write.h revision 1.1.1.8 
1/* write.h
2   Copyright (C) 1987-2022 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
47struct 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  /* pc-relative offset adjust (only used by some CPU specific code).
56     A 4-bit field would be sufficient for most uses, except for ppc
57     which pokes an operand table index here.  Bits may be stolen
58     from here should that be necessary, provided PPC_OPINDEX_MAX is
59     adjusted suitably.  */
60  int fx_pcrel_adjust : 16;
61
62  /* How many bytes are involved? */
63  unsigned fx_size : 8;
64
65  /* Is this a pc-relative relocation?  */
66  unsigned fx_pcrel : 1;
67
68  /* Has this relocation already been applied?  */
69  unsigned fx_done : 1;
70
71  /* Suppress overflow complaints on large addends.  This is used
72     in the PowerPC ELF config to allow large addends on the
73     BFD_RELOC_{LO16,HI16,HI16_S} relocations.
74
75     @@ Can this be determined from BFD?  */
76  unsigned fx_no_overflow : 1;
77
78  /* The value is signed when checking for overflow.  */
79  unsigned fx_signed : 1;
80
81  /* Some bits for the CPU specific code.  */
82  unsigned fx_tcbit : 1;
83  unsigned fx_tcbit2 : 1;
84
85  /* Spare bits.  */
86  unsigned fx_unused : 2;
87
88  bfd_reloc_code_real_type fx_r_type;
89
90  /* Which frag does this fix apply to?  */
91  fragS *fx_frag;
92
93  /* The location within the frag where the fixup occurs.  */
94  unsigned long fx_where;
95
96  /* NULL or Symbol whose value we add in.  */
97  symbolS *fx_addsy;
98
99  /* NULL or Symbol whose value we subtract.  */
100  symbolS *fx_subsy;
101
102  /* Absolute number we add in.  */
103  valueT fx_offset;
104
105  /* The value of dot when the fixup expression was parsed.  */
106  addressT fx_dot_value;
107
108  /* The frag fx_dot_value is based on.  */
109  fragS *fx_dot_frag;
110
111  /* This field is sort of misnamed.  It appears to be a sort of random
112     scratch field, for use by the back ends.  The main gas code doesn't
113     do anything but initialize it to zero.  The use of it does need to
114     be coordinated between the cpu and format files, though.  E.g., some
115     coff targets pass the `addend' field from the cpu file via this
116     field.  I don't know why the `fx_offset' field above can't be used
117     for that; investigate later and document. KR  */
118  valueT fx_addnumber;
119
120  /* The location of the instruction which created the reloc, used
121     in error messages.  */
122  const char *fx_file;
123  unsigned fx_line;
124
125#ifdef USING_CGEN
126  struct {
127    /* CGEN_INSN entry for this instruction.  */
128    const struct cgen_insn *insn;
129    /* Target specific data, usually reloc number.  */
130    int opinfo;
131    /* Which ifield this fixup applies to. */
132    struct cgen_maybe_multi_ifield * field;
133    /* is this field is the MSB field in a set? */
134    int msb_field_p;
135  } fx_cgen;
136#endif
137
138#ifdef TC_FIX_TYPE
139  /* Location where a backend can attach additional data
140     needed to perform fixups.  */
141  TC_FIX_TYPE tc_fix_data;
142#endif
143};
144
145typedef struct fix fixS;
146
147struct reloc_list
148{
149  struct reloc_list *next;
150  union
151  {
152    struct
153    {
154      symbolS *offset_sym;
155      reloc_howto_type *howto;
156      symbolS *sym;
157      bfd_vma addend;
158    } a;
159    struct
160    {
161      asection *sec;
162      asymbol *s;
163      arelent r;
164    } b;
165  } u;
166  const char *file;
167  unsigned int line;
168};
169
170extern int finalize_syms;
171extern symbolS *abs_section_sym;
172extern addressT dot_value;
173extern fragS *dot_frag;
174extern struct reloc_list* reloc_list;
175
176extern void append (char **, char *, unsigned long);
177extern void record_alignment (segT, unsigned);
178extern int get_recorded_alignment (segT);
179extern void write_object_file (void);
180extern long relax_frag (segT, fragS *, long);
181extern int relax_segment (struct frag *, segT, int);
182extern void number_to_chars_littleendian (char *, valueT, int);
183extern void number_to_chars_bigendian (char *, valueT, int);
184extern fixS *fix_new (fragS *, unsigned long, unsigned long, symbolS *,
185		      offsetT, int, bfd_reloc_code_real_type);
186extern fixS *fix_at_start (fragS *, unsigned long, symbolS *,
187			   offsetT, int, bfd_reloc_code_real_type);
188extern fixS *fix_new_exp (fragS *, unsigned long, unsigned long,
189			  expressionS *, int, bfd_reloc_code_real_type);
190extern void write_print_statistics (FILE *);
191extern void as_bad_subtract (fixS *);
192
193#endif /* __write_h__ */
194