 696                 tarval *tv = get_initializer_tarval_value(sub_initializer);
 697                 int     c  = get_tarval_long(tv);
 698
 699                 switch (c) {
 700                 case '"' : be_emit_cstring("\\\""); break;
 701                 case '\n': be_emit_cstring("\\n"); break;
 702                 case '\r': be_emit_cstring("\\r"); break;
 703                 case '\t': be_emit_cstring("\\t"); break;
 704                 case '\\': be_emit_cstring("\\\\"); break;
 705                 default  :
 706                         if (isprint(c))
 707                                 be_emit_char(c);
 708                         else
 709                                 be_emit_irprintf("\\%o", c);
 710                         break;
 711                 }
 712         }
 713         be_emit_cstring("\"\n");
 714         be_emit_write_line();
 715 }
 716
 717 enum normal_or_bitfield_kind {
 718         NORMAL = 0,
 719         TARVAL,
 720         BITFIELD
 721 };
 722
 723 typedef struct {
 724         enum normal_or_bitfield_kind kind;
 725         union {
 726                 ir_node       *value;
 727                 tarval        *tarval;
 728                 unsigned char  bf_val;
 729         } v;
 730 } normal_or_bitfield;
 731
 732 static int is_type_variable_size(ir_type *type)
 733 {
 734         (void) type;
 735         /* TODO */
 736         return 0;
 737 }
 738
 739 static size_t get_initializer_size(const ir_initializer_t *initializer,
 740                                    ir_type *type)
 741 {
 742         switch (get_initializer_kind(initializer)) {
 743         case IR_INITIALIZER_TARVAL:
 744                 assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type));
 745                 return get_type_size_bytes(type);
 746         case IR_INITIALIZER_CONST:
 747         case IR_INITIALIZER_NULL:
 748                 return get_type_size_bytes(type);
 749         case IR_INITIALIZER_COMPOUND:
 750                 if (!is_type_variable_size(type)) {
 751                         return get_type_size_bytes(type);
 752                 } else {
 753                         unsigned n_entries
 754                                 = get_initializer_compound_n_entries(initializer);
 755                         unsigned i;
 756                         unsigned initializer_size = get_type_size_bytes(type);
 757                         for (i = 0; i < n_entries; ++i) {
 758                                 ir_entity *entity = get_compound_member(type, i);
 759                                 ir_type   *type   = get_entity_type(entity);
 760
 761                                 const ir_initializer_t *sub_initializer
 762                                         = get_initializer_compound_value(initializer, i);
 763
 764                                 unsigned offset = get_entity_offset(entity);
 765                                 unsigned size   = get_initializer_size(sub_initializer, type);
 766
 767                                 if (offset + size > initializer_size) {
 768                                         initializer_size = offset + size;
 769                                 }
 770                         }
 771                         return initializer_size;
 772                 }
 773         }
 774
 775         panic("found invalid initializer");
 776 }
 777
 778 #ifndef NDEBUG
 779 static normal_or_bitfield *glob_vals;
 780 static size_t              max_vals;
 781 #endif
 782
 783 static void dump_bitfield(normal_or_bitfield *vals, size_t offset_bits,
 784                           const ir_initializer_t *initializer, ir_type *type)
 785 {
 786         unsigned char  last_bits = 0;
 787         ir_mode       *mode      = get_type_mode(type);
 788         tarval        *tv        = NULL;
 789         unsigned char  curr_bits;
 790         int            value_len;
 791         int            j;
 792
 793         switch (get_initializer_kind(initializer)) {
 794         case IR_INITIALIZER_NULL:
 795                 return;
 796         case IR_INITIALIZER_TARVAL:
 797                 tv = get_initializer_tarval_value(initializer);
 798                 break;
 799         case IR_INITIALIZER_CONST: {
 800                 ir_node *node = get_initializer_const_value(initializer);
 801                 if (!is_Const(node)) {
 802                         panic("bitfield initializer not a Const node");
 803                 }
 804                 tv = get_Const_tarval(node);
 805                 break;
 806         }
 807         case IR_INITIALIZER_COMPOUND:
 808                 panic("bitfield initializer is compound");
 809         }
 810         if (tv == NULL) {
 811                 panic("Couldn't get numeric value for bitfield initializer");
 812         }
 813         tv = tarval_convert_to(tv, get_type_mode(type));
 814
 815         /* normalize offset */
 816         vals        += offset_bits >> 3;
 817         offset_bits &= 7;
 818         value_len    = get_mode_size_bits(mode);
 819
 820         /* combine bits with existing bits */
 821         for (j = 0; value_len + (int) offset_bits > 0; ++j) {
 822                 assert((size_t) (vals - glob_vals) + j < max_vals);
 823                 assert(vals[j].kind == BITFIELD ||
 824                                 (vals[j].kind == NORMAL && vals[j].v.value == NULL));
 825                 vals[j].kind = BITFIELD;
 826                 curr_bits    = get_tarval_sub_bits(tv, j);
 827                 vals[j].v.bf_val
 828                         |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
 829                 value_len -= 8;
 830                 last_bits = curr_bits;
 831         }
 832 }
 833
 834 static void dump_ir_initializer(normal_or_bitfield *vals,
 835                                 const ir_initializer_t *initializer,
 836                                 ir_type *type)
 837 {
 838         assert((size_t) (vals - glob_vals) < max_vals);
 839
 840         switch (get_initializer_kind(initializer)) {
 841         case IR_INITIALIZER_NULL:
 842                 return;
 843         case IR_INITIALIZER_TARVAL: {
 844                 size_t i;
 845
 846                 assert(vals->kind != BITFIELD);
 847                 vals->kind     = TARVAL;
 848                 vals->v.tarval = get_initializer_tarval_value(initializer);
 849                 assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval));
 850                 for (i = 1; i < get_type_size_bytes(type); ++i) {
 851                         vals[i].kind    = NORMAL;
 852                         vals[i].v.value = NULL;
 853                 }
 854                 return;
 855         }
 856         case IR_INITIALIZER_CONST: {
 857                 size_t i;
 858
 859                 assert(vals->kind != BITFIELD);
 860                 vals->kind    = NORMAL;
 861                 vals->v.value = get_initializer_const_value(initializer);
 862                 for (i = 1; i < get_type_size_bytes(type); ++i) {
 863                         vals[i].kind    = NORMAL;
 864                         vals[i].v.value = NULL;
 865                 }
 866                 return;
 867         }
 868         case IR_INITIALIZER_COMPOUND: {
 869                 size_t i = 0;
 870                 size_t n = get_initializer_compound_n_entries(initializer);
 871
 872                 if (is_Array_type(type)) {
 873                         ir_type *element_type = get_array_element_type(type);
 874                         size_t   skip         = get_type_size_bytes(element_type);
 875                         size_t   alignment    = get_type_alignment_bytes(element_type);
 876                         size_t   misalign     = skip % alignment;
 877                         if (misalign != 0) {
 878                                 skip += alignment - misalign;
 879                         }
 880
 881                         for (i = 0; i < n; ++i) {
 882                                 ir_initializer_t *sub_initializer
 883                                         = get_initializer_compound_value(initializer, i);
 884
 885                                 dump_ir_initializer(vals, sub_initializer, element_type);
 886
 887                                 vals += skip;
 888                         }
 889                 } else {
 890                         size_t n_members, i;
 891                         assert(is_compound_type(type));
 892                         n_members = get_compound_n_members(type);
 893                         for (i = 0; i < n_members; ++i) {
 894                                 ir_entity        *member    = get_compound_member(type, i);
 895                                 size_t            offset    = get_entity_offset(member);
 896                                 ir_type          *subtype   = get_entity_type(member);
 897                                 ir_mode          *mode      = get_type_mode(subtype);
 898                                 ir_initializer_t *sub_initializer;
 899
 900                                 assert(i < get_initializer_compound_n_entries(initializer));
 901                                 sub_initializer
 902                                         = get_initializer_compound_value(initializer, i);
 903
 904                                 if (mode != NULL) {
 905                                         size_t offset_bits
 906                                                 = get_entity_offset_bits_remainder(member);
 907                                         size_t value_len   = get_mode_size_bits(mode);
 908
 909                                         if (offset_bits != 0 ||
 910                                                 (value_len != 8 && value_len != 16 && value_len != 32
 911                                                  && value_len != 64)) {
 912                                                 dump_bitfield(&vals[offset], offset_bits,
 913                                                               sub_initializer, subtype);
 914                                                 continue;
 915                                         }
 916                                 }
 917
 918                                 dump_ir_initializer(&vals[offset], sub_initializer, subtype);
 919                         }
 920                 }
 921
 922                 return;
 923         }
 924         }
 925         panic("invalid ir_initializer kind found");
 926 }
 927
 928 static void dump_initializer(be_gas_decl_env_t *env, const ir_entity *entity)
 929 {
 930         const ir_initializer_t *initializer = entity->initializer;
 931         ir_type                *type;
 932         normal_or_bitfield     *vals;
 933         size_t                  size;
 934         size_t                  k;
 935
 936         if (initializer_is_string_const(initializer)) {
 937                 dump_string_initializer(initializer);
 938                 return;
 939         }
 940
 941         type = get_entity_type(entity);
 942         size = get_initializer_size(initializer, type);
 943
 944         if (size == 0)
 945                 return;
 946
 947         /*
 948          * In the worst case, every initializer allocates one byte.
 949          * Moreover, initializer might be big, do not allocate on stack.
 950          */
 951         vals = XMALLOCNZ(normal_or_bitfield, size);
 952
 953 #ifndef NDEBUG
 954         glob_vals = vals;
 955         max_vals  = size;
 956 #endif
 957
 958         dump_ir_initializer(vals, initializer, type);
 959
 960         /* now write values sorted */
 961         for (k = 0; k < size; ) {
 962                 int space     = 0;
 963                 int elem_size = 1;
 964                 if (vals[k].kind == NORMAL) {
 965                         if (vals[k].v.value != NULL) {
 966                                 dump_atomic_init(env, vals[k].v.value);
 967                                 elem_size = get_mode_size_bytes(get_irn_mode(vals[k].v.value));
 968                         } else {
 969                                 elem_size = 0;
 970                         }
 971                 } else if (vals[k].kind == TARVAL) {
 972                         tarval *tv   = vals[k].v.tarval;
 973                         size_t  size = get_mode_size_bytes(get_tarval_mode(tv));
 974
 975                         assert(tv != NULL);
 976
 977                         elem_size = size;
 978                         dump_size_type(size);
 979                         dump_arith_tarval(tv, size);
 980                         be_emit_char('\n');
 981                         be_emit_write_line();
 982                 } else {
 983                         assert(vals[k].kind == BITFIELD);
 984                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
 985                         be_emit_write_line();
 986                 }
 987
 988                 k += elem_size;
 989                 while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
 990                         ++space;
 991                         ++k;
 992                 }
 993
 994                 /* a gap */
 995                 if (space > 0) {
 996                         be_emit_irprintf("\t.space\t%d\n", space);
 997                         be_emit_write_line();
 998                 }
 999         }
1000         xfree(vals);
1001 }
1002
1003 static void dump_compound_graph_init(be_gas_decl_env_t *env,
1004                                      const ir_entity *ent)
1005 {
1006         normal_or_bitfield *vals;
1007         int i, j, n;
1008         unsigned k, last_ofs;
1009
1010         if (ent_is_string_const(ent)) {
1011                 dump_string_cst(ent);
1012                 return;
1013         }
1014
1015         n = get_compound_ent_n_values(ent);
1016
1017         /* Find the initializer size. Sorrily gcc support a nasty feature:
1018            The last field of a compound may be a flexible array. This allows
1019            initializers bigger than the type size. */
1020         last_ofs = get_type_size_bytes(get_entity_type(ent));
1021         for (i = 0; i < n; ++i) {
1022                 unsigned offset         = get_compound_ent_value_offset_bytes(ent, i);
1023                 unsigned bits_remainder = get_compound_ent_value_offset_bit_remainder(ent, i);
1024                 ir_node  *value         = get_compound_ent_value(ent, i);
1025                 unsigned value_len      = get_mode_size_bits(get_irn_mode(value));
1026
1027                 offset += (value_len + bits_remainder + 7) >> 3;
1028
1029                 if (offset > last_ofs) {
1030                         last_ofs = offset;
1031                 }
1032         }
1033
1034         /*
1035          * In the worst case, every initializer allocates one byte.
1036          * Moreover, initializer might be big, do not allocate on stack.
1037          */
1038         vals = XMALLOCNZ(normal_or_bitfield, last_ofs);
1039
1040         /* collect the values and store them at the offsets */
1041         for (i = 0; i < n; ++i) {
1042                 unsigned offset      = get_compound_ent_value_offset_bytes(ent, i);
1043                 int      offset_bits = get_compound_ent_value_offset_bit_remainder(ent, i);
1044                 ir_node  *value      = get_compound_ent_value(ent, i);
1045                 int      value_len   = get_mode_size_bits(get_irn_mode(value));
1046
1047                 assert(offset_bits >= 0);
1048
1049                 if (offset_bits != 0 ||
1050                                 (value_len != 8 && value_len != 16 && value_len != 32 && value_len != 64)) {
1051                         tarval *tv = get_atomic_init_tv(value);
1052                         unsigned char curr_bits, last_bits = 0;
1053                         if (tv == NULL) {
1054                                 panic("Couldn't get numeric value for bitfield initializer '%s'",
1055                                                 get_entity_ld_name(ent));
1056                         }
1057                         /* normalize offset */
1058                         offset += offset_bits >> 3;
1059                         offset_bits &= 7;
1060
1061                         for (j = 0; value_len + offset_bits > 0; ++j) {
1062                                 assert(offset + j < last_ofs);
1063                                 assert(vals[offset + j].kind == BITFIELD || vals[offset + j].v.value == NULL);
1064                                 vals[offset + j].kind = BITFIELD;
1065                                 curr_bits = get_tarval_sub_bits(tv, j);
1066                                 vals[offset + j].v.bf_val |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
1067                                 value_len -= 8;
1068                                 last_bits = curr_bits;
1069                         }
1070                 } else {
1071                         int i;
1072
1073                         assert(offset < last_ofs);
1074                         assert(vals[offset].kind == NORMAL);
1075                         for (i = 1; i < value_len / 8; ++i) {
1076                                 assert(vals[offset + i].v.value == NULL);
1077                         }
1078                         vals[offset].v.value = value;
1079                 }
1080         }
1081
1082         /* now write them sorted */
1083         for (k = 0; k < last_ofs; ) {
1084                 int space = 0, skip = 0;
1085                 if (vals[k].kind == NORMAL) {
1086                         if (vals[k].v.value != NULL) {
1087                                 dump_atomic_init(env, vals[k].v.value);
1088                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
1089                         } else {
1090                                 space = 1;
1091                         }
1092                 } else {
1093                         assert(vals[k].kind == BITFIELD);
1094                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1095                 }
1096
1097                 ++k;
1098                 while (k < last_ofs && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1099                         ++space;
1100                         ++k;
1101                 }
1102                 space -= skip;
1103                 assert(space >= 0);
1104
1105                 /* a gap */
1106                 if (space > 0) {
1107                         be_emit_irprintf("\t.space\t%d\n", space);
1108                         be_emit_write_line();
1109                 }
1110         }
1111         xfree(vals);
1112 }
1113
1114 static void emit_align(unsigned p2alignment)
1115 {
1116         be_emit_irprintf("\t.p2align\t%u\n", log2_floor(p2alignment));
1117         be_emit_write_line();
1118 }
1119
1120 static unsigned get_effective_entity_alignment(const ir_entity *entity)
1121 {
1122         unsigned alignment = get_entity_alignment(entity);
1123         if (alignment == 0) {
1124                 ir_type *type = get_entity_type(entity);
1125                 alignment     = get_type_alignment_bytes(type);
1126         }
1127         return alignment;
1128 }
1129
1130 static be_gas_section_t determine_section(be_gas_decl_env_t *env,
1131                                           const ir_entity *entity)
1132 {
1133         ir_type *owner = get_entity_owner(entity);
1134
1135         if (owner == get_segment_type(IR_SEGMENT_GLOBAL)) {
1136                 ir_linkage linkage = get_entity_linkage(entity);
1137                 if (linkage & IR_LINKAGE_CONSTANT) {
1138                         /* mach-o is the only one with a cstring section */
1139                         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O
1140                                         && ent_is_string_const(entity))
1141                                 return GAS_SECTION_CSTRING;
1142
1143                         return GAS_SECTION_RODATA;
1144                 }
1145                 if (!entity_has_definition(entity))
1146                         return GAS_SECTION_BSS;
1147
1148                 return GAS_SECTION_DATA;
1149
1150         } else if (owner == env->main_env->pic_symbols_type) {
1151                 return GAS_SECTION_PIC_SYMBOLS;
1152         } else if (owner == env->main_env->pic_trampolines_type) {
1153                 return GAS_SECTION_PIC_TRAMPOLINES;
1154         } else if (owner == get_segment_type(IR_SEGMENT_CONSTRUCTORS)) {
1155                 return GAS_SECTION_CONSTRUCTORS;
1156         } else if (owner == get_segment_type(IR_SEGMENT_DESTRUCTORS)) {
1157                 return GAS_SECTION_DESTRUCTORS;
1158         } else if (owner == get_segment_type(IR_SEGMENT_THREAD_LOCAL)) {
1159                 return GAS_SECTION_TLS;
1160         }
1161
1162         panic("Couldn't determine section for %+F?!?", entity);
1163 }
1164
1165 static void emit_common(const ir_entity *ent)
1166 {
1167         const char *name      = get_entity_ld_name(ent);
1168         unsigned    size      = get_type_size_bytes(get_entity_type(ent));
1169         unsigned    alignment = get_effective_entity_alignment(ent);
1170
1171         switch (be_gas_object_file_format) {
1172         case OBJECT_FILE_FORMAT_MACH_O:
1173                 be_emit_irprintf("\t.comm %s,%u,%u\n", name, size,
1174                                  log2_floor(alignment));
1175                 be_emit_write_line();
1176                 return;
1177         case OBJECT_FILE_FORMAT_ELF:
1178                 be_emit_irprintf("\t.comm %s,%u,%u\n", name, size, alignment);
1179                 be_emit_write_line();
1180                 return;
1181         case OBJECT_FILE_FORMAT_COFF:
1182                 be_emit_irprintf("\t.comm %s,%u # %u\n", name, size, alignment);
1183                 be_emit_write_line();
1184                 return;
1185         }
1186         panic("invalid object file format");
1187 }
1188
1189 static void dump_indirect_symbol(const ir_entity *entity, be_gas_section_t section)
1190 {
1191         /* we can only do PIC code on macho so far */
1192         assert(be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O);
1193
1194         be_emit_ident(get_entity_ld_ident(entity));
1195         be_emit_cstring(":\n");
1196         be_emit_write_line();
1197         be_emit_cstring("\t.indirect_symbol ");
1198         be_emit_ident(get_entity_ident(entity));
1199         be_emit_char('\n');
1200         be_emit_write_line();
1201         if (section == GAS_SECTION_PIC_TRAMPOLINES) {
1202                 be_emit_cstring("\thlt ; hlt ; hlt ; hlt ; hlt\n");
1203                 be_emit_write_line();
1204         } else {
1205                 assert(section == GAS_SECTION_PIC_SYMBOLS);
1206                 be_emit_cstring("\t.long 0\n");
1207                 be_emit_write_line();
1208         }
1209 }
1210
1211 /**
1212  * Dump a global entity.
1213  *
1214  * @param env  the gas output environment
1215  * @param ent  the entity to be dumped
1216  */
1217 static void dump_global(be_gas_decl_env_t *env, const ir_entity *ent)
1218 {
1219         ir_type          *type           = get_entity_type(ent);
1220         ident            *ld_ident       = get_entity_ld_ident(ent);
1221         unsigned          alignment      = get_effective_entity_alignment(ent);
1222         be_gas_section_t  section        = determine_section(env, ent);
1223
1224         /* we already emitted all methods. Except for the trampolines which
1225          * the assembler/linker generates */
1226         if (is_Method_type(type) && section != GAS_SECTION_PIC_TRAMPOLINES) {
1227                 return;
1228         }
1229         /* block labels are already emittet in the code */
1230         if (type == firm_code_type)
1231                 return;
1232
1233         be_dbg_variable(ent);
1234
1235         /* nothing to do for externally defined values */
1236         if (get_entity_visibility(ent) == ir_visibility_external)
1237                 return;
1238
1239         if (!is_po2(alignment))
1240                 panic("alignment not a power of 2");
1241
1242         if (section == GAS_SECTION_BSS &&
1243                         (get_entity_linkage(ent) & IR_LINKAGE_MERGE)) {
1244                 if (get_entity_visibility(ent) != ir_visibility_default) {
1245                         panic("merge link semantic not supported for local/extern entities");
1246                 }
1247                 emit_common(ent);
1248                 return;
1249         }
1250
1251         be_gas_emit_switch_section(section);
1252
1253         if (section == GAS_SECTION_PIC_TRAMPOLINES
1254                         || section == GAS_SECTION_PIC_SYMBOLS) {
1255                 dump_indirect_symbol(ent, section);
1256                 return;
1257         }
1258
1259         /* alignment */
1260         if (alignment > 1) {
1261                 emit_align(alignment);
1262         }
1263         emit_entity_visibility(ent);
1264         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_ELF
1265                         && be_gas_emit_types) {
1266                 be_emit_cstring("\t.type\t");
1267                 be_emit_ident(ld_ident);
1268                 be_emit_cstring(", ");
1269                 be_emit_char(be_gas_elf_type_char);
1270                 be_emit_cstring("object\n\t.size\t");
1271                 be_emit_ident(ld_ident);
1272                 be_emit_irprintf(", %u\n", get_type_size_bytes(type));
1273         }
1274         be_emit_ident(ld_ident);
1275         be_emit_cstring(":\n");
1276         be_emit_write_line();
1277
1278         if (ent->initializer != NULL) {
1279                 dump_initializer(env, ent);
1280         } else if(entity_has_compound_ent_values(ent)) {
1281                 dump_compound_graph_init(env, ent);
1282         } else {
1283                 /* uninitialized */
1284                 be_emit_irprintf("\t.space %u\n", get_type_size_bytes(type));
1285                 be_emit_write_line();
1286         }
1287 }
1288
1289 /**
1290  * Dumps declarations of global variables and the initialization code.
1291  *
1292  * @param gt                a global like type, either the global or the TLS one
1293  * @param env               an environment
1294  */
1295 static void be_gas_dump_globals(ir_type *gt, be_gas_decl_env_t *env)
1296 {
1297         int i, n = get_compound_n_members(gt);
1298
1299         for (i = 0; i < n; i++) {
1300                 ir_entity *ent = get_compound_member(gt, i);
1301                 dump_global(env, ent);
1302         }
1303 }
1304
1305 /************************************************************************/
1306
1307 /* Generate all entities. */
1308 void be_gas_emit_decls(const be_main_env_t *main_env)
1309 {
1310         be_gas_decl_env_t env;
1311         memset(&env, 0, sizeof(env));
1312
1313         /* dump global type */
1314         env.main_env = main_env;
1315         env.section  = (be_gas_section_t) -1;
1316
1317         be_gas_dump_globals(get_glob_type(), &env);
1318         be_gas_dump_globals(get_tls_type(), &env);
1319         be_gas_dump_globals(get_segment_type(IR_SEGMENT_CONSTRUCTORS), &env);
1320         be_gas_dump_globals(get_segment_type(IR_SEGMENT_DESTRUCTORS), &env);
1321         be_gas_dump_globals(main_env->pic_symbols_type, &env);
1322         be_gas_dump_globals(main_env->pic_trampolines_type, &env);
1323
1324         /**
1325          * ".subsections_via_symbols marks object files which are OK to divide
1326          * their section contents into individual blocks".
1327          * From my understanding this means no label points in the middle of an
1328          * object which we want to address as a whole. Firm code should be fine
1329          * with this.
1330          */
1331         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
1332                 be_emit_cstring("\t.subsections_via_symbols\n");
1333                 be_emit_write_line();
1334         }
1335 }