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[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 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30
31 #include "begnuas.h"
32
33 #include <stdlib.h>
34 #include <string.h>
35 #include <ctype.h>
36 #include <assert.h>
37
38 #include "obst.h"
39 #include "tv.h"
40 #include "irnode.h"
41 #include "irprog.h"
42 #include "pdeq.h"
43 #include "entity_t.h"
44 #include "error.h"
45
46 #include "be_t.h"
47 #include "beemitter.h"
48 #include "be_dbgout.h"
49
50 /** by default, we generate assembler code for the Linux gas */
51 be_gas_flavour_t be_gas_flavour = GAS_FLAVOUR_ELF;
52
53 static be_gas_section_t current_section = (be_gas_section_t) -1;
54
55 /**
56  * Return the pseudo-instruction to be issued for a section switch
57  * depending on the current flavour.
58  *
59  * @param section  the section to switch to
60  *
61  * @return  the pseudo-instruction
62  */
63 static const char *get_section_name(be_gas_section_t section) {
64         static const char *text[GAS_FLAVOUR_LAST+1][GAS_SECTION_LAST+1] = {
65                 { /* GAS_FLAVOUR_ELF */
66                         ".section\t.text",
67                         ".section\t.data",
68                         ".section\t.rodata",
69                         ".section\t.bss",
70                         ".section\t.tbss,\"awT\",@nobits",
71                         ".section\t.ctors,\"aw\",@progbits",
72                         ".section\t.dtors,\"aw\",@progbits",
73                         NULL, /* no cstring section */
74                         NULL,
75                         NULL
76                 },
77                 { /* GAS_FLAVOUR_MINGW */
78                         ".section\t.text",
79                         ".section\t.data",
80                         ".section .rdata,\"dr\"",
81                         ".section\t.bss",
82                         ".section\t.tbss,\"awT\",@nobits",
83                         ".section\t.ctors,\"aw\",@progbits",
84                         ".section\t.dtors,\"aw\",@progbits",
85                         NULL,
86                         NULL,
87                         NULL
88                 },
89                 { /* GAS_FLAVOUR_YASM */
90                         ".section\t.text",
91                         ".section\t.data",
92                         ".section\t.rodata",
93                         ".section\t.bss",
94                         ".section\t.tbss,\"awT\",@nobits",
95                         ".section\t.ctors,\"aw\",@progbits",
96                         ".section\t.dtors,\"aw\",@progbits",
97                         NULL,
98                         NULL,
99                         NULL
100                 },
101                 { /* GAS_FLAVOUR_MACH_O */
102                         ".text",
103                         ".data",
104                         ".const",
105                         ".data",
106                         NULL,             /* TLS is not supported on Mach-O */
107                         ".mod_init_func",
108                         NULL,             /* TODO: how is this called? */
109                         ".cstring",
110                         ".section\t__IMPORT,__jump_table,symbol_stubs,self_modifying_code+pure_instructions,5",
111                         ".section\t__IMPORT,__pointers,non_lazy_symbol_pointers"
112                 }
113         };
114
115         assert((int) be_gas_flavour >= 0 && be_gas_flavour <= GAS_FLAVOUR_LAST);
116         assert((int) section >= 0 && section <= GAS_SECTION_LAST);
117         return text[be_gas_flavour][section];
118 }
119
120 void be_gas_emit_switch_section(be_gas_section_t section) {
121         if(current_section == section)
122                 return;
123
124         be_emit_char('\t');
125         be_emit_string(get_section_name(section));
126         be_emit_char('\n');
127         be_emit_write_line();
128         current_section = section;
129 }
130
131 void be_gas_emit_function_prolog(ir_entity *entity, unsigned alignment)
132 {
133         const char *name = get_entity_ld_name(entity);
134         const char *fill_byte = "";
135         unsigned maximum_skip;
136
137         be_gas_emit_switch_section(GAS_SECTION_TEXT);
138
139         /* write the begin line (used by scripts processing the assembler... */
140         be_emit_write_line();
141         be_emit_cstring("# -- Begin  ");
142         be_emit_string(name);
143         be_emit_char('\n');
144         be_emit_write_line();
145
146         /* gcc fills space between function with 0x90, no idea if this is needed */
147         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
148                 fill_byte = "0x90";
149         }
150
151         if (alignment > 0) {
152                 maximum_skip = (1 << alignment) - 1;
153                 be_emit_cstring("\t.p2align ");
154                 be_emit_irprintf("%u,%s,%u\n", alignment, fill_byte, maximum_skip);
155                 be_emit_write_line();
156         }
157         if (get_entity_visibility(entity) == visibility_external_visible) {
158                 be_emit_cstring(".globl ");
159                 be_emit_string(name);
160                 be_emit_char('\n');
161                 be_emit_write_line();
162         }
163
164         switch (be_gas_flavour) {
165         case GAS_FLAVOUR_ELF:
166                 be_emit_cstring("\t.type\t");
167                 be_emit_string(name);
168                 be_emit_cstring(", @function\n");
169                 be_emit_write_line();
170                 break;
171         case GAS_FLAVOUR_MINGW:
172                 be_emit_cstring("\t.def\t");
173                 be_emit_string(name);
174                 if (get_entity_visibility(entity) == visibility_external_visible) {
175                         be_emit_cstring(";\t.scl\t2;\t.type\t32;\t.endef\n");
176                 } else {
177                         be_emit_cstring(";\t.scl\t3;\t.type\t32;\t.endef\n");
178                 }
179                 be_emit_write_line();
180                 break;
181         case GAS_FLAVOUR_MACH_O:
182         case GAS_FLAVOUR_YASM:
183                 break;
184         }
185         be_emit_string(name);
186         be_emit_cstring(":\n");
187         be_emit_write_line();
188 }
189
190 void be_gas_emit_function_epilog(ir_entity *entity)
191 {
192         const char *name = get_entity_ld_name(entity);
193
194         if (be_gas_flavour == GAS_FLAVOUR_ELF) {
195                 be_emit_cstring("\t.size\t");
196                 be_emit_string(name);
197                 be_emit_cstring(", .-");
198                 be_emit_string(name);
199                 be_emit_char('\n');
200                 be_emit_write_line();
201         }
202
203         be_emit_cstring("# -- End  ");
204         be_emit_string(name);
205         be_emit_char('\n');
206         be_emit_write_line();
207 }
208
209 /**
210  * An environment containing all needed dumper data.
211  * Currently we create the file completely in memory first, then
212  * write it to the disk. This is an artifact from the old C-generating backend
213  * and even there NOT needed. So we might change it in the future.
214  */
215 typedef struct _be_gas_decl_env {
216         const be_main_env_t *main_env; /**< The main backend environment, used for it's debug handle. */
217         be_gas_section_t     section;
218         waitq               *worklist;           /**< A worklist we use to place not yet handled entities on. */
219 } be_gas_decl_env_t;
220
221 /************************************************************************/
222
223 /**
224  * Output a tarval.
225  *
226  * @param tv     the tarval
227  * @param bytes  the width of the tarvals value in bytes
228  */
229 static void dump_arith_tarval(tarval *tv, int bytes)
230 {
231         switch (bytes) {
232         case 1:
233                 be_emit_irprintf("0x%02x", get_tarval_sub_bits(tv, 0));
234                 return;
235
236         case 2:
237                 be_emit_irprintf("0x%02x%02x", get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
238                 return;
239
240         case 4:
241                 be_emit_irprintf("0x%02x%02x%02x%02x",
242                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
243                 return;
244
245         case 8:
246                 be_emit_irprintf("0x%02x%02x%02x%02x%02x%02x%02x%02x",
247                         get_tarval_sub_bits(tv, 7), get_tarval_sub_bits(tv, 6), get_tarval_sub_bits(tv, 5), get_tarval_sub_bits(tv, 4),
248                         get_tarval_sub_bits(tv, 3), get_tarval_sub_bits(tv, 2), get_tarval_sub_bits(tv, 1), get_tarval_sub_bits(tv, 0));
249                 return;
250
251         case 12:
252                 /* Beware: Mixed endian output!  One little endian number emitted as
253                  * three longs.  Each long initializer is written in big endian. */
254                 be_emit_irprintf(
255                         "\t.long\t0x%02x%02x%02x%02x\n"
256                         "\t.long\t0x%02x%02x%02x%02x\n"
257                         "\t.long\t0x%02x%02x%02x%02x",
258                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
259                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0),
260                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
261                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
262                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
263                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8)
264                 );
265                 return;
266
267         case 16:
268                 be_emit_irprintf(
269                         "\t.long\t0x%02x%02x%02x%02x0x%02x%02x%02x%02x0x%02x%02x%02x%02x0x%02x%02x%02x%02x",
270                         get_tarval_sub_bits(tv, 15), get_tarval_sub_bits(tv, 16),
271                         get_tarval_sub_bits(tv, 13), get_tarval_sub_bits(tv, 12),
272                         get_tarval_sub_bits(tv, 11), get_tarval_sub_bits(tv, 10),
273                         get_tarval_sub_bits(tv,  9), get_tarval_sub_bits(tv,  8),
274                         get_tarval_sub_bits(tv,  7), get_tarval_sub_bits(tv,  6),
275                         get_tarval_sub_bits(tv,  5), get_tarval_sub_bits(tv,  4),
276                         get_tarval_sub_bits(tv,  3), get_tarval_sub_bits(tv,  2),
277                         get_tarval_sub_bits(tv,  1), get_tarval_sub_bits(tv,  0)
278                 );
279                 return;
280         }
281
282         panic("Can't dump a tarval with %d bytes", bytes);
283 }
284
285 /**
286  * Return the label prefix for labeled blocks.
287  */
288 const char *be_gas_block_label_prefix(void) {
289         return ".LG";
290 }
291
292 /**
293  * Return the label prefix for labeled instructions.
294  */
295 const char *be_gas_insn_label_prefix(void) {
296         return ".LE";
297 }
298
299 /**
300  * Dump a label.
301  */
302 static void dump_label(ir_label_t label) {
303         be_emit_irprintf("%s%lu", be_gas_block_label_prefix(), label);
304 }
305
306 /**
307  * Return the tarval of an atomic initializer.
308  *
309  * @param init  a node representing the initializer (on the const code irg)
310  *
311  * @return the tarval
312  */
313 static tarval *get_atomic_init_tv(ir_node *init)
314 {
315         for (;;) {
316                 ir_mode *mode = get_irn_mode(init);
317
318                 switch (get_irn_opcode(init)) {
319
320                 case iro_Cast:
321                         init = get_Cast_op(init);
322                         continue;
323
324                 case iro_Conv:
325                         init = get_Conv_op(init);
326                         continue;
327
328                 case iro_Const:
329                         return get_Const_tarval(init);
330
331                 case iro_SymConst:
332                         switch (get_SymConst_kind(init)) {
333                         case symconst_type_size:
334                                 return new_tarval_from_long(get_type_size_bytes(get_SymConst_type(init)), mode);
335
336                         case symconst_type_align:
337                                 return new_tarval_from_long(get_type_alignment_bytes(get_SymConst_type(init)), mode);
338
339                         case symconst_ofs_ent:
340                                 return new_tarval_from_long(get_entity_offset(get_SymConst_entity(init)), mode);
341
342                         case symconst_enum_const:
343                                 return get_enumeration_value(get_SymConst_enum(init));
344
345                         case symconst_label:
346                                 return NULL;
347
348                         default:
349                                 return NULL;
350                         }
351
352                 default:
353                         return NULL;
354                 }
355         }
356 }
357
358 /**
359  * Dump an atomic value.
360  *
361  * @param env   the gas output environment
362  * @param init  a node representing the atomic value (on the const code irg)
363  */
364 static void do_dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
365 {
366         ir_mode *mode = get_irn_mode(init);
367         int bytes     = get_mode_size_bytes(mode);
368         tarval *tv;
369         ir_label_t label;
370         ir_entity *ent;
371
372         init = skip_Id(init);
373
374         switch (get_irn_opcode(init)) {
375         case iro_Cast:
376                 do_dump_atomic_init(env, get_Cast_op(init));
377                 return;
378
379         case iro_Conv:
380                 do_dump_atomic_init(env, get_Conv_op(init));
381                 return;
382
383         case iro_Const:
384                 tv = get_Const_tarval(init);
385
386                 /* it's a arithmetic value */
387                 dump_arith_tarval(tv, bytes);
388                 return;
389
390         case iro_SymConst:
391                 switch (get_SymConst_kind(init)) {
392                 case symconst_addr_name:
393                         be_emit_ident(get_SymConst_name(init));
394                         break;
395
396                 case symconst_addr_ent:
397                         ent = get_SymConst_entity(init);
398                         if(!is_entity_backend_marked(ent)) {
399                                 waitq_put(env->worklist, ent);
400                                 set_entity_backend_marked(ent, 1);
401                         }
402                         be_emit_ident(get_entity_ld_ident(ent));
403                         break;
404
405                 case symconst_ofs_ent:
406                         ent = get_SymConst_entity(init);
407 #if 0       /* not needed, is it? */
408                         if(!is_entity_backend_marked(ent)) {
409                                 waitq_put(env->worklist, ent);
410                                 set_entity_backend_marked(ent, 1);
411                         }
412 #endif
413                         be_emit_irprintf("%d", get_entity_offset(ent));
414                         break;
415
416                 case symconst_type_size:
417                         be_emit_irprintf("%u", get_type_size_bytes(get_SymConst_type(init)));
418                         break;
419
420                 case symconst_type_align:
421                         be_emit_irprintf("%u", get_type_alignment_bytes(get_SymConst_type(init)));
422                         break;
423
424                 case symconst_enum_const:
425                         tv = get_enumeration_value(get_SymConst_enum(init));
426                         dump_arith_tarval(tv, bytes);
427                         break;
428
429                 case symconst_label:
430                         label = get_SymConst_label(init);
431                         dump_label(label);
432                         break;
433
434                 default:
435                         assert(!"dump_atomic_init(): don't know how to init from this SymConst");
436                 }
437                 return;
438
439         case iro_Add:
440                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
441                         panic("Constant must be int or pointer for '+' to work");
442                 }
443                 do_dump_atomic_init(env, get_Add_left(init));
444                 be_emit_cstring(" + ");
445                 do_dump_atomic_init(env, get_Add_right(init));
446                 return;
447
448         case iro_Sub:
449                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
450                         panic("Constant must be int or pointer for '-' to work");
451                 }
452                 do_dump_atomic_init(env, get_Sub_left(init));
453                 be_emit_cstring(" - ");
454                 do_dump_atomic_init(env, get_Sub_right(init));
455                 return;
456
457         case iro_Mul:
458                 if (!mode_is_int(mode) && !mode_is_reference(mode)) {
459                         panic("Constant must be int or pointer for '*' to work");
460                 }
461                 do_dump_atomic_init(env, get_Mul_left(init));
462                 be_emit_cstring(" * ");
463                 do_dump_atomic_init(env, get_Mul_right(init));
464                 return;
465
466         default:
467                 panic("dump_atomic_init(): unsupported IR-node %+F", init);
468         }
469 }
470
471 /**
472  * Dumps the type for given size (.byte, .long, ...)
473  *
474  * @param size  the size in bytes
475  */
476 static void dump_size_type(size_t size) {
477         switch (size) {
478         case 1:
479                 be_emit_cstring("\t.byte\t");
480                 break;
481
482         case 2:
483                 be_emit_cstring("\t.word\t");
484                 break;
485
486         case 4:
487                 be_emit_cstring("\t.long\t");
488                 break;
489
490         case 8:
491                 be_emit_cstring("\t.quad\t");
492                 break;
493
494         case 10:
495         case 12:
496                 /* handled in arith */
497                 break;
498
499         case 16:
500                 be_emit_cstring("\t.octa\t");
501                 break;
502
503         default:
504                 panic("Try to dump a type with %u bytes", (unsigned)size);
505         }
506 }
507
508 /**
509  * Emit an atomic value.
510  *
511  * @param env   the gas output environment
512  * @param init  a node representing the atomic value (on the const code irg)
513  */
514 static void dump_atomic_init(be_gas_decl_env_t *env, ir_node *init)
515 {
516         ir_mode *mode = get_irn_mode(init);
517         int bytes     = get_mode_size_bytes(mode);
518
519         dump_size_type(bytes);
520         do_dump_atomic_init(env, init);
521         be_emit_char('\n');
522         be_emit_write_line();
523 }
524
525 /************************************************************************/
526 /* Routines to dump global variables                                    */
527 /************************************************************************/
528
529 static int initializer_is_string_const(const ir_initializer_t *initializer)
530 {
531         size_t i, len;
532         int found_printable = 0;
533
534         if(initializer->kind != IR_INITIALIZER_COMPOUND)
535                 return 0;
536
537         len = initializer->compound.n_initializers;
538         if (len < 1)
539                 return 0;
540         for(i = 0; i < len; ++i) {
541                 int               c;
542                 tarval           *tv;
543                 ir_mode          *mode;
544                 ir_initializer_t *sub_initializer
545                         = initializer->compound.initializers[i];
546
547                 if(sub_initializer->kind != IR_INITIALIZER_TARVAL)
548                         return 0;
549
550                 tv   = sub_initializer->tarval.value;
551                 mode = get_tarval_mode(tv);
552
553                 if (!mode_is_int(mode)
554                                 || get_mode_size_bits(mode) != get_mode_size_bits(mode_Bs))
555                         return 0;
556
557                 c = get_tarval_long(tv);
558                 if (isgraph(c) || isspace(c))
559                         found_printable = 1;
560                 else if(c != 0)
561                         return 0;
562
563                 if (i == len - 1 && c != '\0')
564                         return 0;
565         }
566
567         return found_printable;
568 }
569
570 /**
571  * Determine if an entity is a string constant
572  * @param ent The entity
573  * @return 1 if it is a string constant, 0 otherwise
574  */
575 static int ent_is_string_const(ir_entity *ent)
576 {
577         ir_type *type, *element_type;
578         ir_mode *mode;
579         int i, c, n;
580         int found_printable = 0;
581
582         type = get_entity_type(ent);
583
584         /* if it's an array */
585         if (!is_Array_type(type))
586                 return 0;
587
588         element_type = get_array_element_type(type);
589
590         /* and the array's element type is primitive */
591         if (!is_Primitive_type(element_type))
592                 return 0;
593
594         /* and the mode of the element type is an int of
595          * the same size as the byte mode */
596         mode = get_type_mode(element_type);
597         if (!mode_is_int(mode)
598                 || get_mode_size_bits(mode) != get_mode_size_bits(mode_Bs))
599                 return 0;
600
601         if(ent->has_initializer) {
602                 /* TODO */
603                 return 0;
604         } else {
605                 /* if it contains only printable chars and a 0 at the end */
606                 n = get_compound_ent_n_values(ent);
607                 for (i = 0; i < n; ++i) {
608                         ir_node *irn = get_compound_ent_value(ent, i);
609                         if (! is_Const(irn))
610                                 return 0;
611
612                         c = (int) get_tarval_long(get_Const_tarval(irn));
613
614                         if (isgraph(c) || isspace(c))
615                                 found_printable = 1;
616                         else if(c != 0)
617                                 return 0;
618
619                         if (i == n - 1 && c != '\0')
620                                 return 0;
621                 }
622         }
623
624         /* then we can emit it as a string constant */
625         return found_printable;
626 }
627
628 /**
629  * Dump a string constant.
630  * No checks are made!!
631  *
632  * @param ent  The entity to dump.
633  */
634 static void dump_string_cst(ir_entity *ent)
635 {
636         int      i, len;
637         int      output_len;
638         ir_type *type;
639         int      type_size;
640         int      remaining_space;
641
642         len        = get_compound_ent_n_values(ent);
643         output_len = len;
644         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
645                 be_emit_cstring("\t.ascii \"");
646         } else {
647                 be_emit_cstring("\t.string \"");
648                 output_len -= 1;
649         }
650
651         for (i = 0; i < output_len; ++i) {
652                 ir_node *irn;
653                 int c;
654
655                 irn = get_compound_ent_value(ent, i);
656                 c = (int) get_tarval_long(get_Const_tarval(irn));
657
658                 switch (c) {
659                 case '"' : be_emit_cstring("\\\""); break;
660                 case '\n': be_emit_cstring("\\n"); break;
661                 case '\r': be_emit_cstring("\\r"); break;
662                 case '\t': be_emit_cstring("\\t"); break;
663                 case '\\': be_emit_cstring("\\\\"); break;
664                 default  :
665                         if (isprint(c))
666                                 be_emit_char(c);
667                         else
668                                 be_emit_irprintf("\\%o", c);
669                         break;
670                 }
671         }
672         be_emit_cstring("\"\n");
673         be_emit_write_line();
674
675         type            = get_entity_type(ent);
676         type_size       = get_type_size_bytes(type);
677         remaining_space = type_size - len;
678         assert(remaining_space >= 0);
679         if(remaining_space > 0) {
680                 be_emit_irprintf("\t.space\t%d\n", remaining_space);
681         }
682 }
683
684 static void dump_string_initializer(const ir_initializer_t *initializer)
685 {
686         size_t i, len;
687
688         len = initializer->compound.n_initializers;
689         if(be_gas_flavour == GAS_FLAVOUR_MACH_O) {
690                 be_emit_cstring("\t.ascii \"");
691         } else {
692                 be_emit_cstring("\t.string \"");
693                 len -= 1;
694         }
695
696         for(i = 0; i < len; ++i) {
697                 const ir_initializer_t *sub_initializer
698                         = get_initializer_compound_value(initializer, i);
699
700                 tarval *tv = get_initializer_tarval_value(sub_initializer);
701                 int     c  = get_tarval_long(tv);
702
703                 switch (c) {
704                 case '"' : be_emit_cstring("\\\""); break;
705                 case '\n': be_emit_cstring("\\n"); break;
706                 case '\r': be_emit_cstring("\\r"); break;
707                 case '\t': be_emit_cstring("\\t"); break;
708                 case '\\': be_emit_cstring("\\\\"); break;
709                 default  :
710                         if (isprint(c))
711                                 be_emit_char(c);
712                         else
713                                 be_emit_irprintf("\\%o", c);
714                         break;
715                 }
716         }
717         be_emit_cstring("\"\n");
718         be_emit_write_line();
719 }
720
721 enum normal_or_bitfield_kind {
722         NORMAL = 0,
723         TARVAL,
724         BITFIELD
725 };
726
727 typedef struct {
728         enum normal_or_bitfield_kind kind;
729         union {
730                 ir_node       *value;
731                 tarval        *tarval;
732                 unsigned char  bf_val;
733         } v;
734 } normal_or_bitfield;
735
736 static int is_type_variable_size(ir_type *type)
737 {
738         (void) type;
739         /* TODO */
740         return 0;
741 }
742
743 static size_t get_initializer_size(const ir_initializer_t *initializer,
744                                    ir_type *type)
745 {
746         switch(get_initializer_kind(initializer)) {
747         case IR_INITIALIZER_TARVAL: {
748                 assert(get_tarval_mode(get_initializer_tarval_value(initializer)) == get_type_mode(type));
749                 return get_type_size_bytes(type);
750         }
751         case IR_INITIALIZER_CONST:
752         case IR_INITIALIZER_NULL:
753                 return get_type_size_bytes(type);
754         case IR_INITIALIZER_COMPOUND: {
755                 if(!is_type_variable_size(type)) {
756                         return get_type_size_bytes(type);
757                 } else {
758                         unsigned n_entries
759                                 = get_initializer_compound_n_entries(initializer);
760                         unsigned i;
761                         unsigned initializer_size = get_type_size_bytes(type);
762                         for(i = 0; i < n_entries; ++i) {
763                                 ir_entity *entity = get_compound_member(type, i);
764                                 ir_type   *type   = get_entity_type(entity);
765
766                                 const ir_initializer_t *sub_initializer
767                                         = get_initializer_compound_value(initializer, i);
768
769                                 unsigned offset = get_entity_offset(entity);
770                                 unsigned size   = get_initializer_size(sub_initializer, type);
771
772                                 if(offset + size > initializer_size) {
773                                         initializer_size = offset + size;
774                                 }
775                         }
776                         return initializer_size;
777                 }
778         }
779         }
780
781         panic("found invalid initializer");
782 }
783
784 #ifndef NDEBUG
785 static normal_or_bitfield *glob_vals;
786 static size_t              max_vals;
787 #endif
788
789 static void dump_bitfield(normal_or_bitfield *vals, size_t offset_bits,
790                           const ir_initializer_t *initializer, ir_type *type)
791 {
792         unsigned char  last_bits = 0;
793         ir_mode       *mode      = get_type_mode(type);
794         tarval        *tv        = NULL;
795         unsigned char  curr_bits;
796         int            value_len;
797         int            j;
798
799         switch(get_initializer_kind(initializer)) {
800         case IR_INITIALIZER_NULL:
801                 return;
802         case IR_INITIALIZER_TARVAL:
803                 tv = get_initializer_tarval_value(initializer);
804                 break;
805         case IR_INITIALIZER_CONST: {
806                 ir_node *node = get_initializer_const_value(initializer);
807                 if(!is_Const(node)) {
808                         panic("bitfield initializer not a Const node");
809                 }
810                 tv = get_Const_tarval(node);
811                 break;
812         }
813         case IR_INITIALIZER_COMPOUND:
814                 panic("bitfield initializer is compound");
815         }
816         if (tv == NULL) {
817                 panic("Couldn't get numeric value for bitfield initializer");
818         }
819         tv = tarval_convert_to(tv, get_type_mode(type));
820
821         /* normalize offset */
822         vals        += offset_bits >> 3;
823         offset_bits &= 7;
824         value_len    = get_mode_size_bits(mode);
825
826         /* combine bits with existing bits */
827         for (j = 0; value_len + (int) offset_bits > 0; ++j) {
828                 assert((size_t) (vals - glob_vals) + j < max_vals);
829                 assert(vals[j].kind == BITFIELD ||
830                                 (vals[j].kind == NORMAL && vals[j].v.value == NULL));
831                 vals[j].kind = BITFIELD;
832                 curr_bits    = get_tarval_sub_bits(tv, j);
833                 vals[j].v.bf_val
834                         |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
835                 value_len -= 8;
836                 last_bits = curr_bits;
837         }
838 }
839
840 static void dump_ir_initializer(normal_or_bitfield *vals,
841                                 const ir_initializer_t *initializer,
842                                 ir_type *type)
843 {
844         assert((size_t) (vals - glob_vals) < max_vals);
845
846         switch(get_initializer_kind(initializer)) {
847         case IR_INITIALIZER_NULL:
848                 return;
849         case IR_INITIALIZER_TARVAL: {
850                 size_t i;
851
852                 assert(vals->kind != BITFIELD);
853                 vals->kind     = TARVAL;
854                 vals->v.tarval = get_initializer_tarval_value(initializer);
855                 assert(get_type_mode(type) == get_tarval_mode(vals->v.tarval));
856                 for(i = 1; i < get_type_size_bytes(type); ++i) {
857                         vals[i].kind    = NORMAL;
858                         vals[i].v.value = NULL;
859                 }
860                 return;
861         }
862         case IR_INITIALIZER_CONST: {
863                 size_t i;
864
865                 assert(vals->kind != BITFIELD);
866                 vals->kind    = NORMAL;
867                 vals->v.value = get_initializer_const_value(initializer);
868                 for(i = 1; i < get_type_size_bytes(type); ++i) {
869                         vals[i].kind    = NORMAL;
870                         vals[i].v.value = NULL;
871                 }
872                 return;
873         }
874         case IR_INITIALIZER_COMPOUND: {
875                 size_t i = 0;
876                 size_t n = get_initializer_compound_n_entries(initializer);
877
878                 if(is_Array_type(type)) {
879                         ir_type *element_type = get_array_element_type(type);
880                         size_t   skip         = get_type_size_bytes(element_type);
881                         size_t   alignment    = get_type_alignment_bytes(element_type);
882                         size_t   misalign     = skip % alignment;
883                         if(misalign != 0) {
884                                 skip += alignment - misalign;
885                         }
886
887                         for(i = 0; i < n; ++i) {
888                                 ir_initializer_t *sub_initializer
889                                         = get_initializer_compound_value(initializer, i);
890
891                                 dump_ir_initializer(vals, sub_initializer, element_type);
892
893                                 vals += skip;
894                         }
895                 } else {
896                         size_t n_members, i;
897                         assert(is_compound_type(type));
898                         n_members = get_compound_n_members(type);
899                         for(i = 0; i < n_members; ++i) {
900                                 ir_entity        *member    = get_compound_member(type, i);
901                                 size_t            offset    = get_entity_offset(member);
902                                 ir_type          *subtype   = get_entity_type(member);
903                                 ir_mode          *mode      = get_type_mode(subtype);
904                                 ir_initializer_t *sub_initializer;
905
906                                 assert(i < get_initializer_compound_n_entries(initializer));
907                                 sub_initializer
908                                         = get_initializer_compound_value(initializer, i);
909
910                                 if(mode != NULL) {
911                                         size_t offset_bits
912                                                 = get_entity_offset_bits_remainder(member);
913                                         size_t value_len   = get_mode_size_bits(mode);
914
915                                         if(offset_bits != 0 ||
916                                                 (value_len != 8 && value_len != 16 && value_len != 32
917                                                  && value_len != 64)) {
918                                                 dump_bitfield(&vals[offset], offset_bits,
919                                                               sub_initializer, subtype);
920                                                 continue;
921                                         }
922                                 }
923
924                                 dump_ir_initializer(&vals[offset], sub_initializer, subtype);
925                         }
926                 }
927
928                 return;
929         }
930         }
931         panic("invalid ir_initializer kind found");
932 }
933
934 static void dump_initializer(be_gas_decl_env_t *env, ir_entity *entity)
935 {
936         const ir_initializer_t *initializer = entity->attr.initializer;
937         ir_type                *type;
938         normal_or_bitfield     *vals;
939         size_t                  size;
940         size_t                  k;
941
942         if(initializer_is_string_const(initializer)) {
943                 dump_string_initializer(initializer);
944                 return;
945         }
946
947         type = get_entity_type(entity);
948         size = get_initializer_size(initializer, type);
949
950         if (size == 0)
951                 return;
952
953         /*
954          * In the worst case, every initializer allocates one byte.
955          * Moreover, initializer might be big, do not allocate on stack.
956          */
957         vals = XMALLOCNZ(normal_or_bitfield, size);
958
959 #ifndef NDEBUG
960         glob_vals = vals;
961         max_vals  = size;
962 #endif
963
964         dump_ir_initializer(vals, initializer, type);
965
966         /* now write values sorted */
967         for (k = 0; k < size; ) {
968                 int space     = 0;
969                 int elem_size = 1;
970                 if (vals[k].kind == NORMAL) {
971                         if(vals[k].v.value != NULL) {
972                                 dump_atomic_init(env, vals[k].v.value);
973                                 elem_size = get_mode_size_bytes(get_irn_mode(vals[k].v.value));
974                         } else {
975                                 elem_size = 0;
976                         }
977                 } else if(vals[k].kind == TARVAL) {
978                         tarval *tv   = vals[k].v.tarval;
979                         size_t  size = get_mode_size_bytes(get_tarval_mode(tv));
980
981                         assert(tv != NULL);
982
983                         elem_size = size;
984                         dump_size_type(size);
985                         dump_arith_tarval(tv, size);
986                         be_emit_char('\n');
987                         be_emit_write_line();
988                 } else {
989                         assert(vals[k].kind == BITFIELD);
990                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
991                         be_emit_write_line();
992                 }
993
994                 k += elem_size;
995                 while (k < size && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
996                         ++space;
997                         ++k;
998                 }
999
1000                 /* a gap */
1001                 if (space > 0) {
1002                         be_emit_irprintf("\t.space\t%d\n", space);
1003                         be_emit_write_line();
1004                 }
1005         }
1006         xfree(vals);
1007 }
1008
1009 /**
1010  * Dump an initializer for a compound entity.
1011  */
1012 static void dump_compound_init(be_gas_decl_env_t *env, ir_entity *ent)
1013 {
1014         normal_or_bitfield *vals;
1015         int i, j, n;
1016         unsigned k, last_ofs;
1017
1018         if(ent->has_initializer) {
1019                 dump_initializer(env, ent);
1020                 return;
1021         }
1022
1023         n = get_compound_ent_n_values(ent);
1024
1025         /* Find the initializer size. Sorrily gcc support a nasty feature:
1026            The last field of a compound may be a flexible array. This allows
1027            initializers bigger than the type size. */
1028         last_ofs = get_type_size_bytes(get_entity_type(ent));
1029         for (i = 0; i < n; ++i) {
1030                 unsigned offset         = get_compound_ent_value_offset_bytes(ent, i);
1031                 unsigned bits_remainder = get_compound_ent_value_offset_bit_remainder(ent, i);
1032                 ir_node  *value         = get_compound_ent_value(ent, i);
1033                 unsigned value_len      = get_mode_size_bits(get_irn_mode(value));
1034
1035                 offset += (value_len + bits_remainder + 7) >> 3;
1036
1037                 if (offset > last_ofs) {
1038                         last_ofs = offset;
1039                 }
1040         }
1041
1042         /*
1043          * In the worst case, every initializer allocates one byte.
1044          * Moreover, initializer might be big, do not allocate on stack.
1045          */
1046         vals = XMALLOCNZ(normal_or_bitfield, last_ofs);
1047
1048         /* collect the values and store them at the offsets */
1049         for (i = 0; i < n; ++i) {
1050                 unsigned offset      = get_compound_ent_value_offset_bytes(ent, i);
1051                 int      offset_bits = get_compound_ent_value_offset_bit_remainder(ent, i);
1052                 ir_node  *value      = get_compound_ent_value(ent, i);
1053                 int      value_len   = get_mode_size_bits(get_irn_mode(value));
1054
1055                 assert(offset_bits >= 0);
1056
1057                 if (offset_bits != 0 ||
1058                         (value_len != 8 && value_len != 16 && value_len != 32 && value_len != 64)) {
1059                         tarval *tv = get_atomic_init_tv(value);
1060                         unsigned char curr_bits, last_bits = 0;
1061                         if (tv == NULL) {
1062                                 panic("Couldn't get numeric value for bitfield initializer '%s'",
1063                                       get_entity_ld_name(ent));
1064                         }
1065                         /* normalize offset */
1066                         offset += offset_bits >> 3;
1067                         offset_bits &= 7;
1068
1069                         for (j = 0; value_len + offset_bits > 0; ++j) {
1070                                 assert(offset + j < last_ofs);
1071                                 assert(vals[offset + j].kind == BITFIELD || vals[offset + j].v.value == NULL);
1072                                 vals[offset + j].kind = BITFIELD;
1073                                 curr_bits = get_tarval_sub_bits(tv, j);
1074                                 vals[offset + j].v.bf_val |= (last_bits >> (8 - offset_bits)) | (curr_bits << offset_bits);
1075                                 value_len -= 8;
1076                                 last_bits = curr_bits;
1077                         }
1078                 } else {
1079                         int i;
1080
1081                         assert(offset < last_ofs);
1082                         assert(vals[offset].kind == NORMAL);
1083                         for (i = 1; i < value_len / 8; ++i) {
1084                                 assert(vals[offset + i].v.value == NULL);
1085                         }
1086                         vals[offset].v.value = value;
1087                 }
1088         }
1089
1090         /* now write them sorted */
1091         for (k = 0; k < last_ofs; ) {
1092                 int space = 0, skip = 0;
1093                 if (vals[k].kind == NORMAL) {
1094                         if(vals[k].v.value != NULL) {
1095                                 dump_atomic_init(env, vals[k].v.value);
1096                                 skip = get_mode_size_bytes(get_irn_mode(vals[k].v.value)) - 1;
1097                         } else {
1098                                 space = 1;
1099                         }
1100                 } else {
1101                         assert(vals[k].kind == BITFIELD);
1102                         be_emit_irprintf("\t.byte\t%d\n", vals[k].v.bf_val);
1103                 }
1104
1105                 ++k;
1106                 while (k < last_ofs && vals[k].kind == NORMAL && vals[k].v.value == NULL) {
1107                         ++space;
1108                         ++k;
1109                 }
1110                 space -= skip;
1111                 assert(space >= 0);
1112
1113                 /* a gap */
1114                 if (space > 0) {
1115                         be_emit_irprintf("\t.space\t%d\n", space);
1116                         be_emit_write_line();
1117                 }
1118         }
1119         xfree(vals);
1120 }
1121
1122 static void emit_align(unsigned alignment)
1123 {
1124         if (!is_po2(alignment))
1125                 panic("alignment not a power of 2");
1126
1127         be_emit_irprintf("\t.p2align\t%u\n", log2_floor(alignment));
1128         be_emit_write_line();
1129 }
1130
1131 /**
1132  * Dump a global entity.
1133  *
1134  * @param env           the gas output environment
1135  * @param ent           the entity to be dumped
1136  */
1137 static void dump_global(be_gas_decl_env_t *env, ir_entity *ent)
1138 {
1139         ir_type          *type           = get_entity_type(ent);
1140         ident            *ld_ident       = get_entity_ld_ident(ent);
1141         unsigned          align          = get_type_alignment_bytes(type);
1142         int               emit_as_common = 0;
1143         be_gas_section_t  section        = env->section;
1144         ir_variability    variability    = get_entity_variability(ent);
1145         ir_visibility     visibility     = get_entity_visibility(ent);
1146
1147         if (is_Method_type(type) && section != GAS_SECTION_PIC_TRAMPOLINES) {
1148                 return;
1149         }
1150
1151         if (section != (be_gas_section_t) -1) {
1152                 emit_as_common = 0;
1153         } else if (variability == variability_constant) {
1154                 /* a constant entity, put it on the rdata */
1155                 section = GAS_SECTION_RODATA;
1156                 if (be_gas_flavour == GAS_FLAVOUR_MACH_O
1157                                 && ent_is_string_const(ent)) {
1158                         section = GAS_SECTION_CSTRING;
1159                 }
1160         } else if (variability == variability_uninitialized) {
1161                 /* uninitialized entity put it in bss segment */
1162                 section = GAS_SECTION_COMMON;
1163                 if (visibility != visibility_local)
1164                         emit_as_common = 1;
1165         } else {
1166                 section = GAS_SECTION_DATA;
1167         }
1168
1169         if(!emit_as_common) {
1170                 be_gas_emit_switch_section(section);
1171         }
1172
1173         be_dbg_variable(ent);
1174
1175         /* global or not global */
1176         if (visibility == visibility_external_visible && !emit_as_common) {
1177                 be_emit_cstring(".globl\t");
1178                 be_emit_ident(ld_ident);
1179                 be_emit_char('\n');
1180                 be_emit_write_line();
1181         } else if(visibility == visibility_external_allocated) {
1182                 be_emit_cstring(".globl\t");
1183                 be_emit_ident(ld_ident);
1184                 be_emit_char('\n');
1185                 be_emit_write_line();
1186                 /* we can return now... */
1187                 return;
1188         }
1189         /* alignment */
1190         if (align > 1 && !emit_as_common && section != GAS_SECTION_PIC_TRAMPOLINES
1191                         && section != GAS_SECTION_PIC_SYMBOLS) {
1192                 emit_align(align);
1193         }
1194
1195         if (visibility != visibility_external_allocated && !emit_as_common
1196                         && be_gas_flavour == GAS_FLAVOUR_ELF) {
1197                 be_emit_cstring("\t.type\t");
1198                 be_emit_ident(ld_ident);
1199                 be_emit_cstring(", @object\n\t.size\t");
1200                 be_emit_ident(ld_ident);
1201                 be_emit_irprintf(", %u\n", get_type_size_bytes(type));
1202         }
1203
1204         if (!emit_as_common) {
1205                 be_emit_ident(ld_ident);
1206                 be_emit_cstring(":\n");
1207                 be_emit_write_line();
1208         }
1209
1210         if (variability == variability_uninitialized) {
1211                 if (emit_as_common) {
1212                         switch (be_gas_flavour) {
1213                         case GAS_FLAVOUR_ELF:
1214                         case GAS_FLAVOUR_MACH_O:
1215                         case GAS_FLAVOUR_YASM:
1216                                 be_emit_irprintf("\t.comm %s,%u,%u\n",
1217                                         get_id_str(ld_ident), get_type_size_bytes(type), align);
1218                                 be_emit_write_line();
1219                                 break;
1220                         case GAS_FLAVOUR_MINGW:
1221                                 be_emit_irprintf("\t.comm %s,%u # %u\n",
1222                                         get_id_str(ld_ident), get_type_size_bytes(type), align);
1223                                 be_emit_write_line();
1224                                 break;
1225                         }
1226                 } else if (section == GAS_SECTION_PIC_TRAMPOLINES
1227                                 || section == GAS_SECTION_PIC_SYMBOLS) {
1228                         if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
1229                                 be_emit_cstring("\t.indirect_symbol ");
1230                                 be_emit_ident(get_entity_ident(ent));
1231                                 be_emit_char('\n');
1232                                 be_emit_write_line();
1233                                 if (section == GAS_SECTION_PIC_TRAMPOLINES) {
1234                                         be_emit_cstring("\thlt ; hlt ; hlt ; hlt ; hlt\n");
1235                                         be_emit_write_line();
1236                                 } else {
1237                                         assert(section == GAS_SECTION_PIC_SYMBOLS);
1238                                         be_emit_cstring("\t.long 0\n");
1239                                         be_emit_write_line();
1240                                 }
1241                         } else {
1242                                 panic("PIC trampolines not yet supported in this gas mode");
1243                         }
1244                 } else {
1245                         be_emit_irprintf("\t.space %u\n", get_type_size_bytes(type));
1246                         be_emit_write_line();
1247                 }
1248         } else {
1249                 if (is_atomic_entity(ent)) {
1250                         dump_atomic_init(env, get_atomic_ent_value(ent));
1251                 } else {
1252                         /* sort_compound_ent_values(ent); */
1253
1254                         switch (get_type_tpop_code(get_entity_type(ent))) {
1255                         case tpo_array:
1256                                 if (ent_is_string_const(ent))
1257                                         dump_string_cst(ent);
1258                                 else
1259                                         dump_compound_init(env, ent);
1260                                 break;
1261                         case tpo_struct:
1262                         case tpo_class:
1263                         case tpo_union:
1264                                 dump_compound_init(env, ent);
1265                                 break;
1266                         default:
1267                                 panic("Unimplemented type kind in dump_global()");
1268                         }
1269                 }
1270         }
1271 }
1272
1273 /**
1274  * Dumps declarations of global variables and the initialization code.
1275  *
1276  * @param gt                a global like type, either the global or the TLS one
1277  * @param env               an environment
1278  * @param only_emit_marked  if non-zero, external allocated entities that do not have
1279  *                          its visited flag set are ignored
1280  */
1281 static void be_gas_dump_globals(ir_type *gt, be_gas_decl_env_t *env,
1282                                 int only_emit_marked)
1283 {
1284         int i, n = get_compound_n_members(gt);
1285         waitq *worklist = new_waitq();
1286
1287         if (only_emit_marked) {
1288                 for (i = 0; i < n; i++) {
1289                         ir_entity *ent = get_compound_member(gt, i);
1290                         if (is_entity_backend_marked(ent) ||
1291                             get_entity_visibility(ent) != visibility_external_allocated) {
1292                                 waitq_put(worklist, ent);
1293                                 set_entity_backend_marked(ent, 1);
1294                         }
1295                 }
1296         } else {
1297                 for (i = 0; i < n; i++) {
1298                         ir_entity *ent = get_compound_member(gt, i);
1299                         set_entity_backend_marked(ent, 1);
1300                         waitq_put(worklist, ent);
1301                 }
1302         }
1303
1304         env->worklist = worklist;
1305
1306         while (!waitq_empty(worklist)) {
1307                 ir_entity *ent = waitq_get(worklist);
1308
1309                 dump_global(env, ent);
1310         }
1311
1312         del_waitq(worklist);
1313         env->worklist = NULL;
1314 }
1315
1316 /************************************************************************/
1317
1318 /* Generate all entities. */
1319 void be_gas_emit_decls(const be_main_env_t *main_env,
1320                        int only_emit_marked_entities)
1321 {
1322         be_gas_decl_env_t env;
1323         memset(&env, 0, sizeof(env));
1324
1325         env.main_env = main_env;
1326
1327         /* dump global type */
1328         env.section = (be_gas_section_t) -1;
1329         be_gas_dump_globals(get_glob_type(), &env, only_emit_marked_entities);
1330         env.section = GAS_SECTION_TLS;
1331         be_gas_dump_globals(get_tls_type(), &env, only_emit_marked_entities);
1332         env.section = GAS_SECTION_CONSTRUCTORS;
1333         be_gas_dump_globals(get_segment_type(IR_SEGMENT_CONSTRUCTORS), &env,
1334                             only_emit_marked_entities);
1335         env.section = GAS_SECTION_DESTRUCTORS;
1336         be_gas_dump_globals(get_segment_type(IR_SEGMENT_DESTRUCTORS), &env,
1337                             only_emit_marked_entities);
1338
1339         env.section = GAS_SECTION_PIC_SYMBOLS;
1340         be_gas_dump_globals(main_env->pic_symbols_type, &env,
1341                             only_emit_marked_entities);
1342
1343         if (get_compound_n_members(main_env->pic_trampolines_type) > 0) {
1344                 env.section = GAS_SECTION_PIC_TRAMPOLINES;
1345                 be_gas_dump_globals(main_env->pic_trampolines_type, &env,
1346                                     only_emit_marked_entities);
1347                 if (be_gas_flavour == GAS_FLAVOUR_MACH_O) {
1348                         be_emit_cstring("\t.subsections_via_symbols\n");
1349                         be_emit_write_line();
1350                 }
1351         }
1352 }