1 /* This module handles expression trees.
2 Copyright (C) 1991-2015 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 /* Symbol was defined by an object file. */
64 unsigned int by_object : 1;
66 /* Symbols was defined by a script. */
67 unsigned int by_script : 1;
69 /* Low bit of iteration count. Symbols with matching iteration have
70 been defined in this pass over the script. */
71 unsigned int iteration : 1;
74 static struct bfd_hash_table definedness_table;
76 /* Print the string representation of the given token. Surround it
77 with spaces if INFIX_P is TRUE. */
80 exp_print_token (token_code_type code, int infix_p)
107 { LOG2CEIL, "LOG2CEIL" },
108 { ALIGN_K, "ALIGN" },
115 { SECTIONS, "SECTIONS" },
116 { SIZEOF_HEADERS, "SIZEOF_HEADERS" },
117 { MEMORY, "MEMORY" },
118 { DEFINED, "DEFINED" },
119 { TARGET_K, "TARGET" },
120 { SEARCH_DIR, "SEARCH_DIR" },
124 { ALIGNOF, "ALIGNOF" },
125 { SIZEOF, "SIZEOF" },
127 { LOADADDR, "LOADADDR" },
128 { CONSTANT, "CONSTANT" },
129 { ABSOLUTE, "ABSOLUTE" },
132 { ASSERT_K, "ASSERT" },
133 { REL, "relocatable" },
134 { DATA_SEGMENT_ALIGN, "DATA_SEGMENT_ALIGN" },
135 { DATA_SEGMENT_RELRO_END, "DATA_SEGMENT_RELRO_END" },
136 { DATA_SEGMENT_END, "DATA_SEGMENT_END" },
137 { ORIGIN, "ORIGIN" },
138 { LENGTH, "LENGTH" },
139 { SEGMENT_START, "SEGMENT_START" }
143 for (idx = 0; idx < ARRAY_SIZE (table); idx++)
144 if (table[idx].code == code)
148 fputc (' ', config.map_file);
150 if (idx < ARRAY_SIZE (table))
151 fputs (table[idx].name, config.map_file);
153 fputc (code, config.map_file);
155 fprintf (config.map_file, "<code %d>", code);
158 fputc (' ', config.map_file);
164 bfd_vma value = expld.result.value;
166 bfd_boolean round_up = FALSE;
171 /* If more than one bit is set in the value we will need to round up. */
172 if ((value > 1) && (value & 1))
179 expld.result.section = NULL;
180 expld.result.value = result;
186 if (expld.result.section != NULL)
187 expld.result.value += expld.result.section->vma;
188 expld.result.section = bfd_abs_section_ptr;
189 expld.rel_from_abs = FALSE;
193 new_abs (bfd_vma value)
195 expld.result.valid_p = TRUE;
196 expld.result.section = bfd_abs_section_ptr;
197 expld.result.value = value;
198 expld.result.str = NULL;
202 exp_intop (bfd_vma value)
204 etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->value));
205 new_e->type.node_code = INT;
206 new_e->type.filename = ldlex_filename ();
207 new_e->type.lineno = lineno;
208 new_e->value.value = value;
209 new_e->value.str = NULL;
210 new_e->type.node_class = etree_value;
215 exp_bigintop (bfd_vma value, char *str)
217 etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->value));
218 new_e->type.node_code = INT;
219 new_e->type.filename = ldlex_filename ();
220 new_e->type.lineno = lineno;
221 new_e->value.value = value;
222 new_e->value.str = str;
223 new_e->type.node_class = etree_value;
227 /* Build an expression representing an unnamed relocatable value. */
230 exp_relop (asection *section, bfd_vma value)
232 etree_type *new_e = (etree_type *) stat_alloc (sizeof (new_e->rel));
233 new_e->type.node_code = REL;
234 new_e->type.filename = ldlex_filename ();
235 new_e->type.lineno = lineno;
236 new_e->type.node_class = etree_rel;
237 new_e->rel.section = section;
238 new_e->rel.value = value;
243 new_number (bfd_vma value)
245 expld.result.valid_p = TRUE;
246 expld.result.value = value;
247 expld.result.str = NULL;
248 expld.result.section = NULL;
252 new_rel (bfd_vma value, asection *section)
254 expld.result.valid_p = TRUE;
255 expld.result.value = value;
256 expld.result.str = NULL;
257 expld.result.section = section;
261 new_rel_from_abs (bfd_vma value)
263 asection *s = expld.section;
265 expld.rel_from_abs = TRUE;
266 expld.result.valid_p = TRUE;
267 expld.result.value = value - s->vma;
268 expld.result.str = NULL;
269 expld.result.section = s;
272 /* New-function for the definedness hash table. */
274 static struct bfd_hash_entry *
275 definedness_newfunc (struct bfd_hash_entry *entry,
276 struct bfd_hash_table *table ATTRIBUTE_UNUSED,
277 const char *name ATTRIBUTE_UNUSED)
279 struct definedness_hash_entry *ret = (struct definedness_hash_entry *) entry;
282 ret = (struct definedness_hash_entry *)
283 bfd_hash_allocate (table, sizeof (struct definedness_hash_entry));
286 einfo (_("%P%F: bfd_hash_allocate failed creating symbol %s\n"), name);
294 /* Called during processing of linker script script expressions.
295 For symbols assigned in a linker script, return a struct describing
296 where the symbol is defined relative to the current expression,
297 otherwise return NULL. */
299 static struct definedness_hash_entry *
300 symbol_defined (const char *name)
302 return ((struct definedness_hash_entry *)
303 bfd_hash_lookup (&definedness_table, name, FALSE, FALSE));
306 /* Update the definedness state of NAME. Return FALSE if script symbol
307 is multiply defining a strong symbol in an object. */
310 update_definedness (const char *name, struct bfd_link_hash_entry *h)
313 struct definedness_hash_entry *defentry
314 = (struct definedness_hash_entry *)
315 bfd_hash_lookup (&definedness_table, name, TRUE, FALSE);
317 if (defentry == NULL)
318 einfo (_("%P%F: bfd_hash_lookup failed creating symbol %s\n"), name);
320 /* If the symbol was already defined, and not by a script, then it
321 must be defined by an object file or by the linker target code. */
323 if (!defentry->by_script
324 && (h->type == bfd_link_hash_defined
325 || h->type == bfd_link_hash_defweak
326 || h->type == bfd_link_hash_common))
328 defentry->by_object = 1;
329 if (h->type == bfd_link_hash_defined
330 && h->u.def.section->output_section != NULL
335 defentry->by_script = 1;
336 defentry->iteration = lang_statement_iteration;
337 defentry->final_sec = bfd_abs_section_ptr;
338 if (expld.phase == lang_final_phase_enum
339 && expld.rel_from_abs
340 && expld.result.section == bfd_abs_section_ptr)
341 defentry->final_sec = section_for_dot ();
346 fold_unary (etree_type *tree)
348 exp_fold_tree_1 (tree->unary.child);
349 if (expld.result.valid_p)
351 switch (tree->type.node_code)
354 if (expld.phase != lang_first_phase_enum)
355 new_rel_from_abs (align_n (expld.dot, expld.result.value));
357 expld.result.valid_p = FALSE;
369 expld.result.value = ~expld.result.value;
373 expld.result.value = !expld.result.value;
377 expld.result.value = -expld.result.value;
381 /* Return next place aligned to value. */
382 if (expld.phase != lang_first_phase_enum)
385 expld.result.value = align_n (expld.dot, expld.result.value);
388 expld.result.valid_p = FALSE;
391 case DATA_SEGMENT_END:
392 if (expld.phase == lang_first_phase_enum
393 || expld.section != bfd_abs_section_ptr)
395 expld.result.valid_p = FALSE;
397 else if (expld.dataseg.phase == exp_dataseg_align_seen
398 || expld.dataseg.phase == exp_dataseg_relro_seen)
400 expld.dataseg.phase = exp_dataseg_end_seen;
401 expld.dataseg.end = expld.result.value;
403 else if (expld.dataseg.phase == exp_dataseg_done
404 || expld.dataseg.phase == exp_dataseg_adjust
405 || expld.dataseg.phase == exp_dataseg_relro_adjust)
410 expld.result.valid_p = FALSE;
421 fold_binary (etree_type *tree)
423 etree_value_type lhs;
424 exp_fold_tree_1 (tree->binary.lhs);
426 /* The SEGMENT_START operator is special because its first
427 operand is a string, not the name of a symbol. Note that the
428 operands have been swapped, so binary.lhs is second (default)
429 operand, binary.rhs is first operand. */
430 if (expld.result.valid_p && tree->type.node_code == SEGMENT_START)
432 const char *segment_name;
435 /* Check to see if the user has overridden the default
437 segment_name = tree->binary.rhs->name.name;
438 for (seg = segments; seg; seg = seg->next)
439 if (strcmp (seg->name, segment_name) == 0)
442 && config.magic_demand_paged
443 && (seg->value % config.maxpagesize) != 0)
444 einfo (_("%P: warning: address of `%s' isn't multiple of maximum page size\n"),
447 new_rel_from_abs (seg->value);
454 exp_fold_tree_1 (tree->binary.rhs);
455 expld.result.valid_p &= lhs.valid_p;
457 if (expld.result.valid_p)
459 if (lhs.section != expld.result.section)
461 /* If the values are from different sections, and neither is
462 just a number, make both the source arguments absolute. */
463 if (expld.result.section != NULL
464 && lhs.section != NULL)
467 lhs.value += lhs.section->vma;
468 lhs.section = bfd_abs_section_ptr;
471 /* If the rhs is just a number, keep the lhs section. */
472 else if (expld.result.section == NULL)
474 expld.result.section = lhs.section;
475 /* Make this NULL so that we know one of the operands
476 was just a number, for later tests. */
480 /* At this point we know that both operands have the same
481 section, or at least one of them is a plain number. */
483 switch (tree->type.node_code)
485 /* Arithmetic operators, bitwise AND, bitwise OR and XOR
486 keep the section of one of their operands only when the
487 other operand is a plain number. Losing the section when
488 operating on two symbols, ie. a result of a plain number,
489 is required for subtraction and XOR. It's justifiable
490 for the other operations on the grounds that adding,
491 multiplying etc. two section relative values does not
492 really make sense unless they are just treated as
494 The same argument could be made for many expressions
495 involving one symbol and a number. For example,
496 "1 << x" and "100 / x" probably should not be given the
497 section of x. The trouble is that if we fuss about such
498 things the rules become complex and it is onerous to
499 document ld expression evaluation. */
502 expld.result.value = lhs.value y expld.result.value; \
503 if (expld.result.section == lhs.section) \
504 expld.result.section = NULL; \
507 /* Comparison operators, logical AND, and logical OR always
508 return a plain number. */
511 expld.result.value = lhs.value y expld.result.value; \
512 expld.result.section = NULL; \
533 if (expld.result.value != 0)
534 expld.result.value = ((bfd_signed_vma) lhs.value
535 % (bfd_signed_vma) expld.result.value);
536 else if (expld.phase != lang_mark_phase_enum)
537 einfo (_("%F%S %% by zero\n"), tree->binary.rhs);
538 if (expld.result.section == lhs.section)
539 expld.result.section = NULL;
543 if (expld.result.value != 0)
544 expld.result.value = ((bfd_signed_vma) lhs.value
545 / (bfd_signed_vma) expld.result.value);
546 else if (expld.phase != lang_mark_phase_enum)
547 einfo (_("%F%S / by zero\n"), tree->binary.rhs);
548 if (expld.result.section == lhs.section)
549 expld.result.section = NULL;
553 if (lhs.value > expld.result.value)
554 expld.result.value = lhs.value;
558 if (lhs.value < expld.result.value)
559 expld.result.value = lhs.value;
563 expld.result.value = align_n (lhs.value, expld.result.value);
566 case DATA_SEGMENT_ALIGN:
567 expld.dataseg.relro = exp_dataseg_relro_start;
568 if (expld.phase == lang_first_phase_enum
569 || expld.section != bfd_abs_section_ptr)
570 expld.result.valid_p = FALSE;
573 bfd_vma maxpage = lhs.value;
574 bfd_vma commonpage = expld.result.value;
576 expld.result.value = align_n (expld.dot, maxpage);
577 if (expld.dataseg.phase == exp_dataseg_relro_adjust)
578 expld.result.value = expld.dataseg.base;
579 else if (expld.dataseg.phase == exp_dataseg_adjust)
581 if (commonpage < maxpage)
582 expld.result.value += ((expld.dot + commonpage - 1)
583 & (maxpage - commonpage));
587 expld.result.value += expld.dot & (maxpage - 1);
588 if (expld.dataseg.phase == exp_dataseg_done)
592 else if (expld.dataseg.phase == exp_dataseg_none)
594 expld.dataseg.phase = exp_dataseg_align_seen;
595 expld.dataseg.base = expld.result.value;
596 expld.dataseg.pagesize = commonpage;
597 expld.dataseg.maxpagesize = maxpage;
598 expld.dataseg.relro_end = 0;
601 expld.result.valid_p = FALSE;
606 case DATA_SEGMENT_RELRO_END:
607 /* Operands swapped! DATA_SEGMENT_RELRO_END(offset,exp)
608 has offset in expld.result and exp in lhs. */
609 expld.dataseg.relro = exp_dataseg_relro_end;
610 expld.dataseg.relro_offset = expld.result.value;
611 if (expld.phase == lang_first_phase_enum
612 || expld.section != bfd_abs_section_ptr)
613 expld.result.valid_p = FALSE;
614 else if (expld.dataseg.phase == exp_dataseg_align_seen
615 || expld.dataseg.phase == exp_dataseg_adjust
616 || expld.dataseg.phase == exp_dataseg_relro_adjust
617 || expld.dataseg.phase == exp_dataseg_done)
619 if (expld.dataseg.phase == exp_dataseg_align_seen
620 || expld.dataseg.phase == exp_dataseg_relro_adjust)
621 expld.dataseg.relro_end = lhs.value + expld.result.value;
623 if (expld.dataseg.phase == exp_dataseg_relro_adjust
624 && (expld.dataseg.relro_end
625 & (expld.dataseg.pagesize - 1)))
627 expld.dataseg.relro_end += expld.dataseg.pagesize - 1;
628 expld.dataseg.relro_end &= ~(expld.dataseg.pagesize - 1);
629 expld.result.value = (expld.dataseg.relro_end
630 - expld.result.value);
633 expld.result.value = lhs.value;
635 if (expld.dataseg.phase == exp_dataseg_align_seen)
636 expld.dataseg.phase = exp_dataseg_relro_seen;
639 expld.result.valid_p = FALSE;
649 fold_trinary (etree_type *tree)
651 exp_fold_tree_1 (tree->trinary.cond);
652 if (expld.result.valid_p)
653 exp_fold_tree_1 (expld.result.value
655 : tree->trinary.rhs);
659 fold_name (etree_type *tree)
661 memset (&expld.result, 0, sizeof (expld.result));
663 switch (tree->type.node_code)
666 if (expld.phase != lang_first_phase_enum)
668 bfd_vma hdr_size = 0;
669 /* Don't find the real header size if only marking sections;
670 The bfd function may cache incorrect data. */
671 if (expld.phase != lang_mark_phase_enum)
672 hdr_size = bfd_sizeof_headers (link_info.output_bfd, &link_info);
673 new_number (hdr_size);
678 if (expld.phase != lang_first_phase_enum)
680 struct bfd_link_hash_entry *h;
681 struct definedness_hash_entry *def;
683 h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
687 new_number (h != NULL
688 && (h->type == bfd_link_hash_defined
689 || h->type == bfd_link_hash_defweak
690 || h->type == bfd_link_hash_common)
691 && ((def = symbol_defined (tree->name.name)) == NULL
693 || def->iteration == (lang_statement_iteration & 1)));
698 if (expld.assign_name != NULL
699 && strcmp (expld.assign_name, tree->name.name) == 0)
701 /* Self-assignment is only allowed for absolute symbols
702 defined in a linker script. */
703 struct bfd_link_hash_entry *h;
704 struct definedness_hash_entry *def;
706 h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
711 && (h->type == bfd_link_hash_defined
712 || h->type == bfd_link_hash_defweak)
713 && h->u.def.section == bfd_abs_section_ptr
714 && (def = symbol_defined (tree->name.name)) != NULL
715 && def->iteration == (lang_statement_iteration & 1)))
716 expld.assign_name = NULL;
718 if (expld.phase == lang_first_phase_enum)
720 else if (tree->name.name[0] == '.' && tree->name.name[1] == 0)
721 new_rel_from_abs (expld.dot);
724 struct bfd_link_hash_entry *h;
726 h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
731 einfo (_("%P%F: bfd_link_hash_lookup failed: %E\n"));
732 else if (h->type == bfd_link_hash_defined
733 || h->type == bfd_link_hash_defweak)
735 asection *output_section;
737 output_section = h->u.def.section->output_section;
738 if (output_section == NULL)
740 if (expld.phase == lang_mark_phase_enum)
741 new_rel (h->u.def.value, h->u.def.section);
743 einfo (_("%X%S: unresolvable symbol `%s'"
744 " referenced in expression\n"),
745 tree, tree->name.name);
747 else if (output_section == bfd_abs_section_ptr
748 && (expld.section != bfd_abs_section_ptr
749 || config.sane_expr))
750 new_number (h->u.def.value + h->u.def.section->output_offset);
752 new_rel (h->u.def.value + h->u.def.section->output_offset,
755 else if (expld.phase == lang_final_phase_enum
756 || (expld.phase != lang_mark_phase_enum
757 && expld.assigning_to_dot))
758 einfo (_("%F%S: undefined symbol `%s'"
759 " referenced in expression\n"),
760 tree, tree->name.name);
761 else if (h->type == bfd_link_hash_new)
763 h->type = bfd_link_hash_undefined;
764 h->u.undef.abfd = NULL;
765 if (h->u.undef.next == NULL && h != link_info.hash->undefs_tail)
766 bfd_link_add_undef (link_info.hash, h);
772 if (expld.phase != lang_first_phase_enum)
774 lang_output_section_statement_type *os;
776 os = lang_output_section_find (tree->name.name);
779 if (expld.phase == lang_final_phase_enum)
780 einfo (_("%F%S: undefined section `%s'"
781 " referenced in expression\n"),
782 tree, tree->name.name);
784 else if (os->processed_vma)
785 new_rel (0, os->bfd_section);
790 if (expld.phase != lang_first_phase_enum)
792 lang_output_section_statement_type *os;
794 os = lang_output_section_find (tree->name.name);
797 if (expld.phase == lang_final_phase_enum)
798 einfo (_("%F%S: undefined section `%s'"
799 " referenced in expression\n"),
800 tree, tree->name.name);
802 else if (os->processed_lma)
804 if (os->load_base == NULL)
805 new_abs (os->bfd_section->lma);
808 exp_fold_tree_1 (os->load_base);
809 if (expld.result.valid_p)
818 if (expld.phase != lang_first_phase_enum)
820 lang_output_section_statement_type *os;
822 os = lang_output_section_find (tree->name.name);
825 if (expld.phase == lang_final_phase_enum)
826 einfo (_("%F%S: undefined section `%s'"
827 " referenced in expression\n"),
828 tree, tree->name.name);
831 else if (os->bfd_section != NULL)
835 if (tree->type.node_code == SIZEOF)
836 val = (os->bfd_section->size
837 / bfd_octets_per_byte (link_info.output_bfd));
839 val = (bfd_vma)1 << os->bfd_section->alignment_power;
850 if (expld.phase != lang_first_phase_enum)
852 lang_memory_region_type *mem;
854 mem = lang_memory_region_lookup (tree->name.name, FALSE);
856 new_number (mem->length);
858 einfo (_("%F%S: undefined MEMORY region `%s'"
859 " referenced in expression\n"),
860 tree, tree->name.name);
866 if (expld.phase != lang_first_phase_enum)
868 lang_memory_region_type *mem;
870 mem = lang_memory_region_lookup (tree->name.name, FALSE);
872 new_rel_from_abs (mem->origin);
874 einfo (_("%F%S: undefined MEMORY region `%s'"
875 " referenced in expression\n"),
876 tree, tree->name.name);
881 if (strcmp (tree->name.name, "MAXPAGESIZE") == 0)
882 new_number (config.maxpagesize);
883 else if (strcmp (tree->name.name, "COMMONPAGESIZE") == 0)
884 new_number (config.commonpagesize);
886 einfo (_("%F%S: unknown constant `%s' referenced in expression\n"),
887 tree, tree->name.name);
896 /* Return true if TREE is '.'. */
899 is_dot (const etree_type *tree)
901 return (tree->type.node_class == etree_name
902 && tree->type.node_code == NAME
903 && tree->name.name[0] == '.'
904 && tree->name.name[1] == 0);
907 /* Return true if TREE is a constant equal to VAL. */
910 is_value (const etree_type *tree, bfd_vma val)
912 return (tree->type.node_class == etree_value
913 && tree->value.value == val);
916 /* Return true if TREE is an absolute symbol equal to VAL defined in
920 is_sym_value (const etree_type *tree, bfd_vma val)
922 struct bfd_link_hash_entry *h;
923 struct definedness_hash_entry *def;
925 return (tree->type.node_class == etree_name
926 && tree->type.node_code == NAME
927 && (def = symbol_defined (tree->name.name)) != NULL
929 && def->iteration == (lang_statement_iteration & 1)
930 && (h = bfd_wrapped_link_hash_lookup (link_info.output_bfd,
933 FALSE, FALSE, TRUE)) != NULL
934 && h->type == bfd_link_hash_defined
935 && h->u.def.section == bfd_abs_section_ptr
936 && h->u.def.value == val);
939 /* Return true if TREE is ". != 0". */
942 is_dot_ne_0 (const etree_type *tree)
944 return (tree->type.node_class == etree_binary
945 && tree->type.node_code == NE
946 && is_dot (tree->binary.lhs)
947 && is_value (tree->binary.rhs, 0));
950 /* Return true if TREE is ". = . + 0" or ". = . + sym" where sym is an
951 absolute constant with value 0 defined in a linker script. */
954 is_dot_plus_0 (const etree_type *tree)
956 return (tree->type.node_class == etree_binary
957 && tree->type.node_code == '+'
958 && is_dot (tree->binary.lhs)
959 && (is_value (tree->binary.rhs, 0)
960 || is_sym_value (tree->binary.rhs, 0)));
963 /* Return true if TREE is "ALIGN (. != 0 ? some_expression : 1)". */
966 is_align_conditional (const etree_type *tree)
968 if (tree->type.node_class == etree_unary
969 && tree->type.node_code == ALIGN_K)
971 tree = tree->unary.child;
972 return (tree->type.node_class == etree_trinary
973 && is_dot_ne_0 (tree->trinary.cond)
974 && is_value (tree->trinary.rhs, 1));
979 /* Subroutine of exp_fold_tree_1 for copying a symbol type. */
982 try_copy_symbol_type (struct bfd_link_hash_entry * h, etree_type *src)
984 if (src->type.node_class == etree_name)
986 struct bfd_link_hash_entry *hsrc;
988 hsrc = bfd_link_hash_lookup (link_info.hash, src->name.name,
991 bfd_copy_link_hash_symbol_type (link_info.output_bfd, h,
997 exp_fold_tree_1 (etree_type *tree)
1001 memset (&expld.result, 0, sizeof (expld.result));
1005 switch (tree->type.node_class)
1008 if (expld.section == bfd_abs_section_ptr
1009 && !config.sane_expr)
1010 new_abs (tree->value.value);
1012 new_number (tree->value.value);
1013 expld.result.str = tree->value.str;
1017 if (expld.phase != lang_first_phase_enum)
1019 asection *output_section = tree->rel.section->output_section;
1020 new_rel (tree->rel.value + tree->rel.section->output_offset,
1024 memset (&expld.result, 0, sizeof (expld.result));
1028 exp_fold_tree_1 (tree->assert_s.child);
1029 if (expld.phase == lang_final_phase_enum && !expld.result.value)
1030 einfo ("%X%P: %s\n", tree->assert_s.message);
1042 fold_trinary (tree);
1047 case etree_provided:
1048 if (tree->assign.dst[0] == '.' && tree->assign.dst[1] == 0)
1050 if (tree->type.node_class != etree_assign)
1051 einfo (_("%F%S can not PROVIDE assignment to"
1052 " location counter\n"), tree);
1053 if (expld.phase != lang_first_phase_enum)
1055 /* Notify the folder that this is an assignment to dot. */
1056 expld.assigning_to_dot = TRUE;
1057 exp_fold_tree_1 (tree->assign.src);
1058 expld.assigning_to_dot = FALSE;
1060 /* If we are assigning to dot inside an output section
1061 arrange to keep the section, except for certain
1062 expressions that evaluate to zero. We ignore . = 0,
1063 . = . + 0, and . = ALIGN (. != 0 ? expr : 1).
1064 We can't ignore all expressions that evaluate to zero
1065 because an otherwise empty section might have padding
1066 added by an alignment expression that changes with
1067 relaxation. Such a section might have zero size
1068 before relaxation and so be stripped incorrectly. */
1069 if (expld.phase == lang_mark_phase_enum
1070 && expld.section != bfd_abs_section_ptr
1071 && !(expld.result.valid_p
1072 && expld.result.value == 0
1073 && (is_value (tree->assign.src, 0)
1074 || is_sym_value (tree->assign.src, 0)
1075 || is_dot_plus_0 (tree->assign.src)
1076 || is_align_conditional (tree->assign.src))))
1077 expld.section->flags |= SEC_KEEP;
1079 if (!expld.result.valid_p)
1081 if (expld.phase != lang_mark_phase_enum)
1082 einfo (_("%F%S invalid assignment to"
1083 " location counter\n"), tree);
1085 else if (expld.dotp == NULL)
1086 einfo (_("%F%S assignment to location counter"
1087 " invalid outside of SECTIONS\n"), tree);
1089 /* After allocation, assignment to dot should not be
1090 done inside an output section since allocation adds a
1091 padding statement that effectively duplicates the
1093 else if (expld.phase <= lang_allocating_phase_enum
1094 || expld.section == bfd_abs_section_ptr)
1098 nextdot = expld.result.value;
1099 if (expld.result.section != NULL)
1100 nextdot += expld.result.section->vma;
1102 nextdot += expld.section->vma;
1103 if (nextdot < expld.dot
1104 && expld.section != bfd_abs_section_ptr)
1105 einfo (_("%F%S cannot move location counter backwards"
1106 " (from %V to %V)\n"),
1107 tree, expld.dot, nextdot);
1110 expld.dot = nextdot;
1111 *expld.dotp = nextdot;
1116 memset (&expld.result, 0, sizeof (expld.result));
1120 struct bfd_link_hash_entry *h = NULL;
1122 if (tree->type.node_class == etree_provide)
1124 h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst,
1125 FALSE, FALSE, TRUE);
1127 || !(h->type == bfd_link_hash_new
1128 || h->type == bfd_link_hash_undefined
1129 || h->type == bfd_link_hash_undefweak
1132 /* Do nothing. The symbol was never referenced, or
1133 was defined in some object file. Note that
1134 undefweak symbols are defined by PROVIDE. This
1135 is to support glibc use of __rela_iplt_start and
1136 similar weak references. */
1141 expld.assign_name = tree->assign.dst;
1142 exp_fold_tree_1 (tree->assign.src);
1143 /* expld.assign_name remaining equal to tree->assign.dst
1144 below indicates the evaluation of tree->assign.src did
1145 not use the value of tree->assign.dst. We don't allow
1146 self assignment until the final phase for two reasons:
1147 1) Expressions are evaluated multiple times. With
1148 relaxation, the number of times may vary.
1149 2) Section relative symbol values cannot be correctly
1150 converted to absolute values, as is required by many
1151 expressions, until final section sizing is complete. */
1152 if ((expld.result.valid_p
1153 && (expld.phase == lang_final_phase_enum
1154 || expld.assign_name != NULL))
1155 || (expld.phase <= lang_mark_phase_enum
1156 && tree->type.node_class == etree_assign
1157 && tree->assign.defsym))
1161 h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst,
1164 einfo (_("%P%F:%s: hash creation failed\n"),
1168 if (expld.result.section == NULL)
1169 expld.result.section = expld.section;
1170 if (!update_definedness (tree->assign.dst, h) && 0)
1172 /* Symbol was already defined. For now this error
1173 is disabled because it causes failures in the ld
1174 testsuite: ld-elf/var1, ld-scripts/defined5, and
1175 ld-scripts/pr14962. Some of these no doubt
1176 reflect scripts used in the wild. */
1177 (*link_info.callbacks->multiple_definition)
1178 (&link_info, h, link_info.output_bfd,
1179 expld.result.section, expld.result.value);
1181 h->type = bfd_link_hash_defined;
1182 h->u.def.value = expld.result.value;
1183 h->u.def.section = expld.result.section;
1185 if (tree->type.node_class == etree_provide)
1186 tree->type.node_class = etree_provided;
1188 /* Copy the symbol type if this is a simple assignment of
1189 one symbol to another. Also, handle the case of a foldable
1190 ternary conditional with names on either side. */
1191 if (tree->assign.src->type.node_class == etree_name)
1192 try_copy_symbol_type (h, tree->assign.src);
1193 else if (tree->assign.src->type.node_class == etree_trinary)
1195 exp_fold_tree_1 (tree->assign.src->trinary.cond);
1196 if (expld.result.valid_p)
1198 if (expld.result.value
1199 && tree->assign.src->trinary.lhs->type.node_class
1201 try_copy_symbol_type (h, tree->assign.src->trinary.lhs);
1203 if (!expld.result.value
1204 && tree->assign.src->trinary.rhs->type.node_class
1206 try_copy_symbol_type (h, tree->assign.src->trinary.rhs);
1210 else if (expld.phase == lang_final_phase_enum)
1212 h = bfd_link_hash_lookup (link_info.hash, tree->assign.dst,
1213 FALSE, FALSE, TRUE);
1215 && h->type == bfd_link_hash_new)
1216 h->type = bfd_link_hash_undefined;
1218 expld.assign_name = NULL;
1228 memset (&expld.result, 0, sizeof (expld.result));
1234 exp_fold_tree (etree_type *tree, asection *current_section, bfd_vma *dotp)
1236 expld.rel_from_abs = FALSE;
1239 expld.section = current_section;
1240 exp_fold_tree_1 (tree);
1244 exp_fold_tree_no_dot (etree_type *tree)
1246 expld.rel_from_abs = FALSE;
1249 expld.section = bfd_abs_section_ptr;
1250 exp_fold_tree_1 (tree);
1254 exp_binop (int code, etree_type *lhs, etree_type *rhs)
1256 etree_type value, *new_e;
1258 value.type.node_code = code;
1259 value.type.filename = lhs->type.filename;
1260 value.type.lineno = lhs->type.lineno;
1261 value.binary.lhs = lhs;
1262 value.binary.rhs = rhs;
1263 value.type.node_class = etree_binary;
1264 exp_fold_tree_no_dot (&value);
1265 if (expld.result.valid_p)
1266 return exp_intop (expld.result.value);
1268 new_e = (etree_type *) stat_alloc (sizeof (new_e->binary));
1269 memcpy (new_e, &value, sizeof (new_e->binary));
1274 exp_trinop (int code, etree_type *cond, etree_type *lhs, etree_type *rhs)
1276 etree_type value, *new_e;
1278 value.type.node_code = code;
1279 value.type.filename = cond->type.filename;
1280 value.type.lineno = cond->type.lineno;
1281 value.trinary.lhs = lhs;
1282 value.trinary.cond = cond;
1283 value.trinary.rhs = rhs;
1284 value.type.node_class = etree_trinary;
1285 exp_fold_tree_no_dot (&value);
1286 if (expld.result.valid_p)
1287 return exp_intop (expld.result.value);
1289 new_e = (etree_type *) stat_alloc (sizeof (new_e->trinary));
1290 memcpy (new_e, &value, sizeof (new_e->trinary));
1295 exp_unop (int code, etree_type *child)
1297 etree_type value, *new_e;
1299 value.unary.type.node_code = code;
1300 value.unary.type.filename = child->type.filename;
1301 value.unary.type.lineno = child->type.lineno;
1302 value.unary.child = child;
1303 value.unary.type.node_class = etree_unary;
1304 exp_fold_tree_no_dot (&value);
1305 if (expld.result.valid_p)
1306 return exp_intop (expld.result.value);
1308 new_e = (etree_type *) stat_alloc (sizeof (new_e->unary));
1309 memcpy (new_e, &value, sizeof (new_e->unary));
1314 exp_nameop (int code, const char *name)
1316 etree_type value, *new_e;
1318 value.name.type.node_code = code;
1319 value.name.type.filename = ldlex_filename ();
1320 value.name.type.lineno = lineno;
1321 value.name.name = name;
1322 value.name.type.node_class = etree_name;
1324 exp_fold_tree_no_dot (&value);
1325 if (expld.result.valid_p)
1326 return exp_intop (expld.result.value);
1328 new_e = (etree_type *) stat_alloc (sizeof (new_e->name));
1329 memcpy (new_e, &value, sizeof (new_e->name));
1335 exp_assop (const char *dst,
1337 enum node_tree_enum class,
1343 n = (etree_type *) stat_alloc (sizeof (n->assign));
1344 n->assign.type.node_code = '=';
1345 n->assign.type.filename = src->type.filename;
1346 n->assign.type.lineno = src->type.lineno;
1347 n->assign.type.node_class = class;
1348 n->assign.src = src;
1349 n->assign.dst = dst;
1350 n->assign.defsym = defsym;
1351 n->assign.hidden = hidden;
1355 /* Handle linker script assignments and HIDDEN. */
1358 exp_assign (const char *dst, etree_type *src, bfd_boolean hidden)
1360 return exp_assop (dst, src, etree_assign, FALSE, hidden);
1363 /* Handle --defsym command-line option. */
1366 exp_defsym (const char *dst, etree_type *src)
1368 return exp_assop (dst, src, etree_assign, TRUE, FALSE);
1371 /* Handle PROVIDE. */
1374 exp_provide (const char *dst, etree_type *src, bfd_boolean hidden)
1376 return exp_assop (dst, src, etree_provide, FALSE, hidden);
1379 /* Handle ASSERT. */
1382 exp_assert (etree_type *exp, const char *message)
1386 n = (etree_type *) stat_alloc (sizeof (n->assert_s));
1387 n->assert_s.type.node_code = '!';
1388 n->assert_s.type.filename = exp->type.filename;
1389 n->assert_s.type.lineno = exp->type.lineno;
1390 n->assert_s.type.node_class = etree_assert;
1391 n->assert_s.child = exp;
1392 n->assert_s.message = message;
1397 exp_print_tree (etree_type *tree)
1399 bfd_boolean function_like;
1401 if (config.map_file == NULL)
1402 config.map_file = stderr;
1406 minfo ("NULL TREE\n");
1410 switch (tree->type.node_class)
1413 minfo ("0x%v", tree->value.value);
1416 if (tree->rel.section->owner != NULL)
1417 minfo ("%B:", tree->rel.section->owner);
1418 minfo ("%s+0x%v", tree->rel.section->name, tree->rel.value);
1421 fputs (tree->assign.dst, config.map_file);
1422 exp_print_token (tree->type.node_code, TRUE);
1423 exp_print_tree (tree->assign.src);
1426 case etree_provided:
1427 fprintf (config.map_file, "PROVIDE (%s, ", tree->assign.dst);
1428 exp_print_tree (tree->assign.src);
1429 fputc (')', config.map_file);
1432 function_like = FALSE;
1433 switch (tree->type.node_code)
1438 case DATA_SEGMENT_ALIGN:
1439 case DATA_SEGMENT_RELRO_END:
1440 function_like = TRUE;
1443 /* Special handling because arguments are in reverse order and
1444 the segment name is quoted. */
1445 exp_print_token (tree->type.node_code, FALSE);
1446 fputs (" (\"", config.map_file);
1447 exp_print_tree (tree->binary.rhs);
1448 fputs ("\", ", config.map_file);
1449 exp_print_tree (tree->binary.lhs);
1450 fputc (')', config.map_file);
1455 exp_print_token (tree->type.node_code, FALSE);
1456 fputc (' ', config.map_file);
1458 fputc ('(', config.map_file);
1459 exp_print_tree (tree->binary.lhs);
1461 fprintf (config.map_file, ", ");
1463 exp_print_token (tree->type.node_code, TRUE);
1464 exp_print_tree (tree->binary.rhs);
1465 fputc (')', config.map_file);
1468 exp_print_tree (tree->trinary.cond);
1469 fputc ('?', config.map_file);
1470 exp_print_tree (tree->trinary.lhs);
1471 fputc (':', config.map_file);
1472 exp_print_tree (tree->trinary.rhs);
1475 exp_print_token (tree->unary.type.node_code, FALSE);
1476 if (tree->unary.child)
1478 fprintf (config.map_file, " (");
1479 exp_print_tree (tree->unary.child);
1480 fputc (')', config.map_file);
1485 fprintf (config.map_file, "ASSERT (");
1486 exp_print_tree (tree->assert_s.child);
1487 fprintf (config.map_file, ", %s)", tree->assert_s.message);
1491 if (tree->type.node_code == NAME)
1492 fputs (tree->name.name, config.map_file);
1495 exp_print_token (tree->type.node_code, FALSE);
1496 if (tree->name.name)
1497 fprintf (config.map_file, " (%s)", tree->name.name);
1507 exp_get_vma (etree_type *tree, bfd_vma def, char *name)
1511 exp_fold_tree_no_dot (tree);
1512 if (expld.result.valid_p)
1513 return expld.result.value;
1514 else if (name != NULL && expld.phase != lang_mark_phase_enum)
1515 einfo (_("%F%S: nonconstant expression for %s\n"),
1522 exp_get_value_int (etree_type *tree, int def, char *name)
1524 return exp_get_vma (tree, def, name);
1528 exp_get_fill (etree_type *tree, fill_type *def, char *name)
1537 exp_fold_tree_no_dot (tree);
1538 if (!expld.result.valid_p)
1540 if (name != NULL && expld.phase != lang_mark_phase_enum)
1541 einfo (_("%F%S: nonconstant expression for %s\n"),
1546 if (expld.result.str != NULL && (len = strlen (expld.result.str)) != 0)
1550 fill = (fill_type *) xmalloc ((len + 1) / 2 + sizeof (*fill) - 1);
1551 fill->size = (len + 1) / 2;
1553 s = (unsigned char *) expld.result.str;
1561 digit = (digit - 'A' + '0' + 10) & 0xf;
1575 fill = (fill_type *) xmalloc (4 + sizeof (*fill) - 1);
1576 val = expld.result.value;
1577 fill->data[0] = (val >> 24) & 0xff;
1578 fill->data[1] = (val >> 16) & 0xff;
1579 fill->data[2] = (val >> 8) & 0xff;
1580 fill->data[3] = (val >> 0) & 0xff;
1587 exp_get_abs_int (etree_type *tree, int def, char *name)
1591 exp_fold_tree_no_dot (tree);
1593 if (expld.result.valid_p)
1595 if (expld.result.section != NULL)
1596 expld.result.value += expld.result.section->vma;
1597 return expld.result.value;
1599 else if (name != NULL && expld.phase != lang_mark_phase_enum)
1601 einfo (_("%F%S: nonconstant expression for %s\n"),
1609 align_n (bfd_vma value, bfd_vma align)
1614 value = (value + align - 1) / align;
1615 return value * align;
1621 /* The value "13" is ad-hoc, somewhat related to the expected number of
1622 assignments in a linker script. */
1623 if (!bfd_hash_table_init_n (&definedness_table,
1624 definedness_newfunc,
1625 sizeof (struct definedness_hash_entry),
1627 einfo (_("%P%F: can not create hash table: %E\n"));
1630 /* Convert absolute symbols defined by a script from "dot" (also
1631 SEGMENT_START or ORIGIN) outside of an output section statement,
1632 to section relative. */
1635 set_sym_sections (struct bfd_hash_entry *bh, void *inf ATTRIBUTE_UNUSED)
1637 struct definedness_hash_entry *def = (struct definedness_hash_entry *) bh;
1638 if (def->final_sec != bfd_abs_section_ptr)
1640 struct bfd_link_hash_entry *h;
1641 h = bfd_link_hash_lookup (link_info.hash, bh->string,
1642 FALSE, FALSE, TRUE);
1644 && h->type == bfd_link_hash_defined
1645 && h->u.def.section == bfd_abs_section_ptr)
1647 h->u.def.value -= def->final_sec->vma;
1648 h->u.def.section = def->final_sec;
1655 ldexp_finalize_syms (void)
1657 bfd_hash_traverse (&definedness_table, set_sym_sections, NULL);
1663 bfd_hash_table_free (&definedness_table);