aboutsummaryrefslogtreecommitdiff
path: root/ld/ldexp.h
blob: 7c302753192fdce24ec72d660909e24fe4f15fa1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
/* ldexp.h -
   Copyright (C) 1991-2023 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;
  bool 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;
    bool 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,
  /* Run after symbol values have been fixed, for lang_map.  */
  lang_fixed_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_seg_none,
  exp_seg_align_seen,
  exp_seg_relro_seen,
  exp_seg_end_seen,
  /* The last three states are final, and affect the value returned
     by XXX_SEGMENT_ALIGN.  */
  exp_seg_relro_adjust,
  exp_seg_adjust,
  exp_seg_done
};

enum relro_enum {
  exp_seg_relro_none,
  exp_seg_relro_start,
  exp_seg_relro_end,
};

struct lang_output_section_statement_struct;

typedef struct {
  enum phase_enum phase;

  bfd_vma base, relro_offset, relro_end, end;
  /* MAXPAGESIZE and COMMMONPAGESIZE as passed to DATA_SEGMENT_ALIGN.
     relropagesize sets the alignment of the end of the relro segment.  */
  bfd_vma maxpagesize, commonpagesize, relropagesize;

  enum relro_enum relro;

  union lang_statement_union *relro_start_stat;
  union lang_statement_union *relro_end_stat;
} seg_align_type;

struct ldexp_control {
  /* Modify expression evaluation depending on this.  */
  lang_phase_type phase;

  /* Principally used for diagnostics.  */
  bool 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.  */
  bool 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;

  /* If evaluating an assignment, the source if it is an expression
     referencing single etree_name NAME, or a trinary expression where
     the true branch references a single etree_name NAME.  */
  struct bfd_link_hash_entry *assign_src;

  /* Working results.  */
  etree_value_type result;
  bfd_vma dot;

  /* Current dot and section passed to ldexp folder.  SECTION will be
     bfd_abs_section for expressions outside of an output section
     statement.  */
  bfd_vma *dotp;
  asection *section;

  /* Last output section statement.  For expressions within an output
     section statement, this will be the current output section
     statement being processed.  */
  struct lang_output_section_statement_struct *last_os;

  /* State machine and results for DATASEG.  */
  seg_align_type 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.  */
  bool 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 *, struct lang_output_section_statement_struct *,
   asection *, bfd_vma *);
void exp_fold_tree_no_dot
  (etree_type *, struct lang_output_section_statement_struct *);
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 *, bool);
etree_type *exp_defsym
  (const char *, etree_type *);
etree_type *exp_provide
  (const char *, etree_type *, bool);
etree_type *exp_assert
  (etree_type *, const char *);
void exp_print_tree
  (etree_type *);
bfd_vma exp_get_vma
  (etree_type *, struct lang_output_section_statement_struct *, bfd_vma, char *);
int exp_get_power
  (etree_type *, struct lang_output_section_statement_struct *, 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);
bool ldexp_is_final_sym_absolute (const struct bfd_link_hash_entry *);
void ldexp_finish (void);

#endif