ld/ldexp.h

   1 /* ldexp.h -
   2    Copyright (C) 1991-2019 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 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 } lang_phase_type;
 111
 112 union lang_statement_union;
 113
 114 enum phase_enum {
 115   /* We step through the first four states here as we see the
 116      associated linker script tokens.  */
 117   exp_seg_none,
 118   exp_seg_align_seen,
 119   exp_seg_relro_seen,
 120   exp_seg_end_seen,
 121   /* The last three states are final, and affect the value returned
 122      by XXX_SEGMENT_ALIGN.  */
 123   exp_seg_relro_adjust,
 124   exp_seg_adjust,
 125   exp_seg_done
 126 };
 127
 128 enum relro_enum {
 129   exp_seg_relro_none,
 130   exp_seg_relro_start,
 131   exp_seg_relro_end,
 132 };
 133
 134 typedef struct {
 135   enum phase_enum phase;
 136
 137   bfd_vma base, relro_offset, relro_end, end, pagesize, maxpagesize;
 138
 139   enum relro_enum relro;
 140
 141   union lang_statement_union *relro_start_stat;
 142   union lang_statement_union *relro_end_stat;
 143 } seg_align_type;
 144
 145 struct ldexp_control {
 146   /* Modify expression evaluation depending on this.  */
 147   lang_phase_type phase;
 148
 149   /* Principally used for diagnostics.  */
 150   bfd_boolean assigning_to_dot;
 151
 152   /* Set if the current expression used "dot", SEGMENT_START or
 153      ORIGIN, but not ABSOLUTE or combined symbols in a way that forces
 154      an absolute result.  Used in tracking symbols assigned from dot
 155      outside of output section statements, in order to later convert
 156      them from absolute.  */
 157   bfd_boolean rel_from_abs;
 158
 159   /* If evaluating an assignment, the destination.  Cleared if an
 160      etree_name NAME matches this, to signal a self-assignment.
 161      Note that an etree_name DEFINED does not clear this field, nor
 162      does the false branch of a trinary expression.  */
 163   const char *assign_name;
 164
 165   /* If evaluating an assignment, the source if it is an expression
 166      referencing single etree_name NAME, or a trinary expression where
 167      the true branch references a single etree_name NAME.  */
 168   struct bfd_link_hash_entry *assign_src;
 169
 170   /* Working results.  */
 171   etree_value_type result;
 172   bfd_vma dot;
 173
 174   /* Current dot and section passed to ldexp folder.  */
 175   bfd_vma *dotp;
 176   asection *section;
 177
 178   /* State machine and results for DATASEG.  */
 179   seg_align_type dataseg;
 180 };
 181
 182 extern struct ldexp_control expld;
 183
 184 /* A maps from a segment name to a base address.  */
 185 typedef struct segment_struct {
 186   /* The next segment in the linked list.  */
 187   struct segment_struct *next;
 188   /* The name of the sgement.  */
 189   const char *name;
 190   /* The base address for the segment.  */
 191   bfd_vma value;
 192   /* True if a SEGMENT_START directive corresponding to this segment
 193      has been seen.  */
 194   bfd_boolean used;
 195 } segment_type;
 196
 197 /* The segments specified by the user on the command-line.  */
 198 extern segment_type *segments;
 199
 200 typedef struct _fill_type fill_type;
 201
 202 etree_type *exp_intop
 203   (bfd_vma);
 204 etree_type *exp_bigintop
 205   (bfd_vma, char *);
 206 etree_type *exp_relop
 207   (asection *, bfd_vma);
 208 void exp_fold_tree
 209   (etree_type *, asection *, bfd_vma *);
 210 void exp_fold_tree_no_dot
 211   (etree_type *);
 212 etree_type *exp_binop
 213   (int, etree_type *, etree_type *);
 214 etree_type *exp_trinop
 215   (int,etree_type *, etree_type *, etree_type *);
 216 etree_type *exp_unop
 217   (int, etree_type *);
 218 etree_type *exp_nameop
 219   (int, const char *);
 220 etree_type *exp_assign
 221   (const char *, etree_type *, bfd_boolean);
 222 etree_type *exp_defsym
 223   (const char *, etree_type *);
 224 etree_type *exp_provide
 225   (const char *, etree_type *, bfd_boolean);
 226 etree_type *exp_assert
 227   (etree_type *, const char *);
 228 void exp_print_tree
 229   (etree_type *);
 230 bfd_vma exp_get_vma
 231   (etree_type *, bfd_vma, char *);
 232 int exp_get_power
 233   (etree_type *, char *);
 234 fill_type *exp_get_fill
 235   (etree_type *, fill_type *, char *);
 236 bfd_vma exp_get_abs_int
 237   (etree_type *, int, char *);
 238 void ldexp_init (void);
 239 void ldexp_finalize_syms (void);
 240 void ldexp_finish (void);
 241
 242 #endif