1 /* ldexp.h -
2 Copyright (C) 1991-2023 Free Software Foundation, Inc.
3
4 This file is part of the GNU Binutils.
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
19 MA 02110-1301, USA. */
20
21 #ifndef LDEXP_H
22 #define LDEXP_H
23
24 /* The result of an expression tree */
25 typedef struct {
26 bfd_vma value;
27 char *str;
28 asection *section;
29 bool valid_p;
30 } etree_value_type;
31
32 enum node_tree_enum {
33 etree_binary,
34 etree_trinary,
35 etree_unary,
36 etree_name,
37 etree_assign,
38 etree_provide,
39 etree_provided,
40 etree_value,
41 etree_assert,
42 etree_rel
43 };
44
45 typedef struct {
46 int node_code;
47 unsigned int lineno;
48 const char *filename;
49 enum node_tree_enum node_class;
50 } node_type;
51
52 typedef union etree_union {
53 node_type type;
54 struct {
55 node_type type;
56 union etree_union *lhs;
57 union etree_union *rhs;
58 } binary;
59 struct {
60 node_type type;
61 union etree_union *cond;
62 union etree_union *lhs;
63 union etree_union *rhs;
64 } trinary;
65 struct {
66 node_type type;
67 const char *dst;
68 union etree_union *src;
69 bool hidden;
70 } assign;
71 struct {
72 node_type type;
73 union etree_union *child;
74 } unary;
75 struct {
76 node_type type;
77 const char *name;
78 } name;
79 struct {
80 node_type type;
81 bfd_vma value;
82 char *str;
83 } value;
84 struct {
85 node_type type;
86 asection *section;
87 bfd_vma value;
88 } rel;
89 struct {
90 node_type type;
91 union etree_union *child;
92 const char *message;
93 } assert_s;
94 } etree_type;
95
96 /* Expression evaluation control. */
97 typedef enum
98 {
99 /* Parsing linker script. Will only return "valid" for expressions
100 that evaluate to a constant. */
101 lang_first_phase_enum,
102 /* Prior to section sizing. */
103 lang_mark_phase_enum,
104 /* During section sizing. */
105 lang_allocating_phase_enum,
106 /* During assignment of symbol values when relaxation in progress. */
107 lang_assigning_phase_enum,
108 /* Final assignment of symbol values. */
109 lang_final_phase_enum,
110 /* Run after symbol values have been fixed, for lang_map. */
111 lang_fixed_phase_enum
112 } lang_phase_type;
113
114 union lang_statement_union;
115
116 enum phase_enum {
117 /* We step through the first four states here as we see the
118 associated linker script tokens. */
119 exp_seg_none,
120 exp_seg_align_seen,
121 exp_seg_relro_seen,
122 exp_seg_end_seen,
123 /* The last three states are final, and affect the value returned
124 by XXX_SEGMENT_ALIGN. */
125 exp_seg_relro_adjust,
126 exp_seg_adjust,
127 exp_seg_done
128 };
129
130 enum relro_enum {
131 exp_seg_relro_none,
132 exp_seg_relro_start,
133 exp_seg_relro_end,
134 };
135
136 typedef struct {
137 enum phase_enum phase;
138
139 bfd_vma base, relro_offset, relro_end, end;
140 /* MAXPAGESIZE and COMMMONPAGESIZE as passed to DATA_SEGMENT_ALIGN.
141 relropagesize sets the alignment of the end of the relro segment. */
142 bfd_vma maxpagesize, commonpagesize, relropagesize;
143
144 enum relro_enum relro;
145
146 union lang_statement_union *relro_start_stat;
147 union lang_statement_union *relro_end_stat;
148 } seg_align_type;
149
150 struct ldexp_control {
151 /* Modify expression evaluation depending on this. */
152 lang_phase_type phase;
153
154 /* Principally used for diagnostics. */
155 bool assigning_to_dot;
156
157 /* Set if the current expression used "dot", SEGMENT_START or
158 ORIGIN, but not ABSOLUTE or combined symbols in a way that forces
159 an absolute result. Used in tracking symbols assigned from dot
160 outside of output section statements, in order to later convert
161 them from absolute. */
162 bool rel_from_abs;
163
164 /* If evaluating an assignment, the destination. Cleared if an
165 etree_name NAME matches this, to signal a self-assignment.
166 Note that an etree_name DEFINED does not clear this field, nor
167 does the false branch of a trinary expression. */
168 const char *assign_name;
169
170 /* If evaluating an assignment, the source if it is an expression
171 referencing single etree_name NAME, or a trinary expression where
172 the true branch references a single etree_name NAME. */
173 struct bfd_link_hash_entry *assign_src;
174
175 /* Working results. */
176 etree_value_type result;
177 bfd_vma dot;
178
179 /* Current dot and section passed to ldexp folder. */
180 bfd_vma *dotp;
181 asection *section;
182
183 /* State machine and results for DATASEG. */
184 seg_align_type dataseg;
185 };
186
187 extern struct ldexp_control expld;
188
189 /* A maps from a segment name to a base address. */
190 typedef struct segment_struct {
191 /* The next segment in the linked list. */
192 struct segment_struct *next;
193 /* The name of the sgement. */
194 const char *name;
195 /* The base address for the segment. */
196 bfd_vma value;
197 /* True if a SEGMENT_START directive corresponding to this segment
198 has been seen. */
199 bool used;
200 } segment_type;
201
202 /* The segments specified by the user on the command-line. */
203 extern segment_type *segments;
204
205 typedef struct _fill_type fill_type;
206
207 etree_type *exp_intop
208 (bfd_vma);
209 etree_type *exp_bigintop
210 (bfd_vma, char *);
211 etree_type *exp_relop
212 (asection *, bfd_vma);
213 void exp_fold_tree
214 (etree_type *, asection *, bfd_vma *);
215 void exp_fold_tree_no_dot
216 (etree_type *);
217 etree_type *exp_binop
218 (int, etree_type *, etree_type *);
219 etree_type *exp_trinop
220 (int,etree_type *, etree_type *, etree_type *);
221 etree_type *exp_unop
222 (int, etree_type *);
223 etree_type *exp_nameop
224 (int, const char *);
225 etree_type *exp_assign
226 (const char *, etree_type *, bool);
227 etree_type *exp_defsym
228 (const char *, etree_type *);
229 etree_type *exp_provide
230 (const char *, etree_type *, bool);
231 etree_type *exp_assert
232 (etree_type *, const char *);
233 void exp_print_tree
234 (etree_type *);
235 bfd_vma exp_get_vma
236 (etree_type *, bfd_vma, char *);
237 int exp_get_power
238 (etree_type *, char *);
239 fill_type *exp_get_fill
240 (etree_type *, fill_type *, char *);
241 bfd_vma exp_get_abs_int
242 (etree_type *, int, char *);
243 void ldexp_init (void);
244 void ldexp_finalize_syms (void);
245 bool ldexp_is_final_sym_absolute (const struct bfd_link_hash_entry *);
246 void ldexp_finish (void);
247
248 #endif