ld/ldexp.h

   1 /* ldexp.h -
   2    Copyright (C) 1991-2016 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_dataseg_none,
 119   exp_dataseg_align_seen,
 120   exp_dataseg_relro_seen,
 121   exp_dataseg_end_seen,
 122   /* The last three states are final, and affect the value returned
 123      by DATA_SEGMENT_ALIGN.  */
 124   exp_dataseg_relro_adjust,
 125   exp_dataseg_adjust,
 126   exp_dataseg_done
 127 };
 128
 129 enum relro_enum {
 130   exp_dataseg_relro_none,
 131   exp_dataseg_relro_start,
 132   exp_dataseg_relro_end,
 133 };
 134
 135 struct ldexp_control {
 136   /* Modify expression evaluation depending on this.  */
 137   lang_phase_type phase;
 138
 139   /* Principally used for diagnostics.  */
 140   bfd_boolean assigning_to_dot;
 141
 142   /* Set if the current expression used "dot", SEGMENT_START or
 143      ORIGIN, but not ABSOLUTE or combined symbols in a way that forces
 144      an absolute result.  Used in tracking symbols assigned from dot
 145      outside of output section statements, in order to later convert
 146      them from absolute.  */
 147   bfd_boolean rel_from_abs;
 148
 149   /* If evaluating an assignment, the destination.  Cleared if an
 150      etree_name NAME matches this, to signal a self-assignment.
 151      Note that an etree_name DEFINED does not clear this field, nor
 152      does the false branch of a trinary expression.  */
 153   const char *assign_name;
 154
 155   /* Working results.  */
 156   etree_value_type result;
 157   bfd_vma dot;
 158
 159   /* Current dot and section passed to ldexp folder.  */
 160   bfd_vma *dotp;
 161   asection *section;
 162
 163   /* State machine and results for DATASEG.  */
 164   struct {
 165     enum phase_enum phase;
 166
 167     bfd_vma base, relro_offset, relro_end, end, pagesize, maxpagesize;
 168
 169     enum relro_enum relro;
 170
 171     union lang_statement_union *relro_start_stat;
 172     union lang_statement_union *relro_end_stat;
 173   } dataseg;
 174 };
 175
 176 extern struct ldexp_control expld;
 177
 178 /* A maps from a segment name to a base address.  */
 179 typedef struct segment_struct {
 180   /* The next segment in the linked list.  */
 181   struct segment_struct *next;
 182   /* The name of the sgement.  */
 183   const char *name;
 184   /* The base address for the segment.  */
 185   bfd_vma value;
 186   /* True if a SEGMENT_START directive corresponding to this segment
 187      has been seen.  */
 188   bfd_boolean used;
 189 } segment_type;
 190
 191 /* The segments specified by the user on the command-line.  */
 192 extern segment_type *segments;
 193
 194 typedef struct _fill_type fill_type;
 195
 196 etree_type *exp_intop
 197   (bfd_vma);
 198 etree_type *exp_bigintop
 199   (bfd_vma, char *);
 200 etree_type *exp_relop
 201   (asection *, bfd_vma);
 202 void exp_fold_tree
 203   (etree_type *, asection *, bfd_vma *);
 204 void exp_fold_tree_no_dot
 205   (etree_type *);
 206 etree_type *exp_binop
 207   (int, etree_type *, etree_type *);
 208 etree_type *exp_trinop
 209   (int,etree_type *, etree_type *, etree_type *);
 210 etree_type *exp_unop
 211   (int, etree_type *);
 212 etree_type *exp_nameop
 213   (int, const char *);
 214 etree_type *exp_assign
 215   (const char *, etree_type *, bfd_boolean);
 216 etree_type *exp_defsym
 217   (const char *, etree_type *);
 218 etree_type *exp_provide
 219   (const char *, etree_type *, bfd_boolean);
 220 etree_type *exp_assert
 221   (etree_type *, const char *);
 222 void exp_print_tree
 223   (etree_type *);
 224 bfd_vma exp_get_vma
 225   (etree_type *, bfd_vma, char *);
 226 int exp_get_value_int
 227   (etree_type *, int, char *);
 228 fill_type *exp_get_fill
 229   (etree_type *, fill_type *, char *);
 230 bfd_vma exp_get_abs_int
 231   (etree_type *, int, char *);
 232 void ldexp_init (void);
 233 void ldexp_finalize_syms (void);
 234 void ldexp_finish (void);
 235
 236 #endif