old-cross-binutils/ld/ldexp.h
Alan Modra 975f8a9e31 Delay converting linker script defined symbols from absolute
Giving linker script symbols defined outside of output sections a
section-relative value early, leads to them being used in expressions
as if they were defined inside an output section.  This can mean loss
of the section VMA, and wrong results.

ld/
	PR ld/18963
	* ldexp.h (struct ldexp_control): Add rel_from_abs.
	(ldexp_finalize_syms): Declare.
	* ldexp.c (new_rel_from_abs): Keep absolute for expressions
	outside of output section statements.  Set rel_from_abs.
	(make_abs, exp_fold_tree, exp_fold_tree_no_dot): Clear rel_from_abs.
	(struct definedness_hash_entry): Add final_sec, and comment.
	(update_definedness): Set final_sec.
	(set_sym_sections, ldexp_finalize_syms): New functions.
	* ldlang.c (lang_process): Call ldexp_finalize_syms.
ld/testsuite
	PR ld/18963
	* ld-scripts/pr18963.d,
	* ld-scripts/pr18963.t: New test.
	* ld-scripts/expr.exp: Run it.
	* ld-elf/provide-hidden-2.ld: Explicitly make "dot" absolute.
	* ld-mips-elf/gp-hidden.sd: Don't care about _gp section.
	* ld-mips-elf/no-shared-1-n32.d: Don't care about symbol shown at
	start of .data section.
	* ld-mips-elf/no-shared-1-n64.d: Likewise.
	* ld-mips-elf/no-shared-1-o32.d: Likewise.
2015-09-18 12:39:16 +09:30

236 lines
5.9 KiB
C

/* ldexp.h -
Copyright (C) 1991-2015 Free Software Foundation, Inc.
This file is part of the GNU Binutils.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#ifndef LDEXP_H
#define LDEXP_H
/* The result of an expression tree */
typedef struct {
bfd_vma value;
char *str;
asection *section;
bfd_boolean valid_p;
} etree_value_type;
enum node_tree_enum {
etree_binary,
etree_trinary,
etree_unary,
etree_name,
etree_assign,
etree_provide,
etree_provided,
etree_value,
etree_assert,
etree_rel
};
typedef struct {
int node_code;
unsigned int lineno;
const char *filename;
enum node_tree_enum node_class;
} node_type;
typedef union etree_union {
node_type type;
struct {
node_type type;
union etree_union *lhs;
union etree_union *rhs;
} binary;
struct {
node_type type;
union etree_union *cond;
union etree_union *lhs;
union etree_union *rhs;
} trinary;
struct {
node_type type;
const char *dst;
union etree_union *src;
bfd_boolean defsym;
bfd_boolean hidden;
} assign;
struct {
node_type type;
union etree_union *child;
} unary;
struct {
node_type type;
const char *name;
} name;
struct {
node_type type;
bfd_vma value;
char *str;
} value;
struct {
node_type type;
asection *section;
bfd_vma value;
} rel;
struct {
node_type type;
union etree_union *child;
const char *message;
} assert_s;
} etree_type;
/* Expression evaluation control. */
typedef enum
{
/* Parsing linker script. Will only return "valid" for expressions
that evaluate to a constant. */
lang_first_phase_enum,
/* Prior to section sizing. */
lang_mark_phase_enum,
/* During section sizing. */
lang_allocating_phase_enum,
/* During assignment of symbol values when relaxation in progress. */
lang_assigning_phase_enum,
/* Final assignment of symbol values. */
lang_final_phase_enum
} lang_phase_type;
union lang_statement_union;
enum phase_enum {
/* We step through the first four states here as we see the
associated linker script tokens. */
exp_dataseg_none,
exp_dataseg_align_seen,
exp_dataseg_relro_seen,
exp_dataseg_end_seen,
/* The last three states are final, and affect the value returned
by DATA_SEGMENT_ALIGN. */
exp_dataseg_relro_adjust,
exp_dataseg_adjust,
exp_dataseg_done
};
enum relro_enum {
exp_dataseg_relro_none,
exp_dataseg_relro_start,
exp_dataseg_relro_end,
};
struct ldexp_control {
/* Modify expression evaluation depending on this. */
lang_phase_type phase;
/* Principally used for diagnostics. */
bfd_boolean assigning_to_dot;
/* Set if the current expression used "dot", SEGMENT_START or
ORIGIN, but not ABSOLUTE or combined symbols in a way that forces
an absolute result. Used in tracking symbols assigned from dot
outside of output section statements, in order to later convert
them from absolute. */
bfd_boolean rel_from_abs;
/* If evaluating an assignment, the destination. Cleared if an
etree_name NAME matches this, to signal a self-assignment.
Note that an etree_name DEFINED does not clear this field, nor
does the false branch of a trinary expression. */
const char *assign_name;
/* Working results. */
etree_value_type result;
bfd_vma dot;
/* Current dot and section passed to ldexp folder. */
bfd_vma *dotp;
asection *section;
/* State machine and results for DATASEG. */
struct {
enum phase_enum phase;
bfd_vma base, relro_offset, relro_end, end, pagesize, maxpagesize;
enum relro_enum relro;
union lang_statement_union *relro_start_stat;
union lang_statement_union *relro_end_stat;
} dataseg;
};
extern struct ldexp_control expld;
/* A maps from a segment name to a base address. */
typedef struct segment_struct {
/* The next segment in the linked list. */
struct segment_struct *next;
/* The name of the sgement. */
const char *name;
/* The base address for the segment. */
bfd_vma value;
/* True if a SEGMENT_START directive corresponding to this segment
has been seen. */
bfd_boolean used;
} segment_type;
/* The segments specified by the user on the command-line. */
extern segment_type *segments;
typedef struct _fill_type fill_type;
etree_type *exp_intop
(bfd_vma);
etree_type *exp_bigintop
(bfd_vma, char *);
etree_type *exp_relop
(asection *, bfd_vma);
void exp_fold_tree
(etree_type *, asection *, bfd_vma *);
void exp_fold_tree_no_dot
(etree_type *);
etree_type *exp_binop
(int, etree_type *, etree_type *);
etree_type *exp_trinop
(int,etree_type *, etree_type *, etree_type *);
etree_type *exp_unop
(int, etree_type *);
etree_type *exp_nameop
(int, const char *);
etree_type *exp_assign
(const char *, etree_type *, bfd_boolean);
etree_type *exp_defsym
(const char *, etree_type *);
etree_type *exp_provide
(const char *, etree_type *, bfd_boolean);
etree_type *exp_assert
(etree_type *, const char *);
void exp_print_tree
(etree_type *);
bfd_vma exp_get_vma
(etree_type *, bfd_vma, char *);
int exp_get_value_int
(etree_type *, int, char *);
fill_type *exp_get_fill
(etree_type *, fill_type *, char *);
bfd_vma exp_get_abs_int
(etree_type *, int, char *);
void ldexp_init (void);
void ldexp_finalize_syms (void);
void ldexp_finish (void);
#endif