1 /* This module handles expression trees.
2 Copyright (C) 1991-2018 Free Software Foundation, Inc.
3 Written by Steve Chamberlain of Cygnus Support <sac@cygnus.com>.
5 This file is part of the GNU Binutils.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
20 MA 02110-1301, USA. */
23 /* This module is in charge of working out the contents of expressions.
25 It has to keep track of the relative/absness of a symbol etc. This
26 is done by keeping all values in a struct (an etree_value_type)
27 which contains a value, a section to which it is relative and a
41 #include "libiberty.h"
42 #include "safe-ctype.h"
44 static void exp_fold_tree_1 (etree_type
*);
45 static bfd_vma
align_n (bfd_vma
, bfd_vma
);
47 segment_type
*segments
;
49 struct ldexp_control expld
;
51 /* This structure records symbols for which we need to keep track of
52 definedness for use in the DEFINED () test. It is also used in
53 making absolute symbols section relative late in the link. */
55 struct definedness_hash_entry
57 struct bfd_hash_entry root
;
59 /* If this symbol was assigned from "dot" outside of an output
60 section statement, the section we'd like it relative to. */
63 /* Low bits of iteration count. Symbols with matching iteration have
64 been defined in this pass over the script. */
65 unsigned int iteration
: 8;
67 /* Symbol was defined by an object file. */
68 unsigned int by_object
: 1;
71 static struct bfd_hash_table definedness_table
;
73 /* Print the string representation of the given token. Surround it
74 with spaces if INFIX_P is TRUE. */
77 exp_print_token (token_code_type code
, int infix_p
)
104 { LOG2CEIL
, "LOG2CEIL" },
105 { ALIGN_K
, "ALIGN" },
112 { SECTIONS
, "SECTIONS" },
113 { SIZEOF_HEADERS
, "SIZEOF_HEADERS" },
114 { MEMORY
, "MEMORY" },
115 { DEFINED
, "DEFINED" },
116 { TARGET_K
, "TARGET" },
117 { SEARCH_DIR
, "SEARCH_DIR" },
121 { ALIGNOF
, "ALIGNOF" },
122 { SIZEOF
, "SIZEOF" },
124 { LOADADDR
, "LOADADDR" },
125 { CONSTANT
, "CONSTANT" },
126 { ABSOLUTE
, "ABSOLUTE" },
129 { ASSERT_K
, "ASSERT" },
130 { REL
, "relocatable" },
131 { DATA_SEGMENT_ALIGN
, "DATA_SEGMENT_ALIGN" },
132 { DATA_SEGMENT_RELRO_END
, "DATA_SEGMENT_RELRO_END" },
133 { DATA_SEGMENT_END
, "DATA_SEGMENT_END" },
134 { ORIGIN
, "ORIGIN" },
135 { LENGTH
, "LENGTH" },
136 { SEGMENT_START
, "SEGMENT_START" }
140 for (idx
= 0; idx
< ARRAY_SIZE (table
); idx
++)
141 if (table
[idx
].code
== code
)
145 fputc (' ', config
.map_file
);
147 if (idx
< ARRAY_SIZE (table
))
148 fputs (table
[idx
].name
, config
.map_file
);
150 fputc (code
, config
.map_file
);
152 fprintf (config
.map_file
, "<code %d>", code
);
155 fputc (' ', config
.map_file
);
161 bfd_vma value
= expld
.result
.value
;
163 bfd_boolean round_up
= FALSE
;
168 /* If more than one bit is set in the value we will need to round up. */
169 if ((value
> 1) && (value
& 1))
176 expld
.result
.section
= NULL
;
177 expld
.result
.value
= result
;
183 if (expld
.result
.section
!= NULL
)
184 expld
.result
.value
+= expld
.result
.section
->vma
;
185 expld
.result
.section
= bfd_abs_section_ptr
;
186 expld
.rel_from_abs
= FALSE
;
190 new_abs (bfd_vma value
)
192 expld
.result
.valid_p
= TRUE
;
193 expld
.result
.section
= bfd_abs_section_ptr
;
194 expld
.result
.value
= value
;
195 expld
.result
.str
= NULL
;
199 exp_intop (bfd_vma value
)
201 etree_type
*new_e
= (etree_type
*) stat_alloc (sizeof (new_e
->value
));
202 new_e
->type
.node_code
= INT
;
203 new_e
->type
.filename
= ldlex_filename ();
204 new_e
->type
.lineno
= lineno
;
205 new_e
->value
.value
= value
;
206 new_e
->value
.str
= NULL
;
207 new_e
->type
.node_class
= etree_value
;
212 exp_bigintop (bfd_vma value
, char *str
)
214 etree_type
*new_e
= (etree_type
*) stat_alloc (sizeof (new_e
->value
));
215 new_e
->type
.node_code
= INT
;
216 new_e
->type
.filename
= ldlex_filename ();
217 new_e
->type
.lineno
= lineno
;
218 new_e
->value
.value
= value
;
219 new_e
->value
.str
= str
;
220 new_e
->type
.node_class
= etree_value
;
224 /* Build an expression representing an unnamed relocatable value. */
227 exp_relop (asection
*section
, bfd_vma value
)
229 etree_type
*new_e
= (etree_type
*) stat_alloc (sizeof (new_e
->rel
));
230 new_e
->type
.node_code
= REL
;
231 new_e
->type
.filename
= ldlex_filename ();
232 new_e
->type
.lineno
= lineno
;
233 new_e
->type
.node_class
= etree_rel
;
234 new_e
->rel
.section
= section
;
235 new_e
->rel
.value
= value
;
240 new_number (bfd_vma value
)
242 expld
.result
.valid_p
= TRUE
;
243 expld
.result
.value
= value
;
244 expld
.result
.str
= NULL
;
245 expld
.result
.section
= NULL
;
249 new_rel (bfd_vma value
, asection
*section
)
251 expld
.result
.valid_p
= TRUE
;
252 expld
.result
.value
= value
;
253 expld
.result
.str
= NULL
;
254 expld
.result
.section
= section
;
258 new_rel_from_abs (bfd_vma value
)
260 asection
*s
= expld
.section
;
262 expld
.rel_from_abs
= TRUE
;
263 expld
.result
.valid_p
= TRUE
;
264 expld
.result
.value
= value
- s
->vma
;
265 expld
.result
.str
= NULL
;
266 expld
.result
.section
= s
;
269 /* New-function for the definedness hash table. */
271 static struct bfd_hash_entry
*
272 definedness_newfunc (struct bfd_hash_entry
*entry
,
273 struct bfd_hash_table
*table ATTRIBUTE_UNUSED
,
274 const char *name ATTRIBUTE_UNUSED
)
276 struct definedness_hash_entry
*ret
= (struct definedness_hash_entry
*) entry
;
279 ret
= (struct definedness_hash_entry
*)
280 bfd_hash_allocate (table
, sizeof (struct definedness_hash_entry
));
283 einfo (_("%F%P: bfd_hash_allocate failed creating symbol %s\n"), name
);
290 /* Called during processing of linker script script expressions.
291 For symbols assigned in a linker script, return a struct describing
292 where the symbol is defined relative to the current expression,
293 otherwise return NULL. */
295 static struct definedness_hash_entry
*
296 symbol_defined (const char *name
)
298 return ((struct definedness_hash_entry
*)
299 bfd_hash_lookup (&definedness_table
, name
, FALSE
, FALSE
));
302 /* Update the definedness state of NAME. Return FALSE if script symbol
303 is multiply defining a strong symbol in an object. */
306 update_definedness (const char *name
, struct bfd_link_hash_entry
*h
)
309 struct definedness_hash_entry
*defentry
310 = (struct definedness_hash_entry
*)
311 bfd_hash_lookup (&definedness_table
, name
, TRUE
, FALSE
);
313 if (defentry
== NULL
)
314 einfo (_("%F%P: bfd_hash_lookup failed creating symbol %s\n"), name
);
316 /* If the symbol was already defined, and not by a script, then it
317 must be defined by an object file or by the linker target code. */
320 && (h
->type
== bfd_link_hash_defined
321 || h
->type
== bfd_link_hash_defweak
322 || h
->type
== bfd_link_hash_common
))
324 defentry
->by_object
= 1;
325 if (h
->type
== bfd_link_hash_defined
326 && h
->u
.def
.section
->output_section
!= NULL
331 defentry
->iteration
= lang_statement_iteration
;
332 defentry
->final_sec
= bfd_abs_section_ptr
;
333 if (expld
.phase
== lang_final_phase_enum
334 && expld
.rel_from_abs
335 && expld
.result
.section
== bfd_abs_section_ptr
)
336 defentry
->final_sec
= section_for_dot ();
341 fold_segment_end (seg_align_type
*seg
)
343 if (expld
.phase
== lang_first_phase_enum
344 || expld
.section
!= bfd_abs_section_ptr
)
346 expld
.result
.valid_p
= FALSE
;
348 else if (seg
->phase
== exp_seg_align_seen
349 || seg
->phase
== exp_seg_relro_seen
)
351 seg
->phase
= exp_seg_end_seen
;
352 seg
->end
= expld
.result
.value
;
354 else if (seg
->phase
== exp_seg_done
355 || seg
->phase
== exp_seg_adjust
356 || seg
->phase
== exp_seg_relro_adjust
)
361 expld
.result
.valid_p
= FALSE
;
365 fold_unary (etree_type
*tree
)
367 exp_fold_tree_1 (tree
->unary
.child
);
368 if (expld
.result
.valid_p
)
370 switch (tree
->type
.node_code
)
373 if (expld
.phase
!= lang_first_phase_enum
)
374 new_rel_from_abs (align_n (expld
.dot
, expld
.result
.value
));
376 expld
.result
.valid_p
= FALSE
;
388 expld
.result
.value
= ~expld
.result
.value
;
392 expld
.result
.value
= !expld
.result
.value
;
396 expld
.result
.value
= -expld
.result
.value
;
400 /* Return next place aligned to value. */
401 if (expld
.phase
!= lang_first_phase_enum
)
404 expld
.result
.value
= align_n (expld
.dot
, expld
.result
.value
);
407 expld
.result
.valid_p
= FALSE
;
410 case DATA_SEGMENT_END
:
411 fold_segment_end (&expld
.dataseg
);
421 /* Arithmetic operators, bitwise AND, bitwise OR and XOR keep the
422 section of one of their operands only when the other operand is a
423 plain number. Losing the section when operating on two symbols,
424 ie. a result of a plain number, is required for subtraction and
425 XOR. It's justifiable for the other operations on the grounds that
426 adding, multiplying etc. two section relative values does not
427 really make sense unless they are just treated as numbers.
428 The same argument could be made for many expressions involving one
429 symbol and a number. For example, "1 << x" and "100 / x" probably
430 should not be given the section of x. The trouble is that if we
431 fuss about such things the rules become complex and it is onerous
432 to document ld expression evaluation. */
434 arith_result_section (const etree_value_type
*lhs
)
436 if (expld
.result
.section
== lhs
->section
)
438 if (expld
.section
== bfd_abs_section_ptr
439 && !config
.sane_expr
)
440 /* Duplicate the insanity in exp_fold_tree_1 case etree_value. */
441 expld
.result
.section
= bfd_abs_section_ptr
;
443 expld
.result
.section
= NULL
;
448 fold_segment_align (seg_align_type
*seg
, etree_value_type
*lhs
)
450 seg
->relro
= exp_seg_relro_start
;
451 if (expld
.phase
== lang_first_phase_enum
452 || expld
.section
!= bfd_abs_section_ptr
)
453 expld
.result
.valid_p
= FALSE
;
456 bfd_vma maxpage
= lhs
->value
;
457 bfd_vma commonpage
= expld
.result
.value
;
459 expld
.result
.value
= align_n (expld
.dot
, maxpage
);
460 if (seg
->phase
== exp_seg_relro_adjust
)
461 expld
.result
.value
= seg
->base
;
462 else if (seg
->phase
== exp_seg_adjust
)
464 if (commonpage
< maxpage
)
465 expld
.result
.value
+= ((expld
.dot
+ commonpage
- 1)
466 & (maxpage
- commonpage
));
470 expld
.result
.value
+= expld
.dot
& (maxpage
- 1);
471 if (seg
->phase
== exp_seg_done
)
475 else if (seg
->phase
== exp_seg_none
)
477 seg
->phase
= exp_seg_align_seen
;
478 seg
->base
= expld
.result
.value
;
479 seg
->pagesize
= commonpage
;
480 seg
->maxpagesize
= maxpage
;
484 expld
.result
.valid_p
= FALSE
;
490 fold_segment_relro_end (seg_align_type
*seg
, etree_value_type
*lhs
)
492 /* Operands swapped! XXX_SEGMENT_RELRO_END(offset,exp) has offset
493 in expld.result and exp in lhs. */
494 seg
->relro
= exp_seg_relro_end
;
495 seg
->relro_offset
= expld
.result
.value
;
496 if (expld
.phase
== lang_first_phase_enum
497 || expld
.section
!= bfd_abs_section_ptr
)
498 expld
.result
.valid_p
= FALSE
;
499 else if (seg
->phase
== exp_seg_align_seen
500 || seg
->phase
== exp_seg_adjust
501 || seg
->phase
== exp_seg_relro_adjust
502 || seg
->phase
== exp_seg_done
)
504 if (seg
->phase
== exp_seg_align_seen
505 || seg
->phase
== exp_seg_relro_adjust
)
506 seg
->relro_end
= lhs
->value
+ expld
.result
.value
;
508 if (seg
->phase
== exp_seg_relro_adjust
509 && (seg
->relro_end
& (seg
->pagesize
- 1)))
511 seg
->relro_end
+= seg
->pagesize
- 1;
512 seg
->relro_end
&= ~(seg
->pagesize
- 1);
513 expld
.result
.value
= seg
->relro_end
- expld
.result
.value
;
516 expld
.result
.value
= lhs
->value
;
518 if (seg
->phase
== exp_seg_align_seen
)
519 seg
->phase
= exp_seg_relro_seen
;
522 expld
.result
.valid_p
= FALSE
;
526 fold_binary (etree_type
*tree
)
528 etree_value_type lhs
;
529 exp_fold_tree_1 (tree
->binary
.lhs
);
531 /* The SEGMENT_START operator is special because its first
532 operand is a string, not the name of a symbol. Note that the
533 operands have been swapped, so binary.lhs is second (default)
534 operand, binary.rhs is first operand. */
535 if (expld
.result
.valid_p
&& tree
->type
.node_code
== SEGMENT_START
)
537 bfd_vma value
= expld
.result
.value
;
538 const char *segment_name
;
541 /* Check to see if the user has overridden the default
543 segment_name
= tree
->binary
.rhs
->name
.name
;
544 for (seg
= segments
; seg
; seg
= seg
->next
)
545 if (strcmp (seg
->name
, segment_name
) == 0)
548 && config
.magic_demand_paged
549 && config
.maxpagesize
!= 0
550 && (seg
->value
% config
.maxpagesize
) != 0)
551 einfo (_("%P: warning: address of `%s' "
552 "isn't multiple of maximum page size\n"),
558 new_rel_from_abs (value
);
563 exp_fold_tree_1 (tree
->binary
.rhs
);
564 expld
.result
.valid_p
&= lhs
.valid_p
;
566 if (expld
.result
.valid_p
)
568 if (lhs
.section
!= expld
.result
.section
)
570 /* If the values are from different sections, and neither is
571 just a number, make both the source arguments absolute. */
572 if (expld
.result
.section
!= NULL
573 && lhs
.section
!= NULL
)
576 lhs
.value
+= lhs
.section
->vma
;
577 lhs
.section
= bfd_abs_section_ptr
;
580 /* If the rhs is just a number, keep the lhs section. */
581 else if (expld
.result
.section
== NULL
)
583 expld
.result
.section
= lhs
.section
;
584 /* Make this NULL so that we know one of the operands
585 was just a number, for later tests. */
589 /* At this point we know that both operands have the same
590 section, or at least one of them is a plain number. */
592 switch (tree
->type
.node_code
)
596 expld.result.value = lhs.value y expld.result.value; \
597 arith_result_section (&lhs); \
600 /* Comparison operators, logical AND, and logical OR always
601 return a plain number. */
604 expld.result.value = lhs.value y expld.result.value; \
605 expld.result.section = NULL; \
626 if (expld
.result
.value
!= 0)
627 expld
.result
.value
= ((bfd_signed_vma
) lhs
.value
628 % (bfd_signed_vma
) expld
.result
.value
);
629 else if (expld
.phase
!= lang_mark_phase_enum
)
630 einfo (_("%F%P:%pS %% by zero\n"), tree
->binary
.rhs
);
631 arith_result_section (&lhs
);
635 if (expld
.result
.value
!= 0)
636 expld
.result
.value
= ((bfd_signed_vma
) lhs
.value
637 / (bfd_signed_vma
) expld
.result
.value
);
638 else if (expld
.phase
!= lang_mark_phase_enum
)
639 einfo (_("%F%P:%pS / by zero\n"), tree
->binary
.rhs
);
640 arith_result_section (&lhs
);
644 if (lhs
.value
> expld
.result
.value
)
645 expld
.result
.value
= lhs
.value
;
649 if (lhs
.value
< expld
.result
.value
)
650 expld
.result
.value
= lhs
.value
;
654 expld
.result
.value
= align_n (lhs
.value
, expld
.result
.value
);
657 case DATA_SEGMENT_ALIGN
:
658 fold_segment_align (&expld
.dataseg
, &lhs
);
661 case DATA_SEGMENT_RELRO_END
:
662 fold_segment_relro_end (&expld
.dataseg
, &lhs
);
672 fold_trinary (etree_type
*tree
)
674 struct bfd_link_hash_entry
*save
= expld
.assign_src
;
676 exp_fold_tree_1 (tree
->trinary
.cond
);
677 expld
.assign_src
= save
;
678 if (expld
.result
.valid_p
)
679 exp_fold_tree_1 (expld
.result
.value
681 : tree
->trinary
.rhs
);
685 fold_name (etree_type
*tree
)
687 struct bfd_link_hash_entry
*h
;
688 struct definedness_hash_entry
*def
;
690 memset (&expld
.result
, 0, sizeof (expld
.result
));
692 switch (tree
->type
.node_code
)
695 link_info
.load_phdrs
= 1;
696 if (expld
.phase
!= lang_first_phase_enum
)
698 bfd_vma hdr_size
= 0;
699 /* Don't find the real header size if only marking sections;
700 The bfd function may cache incorrect data. */
701 if (expld
.phase
!= lang_mark_phase_enum
)
702 hdr_size
= bfd_sizeof_headers (link_info
.output_bfd
, &link_info
);
703 new_number (hdr_size
);
708 h
= bfd_wrapped_link_hash_lookup (link_info
.output_bfd
,
712 new_number (h
!= NULL
713 && (h
->type
== bfd_link_hash_defined
714 || h
->type
== bfd_link_hash_defweak
715 || h
->type
== bfd_link_hash_common
)
717 || (def
= symbol_defined (tree
->name
.name
)) == NULL
719 || def
->iteration
== (lang_statement_iteration
& 255)));
723 if (expld
.assign_name
!= NULL
724 && strcmp (expld
.assign_name
, tree
->name
.name
) == 0)
726 /* Self-assignment is only allowed for absolute symbols
727 defined in a linker script. */
728 h
= bfd_wrapped_link_hash_lookup (link_info
.output_bfd
,
733 && (h
->type
== bfd_link_hash_defined
734 || h
->type
== bfd_link_hash_defweak
)
735 && h
->u
.def
.section
== bfd_abs_section_ptr
736 && (def
= symbol_defined (tree
->name
.name
)) != NULL
737 && def
->iteration
== (lang_statement_iteration
& 255)))
738 expld
.assign_name
= NULL
;
740 if (tree
->name
.name
[0] == '.' && tree
->name
.name
[1] == 0)
741 new_rel_from_abs (expld
.dot
);
744 h
= bfd_wrapped_link_hash_lookup (link_info
.output_bfd
,
749 einfo (_("%F%P: bfd_link_hash_lookup failed: %E\n"));
750 else if (h
->type
== bfd_link_hash_defined
751 || h
->type
== bfd_link_hash_defweak
)
753 asection
*output_section
;
755 output_section
= h
->u
.def
.section
->output_section
;
756 if (output_section
== NULL
)
758 if (expld
.phase
<= lang_mark_phase_enum
)
759 new_rel (h
->u
.def
.value
, h
->u
.def
.section
);
761 einfo (_("%X%P:%pS: unresolvable symbol `%s'"
762 " referenced in expression\n"),
763 tree
, tree
->name
.name
);
765 else if (output_section
== bfd_abs_section_ptr
766 && (expld
.section
!= bfd_abs_section_ptr
767 || config
.sane_expr
))
768 new_number (h
->u
.def
.value
+ h
->u
.def
.section
->output_offset
);
770 new_rel (h
->u
.def
.value
+ h
->u
.def
.section
->output_offset
,
773 else if (expld
.phase
== lang_final_phase_enum
774 || (expld
.phase
!= lang_mark_phase_enum
775 && expld
.assigning_to_dot
))
776 einfo (_("%F%P:%pS: undefined symbol `%s'"
777 " referenced in expression\n"),
778 tree
, tree
->name
.name
);
779 else if (h
->type
== bfd_link_hash_new
)
781 h
->type
= bfd_link_hash_undefined
;
782 h
->u
.undef
.abfd
= NULL
;
783 if (h
->u
.undef
.next
== NULL
&& h
!= link_info
.hash
->undefs_tail
)
784 bfd_link_add_undef (link_info
.hash
, h
);
786 if (expld
.assign_src
== NULL
)
787 expld
.assign_src
= h
;
789 expld
.assign_src
= (struct bfd_link_hash_entry
*) - 1;
794 if (expld
.phase
!= lang_first_phase_enum
)
796 lang_output_section_statement_type
*os
;
798 os
= lang_output_section_find (tree
->name
.name
);
801 if (expld
.phase
== lang_final_phase_enum
)
802 einfo (_("%F%P:%pS: undefined section `%s'"
803 " referenced in expression\n"),
804 tree
, tree
->name
.name
);
806 else if (os
->processed_vma
)
807 new_rel (0, os
->bfd_section
);
812 if (expld
.phase
!= lang_first_phase_enum
)
814 lang_output_section_statement_type
*os
;
816 os
= lang_output_section_find (tree
->name
.name
);
819 if (expld
.phase
== lang_final_phase_enum
)
820 einfo (_("%F%P:%pS: undefined section `%s'"
821 " referenced in expression\n"),
822 tree
, tree
->name
.name
);
824 else if (os
->processed_lma
)
826 if (os
->load_base
== NULL
)
827 new_abs (os
->bfd_section
->lma
);
830 exp_fold_tree_1 (os
->load_base
);
831 if (expld
.result
.valid_p
)
840 if (expld
.phase
!= lang_first_phase_enum
)
842 lang_output_section_statement_type
*os
;
844 os
= lang_output_section_find (tree
->name
.name
);
847 if (expld
.phase
== lang_final_phase_enum
)
848 einfo (_("%F%P:%pS: undefined section `%s'"
849 " referenced in expression\n"),
850 tree
, tree
->name
.name
);
853 else if (os
->bfd_section
!= NULL
)
857 if (tree
->type
.node_code
== SIZEOF
)
858 val
= (os
->bfd_section
->size
859 / bfd_octets_per_byte (link_info
.output_bfd
));
861 val
= (bfd_vma
)1 << os
->bfd_section
->alignment_power
;
872 if (expld
.phase
!= lang_first_phase_enum
)
874 lang_memory_region_type
*mem
;
876 mem
= lang_memory_region_lookup (tree
->name
.name
, FALSE
);
878 new_number (mem
->length
);
880 einfo (_("%F%P:%pS: undefined MEMORY region `%s'"
881 " referenced in expression\n"),
882 tree
, tree
->name
.name
);
888 if (expld
.phase
!= lang_first_phase_enum
)
890 lang_memory_region_type
*mem
;
892 mem
= lang_memory_region_lookup (tree
->name
.name
, FALSE
);
894 new_rel_from_abs (mem
->origin
);
896 einfo (_("%F%P:%pS: undefined MEMORY region `%s'"
897 " referenced in expression\n"),
898 tree
, tree
->name
.name
);
903 if (strcmp (tree
->name
.name
, "MAXPAGESIZE") == 0)
904 new_number (config
.maxpagesize
);
905 else if (strcmp (tree
->name
.name
, "COMMONPAGESIZE") == 0)
906 new_number (config
.commonpagesize
);
908 einfo (_("%F%P:%pS: unknown constant `%s' referenced in expression\n"),
909 tree
, tree
->name
.name
);
918 /* Return true if TREE is '.'. */
921 is_dot (const etree_type
*tree
)
923 return (tree
->type
.node_class
== etree_name
924 && tree
->type
.node_code
== NAME
925 && tree
->name
.name
[0] == '.'
926 && tree
->name
.name
[1] == 0);
929 /* Return true if TREE is a constant equal to VAL. */
932 is_value (const etree_type
*tree
, bfd_vma val
)
934 return (tree
->type
.node_class
== etree_value
935 && tree
->value
.value
== val
);
938 /* Return true if TREE is an absolute symbol equal to VAL defined in
942 is_sym_value (const etree_type
*tree
, bfd_vma val
)
944 struct bfd_link_hash_entry
*h
;
945 struct definedness_hash_entry
*def
;
947 return (tree
->type
.node_class
== etree_name
948 && tree
->type
.node_code
== NAME
949 && (def
= symbol_defined (tree
->name
.name
)) != NULL
950 && def
->iteration
== (lang_statement_iteration
& 255)
951 && (h
= bfd_wrapped_link_hash_lookup (link_info
.output_bfd
,
954 FALSE
, FALSE
, TRUE
)) != NULL
956 && h
->type
== bfd_link_hash_defined
957 && h
->u
.def
.section
== bfd_abs_section_ptr
958 && h
->u
.def
.value
== val
);
961 /* Return true if TREE is ". != 0". */
964 is_dot_ne_0 (const etree_type
*tree
)
966 return (tree
->type
.node_class
== etree_binary
967 && tree
->type
.node_code
== NE
968 && is_dot (tree
->binary
.lhs
)
969 && is_value (tree
->binary
.rhs
, 0));
972 /* Return true if TREE is ". = . + 0" or ". = . + sym" where sym is an
973 absolute constant with value 0 defined in a linker script. */
976 is_dot_plus_0 (const etree_type
*tree
)
978 return (tree
->type
.node_class
== etree_binary
979 && tree
->type
.node_code
== '+'
980 && is_dot (tree
->binary
.lhs
)
981 && (is_value (tree
->binary
.rhs
, 0)
982 || is_sym_value (tree
->binary
.rhs
, 0)));
985 /* Return true if TREE is "ALIGN (. != 0 ? some_expression : 1)". */
988 is_align_conditional (const etree_type
*tree
)
990 if (tree
->type
.node_class
== etree_unary
991 && tree
->type
.node_code
== ALIGN_K
)
993 tree
= tree
->unary
.child
;
994 return (tree
->type
.node_class
== etree_trinary
995 && is_dot_ne_0 (tree
->trinary
.cond
)
996 && is_value (tree
->trinary
.rhs
, 1));
1002 exp_fold_tree_1 (etree_type
*tree
)
1006 memset (&expld
.result
, 0, sizeof (expld
.result
));
1010 switch (tree
->type
.node_class
)
1013 if (expld
.section
== bfd_abs_section_ptr
1014 && !config
.sane_expr
)
1015 new_abs (tree
->value
.value
);
1017 new_number (tree
->value
.value
);
1018 expld
.result
.str
= tree
->value
.str
;
1022 if (expld
.phase
!= lang_first_phase_enum
)
1024 asection
*output_section
= tree
->rel
.section
->output_section
;
1025 new_rel (tree
->rel
.value
+ tree
->rel
.section
->output_offset
,
1029 memset (&expld
.result
, 0, sizeof (expld
.result
));
1033 exp_fold_tree_1 (tree
->assert_s
.child
);
1034 if (expld
.phase
== lang_final_phase_enum
&& !expld
.result
.value
)
1035 einfo ("%X%P: %s\n", tree
->assert_s
.message
);
1047 fold_trinary (tree
);
1052 case etree_provided
:
1053 if (tree
->assign
.dst
[0] == '.' && tree
->assign
.dst
[1] == 0)
1055 if (tree
->type
.node_class
!= etree_assign
)
1056 einfo (_("%F%P:%pS can not PROVIDE assignment to"
1057 " location counter\n"), tree
);
1058 if (expld
.phase
!= lang_first_phase_enum
)
1060 /* Notify the folder that this is an assignment to dot. */
1061 expld
.assigning_to_dot
= TRUE
;
1062 exp_fold_tree_1 (tree
->assign
.src
);
1063 expld
.assigning_to_dot
= FALSE
;
1065 /* If we are assigning to dot inside an output section
1066 arrange to keep the section, except for certain
1067 expressions that evaluate to zero. We ignore . = 0,
1068 . = . + 0, and . = ALIGN (. != 0 ? expr : 1).
1069 We can't ignore all expressions that evaluate to zero
1070 because an otherwise empty section might have padding
1071 added by an alignment expression that changes with
1072 relaxation. Such a section might have zero size
1073 before relaxation and so be stripped incorrectly. */
1074 if (expld
.phase
== lang_mark_phase_enum
1075 && expld
.section
!= bfd_abs_section_ptr
1076 && expld
.section
!= bfd_und_section_ptr
1077 && !(expld
.result
.valid_p
1078 && expld
.result
.value
== 0
1079 && (is_value (tree
->assign
.src
, 0)
1080 || is_sym_value (tree
->assign
.src
, 0)
1081 || is_dot_plus_0 (tree
->assign
.src
)
1082 || is_align_conditional (tree
->assign
.src
))))
1083 expld
.section
->flags
|= SEC_KEEP
;
1085 if (!expld
.result
.valid_p
1086 || expld
.section
== bfd_und_section_ptr
)
1088 if (expld
.phase
!= lang_mark_phase_enum
)
1089 einfo (_("%F%P:%pS invalid assignment to"
1090 " location counter\n"), tree
);
1092 else if (expld
.dotp
== NULL
)
1093 einfo (_("%F%P:%pS assignment to location counter"
1094 " invalid outside of SECTIONS\n"), tree
);
1096 /* After allocation, assignment to dot should not be
1097 done inside an output section since allocation adds a
1098 padding statement that effectively duplicates the
1100 else if (expld
.phase
<= lang_allocating_phase_enum
1101 || expld
.section
== bfd_abs_section_ptr
)
1105 nextdot
= expld
.result
.value
;
1106 if (expld
.result
.section
!= NULL
)
1107 nextdot
+= expld
.result
.section
->vma
;
1109 nextdot
+= expld
.section
->vma
;
1110 if (nextdot
< expld
.dot
1111 && expld
.section
!= bfd_abs_section_ptr
)
1112 einfo (_("%F%P:%pS cannot move location counter backwards"
1113 " (from %V to %V)\n"),
1114 tree
, expld
.dot
, nextdot
);
1117 expld
.dot
= nextdot
;
1118 *expld
.dotp
= nextdot
;
1123 memset (&expld
.result
, 0, sizeof (expld
.result
));
1127 struct bfd_link_hash_entry
*h
= NULL
;
1129 if (tree
->type
.node_class
== etree_provide
)
1131 h
= bfd_link_hash_lookup (link_info
.hash
, tree
->assign
.dst
,
1132 FALSE
, FALSE
, TRUE
);
1134 || !(h
->type
== bfd_link_hash_new
1135 || h
->type
== bfd_link_hash_undefined
1136 || h
->type
== bfd_link_hash_undefweak
1139 /* Do nothing. The symbol was never referenced, or
1140 was defined in some object file. Note that
1141 undefweak symbols are defined by PROVIDE. This
1142 is to support glibc use of __rela_iplt_start and
1143 similar weak references. */
1148 expld
.assign_name
= tree
->assign
.dst
;
1149 expld
.assign_src
= NULL
;
1150 exp_fold_tree_1 (tree
->assign
.src
);
1151 /* expld.assign_name remaining equal to tree->assign.dst
1152 below indicates the evaluation of tree->assign.src did
1153 not use the value of tree->assign.dst. We don't allow
1154 self assignment until the final phase for two reasons:
1155 1) Expressions are evaluated multiple times. With
1156 relaxation, the number of times may vary.
1157 2) Section relative symbol values cannot be correctly
1158 converted to absolute values, as is required by many
1159 expressions, until final section sizing is complete. */
1160 if (expld
.phase
== lang_final_phase_enum
1161 || expld
.assign_name
!= NULL
)
1163 if (tree
->type
.node_class
== etree_provide
)
1164 tree
->type
.node_class
= etree_provided
;
1168 h
= bfd_link_hash_lookup (link_info
.hash
, tree
->assign
.dst
,
1171 einfo (_("%F%P:%s: hash creation failed\n"),
1175 /* If the expression is not valid then fake a zero value. In
1176 the final phase any errors will already have been raised,
1177 in earlier phases we want to create this definition so
1178 that it can be seen by other expressions. */
1179 if (!expld
.result
.valid_p
1180 && h
->type
== bfd_link_hash_new
)
1182 expld
.result
.value
= 0;
1183 expld
.result
.section
= NULL
;
1184 expld
.result
.valid_p
= TRUE
;
1187 if (expld
.result
.valid_p
)
1189 if (expld
.result
.section
== NULL
)
1190 expld
.result
.section
= expld
.section
;
1191 if (!update_definedness (tree
->assign
.dst
, h
) && 0)
1193 /* Symbol was already defined. For now this error
1194 is disabled because it causes failures in the ld
1195 testsuite: ld-elf/var1, ld-scripts/defined5, and
1196 ld-scripts/pr14962. Some of these no doubt
1197 reflect scripts used in the wild. */
1198 (*link_info
.callbacks
->multiple_definition
)
1199 (&link_info
, h
, link_info
.output_bfd
,
1200 expld
.result
.section
, expld
.result
.value
);
1202 h
->type
= bfd_link_hash_defined
;
1203 h
->u
.def
.value
= expld
.result
.value
;
1204 h
->u
.def
.section
= expld
.result
.section
;
1205 h
->linker_def
= ! tree
->assign
.type
.lineno
;
1206 h
->ldscript_def
= 1;
1207 h
->rel_from_abs
= expld
.rel_from_abs
;
1208 if (tree
->assign
.hidden
)
1209 bfd_link_hide_symbol (link_info
.output_bfd
,
1212 /* Copy the symbol type if this is an expression only
1213 referencing a single symbol. (If the expression
1214 contains ternary conditions, ignoring symbols on
1216 if (expld
.assign_src
!= NULL
1217 && (expld
.assign_src
1218 != (struct bfd_link_hash_entry
*) -1))
1219 bfd_copy_link_hash_symbol_type (link_info
.output_bfd
, h
,
1223 expld
.assign_name
= NULL
;
1233 memset (&expld
.result
, 0, sizeof (expld
.result
));
1239 exp_fold_tree (etree_type
*tree
, asection
*current_section
, bfd_vma
*dotp
)
1241 expld
.rel_from_abs
= FALSE
;
1244 expld
.section
= current_section
;
1245 exp_fold_tree_1 (tree
);
1249 exp_fold_tree_no_dot (etree_type
*tree
)
1251 expld
.rel_from_abs
= FALSE
;
1254 expld
.section
= bfd_abs_section_ptr
;
1255 exp_fold_tree_1 (tree
);
1259 exp_value_fold (etree_type
*tree
)
1261 exp_fold_tree_no_dot (tree
);
1262 if (expld
.result
.valid_p
)
1264 tree
->type
.node_code
= INT
;
1265 tree
->value
.value
= expld
.result
.value
;
1266 tree
->value
.str
= NULL
;
1267 tree
->type
.node_class
= etree_value
;
1271 #define MAX(a, b) ((a) > (b) ? (a) : (b))
1274 exp_binop (int code
, etree_type
*lhs
, etree_type
*rhs
)
1276 etree_type
*new_e
= (etree_type
*) stat_alloc (MAX (sizeof (new_e
->binary
),
1277 sizeof (new_e
->value
)));
1278 new_e
->type
.node_code
= code
;
1279 new_e
->type
.filename
= lhs
->type
.filename
;
1280 new_e
->type
.lineno
= lhs
->type
.lineno
;
1281 new_e
->binary
.lhs
= lhs
;
1282 new_e
->binary
.rhs
= rhs
;
1283 new_e
->type
.node_class
= etree_binary
;
1284 if (lhs
->type
.node_class
== etree_value
1285 && rhs
->type
.node_class
== etree_value
1287 && code
!= DATA_SEGMENT_ALIGN
1288 && code
!= DATA_SEGMENT_RELRO_END
)
1289 exp_value_fold (new_e
);
1294 exp_trinop (int code
, etree_type
*cond
, etree_type
*lhs
, etree_type
*rhs
)
1296 etree_type
*new_e
= (etree_type
*) stat_alloc (MAX (sizeof (new_e
->trinary
),
1297 sizeof (new_e
->value
)));
1298 new_e
->type
.node_code
= code
;
1299 new_e
->type
.filename
= cond
->type
.filename
;
1300 new_e
->type
.lineno
= cond
->type
.lineno
;
1301 new_e
->trinary
.lhs
= lhs
;
1302 new_e
->trinary
.cond
= cond
;
1303 new_e
->trinary
.rhs
= rhs
;
1304 new_e
->type
.node_class
= etree_trinary
;
1305 if (cond
->type
.node_class
== etree_value
1306 && lhs
->type
.node_class
== etree_value
1307 && rhs
->type
.node_class
== etree_value
)
1308 exp_value_fold (new_e
);
1313 exp_unop (int code
, etree_type
*child
)
1315 etree_type
*new_e
= (etree_type
*) stat_alloc (MAX (sizeof (new_e
->unary
),
1316 sizeof (new_e
->value
)));
1317 new_e
->unary
.type
.node_code
= code
;
1318 new_e
->unary
.type
.filename
= child
->type
.filename
;
1319 new_e
->unary
.type
.lineno
= child
->type
.lineno
;
1320 new_e
->unary
.child
= child
;
1321 new_e
->unary
.type
.node_class
= etree_unary
;
1322 if (child
->type
.node_class
== etree_value
1326 && code
!= DATA_SEGMENT_END
)
1327 exp_value_fold (new_e
);
1332 exp_nameop (int code
, const char *name
)
1334 etree_type
*new_e
= (etree_type
*) stat_alloc (sizeof (new_e
->name
));
1336 new_e
->name
.type
.node_code
= code
;
1337 new_e
->name
.type
.filename
= ldlex_filename ();
1338 new_e
->name
.type
.lineno
= lineno
;
1339 new_e
->name
.name
= name
;
1340 new_e
->name
.type
.node_class
= etree_name
;
1346 exp_assop (const char *dst
,
1348 enum node_tree_enum
class,
1353 n
= (etree_type
*) stat_alloc (sizeof (n
->assign
));
1354 n
->assign
.type
.node_code
= '=';
1355 n
->assign
.type
.filename
= src
->type
.filename
;
1356 n
->assign
.type
.lineno
= src
->type
.lineno
;
1357 n
->assign
.type
.node_class
= class;
1358 n
->assign
.src
= src
;
1359 n
->assign
.dst
= dst
;
1360 n
->assign
.hidden
= hidden
;
1364 /* Handle linker script assignments and HIDDEN. */
1367 exp_assign (const char *dst
, etree_type
*src
, bfd_boolean hidden
)
1369 return exp_assop (dst
, src
, etree_assign
, hidden
);
1372 /* Handle --defsym command-line option. */
1375 exp_defsym (const char *dst
, etree_type
*src
)
1377 return exp_assop (dst
, src
, etree_assign
, FALSE
);
1380 /* Handle PROVIDE. */
1383 exp_provide (const char *dst
, etree_type
*src
, bfd_boolean hidden
)
1385 return exp_assop (dst
, src
, etree_provide
, hidden
);
1388 /* Handle ASSERT. */
1391 exp_assert (etree_type
*exp
, const char *message
)
1395 n
= (etree_type
*) stat_alloc (sizeof (n
->assert_s
));
1396 n
->assert_s
.type
.node_code
= '!';
1397 n
->assert_s
.type
.filename
= exp
->type
.filename
;
1398 n
->assert_s
.type
.lineno
= exp
->type
.lineno
;
1399 n
->assert_s
.type
.node_class
= etree_assert
;
1400 n
->assert_s
.child
= exp
;
1401 n
->assert_s
.message
= message
;
1406 exp_print_tree (etree_type
*tree
)
1408 bfd_boolean function_like
;
1410 if (config
.map_file
== NULL
)
1411 config
.map_file
= stderr
;
1415 minfo ("NULL TREE\n");
1419 switch (tree
->type
.node_class
)
1422 minfo ("0x%v", tree
->value
.value
);
1425 if (tree
->rel
.section
->owner
!= NULL
)
1426 minfo ("%pB:", tree
->rel
.section
->owner
);
1427 minfo ("%s+0x%v", tree
->rel
.section
->name
, tree
->rel
.value
);
1430 fputs (tree
->assign
.dst
, config
.map_file
);
1431 exp_print_token (tree
->type
.node_code
, TRUE
);
1432 exp_print_tree (tree
->assign
.src
);
1435 case etree_provided
:
1436 fprintf (config
.map_file
, "PROVIDE (%s = ", tree
->assign
.dst
);
1437 exp_print_tree (tree
->assign
.src
);
1438 fputc (')', config
.map_file
);
1441 function_like
= FALSE
;
1442 switch (tree
->type
.node_code
)
1447 case DATA_SEGMENT_ALIGN
:
1448 case DATA_SEGMENT_RELRO_END
:
1449 function_like
= TRUE
;
1452 /* Special handling because arguments are in reverse order and
1453 the segment name is quoted. */
1454 exp_print_token (tree
->type
.node_code
, FALSE
);
1455 fputs (" (\"", config
.map_file
);
1456 exp_print_tree (tree
->binary
.rhs
);
1457 fputs ("\", ", config
.map_file
);
1458 exp_print_tree (tree
->binary
.lhs
);
1459 fputc (')', config
.map_file
);
1464 exp_print_token (tree
->type
.node_code
, FALSE
);
1465 fputc (' ', config
.map_file
);
1467 fputc ('(', config
.map_file
);
1468 exp_print_tree (tree
->binary
.lhs
);
1470 fprintf (config
.map_file
, ", ");
1472 exp_print_token (tree
->type
.node_code
, TRUE
);
1473 exp_print_tree (tree
->binary
.rhs
);
1474 fputc (')', config
.map_file
);
1477 exp_print_tree (tree
->trinary
.cond
);
1478 fputc ('?', config
.map_file
);
1479 exp_print_tree (tree
->trinary
.lhs
);
1480 fputc (':', config
.map_file
);
1481 exp_print_tree (tree
->trinary
.rhs
);
1484 exp_print_token (tree
->unary
.type
.node_code
, FALSE
);
1485 if (tree
->unary
.child
)
1487 fprintf (config
.map_file
, " (");
1488 exp_print_tree (tree
->unary
.child
);
1489 fputc (')', config
.map_file
);
1494 fprintf (config
.map_file
, "ASSERT (");
1495 exp_print_tree (tree
->assert_s
.child
);
1496 fprintf (config
.map_file
, ", %s)", tree
->assert_s
.message
);
1500 if (tree
->type
.node_code
== NAME
)
1501 fputs (tree
->name
.name
, config
.map_file
);
1504 exp_print_token (tree
->type
.node_code
, FALSE
);
1505 if (tree
->name
.name
)
1506 fprintf (config
.map_file
, " (%s)", tree
->name
.name
);
1516 exp_get_vma (etree_type
*tree
, bfd_vma def
, char *name
)
1520 exp_fold_tree_no_dot (tree
);
1521 if (expld
.result
.valid_p
)
1522 return expld
.result
.value
;
1523 else if (name
!= NULL
&& expld
.phase
!= lang_mark_phase_enum
)
1524 einfo (_("%F%P:%pS: nonconstant expression for %s\n"),
1530 /* Return the smallest non-negative integer such that two raised to
1531 that power is at least as large as the vma evaluated at TREE, if
1532 TREE is a non-NULL expression that can be resolved. If TREE is
1533 NULL or cannot be resolved, return -1. */
1536 exp_get_power (etree_type
*tree
, char *name
)
1538 bfd_vma x
= exp_get_vma (tree
, -1, name
);
1542 if (x
== (bfd_vma
) -1)
1545 for (n
= 0, p2
= 1; p2
< x
; ++n
, p2
<<= 1)
1553 exp_get_fill (etree_type
*tree
, fill_type
*def
, char *name
)
1562 exp_fold_tree_no_dot (tree
);
1563 if (!expld
.result
.valid_p
)
1565 if (name
!= NULL
&& expld
.phase
!= lang_mark_phase_enum
)
1566 einfo (_("%F%P:%pS: nonconstant expression for %s\n"),
1571 if (expld
.result
.str
!= NULL
&& (len
= strlen (expld
.result
.str
)) != 0)
1575 fill
= (fill_type
*) xmalloc ((len
+ 1) / 2 + sizeof (*fill
) - 1);
1576 fill
->size
= (len
+ 1) / 2;
1578 s
= (unsigned char *) expld
.result
.str
;
1586 digit
= (digit
- 'A' + '0' + 10) & 0xf;
1600 fill
= (fill_type
*) xmalloc (4 + sizeof (*fill
) - 1);
1601 val
= expld
.result
.value
;
1602 fill
->data
[0] = (val
>> 24) & 0xff;
1603 fill
->data
[1] = (val
>> 16) & 0xff;
1604 fill
->data
[2] = (val
>> 8) & 0xff;
1605 fill
->data
[3] = (val
>> 0) & 0xff;
1612 exp_get_abs_int (etree_type
*tree
, int def
, char *name
)
1616 exp_fold_tree_no_dot (tree
);
1618 if (expld
.result
.valid_p
)
1620 if (expld
.result
.section
!= NULL
)
1621 expld
.result
.value
+= expld
.result
.section
->vma
;
1622 return expld
.result
.value
;
1624 else if (name
!= NULL
&& expld
.phase
!= lang_mark_phase_enum
)
1626 einfo (_("%F%P:%pS: nonconstant expression for %s\n"),
1634 align_n (bfd_vma value
, bfd_vma align
)
1639 value
= (value
+ align
- 1) / align
;
1640 return value
* align
;
1646 /* The value "13" is ad-hoc, somewhat related to the expected number of
1647 assignments in a linker script. */
1648 if (!bfd_hash_table_init_n (&definedness_table
,
1649 definedness_newfunc
,
1650 sizeof (struct definedness_hash_entry
),
1652 einfo (_("%F%P: can not create hash table: %E\n"));
1655 /* Convert absolute symbols defined by a script from "dot" (also
1656 SEGMENT_START or ORIGIN) outside of an output section statement,
1657 to section relative. */
1660 set_sym_sections (struct bfd_hash_entry
*bh
, void *inf ATTRIBUTE_UNUSED
)
1662 struct definedness_hash_entry
*def
= (struct definedness_hash_entry
*) bh
;
1663 if (def
->final_sec
!= bfd_abs_section_ptr
)
1665 struct bfd_link_hash_entry
*h
;
1666 h
= bfd_link_hash_lookup (link_info
.hash
, bh
->string
,
1667 FALSE
, FALSE
, TRUE
);
1669 && h
->type
== bfd_link_hash_defined
1670 && h
->u
.def
.section
== bfd_abs_section_ptr
)
1672 h
->u
.def
.value
-= def
->final_sec
->vma
;
1673 h
->u
.def
.section
= def
->final_sec
;
1680 ldexp_finalize_syms (void)
1682 bfd_hash_traverse (&definedness_table
, set_sym_sections
, NULL
);
1688 bfd_hash_table_free (&definedness_table
);