old-cross-binutils/gas/config/obj-aout.c
Ian Lance Taylor 02d4e9238a Add weak symbols as an extension to a.out.
* read.c (pseudo_set): Only preserve external bit for OBJ_AOUT and
	OBJ_BOUT if not BFD_ASSEMBLER.
	* config/aout_gnu.h (N_WEAKU, N_WEAKA, N_WEAKT, N_WEAKD, N_WEAKB):
	Define as in ../include/aout/aout64.h.
	* config/obj-aout.h (OBJ_SYMFIELD_TYPE): If not BFD_ASSEMBLER,
	define as char.
	(S_GET_WEAK, S_SET_WEAK): Define if not BFD_ASSEMBLER.
	* config/obj-aout.c (obj_pseudo_table): Add "weak".
	(obj_emit_symbols): Adjust type of weak symbols.
	(obj_aout_weak): New static function.
1994-06-11 20:45:49 +00:00

522 lines
13 KiB
C

/* a.out object file format
Copyright (C) 1989, 1990, 1991 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 2,
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, 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "as.h"
#ifdef BFD_ASSEMBLER
#undef NO_RELOC
#include "aout/aout64.h"
#endif
#include "obstack.h"
#ifndef BFD_ASSEMBLER
/* in: segT out: N_TYPE bits */
const short seg_N_TYPE[] =
{
N_ABS,
N_TEXT,
N_DATA,
N_BSS,
N_UNDF, /* unknown */
N_UNDF, /* error */
N_UNDF, /* expression */
N_UNDF, /* debug */
N_UNDF, /* ntv */
N_UNDF, /* ptv */
N_REGISTER, /* register */
};
const segT N_TYPE_seg[N_TYPE + 2] =
{ /* N_TYPE == 0x1E = 32-2 */
SEG_UNKNOWN, /* N_UNDF == 0 */
SEG_GOOF,
SEG_ABSOLUTE, /* N_ABS == 2 */
SEG_GOOF,
SEG_TEXT, /* N_TEXT == 4 */
SEG_GOOF,
SEG_DATA, /* N_DATA == 6 */
SEG_GOOF,
SEG_BSS, /* N_BSS == 8 */
SEG_GOOF,
SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
SEG_GOOF, SEG_GOOF, SEG_GOOF, SEG_GOOF,
SEG_REGISTER, /* dummy N_REGISTER for regs = 30 */
SEG_GOOF,
};
#endif
static void obj_aout_line PARAMS ((int));
static void obj_aout_weak PARAMS ((int));
const pseudo_typeS obj_pseudo_table[] =
{
{"line", obj_aout_line, 0}, /* source code line number */
{"ln", obj_aout_line, 0}, /* coff line number that we use anyway */
{"weak", obj_aout_weak, 0}, /* mark symbol as weak. */
/* coff debug pseudos (ignored) */
{"def", s_ignore, 0},
{"dim", s_ignore, 0},
{"endef", s_ignore, 0},
{"ident", s_ignore, 0},
{"line", s_ignore, 0},
{"ln", s_ignore, 0},
{"scl", s_ignore, 0},
{"size", s_ignore, 0},
{"tag", s_ignore, 0},
{"type", s_ignore, 0},
{"val", s_ignore, 0},
{"version", s_ignore, 0},
{"optim", s_ignore, 0}, /* For sun386i cc (?) */
/* other stuff */
{"ABORT", s_abort, 0},
{NULL} /* end sentinel */
}; /* obj_pseudo_table */
#ifdef BFD_ASSEMBLER
void
obj_aout_frob_symbol (sym, punt)
symbolS *sym;
int *punt;
{
flagword flags;
asection *sec;
int desc, type, other;
flags = sym->bsym->flags;
desc = S_GET_DESC (sym);
type = S_GET_TYPE (sym);
other = S_GET_OTHER (sym);
sec = sym->bsym->section;
/* Only frob simple symbols this way right now. */
if (! (type & ~ (N_TYPE | N_EXT)))
{
if (type == (N_UNDF | N_EXT)
&& sec == &bfd_abs_section)
sym->bsym->section = sec = &bfd_und_section;
if ((type & N_TYPE) != N_INDR
&& (type & N_TYPE) != N_SETA
&& (type & N_TYPE) != N_SETT
&& (type & N_TYPE) != N_SETD
&& (type & N_TYPE) != N_SETB
&& type != N_WARNING
&& (sec == &bfd_abs_section
|| sec == &bfd_und_section))
return;
if (flags & BSF_EXPORT)
type |= N_EXT;
switch (type & N_TYPE)
{
case N_SETA:
case N_SETT:
case N_SETD:
case N_SETB:
/* Set the debugging flag for constructor symbols so that
BFD leaves them alone. */
sym->bsym->flags |= BSF_DEBUGGING;
break;
case N_INDR:
/* Put indirect symbols in the indirect section. */
sym->bsym->section = &bfd_ind_section;
sym->bsym->flags |= BSF_INDIRECT;
if (type & N_EXT)
{
sym->bsym->flags |= BSF_EXPORT;
sym->bsym->flags &=~ BSF_LOCAL;
}
break;
case N_WARNING:
/* Mark warning symbols. */
sym->bsym->flags |= BSF_WARNING;
break;
}
}
else
{
sym->bsym->flags |= BSF_DEBUGGING;
}
S_SET_TYPE (sym, type);
}
void
obj_aout_frob_file ()
{
/* Relocation processing may require knowing the VMAs of the sections.
Since writing to a section will cause the BFD back end to compute the
VMAs, fake it out here.... */
bfd_byte b = 0;
boolean x = true;
if (bfd_section_size (stdoutput, text_section) != 0)
{
x = bfd_set_section_contents (stdoutput, text_section, &b, (file_ptr) 0,
(bfd_size_type) 1);
}
else if (bfd_section_size (stdoutput, data_section) != 0)
{
x = bfd_set_section_contents (stdoutput, data_section, &b, (file_ptr) 0,
(bfd_size_type) 1);
}
assert (x == true);
}
#else
/* Relocation. */
/*
* emit_relocations()
*
* Crawl along a fixS chain. Emit the segment's relocations.
*/
void
obj_emit_relocations (where, fixP, segment_address_in_file)
char **where;
fixS *fixP; /* Fixup chain for this segment. */
relax_addressT segment_address_in_file;
{
for (; fixP; fixP = fixP->fx_next)
if (fixP->fx_done == 0)
{
tc_aout_fix_to_chars (*where, fixP, segment_address_in_file);
*where += md_reloc_size;
}
}
#ifndef obj_header_append
/* Aout file generation & utilities */
void
obj_header_append (where, headers)
char **where;
object_headers *headers;
{
tc_headers_hook (headers);
#ifdef CROSS_COMPILE
md_number_to_chars (*where, headers->header.a_info, sizeof (headers->header.a_info));
*where += sizeof (headers->header.a_info);
md_number_to_chars (*where, headers->header.a_text, sizeof (headers->header.a_text));
*where += sizeof (headers->header.a_text);
md_number_to_chars (*where, headers->header.a_data, sizeof (headers->header.a_data));
*where += sizeof (headers->header.a_data);
md_number_to_chars (*where, headers->header.a_bss, sizeof (headers->header.a_bss));
*where += sizeof (headers->header.a_bss);
md_number_to_chars (*where, headers->header.a_syms, sizeof (headers->header.a_syms));
*where += sizeof (headers->header.a_syms);
md_number_to_chars (*where, headers->header.a_entry, sizeof (headers->header.a_entry));
*where += sizeof (headers->header.a_entry);
md_number_to_chars (*where, headers->header.a_trsize, sizeof (headers->header.a_trsize));
*where += sizeof (headers->header.a_trsize);
md_number_to_chars (*where, headers->header.a_drsize, sizeof (headers->header.a_drsize));
*where += sizeof (headers->header.a_drsize);
#else /* CROSS_COMPILE */
append (where, (char *) &headers->header, sizeof (headers->header));
#endif /* CROSS_COMPILE */
}
#endif
void
obj_symbol_to_chars (where, symbolP)
char **where;
symbolS *symbolP;
{
md_number_to_chars ((char *) &(S_GET_OFFSET (symbolP)), S_GET_OFFSET (symbolP), sizeof (S_GET_OFFSET (symbolP)));
md_number_to_chars ((char *) &(S_GET_DESC (symbolP)), S_GET_DESC (symbolP), sizeof (S_GET_DESC (symbolP)));
md_number_to_chars ((char *) &(symbolP->sy_symbol.n_value), S_GET_VALUE (symbolP), sizeof (symbolP->sy_symbol.n_value));
append (where, (char *) &symbolP->sy_symbol, sizeof (obj_symbol_type));
}
void
obj_emit_symbols (where, symbol_rootP)
char **where;
symbolS *symbol_rootP;
{
symbolS *symbolP;
/* Emit all symbols left in the symbol chain. */
for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
{
/* Used to save the offset of the name. It is used to point
to the string in memory but must be a file offset. */
register char *temp;
temp = S_GET_NAME (symbolP);
S_SET_OFFSET (symbolP, symbolP->sy_name_offset);
/* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
if (!S_IS_DEBUG (symbolP) && !S_IS_DEFINED (symbolP))
S_SET_EXTERNAL (symbolP);
/* Adjust the type of a weak symbol. */
if (S_GET_WEAK (symbolP))
{
switch (S_GET_TYPE (symbolP))
{
case N_UNDF: S_SET_TYPE (symbolP, N_WEAKU); break;
case N_ABS: S_SET_TYPE (symbolP, N_WEAKA); break;
case N_TEXT: S_SET_TYPE (symbolP, N_WEAKT); break;
case N_DATA: S_SET_TYPE (symbolP, N_WEAKD); break;
case N_BSS: S_SET_TYPE (symbolP, N_WEAKB); break;
default: as_bad ("%s: bad type for weak symbol", temp); break;
}
}
obj_symbol_to_chars (where, symbolP);
S_SET_NAME (symbolP, temp);
}
}
#endif /* ! BFD_ASSEMBLER */
static void
obj_aout_line (ignore)
int ignore;
{
/* Assume delimiter is part of expression.
BSD4.2 as fails with delightful bug, so we
are not being incompatible here. */
new_logical_line ((char *) NULL, (int) (get_absolute_expression ()));
demand_empty_rest_of_line ();
} /* obj_aout_line() */
/* Handle .weak. This is a GNU extension. */
static void
obj_aout_weak (ignore)
int ignore;
{
char *name;
int c;
symbolS *symbolP;
do
{
name = input_line_pointer;
c = get_symbol_end ();
symbolP = symbol_find_or_make (name);
*input_line_pointer = c;
SKIP_WHITESPACE ();
S_SET_WEAK (symbolP);
if (c == ',')
{
input_line_pointer++;
SKIP_WHITESPACE ();
if (*input_line_pointer == '\n')
c = '\n';
}
}
while (c == ',');
demand_empty_rest_of_line ();
}
void
obj_read_begin_hook ()
{
}
#ifndef BFD_ASSEMBLER
void
obj_crawl_symbol_chain (headers)
object_headers *headers;
{
symbolS *symbolP;
symbolS **symbolPP;
int symbol_number = 0;
tc_crawl_symbol_chain (headers);
symbolPP = &symbol_rootP; /*->last symbol chain link. */
while ((symbolP = *symbolPP) != NULL)
{
if (flag_readonly_data_in_text && (S_GET_SEGMENT (symbolP) == SEG_DATA))
{
S_SET_SEGMENT (symbolP, SEG_TEXT);
} /* if pusing data into text */
resolve_symbol_value (symbolP);
/* OK, here is how we decide which symbols go out into the brave
new symtab. Symbols that do are:
* symbols with no name (stabd's?)
* symbols with debug info in their N_TYPE
Symbols that don't are:
* symbols that are registers
* symbols with \1 as their 3rd character (numeric labels)
* "local labels" as defined by S_LOCAL_NAME(name) if the -L
switch was passed to gas.
All other symbols are output. We complain if a deleted
symbol was marked external. */
if (!S_IS_REGISTER (symbolP)
&& (!S_GET_NAME (symbolP)
|| S_IS_DEBUG (symbolP)
|| !S_IS_DEFINED (symbolP)
|| S_IS_EXTERNAL (symbolP)
|| (S_GET_NAME (symbolP)[0] != '\001'
&& (flag_keep_locals || !S_LOCAL_NAME (symbolP)))))
{
symbolP->sy_number = symbol_number++;
/* The + 1 after strlen account for the \0 at the
end of each string */
if (!S_IS_STABD (symbolP))
{
/* Ordinary case. */
symbolP->sy_name_offset = string_byte_count;
string_byte_count += strlen (S_GET_NAME (symbolP)) + 1;
}
else /* .Stabd case. */
symbolP->sy_name_offset = 0;
symbolPP = &(symbol_next (symbolP));
}
else
{
if (S_IS_EXTERNAL (symbolP) || !S_IS_DEFINED (symbolP))
/* This warning should never get triggered any more.
Well, maybe if you're doing twisted things with
register names... */
{
as_bad ("Local symbol %s never defined.", decode_local_label_name (S_GET_NAME (symbolP)));
} /* oops. */
/* Unhook it from the chain */
*symbolPP = symbol_next (symbolP);
} /* if this symbol should be in the output */
} /* for each symbol */
H_SET_SYMBOL_TABLE_SIZE (headers, symbol_number);
}
/*
* Find strings by crawling along symbol table chain.
*/
void
obj_emit_strings (where)
char **where;
{
symbolS *symbolP;
#ifdef CROSS_COMPILE
/* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
md_number_to_chars (*where, string_byte_count, sizeof (string_byte_count));
*where += sizeof (string_byte_count);
#else /* CROSS_COMPILE */
append (where, (char *) &string_byte_count, (unsigned long) sizeof (string_byte_count));
#endif /* CROSS_COMPILE */
for (symbolP = symbol_rootP; symbolP; symbolP = symbol_next (symbolP))
{
if (S_GET_NAME (symbolP))
append (&next_object_file_charP, S_GET_NAME (symbolP),
(unsigned long) (strlen (S_GET_NAME (symbolP)) + 1));
} /* walk symbol chain */
}
#ifndef AOUT_VERSION
#define AOUT_VERSION 0
#endif
void
obj_pre_write_hook (headers)
object_headers *headers;
{
H_SET_DYNAMIC (headers, 0);
H_SET_VERSION (headers, AOUT_VERSION);
H_SET_MACHTYPE (headers, AOUT_MACHTYPE);
tc_aout_pre_write_hook (headers);
}
void
DEFUN_VOID (s_sect)
{
/* Strip out the section name */
char *section_name;
char *section_name_end;
char c;
unsigned int len;
unsigned int exp;
char *save;
section_name = input_line_pointer;
c = get_symbol_end ();
section_name_end = input_line_pointer;
len = section_name_end - section_name;
input_line_pointer++;
save = input_line_pointer;
SKIP_WHITESPACE ();
if (c == ',')
{
exp = get_absolute_expression ();
}
else if (*input_line_pointer == ',')
{
input_line_pointer++;
exp = get_absolute_expression ();
}
else
{
input_line_pointer = save;
exp = 0;
}
if (exp >= 1000)
{
as_bad ("subsegment index too high");
}
if (strcmp (section_name, ".text") == 0)
{
subseg_set (SEG_TEXT, (subsegT) exp);
}
if (strcmp (section_name, ".data") == 0)
{
if (flag_readonly_data_in_text)
subseg_set (SEG_TEXT, (subsegT) exp + 1000);
else
subseg_set (SEG_DATA, (subsegT) exp);
}
*section_name_end = c;
}
#endif /* ! BFD_ASSEMBLER */
/* end of obj-aout.c */