1 /* yyscript.y -- linker script grammar for gold.  */
2 
3 /* Copyright (C) 2006-2014 Free Software Foundation, Inc.
4    Written by Ian Lance Taylor <iant@google.com>.
5 
6    This file is part of gold.
7 
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3 of the License, or
11    (at your option) any later version.
12 
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program; if not, write to the Free Software
20    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21    MA 02110-1301, USA.  */
22 
23 /* This is a bison grammar to parse a subset of the original GNU ld
24    linker script language.  */
25 
26 %{
27 
28 #include "config.h"
29 
30 #include <stddef.h>
31 #include <stdint.h>
32 #include <stdlib.h>
33 #include <string.h>
34 
35 #include "script-c.h"
36 
37 %}
38 
39 /* We need to use a pure parser because we might be multi-threaded.
40    We pass some arguments through the parser to the lexer.  */
41 
42 %pure-parser
43 
44 %parse-param {void* closure}
45 %lex-param {void* closure}
46 
47 /* Since we require bison anyhow, we take advantage of it.  */
48 
49 %error-verbose
50 
51 /* The values associated with tokens.  */
52 
53 %union {
54   /* A string.  */
55   struct Parser_string string;
56   /* A number.  */
57   uint64_t integer;
58   /* An expression.  */
59   Expression_ptr expr;
60   /* An output section header.  */
61   struct Parser_output_section_header output_section_header;
62   /* An output section trailer.  */
63   struct Parser_output_section_trailer output_section_trailer;
64   /* A section constraint.  */
65   enum Section_constraint constraint;
66   /* A complete input section specification.  */
67   struct Input_section_spec input_section_spec;
68   /* A list of wildcard specifications, with exclusions.  */
69   struct Wildcard_sections wildcard_sections;
70   /* A single wildcard specification.  */
71   struct Wildcard_section wildcard_section;
72   /* A list of strings.  */
73   String_list_ptr string_list;
74   /* Information for a program header.  */
75   struct Phdr_info phdr_info;
76   /* Used for version scripts and within VERSION {}.  */
77   struct Version_dependency_list* deplist;
78   struct Version_expression_list* versyms;
79   struct Version_tree* versnode;
80   enum Script_section_type section_type;
81 }
82 
83 /* Operators, including a precedence table for expressions.  */
84 
85 %right PLUSEQ MINUSEQ MULTEQ DIVEQ '=' LSHIFTEQ RSHIFTEQ ANDEQ OREQ
86 %right '?' ':'
87 %left OROR
88 %left ANDAND
89 %left '|'
90 %left '^'
91 %left '&'
92 %left EQ NE
93 %left '<' '>' LE GE
94 %left LSHIFT RSHIFT
95 %left '+' '-'
96 %left '*' '/' '%'
97 
98 /* A fake operator used to indicate unary operator precedence.  */
99 %right UNARY
100 
101 /* Constants.  */
102 
103 %token <string> STRING
104 %token <string> QUOTED_STRING
105 %token <integer> INTEGER
106 
107 /* Keywords.  This list is taken from ldgram.y and ldlex.l in the old
108    GNU linker, with the keywords which only appear in MRI mode
109    removed.  Not all these keywords are actually used in this grammar.
110    In most cases the keyword is recognized as the token name in upper
111    case.  The comments indicate where this is not the case.  */
112 
113 %token ABSOLUTE
114 %token ADDR
115 %token ALIGN_K		/* ALIGN */
116 %token ALIGNOF
117 %token ASSERT_K		/* ASSERT */
118 %token AS_NEEDED
119 %token AT
120 %token BIND
121 %token BLOCK
122 %token BYTE
123 %token CONSTANT
124 %token CONSTRUCTORS
125 %token COPY
126 %token CREATE_OBJECT_SYMBOLS
127 %token DATA_SEGMENT_ALIGN
128 %token DATA_SEGMENT_END
129 %token DATA_SEGMENT_RELRO_END
130 %token DEFINED
131 %token DSECT
132 %token ENTRY
133 %token EXCLUDE_FILE
134 %token EXTERN
135 %token FILL
136 %token FLOAT
137 %token FORCE_COMMON_ALLOCATION
138 %token GLOBAL		/* global */
139 %token GROUP
140 %token HLL
141 %token INCLUDE
142 %token INHIBIT_COMMON_ALLOCATION
143 %token INFO
144 %token INPUT
145 %token KEEP
146 %token LEN
147 %token LENGTH		/* LENGTH, l, len */
148 %token LOADADDR
149 %token LOCAL		/* local */
150 %token LONG
151 %token MAP
152 %token MAX_K		/* MAX */
153 %token MEMORY
154 %token MIN_K		/* MIN */
155 %token NEXT
156 %token NOCROSSREFS
157 %token NOFLOAT
158 %token NOLOAD
159 %token ONLY_IF_RO
160 %token ONLY_IF_RW
161 %token ORG
162 %token ORIGIN		/* ORIGIN, o, org */
163 %token OUTPUT
164 %token OUTPUT_ARCH
165 %token OUTPUT_FORMAT
166 %token OVERLAY
167 %token PHDRS
168 %token PROVIDE
169 %token PROVIDE_HIDDEN
170 %token QUAD
171 %token SEARCH_DIR
172 %token SECTIONS
173 %token SEGMENT_START
174 %token SHORT
175 %token SIZEOF
176 %token SIZEOF_HEADERS	/* SIZEOF_HEADERS, sizeof_headers */
177 %token SORT_BY_ALIGNMENT
178 %token SORT_BY_NAME
179 %token SPECIAL
180 %token SQUAD
181 %token STARTUP
182 %token SUBALIGN
183 %token SYSLIB
184 %token TARGET_K		/* TARGET */
185 %token TRUNCATE
186 %token VERSIONK		/* VERSION */
187 
188 /* Keywords, part 2.  These are keywords that are unique to gold,
189    and not present in the old GNU linker.  As before, unless the
190    comments say otherwise, the keyword is recognized as the token
191    name in upper case. */
192 
193 %token OPTION
194 
195 /* Special tokens used to tell the grammar what type of tokens we are
196    parsing.  The token stream always begins with one of these tokens.
197    We do this because version scripts can appear embedded within
198    linker scripts, and because --defsym uses the expression
199    parser.  */
200 %token PARSING_LINKER_SCRIPT
201 %token PARSING_VERSION_SCRIPT
202 %token PARSING_DEFSYM
203 %token PARSING_DYNAMIC_LIST
204 %token PARSING_SECTIONS_BLOCK
205 %token PARSING_SECTION_COMMANDS
206 %token PARSING_MEMORY_DEF
207 
208 /* Non-terminal types, where needed.  */
209 
210 %type <expr> parse_exp exp
211 %type <expr> opt_at opt_align opt_subalign opt_fill
212 %type <output_section_header> section_header opt_address_and_section_type
213 %type <section_type> section_type
214 %type <output_section_trailer> section_trailer
215 %type <constraint> opt_constraint
216 %type <string_list> opt_phdr
217 %type <integer> data_length
218 %type <input_section_spec> input_section_no_keep
219 %type <wildcard_sections> wildcard_sections
220 %type <wildcard_section> wildcard_file wildcard_section
221 %type <string_list> exclude_names
222 %type <string> wildcard_name
223 %type <integer> phdr_type memory_attr
224 %type <phdr_info> phdr_info
225 %type <versyms> vers_defns
226 %type <versnode> vers_tag
227 %type <deplist> verdep
228 %type <string> string
229 
230 %%
231 
232 /* Read the special token to see what to read next.  */
233 top:
234 	  PARSING_LINKER_SCRIPT linker_script
235 	| PARSING_VERSION_SCRIPT version_script
236 	| PARSING_DEFSYM defsym_expr
237         | PARSING_DYNAMIC_LIST dynamic_list_expr
238         | PARSING_SECTIONS_BLOCK sections_block
239         | PARSING_SECTION_COMMANDS section_cmds
240         | PARSING_MEMORY_DEF memory_defs
241 	;
242 
243 /* A file contains a list of commands.  */
244 linker_script:
245 	  linker_script file_cmd
246 	| /* empty */
247 	;
248 
249 /* A command which may appear at top level of a linker script.  */
250 file_cmd:
251 	  EXTERN '(' extern_name_list ')'
252 	| FORCE_COMMON_ALLOCATION
253 	    { script_set_common_allocation(closure, 1); }
254 	| GROUP
255 	    { script_start_group(closure); }
256 	  '(' input_list ')'
257 	    { script_end_group(closure); }
258 	| INHIBIT_COMMON_ALLOCATION
259 	    { script_set_common_allocation(closure, 0); }
260 	| INPUT '(' input_list ')'
261 	| MEMORY '{' memory_defs '}'
262         | OPTION '(' string ')'
263 	    { script_parse_option(closure, $3.value, $3.length); }
264 	| OUTPUT_FORMAT '(' string ')'
265 	    {
266 	      if (!script_check_output_format(closure, $3.value, $3.length,
267 					      NULL, 0, NULL, 0))
268 		YYABORT;
269 	    }
270 	| OUTPUT_FORMAT '(' string ',' string ',' string ')'
271 	    {
272 	      if (!script_check_output_format(closure, $3.value, $3.length,
273 					      $5.value, $5.length,
274 					      $7.value, $7.length))
275 		YYABORT;
276 	    }
277 	| PHDRS '{' phdrs_defs '}'
278 	| SEARCH_DIR '(' string ')'
279 	    { script_add_search_dir(closure, $3.value, $3.length); }
280 	| SECTIONS '{'
281 	    { script_start_sections(closure); }
282 	  sections_block '}'
283 	    { script_finish_sections(closure); }
284 	| TARGET_K '(' string ')'
285 	    { script_set_target(closure, $3.value, $3.length); }
286         | VERSIONK '{'
287             { script_push_lex_into_version_mode(closure); }
288           version_script '}'
289             { script_pop_lex_mode(closure); }
290 	| ENTRY '(' string ')'
291 	    { script_set_entry(closure, $3.value, $3.length); }
292 	| assignment end
293 	| ASSERT_K '(' parse_exp ',' string ')'
294 	    { script_add_assertion(closure, $3, $5.value, $5.length); }
295 	| INCLUDE string
296 	    { script_include_directive(PARSING_LINKER_SCRIPT, closure,
297 				       $2.value, $2.length); }
298 	| ignore_cmd
299 	| ';'
300 	;
301 
302 /* Top level commands which we ignore.  The GNU linker uses these to
303    select the output format, but we don't offer a choice.  Ignoring
304    these is more-or-less OK since most scripts simply explicitly
305    choose the default.  */
306 ignore_cmd:
307 	  OUTPUT_ARCH '(' string ')'
308 	;
309 
310 /* A list of external undefined symbols.  We put the lexer into
311    expression mode so that commas separate names; this is what the GNU
312    linker does.  */
313 
314 extern_name_list:
315 	    { script_push_lex_into_expression_mode(closure); }
316 	  extern_name_list_body
317 	    { script_pop_lex_mode(closure); }
318 	;
319 
320 extern_name_list_body:
321 	  string
322 	    { script_add_extern(closure, $1.value, $1.length); }
323 	| extern_name_list_body string
324 	    { script_add_extern(closure, $2.value, $2.length); }
325 	| extern_name_list_body ',' string
326 	    { script_add_extern(closure, $3.value, $3.length); }
327 	;
328 
329 /* A list of input file names.  */
330 input_list:
331 	  input_list_element
332 	| input_list opt_comma input_list_element
333 	;
334 
335 /* An input file name.  */
336 input_list_element:
337 	  string
338 	    { script_add_file(closure, $1.value, $1.length); }
339 	| '-' STRING
340 	    { script_add_library(closure, $2.value, $2.length); }
341 	| AS_NEEDED
342 	    { script_start_as_needed(closure); }
343 	  '(' input_list ')'
344 	    { script_end_as_needed(closure); }
345 	;
346 
347 /* Commands in a SECTIONS block.  */
348 sections_block:
349 	  sections_block section_block_cmd
350 	| /* empty */
351 	;
352 
353 /* A command which may appear within a SECTIONS block.  */
354 section_block_cmd:
355 	  ENTRY '(' string ')'
356 	    { script_set_entry(closure, $3.value, $3.length); }
357 	| assignment end
358 	| ASSERT_K '(' parse_exp ',' string ')'
359 	    { script_add_assertion(closure, $3, $5.value, $5.length); }
360 	| INCLUDE string
361 	    { script_include_directive(PARSING_SECTIONS_BLOCK, closure,
362 				       $2.value, $2.length); }
363 	| string section_header
364 	    { script_start_output_section(closure, $1.value, $1.length, &$2); }
365 	  '{' section_cmds '}' section_trailer
366 	    { script_finish_output_section(closure, &$7); }
367 	;
368 
369 /* The header of an output section in a SECTIONS block--everything
370    after the name.  */
371 section_header:
372 	    { script_push_lex_into_expression_mode(closure); }
373 	  opt_address_and_section_type opt_at opt_align opt_subalign
374 	    { script_pop_lex_mode(closure); }
375 	  opt_constraint
376 	    {
377 	      $$.address = $2.address;
378 	      $$.section_type = $2.section_type;
379 	      $$.load_address = $3;
380 	      $$.align = $4;
381 	      $$.subalign = $5;
382 	      $$.constraint = $7;
383 	    }
384 	;
385 
386 /* The optional address followed by the optional section type.  This
387    is a separate nonterminal to avoid a shift/reduce conflict on
388    '(' in section_header.  */
389 
390 opt_address_and_section_type:
391 	':'
392 	    {
393 	      $$.address = NULL;
394 	      $$.section_type = SCRIPT_SECTION_TYPE_NONE;
395 	    }
396 	| '(' ')' ':'
397 	    {
398 	      $$.address = NULL;
399 	      $$.section_type = SCRIPT_SECTION_TYPE_NONE;
400 	    }
401 	| exp ':'
402 	    {
403 	      $$.address = $1;
404 	      $$.section_type = SCRIPT_SECTION_TYPE_NONE;
405 	    }
406 	| exp '(' ')' ':'
407 	    {
408 	      $$.address = $1;
409 	      $$.section_type = SCRIPT_SECTION_TYPE_NONE;
410 	    }
411 	| '(' section_type ')' ':'
412 	    {
413 	      $$.address = NULL;
414 	      $$.section_type = $2;
415 	    }
416 	| exp '(' section_type ')' ':'
417 	    {
418 	      $$.address = $1;
419 	      $$.section_type = $3;
420 	    }
421 	;
422 
423 /* We only support NOLOAD.  */
424 section_type:
425 	NOLOAD
426 	    { $$ = SCRIPT_SECTION_TYPE_NOLOAD; }
427 	| DSECT
428 	    {
429 	      yyerror(closure, "DSECT section type is unsupported");
430 	      $$ = SCRIPT_SECTION_TYPE_DSECT;
431 	    }
432 	| COPY
433 	    {
434 	      yyerror(closure, "COPY section type is unsupported");
435 	      $$ = SCRIPT_SECTION_TYPE_COPY;
436 	    }
437 	| INFO
438 	    {
439 	      yyerror(closure, "INFO section type is unsupported");
440 	      $$ = SCRIPT_SECTION_TYPE_INFO;
441 	    }
442 	| OVERLAY
443 	    {
444 	      yyerror(closure, "OVERLAY section type is unsupported");
445 	      $$ = SCRIPT_SECTION_TYPE_OVERLAY;
446 	    }
447 	;
448 
449 /* The address at which an output section should be loaded.  */
450 opt_at:
451 	  /* empty */
452 	    { $$ = NULL; }
453 	| AT '(' exp ')'
454 	    { $$ = $3; }
455 	;
456 
457 /* The alignment of an output section.  */
458 opt_align:
459 	  /* empty */
460 	    { $$ = NULL; }
461 	| ALIGN_K '(' exp ')'
462 	    { $$ = $3; }
463 	;
464 
465 /* The input section alignment within an output section.  */
466 opt_subalign:
467 	  /* empty */
468 	    { $$ = NULL; }
469 	| SUBALIGN '(' exp ')'
470 	    { $$ = $3; }
471 	;
472 
473 /* A section constraint.  */
474 opt_constraint:
475 	  /* empty */
476 	    { $$ = CONSTRAINT_NONE; }
477 	| ONLY_IF_RO
478 	    { $$ = CONSTRAINT_ONLY_IF_RO; }
479 	| ONLY_IF_RW
480 	    { $$ = CONSTRAINT_ONLY_IF_RW; }
481 	| SPECIAL
482 	    { $$ = CONSTRAINT_SPECIAL; }
483 	;
484 
485 /* The trailer of an output section in a SECTIONS block.  */
486 section_trailer:
487 	  opt_memspec opt_at_memspec opt_phdr opt_fill opt_comma
488 	    {
489 	      $$.fill = $4;
490 	      $$.phdrs = $3;
491 	    }
492 	;
493 
494 /* A memory specification for an output section.  */
495 opt_memspec:
496 	  '>' string
497 	    { script_set_section_region(closure, $2.value, $2.length, 1); }
498 	| /* empty */
499 	;
500 
501 /* A memory specification for where to load an output section.  */
502 opt_at_memspec:
503 	  AT '>' string
504 	    { script_set_section_region(closure, $3.value, $3.length, 0); }
505 	| /* empty */
506 	;
507 
508 /* The program segment an output section should go into.  */
509 opt_phdr:
510 	  opt_phdr ':' string
511 	    { $$ = script_string_list_push_back($1, $3.value, $3.length); }
512 	| /* empty */
513 	    { $$ = NULL; }
514 	;
515 
516 /* The value to use to fill an output section.  FIXME: This does not
517    handle a string of arbitrary length.  */
518 opt_fill:
519 	  '=' parse_exp
520 	    { $$ = $2; }
521 	| /* empty */
522 	    { $$ = NULL; }
523 	;
524 
525 /* Commands which may appear within the description of an output
526    section in a SECTIONS block.  */
527 section_cmds:
528 	  /* empty */
529 	| section_cmds section_cmd
530 	;
531 
532 /* A command which may appear within the description of an output
533    section in a SECTIONS block.  */
534 section_cmd:
535 	  assignment end
536 	| input_section_spec
537 	| data_length '(' parse_exp ')'
538 	    { script_add_data(closure, $1, $3); }
539 	| ASSERT_K '(' parse_exp ',' string ')'
540 	    { script_add_assertion(closure, $3, $5.value, $5.length); }
541 	| FILL '(' parse_exp ')'
542 	    { script_add_fill(closure, $3); }
543 	| CONSTRUCTORS
544 	    {
545 	      /* The GNU linker uses CONSTRUCTORS for the a.out object
546 		 file format.  It does nothing when using ELF.  Since
547 		 some ELF linker scripts use it although it does
548 		 nothing, we accept it and ignore it.  */
549 	    }
550 	| SORT_BY_NAME '(' CONSTRUCTORS ')'
551 	| INCLUDE string
552 	    { script_include_directive(PARSING_SECTION_COMMANDS, closure,
553 				       $2.value, $2.length); }
554 	| ';'
555 	;
556 
557 /* The length of data which may appear within the description of an
558    output section in a SECTIONS block.  */
559 data_length:
560 	  QUAD
561 	    { $$ = QUAD; }
562 	| SQUAD
563 	    { $$ = SQUAD; }
564 	| LONG
565 	    { $$ = LONG; }
566 	| SHORT
567 	    { $$ = SHORT; }
568 	| BYTE
569 	    { $$ = BYTE; }
570 	;
571 
572 /* An input section specification.  This may appear within the
573    description of an output section in a SECTIONS block.  */
574 input_section_spec:
575 	  input_section_no_keep
576 	    { script_add_input_section(closure, &$1, 0); }
577 	| KEEP '(' input_section_no_keep ')'
578 	    { script_add_input_section(closure, &$3, 1); }
579 	;
580 
581 /* An input section specification within a KEEP clause.  */
582 input_section_no_keep:
583 	  string
584 	    {
585 	      $$.file.name = $1;
586 	      $$.file.sort = SORT_WILDCARD_NONE;
587 	      $$.input_sections.sections = NULL;
588 	      $$.input_sections.exclude = NULL;
589 	    }
590 	| wildcard_file '(' wildcard_sections ')'
591 	    {
592 	      $$.file = $1;
593 	      $$.input_sections = $3;
594 	    }
595 	;
596 
597 /* A wildcard file specification.  */
598 wildcard_file:
599 	  wildcard_name
600 	    {
601 	      $$.name = $1;
602 	      $$.sort = SORT_WILDCARD_NONE;
603 	    }
604 	| SORT_BY_NAME '(' wildcard_name ')'
605 	    {
606 	      $$.name = $3;
607 	      $$.sort = SORT_WILDCARD_BY_NAME;
608 	    }
609 	;
610 
611 /* A list of wild card section specifications.  */
612 wildcard_sections:
613 	  wildcard_sections opt_comma wildcard_section
614 	    {
615 	      $$.sections = script_string_sort_list_add($1.sections, &$3);
616 	      $$.exclude = $1.exclude;
617 	    }
618 	| wildcard_section
619 	    {
620 	      $$.sections = script_new_string_sort_list(&$1);
621 	      $$.exclude = NULL;
622 	    }
623 	| wildcard_sections opt_comma EXCLUDE_FILE '(' exclude_names ')'
624 	    {
625 	      $$.sections = $1.sections;
626 	      $$.exclude = script_string_list_append($1.exclude, $5);
627 	    }
628 	| EXCLUDE_FILE '(' exclude_names ')'
629 	    {
630 	      $$.sections = NULL;
631 	      $$.exclude = $3;
632 	    }
633 	;
634 
635 /* A single wild card specification.  */
636 wildcard_section:
637 	  wildcard_name
638 	    {
639 	      $$.name = $1;
640 	      $$.sort = SORT_WILDCARD_NONE;
641 	    }
642 	| SORT_BY_NAME '(' wildcard_section ')'
643 	    {
644 	      $$.name = $3.name;
645 	      switch ($3.sort)
646 		{
647 		case SORT_WILDCARD_NONE:
648 		  $$.sort = SORT_WILDCARD_BY_NAME;
649 		  break;
650 		case SORT_WILDCARD_BY_NAME:
651 		case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT:
652 		  break;
653 		case SORT_WILDCARD_BY_ALIGNMENT:
654 		case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME:
655 		  $$.sort = SORT_WILDCARD_BY_NAME_BY_ALIGNMENT;
656 		  break;
657 		default:
658 		  abort();
659 		}
660 	    }
661 	| SORT_BY_ALIGNMENT '(' wildcard_section ')'
662 	    {
663 	      $$.name = $3.name;
664 	      switch ($3.sort)
665 		{
666 		case SORT_WILDCARD_NONE:
667 		  $$.sort = SORT_WILDCARD_BY_ALIGNMENT;
668 		  break;
669 		case SORT_WILDCARD_BY_ALIGNMENT:
670 		case SORT_WILDCARD_BY_ALIGNMENT_BY_NAME:
671 		  break;
672 		case SORT_WILDCARD_BY_NAME:
673 		case SORT_WILDCARD_BY_NAME_BY_ALIGNMENT:
674 		  $$.sort = SORT_WILDCARD_BY_ALIGNMENT_BY_NAME;
675 		  break;
676 		default:
677 		  abort();
678 		}
679 	    }
680 	;
681 
682 /* A list of file names to exclude.  */
683 exclude_names:
684 	  exclude_names opt_comma wildcard_name
685 	    { $$ = script_string_list_push_back($1, $3.value, $3.length); }
686 	| wildcard_name
687 	    { $$ = script_new_string_list($1.value, $1.length); }
688 	;
689 
690 /* A single wildcard name.  We recognize '*' and '?' specially since
691    they are expression tokens.  */
692 wildcard_name:
693 	  string
694 	    { $$ = $1; }
695 	| '*'
696 	    {
697 	      $$.value = "*";
698 	      $$.length = 1;
699 	    }
700 	| '?'
701 	    {
702 	      $$.value = "?";
703 	      $$.length = 1;
704 	    }
705 	;
706 
707 /* A list of MEMORY definitions.  */
708 memory_defs:
709 	  memory_defs opt_comma memory_def
710 	| /* empty */
711 	;
712 
713 /* A single MEMORY definition.  */
714 memory_def:
715 	  string memory_attr ':' memory_origin '=' parse_exp opt_comma memory_length '=' parse_exp
716 	  { script_add_memory(closure, $1.value, $1.length, $2, $6, $10); }
717 	|
718 	  INCLUDE string
719 	  { script_include_directive(PARSING_MEMORY_DEF, closure,
720 				     $2.value, $2.length); }
721 	|
722 	;
723 
724 /* The (optional) attributes of a MEMORY region.  */
725 memory_attr:
726 	  '(' string ')'
727 	  { $$ = script_parse_memory_attr(closure, $2.value, $2.length, 0); }
728         | /* Inverted attributes. */
729 	  '(' '!' string ')'
730 	  { $$ = script_parse_memory_attr(closure, $3.value, $3.length, 1); }
731 	| /* empty */
732 	    { $$ = 0; }
733 	;
734 
735 memory_origin:
736           ORIGIN
737 	|
738 	  ORG
739 	|
740 	  'o'
741 	;
742 
743 memory_length:
744           LENGTH
745 	|
746 	  LEN
747 	|
748 	  'l'
749 	;
750 
751 /* A list of program header definitions.  */
752 phdrs_defs:
753 	  phdrs_defs phdr_def
754 	| /* empty */
755 	;
756 
757 /* A program header definition.  */
758 phdr_def:
759 	  string phdr_type phdr_info ';'
760 	    { script_add_phdr(closure, $1.value, $1.length, $2, &$3); }
761 	;
762 
763 /* A program header type.  The GNU linker accepts a general expression
764    here, but that would be a pain because we would have to dig into
765    the expression structure.  It's unlikely that anybody uses anything
766    other than a string or a number here, so that is all we expect.  */
767 phdr_type:
768 	  string
769 	    { $$ = script_phdr_string_to_type(closure, $1.value, $1.length); }
770 	| INTEGER
771 	    { $$ = $1; }
772 	;
773 
774 /* Additional information for a program header.  */
775 phdr_info:
776 	  /* empty */
777 	    { memset(&$$, 0, sizeof(struct Phdr_info)); }
778 	| string phdr_info
779 	    {
780 	      $$ = $2;
781 	      if ($1.length == 7 && strncmp($1.value, "FILEHDR", 7) == 0)
782 		$$.includes_filehdr = 1;
783 	      else
784 		yyerror(closure, "PHDRS syntax error");
785 	    }
786 	| PHDRS phdr_info
787 	    {
788 	      $$ = $2;
789 	      $$.includes_phdrs = 1;
790 	    }
791 	| string '(' INTEGER ')' phdr_info
792 	    {
793 	      $$ = $5;
794 	      if ($1.length == 5 && strncmp($1.value, "FLAGS", 5) == 0)
795 		{
796 		  $$.is_flags_valid = 1;
797 		  $$.flags = $3;
798 		}
799 	      else
800 		yyerror(closure, "PHDRS syntax error");
801 	    }
802 	| AT '(' parse_exp ')' phdr_info
803 	    {
804 	      $$ = $5;
805 	      $$.load_address = $3;
806 	    }
807 	;
808 
809 /* Set a symbol to a value.  */
810 assignment:
811 	  string '=' parse_exp
812 	    { script_set_symbol(closure, $1.value, $1.length, $3, 0, 0); }
813 	| string PLUSEQ parse_exp
814 	    {
815 	      Expression_ptr s = script_exp_string($1.value, $1.length);
816 	      Expression_ptr e = script_exp_binary_add(s, $3);
817 	      script_set_symbol(closure, $1.value, $1.length, e, 0, 0);
818 	    }
819 	| string MINUSEQ parse_exp
820 	    {
821 	      Expression_ptr s = script_exp_string($1.value, $1.length);
822 	      Expression_ptr e = script_exp_binary_sub(s, $3);
823 	      script_set_symbol(closure, $1.value, $1.length, e, 0, 0);
824 	    }
825 	| string MULTEQ parse_exp
826 	    {
827 	      Expression_ptr s = script_exp_string($1.value, $1.length);
828 	      Expression_ptr e = script_exp_binary_mult(s, $3);
829 	      script_set_symbol(closure, $1.value, $1.length, e, 0, 0);
830 	    }
831 	| string DIVEQ parse_exp
832 	    {
833 	      Expression_ptr s = script_exp_string($1.value, $1.length);
834 	      Expression_ptr e = script_exp_binary_div(s, $3);
835 	      script_set_symbol(closure, $1.value, $1.length, e, 0, 0);
836 	    }
837 	| string LSHIFTEQ parse_exp
838 	    {
839 	      Expression_ptr s = script_exp_string($1.value, $1.length);
840 	      Expression_ptr e = script_exp_binary_lshift(s, $3);
841 	      script_set_symbol(closure, $1.value, $1.length, e, 0, 0);
842 	    }
843 	| string RSHIFTEQ parse_exp
844 	    {
845 	      Expression_ptr s = script_exp_string($1.value, $1.length);
846 	      Expression_ptr e = script_exp_binary_rshift(s, $3);
847 	      script_set_symbol(closure, $1.value, $1.length, e, 0, 0);
848 	    }
849 	| string ANDEQ parse_exp
850 	    {
851 	      Expression_ptr s = script_exp_string($1.value, $1.length);
852 	      Expression_ptr e = script_exp_binary_bitwise_and(s, $3);
853 	      script_set_symbol(closure, $1.value, $1.length, e, 0, 0);
854 	    }
855 	| string OREQ parse_exp
856 	    {
857 	      Expression_ptr s = script_exp_string($1.value, $1.length);
858 	      Expression_ptr e = script_exp_binary_bitwise_or(s, $3);
859 	      script_set_symbol(closure, $1.value, $1.length, e, 0, 0);
860 	    }
861 	| PROVIDE '(' string '=' parse_exp ')'
862 	    { script_set_symbol(closure, $3.value, $3.length, $5, 1, 0); }
863 	| PROVIDE_HIDDEN '(' string '=' parse_exp ')'
864 	    { script_set_symbol(closure, $3.value, $3.length, $5, 1, 1); }
865 	;
866 
867 /* Parse an expression, putting the lexer into the right mode.  */
868 parse_exp:
869 	    { script_push_lex_into_expression_mode(closure); }
870 	  exp
871 	    {
872 	      script_pop_lex_mode(closure);
873 	      $$ = $2;
874 	    }
875 	;
876 
877 /* An expression.  */
878 exp:
879 	  '(' exp ')'
880 	    { $$ = $2; }
881 	| '-' exp %prec UNARY
882 	    { $$ = script_exp_unary_minus($2); }
883 	| '!' exp %prec UNARY
884 	    { $$ = script_exp_unary_logical_not($2); }
885 	| '~' exp %prec UNARY
886 	    { $$ = script_exp_unary_bitwise_not($2); }
887 	| '+' exp %prec UNARY
888 	    { $$ = $2; }
889 	| exp '*' exp
890 	    { $$ = script_exp_binary_mult($1, $3); }
891 	| exp '/' exp
892 	    { $$ = script_exp_binary_div($1, $3); }
893 	| exp '%' exp
894 	    { $$ = script_exp_binary_mod($1, $3); }
895 	| exp '+' exp
896 	    { $$ = script_exp_binary_add($1, $3); }
897 	| exp '-' exp
898 	    { $$ = script_exp_binary_sub($1, $3); }
899 	| exp LSHIFT exp
900 	    { $$ = script_exp_binary_lshift($1, $3); }
901 	| exp RSHIFT exp
902 	    { $$ = script_exp_binary_rshift($1, $3); }
903 	| exp EQ exp
904 	    { $$ = script_exp_binary_eq($1, $3); }
905 	| exp NE exp
906 	    { $$ = script_exp_binary_ne($1, $3); }
907 	| exp LE exp
908 	    { $$ = script_exp_binary_le($1, $3); }
909 	| exp GE exp
910 	    { $$ = script_exp_binary_ge($1, $3); }
911 	| exp '<' exp
912 	    { $$ = script_exp_binary_lt($1, $3); }
913 	| exp '>' exp
914 	    { $$ = script_exp_binary_gt($1, $3); }
915 	| exp '&' exp
916 	    { $$ = script_exp_binary_bitwise_and($1, $3); }
917 	| exp '^' exp
918 	    { $$ = script_exp_binary_bitwise_xor($1, $3); }
919 	| exp '|' exp
920 	    { $$ = script_exp_binary_bitwise_or($1, $3); }
921 	| exp ANDAND exp
922 	    { $$ = script_exp_binary_logical_and($1, $3); }
923 	| exp OROR exp
924 	    { $$ = script_exp_binary_logical_or($1, $3); }
925 	| exp '?' exp ':' exp
926 	    { $$ = script_exp_trinary_cond($1, $3, $5); }
927 	| INTEGER
928 	    { $$ = script_exp_integer($1); }
929 	| string
930 	    { $$ = script_symbol(closure, $1.value, $1.length); }
931 	| MAX_K '(' exp ',' exp ')'
932 	    { $$ = script_exp_function_max($3, $5); }
933 	| MIN_K '(' exp ',' exp ')'
934 	    { $$ = script_exp_function_min($3, $5); }
935 	| DEFINED '(' string ')'
936 	    { $$ = script_exp_function_defined($3.value, $3.length); }
937 	| SIZEOF_HEADERS
938 	    { $$ = script_exp_function_sizeof_headers(); }
939 	| ALIGNOF '(' string ')'
940 	    { $$ = script_exp_function_alignof($3.value, $3.length); }
941 	| SIZEOF '(' string ')'
942 	    { $$ = script_exp_function_sizeof($3.value, $3.length); }
943 	| ADDR '(' string ')'
944 	    { $$ = script_exp_function_addr($3.value, $3.length); }
945 	| LOADADDR '(' string ')'
946 	    { $$ = script_exp_function_loadaddr($3.value, $3.length); }
947 	| ORIGIN '(' string ')'
948 	    { $$ = script_exp_function_origin(closure, $3.value, $3.length); }
949 	| LENGTH '(' string ')'
950 	    { $$ = script_exp_function_length(closure, $3.value, $3.length); }
951 	| CONSTANT '(' string ')'
952 	    { $$ = script_exp_function_constant($3.value, $3.length); }
953 	| ABSOLUTE '(' exp ')'
954 	    { $$ = script_exp_function_absolute($3); }
955 	| ALIGN_K '(' exp ')'
956 	    { $$ = script_exp_function_align(script_exp_string(".", 1), $3); }
957 	| ALIGN_K '(' exp ',' exp ')'
958 	    { $$ = script_exp_function_align($3, $5); }
959 	| BLOCK '(' exp ')'
960 	    { $$ = script_exp_function_align(script_exp_string(".", 1), $3); }
961 	| DATA_SEGMENT_ALIGN '(' exp ',' exp ')'
962 	    {
963 	      script_data_segment_align(closure);
964 	      $$ = script_exp_function_data_segment_align($3, $5);
965 	    }
966 	| DATA_SEGMENT_RELRO_END '(' exp ',' exp ')'
967 	    {
968 	      script_data_segment_relro_end(closure);
969 	      $$ = script_exp_function_data_segment_relro_end($3, $5);
970 	    }
971 	| DATA_SEGMENT_END '(' exp ')'
972 	    { $$ = script_exp_function_data_segment_end($3); }
973 	| SEGMENT_START '(' string ',' exp ')'
974 	    {
975 	      $$ = script_exp_function_segment_start($3.value, $3.length, $5);
976 	      /* We need to take note of any SEGMENT_START expressions
977 		 because they change the behaviour of -Ttext, -Tdata and
978 		 -Tbss options.  */
979 	      script_saw_segment_start_expression(closure);
980 	    }
981 	| ASSERT_K '(' exp ',' string ')'
982 	    { $$ = script_exp_function_assert($3, $5.value, $5.length); }
983 	;
984 
985 /* Handle the --defsym option.  */
986 defsym_expr:
987 	  string '=' parse_exp
988 	    { script_set_symbol(closure, $1.value, $1.length, $3, 0, 0); }
989 	;
990 
991 /* Handle the --dynamic-list option.  A dynamic list has the format
992    { sym1; sym2; extern "C++" { namespace::sym3 }; };
993    We store the symbol we see in the "local" list; that is where
994    Command_line::in_dynamic_list() will look to do its check.
995    TODO(csilvers): More than one of these brace-lists can appear, and
996    should just be merged and treated as a single list.  */
997 dynamic_list_expr: dynamic_list_nodes ;
998 
999 dynamic_list_nodes:
1000 	  dynamic_list_node
1001 	| dynamic_list_nodes dynamic_list_node
1002         ;
1003 
1004 dynamic_list_node:
1005           '{' vers_defns ';' '}' ';'
1006             { script_new_vers_node (closure, NULL, $2); }
1007         ;
1008 
1009 /* A version script.  */
1010 version_script:
1011 	  vers_nodes
1012 	;
1013 
1014 vers_nodes:
1015 	  vers_node
1016 	| vers_nodes vers_node
1017 	;
1018 
1019 vers_node:
1020 	  '{' vers_tag '}' ';'
1021 	    {
1022 	      script_register_vers_node (closure, NULL, 0, $2, NULL);
1023 	    }
1024 	| string '{' vers_tag '}' ';'
1025 	    {
1026 	      script_register_vers_node (closure, $1.value, $1.length, $3,
1027 					 NULL);
1028 	    }
1029 	| string '{' vers_tag '}' verdep ';'
1030 	    {
1031 	      script_register_vers_node (closure, $1.value, $1.length, $3, $5);
1032 	    }
1033 	;
1034 
1035 verdep:
1036 	  string
1037 	    {
1038 	      $$ = script_add_vers_depend (closure, NULL, $1.value, $1.length);
1039 	    }
1040 	| verdep string
1041 	    {
1042 	      $$ = script_add_vers_depend (closure, $1, $2.value, $2.length);
1043 	    }
1044 	;
1045 
1046 vers_tag:
1047 	  /* empty */
1048 	    { $$ = script_new_vers_node (closure, NULL, NULL); }
1049 	| vers_defns ';'
1050 	    { $$ = script_new_vers_node (closure, $1, NULL); }
1051 	| GLOBAL ':' vers_defns ';'
1052 	    { $$ = script_new_vers_node (closure, $3, NULL); }
1053 	| LOCAL ':' vers_defns ';'
1054 	    { $$ = script_new_vers_node (closure, NULL, $3); }
1055 	| GLOBAL ':' vers_defns ';' LOCAL ':' vers_defns ';'
1056 	    { $$ = script_new_vers_node (closure, $3, $7); }
1057 	;
1058 
1059 /* Here is one of the rare places we care about the distinction
1060    between STRING and QUOTED_STRING.  For QUOTED_STRING, we do exact
1061    matching on the pattern, so we pass in true for the exact_match
1062    parameter.  For STRING, we do glob matching and pass in false.  */
1063 vers_defns:
1064 	  STRING
1065 	    {
1066 	      $$ = script_new_vers_pattern (closure, NULL, $1.value,
1067 					    $1.length, 0);
1068 	    }
1069 	| QUOTED_STRING
1070 	    {
1071 	      $$ = script_new_vers_pattern (closure, NULL, $1.value,
1072 					    $1.length, 1);
1073 	    }
1074 	| vers_defns ';' STRING
1075 	    {
1076 	      $$ = script_new_vers_pattern (closure, $1, $3.value,
1077                                             $3.length, 0);
1078 	    }
1079 	| vers_defns ';' QUOTED_STRING
1080 	    {
1081 	      $$ = script_new_vers_pattern (closure, $1, $3.value,
1082                                             $3.length, 1);
1083 	    }
1084         | /* Push string on the language stack. */
1085           EXTERN string '{'
1086 	    { version_script_push_lang (closure, $2.value, $2.length); }
1087 	  vers_defns opt_semicolon '}'
1088 	    {
1089 	      $$ = $5;
1090 	      version_script_pop_lang(closure);
1091 	    }
1092         | /* Push string on the language stack.  This is more complicated
1093              than the other cases because we need to merge the linked-list
1094              state from the pre-EXTERN defns and the post-EXTERN defns.  */
1095           vers_defns ';' EXTERN string '{'
1096 	    { version_script_push_lang (closure, $4.value, $4.length); }
1097 	  vers_defns opt_semicolon '}'
1098 	    {
1099 	      $$ = script_merge_expressions ($1, $7);
1100 	      version_script_pop_lang(closure);
1101 	    }
1102         | EXTERN  // "extern" as a symbol name
1103 	    {
1104 	      $$ = script_new_vers_pattern (closure, NULL, "extern",
1105 					    sizeof("extern") - 1, 1);
1106 	    }
1107 	| vers_defns ';' EXTERN
1108 	    {
1109 	      $$ = script_new_vers_pattern (closure, $1, "extern",
1110 					    sizeof("extern") - 1, 1);
1111 	    }
1112 	;
1113 
1114 /* A string can be either a STRING or a QUOTED_STRING.  Almost all the
1115    time we don't care, and we use this rule.  */
1116 string:
1117           STRING
1118 	    { $$ = $1; }
1119 	| QUOTED_STRING
1120 	    { $$ = $1; }
1121 	;
1122 
1123 /* Some statements require a terminator, which may be a semicolon or a
1124    comma.  */
1125 end:
1126 	  ';'
1127 	| ','
1128 	;
1129 
1130 /* An optional semicolon.  */
1131 opt_semicolon:
1132 	  ';'
1133 	|  /* empty */
1134 	;
1135 
1136 /* An optional comma.  */
1137 opt_comma:
1138 	  ','
1139 	| /* empty */
1140 	;
1141 
1142 %%
1143