ld/ldexp.h

   1 /* ldexp.h -
   2    Copyright (C) 1991-2018 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   bfd_boolean 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     bfd_boolean defsym;
  70     bfd_boolean hidden;
  71   } assign;
  72   struct {
  73     node_type type;
  74     union etree_union *child;
  75   } unary;
  76   struct {
  77     node_type type;
  78     const char *name;
  79   } name;
  80   struct {
  81     node_type type;
  82     bfd_vma value;
  83     char *str;
  84   } value;
  85   struct {
  86     node_type type;
  87     asection *section;
  88     bfd_vma value;
  89   } rel;
  90   struct {
  91     node_type type;
  92     union etree_union *child;
  93     const char *message;
  94   } assert_s;
  95 } etree_type;
  96
  97 /* Expression evaluation control.  */
  98 typedef enum
  99 {
 100   /* Parsing linker script.  Will only return "valid" for expressions
 101      that evaluate to a constant.  */
 102   lang_first_phase_enum,
 103   /* Prior to section sizing.  */
 104   lang_mark_phase_enum,
 105   /* During section sizing.  */
 106   lang_allocating_phase_enum,
 107   /* During assignment of symbol values when relaxation in progress.  */
 108   lang_assigning_phase_enum,
 109   /* Final assignment of symbol values.  */
 110   lang_final_phase_enum
 111 } lang_phase_type;
 112
 113 union lang_statement_union;
 114
 115 enum phase_enum {
 116   /* We step through the first four states here as we see the
 117      associated linker script tokens.  */
 118   exp_seg_none,
 119   exp_seg_align_seen,
 120   exp_seg_relro_seen,
 121   exp_seg_end_seen,
 122   /* The last three states are final, and affect the value returned
 123      by XXX_SEGMENT_ALIGN.  */
 124   exp_seg_relro_adjust,
 125   exp_seg_adjust,
 126   exp_seg_done
 127 };
 128
 129 enum relro_enum {
 130   exp_seg_relro_none,
 131   exp_seg_relro_start,
 132   exp_seg_relro_end,
 133 };
 134
 135 typedef struct {
 136   enum phase_enum phase;
 137
 138   bfd_vma base, relro_offset, relro_end, end, pagesize, maxpagesize;
 139
 140   enum relro_enum relro;
 141
 142   union lang_statement_union *relro_start_stat;
 143   union lang_statement_union *relro_end_stat;
 144 } seg_align_type;
 145
 146 struct ldexp_control {
 147   /* Modify expression evaluation depending on this.  */
 148   lang_phase_type phase;
 149
 150   /* Principally used for diagnostics.  */
 151   bfd_boolean assigning_to_dot;
 152
 153   /* Set if the current expression used "dot", SEGMENT_START or
 154      ORIGIN, but not ABSOLUTE or combined symbols in a way that forces
 155      an absolute result.  Used in tracking symbols assigned from dot
 156      outside of output section statements, in order to later convert
 157      them from absolute.  */
 158   bfd_boolean rel_from_abs;
 159
 160   /* If evaluating an assignment, the destination.  Cleared if an
 161      etree_name NAME matches this, to signal a self-assignment.
 162      Note that an etree_name DEFINED does not clear this field, nor
 163      does the false branch of a trinary expression.  */
 164   const char *assign_name;
 165
 166   /* If evaluating an assignment, the source if it is an expression
 167      referencing single etree_name NAME, or a trinary expression where
 168      the true branch references a single etree_name NAME.  */
 169   struct bfd_link_hash_entry *assign_src;
 170
 171   /* Working results.  */
 172   etree_value_type result;
 173   bfd_vma dot;
 174
 175   /* Current dot and section passed to ldexp folder.  */
 176   bfd_vma *dotp;
 177   asection *section;
 178
 179   /* State machine and results for DATASEG.  */
 180   seg_align_type dataseg;
 181 };
 182
 183 extern struct ldexp_control expld;
 184
 185 /* A maps from a segment name to a base address.  */
 186 typedef struct segment_struct {
 187   /* The next segment in the linked list.  */
 188   struct segment_struct *next;
 189   /* The name of the sgement.  */
 190   const char *name;
 191   /* The base address for the segment.  */
 192   bfd_vma value;
 193   /* True if a SEGMENT_START directive corresponding to this segment
 194      has been seen.  */
 195   bfd_boolean used;
 196 } segment_type;
 197
 198 /* The segments specified by the user on the command-line.  */
 199 extern segment_type *segments;
 200
 201 typedef struct _fill_type fill_type;
 202
 203 etree_type *exp_intop
 204   (bfd_vma);
 205 etree_type *exp_bigintop
 206   (bfd_vma, char *);
 207 etree_type *exp_relop
 208   (asection *, bfd_vma);
 209 void exp_fold_tree
 210   (etree_type *, asection *, bfd_vma *);
 211 void exp_fold_tree_no_dot
 212   (etree_type *);
 213 etree_type *exp_binop
 214   (int, etree_type *, etree_type *);
 215 etree_type *exp_trinop
 216   (int,etree_type *, etree_type *, etree_type *);
 217 etree_type *exp_unop
 218   (int, etree_type *);
 219 etree_type *exp_nameop
 220   (int, const char *);
 221 etree_type *exp_assign
 222   (const char *, etree_type *, bfd_boolean);
 223 etree_type *exp_defsym
 224   (const char *, etree_type *);
 225 etree_type *exp_provide
 226   (const char *, etree_type *, bfd_boolean);
 227 etree_type *exp_assert
 228   (etree_type *, const char *);
 229 void exp_print_tree
 230   (etree_type *);
 231 bfd_vma exp_get_vma
 232   (etree_type *, bfd_vma, char *);
 233 int exp_get_value_int
 234   (etree_type *, int, char *);
 235 fill_type *exp_get_fill
 236   (etree_type *, fill_type *, char *);
 237 bfd_vma exp_get_abs_int
 238   (etree_type *, int, char *);
 239 void ldexp_init (void);
 240 void ldexp_finalize_syms (void);
 241 void ldexp_finish (void);
 242
 243 #endif