gas/write.h

   1 /* write.h
   2    Copyright (C) 1987-2017 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   /* Only i960-coff and ns32k use this, and i960-coff stores an
 110      integer.  This can probably be folded into tc_fix_data, below.
 111      @@ Alpha also uses it, but only to disable certain relocation
 112      processing.  */
 113   bit_fixS *fx_bit_fixP;
 114
 115   bfd_reloc_code_real_type fx_r_type;
 116
 117   /* This field is sort of misnamed.  It appears to be a sort of random
 118      scratch field, for use by the back ends.  The main gas code doesn't
 119      do anything but initialize it to zero.  The use of it does need to
 120      be coordinated between the cpu and format files, though.  E.g., some
 121      coff targets pass the `addend' field from the cpu file via this
 122      field.  I don't know why the `fx_offset' field above can't be used
 123      for that; investigate later and document. KR  */
 124   valueT fx_addnumber;
 125
 126   /* The location of the instruction which created the reloc, used
 127      in error messages.  */
 128   const char *fx_file;
 129   unsigned fx_line;
 130
 131 #ifdef USING_CGEN
 132   struct {
 133     /* CGEN_INSN entry for this instruction.  */
 134     const struct cgen_insn *insn;
 135     /* Target specific data, usually reloc number.  */
 136     int opinfo;
 137     /* Which ifield this fixup applies to. */
 138     struct cgen_maybe_multi_ifield * field;
 139     /* is this field is the MSB field in a set? */
 140     int msb_field_p;
 141   } fx_cgen;
 142 #endif
 143
 144 #ifdef TC_FIX_TYPE
 145   /* Location where a backend can attach additional data
 146      needed to perform fixups.  */
 147   TC_FIX_TYPE tc_fix_data;
 148 #endif
 149 };
 150
 151 typedef struct fix fixS;
 152
 153 struct reloc_list
 154 {
 155   struct reloc_list *next;
 156   union
 157   {
 158     struct
 159     {
 160       symbolS *offset_sym;
 161       reloc_howto_type *howto;
 162       symbolS *sym;
 163       bfd_vma addend;
 164     } a;
 165     struct
 166     {
 167       asection *sec;
 168       asymbol *s;
 169       arelent r;
 170     } b;
 171   } u;
 172   const char *file;
 173   unsigned int line;
 174 };
 175
 176 extern int finalize_syms;
 177 extern symbolS *abs_section_sym;
 178 extern addressT dot_value;
 179 extern fragS *dot_frag;
 180 extern struct reloc_list* reloc_list;
 181
 182 extern void append (char **, char *, unsigned long);
 183 extern void record_alignment (segT, unsigned);
 184 extern int get_recorded_alignment (segT);
 185 extern void write_object_file (void);
 186 extern long relax_frag (segT, fragS *, long);
 187 extern int relax_segment (struct frag *, segT, int);
 188 extern void number_to_chars_littleendian (char *, valueT, int);
 189 extern void number_to_chars_bigendian (char *, valueT, int);
 190 extern fixS *fix_new
 191   (fragS * frag, int where, int size, symbolS * add_symbol,
 192    offsetT offset, int pcrel, bfd_reloc_code_real_type r_type);
 193 extern fixS *fix_at_start
 194   (fragS * frag, int size, symbolS * add_symbol,
 195    offsetT offset, int pcrel, bfd_reloc_code_real_type r_type);
 196 extern fixS *fix_new_exp
 197   (fragS * frag, int where, int size, expressionS *exp, int pcrel,
 198    bfd_reloc_code_real_type r_type);
 199 extern void write_print_statistics (FILE *);
 200
 201 #endif /* __write_h__ */