write.h revision 1.1.1.9 
1/* write.h
2   Copyright (C) 1987-2024 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  unsigned fx_tcbit3 : 1;
85
86  /* Spare bits.  */
87  unsigned fx_unused : 1;
88
89  bfd_reloc_code_real_type fx_r_type;
90
91  /* Which frag does this fix apply to?  */
92  fragS *fx_frag;
93
94  /* The location within the frag where the fixup occurs.  */
95  unsigned long fx_where;
96
97  /* NULL or Symbol whose value we add in.  */
98  symbolS *fx_addsy;
99
100  /* NULL or Symbol whose value we subtract.  */
101  symbolS *fx_subsy;
102
103  /* Absolute number we add in.  */
104  valueT fx_offset;
105
106  /* The value of dot when the fixup expression was parsed.  */
107  addressT fx_dot_value;
108
109  /* The frag fx_dot_value is based on.  */
110  fragS *fx_dot_frag;
111
112  /* This field is sort of misnamed.  It appears to be a sort of random
113     scratch field, for use by the back ends.  The main gas code doesn't
114     do anything but initialize it to zero.  The use of it does need to
115     be coordinated between the cpu and format files, though.  E.g., some
116     coff targets pass the `addend' field from the cpu file via this
117     field.  I don't know why the `fx_offset' field above can't be used
118     for that; investigate later and document. KR  */
119  valueT fx_addnumber;
120
121  /* The location of the instruction which created the reloc, used
122     in error messages.  */
123  const char *fx_file;
124  unsigned fx_line;
125
126#ifdef USING_CGEN
127  struct {
128    /* CGEN_INSN entry for this instruction.  */
129    const struct cgen_insn *insn;
130    /* Target specific data, usually reloc number.  */
131    int opinfo;
132    /* Which ifield this fixup applies to. */
133    struct cgen_maybe_multi_ifield * field;
134    /* is this field is the MSB field in a set? */
135    int msb_field_p;
136  } fx_cgen;
137#endif
138
139#ifdef TC_FIX_TYPE
140  /* Location where a backend can attach additional data
141     needed to perform fixups.  */
142  TC_FIX_TYPE tc_fix_data;
143#endif
144};
145
146typedef struct fix fixS;
147
148struct reloc_list
149{
150  struct reloc_list *next;
151  union
152  {
153    struct
154    {
155      symbolS *offset_sym;
156      reloc_howto_type *howto;
157      symbolS *sym;
158      bfd_vma addend;
159    } a;
160    struct
161    {
162      asection *sec;
163      asymbol *s;
164      arelent r;
165    } b;
166  } u;
167  const char *file;
168  unsigned int line;
169};
170
171extern int finalize_syms;
172extern symbolS *abs_section_sym;
173extern addressT dot_value;
174extern fragS *dot_frag;
175extern struct reloc_list* reloc_list;
176
177extern void append (char **, char *, unsigned long);
178extern void record_alignment (segT, unsigned);
179extern int get_recorded_alignment (segT);
180extern void write_object_file (void);
181extern long relax_frag (segT, fragS *, long);
182extern int relax_segment (struct frag *, segT, int);
183extern void number_to_chars_littleendian (char *, valueT, int);
184extern void number_to_chars_bigendian (char *, valueT, int);
185extern fixS *fix_new (fragS *, unsigned long, unsigned long, symbolS *,
186		      offsetT, int, bfd_reloc_code_real_type);
187extern fixS *fix_at_start (fragS *, unsigned long, symbolS *,
188			   offsetT, int, bfd_reloc_code_real_type);
189extern fixS *fix_new_exp (fragS *, unsigned long, unsigned long,
190			  expressionS *, int, bfd_reloc_code_real_type);
191extern void write_print_statistics (FILE *);
192extern void as_bad_subtract (fixS *);
193
194#endif /* __write_h__ */
195