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 #ifdef HAVE_CONFIG_H
  28 #include "config.h"
  29 #endif
  30
  31 #include "begnuas.h"
  32
  33 #include <stdlib.h>
  34 #include <string.h>
  35 #include <ctype.h>
  36 #include <assert.h>
  37
  38 #include "obst.h"
  39 #include "tv.h"
  40 #include "irnode.h"
  41 #include "irprog.h"
  42 #include "pdeq.h"
  43 #include "entity_t.h"
  44 #include "error.h"
  45
  46 #include "be_t.h"
  47 #include "beemitter.h"
  48 #include "be_dbgout.h"
  49
  50 /** by default, we generate assembler code for the Linux gas */
  51 be_gas_flavour_t be_gas_flavour = GAS_FLAVOUR_ELF;
  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         static const char *text[GAS_FLAVOUR_LAST+1][GAS_SECTION_LAST+1] = {
  65                 { /* GAS_FLAVOUR_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                 { /* GAS_FLAVOUR_MINGW */
  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,\"aw\",@progbits",
  84                         ".section\t.dtors,\"aw\",@progbits",
  85                         NULL,
  86                         NULL,
  87                         NULL
  88                 },
  89                 { /* GAS_FLAVOUR_YASM */
  90                         ".section\t.text",
  91                         ".section\t.data",
  92                         ".section\t.rodata",
  93                         ".section\t.bss",
  94                         ".section\t.tbss,\"awT\",@nobits",
  95                         ".section\t.ctors,\"aw\",@progbits",
  96                         ".section\t.dtors,\"aw\",@progbits",
  97                         NULL,
  98                         NULL,
  99                         NULL
 100                 },
 101                 { /* GAS_FLAVOUR_MACH_O */
 102                         ".text",
 103                         ".data",
 104                         ".const",
 105                         ".data",
 106                         NULL,             /* TLS is not supported on Mach-O */
 107                         ".mod_init_func",
 108                         NULL,             /* TODO: how is this called? */
 109                         ".cstring",
 110                         ".section\t__IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_instructions,5",
 111                         ".section\t__IMPORT,__pointers,non_lazy_symbol_pointers"
 112                 }
 113         };
 114
 115         assert((int) be_gas_flavour >= 0 && be_gas_flavour <= GAS_FLAVOUR_LAST);
 116         assert((int) section >= 0 && section <= GAS_SECTION_LAST);
 117         return text[be_gas_flavour][section];
 118 }
 119
 120 void be_gas_emit_switch_section(be_gas_section_t section) {
 121         if(current_section == section)
 122                 return;
 123
 124         be_emit_char('\t');
 125         be_emit_string(get_section_name(section));
 126         be_emit_char('\n');
 127         be_emit_write_line();
 128         current_section = section;
 129 }
 130
 131 void be_gas_emit_function_prolog(ir_entity *entity, unsigned alignment)
 132 {
 133         const char *name = get_entity_ld_name(entity);
 134         const char *fill_byte = "";
 135         unsigned maximum_skip;
 136
 137         be_gas_emit_switch_section(GAS_SECTION_TEXT);
 138
 139         /* write the begin line (used by scripts processing the assembler... */
 140         be_emit_write_line();
 141         be_emit_cstring("# -- Begin  ");
 142         be_emit_string(name);
 143         be_emit_char('\n');
 144         be_emit_write_line();
 145
 146         /* gcc fills space between function with 0x90, no idea if this is needed */
 147         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
 148                 fill_byte = "0x90";
 149         }
 150
 151         if (alignment > 0) {
 152                 maximum_skip = (1 << alignment) - 1;
 153                 be_emit_cstring("\t.p2align ");
 154                 be_emit_irprintf("%u,%s,%u\n", alignment, fill_byte, maximum_skip);
 155                 be_emit_write_line();
 156         }
 157         if (get_entity_visibility(entity) == visibility_external_visible) {
 158                 be_emit_cstring(".globl ");
 159                 be_emit_string(name);
 160                 be_emit_char('\n');
 161                 be_emit_write_line();
 162         }
 163
 164         switch (be_gas_flavour) {
 165         case GAS_FLAVOUR_ELF:
 166                 be_emit_cstring("\t.type\t");
 167                 be_emit_string(name);
 168                 be_emit_cstring(", @function\n");
 169                 be_emit_write_line();
 170                 break;
 171         case GAS_FLAVOUR_MINGW:
 172                 be_emit_cstring("\t.def\t");
 173                 be_emit_string(name);
 174                 be_emit_cstring(";\t.scl\t2;\t.type\t32;\t.endef\n");
 175                 be_emit_write_line();
 176                 break;
 177         case GAS_FLAVOUR_MACH_O:
 178         case GAS_FLAVOUR_YASM:
 179                 break;
 180         }
 181         be_emit_string(name);
 182         be_emit_cstring(":\n");
 183         be_emit_write_line();
 184 }
 185
 186 void be_gas_emit_function_epilog(ir_entity *entity)
 187 {
 188         const char *name = get_entity_ld_name(entity);
 189
 190         if (be_gas_flavour == GAS_FLAVOUR_ELF) {
 191                 be_emit_cstring("\t.size\t");
 192                 be_emit_string(name);
 193                 be_emit_cstring(", .-");
 194                 be_emit_string(name);
 195                 be_emit_char('\n');
 196                 be_emit_write_line();
 197         }
 198
 199         be_emit_cstring("# -- End  ");
 200         be_emit_string(name);
 201         be_emit_char('\n');
 202         be_emit_write_line();
 203 }
 204
 205 /**
 206  * An environment containing all needed dumper data.
 207  * Currently we create the file completely in memory first, then
 208  * write it to the disk. This is an artifact from the old C-generating backend
 209  * and even there NOT needed. So we might change it in the future.
 210  */
 211 typedef struct _be_gas_decl_env {
 212         const be_main_env_t *main_env; /**< The main backend environment, used for it's debug handle. */
 213         be_gas_section_t     section;
 214         waitq               *worklist;           /**< A worklist we use to place not yet handled entities on. */
 215 } be_gas_decl_env_t;
 216
 217 /************************************************************************/
 218
 219 /**
 220  * Output a tarval.
 221  *
 222  * @param tv     the tarval
 223  * @param bytes  the width of the tarvals value in bytes
 224  */
 225 static void dump_arith_tarval(tarval *tv, int bytes)
 226 {
 227         switch (bytes) {
 228         case 1:
 229                 be_emit_irprintf("0x%02x", get_tarval_sub_bits(tv, 0));
 230                 return;
 231
 232         case 2:
 233                 be_emit_irprintf("0x%02x%02x", get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 234                 return;
 235
 236         case 4:
 237                 be_emit_irprintf("0x%02x%02x%02x%02x",
 238                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 239                 return;
 240
 241         case 8:
 242                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x",
 243                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6), get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
 244                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
 245                 return;
 246
 247         case 12:
 248                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x"
 249                                    "%02x%02x%02x%02x", get_tarval_sub_bits(tv, 11),
 250                                 get_tarval_sub_bits(tv, 10), get_tarval_sub_bits(tv, 9),
 251                                 get_tarval_sub_bits(tv, 8), get_tarval_sub_bits(tv, 7),
 252                                 get_tarval_sub_bits(tv, 6), get_tarval_sub_bits(tv, 5),
 253                                 get_tarval_sub_bits(tv, 4), get_tarval_sub_bits(tv, 3),
 254                                 get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1),
 255                                 get_tarval_sub_bits(tv, 0));
 256                 return;
 257
 258         case 16:
 259                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x"
 260                                                "%02x%02x%02x%02x%02x%02x%02x%02x",
 261                         get_tarval_sub_bits(tv, 15), get_tarval_sub_bits(tv, 16),
 262                         get_tarval_sub_bits(tv, 13), get_tarval_sub_bits(tv, 12),
 263                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
 264                         get_tarval_sub_bits(tv, 9), get_tarval_sub_bits(tv, 8),
 265                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6),
 266                         get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
 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                 return;
 270         }
 271
 272         panic("Can't dump a tarval with %d bytes\n", bytes);
 273 }
 274
 275 /**
 276  * Return the label prefix for labeled blocks.
 277  */
 278 const char *be_gas_block_label_prefix(void) {
 279         return ".LG";
 280 }
 281
 282 /**
 283  * Return the label prefix for labeled instructions.
 284  */
 285 const char *be_gas_insn_label_prefix(void) {
 286         return ".LE";
 287 }
 288
 289 /**
 290  * Dump a label.
 291  */
 292 static void dump_label(ir_label_t label) {
 293         be_emit_irprintf("%s%lu", be_gas_block_label_prefix(), label);
 294 }
 295
 296 /**
 297  * Return the tarval of an atomic initializer.
 298  *
 299  * @param init  a node representing the initializer (on the const code irg)
 300  *
 301  * @return the tarval
 302  */
 303 static tarval *get_atomic_init_tv(ir_node *init)
 304 {
 305         for (;;) {
 306                 ir_mode *mode = get_irn_mode(init);
 307
 308                 switch (get_irn_opcode(init)) {
 309
 310                 case iro_Cast:
 311                         init = get_Cast_op(init);
 312                         continue;
 313
 314                 case iro_Conv:
 315                         init = get_Conv_op(init);
 316                         continue;
 317
 318                 case iro_Const:
 319                         return get_Const_tarval(init);
 320
 321                 case iro_SymConst:
 322                         switch (get_SymConst_kind(init)) {
 323                         case symconst_type_size:
 324                                 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(init)), mode);
 325
 326                         case symconst_type_align:
 327                                 return new_tarval_from_long(get_type_alignment_bytes(get_SymConst_type(init)), mode);
 328
 329                         case symconst_ofs_ent:
 330                                 return new_tarval_from_long(get_entity_offset(get_SymConst_entity(init)), mode);
 331
 332                         case symconst_enum_const:
 333                                 return get_enumeration_value(get_SymConst_enum(init));
 334
 335                         case symconst_label:
 336                                 return NULL;
 337
 338                         default:
 339                                 return NULL;
 340                         }
 341
 342                 default:
 343                         return NULL;
 344                 }
 345         }
 346 }
 347
 348 /**
 349  * Dump an atomic value.
 350  *
 351  * @param env   the gas output environment
 352  * @param init  a node representing the atomic value (on the const code irg)
 353  */
 354 static void do_dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 355 {
 356         ir_mode *mode = get_irn_mode(init);
 357         int bytes     = get_mode_size_bytes(mode);
 358         tarval *tv;
 359         ir_label_t label;
 360         ir_entity *ent;
 361
 362         init = skip_Id(init);
 363
 364         switch (get_irn_opcode(init)) {
 365         case iro_Cast:
 366                 do_dump_atomic_init(env, get_Cast_op(init));
 367                 return;
 368
 369         case iro_Conv:
 370                 do_dump_atomic_init(env, get_Conv_op(init));
 371                 return;
 372
 373         case iro_Const:
 374                 tv = get_Const_tarval(init);
 375
 376                 /* it's a arithmetic value */
 377                 dump_arith_tarval(tv, bytes);
 378                 return;
 379
 380         case iro_SymConst:
 381                 switch (get_SymConst_kind(init)) {
 382                 case symconst_addr_name:
 383                         be_emit_ident(get_SymConst_name(init));
 384                         break;
 385
 386                 case symconst_addr_ent:
 387                         ent = get_SymConst_entity(init);
 388                         if(!is_entity_backend_marked(ent)) {
 389                                 waitq_put(env->worklist, ent);
 390                                 set_entity_backend_marked(ent, 1);
 391                         }
 392                         be_emit_ident(get_entity_ld_ident(ent));
 393                         break;
 394
 395                 case symconst_ofs_ent:
 396                         ent = get_SymConst_entity(init);
 397 #if 0       /* not needed, is it? */
 398                         if(!is_entity_backend_marked(ent)) {
 399                                 waitq_put(env->worklist, ent);
 400                                 set_entity_backend_marked(ent, 1);
 401                         }
 402 #endif
 403                         be_emit_irprintf("%d", get_entity_offset(ent));
 404                         break;
 405
 406                 case symconst_type_size:
 407                         be_emit_irprintf("%u", get_type_size_bytes(get_SymConst_type(init)));
 408                         break;
 409
 410                 case symconst_type_align:
 411                         be_emit_irprintf("%u", get_type_alignment_bytes(get_SymConst_type(init)));
 412                         break;
 413
 414                 case symconst_enum_const:
 415                         tv = get_enumeration_value(get_SymConst_enum(init));
 416                         dump_arith_tarval(tv, bytes);
 417                         break;
 418
 419                 case symconst_label:
 420                         label = get_SymConst_label(init);
 421                         dump_label(label);
 422                         break;
 423
 424                 default:
 425                         assert(!"dump_atomic_init(): don't know how to init from this SymConst");
 426                 }
 427                 return;
 428
 429                 case iro_Add:
 430                         if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 431                                 panic("Constant must be int or pointer for '+' to work");
 432                         }
 433                         do_dump_atomic_init(env, get_Add_left(init));
 434                         be_emit_cstring(" + ");
 435                         do_dump_atomic_init(env, get_Add_right(init));
 436                         return;
 437
 438                 case iro_Sub:
 439                         if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 440                                 panic("Constant must be int or pointer for '-' to work");
 441                         }
 442                         do_dump_atomic_init(env, get_Sub_left(init));
 443                         be_emit_cstring(" - ");
 444                         do_dump_atomic_init(env, get_Sub_right(init));
 445                         return;
 446
 447                 case iro_Mul:
 448                         if (!mode_is_int(mode) && !mode_is_reference(mode)) {
 449                                 panic("Constant must be int or pointer for '*' to work");
 450                         }
 451                         do_dump_atomic_init(env, get_Mul_left(init));
 452                         be_emit_cstring(" * ");
 453                         do_dump_atomic_init(env, get_Mul_right(init));
 454                         return;
 455
 456                 default:
 457                         assert(0 && "dump_atomic_init(): unknown IR-node");
 458         }
 459 }
 460
 461 /**
 462  * Dumps the type for given size (.byte, .long, ...)
 463  *
 464  * @param size  the size in bytes
 465  */
 466 static void dump_size_type(size_t size) {
 467         switch (size) {
 468         case 1:
 469                 be_emit_cstring("\t.byte\t");
 470                 break;
 471
 472         case 2:
 473                 be_emit_cstring("\t.word\t");
 474                 break;
 475
 476         case 4:
 477                 be_emit_cstring("\t.long\t");
 478                 break;
 479
 480         case 8:
 481                 be_emit_cstring("\t.quad\t");
 482                 break;
 483
 484         case 10:
 485         case 12:
 486                 /* handled in arith */
 487                 break;
 488
 489         case 16:
 490                 be_emit_cstring("\t.octa\t");
 491                 break;
 492
 493         default:
 494                 panic("Try to dump a type with %u bytes\n", (unsigned) size);
 495         }
 496 }
 497
 498 /**
 499  * Emit an atomic value.
 500  *
 501  * @param env   the gas output environment
 502  * @param init  a node representing the atomic value (on the const code irg)
 503  */
 504 static void dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
 505 {
 506         ir_mode *mode = get_irn_mode(init);
 507         int bytes     = get_mode_size_bytes(mode);
 508
 509         dump_size_type(bytes);
 510         do_dump_atomic_init(env, init);
 511         be_emit_char('\n');
 512         be_emit_write_line();
 513 }
 514
 515 /************************************************************************/
 516 /* Routines to dump global variables                                    */
 517 /************************************************************************/
 518
 519 static int initializer_is_string_const(const ir_initializer_t *initializer)
 520 {
 521         size_t i, len;
 522         int found_printable = 0;
 523
 524         if(initializer->kind != IR_INITIALIZER_COMPOUND)
 525                 return 0;
 526
 527         len = initializer->compound.n_initializers;
 528         if (len < 1)
 529                 return 0;
 530         for(i = 0; i < len; ++i) {
 531                 int               c;
 532                 tarval           *tv;
 533                 ir_mode          *mode;
 534                 ir_initializer_t *sub_initializer
 535                         = initializer->compound.initializers[i];
 536
 537                 if(sub_initializer->kind != IR_INITIALIZER_TARVAL)
 538                         return 0;
 539
 540                 tv   = sub_initializer->tarval.value;
 541                 mode = get_tarval_mode(tv);
 542
 543                 if (!mode_is_int(mode)
 544                                 || get_mode_size_bits(mode) != get_mode_size_bits(mode_Bs))
 545                         return 0;
 546
 547                 c = get_tarval_long(tv);
 548                 if (isgraph(c) || isspace(c))
 549                         found_printable = 1;
 550                 else if(c != 0)
 551                         return 0;
 552
 553                 if (i == len - 1 && c != '\0')
 554                         return 0;
 555         }
 556
 557         return found_printable;
 558 }
 559
 560 /**
 561  * Determine if an entity is a string constant
 562  * @param ent The entity
 563  * @return 1 if it is a string constant, 0 otherwise
 564  */
 565 static int ent_is_string_const(ir_entity *ent)
 566 {
 567         ir_type *type, *element_type;
 568         ir_mode *mode;
 569         int i, c, n;
 570         int found_printable = 0;
 571
 572         type = get_entity_type(ent);
 573
 574         /* if it's an array */
 575         if (!is_Array_type(type))
 576                 return 0;
 577
 578         element_type = get_array_element_type(type);
 579
 580         /* and the array's element type is primitive */
 581         if (!is_Primitive_type(element_type))
 582                 return 0;
 583
 584         /* and the mode of the element type is an int of
 585          * the same size as the byte mode */
 586         mode = get_type_mode(element_type);
 587         if (!mode_is_int(mode)
 588                 || get_mode_size_bits(mode) != get_mode_size_bits(mode_Bs))
 589                 return 0;
 590
 591         if(ent->has_initializer) {
 592                 /* TODO */
 593                 return 0;
 594         } else {
 595                 /* if it contains only printable chars and a 0 at the end */
 596                 n = get_compound_ent_n_values(ent);
 597                 for (i = 0; i < n; ++i) {
 598                         ir_node *irn = get_compound_ent_value(ent, i);
 599                         if (! is_Const(irn))
 600                                 return 0;
 601
 602                         c = (int) get_tarval_long(get_Const_tarval(irn));
 603
 604                         if (isgraph(c) || isspace(c))
 605                                 found_printable = 1;
 606                         else if(c != 0)
 607                                 return 0;
 608
 609                         if (i == n - 1 && c != '\0')
 610                                 return 0;
 611                 }
 612         }
 613
 614         /* then we can emit it as a string constant */
 615         return found_printable;
 616 }
 617
 618 /**
 619  * Dump a string constant.
 620  * No checks are made!!
 621  *
 622  * @param ent  The entity to dump.
 623  */
 624 static void dump_string_cst(ir_entity *ent)
 625 {
 626         int      i, len;
 627         ir_type *type;
 628         int      type_size;
 629         int      remaining_space;
 630
 631         len = get_compound_ent_n_values(ent);
 632         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
 633                 be_emit_cstring("\t.ascii \"");
 634         } else {
 635                 be_emit_cstring("\t.string \"");
 636                 len -= 1;
 637         }
 638
 639         for (i = 0; i < len; ++i) {
 640                 ir_node *irn;
 641                 int c;
 642
 643                 irn = get_compound_ent_value(ent, i);
 644                 c = (int) get_tarval_long(get_Const_tarval(irn));
 645
 646                 switch (c) {
 647                 case '"' : be_emit_cstring("\\\""); break;
 648                 case '\n': be_emit_cstring("\\n"); break;
 649                 case '\r': be_emit_cstring("\\r"); break;
 650                 case '\t': be_emit_cstring("\\t"); break;
 651                 case '\\': be_emit_cstring("\\\\"); break;
 652                 default  :
 653                         if (isprint(c))
 654                                 be_emit_char(c);
 655                         else
 656                                 be_emit_irprintf("\\%o", c);
 657                         break;
 658                 }
 659         }
 660         be_emit_cstring("\"\n");
 661         be_emit_write_line();
 662
 663         type            = get_entity_type(ent);
 664         type_size       = get_type_size_bytes(type);
 665         remaining_space = type_size - len;
 666         assert(remaining_space >= 0);
 667         if(remaining_space > 0) {
 668                 be_emit_irprintf("\t.skip\t%d\n", remaining_space);
 669         }
 670 }
 671
 672 static void dump_string_initializer(const ir_initializer_t *initializer)
 673 {
 674         size_t i, len;
 675
 676         len = initializer->compound.n_initializers;
 677         if(be_gas_flavour == GAS_FLAVOUR_MACH_O) {
 678                 be_emit_cstring("\t.ascii \"");
 679         } else {
 680                 be_emit_cstring("\t.string \"");
 681                 len -= 1;
 682         }
 683
 684         for(i = 0; i < len; ++i) {
 685                 const ir_initializer_t *sub_initializer
 686                         = get_initializer_compound_value(initializer, i);
 687
 688                 tarval *tv = get_initializer_tarval_value(sub_initializer);
 689                 int     c  = get_tarval_long(tv);
 690
 691                 switch (c) {
 692                 case '"' : be_emit_cstring("\\\""); break;
 693                 case '\n': be_emit_cstring("\\n"); break;
 694                 case '\r': be_emit_cstring("\\r"); break;
 695                 case '\t': be_emit_cstring("\\t"); break;
 696                 case '\\': be_emit_cstring("\\\\"); break;
 697                 default  :
 698                         if (isprint(c))
 699                                 be_emit_char(c);
 700                         else
 701                                 be_emit_irprintf("\\%o", c);
 702                         break;
 703                 }
 704         }
 705         be_emit_cstring("\"\n");
 706         be_emit_write_line();
 707 }
 708
 709 enum normal_or_bitfield_kind {
 710         NORMAL = 0,
 711         TARVAL,
 712         BITFIELD
 713 };
 714
 715 typedef struct {
 716         enum normal_or_bitfield_kind kind;
 717         union {
 718                 ir_node       *value;
 719                 tarval        *tarval;
 720                 unsigned char  bf_val;
 721         } v;
 722 } normal_or_bitfield;
 723
 724 static int is_type_variable_size(ir_type *type)
 725 {
 726         (void) type;
 727         /* TODO */
 728         return 0;
 729 }
 730
 731 static size_t get_initializer_size(const ir_initializer_t *initializer,
 732                                    ir_type *type)
 733 {
 734         switch(get_initializer_kind(initializer)) {
 735         case IR_INITIALIZER_TARVAL: {
 736                 assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type));
 737                 return get_type_size_bytes(type);
 738         }
 739         case IR_INITIALIZER_CONST:
 740         case IR_INITIALIZER_NULL:
 741                 return get_type_size_bytes(type);
 742         case IR_INITIALIZER_COMPOUND: {
 743                 if(!is_type_variable_size(type)) {
 744                         return get_type_size_bytes(type);
 745                 } else {
 746                         unsigned n_entries
 747                                 = get_initializer_compound_n_entries(initializer);
 748                         unsigned i;
 749                         unsigned initializer_size = get_type_size_bytes(type);
 750                         for(i = 0; i < n_entries; ++i) {
 751                                 ir_entity *entity = get_compound_member(type, i);
 752                                 ir_type   *type   = get_entity_type(entity);
 753
 754                                 const ir_initializer_t *sub_initializer
 755                                         = get_initializer_compound_value(initializer, i);
 756
 757                                 unsigned offset = get_entity_offset(entity);
 758                                 unsigned size   = get_initializer_size(sub_initializer, type);
 759
 760                                 if(offset + size > initializer_size) {
 761                                         initializer_size = offset + size;
 762                                 }
 763                         }
 764                         return initializer_size;
 765                 }
 766         }
 767         }
 768
 769         panic("found invalid initializer");
 770 }
 771
 772 #ifndef NDEBUG
 773 static normal_or_bitfield *glob_vals;
 774 static size_t              max_vals;
 775 #endif
 776
 777 static void dump_bitfield(normal_or_bitfield *vals, size_t offset_bits,
 778                           const ir_initializer_t *initializer, ir_type *type)
 779 {
 780         unsigned char  last_bits = 0;
 781         ir_mode       *mode      = get_type_mode(type);
 782         tarval        *tv        = NULL;
 783         unsigned char  curr_bits;
 784         int            value_len;
 785         int            j;
 786
 787         switch(get_initializer_kind(initializer)) {
 788         case IR_INITIALIZER_NULL:
 789                 return;
 790         case IR_INITIALIZER_TARVAL:
 791                 tv = get_initializer_tarval_value(initializer);
 792                 break;
 793         case IR_INITIALIZER_CONST: {
 794                 ir_node *node = get_initializer_const_value(initializer);
 795                 if(!is_Const(node)) {
 796                         panic("bitfield initializer not a Const node");
 797                 }
 798                 tv = get_Const_tarval(node);
 799                 break;
 800         }
 801         case IR_INITIALIZER_COMPOUND:
 802                 panic("bitfield initializer is compound");
 803         }
 804         if (tv == NULL) {
 805                 panic("Couldn't get numeric value for bitfield initializer\n");
 806         }
 807
 808         /* normalize offset */
 809         vals        += offset_bits >> 3;
 810         offset_bits &= 7;
 811         value_len    = get_mode_size_bits(mode);
 812
 813         /* combine bits with existing bits */
 814         for (j = 0; value_len + (int) offset_bits > 0; ++j) {
 815                 assert((size_t) (vals - glob_vals) + j < max_vals);
 816                 assert(vals[j].kind == BITFIELD ||
 817                                 (vals[j].kind == NORMAL && vals[j].v.value == NULL));
 818                 vals[j].kind = BITFIELD;
 819                 curr_bits    = get_tarval_sub_bits(tv, j);
 820                 vals[j].v.bf_val
 821                         |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
 822                 value_len -= 8;
 823                 last_bits = curr_bits;
 824         }
 825 }
 826
 827 static void dump_ir_initializer(normal_or_bitfield *vals,
 828                                 const ir_initializer_t *initializer,
 829                                 ir_type *type)
 830 {
 831         assert((size_t) (vals - glob_vals) < max_vals);
 832
 833         switch(get_initializer_kind(initializer)) {
 834         case IR_INITIALIZER_NULL:
 835                 return;
 836         case IR_INITIALIZER_TARVAL: {
 837                 size_t i;
 838
 839                 assert(vals->kind != BITFIELD);
 840                 vals->kind     = TARVAL;
 841                 vals->v.tarval = get_initializer_tarval_value(initializer);
 842                 assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval));
 843                 for(i = 1; i < get_type_size_bytes(type); ++i) {
 844                         vals[i].kind    = NORMAL;
 845                         vals[i].v.value = NULL;
 846                 }
 847                 return;
 848         }
 849         case IR_INITIALIZER_CONST: {
 850                 size_t i;
 851
 852                 assert(vals->kind != BITFIELD);
 853                 vals->kind    = NORMAL;
 854                 vals->v.value = get_initializer_const_value(initializer);
 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_COMPOUND: {
 862                 size_t i = 0;
 863                 size_t n = get_initializer_compound_n_entries(initializer);
 864
 865                 if(is_Array_type(type)) {
 866                         ir_type *element_type = get_array_element_type(type);
 867                         size_t   skip         = get_type_size_bytes(element_type);
 868                         size_t   alignment    = get_type_alignment_bytes(element_type);
 869                         size_t   misalign     = skip % alignment;
 870                         if(misalign != 0) {
 871                                 skip += alignment - misalign;
 872                         }
 873
 874                         for(i = 0; i < n; ++i) {
 875                                 ir_initializer_t *sub_initializer
 876                                         = get_initializer_compound_value(initializer, i);
 877
 878                                 dump_ir_initializer(vals, sub_initializer, element_type);
 879
 880                                 vals += skip;
 881                         }
 882                 } else {
 883                         size_t n_members, i;
 884                         assert(is_compound_type(type));
 885                         n_members = get_compound_n_members(type);
 886                         for(i = 0; i < n_members; ++i) {
 887                                 ir_entity        *member    = get_compound_member(type, i);
 888                                 size_t            offset    = get_entity_offset(member);
 889                                 ir_type          *subtype   = get_entity_type(member);
 890                                 ir_mode          *mode      = get_type_mode(subtype);
 891                                 ir_initializer_t *sub_initializer;
 892
 893                                 assert(i < get_initializer_compound_n_entries(initializer));
 894                                 sub_initializer
 895                                         = get_initializer_compound_value(initializer, i);
 896
 897                                 if(mode != NULL) {
 898                                         size_t offset_bits
 899                                                 = get_entity_offset_bits_remainder(member);
 900                                         size_t value_len   = get_mode_size_bits(mode);
 901
 902                                         if(offset_bits != 0 ||
 903                                                 (value_len != 8 && value_len != 16 && value_len != 32
 904                                                  && value_len != 64)) {
 905                                                 dump_bitfield(&vals[offset], offset_bits,
 906                                                               sub_initializer, subtype);
 907                                                 continue;
 908                                         }
 909                                 }
 910
 911                                 dump_ir_initializer(&vals[offset], sub_initializer, subtype);
 912                         }
 913                 }
 914
 915                 return;
 916         }
 917         }
 918         panic("invalid ir_initializer kind found");
 919 }
 920
 921 static void dump_initializer(be_gas_decl_env_t *env, ir_entity *entity)
 922 {
 923         const ir_initializer_t *initializer = entity->attr.initializer;
 924         ir_type                *type;
 925         normal_or_bitfield     *vals;
 926         size_t                  size;
 927         size_t                  k;
 928
 929         if(initializer_is_string_const(initializer)) {
 930                 dump_string_initializer(initializer);
 931                 return;
 932         }
 933
 934         type = get_entity_type(entity);
 935         size = get_initializer_size(initializer, type);
 936
 937         if (size == 0)
 938                 return;
 939
 940         /*
 941          * In the worst case, every initializer allocates one byte.
 942          * Moreover, initializer might be big, do not allocate on stack.
 943          */
 944         vals = xcalloc(size, sizeof(vals[0]));
 945
 946 #ifndef NDEBUG
 947         glob_vals = vals;
 948         max_vals  = size;
 949 #endif
 950
 951         dump_ir_initializer(vals, initializer, type);
 952
 953         /* now write values sorted */
 954         for (k = 0; k < size; ) {
 955                 int space     = 0;
 956                 int elem_size = 1;
 957                 if (vals[k].kind == NORMAL) {
 958                         if(vals[k].v.value != NULL) {
 959                                 dump_atomic_init(env, vals[k].v.value);
 960                                 elem_size = get_mode_size_bytes(get_irn_mode(vals[k].v.value));
 961                         } else {
 962                                 elem_size = 0;
 963                         }
 964                 } else if(vals[k].kind == TARVAL) {
 965                         tarval *tv   = vals[k].v.tarval;
 966                         size_t  size = get_mode_size_bytes(get_tarval_mode(tv));
 967
 968                         assert(tv != NULL);
 969
 970                         elem_size = size;
 971                         dump_size_type(size);
 972                         dump_arith_tarval(tv, size);
 973                         be_emit_char('\n');
 974                         be_emit_write_line();
 975                 } else {
 976                         assert(vals[k].kind == BITFIELD);
 977                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
 978                         be_emit_write_line();
 979                 }
 980
 981                 k += elem_size;
 982                 while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
 983                         ++space;
 984                         ++k;
 985                 }
 986
 987                 /* a gap */
 988                 if (space > 0) {
 989                         be_emit_irprintf("\t.skip\t%d\n", space);
 990                         be_emit_write_line();
 991                 }
 992         }
 993         xfree(vals);
 994 }
 995
 996 /**
 997  * Dump an initializer for a compound entity.
 998  */
 999 static void dump_compound_init(be_gas_decl_env_t *env, ir_entity *ent)
1000 {
1001         normal_or_bitfield *vals;
1002         int i, j, n;
1003         unsigned k, last_ofs;
1004
1005         if(ent->has_initializer) {
1006                 dump_initializer(env, ent);
1007                 return;
1008         }
1009
1010         n = get_compound_ent_n_values(ent);
1011
1012         /* Find the initializer size. Sorrily gcc support a nasty feature:
1013            The last field of a compound may be a flexible array. This allows
1014            initializers bigger than the type size. */
1015         last_ofs = get_type_size_bytes(get_entity_type(ent));
1016         for (i = 0; i < n; ++i) {
1017                 unsigned offset         = get_compound_ent_value_offset_bytes(ent, i);
1018                 unsigned bits_remainder = get_compound_ent_value_offset_bit_remainder(ent, i);
1019                 ir_node  *value         = get_compound_ent_value(ent, i);
1020                 unsigned value_len      = get_mode_size_bits(get_irn_mode(value));
1021
1022                 offset += (value_len + bits_remainder + 7) >> 3;
1023
1024                 if (offset > last_ofs) {
1025                         last_ofs = offset;
1026                 }
1027         }
1028
1029         /*
1030          * In the worst case, every initializer allocates one byte.
1031          * Moreover, initializer might be big, do not allocate on stack.
1032          */
1033         vals = xcalloc(last_ofs, sizeof(vals[0]));
1034
1035         /* collect the values and store them at the offsets */
1036         for (i = 0; i < n; ++i) {
1037                 unsigned offset      = get_compound_ent_value_offset_bytes(ent, i);
1038                 int      offset_bits = get_compound_ent_value_offset_bit_remainder(ent, i);
1039                 ir_node  *value      = get_compound_ent_value(ent, i);
1040                 int      value_len   = get_mode_size_bits(get_irn_mode(value));
1041
1042                 assert(offset_bits >= 0);
1043
1044                 if (offset_bits != 0 ||
1045                         (value_len != 8 && value_len != 16 && value_len != 32 && value_len != 64)) {
1046                         tarval *tv = get_atomic_init_tv(value);
1047                         unsigned char curr_bits, last_bits = 0;
1048                         if (tv == NULL) {
1049                                 panic("Couldn't get numeric value for bitfield initializer '%s'\n",
1050                                       get_entity_ld_name(ent));
1051                         }
1052                         /* normalize offset */
1053                         offset += offset_bits >> 3;
1054                         offset_bits &= 7;
1055
1056                         for (j = 0; value_len + offset_bits > 0; ++j) {
1057                                 assert(offset + j < last_ofs);
1058                                 assert(vals[offset + j].kind == BITFIELD || vals[offset + j].v.value == NULL);
1059                                 vals[offset + j].kind = BITFIELD;
1060                                 curr_bits = get_tarval_sub_bits(tv, j);
1061                                 vals[offset + j].v.bf_val |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
1062                                 value_len -= 8;
1063                                 last_bits = curr_bits;
1064                         }
1065                 } else {
1066                         int i;
1067
1068                         assert(offset < last_ofs);
1069                         assert(vals[offset].kind == NORMAL);
1070                         for (i = 1; i < value_len / 8; ++i) {
1071                                 assert(vals[offset + i].v.value == NULL);
1072                         }
1073                         vals[offset].v.value = value;
1074                 }
1075         }
1076
1077         /* now write them sorted */
1078         for (k = 0; k < last_ofs; ) {
1079                 int space = 0, skip = 0;
1080                 if (vals[k].kind == NORMAL) {
1081                         if(vals[k].v.value != NULL) {
1082                                 dump_atomic_init(env, vals[k].v.value);
1083                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
1084                         } else {
1085                                 space = 1;
1086                         }
1087                 } else {
1088                         assert(vals[k].kind == BITFIELD);
1089                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1090                 }
1091
1092                 ++k;
1093                 while (k < last_ofs && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1094                         ++space;
1095                         ++k;
1096                 }
1097                 space -= skip;
1098                 assert(space >= 0);
1099
1100                 /* a gap */
1101                 if (space > 0) {
1102                         be_emit_irprintf("\t.skip\t%d\n", space);
1103                         be_emit_write_line();
1104                 }
1105         }
1106         xfree(vals);
1107 }
1108
1109 static void emit_align(unsigned alignment)
1110 {
1111         if (!is_po2(alignment))
1112                 panic("alignment not a power of 2");
1113
1114         be_emit_irprintf(".p2align\t%u\n", log2_floor(alignment));
1115         be_emit_write_line();
1116 }
1117
1118 /**
1119  * Dump a global entity.
1120  *
1121  * @param env           the gas output environment
1122  * @param ent           the entity to be dumped
1123  */
1124 static void dump_global(be_gas_decl_env_t *env, ir_entity *ent)
1125 {
1126         ir_type          *type           = get_entity_type(ent);
1127         ident            *ld_ident       = get_entity_ld_ident(ent);
1128         unsigned          align          = get_type_alignment_bytes(type);
1129         int               emit_as_common = 0;
1130         be_gas_section_t  section        = env->section;
1131         ir_variability    variability    = get_entity_variability(ent);
1132         ir_visibility     visibility     = get_entity_visibility(ent);
1133
1134         if (is_Method_type(type) && section != GAS_SECTION_PIC_TRAMPOLINES) {
1135                 return;
1136         }
1137
1138         if (section != (be_gas_section_t) -1) {
1139                 emit_as_common = 0;
1140         } else if (variability == variability_constant) {
1141                 /* a constant entity, put it on the rdata */
1142                 section = GAS_SECTION_RODATA;
1143                 if (be_gas_flavour == GAS_FLAVOUR_MACH_O
1144                                 && ent_is_string_const(ent)) {
1145                         section = GAS_SECTION_CSTRING;
1146                 }
1147         } else if (variability == variability_uninitialized) {
1148                 /* uninitialized entity put it in bss segment */
1149                 section = GAS_SECTION_COMMON;
1150                 if (visibility != visibility_local)
1151                         emit_as_common = 1;
1152         } else {
1153                 section = GAS_SECTION_DATA;
1154         }
1155
1156         if(!emit_as_common) {
1157                 be_gas_emit_switch_section(section);
1158         }
1159
1160         be_dbg_variable(ent);
1161
1162         /* global or not global */
1163         if (visibility == visibility_external_visible && !emit_as_common) {
1164                 be_emit_cstring(".globl\t");
1165                 be_emit_ident(ld_ident);
1166                 be_emit_char('\n');
1167                 be_emit_write_line();
1168         } else if(visibility == visibility_external_allocated) {
1169                 be_emit_cstring(".globl\t");
1170                 be_emit_ident(ld_ident);
1171                 be_emit_char('\n');
1172                 be_emit_write_line();
1173                 /* we can return now... */
1174                 return;
1175         }
1176         /* alignment */
1177         if (align > 1 && !emit_as_common && section != GAS_SECTION_PIC_TRAMPOLINES
1178                         && section != GAS_SECTION_PIC_SYMBOLS) {
1179                 emit_align(align);
1180         }
1181
1182         if (!emit_as_common) {
1183                 be_emit_ident(ld_ident);
1184                 be_emit_cstring(":\n");
1185                 be_emit_write_line();
1186         }
1187
1188         if (variability == variability_uninitialized) {
1189                 if (emit_as_common) {
1190                         switch (be_gas_flavour) {
1191                         case GAS_FLAVOUR_ELF:
1192                         case GAS_FLAVOUR_MACH_O:
1193                         case GAS_FLAVOUR_YASM:
1194                                 be_emit_irprintf("\t.comm %s,%u,%u\n",
1195                                         get_id_str(ld_ident), get_type_size_bytes(type), align);
1196                                 be_emit_write_line();
1197                                 break;
1198                         case GAS_FLAVOUR_MINGW:
1199                                 be_emit_irprintf("\t.comm %s,%u # %u\n",
1200                                         get_id_str(ld_ident), get_type_size_bytes(type), align);
1201                                 be_emit_write_line();
1202                                 break;
1203                         }
1204                 } else if (section == GAS_SECTION_PIC_TRAMPOLINES) {
1205                         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
1206                                 be_emit_cstring("\t.indirect_symbol ");
1207                                 be_emit_ident(get_entity_ident(ent));
1208                                 be_emit_char('\n');
1209                                 be_emit_write_line();
1210                                 be_emit_cstring("\thlt ; hlt ; hlt ; hlt ; hlt\n");
1211                                 be_emit_write_line();
1212                         } else {
1213                                 panic("PIC trampolines not yet supported in this gas mode");
1214                         }
1215                 } else {
1216                         be_emit_irprintf("\t.space %u\n", get_type_size_bytes(type));
1217                         be_emit_write_line();
1218                 }
1219         } else {
1220                 if (is_atomic_entity(ent)) {
1221                         dump_atomic_init(env, get_atomic_ent_value(ent));
1222                 } else {
1223                         /* sort_compound_ent_values(ent); */
1224
1225                         switch (get_type_tpop_code(get_entity_type(ent))) {
1226                         case tpo_array:
1227                                 if (ent_is_string_const(ent))
1228                                         dump_string_cst(ent);
1229                                 else
1230                                         dump_compound_init(env, ent);
1231                                 break;
1232                         case tpo_struct:
1233                         case tpo_class:
1234                         case tpo_union:
1235                                 dump_compound_init(env, ent);
1236                                 break;
1237                         default:
1238                                 assert(0);
1239                         }
1240                 }
1241         }
1242 }
1243
1244 /**
1245  * Dumps declarations of global variables and the initialization code.
1246  *
1247  * @param gt                a global like type, either the global or the TLS one
1248  * @param env               an environment
1249  * @param only_emit_marked  if non-zero, external allocated entities that do not have
1250  *                          its visited flag set are ignored
1251  */
1252 static void be_gas_dump_globals(ir_type *gt, be_gas_decl_env_t *env,
1253                                 int only_emit_marked)
1254 {
1255         int i, n = get_compound_n_members(gt);
1256         waitq *worklist = new_waitq();
1257
1258         if (only_emit_marked) {
1259                 for (i = 0; i < n; i++) {
1260                         ir_entity *ent = get_compound_member(gt, i);
1261                         if (is_entity_backend_marked(ent) ||
1262                             get_entity_visibility(ent) != visibility_external_allocated) {
1263                                 waitq_put(worklist, ent);
1264                                 set_entity_backend_marked(ent, 1);
1265                         }
1266                 }
1267         } else {
1268                 for (i = 0; i < n; i++) {
1269                         ir_entity *ent = get_compound_member(gt, i);
1270                         set_entity_backend_marked(ent, 1);
1271                         waitq_put(worklist, ent);
1272                 }
1273         }
1274
1275         env->worklist = worklist;
1276
1277         while (!waitq_empty(worklist)) {
1278                 ir_entity *ent = waitq_get(worklist);
1279
1280                 dump_global(env, ent);
1281         }
1282
1283         del_waitq(worklist);
1284         env->worklist = NULL;
1285 }
1286
1287 /************************************************************************/
1288
1289 /* Generate all entities. */
1290 void be_gas_emit_decls(const be_main_env_t *main_env,
1291                        int only_emit_marked_entities)
1292 {
1293         be_gas_decl_env_t env;
1294         memset(&env, 0, sizeof(env));
1295
1296         env.main_env = main_env;
1297
1298         /* dump global type */
1299         env.section = (be_gas_section_t) -1;
1300         be_gas_dump_globals(get_glob_type(), &env, only_emit_marked_entities);
1301         env.section = GAS_SECTION_TLS;
1302         be_gas_dump_globals(get_tls_type(), &env, only_emit_marked_entities);
1303         env.section = GAS_SECTION_CONSTRUCTORS;
1304         be_gas_dump_globals(get_segment_type(IR_SEGMENT_CONSTRUCTORS), &env,
1305                             only_emit_marked_entities);
1306         env.section = GAS_SECTION_DESTRUCTORS;
1307         be_gas_dump_globals(get_segment_type(IR_SEGMENT_DESTRUCTORS), &env,
1308                             only_emit_marked_entities);
1309
1310         env.section = GAS_SECTION_PIC_SYMBOLS;
1311         be_gas_dump_globals(main_env->pic_symbols_type, &env,
1312                             only_emit_marked_entities);
1313
1314         if (get_compound_n_members(main_env->pic_trampolines_type) > 0) {
1315                 env.section = GAS_SECTION_PIC_TRAMPOLINES;
1316                 be_gas_dump_globals(main_env->pic_trampolines_type, &env,
1317                                     only_emit_marked_entities);
1318                 if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
1319                         be_emit_cstring("\t.subsections_via_symbols\n");
1320                         be_emit_write_line();
1321                 }
1322         }
1323 }