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 "pdeq.h"
  41 #include "entity_t.h"
  42 #include "error.h"
  43
  44 #include "be_t.h"
  45 #include "beemitter.h"
  46 #include "be_dbgout.h"
  47
  48 /** by default, we generate assembler code for the Linux gas */
  49 object_file_format_t  be_gas_object_file_format = OBJECT_FILE_FORMAT_ELF;
  50 bool                  be_gas_emit_types         = true;
  51 char                  be_gas_elf_type_char = '@';
  52
  53 static be_gas_section_t current_section = (be_gas_section_t) -1;
  54
  55 /**
  56  * Return the pseudo-instruction to be issued for a section switch
  57  * depending on the current flavour.
  58  *
  59  * @param section  the section to switch to
  60  *
  61  * @return  the pseudo-instruction
  62  */
  63 static const char *get_section_name(be_gas_section_t section)
  64 {
  65         static const char *text[OBJECT_FILE_FORMAT_LAST+1][GAS_SECTION_LAST+1] = {
  66                 { /* OBJECT_FILE_FORMAT_ELF */
  67                         ".section\t.text",
  68                         ".section\t.data",
  69                         ".section\t.rodata",
  70                         ".section\t.bss",
  71                         ".section\t.tbss,\"awT\",@nobits",
  72                         ".section\t.ctors,\"aw\",@progbits",
  73                         ".section\t.dtors,\"aw\",@progbits",
  74                         NULL, /* no cstring section */
  75                         NULL,
  76                         NULL
  77                 },
  78                 { /* OBJECT_FILE_FORMAT_COFF */
  79                         ".section\t.text",
  80                         ".section\t.data",
  81                         ".section .rdata,\"dr\"",
  82                         ".section\t.bss",
  83                         ".section\t.tbss,\"awT\",@nobits",
  84                         ".section\t.ctors,\"w\"",
  85                         ".section\t.dtors,\"w\"",
  86                         NULL,
  87                         NULL,
  88                         NULL
  89                 },
  90                 { /* OBJECT_FILE_FORMAT_MACH_O */
  91                         ".text",
  92                         ".data",
  93                         ".const",
  94                         ".data",
  95                         NULL,             /* TLS is not supported on Mach-O */
  96                         ".mod_init_func",
  97                         NULL,             /* are there destructors on mach-o? */
  98                         ".cstring",
  99                         ".section\t__IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_instructions,5",
 100                         ".section\t__IMPORT,__pointers,non_lazy_symbol_pointers"
 101                 }
 102         };
 103
 104         assert((int) be_gas_object_file_format >= 0
 105                         && be_gas_object_file_format <= OBJECT_FILE_FORMAT_LAST);
 106         assert((int) section >= 0 && section <= GAS_SECTION_LAST);
 107         return text[be_gas_object_file_format][section];
 108 }
 109
 110 void be_gas_emit_switch_section(be_gas_section_t section)
 111 {
 112         if (current_section == section)
 113                 return;
 114
 115         be_emit_char('\t');
 116         be_emit_string(get_section_name(section));
 117         be_emit_char('\n');
 118         be_emit_write_line();
 119         current_section = section;
 120 }
 121
 122 static void emit_entity_visibility(const ir_entity *entity)
 123 {
 124         ir_linkage linkage = get_entity_linkage(entity);
 125
 126         if (! (linkage & IR_LINKAGE_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_linkage(entity) & IR_LINKAGE_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         waitq               *worklist;           /**< A worklist we use to place not yet handled entities on. */
 227         const be_main_env_t       *main_env;
 228 } be_gas_decl_env_t;
 229
 230 /************************************************************************/
 231
 232 /**
 233  * Output a tarval.
 234  *
 235  * @param tv     the tarval
 236  * @param bytes  the width of the tarvals value in bytes
 237  */
 238 static void dump_arith_tarval(tarval *tv, int bytes)
 239 {
 240         switch (bytes) {
 241         case 1:
 242                 be_emit_irprintf("0x%02x", get_tarval_sub_bits(tv, 0));
 243                 return;
 244
 245         case 2:
 246                 be_emit_irprintf("0x%02x%02x", get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 247                 return;
 248
 249         case 4:
 250                 be_emit_irprintf("0x%02x%02x%02x%02x",
 251                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 252                 return;
 253
 254         case 8:
 255                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x",
 256                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6), get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
 257                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 258                 return;
 259
 260         case 12:
 261                 /* Beware: Mixed endian output!  One little endian number emitted as
 262                  * three longs.  Each long initializer is written in big endian. */
 263                 be_emit_irprintf(
 264                         "\t.long\t0x%02x%02x%02x%02x\n"
 265                         "\t.long\t0x%02x%02x%02x%02x\n"
 266                         "\t.long\t0x%02x%02x%02x%02x",
 267                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
 268                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0),
 269                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
 270                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
 271                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 272                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8)
 273                 );
 274                 return;
 275
 276         case 16:
 277                 be_emit_irprintf(
 278                         "\t.long\t0x%02x%02x%02x%02x0x%02x%02x%02x%02x0x%02x%02x%02x%02x0x%02x%02x%02x%02x",
 279                         get_tarval_sub_bits(tv, 15), get_tarval_sub_bits(tv, 16),
 280                         get_tarval_sub_bits(tv, 13), get_tarval_sub_bits(tv, 12),
 281                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 282                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8),
 283                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
 284                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
 285                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
 286                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0)
 287                 );
 288                 return;
 289         }
 290
 291         panic("Can't dump a tarval with %d bytes", bytes);
 292 }
 293
 294 /**
 295  * Return the label prefix for labeled blocks.
 296  */
 297 const char *be_gas_block_label_prefix(void)
 298 {
 299         return ".LG";
 300 }
 301
 302 /**
 303  * Return the label prefix for labeled instructions.
 304  */
 305 const char *be_gas_insn_label_prefix(void)
 306 {
 307         return ".LE";
 308 }
 309
 310 void be_gas_emit_entity(ir_entity *entity)
 311 {
 312         if (entity->type == firm_code_type) {
 313                 ir_label_t label = get_entity_label(entity);
 314                 be_emit_string(be_gas_block_label_prefix());
 315                 be_emit_irprintf("%lu", label);
 316         } else {
 317                 be_emit_ident(get_entity_ld_ident(entity));
 318         }
 319 }
 320
 321 /**
 322  * Return the tarval of an atomic initializer.
 323  *
 324  * @param init  a node representing the initializer (on the const code irg)
 325  *
 326  * @return the tarval
 327  */
 328 static tarval *get_atomic_init_tv(ir_node *init)
 329 {
 330         for (;;) {
 331                 ir_mode *mode = get_irn_mode(init);
 332
 333                 switch (get_irn_opcode(init)) {
 334
 335                 case iro_Cast:
 336                         init = get_Cast_op(init);
 337                         continue;
 338
 339                 case iro_Conv:
 340                         init = get_Conv_op(init);
 341                         continue;
 342
 343                 case iro_Const:
 344                         return get_Const_tarval(init);
 345
 346                 case iro_SymConst:
 347                         switch (get_SymConst_kind(init)) {
 348                         case symconst_type_size:
 349                                 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(init)), mode);
 350
 351                         case symconst_type_align:
 352                                 return new_tarval_from_long(get_type_alignment_bytes(get_SymConst_type(init)), mode);
 353
 354                         case symconst_ofs_ent:
 355                                 return new_tarval_from_long(get_entity_offset(get_SymConst_entity(init)), mode);
 356
 357                         case symconst_enum_const:
 358                                 return get_enumeration_value(get_SymConst_enum(init));
 359
 360                         default:
 361                                 return NULL;
 362                         }
 363
 364                 default:
 365                         return NULL;
 366                 }
 367         }
 368 }
 369
 370 /**
 371  * Dump an atomic value.
 372  *
 373  * @param env   the gas output environment
 374  * @param init  a node representing the atomic value (on the const code irg)
 375  */
 376 static void do_dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 377 {
 378         ir_mode *mode = get_irn_mode(init);
 379         int bytes     = get_mode_size_bytes(mode);
 380         tarval *tv;
 381         ir_entity *ent;
 382
 383         init = skip_Id(init);
 384
 385         switch (get_irn_opcode(init)) {
 386         case iro_Cast:
 387                 do_dump_atomic_init(env, get_Cast_op(init));
 388                 return;
 389
 390         case iro_Conv:
 391                 do_dump_atomic_init(env, get_Conv_op(init));
 392                 return;
 393
 394         case iro_Const:
 395                 tv = get_Const_tarval(init);
 396
 397                 /* it's a arithmetic value */
 398                 dump_arith_tarval(tv, bytes);
 399                 return;
 400
 401         case iro_SymConst:
 402                 switch (get_SymConst_kind(init)) {
 403                 case symconst_addr_name:
 404                         be_emit_ident(get_SymConst_name(init));
 405                         break;
 406
 407                 case symconst_addr_ent:
 408                         ent = get_SymConst_entity(init);
 409                         if (!is_entity_backend_marked(ent)) {
 410                                 waitq_put(env->worklist, ent);
 411                                 set_entity_backend_marked(ent, 1);
 412                         }
 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                 /* handled in arith */
 501                 break;
 502
 503         case 16:
 504                 be_emit_cstring("\t.octa\t");
 505                 break;
 506
 507         default:
 508                 panic("Try to dump a type with %u bytes", (unsigned)size);
 509         }
 510 }
 511
 512 /**
 513  * Emit an atomic value.
 514  *
 515  * @param env   the gas output environment
 516  * @param init  a node representing the atomic value (on the const code irg)
 517  */
 518 static void dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 519 {
 520         ir_mode *mode = get_irn_mode(init);
 521         int bytes     = get_mode_size_bytes(mode);
 522
 523         dump_size_type(bytes);
 524         do_dump_atomic_init(env, init);
 525         be_emit_char('\n');
 526         be_emit_write_line();
 527 }
 528
 529 /************************************************************************/
 530 /* Routines to dump global variables                                    */
 531 /************************************************************************/
 532
 533 static int initializer_is_string_const(const ir_initializer_t *initializer)
 534 {
 535         size_t i, len;
 536         int found_printable = 0;
 537
 538         if (initializer->kind != IR_INITIALIZER_COMPOUND)
 539                 return 0;
 540
 541         len = initializer->compound.n_initializers;
 542         if (len < 1)
 543                 return 0;
 544         for (i = 0; i < len; ++i) {
 545                 int               c;
 546                 tarval           *tv;
 547                 ir_mode          *mode;
 548                 ir_initializer_t *sub_initializer
 549                         = initializer->compound.initializers[i];
 550
 551                 if (sub_initializer->kind != IR_INITIALIZER_TARVAL)
 552                         return 0;
 553
 554                 tv   = sub_initializer->tarval.value;
 555                 mode = get_tarval_mode(tv);
 556
 557                 if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8)
 558                         return 0;
 559
 560                 c = get_tarval_long(tv);
 561                 if (isgraph(c) || isspace(c))
 562                         found_printable = 1;
 563                 else if (c != 0)
 564                         return 0;
 565
 566                 if (i == len - 1 && c != '\0')
 567                         return 0;
 568         }
 569
 570         return found_printable;
 571 }
 572
 573 /**
 574  * Determine if an entity is a string constant
 575  * @param ent The entity
 576  * @return 1 if it is a string constant, 0 otherwise
 577  */
 578 static int ent_is_string_const(const ir_entity *ent)
 579 {
 580         ir_type *type, *element_type;
 581         ir_mode *mode;
 582         int i, c, n;
 583
 584         type = get_entity_type(ent);
 585
 586         /* if it's an array */
 587         if (!is_Array_type(type))
 588                 return 0;
 589
 590         element_type = get_array_element_type(type);
 591
 592         /* and the array's element type is primitive */
 593         if (!is_Primitive_type(element_type))
 594                 return 0;
 595
 596         /* and the mode of the element type is an int of
 597          * the same size as the byte mode */
 598         mode = get_type_mode(element_type);
 599         if (!mode_is_int(mode) || get_mode_size_bits(mode) != 8)
 600                 return 0;
 601
 602         if (ent->initializer != NULL) {
 603                 return initializer_is_string_const(ent->initializer);
 604         } else if (entity_has_compound_ent_values(ent)) {
 605                 int found_printable = 0;
 606                 /* if it contains only printable chars and a 0 at the end */
 607                 n = get_compound_ent_n_values(ent);
 608                 for (i = 0; i < n; ++i) {
 609                         ir_node *irn = get_compound_ent_value(ent, i);
 610                         if (! is_Const(irn))
 611                                 return 0;
 612
 613                         c = (int) get_tarval_long(get_Const_tarval(irn));
 614
 615                         if (isgraph(c) || isspace(c))
 616                                 found_printable = 1;
 617                         else if (c != 0)
 618                                 return 0;
 619
 620                         if (i == n - 1 && c != '\0')
 621                                 return 0;
 622                 }
 623                 return found_printable;
 624         }
 625
 626         return 0;
 627 }
 628
 629 /**
 630  * Dump a string constant.
 631  * No checks are made!!
 632  *
 633  * @param ent  The entity to dump.
 634  */
 635 static void dump_string_cst(const ir_entity *ent)
 636 {
 637         int      i, len;
 638         int      output_len;
 639         ir_type *type;
 640         int      type_size;
 641         int      remaining_space;
 642
 643         len        = get_compound_ent_n_values(ent);
 644         output_len = len;
 645         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 646                 be_emit_cstring("\t.ascii \"");
 647         } else {
 648                 be_emit_cstring("\t.string \"");
 649                 output_len -= 1;
 650         }
 651
 652         for (i = 0; i < output_len; ++i) {
 653                 ir_node *irn;
 654                 int c;
 655
 656                 irn = get_compound_ent_value(ent, i);
 657                 c = (int) get_tarval_long(get_Const_tarval(irn));
 658
 659                 switch (c) {
 660                 case '"' : be_emit_cstring("\\\""); break;
 661                 case '\n': be_emit_cstring("\\n"); break;
 662                 case '\r': be_emit_cstring("\\r"); break;
 663                 case '\t': be_emit_cstring("\\t"); break;
 664                 case '\\': be_emit_cstring("\\\\"); break;
 665                 default  :
 666                         if (isprint(c))
 667                                 be_emit_char(c);
 668                         else
 669                                 be_emit_irprintf("\\%o", c);
 670                         break;
 671                 }
 672         }
 673         be_emit_cstring("\"\n");
 674         be_emit_write_line();
 675
 676         type            = get_entity_type(ent);
 677         type_size       = get_type_size_bytes(type);
 678         remaining_space = type_size - len;
 679         assert(remaining_space >= 0);
 680         if (remaining_space > 0) {
 681                 be_emit_irprintf("\t.space\t%d\n", remaining_space);
 682         }
 683 }
 684
 685 static void dump_string_initializer(const ir_initializer_t *initializer)
 686 {
 687         size_t i, len;
 688
 689         len = initializer->compound.n_initializers;
 690         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
 691                 be_emit_cstring("\t.ascii \"");
 692         } else {
 693                 be_emit_cstring("\t.string \"");
 694                 len -= 1;
 695         }
 696
 697         for (i = 0; i < len; ++i) {
 698                 const ir_initializer_t *sub_initializer
 699                         = get_initializer_compound_value(initializer, i);
 700
 701                 tarval *tv = get_initializer_tarval_value(sub_initializer);
 702                 int     c  = get_tarval_long(tv);
 703
 704                 switch (c) {
 705                 case '"' : be_emit_cstring("\\\""); break;
 706                 case '\n': be_emit_cstring("\\n"); break;
 707                 case '\r': be_emit_cstring("\\r"); break;
 708                 case '\t': be_emit_cstring("\\t"); break;
 709                 case '\\': be_emit_cstring("\\\\"); break;
 710                 default  :
 711                         if (isprint(c))
 712                                 be_emit_char(c);
 713                         else
 714                                 be_emit_irprintf("\\%o", c);
 715                         break;
 716                 }
 717         }
 718         be_emit_cstring("\"\n");
 719         be_emit_write_line();
 720 }
 721
 722 enum normal_or_bitfield_kind {
 723         NORMAL = 0,
 724         TARVAL,
 725         BITFIELD
 726 };
 727
 728 typedef struct {
 729         enum normal_or_bitfield_kind kind;
 730         union {
 731                 ir_node       *value;
 732                 tarval        *tarval;
 733                 unsigned char  bf_val;
 734         } v;
 735 } normal_or_bitfield;
 736
 737 static int is_type_variable_size(ir_type *type)
 738 {
 739         (void) type;
 740         /* TODO */
 741         return 0;
 742 }
 743
 744 static size_t get_initializer_size(const ir_initializer_t *initializer,
 745                                    ir_type *type)
 746 {
 747         switch (get_initializer_kind(initializer)) {
 748         case IR_INITIALIZER_TARVAL:
 749                 assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type));
 750                 return get_type_size_bytes(type);
 751         case IR_INITIALIZER_CONST:
 752         case IR_INITIALIZER_NULL:
 753                 return get_type_size_bytes(type);
 754         case IR_INITIALIZER_COMPOUND:
 755                 if (!is_type_variable_size(type)) {
 756                         return get_type_size_bytes(type);
 757                 } else {
 758                         unsigned n_entries
 759                                 = get_initializer_compound_n_entries(initializer);
 760                         unsigned i;
 761                         unsigned initializer_size = get_type_size_bytes(type);
 762                         for (i = 0; i < n_entries; ++i) {
 763                                 ir_entity *entity = get_compound_member(type, i);
 764                                 ir_type   *type   = get_entity_type(entity);
 765
 766                                 const ir_initializer_t *sub_initializer
 767                                         = get_initializer_compound_value(initializer, i);
 768
 769                                 unsigned offset = get_entity_offset(entity);
 770                                 unsigned size   = get_initializer_size(sub_initializer, type);
 771
 772                                 if (offset + size > initializer_size) {
 773                                         initializer_size = offset + size;
 774                                 }
 775                         }
 776                         return initializer_size;
 777                 }
 778         }
 779
 780         panic("found invalid initializer");
 781 }
 782
 783 #ifndef NDEBUG
 784 static normal_or_bitfield *glob_vals;
 785 static size_t              max_vals;
 786 #endif
 787
 788 static void dump_bitfield(normal_or_bitfield *vals, size_t offset_bits,
 789                           const ir_initializer_t *initializer, ir_type *type)
 790 {
 791         unsigned char  last_bits = 0;
 792         ir_mode       *mode      = get_type_mode(type);
 793         tarval        *tv        = NULL;
 794         unsigned char  curr_bits;
 795         int            value_len;
 796         int            j;
 797
 798         switch (get_initializer_kind(initializer)) {
 799         case IR_INITIALIZER_NULL:
 800                 return;
 801         case IR_INITIALIZER_TARVAL:
 802                 tv = get_initializer_tarval_value(initializer);
 803                 break;
 804         case IR_INITIALIZER_CONST: {
 805                 ir_node *node = get_initializer_const_value(initializer);
 806                 if (!is_Const(node)) {
 807                         panic("bitfield initializer not a Const node");
 808                 }
 809                 tv = get_Const_tarval(node);
 810                 break;
 811         }
 812         case IR_INITIALIZER_COMPOUND:
 813                 panic("bitfield initializer is compound");
 814         }
 815         if (tv == NULL) {
 816                 panic("Couldn't get numeric value for bitfield initializer");
 817         }
 818         tv = tarval_convert_to(tv, get_type_mode(type));
 819
 820         /* normalize offset */
 821         vals        += offset_bits >> 3;
 822         offset_bits &= 7;
 823         value_len    = get_mode_size_bits(mode);
 824
 825         /* combine bits with existing bits */
 826         for (j = 0; value_len + (int) offset_bits > 0; ++j) {
 827                 assert((size_t) (vals - glob_vals) + j < max_vals);
 828                 assert(vals[j].kind == BITFIELD ||
 829                                 (vals[j].kind == NORMAL && vals[j].v.value == NULL));
 830                 vals[j].kind = BITFIELD;
 831                 curr_bits    = get_tarval_sub_bits(tv, j);
 832                 vals[j].v.bf_val
 833                         |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
 834                 value_len -= 8;
 835                 last_bits = curr_bits;
 836         }
 837 }
 838
 839 static void dump_ir_initializer(normal_or_bitfield *vals,
 840                                 const ir_initializer_t *initializer,
 841                                 ir_type *type)
 842 {
 843         assert((size_t) (vals - glob_vals) < max_vals);
 844
 845         switch (get_initializer_kind(initializer)) {
 846         case IR_INITIALIZER_NULL:
 847                 return;
 848         case IR_INITIALIZER_TARVAL: {
 849                 size_t i;
 850
 851                 assert(vals->kind != BITFIELD);
 852                 vals->kind     = TARVAL;
 853                 vals->v.tarval = get_initializer_tarval_value(initializer);
 854                 assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval));
 855                 for (i = 1; i < get_type_size_bytes(type); ++i) {
 856                         vals[i].kind    = NORMAL;
 857                         vals[i].v.value = NULL;
 858                 }
 859                 return;
 860         }
 861         case IR_INITIALIZER_CONST: {
 862                 size_t i;
 863
 864                 assert(vals->kind != BITFIELD);
 865                 vals->kind    = NORMAL;
 866                 vals->v.value = get_initializer_const_value(initializer);
 867                 for (i = 1; i < get_type_size_bytes(type); ++i) {
 868                         vals[i].kind    = NORMAL;
 869                         vals[i].v.value = NULL;
 870                 }
 871                 return;
 872         }
 873         case IR_INITIALIZER_COMPOUND: {
 874                 size_t i = 0;
 875                 size_t n = get_initializer_compound_n_entries(initializer);
 876
 877                 if (is_Array_type(type)) {
 878                         ir_type *element_type = get_array_element_type(type);
 879                         size_t   skip         = get_type_size_bytes(element_type);
 880                         size_t   alignment    = get_type_alignment_bytes(element_type);
 881                         size_t   misalign     = skip % alignment;
 882                         if (misalign != 0) {
 883                                 skip += alignment - misalign;
 884                         }
 885
 886                         for (i = 0; i < n; ++i) {
 887                                 ir_initializer_t *sub_initializer
 888                                         = get_initializer_compound_value(initializer, i);
 889
 890                                 dump_ir_initializer(vals, sub_initializer, element_type);
 891
 892                                 vals += skip;
 893                         }
 894                 } else {
 895                         size_t n_members, i;
 896                         assert(is_compound_type(type));
 897                         n_members = get_compound_n_members(type);
 898                         for (i = 0; i < n_members; ++i) {
 899                                 ir_entity        *member    = get_compound_member(type, i);
 900                                 size_t            offset    = get_entity_offset(member);
 901                                 ir_type          *subtype   = get_entity_type(member);
 902                                 ir_mode          *mode      = get_type_mode(subtype);
 903                                 ir_initializer_t *sub_initializer;
 904
 905                                 assert(i < get_initializer_compound_n_entries(initializer));
 906                                 sub_initializer
 907                                         = get_initializer_compound_value(initializer, i);
 908
 909                                 if (mode != NULL) {
 910                                         size_t offset_bits
 911                                                 = get_entity_offset_bits_remainder(member);
 912                                         size_t value_len   = get_mode_size_bits(mode);
 913
 914                                         if (offset_bits != 0 ||
 915                                                 (value_len != 8 && value_len != 16 && value_len != 32
 916                                                  && value_len != 64)) {
 917                                                 dump_bitfield(&vals[offset], offset_bits,
 918                                                               sub_initializer, subtype);
 919                                                 continue;
 920                                         }
 921                                 }
 922
 923                                 dump_ir_initializer(&vals[offset], sub_initializer, subtype);
 924                         }
 925                 }
 926
 927                 return;
 928         }
 929         }
 930         panic("invalid ir_initializer kind found");
 931 }
 932
 933 static void dump_initializer(be_gas_decl_env_t *env, const ir_entity *entity)
 934 {
 935         const ir_initializer_t *initializer = entity->initializer;
 936         ir_type                *type;
 937         normal_or_bitfield     *vals;
 938         size_t                  size;
 939         size_t                  k;
 940
 941         if (initializer_is_string_const(initializer)) {
 942                 dump_string_initializer(initializer);
 943                 return;
 944         }
 945
 946         type = get_entity_type(entity);
 947         size = get_initializer_size(initializer, type);
 948
 949         if (size == 0)
 950                 return;
 951
 952         /*
 953          * In the worst case, every initializer allocates one byte.
 954          * Moreover, initializer might be big, do not allocate on stack.
 955          */
 956         vals = XMALLOCNZ(normal_or_bitfield, size);
 957
 958 #ifndef NDEBUG
 959         glob_vals = vals;
 960         max_vals  = size;
 961 #endif
 962
 963         dump_ir_initializer(vals, initializer, type);
 964
 965         /* now write values sorted */
 966         for (k = 0; k < size; ) {
 967                 int space     = 0;
 968                 int elem_size = 1;
 969                 if (vals[k].kind == NORMAL) {
 970                         if (vals[k].v.value != NULL) {
 971                                 dump_atomic_init(env, vals[k].v.value);
 972                                 elem_size = get_mode_size_bytes(get_irn_mode(vals[k].v.value));
 973                         } else {
 974                                 elem_size = 0;
 975                         }
 976                 } else if (vals[k].kind == TARVAL) {
 977                         tarval *tv   = vals[k].v.tarval;
 978                         size_t  size = get_mode_size_bytes(get_tarval_mode(tv));
 979
 980                         assert(tv != NULL);
 981
 982                         elem_size = size;
 983                         dump_size_type(size);
 984                         dump_arith_tarval(tv, size);
 985                         be_emit_char('\n');
 986                         be_emit_write_line();
 987                 } else {
 988                         assert(vals[k].kind == BITFIELD);
 989                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
 990                         be_emit_write_line();
 991                 }
 992
 993                 k += elem_size;
 994                 while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
 995                         ++space;
 996                         ++k;
 997                 }
 998
 999                 /* a gap */
1000                 if (space > 0) {
1001                         be_emit_irprintf("\t.space\t%d\n", space);
1002                         be_emit_write_line();
1003                 }
1004         }
1005         xfree(vals);
1006 }
1007
1008 static void dump_compound_graph_init(be_gas_decl_env_t *env,
1009                                      const ir_entity *ent)
1010 {
1011         normal_or_bitfield *vals;
1012         int i, j, n;
1013         unsigned k, last_ofs;
1014
1015         if (ent_is_string_const(ent)) {
1016                 dump_string_cst(ent);
1017                 return;
1018         }
1019
1020         n = get_compound_ent_n_values(ent);
1021
1022         /* Find the initializer size. Sorrily gcc support a nasty feature:
1023            The last field of a compound may be a flexible array. This allows
1024            initializers bigger than the type size. */
1025         last_ofs = get_type_size_bytes(get_entity_type(ent));
1026         for (i = 0; i < n; ++i) {
1027                 unsigned offset         = get_compound_ent_value_offset_bytes(ent, i);
1028                 unsigned bits_remainder = get_compound_ent_value_offset_bit_remainder(ent, i);
1029                 ir_node  *value         = get_compound_ent_value(ent, i);
1030                 unsigned value_len      = get_mode_size_bits(get_irn_mode(value));
1031
1032                 offset += (value_len + bits_remainder + 7) >> 3;
1033
1034                 if (offset > last_ofs) {
1035                         last_ofs = offset;
1036                 }
1037         }
1038
1039         /*
1040          * In the worst case, every initializer allocates one byte.
1041          * Moreover, initializer might be big, do not allocate on stack.
1042          */
1043         vals = XMALLOCNZ(normal_or_bitfield, last_ofs);
1044
1045         /* collect the values and store them at the offsets */
1046         for (i = 0; i < n; ++i) {
1047                 unsigned offset      = get_compound_ent_value_offset_bytes(ent, i);
1048                 int      offset_bits = get_compound_ent_value_offset_bit_remainder(ent, i);
1049                 ir_node  *value      = get_compound_ent_value(ent, i);
1050                 int      value_len   = get_mode_size_bits(get_irn_mode(value));
1051
1052                 assert(offset_bits >= 0);
1053
1054                 if (offset_bits != 0 ||
1055                                 (value_len != 8 && value_len != 16 && value_len != 32 && value_len != 64)) {
1056                         tarval *tv = get_atomic_init_tv(value);
1057                         unsigned char curr_bits, last_bits = 0;
1058                         if (tv == NULL) {
1059                                 panic("Couldn't get numeric value for bitfield initializer '%s'",
1060                                                 get_entity_ld_name(ent));
1061                         }
1062                         /* normalize offset */
1063                         offset += offset_bits >> 3;
1064                         offset_bits &= 7;
1065
1066                         for (j = 0; value_len + offset_bits > 0; ++j) {
1067                                 assert(offset + j < last_ofs);
1068                                 assert(vals[offset + j].kind == BITFIELD || vals[offset + j].v.value == NULL);
1069                                 vals[offset + j].kind = BITFIELD;
1070                                 curr_bits = get_tarval_sub_bits(tv, j);
1071                                 vals[offset + j].v.bf_val |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
1072                                 value_len -= 8;
1073                                 last_bits = curr_bits;
1074                         }
1075                 } else {
1076                         int i;
1077
1078                         assert(offset < last_ofs);
1079                         assert(vals[offset].kind == NORMAL);
1080                         for (i = 1; i < value_len / 8; ++i) {
1081                                 assert(vals[offset + i].v.value == NULL);
1082                         }
1083                         vals[offset].v.value = value;
1084                 }
1085         }
1086
1087         /* now write them sorted */
1088         for (k = 0; k < last_ofs; ) {
1089                 int space = 0, skip = 0;
1090                 if (vals[k].kind == NORMAL) {
1091                         if (vals[k].v.value != NULL) {
1092                                 dump_atomic_init(env, vals[k].v.value);
1093                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
1094                         } else {
1095                                 space = 1;
1096                         }
1097                 } else {
1098                         assert(vals[k].kind == BITFIELD);
1099                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1100                 }
1101
1102                 ++k;
1103                 while (k < last_ofs && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1104                         ++space;
1105                         ++k;
1106                 }
1107                 space -= skip;
1108                 assert(space >= 0);
1109
1110                 /* a gap */
1111                 if (space > 0) {
1112                         be_emit_irprintf("\t.space\t%d\n", space);
1113                         be_emit_write_line();
1114                 }
1115         }
1116         xfree(vals);
1117 }
1118
1119 static void emit_align(unsigned p2alignment)
1120 {
1121         be_emit_irprintf("\t.p2align\t%u\n", log2_floor(p2alignment));
1122         be_emit_write_line();
1123 }
1124
1125 static unsigned get_effective_entity_alignment(const ir_entity *entity)
1126 {
1127         unsigned alignment = get_entity_alignment(entity);
1128         if (alignment == 0) {
1129                 ir_type *type = get_entity_type(entity);
1130                 alignment     = get_type_alignment_bytes(type);
1131         }
1132         return alignment;
1133 }
1134
1135 static be_gas_section_t determine_section(be_gas_decl_env_t *env,
1136                                           const ir_entity *entity)
1137 {
1138         ir_type *owner = get_entity_owner(entity);
1139
1140         if (owner == get_segment_type(IR_SEGMENT_GLOBAL)) {
1141                 ir_linkage linkage = get_entity_linkage(entity);
1142                 if (linkage & IR_LINKAGE_CONSTANT) {
1143                         /* mach-o is the only one with a cstring section */
1144                         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O
1145                                         && ent_is_string_const(entity))
1146                                 return GAS_SECTION_CSTRING;
1147
1148                         return GAS_SECTION_RODATA;
1149                 }
1150                 if (!entity_has_definition(entity))
1151                         return GAS_SECTION_BSS;
1152
1153                 return GAS_SECTION_DATA;
1154
1155         } else if (owner == env->main_env->pic_symbols_type) {
1156                 return GAS_SECTION_PIC_SYMBOLS;
1157         } else if (owner == env->main_env->pic_trampolines_type) {
1158                 return GAS_SECTION_PIC_TRAMPOLINES;
1159         } else if (owner == get_segment_type(IR_SEGMENT_CONSTRUCTORS)) {
1160                 return GAS_SECTION_CONSTRUCTORS;
1161         } else if (owner == get_segment_type(IR_SEGMENT_DESTRUCTORS)) {
1162                 return GAS_SECTION_DESTRUCTORS;
1163         } else if (owner == get_segment_type(IR_SEGMENT_THREAD_LOCAL)) {
1164                 return GAS_SECTION_TLS;
1165         }
1166
1167         panic("Couldn't determine section for %+F?!?", entity);
1168 }
1169
1170 static void emit_common(const ir_entity *ent)
1171 {
1172         const char *name      = get_entity_ld_name(ent);
1173         unsigned    size      = get_type_size_bytes(get_entity_type(ent));
1174         unsigned    alignment = get_effective_entity_alignment(ent);
1175
1176         switch (be_gas_object_file_format) {
1177         case OBJECT_FILE_FORMAT_MACH_O:
1178                 be_emit_irprintf("\t.comm %s,%u,%u\n", name, size,
1179                                  log2_floor(alignment));
1180                 be_emit_write_line();
1181                 return;
1182         case OBJECT_FILE_FORMAT_ELF:
1183                 be_emit_irprintf("\t.comm %s,%u,%u\n", name, size, alignment);
1184                 be_emit_write_line();
1185                 return;
1186         case OBJECT_FILE_FORMAT_COFF:
1187                 be_emit_irprintf("\t.comm %s,%u # %u\n", name, size, alignment);
1188                 be_emit_write_line();
1189                 return;
1190         }
1191         panic("invalid object file format");
1192 }
1193
1194 /**
1195  * Dump a global entity.
1196  *
1197  * @param env  the gas output environment
1198  * @param ent  the entity to be dumped
1199  */
1200 static void dump_global(be_gas_decl_env_t *env, const ir_entity *ent)
1201 {
1202         ir_type          *type           = get_entity_type(ent);
1203         ident            *ld_ident       = get_entity_ld_ident(ent);
1204         unsigned          alignment      = get_effective_entity_alignment(ent);
1205         be_gas_section_t  section        = determine_section(env, ent);
1206         ir_linkage        linkage        = get_entity_linkage(ent);
1207
1208         /* we already emitted all methods. Except for the trampolines which
1209          * the assembler/linker generates */
1210         if (is_Method_type(type) && section != GAS_SECTION_PIC_TRAMPOLINES) {
1211                 return;
1212         }
1213         /* block labels are already emittet in the code */
1214         if (type == firm_code_type)
1215                 return;
1216
1217         be_dbg_variable(ent);
1218
1219         /* nothing to do for externally defined values */
1220         if (linkage & IR_LINKAGE_EXTERN)
1221                 return;
1222
1223         if (!is_po2(alignment))
1224                 panic("alignment not a power of 2");
1225
1226         if (section == GAS_SECTION_BSS &&
1227                         (get_entity_linkage(ent) & IR_LINKAGE_MERGE)) {
1228                 emit_common(ent);
1229                 return;
1230         }
1231
1232         be_gas_emit_switch_section(section);
1233
1234         /* alignment */
1235         if (alignment > 1) {
1236                 emit_align(alignment);
1237         }
1238         emit_entity_visibility(ent);
1239         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_ELF
1240                         && be_gas_emit_types) {
1241                 be_emit_cstring("\t.type\t");
1242                 be_emit_ident(ld_ident);
1243                 be_emit_cstring(", ");
1244                 be_emit_char(be_gas_elf_type_char);
1245                 be_emit_cstring("object\n\t.size\t");
1246                 be_emit_ident(ld_ident);
1247                 be_emit_irprintf(", %u\n", get_type_size_bytes(type));
1248         }
1249         be_emit_ident(ld_ident);
1250         be_emit_cstring(":\n");
1251         be_emit_write_line();
1252
1253         if (ent->initializer != NULL) {
1254                 dump_initializer(env, ent);
1255         } else if(entity_has_compound_ent_values(ent)) {
1256                 dump_compound_graph_init(env, ent);
1257         } else {
1258                 /* uninitialized */
1259                 be_emit_irprintf("\t.space %u\n", get_type_size_bytes(type));
1260                 be_emit_write_line();
1261         }
1262 }
1263
1264 /**
1265  * Dumps declarations of global variables and the initialization code.
1266  *
1267  * @param gt                a global like type, either the global or the TLS one
1268  * @param env               an environment
1269  * @param only_emit_marked  if non-zero, external allocated entities that do not have
1270  *                          its visited flag set are ignored
1271  */
1272 static void be_gas_dump_globals(ir_type *gt, be_gas_decl_env_t *env,
1273                                 int only_emit_marked)
1274 {
1275         int i, n = get_compound_n_members(gt);
1276         waitq *worklist = new_waitq();
1277
1278         if (only_emit_marked) {
1279                 for (i = 0; i < n; i++) {
1280                         ir_entity *ent = get_compound_member(gt, i);
1281                         if (is_entity_backend_marked(ent) || entity_has_definition(ent)) {
1282                                 waitq_put(worklist, ent);
1283                                 set_entity_backend_marked(ent, 1);
1284                         }
1285                 }
1286         } else {
1287                 for (i = 0; i < n; i++) {
1288                         ir_entity *ent = get_compound_member(gt, i);
1289                         set_entity_backend_marked(ent, 1);
1290                         waitq_put(worklist, ent);
1291                 }
1292         }
1293
1294         env->worklist = worklist;
1295
1296         while (!waitq_empty(worklist)) {
1297                 ir_entity *ent = waitq_get(worklist);
1298
1299                 dump_global(env, ent);
1300         }
1301
1302         del_waitq(worklist);
1303         env->worklist = NULL;
1304 }
1305
1306 /************************************************************************/
1307
1308 /* Generate all entities. */
1309 void be_gas_emit_decls(const be_main_env_t *main_env,
1310                        int only_emit_marked_entities)
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, only_emit_marked_entities);
1320         be_gas_dump_globals(get_tls_type(), &env, only_emit_marked_entities);
1321         be_gas_dump_globals(get_segment_type(IR_SEGMENT_CONSTRUCTORS), &env,
1322                             only_emit_marked_entities);
1323         be_gas_dump_globals(get_segment_type(IR_SEGMENT_DESTRUCTORS), &env,
1324                             only_emit_marked_entities);
1325         be_gas_dump_globals(main_env->pic_symbols_type, &env,
1326                             only_emit_marked_entities);
1327         be_gas_dump_globals(main_env->pic_trampolines_type, &env,
1328                                                 only_emit_marked_entities);
1329
1330         /**
1331          * ".subsections_via_symbols marks object files which are OK to divide
1332          * their section contents into individual blocks".
1333          * From my understanding this means no label points in the middle of an
1334          * object which we want to address as a whole. Firm code should be fine
1335          * with this.
1336          */
1337         if (be_gas_object_file_format == OBJECT_FILE_FORMAT_MACH_O) {
1338                 be_emit_cstring("\t.subsections_via_symbols\n");
1339                 be_emit_write_line();
1340         }
1341 }