gas/write.h

   1 /* write.h
   2    Copyright (C) 1987-2018 Free Software Foundation, Inc.
   3
   4    This file is part of GAS, the GNU Assembler.
   5
   6    GAS 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, or (at your option)
   9    any later version.
  10
  11    GAS 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 GAS; see the file COPYING.  If not, write to the Free
  18    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
  19    02110-1301, USA.  */
  20
  21 #ifndef __write_h__
  22 #define __write_h__
  23
  24 /* This is the name of a fake symbol which will never appear in the
  25    assembler output.  S_IS_LOCAL detects it because of the \001.  */
  26 #ifndef FAKE_LABEL_NAME
  27 #define FAKE_LABEL_NAME "L0\001"
  28 #endif
  29
  30 /* This is a special character that is used to indicate a fake label.
  31    It must be present in FAKE_LABEL_NAME, although it does not have to
  32    be the first character.  It must not be a character that would be
  33    found in a valid symbol name.
  34
  35    Also be aware that the function _bfd_elf_is_local_label_name in
  36    bfd/elf.c has an implicit assumption that FAKE_LABEL_CHAR is '\001'.
  37    If this is not the case then FAKE_LABEL_NAME must start with ".L" in
  38    order for the function to continue working.  */
  39 #ifndef FAKE_LABEL_CHAR
  40 #define FAKE_LABEL_CHAR '\001'
  41 #endif
  42
  43 #include "bit_fix.h"
  44
  45 /*
  46  * FixSs may be built up in any order.
  47  */
  48
  49 struct fix
  50 {
  51   /* These small fields are grouped together for compactness of
  52      this structure, and efficiency of access on some architectures.  */
  53
  54   /* Is this a pc-relative relocation?  */
  55   unsigned fx_pcrel : 1;
  56
  57   /* Is this value an immediate displacement?  */
  58   /* Only used on ns32k; merge it into TC_FIX_TYPE sometime.  */
  59   unsigned fx_im_disp : 2;
  60
  61   /* Some bits for the CPU specific code.  */
  62   unsigned fx_tcbit : 1;
  63   unsigned fx_tcbit2 : 1;
  64
  65   /* Has this relocation already been applied?  */
  66   unsigned fx_done : 1;
  67
  68   /* Suppress overflow complaints on large addends.  This is used
  69      in the PowerPC ELF config to allow large addends on the
  70      BFD_RELOC_{LO16,HI16,HI16_S} relocations.
  71
  72      @@ Can this be determined from BFD?  */
  73   unsigned fx_no_overflow : 1;
  74
  75   /* The value is signed when checking for overflow.  */
  76   unsigned fx_signed : 1;
  77
  78   /* pc-relative offset adjust (only used by some CPU specific code) */
  79   signed char fx_pcrel_adjust;
  80
  81   /* How many bytes are involved? */
  82   unsigned char fx_size;
  83
  84   /* Which frag does this fix apply to?  */
  85   fragS *fx_frag;
  86
  87   /* Where is the first byte to fix up?  */
  88   long fx_where;
  89
  90   /* NULL or Symbol whose value we add in.  */
  91   symbolS *fx_addsy;
  92
  93   /* NULL or Symbol whose value we subtract.  */
  94   symbolS *fx_subsy;
  95
  96   /* Absolute number we add in.  */
  97   valueT fx_offset;
  98
  99   /* The value of dot when the fixup expression was parsed.  */
 100   addressT fx_dot_value;
 101
 102   /* The frag fx_dot_value is based on.  */
 103   fragS *fx_dot_frag;
 104
 105   /* Next fixS in linked list, or NULL.  */
 106   struct fix *fx_next;
 107
 108   /* If NULL, no bitfix's to do.  */
 109   bit_fixS *fx_bit_fixP;
 110
 111   bfd_reloc_code_real_type fx_r_type;
 112
 113   /* This field is sort of misnamed.  It appears to be a sort of random
 114      scratch field, for use by the back ends.  The main gas code doesn't
 115      do anything but initialize it to zero.  The use of it does need to
 116      be coordinated between the cpu and format files, though.  E.g., some
 117      coff targets pass the `addend' field from the cpu file via this
 118      field.  I don't know why the `fx_offset' field above can't be used
 119      for that; investigate later and document. KR  */
 120   valueT fx_addnumber;
 121
 122   /* The location of the instruction which created the reloc, used
 123      in error messages.  */
 124   const char *fx_file;
 125   unsigned fx_line;
 126
 127 #ifdef USING_CGEN
 128   struct {
 129     /* CGEN_INSN entry for this instruction.  */
 130     const struct cgen_insn *insn;
 131     /* Target specific data, usually reloc number.  */
 132     int opinfo;
 133     /* Which ifield this fixup applies to. */
 134     struct cgen_maybe_multi_ifield * field;
 135     /* is this field is the MSB field in a set? */
 136     int msb_field_p;
 137   } fx_cgen;
 138 #endif
 139
 140 #ifdef TC_FIX_TYPE
 141   /* Location where a backend can attach additional data
 142      needed to perform fixups.  */
 143   TC_FIX_TYPE tc_fix_data;
 144 #endif
 145 };
 146
 147 typedef struct fix fixS;
 148
 149 struct reloc_list
 150 {
 151   struct reloc_list *next;
 152   union
 153   {
 154     struct
 155     {
 156       symbolS *offset_sym;
 157       reloc_howto_type *howto;
 158       symbolS *sym;
 159       bfd_vma addend;
 160     } a;
 161     struct
 162     {
 163       asection *sec;
 164       asymbol *s;
 165       arelent r;
 166     } b;
 167   } u;
 168   const char *file;
 169   unsigned int line;
 170 };
 171
 172 extern int finalize_syms;
 173 extern symbolS *abs_section_sym;
 174 extern addressT dot_value;
 175 extern fragS *dot_frag;
 176 extern struct reloc_list* reloc_list;
 177
 178 extern void append (char **, char *, unsigned long);
 179 extern void record_alignment (segT, unsigned);
 180 extern int get_recorded_alignment (segT);
 181 extern void write_object_file (void);
 182 extern long relax_frag (segT, fragS *, long);
 183 extern int relax_segment (struct frag *, segT, int);
 184 extern void number_to_chars_littleendian (char *, valueT, int);
 185 extern void number_to_chars_bigendian (char *, valueT, int);
 186 extern fixS *fix_new
 187   (fragS * frag, int where, int size, symbolS * add_symbol,
 188    offsetT offset, int pcrel, bfd_reloc_code_real_type r_type);
 189 extern fixS *fix_at_start
 190   (fragS * frag, int size, symbolS * add_symbol,
 191    offsetT offset, int pcrel, bfd_reloc_code_real_type r_type);
 192 extern fixS *fix_new_exp
 193   (fragS * frag, int where, int size, expressionS *exp, int pcrel,
 194    bfd_reloc_code_real_type r_type);
 195 extern void write_print_statistics (FILE *);
 196
 197 #endif /* __write_h__ */