/* frags.h - Header file for the frag concept.
Copyright (C) 1987-2024 Free Software Foundation, Inc.
This file is part of GAS, the GNU Assembler.
GAS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
GAS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GAS; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, USA. */
#ifndef FRAGS_H
#define FRAGS_H
/* A code fragment (frag) is some known number of chars, followed by some
unknown number of chars. Typically the unknown number of chars is an
instruction address whose size is yet unknown. We always know the greatest
possible size the unknown number of chars may become, and reserve that
much room at the end of the frag.
Once created, frags do not change address during assembly.
We chain the frags in (a) forward-linked list(s). The object-file address
of the 1st char of a frag is generally not known until after relax().
Many things at assembly time describe an address by {object-file-address
of a particular frag}+offset.
BUG: it may be smarter to have a single pointer off to various different
notes for different frag kinds. See how code pans. */
struct frag {
/* Object file address (as an octet offset). */
addressT fr_address;
/* When relaxing multiple times, remember the address the frag had
in the last relax pass. */
addressT last_fr_address;
/* (Fixed) number of octets we know we have. May be 0. */
valueT fr_fix;
/* May be used for (Variable) number of octets after above.
The generic frag handling code no longer makes any use of fr_var. */
offsetT fr_var;
/* For variable-length tail. */
offsetT fr_offset;
/* For variable-length tail. */
symbolS *fr_symbol;
/* Points to opcode low addr byte, for relaxation. */
char *fr_opcode;
/* A serial number for a sequence of frags having at most one alignment
or org frag, and that at the tail of the sequence. */
unsigned int region:16;
/* Flipped each relax pass so we can easily determine whether
fr_address has been adjusted. */
unsigned int relax_marker:1;
/* Used to ensure that all insns are emitted on proper address
boundaries. */
unsigned int has_code:1;
unsigned int insn_addr:6;
/* What state is my tail in? */
relax_stateT fr_type;
relax_substateT fr_subtype;
#ifdef USING_CGEN
/* Don't include this unless using CGEN to keep frag size down. */
struct {
/* CGEN_INSN entry for this instruction. */
const struct cgen_insn *insn;
/* Index into operand table. */
int opindex;
/* Target specific data, usually reloc number. */
int opinfo;
} fr_cgen;
#endif
#define SIZEOF_STRUCT_FRAG \
((char *) zero_address_frag.fr_literal - (char *) &zero_address_frag)
/* We want to say fr_literal[0] above. */
/* Current frag we are building. This frag is incomplete. It is,
however, included in frchain_now. The fr_fix field is bogus;
instead, use frag_now_fix (). */
COMMON fragS *frag_now;
extern addressT frag_now_fix (void);
extern addressT frag_now_fix_octets (void);
/* For foreign-segment symbol fixups. */
COMMON fragS zero_address_frag;
COMMON fragS predefined_address_frag;