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