gas/write.h

   1 /* write.h
   2    Copyright (C) 1987-2020 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 /*
  44  * FixSs may be built up in any order.
  45  */
  46
  47 struct fix
  48 {
  49   /* Next fixS in linked list, or NULL.  */
  50   struct fix *fx_next;
  51
  52   /* These small fields are grouped together for compactness of
  53      this structure, and efficiency of access on some architectures.  */
  54
  55   /* Is this a pc-relative relocation?  */
  56   unsigned fx_pcrel : 1;
  57
  58   /* Has this relocation already been applied?  */
  59   unsigned fx_done : 1;
  60
  61   /* Suppress overflow complaints on large addends.  This is used
  62      in the PowerPC ELF config to allow large addends on the
  63      BFD_RELOC_{LO16,HI16,HI16_S} relocations.
  64
  65      @@ Can this be determined from BFD?  */
  66   unsigned fx_no_overflow : 1;
  67
  68   /* The value is signed when checking for overflow.  */
  69   unsigned fx_signed : 1;
  70
  71   /* Some bits for the CPU specific code.  */
  72   unsigned fx_tcbit : 1;
  73   unsigned fx_tcbit2 : 1;
  74
  75   /* Spare bits.  */
  76   unsigned fx_unused : 10;
  77
  78   /* pc-relative offset adjust (only used by some CPU specific code) */
  79   int fx_pcrel_adjust : 8;
  80
  81   /* How many bytes are involved? */
  82   unsigned fx_size : 8;
  83
  84   bfd_reloc_code_real_type fx_r_type;
  85
  86   /* Which frag does this fix apply to?  */
  87   fragS *fx_frag;
  88
  89   /* The location within the frag where the fixup occurs.  */
  90   unsigned long fx_where;
  91
  92   /* NULL or Symbol whose value we add in.  */
  93   symbolS *fx_addsy;
  94
  95   /* NULL or Symbol whose value we subtract.  */
  96   symbolS *fx_subsy;
  97
  98   /* Absolute number we add in.  */
  99   valueT fx_offset;
 100
 101   /* The value of dot when the fixup expression was parsed.  */
 102   addressT fx_dot_value;
 103
 104   /* The frag fx_dot_value is based on.  */
 105   fragS *fx_dot_frag;
 106
 107   /* This field is sort of misnamed.  It appears to be a sort of random
 108      scratch field, for use by the back ends.  The main gas code doesn't
 109      do anything but initialize it to zero.  The use of it does need to
 110      be coordinated between the cpu and format files, though.  E.g., some
 111      coff targets pass the `addend' field from the cpu file via this
 112      field.  I don't know why the `fx_offset' field above can't be used
 113      for that; investigate later and document. KR  */
 114   valueT fx_addnumber;
 115
 116   /* The location of the instruction which created the reloc, used
 117      in error messages.  */
 118   const char *fx_file;
 119   unsigned fx_line;
 120
 121 #ifdef USING_CGEN
 122   struct {
 123     /* CGEN_INSN entry for this instruction.  */
 124     const struct cgen_insn *insn;
 125     /* Target specific data, usually reloc number.  */
 126     int opinfo;
 127     /* Which ifield this fixup applies to. */
 128     struct cgen_maybe_multi_ifield * field;
 129     /* is this field is the MSB field in a set? */
 130     int msb_field_p;
 131   } fx_cgen;
 132 #endif
 133
 134 #ifdef TC_FIX_TYPE
 135   /* Location where a backend can attach additional data
 136      needed to perform fixups.  */
 137   TC_FIX_TYPE tc_fix_data;
 138 #endif
 139 };
 140
 141 typedef struct fix fixS;
 142
 143 struct reloc_list
 144 {
 145   struct reloc_list *next;
 146   union
 147   {
 148     struct
 149     {
 150       symbolS *offset_sym;
 151       reloc_howto_type *howto;
 152       symbolS *sym;
 153       bfd_vma addend;
 154     } a;
 155     struct
 156     {
 157       asection *sec;
 158       asymbol *s;
 159       arelent r;
 160     } b;
 161   } u;
 162   const char *file;
 163   unsigned int line;
 164 };
 165
 166 extern int finalize_syms;
 167 extern symbolS *abs_section_sym;
 168 extern addressT dot_value;
 169 extern fragS *dot_frag;
 170 extern struct reloc_list* reloc_list;
 171
 172 extern void append (char **, char *, unsigned long);
 173 extern void record_alignment (segT, unsigned);
 174 extern int get_recorded_alignment (segT);
 175 extern void write_object_file (void);
 176 extern long relax_frag (segT, fragS *, long);
 177 extern int relax_segment (struct frag *, segT, int);
 178 extern void number_to_chars_littleendian (char *, valueT, int);
 179 extern void number_to_chars_bigendian (char *, valueT, int);
 180 extern fixS *fix_new (fragS *, unsigned long, unsigned long, symbolS *,
 181                       offsetT, int, bfd_reloc_code_real_type);
 182 extern fixS *fix_at_start (fragS *, unsigned long, symbolS *,
 183                            offsetT, int, bfd_reloc_code_real_type);
 184 extern fixS *fix_new_exp (fragS *, unsigned long, unsigned long,
 185                           expressionS *, int, bfd_reloc_code_real_type);
 186 extern void write_print_statistics (FILE *);
 187
 188 #endif /* __write_h__ */