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      1 /* write.h
      2    Copyright (C) 1987-2016 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 #include "bit_fix.h"
     31 
     32 /*
     33  * FixSs may be built up in any order.
     34  */
     35 
     36 struct fix
     37 {
     38   /* These small fields are grouped together for compactness of
     39      this structure, and efficiency of access on some architectures.  */
     40 
     41   /* Is this a pc-relative relocation?  */
     42   unsigned fx_pcrel : 1;
     43 
     44   /* Is this value an immediate displacement?  */
     45   /* Only used on ns32k; merge it into TC_FIX_TYPE sometime.  */
     46   unsigned fx_im_disp : 2;
     47 
     48   /* Some bits for the CPU specific code.  */
     49   unsigned fx_tcbit : 1;
     50   unsigned fx_tcbit2 : 1;
     51 
     52   /* Has this relocation already been applied?  */
     53   unsigned fx_done : 1;
     54 
     55   /* Suppress overflow complaints on large addends.  This is used
     56      in the PowerPC ELF config to allow large addends on the
     57      BFD_RELOC_{LO16,HI16,HI16_S} relocations.
     58 
     59      @@ Can this be determined from BFD?  */
     60   unsigned fx_no_overflow : 1;
     61 
     62   /* The value is signed when checking for overflow.  */
     63   unsigned fx_signed : 1;
     64 
     65   /* pc-relative offset adjust (only used by some CPU specific code) */
     66   signed char fx_pcrel_adjust;
     67 
     68   /* How many bytes are involved? */
     69   unsigned char fx_size;
     70 
     71   /* Which frag does this fix apply to?  */
     72   fragS *fx_frag;
     73 
     74   /* Where is the first byte to fix up?  */
     75   long fx_where;
     76 
     77   /* NULL or Symbol whose value we add in.  */
     78   symbolS *fx_addsy;
     79 
     80   /* NULL or Symbol whose value we subtract.  */
     81   symbolS *fx_subsy;
     82 
     83   /* Absolute number we add in.  */
     84   valueT fx_offset;
     85 
     86   /* The value of dot when the fixup expression was parsed.  */
     87   addressT fx_dot_value;
     88 
     89   /* The frag fx_dot_value is based on.  */
     90   fragS *fx_dot_frag;
     91 
     92   /* Next fixS in linked list, or NULL.  */
     93   struct fix *fx_next;
     94 
     95   /* If NULL, no bitfix's to do.  */
     96   /* Only i960-coff and ns32k use this, and i960-coff stores an
     97      integer.  This can probably be folded into tc_fix_data, below.
     98      @@ Alpha also uses it, but only to disable certain relocation
     99      processing.  */
    100   bit_fixS *fx_bit_fixP;
    101 
    102   bfd_reloc_code_real_type fx_r_type;
    103 
    104   /* This field is sort of misnamed.  It appears to be a sort of random
    105      scratch field, for use by the back ends.  The main gas code doesn't
    106      do anything but initialize it to zero.  The use of it does need to
    107      be coordinated between the cpu and format files, though.  E.g., some
    108      coff targets pass the `addend' field from the cpu file via this
    109      field.  I don't know why the `fx_offset' field above can't be used
    110      for that; investigate later and document. KR  */
    111   valueT fx_addnumber;
    112 
    113   /* The location of the instruction which created the reloc, used
    114      in error messages.  */
    115   const char *fx_file;
    116   unsigned fx_line;
    117 
    118 #ifdef USING_CGEN
    119   struct {
    120     /* CGEN_INSN entry for this instruction.  */
    121     const struct cgen_insn *insn;
    122     /* Target specific data, usually reloc number.  */
    123     int opinfo;
    124     /* Which ifield this fixup applies to. */
    125     struct cgen_maybe_multi_ifield * field;
    126     /* is this field is the MSB field in a set? */
    127     int msb_field_p;
    128   } fx_cgen;
    129 #endif
    130 
    131 #ifdef TC_FIX_TYPE
    132   /* Location where a backend can attach additional data
    133      needed to perform fixups.  */
    134   TC_FIX_TYPE tc_fix_data;
    135 #endif
    136 };
    137 
    138 typedef struct fix fixS;
    139 
    140 struct reloc_list
    141 {
    142   struct reloc_list *next;
    143   union
    144   {
    145     struct
    146     {
    147       symbolS *offset_sym;
    148       reloc_howto_type *howto;
    149       symbolS *sym;
    150       bfd_vma addend;
    151     } a;
    152     struct
    153     {
    154       asection *sec;
    155       asymbol *s;
    156       arelent r;
    157     } b;
    158   } u;
    159   const char *file;
    160   unsigned int line;
    161 };
    162 
    163 extern int finalize_syms;
    164 extern symbolS *abs_section_sym;
    165 extern addressT dot_value;
    166 extern fragS *dot_frag;
    167 extern struct reloc_list* reloc_list;
    168 
    169 extern void append (char **, char *, unsigned long);
    170 extern void record_alignment (segT, unsigned);
    171 extern int get_recorded_alignment (segT);
    172 extern void write_object_file (void);
    173 extern long relax_frag (segT, fragS *, long);
    174 extern int relax_segment (struct frag *, segT, int);
    175 extern void number_to_chars_littleendian (char *, valueT, int);
    176 extern void number_to_chars_bigendian (char *, valueT, int);
    177 extern fixS *fix_new
    178   (fragS * frag, int where, int size, symbolS * add_symbol,
    179    offsetT offset, int pcrel, bfd_reloc_code_real_type r_type);
    180 extern fixS *fix_at_start
    181   (fragS * frag, int size, symbolS * add_symbol,
    182    offsetT offset, int pcrel, bfd_reloc_code_real_type r_type);
    183 extern fixS *fix_new_exp
    184   (fragS * frag, int where, int size, expressionS *exp, int pcrel,
    185    bfd_reloc_code_real_type r_type);
    186 extern void write_print_statistics (FILE *);
    187 
    188 #endif /* __write_h__ */
    189