-removed junk
[libfirm] / ir / be / begnuas.c
1 /*
2  * Copyright (C) 1995-2008 University of Karlsruhe.  All right reserved.
3  *
4  * This file is part of libFirm.
5  *
6  * This file may be distributed and/or modified under the terms of the
7  * GNU General Public License version 2 as published by the Free Software
8  * Foundation and appearing in the file LICENSE.GPL included in the
9  * packaging of this file.
10  *
11  * Licensees holding valid libFirm Professional Edition licenses may use
12  * this file in accordance with the libFirm Commercial License.
13  * Agreement provided with the Software.
14  *
15  * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
16  * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17  * PURPOSE.
18  */
19
20 /**
21  * @file
22  * @brief       Dumps global variables and constants as gas assembler.
23  * @author      Christian Wuerdig, Matthias Braun
24  * @date        04.11.2005
25  * @version     $Id$
26  */
27 #include "config.h"
28
29 #include "begnuas.h"
30
31 #include <stdlib.h>
32 #include <string.h>
33 #include <ctype.h>
34 #include <assert.h>
35
36 #include "obst.h"
37 #include "tv.h"
38 #include "irnode.h"
39 #include "irprog.h"
40 #include "pdeq.h"
41 #include "entity_t.h"
42 #include "error.h"
43
44 #include "be_t.h"
45 #include "beemitter.h"
46 #include "be_dbgout.h"
47
48 /** by default, we generate assembler code for the Linux gas */
49 be_gas_flavour_t be_gas_flavour = GAS_FLAVOUR_ELF;
50
51 static be_gas_section_t current_section = (be_gas_section_t) -1;
52
53 /**
54  * Return the pseudo-instruction to be issued for a section switch
55  * depending on the current flavour.
56  *
57  * @param section  the section to switch to
58  *
59  * @return  the pseudo-instruction
60  */
61 static const char *get_section_name(be_gas_section_t section) {
62         static const char *text[GAS_FLAVOUR_LAST+1][GAS_SECTION_LAST+1] = {
63                 { /* GAS_FLAVOUR_ELF */
64                         ".section\t.text",
65                         ".section\t.data",
66                         ".section\t.rodata",
67                         ".section\t.bss",
68                         ".section\t.tbss,\"awT\",@nobits",
69                         ".section\t.ctors,\"aw\",@progbits",
70                         ".section\t.dtors,\"aw\",@progbits",
71                         NULL, /* no cstring section */
72                         NULL,
73                         NULL
74                 },
75                 { /* GAS_FLAVOUR_MINGW */
76                         ".section\t.text",
77                         ".section\t.data",
78                         ".section .rdata,\"dr\"",
79                         ".section\t.bss",
80                         ".section\t.tbss,\"awT\",@nobits",
81                         ".section\t.ctors,\"aw\",@progbits",
82                         ".section\t.dtors,\"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                         ".section\t.dtors,\"aw\",@progbits",
95                         NULL,
96                         NULL,
97                         NULL
98                 },
99                 { /* GAS_FLAVOUR_MACH_O */
100                         ".text",
101                         ".data",
102                         ".const",
103                         ".data",
104                         NULL,             /* TLS is not supported on Mach-O */
105                         ".mod_init_func",
106                         NULL,             /* TODO: how is this called? */
107                         ".cstring",
108                         ".section\t__IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_instructions,5",
109                         ".section\t__IMPORT,__pointers,non_lazy_symbol_pointers"
110                 }
111         };
112
113         assert((int) be_gas_flavour >= 0 && be_gas_flavour <= GAS_FLAVOUR_LAST);
114         assert((int) section >= 0 && section <= GAS_SECTION_LAST);
115         return text[be_gas_flavour][section];
116 }
117
118 void be_gas_emit_switch_section(be_gas_section_t section) {
119         if (current_section == section)
120                 return;
121
122         be_emit_char('\t');
123         be_emit_string(get_section_name(section));
124         be_emit_char('\n');
125         be_emit_write_line();
126         current_section = section;
127 }
128
129 void be_gas_emit_function_prolog(ir_entity *entity, unsigned alignment)
130 {
131         const char *name = get_entity_ld_name(entity);
132         const char *fill_byte = "";
133         unsigned maximum_skip;
134
135         be_gas_emit_switch_section(GAS_SECTION_TEXT);
136
137         /* write the begin line (used by scripts processing the assembler... */
138         be_emit_write_line();
139         be_emit_cstring("# -- Begin  ");
140         be_emit_string(name);
141         be_emit_char('\n');
142         be_emit_write_line();
143
144         /* gcc fills space between function with 0x90, no idea if this is needed */
145         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
146                 fill_byte = "0x90";
147         }
148
149         if (alignment > 0) {
150                 maximum_skip = (1 << alignment) - 1;
151                 be_emit_cstring("\t.p2align ");
152                 be_emit_irprintf("%u,%s,%u\n", alignment, fill_byte, maximum_skip);
153                 be_emit_write_line();
154         }
155         if (get_entity_visibility(entity) == visibility_external_visible) {
156                 be_emit_cstring(".globl ");
157                 be_emit_string(name);
158                 be_emit_char('\n');
159                 be_emit_write_line();
160         }
161
162         switch (be_gas_flavour) {
163         case GAS_FLAVOUR_ELF:
164                 be_emit_cstring("\t.type\t");
165                 be_emit_string(name);
166                 be_emit_cstring(", @function\n");
167                 be_emit_write_line();
168                 break;
169         case GAS_FLAVOUR_MINGW:
170                 be_emit_cstring("\t.def\t");
171                 be_emit_string(name);
172                 if (get_entity_visibility(entity) == visibility_external_visible) {
173                         be_emit_cstring(";\t.scl\t2;\t.type\t32;\t.endef\n");
174                 } else {
175                         be_emit_cstring(";\t.scl\t3;\t.type\t32;\t.endef\n");
176                 }
177                 be_emit_write_line();
178                 break;
179         case GAS_FLAVOUR_MACH_O:
180         case GAS_FLAVOUR_YASM:
181                 break;
182         }
183         be_emit_string(name);
184         be_emit_cstring(":\n");
185         be_emit_write_line();
186 }
187
188 void be_gas_emit_function_epilog(ir_entity *entity)
189 {
190         const char *name = get_entity_ld_name(entity);
191
192         if (be_gas_flavour == GAS_FLAVOUR_ELF) {
193                 be_emit_cstring("\t.size\t");
194                 be_emit_string(name);
195                 be_emit_cstring(", .-");
196                 be_emit_string(name);
197                 be_emit_char('\n');
198                 be_emit_write_line();
199         }
200
201         be_emit_cstring("# -- End  ");
202         be_emit_string(name);
203         be_emit_char('\n');
204         be_emit_write_line();
205 }
206
207 /**
208  * An environment containing all needed dumper data.
209  * Currently we create the file completely in memory first, then
210  * write it to the disk. This is an artifact from the old C-generating backend
211  * and even there NOT needed. So we might change it in the future.
212  */
213 typedef struct _be_gas_decl_env {
214         be_gas_section_t     section;
215         waitq               *worklist;           /**< A worklist we use to place not yet handled entities on. */
216 } be_gas_decl_env_t;
217
218 /************************************************************************/
219
220 /**
221  * Output a tarval.
222  *
223  * @param tv     the tarval
224  * @param bytes  the width of the tarvals value in bytes
225  */
226 static void dump_arith_tarval(tarval *tv, int bytes)
227 {
228         switch (bytes) {
229         case 1:
230                 be_emit_irprintf("0x%02x", get_tarval_sub_bits(tv, 0));
231                 return;
232
233         case 2:
234                 be_emit_irprintf("0x%02x%02x", get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
235                 return;
236
237         case 4:
238                 be_emit_irprintf("0x%02x%02x%02x%02x",
239                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
240                 return;
241
242         case 8:
243                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x",
244                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6), get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
245                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
246                 return;
247
248         case 12:
249                 /* Beware: Mixed endian output!  One little endian number emitted as
250                  * three longs.  Each long initializer is written in big endian. */
251                 be_emit_irprintf(
252                         "\t.long\t0x%02x%02x%02x%02x\n"
253                         "\t.long\t0x%02x%02x%02x%02x\n"
254                         "\t.long\t0x%02x%02x%02x%02x",
255                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
256                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0),
257                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
258                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
259                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
260                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8)
261                 );
262                 return;
263
264         case 16:
265                 be_emit_irprintf(
266                         "\t.long\t0x%02x%02x%02x%02x0x%02x%02x%02x%02x0x%02x%02x%02x%02x0x%02x%02x%02x%02x",
267                         get_tarval_sub_bits(tv, 15), get_tarval_sub_bits(tv, 16),
268                         get_tarval_sub_bits(tv, 13), get_tarval_sub_bits(tv, 12),
269                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
270                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8),
271                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
272                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
273                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
274                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0)
275                 );
276                 return;
277         }
278
279         panic("Can't dump a tarval with %d bytes", bytes);
280 }
281
282 /**
283  * Return the label prefix for labeled blocks.
284  */
285 const char *be_gas_block_label_prefix(void) {
286         return ".LG";
287 }
288
289 /**
290  * Return the label prefix for labeled instructions.
291  */
292 const char *be_gas_insn_label_prefix(void) {
293         return ".LE";
294 }
295
296 /**
297  * Dump a label.
298  */
299 static void dump_label(ir_label_t label) {
300         be_emit_irprintf("%s%lu", be_gas_block_label_prefix(), label);
301 }
302
303 /**
304  * Return the tarval of an atomic initializer.
305  *
306  * @param init  a node representing the initializer (on the const code irg)
307  *
308  * @return the tarval
309  */
310 static tarval *get_atomic_init_tv(ir_node *init)
311 {
312         for (;;) {
313                 ir_mode *mode = get_irn_mode(init);
314
315                 switch (get_irn_opcode(init)) {
316
317                 case iro_Cast:
318                         init = get_Cast_op(init);
319                         continue;
320
321                 case iro_Conv:
322                         init = get_Conv_op(init);
323                         continue;
324
325                 case iro_Const:
326                         return get_Const_tarval(init);
327
328                 case iro_SymConst:
329                         switch (get_SymConst_kind(init)) {
330                         case symconst_type_size:
331                                 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(init)), mode);
332
333                         case symconst_type_align:
334                                 return new_tarval_from_long(get_type_alignment_bytes(get_SymConst_type(init)), mode);
335
336                         case symconst_ofs_ent:
337                                 return new_tarval_from_long(get_entity_offset(get_SymConst_entity(init)), mode);
338
339                         case symconst_enum_const:
340                                 return get_enumeration_value(get_SymConst_enum(init));
341
342                         case symconst_label:
343                                 return NULL;
344
345                         default:
346                                 return NULL;
347                         }
348
349                 default:
350                         return NULL;
351                 }
352         }
353 }
354
355 /**
356  * Dump an atomic value.
357  *
358  * @param env   the gas output environment
359  * @param init  a node representing the atomic value (on the const code irg)
360  */
361 static void do_dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
362 {
363         ir_mode *mode = get_irn_mode(init);
364         int bytes     = get_mode_size_bytes(mode);
365         tarval *tv;
366         ir_label_t label;
367         ir_entity *ent;
368
369         init = skip_Id(init);
370
371         switch (get_irn_opcode(init)) {
372         case iro_Cast:
373                 do_dump_atomic_init(env, get_Cast_op(init));
374                 return;
375
376         case iro_Conv:
377                 do_dump_atomic_init(env, get_Conv_op(init));
378                 return;
379
380         case iro_Const:
381                 tv = get_Const_tarval(init);
382
383                 /* it's a arithmetic value */
384                 dump_arith_tarval(tv, bytes);
385                 return;
386
387         case iro_SymConst:
388                 switch (get_SymConst_kind(init)) {
389                 case symconst_addr_name:
390                         be_emit_ident(get_SymConst_name(init));
391                         break;
392
393                 case symconst_addr_ent:
394                         ent = get_SymConst_entity(init);
395                         if (!is_entity_backend_marked(ent)) {
396                                 waitq_put(env->worklist, ent);
397                                 set_entity_backend_marked(ent, 1);
398                         }
399                         be_emit_ident(get_entity_ld_ident(ent));
400                         break;
401
402                 case symconst_ofs_ent:
403                         ent = get_SymConst_entity(init);
404 #if 0       /* not needed, is it? */
405                         if (!is_entity_backend_marked(ent)) {
406                                 waitq_put(env->worklist, ent);
407                                 set_entity_backend_marked(ent, 1);
408                         }
409 #endif
410                         be_emit_irprintf("%d", get_entity_offset(ent));
411                         break;
412
413                 case symconst_type_size:
414                         be_emit_irprintf("%u", get_type_size_bytes(get_SymConst_type(init)));
415                         break;
416
417                 case symconst_type_align:
418                         be_emit_irprintf("%u", get_type_alignment_bytes(get_SymConst_type(init)));
419                         break;
420
421                 case symconst_enum_const:
422                         tv = get_enumeration_value(get_SymConst_enum(init));
423                         dump_arith_tarval(tv, bytes);
424                         break;
425
426                 case symconst_label:
427                         label = get_SymConst_label(init);
428                         dump_label(label);
429                         break;
430
431                 default:
432                         assert(!"dump_atomic_init(): don't know how to init from this SymConst");
433                 }
434                 return;
435
436         case iro_Add:
437                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
438                         panic("Constant must be int or pointer for '+' to work");
439                 }
440                 do_dump_atomic_init(env, get_Add_left(init));
441                 be_emit_cstring(" + ");
442                 do_dump_atomic_init(env, get_Add_right(init));
443                 return;
444
445         case iro_Sub:
446                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
447                         panic("Constant must be int or pointer for '-' to work");
448                 }
449                 do_dump_atomic_init(env, get_Sub_left(init));
450                 be_emit_cstring(" - ");
451                 do_dump_atomic_init(env, get_Sub_right(init));
452                 return;
453
454         case iro_Mul:
455                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
456                         panic("Constant must be int or pointer for '*' to work");
457                 }
458                 do_dump_atomic_init(env, get_Mul_left(init));
459                 be_emit_cstring(" * ");
460                 do_dump_atomic_init(env, get_Mul_right(init));
461                 return;
462
463         default:
464                 panic("dump_atomic_init(): unsupported IR-node %+F", init);
465         }
466 }
467
468 /**
469  * Dumps the type for given size (.byte, .long, ...)
470  *
471  * @param size  the size in bytes
472  */
473 static void dump_size_type(size_t size) {
474         switch (size) {
475         case 1:
476                 be_emit_cstring("\t.byte\t");
477                 break;
478
479         case 2:
480                 be_emit_cstring("\t.word\t");
481                 break;
482
483         case 4:
484                 be_emit_cstring("\t.long\t");
485                 break;
486
487         case 8:
488                 be_emit_cstring("\t.quad\t");
489                 break;
490
491         case 10:
492         case 12:
493                 /* handled in arith */
494                 break;
495
496         case 16:
497                 be_emit_cstring("\t.octa\t");
498                 break;
499
500         default:
501                 panic("Try to dump a type with %u bytes", (unsigned)size);
502         }
503 }
504
505 /**
506  * Emit an atomic value.
507  *
508  * @param env   the gas output environment
509  * @param init  a node representing the atomic value (on the const code irg)
510  */
511 static void dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
512 {
513         ir_mode *mode = get_irn_mode(init);
514         int bytes     = get_mode_size_bytes(mode);
515
516         dump_size_type(bytes);
517         do_dump_atomic_init(env, init);
518         be_emit_char('\n');
519         be_emit_write_line();
520 }
521
522 /************************************************************************/
523 /* Routines to dump global variables                                    */
524 /************************************************************************/
525
526 static int initializer_is_string_const(const ir_initializer_t *initializer)
527 {
528         size_t i, len;
529         int found_printable = 0;
530
531         if (initializer->kind != IR_INITIALIZER_COMPOUND)
532                 return 0;
533
534         len = initializer->compound.n_initializers;
535         if (len < 1)
536                 return 0;
537         for (i = 0; i < len; ++i) {
538                 int               c;
539                 tarval           *tv;
540                 ir_mode          *mode;
541                 ir_initializer_t *sub_initializer
542                         = initializer->compound.initializers[i];
543
544                 if (sub_initializer->kind != IR_INITIALIZER_TARVAL)
545                         return 0;
546
547                 tv   = sub_initializer->tarval.value;
548                 mode = get_tarval_mode(tv);
549
550                 if (!mode_is_int(mode)
551                                 || get_mode_size_bits(mode) != get_mode_size_bits(mode_Bs))
552                         return 0;
553
554                 c = get_tarval_long(tv);
555                 if (isgraph(c) || isspace(c))
556                         found_printable = 1;
557                 else if (c != 0)
558                         return 0;
559
560                 if (i == len - 1 && c != '\0')
561                         return 0;
562         }
563
564         return found_printable;
565 }
566
567 /**
568  * Determine if an entity is a string constant
569  * @param ent The entity
570  * @return 1 if it is a string constant, 0 otherwise
571  */
572 static int ent_is_string_const(ir_entity *ent)
573 {
574         ir_type *type, *element_type;
575         ir_mode *mode;
576         int i, c, n;
577         int found_printable = 0;
578
579         type = get_entity_type(ent);
580
581         /* if it's an array */
582         if (!is_Array_type(type))
583                 return 0;
584
585         element_type = get_array_element_type(type);
586
587         /* and the array's element type is primitive */
588         if (!is_Primitive_type(element_type))
589                 return 0;
590
591         /* and the mode of the element type is an int of
592          * the same size as the byte mode */
593         mode = get_type_mode(element_type);
594         if (!mode_is_int(mode)
595                 || get_mode_size_bits(mode) != get_mode_size_bits(mode_Bs))
596                 return 0;
597
598         if (ent->has_initializer) {
599                 /* TODO */
600                 return 0;
601         } else {
602                 /* if it contains only printable chars and a 0 at the end */
603                 n = get_compound_ent_n_values(ent);
604                 for (i = 0; i < n; ++i) {
605                         ir_node *irn = get_compound_ent_value(ent, i);
606                         if (! is_Const(irn))
607                                 return 0;
608
609                         c = (int) get_tarval_long(get_Const_tarval(irn));
610
611                         if (isgraph(c) || isspace(c))
612                                 found_printable = 1;
613                         else if (c != 0)
614                                 return 0;
615
616                         if (i == n - 1 && c != '\0')
617                                 return 0;
618                 }
619         }
620
621         /* then we can emit it as a string constant */
622         return found_printable;
623 }
624
625 /**
626  * Dump a string constant.
627  * No checks are made!!
628  *
629  * @param ent  The entity to dump.
630  */
631 static void dump_string_cst(ir_entity *ent)
632 {
633         int      i, len;
634         int      output_len;
635         ir_type *type;
636         int      type_size;
637         int      remaining_space;
638
639         len        = get_compound_ent_n_values(ent);
640         output_len = len;
641         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
642                 be_emit_cstring("\t.ascii \"");
643         } else {
644                 be_emit_cstring("\t.string \"");
645                 output_len -= 1;
646         }
647
648         for (i = 0; i < output_len; ++i) {
649                 ir_node *irn;
650                 int c;
651
652                 irn = get_compound_ent_value(ent, i);
653                 c = (int) get_tarval_long(get_Const_tarval(irn));
654
655                 switch (c) {
656                 case '"' : be_emit_cstring("\\\""); break;
657                 case '\n': be_emit_cstring("\\n"); break;
658                 case '\r': be_emit_cstring("\\r"); break;
659                 case '\t': be_emit_cstring("\\t"); break;
660                 case '\\': be_emit_cstring("\\\\"); break;
661                 default  :
662                         if (isprint(c))
663                                 be_emit_char(c);
664                         else
665                                 be_emit_irprintf("\\%o", c);
666                         break;
667                 }
668         }
669         be_emit_cstring("\"\n");
670         be_emit_write_line();
671
672         type            = get_entity_type(ent);
673         type_size       = get_type_size_bytes(type);
674         remaining_space = type_size - len;
675         assert(remaining_space >= 0);
676         if (remaining_space > 0) {
677                 be_emit_irprintf("\t.space\t%d\n", remaining_space);
678         }
679 }
680
681 static void dump_string_initializer(const ir_initializer_t *initializer)
682 {
683         size_t i, len;
684
685         len = initializer->compound.n_initializers;
686         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
687                 be_emit_cstring("\t.ascii \"");
688         } else {
689                 be_emit_cstring("\t.string \"");
690                 len -= 1;
691         }
692
693         for (i = 0; i < len; ++i) {
694                 const ir_initializer_t *sub_initializer
695                         = get_initializer_compound_value(initializer, i);
696
697                 tarval *tv = get_initializer_tarval_value(sub_initializer);
698                 int     c  = get_tarval_long(tv);
699
700                 switch (c) {
701                 case '"' : be_emit_cstring("\\\""); break;
702                 case '\n': be_emit_cstring("\\n"); break;
703                 case '\r': be_emit_cstring("\\r"); break;
704                 case '\t': be_emit_cstring("\\t"); break;
705                 case '\\': be_emit_cstring("\\\\"); break;
706                 default  :
707                         if (isprint(c))
708                                 be_emit_char(c);
709                         else
710                                 be_emit_irprintf("\\%o", c);
711                         break;
712                 }
713         }
714         be_emit_cstring("\"\n");
715         be_emit_write_line();
716 }
717
718 enum normal_or_bitfield_kind {
719         NORMAL = 0,
720         TARVAL,
721         BITFIELD
722 };
723
724 typedef struct {
725         enum normal_or_bitfield_kind kind;
726         union {
727                 ir_node       *value;
728                 tarval        *tarval;
729                 unsigned char  bf_val;
730         } v;
731 } normal_or_bitfield;
732
733 static int is_type_variable_size(ir_type *type)
734 {
735         (void) type;
736         /* TODO */
737         return 0;
738 }
739
740 static size_t get_initializer_size(const ir_initializer_t *initializer,
741                                    ir_type *type)
742 {
743         switch (get_initializer_kind(initializer)) {
744         case IR_INITIALIZER_TARVAL: {
745                 assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type));
746                 return get_type_size_bytes(type);
747         }
748         case IR_INITIALIZER_CONST:
749         case IR_INITIALIZER_NULL:
750                 return get_type_size_bytes(type);
751         case IR_INITIALIZER_COMPOUND: {
752                 if (!is_type_variable_size(type)) {
753                         return get_type_size_bytes(type);
754                 } else {
755                         unsigned n_entries
756                                 = get_initializer_compound_n_entries(initializer);
757                         unsigned i;
758                         unsigned initializer_size = get_type_size_bytes(type);
759                         for (i = 0; i < n_entries; ++i) {
760                                 ir_entity *entity = get_compound_member(type, i);
761                                 ir_type   *type   = get_entity_type(entity);
762
763                                 const ir_initializer_t *sub_initializer
764                                         = get_initializer_compound_value(initializer, i);
765
766                                 unsigned offset = get_entity_offset(entity);
767                                 unsigned size   = get_initializer_size(sub_initializer, type);
768
769                                 if (offset + size > initializer_size) {
770                                         initializer_size = offset + size;
771                                 }
772                         }
773                         return initializer_size;
774                 }
775         }
776         }
777
778         panic("found invalid initializer");
779 }
780
781 #ifndef NDEBUG
782 static normal_or_bitfield *glob_vals;
783 static size_t              max_vals;
784 #endif
785
786 static void dump_bitfield(normal_or_bitfield *vals, size_t offset_bits,
787                           const ir_initializer_t *initializer, ir_type *type)
788 {
789         unsigned char  last_bits = 0;
790         ir_mode       *mode      = get_type_mode(type);
791         tarval        *tv        = NULL;
792         unsigned char  curr_bits;
793         int            value_len;
794         int            j;
795
796         switch (get_initializer_kind(initializer)) {
797         case IR_INITIALIZER_NULL:
798                 return;
799         case IR_INITIALIZER_TARVAL:
800                 tv = get_initializer_tarval_value(initializer);
801                 break;
802         case IR_INITIALIZER_CONST: {
803                 ir_node *node = get_initializer_const_value(initializer);
804                 if (!is_Const(node)) {
805                         panic("bitfield initializer not a Const node");
806                 }
807                 tv = get_Const_tarval(node);
808                 break;
809         }
810         case IR_INITIALIZER_COMPOUND:
811                 panic("bitfield initializer is compound");
812         }
813         if (tv == NULL) {
814                 panic("Couldn't get numeric value for bitfield initializer");
815         }
816         tv = tarval_convert_to(tv, get_type_mode(type));
817
818         /* normalize offset */
819         vals        += offset_bits >> 3;
820         offset_bits &= 7;
821         value_len    = get_mode_size_bits(mode);
822
823         /* combine bits with existing bits */
824         for (j = 0; value_len + (int) offset_bits > 0; ++j) {
825                 assert((size_t) (vals - glob_vals) + j < max_vals);
826                 assert(vals[j].kind == BITFIELD ||
827                                 (vals[j].kind == NORMAL && vals[j].v.value == NULL));
828                 vals[j].kind = BITFIELD;
829                 curr_bits    = get_tarval_sub_bits(tv, j);
830                 vals[j].v.bf_val
831                         |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
832                 value_len -= 8;
833                 last_bits = curr_bits;
834         }
835 }
836
837 static void dump_ir_initializer(normal_or_bitfield *vals,
838                                 const ir_initializer_t *initializer,
839                                 ir_type *type)
840 {
841         assert((size_t) (vals - glob_vals) < max_vals);
842
843         switch (get_initializer_kind(initializer)) {
844         case IR_INITIALIZER_NULL:
845                 return;
846         case IR_INITIALIZER_TARVAL: {
847                 size_t i;
848
849                 assert(vals->kind != BITFIELD);
850                 vals->kind     = TARVAL;
851                 vals->v.tarval = get_initializer_tarval_value(initializer);
852                 assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval));
853                 for (i = 1; i < get_type_size_bytes(type); ++i) {
854                         vals[i].kind    = NORMAL;
855                         vals[i].v.value = NULL;
856                 }
857                 return;
858         }
859         case IR_INITIALIZER_CONST: {
860                 size_t i;
861
862                 assert(vals->kind != BITFIELD);
863                 vals->kind    = NORMAL;
864                 vals->v.value = get_initializer_const_value(initializer);
865                 for (i = 1; i < get_type_size_bytes(type); ++i) {
866                         vals[i].kind    = NORMAL;
867                         vals[i].v.value = NULL;
868                 }
869                 return;
870         }
871         case IR_INITIALIZER_COMPOUND: {
872                 size_t i = 0;
873                 size_t n = get_initializer_compound_n_entries(initializer);
874
875                 if (is_Array_type(type)) {
876                         ir_type *element_type = get_array_element_type(type);
877                         size_t   skip         = get_type_size_bytes(element_type);
878                         size_t   alignment    = get_type_alignment_bytes(element_type);
879                         size_t   misalign     = skip % alignment;
880                         if (misalign != 0) {
881                                 skip += alignment - misalign;
882                         }
883
884                         for (i = 0; i < n; ++i) {
885                                 ir_initializer_t *sub_initializer
886                                         = get_initializer_compound_value(initializer, i);
887
888                                 dump_ir_initializer(vals, sub_initializer, element_type);
889
890                                 vals += skip;
891                         }
892                 } else {
893                         size_t n_members, i;
894                         assert(is_compound_type(type));
895                         n_members = get_compound_n_members(type);
896                         for (i = 0; i < n_members; ++i) {
897                                 ir_entity        *member    = get_compound_member(type, i);
898                                 size_t            offset    = get_entity_offset(member);
899                                 ir_type          *subtype   = get_entity_type(member);
900                                 ir_mode          *mode      = get_type_mode(subtype);
901                                 ir_initializer_t *sub_initializer;
902
903                                 assert(i < get_initializer_compound_n_entries(initializer));
904                                 sub_initializer
905                                         = get_initializer_compound_value(initializer, i);
906
907                                 if (mode != NULL) {
908                                         size_t offset_bits
909                                                 = get_entity_offset_bits_remainder(member);
910                                         size_t value_len   = get_mode_size_bits(mode);
911
912                                         if (offset_bits != 0 ||
913                                                 (value_len != 8 && value_len != 16 && value_len != 32
914                                                  && value_len != 64)) {
915                                                 dump_bitfield(&vals[offset], offset_bits,
916                                                               sub_initializer, subtype);
917                                                 continue;
918                                         }
919                                 }
920
921                                 dump_ir_initializer(&vals[offset], sub_initializer, subtype);
922                         }
923                 }
924
925                 return;
926         }
927         }
928         panic("invalid ir_initializer kind found");
929 }
930
931 static void dump_initializer(be_gas_decl_env_t *env, ir_entity *entity)
932 {
933         const ir_initializer_t *initializer = entity->attr.initializer;
934         ir_type                *type;
935         normal_or_bitfield     *vals;
936         size_t                  size;
937         size_t                  k;
938
939         if (initializer_is_string_const(initializer)) {
940                 dump_string_initializer(initializer);
941                 return;
942         }
943
944         type = get_entity_type(entity);
945         size = get_initializer_size(initializer, type);
946
947         if (size == 0)
948                 return;
949
950         /*
951          * In the worst case, every initializer allocates one byte.
952          * Moreover, initializer might be big, do not allocate on stack.
953          */
954         vals = XMALLOCNZ(normal_or_bitfield, size);
955
956 #ifndef NDEBUG
957         glob_vals = vals;
958         max_vals  = size;
959 #endif
960
961         dump_ir_initializer(vals, initializer, type);
962
963         /* now write values sorted */
964         for (k = 0; k < size; ) {
965                 int space     = 0;
966                 int elem_size = 1;
967                 if (vals[k].kind == NORMAL) {
968                         if (vals[k].v.value != NULL) {
969                                 dump_atomic_init(env, vals[k].v.value);
970                                 elem_size = get_mode_size_bytes(get_irn_mode(vals[k].v.value));
971                         } else {
972                                 elem_size = 0;
973                         }
974                 } else if (vals[k].kind == TARVAL) {
975                         tarval *tv   = vals[k].v.tarval;
976                         size_t  size = get_mode_size_bytes(get_tarval_mode(tv));
977
978                         assert(tv != NULL);
979
980                         elem_size = size;
981                         dump_size_type(size);
982                         dump_arith_tarval(tv, size);
983                         be_emit_char('\n');
984                         be_emit_write_line();
985                 } else {
986                         assert(vals[k].kind == BITFIELD);
987                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
988                         be_emit_write_line();
989                 }
990
991                 k += elem_size;
992                 while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
993                         ++space;
994                         ++k;
995                 }
996
997                 /* a gap */
998                 if (space > 0) {
999                         be_emit_irprintf("\t.space\t%d\n", space);
1000                         be_emit_write_line();
1001                 }
1002         }
1003         xfree(vals);
1004 }
1005
1006 /**
1007  * Dump an initializer for a compound entity.
1008  */
1009 static void dump_compound_init(be_gas_decl_env_t *env, ir_entity *ent)
1010 {
1011         normal_or_bitfield *vals;
1012         int i, j, n;
1013         unsigned k, last_ofs;
1014
1015         if (ent->has_initializer) {
1016                 dump_initializer(env, ent);
1017                 return;
1018         }
1019
1020         n = get_compound_ent_n_values(ent);
1021
1022         /* Find the initializer size. Sorrily gcc support a nasty feature:
1023            The last field of a compound may be a flexible array. This allows
1024            initializers bigger than the type size. */
1025         last_ofs = get_type_size_bytes(get_entity_type(ent));
1026         for (i = 0; i < n; ++i) {
1027                 unsigned offset         = get_compound_ent_value_offset_bytes(ent, i);
1028                 unsigned bits_remainder = get_compound_ent_value_offset_bit_remainder(ent, i);
1029                 ir_node  *value         = get_compound_ent_value(ent, i);
1030                 unsigned value_len      = get_mode_size_bits(get_irn_mode(value));
1031
1032                 offset += (value_len + bits_remainder + 7) >> 3;
1033
1034                 if (offset > last_ofs) {
1035                         last_ofs = offset;
1036                 }
1037         }
1038
1039         /*
1040          * In the worst case, every initializer allocates one byte.
1041          * Moreover, initializer might be big, do not allocate on stack.
1042          */
1043         vals = XMALLOCNZ(normal_or_bitfield, last_ofs);
1044
1045         /* collect the values and store them at the offsets */
1046         for (i = 0; i < n; ++i) {
1047                 unsigned offset      = get_compound_ent_value_offset_bytes(ent, i);
1048                 int      offset_bits = get_compound_ent_value_offset_bit_remainder(ent, i);
1049                 ir_node  *value      = get_compound_ent_value(ent, i);
1050                 int      value_len   = get_mode_size_bits(get_irn_mode(value));
1051
1052                 assert(offset_bits >= 0);
1053
1054                 if (offset_bits != 0 ||
1055                         (value_len != 8 && value_len != 16 && value_len != 32 && value_len != 64)) {
1056                         tarval *tv = get_atomic_init_tv(value);
1057                         unsigned char curr_bits, last_bits = 0;
1058                         if (tv == NULL) {
1059                                 panic("Couldn't get numeric value for bitfield initializer '%s'",
1060                                       get_entity_ld_name(ent));
1061                         }
1062                         /* normalize offset */
1063                         offset += offset_bits >> 3;
1064                         offset_bits &= 7;
1065
1066                         for (j = 0; value_len + offset_bits > 0; ++j) {
1067                                 assert(offset + j < last_ofs);
1068                                 assert(vals[offset + j].kind == BITFIELD || vals[offset + j].v.value == NULL);
1069                                 vals[offset + j].kind = BITFIELD;
1070                                 curr_bits = get_tarval_sub_bits(tv, j);
1071                                 vals[offset + j].v.bf_val |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
1072                                 value_len -= 8;
1073                                 last_bits = curr_bits;
1074                         }
1075                 } else {
1076                         int i;
1077
1078                         assert(offset < last_ofs);
1079                         assert(vals[offset].kind == NORMAL);
1080                         for (i = 1; i < value_len / 8; ++i) {
1081                                 assert(vals[offset + i].v.value == NULL);
1082                         }
1083                         vals[offset].v.value = value;
1084                 }
1085         }
1086
1087         /* now write them sorted */
1088         for (k = 0; k < last_ofs; ) {
1089                 int space = 0, skip = 0;
1090                 if (vals[k].kind == NORMAL) {
1091                         if (vals[k].v.value != NULL) {
1092                                 dump_atomic_init(env, vals[k].v.value);
1093                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
1094                         } else {
1095                                 space = 1;
1096                         }
1097                 } else {
1098                         assert(vals[k].kind == BITFIELD);
1099                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1100                 }
1101
1102                 ++k;
1103                 while (k < last_ofs && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1104                         ++space;
1105                         ++k;
1106                 }
1107                 space -= skip;
1108                 assert(space >= 0);
1109
1110                 /* a gap */
1111                 if (space > 0) {
1112                         be_emit_irprintf("\t.space\t%d\n", space);
1113                         be_emit_write_line();
1114                 }
1115         }
1116         xfree(vals);
1117 }
1118
1119 static void emit_align(unsigned alignment)
1120 {
1121         if (!is_po2(alignment))
1122                 panic("alignment not a power of 2");
1123
1124         be_emit_irprintf("\t.p2align\t%u\n", log2_floor(alignment));
1125         be_emit_write_line();
1126 }
1127
1128 /**
1129  * Dump a global entity.
1130  *
1131  * @param env           the gas output environment
1132  * @param ent           the entity to be dumped
1133  */
1134 static void dump_global(be_gas_decl_env_t *env, ir_entity *ent)
1135 {
1136         ir_type          *type           = get_entity_type(ent);
1137         ident            *ld_ident       = get_entity_ld_ident(ent);
1138         unsigned          align          = get_type_alignment_bytes(type);
1139         int               emit_as_common = 0;
1140         be_gas_section_t  section        = env->section;
1141         ir_variability    variability    = get_entity_variability(ent);
1142         ir_visibility     visibility     = get_entity_visibility(ent);
1143
1144         if (is_Method_type(type) && section != GAS_SECTION_PIC_TRAMPOLINES) {
1145                 return;
1146         }
1147
1148         if (section != (be_gas_section_t) -1) {
1149                 emit_as_common = 0;
1150         } else if (variability == variability_constant) {
1151                 /* a constant entity, put it on the rdata */
1152                 section = GAS_SECTION_RODATA;
1153                 if (be_gas_flavour == GAS_FLAVOUR_MACH_O
1154                                 && ent_is_string_const(ent)) {
1155                         section = GAS_SECTION_CSTRING;
1156                 }
1157         } else if (variability == variability_uninitialized) {
1158                 /* uninitialized entity put it in bss segment */
1159                 section = GAS_SECTION_COMMON;
1160                 if (visibility != visibility_local)
1161                         emit_as_common = 1;
1162         } else {
1163                 section = GAS_SECTION_DATA;
1164         }
1165
1166         if (!emit_as_common) {
1167                 be_gas_emit_switch_section(section);
1168         }
1169
1170         be_dbg_variable(ent);
1171
1172         /* global or not global */
1173         if (visibility == visibility_external_visible && !emit_as_common) {
1174                 be_emit_cstring(".globl\t");
1175                 be_emit_ident(ld_ident);
1176                 be_emit_char('\n');
1177                 be_emit_write_line();
1178         } else if (visibility == visibility_external_allocated) {
1179                 be_emit_cstring(".globl\t");
1180                 be_emit_ident(ld_ident);
1181                 be_emit_char('\n');
1182                 be_emit_write_line();
1183                 /* we can return now... */
1184                 return;
1185         }
1186         /* alignment */
1187         if (align > 1 && !emit_as_common && section != GAS_SECTION_PIC_TRAMPOLINES
1188                         && section != GAS_SECTION_PIC_SYMBOLS) {
1189                 emit_align(align);
1190         }
1191
1192         if (visibility != visibility_external_allocated && !emit_as_common
1193                         && be_gas_flavour == GAS_FLAVOUR_ELF) {
1194                 be_emit_cstring("\t.type\t");
1195                 be_emit_ident(ld_ident);
1196                 be_emit_cstring(", @object\n\t.size\t");
1197                 be_emit_ident(ld_ident);
1198                 be_emit_irprintf(", %u\n", get_type_size_bytes(type));
1199         }
1200
1201         if (!emit_as_common) {
1202                 be_emit_ident(ld_ident);
1203                 be_emit_cstring(":\n");
1204                 be_emit_write_line();
1205         }
1206
1207         if (variability == variability_uninitialized) {
1208                 if (emit_as_common) {
1209                         switch (be_gas_flavour) {
1210                         case GAS_FLAVOUR_ELF:
1211                         case GAS_FLAVOUR_MACH_O:
1212                         case GAS_FLAVOUR_YASM:
1213                                 be_emit_irprintf("\t.comm %s,%u,%u\n",
1214                                         get_id_str(ld_ident), get_type_size_bytes(type), align);
1215                                 be_emit_write_line();
1216                                 break;
1217                         case GAS_FLAVOUR_MINGW:
1218                                 be_emit_irprintf("\t.comm %s,%u # %u\n",
1219                                         get_id_str(ld_ident), get_type_size_bytes(type), align);
1220                                 be_emit_write_line();
1221                                 break;
1222                         }
1223                 } else if (section == GAS_SECTION_PIC_TRAMPOLINES
1224                                 || section == GAS_SECTION_PIC_SYMBOLS) {
1225                         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
1226                                 be_emit_cstring("\t.indirect_symbol ");
1227                                 be_emit_ident(get_entity_ident(ent));
1228                                 be_emit_char('\n');
1229                                 be_emit_write_line();
1230                                 if (section == GAS_SECTION_PIC_TRAMPOLINES) {
1231                                         be_emit_cstring("\thlt ; hlt ; hlt ; hlt ; hlt\n");
1232                                         be_emit_write_line();
1233                                 } else {
1234                                         assert(section == GAS_SECTION_PIC_SYMBOLS);
1235                                         be_emit_cstring("\t.long 0\n");
1236                                         be_emit_write_line();
1237                                 }
1238                         } else {
1239                                 panic("PIC trampolines not yet supported in this gas mode");
1240                         }
1241                 } else {
1242                         be_emit_irprintf("\t.space %u\n", get_type_size_bytes(type));
1243                         be_emit_write_line();
1244                 }
1245         } else {
1246                 if (is_atomic_entity(ent)) {
1247                         dump_atomic_init(env, get_atomic_ent_value(ent));
1248                 } else {
1249                         /* sort_compound_ent_values(ent); */
1250
1251                         switch (get_type_tpop_code(get_entity_type(ent))) {
1252                         case tpo_array:
1253                                 if (ent_is_string_const(ent))
1254                                         dump_string_cst(ent);
1255                                 else
1256                                         dump_compound_init(env, ent);
1257                                 break;
1258                         case tpo_struct:
1259                         case tpo_class:
1260                         case tpo_union:
1261                                 dump_compound_init(env, ent);
1262                                 break;
1263                         default:
1264                                 panic("Unimplemented type kind in dump_global()");
1265                         }
1266                 }
1267         }
1268 }
1269
1270 /**
1271  * Dumps declarations of global variables and the initialization code.
1272  *
1273  * @param gt                a global like type, either the global or the TLS one
1274  * @param env               an environment
1275  * @param only_emit_marked  if non-zero, external allocated entities that do not have
1276  *                          its visited flag set are ignored
1277  */
1278 static void be_gas_dump_globals(ir_type *gt, be_gas_decl_env_t *env,
1279                                 int only_emit_marked)
1280 {
1281         int i, n = get_compound_n_members(gt);
1282         waitq *worklist = new_waitq();
1283
1284         if (only_emit_marked) {
1285                 for (i = 0; i < n; i++) {
1286                         ir_entity *ent = get_compound_member(gt, i);
1287                         if (is_entity_backend_marked(ent) ||
1288                             get_entity_visibility(ent) != visibility_external_allocated) {
1289                                 waitq_put(worklist, ent);
1290                                 set_entity_backend_marked(ent, 1);
1291                         }
1292                 }
1293         } else {
1294                 for (i = 0; i < n; i++) {
1295                         ir_entity *ent = get_compound_member(gt, i);
1296                         set_entity_backend_marked(ent, 1);
1297                         waitq_put(worklist, ent);
1298                 }
1299         }
1300
1301         env->worklist = worklist;
1302
1303         while (!waitq_empty(worklist)) {
1304                 ir_entity *ent = waitq_get(worklist);
1305
1306                 dump_global(env, ent);
1307         }
1308
1309         del_waitq(worklist);
1310         env->worklist = NULL;
1311 }
1312
1313 /************************************************************************/
1314
1315 /* Generate all entities. */
1316 void be_gas_emit_decls(const be_main_env_t *main_env,
1317                        int only_emit_marked_entities)
1318 {
1319         be_gas_decl_env_t env;
1320         memset(&env, 0, sizeof(env));
1321
1322         /* dump global type */
1323         env.section = (be_gas_section_t) -1;
1324         be_gas_dump_globals(get_glob_type(), &env, only_emit_marked_entities);
1325         env.section = GAS_SECTION_TLS;
1326         be_gas_dump_globals(get_tls_type(), &env, only_emit_marked_entities);
1327         env.section = GAS_SECTION_CONSTRUCTORS;
1328         be_gas_dump_globals(get_segment_type(IR_SEGMENT_CONSTRUCTORS), &env,
1329                             only_emit_marked_entities);
1330         env.section = GAS_SECTION_DESTRUCTORS;
1331         be_gas_dump_globals(get_segment_type(IR_SEGMENT_DESTRUCTORS), &env,
1332                             only_emit_marked_entities);
1333
1334         env.section = GAS_SECTION_PIC_SYMBOLS;
1335         be_gas_dump_globals(main_env->pic_symbols_type, &env,
1336                             only_emit_marked_entities);
1337
1338         if (get_compound_n_members(main_env->pic_trampolines_type) > 0) {
1339                 env.section = GAS_SECTION_PIC_TRAMPOLINES;
1340                 be_gas_dump_globals(main_env->pic_trampolines_type, &env,
1341                                     only_emit_marked_entities);
1342                 if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
1343                         be_emit_cstring("\t.subsections_via_symbols\n");
1344                         be_emit_write_line();
1345                 }
1346         }
1347 }