1 /* b.out object file format
2 Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
6 GAS is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as
8 published by the Free Software Foundation; either version 2,
9 or (at your option) any later version.
11 GAS is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
14 the GNU General Public License for more details.
16 You should have received a copy of the GNU General Public
17 License along with GAS; see the file COPYING. If not, write
18 to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
22 const short /* in: segT out: N_TYPE bits */
31 N_UNDF
, /* expression */
35 N_REGISTER
, /* register */
38 const segT N_TYPE_seg
[N_TYPE
+ 2] =
39 { /* N_TYPE == 0x1E = 32-2 */
40 SEG_UNKNOWN
, /* N_UNDF == 0 */
42 SEG_ABSOLUTE
, /* N_ABS == 2 */
44 SEG_TEXT
, /* N_TEXT == 4 */
46 SEG_DATA
, /* N_DATA == 6 */
48 SEG_BSS
, /* N_BSS == 8 */
50 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
51 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
52 SEG_GOOF
, SEG_GOOF
, SEG_GOOF
, SEG_GOOF
,
53 SEG_REGISTER
, /* dummy N_REGISTER for regs = 30 */
57 static void obj_bout_line
PARAMS ((int));
59 const pseudo_typeS obj_pseudo_table
[] =
61 {"line", obj_bout_line
, 0}, /* source code line number */
63 /* coff debugging directives. Currently ignored silently */
66 {"endef", s_ignore
, 0},
69 {"size", s_ignore
, 0},
71 {"type", s_ignore
, 0},
74 /* other stuff we don't handle */
75 {"ABORT", s_ignore
, 0},
76 {"ident", s_ignore
, 0},
78 {NULL
} /* end sentinel */
79 }; /* obj_pseudo_table */
86 * Crawl along a fixS chain. Emit the segment's relocations.
89 obj_emit_relocations (where
, fixP
, segment_address_in_file
)
91 fixS
*fixP
; /* Fixup chain for this segment. */
92 relax_addressT segment_address_in_file
;
94 for (; fixP
; fixP
= fixP
->fx_next
)
96 if (fixP
->fx_addsy
!= NULL
97 || fixP
->fx_r_type
!= NO_RELOC
)
99 tc_bout_fix_to_chars (*where
, fixP
, segment_address_in_file
);
100 *where
+= sizeof (struct relocation_info
);
101 } /* if there's a symbol */
102 } /* for each fixup */
104 } /* emit_relocations() */
106 /* Aout file generation & utilities */
108 /* Convert a lvalue to machine dependent data */
110 obj_header_append (where
, headers
)
112 object_headers
*headers
;
114 /* Always leave in host byte order */
116 headers
->header
.a_talign
= section_alignment
[SEG_TEXT
];
118 if (headers
->header
.a_talign
< 2)
120 headers
->header
.a_talign
= 2;
121 } /* force to at least 2 */
123 headers
->header
.a_dalign
= section_alignment
[SEG_DATA
];
124 headers
->header
.a_balign
= section_alignment
[SEG_BSS
];
126 headers
->header
.a_tload
= 0;
127 headers
->header
.a_dload
= md_section_align (SEG_DATA
, H_GET_TEXT_SIZE (headers
));
129 headers
->header
.a_relaxable
= linkrelax
;
132 md_number_to_chars (*where
, headers
->header
.a_magic
, sizeof (headers
->header
.a_magic
));
133 *where
+= sizeof (headers
->header
.a_magic
);
134 md_number_to_chars (*where
, headers
->header
.a_text
, sizeof (headers
->header
.a_text
));
135 *where
+= sizeof (headers
->header
.a_text
);
136 md_number_to_chars (*where
, headers
->header
.a_data
, sizeof (headers
->header
.a_data
));
137 *where
+= sizeof (headers
->header
.a_data
);
138 md_number_to_chars (*where
, headers
->header
.a_bss
, sizeof (headers
->header
.a_bss
));
139 *where
+= sizeof (headers
->header
.a_bss
);
140 md_number_to_chars (*where
, headers
->header
.a_syms
, sizeof (headers
->header
.a_syms
));
141 *where
+= sizeof (headers
->header
.a_syms
);
142 md_number_to_chars (*where
, headers
->header
.a_entry
, sizeof (headers
->header
.a_entry
));
143 *where
+= sizeof (headers
->header
.a_entry
);
144 md_number_to_chars (*where
, headers
->header
.a_trsize
, sizeof (headers
->header
.a_trsize
));
145 *where
+= sizeof (headers
->header
.a_trsize
);
146 md_number_to_chars (*where
, headers
->header
.a_drsize
, sizeof (headers
->header
.a_drsize
));
147 *where
+= sizeof (headers
->header
.a_drsize
);
148 md_number_to_chars (*where
, headers
->header
.a_tload
, sizeof (headers
->header
.a_tload
));
149 *where
+= sizeof (headers
->header
.a_tload
);
150 md_number_to_chars (*where
, headers
->header
.a_dload
, sizeof (headers
->header
.a_dload
));
151 *where
+= sizeof (headers
->header
.a_dload
);
152 md_number_to_chars (*where
, headers
->header
.a_talign
, sizeof (headers
->header
.a_talign
));
153 *where
+= sizeof (headers
->header
.a_talign
);
154 md_number_to_chars (*where
, headers
->header
.a_dalign
, sizeof (headers
->header
.a_dalign
));
155 *where
+= sizeof (headers
->header
.a_dalign
);
156 md_number_to_chars (*where
, headers
->header
.a_balign
, sizeof (headers
->header
.a_balign
));
157 *where
+= sizeof (headers
->header
.a_balign
);
158 md_number_to_chars (*where
, headers
->header
.a_relaxable
, sizeof (headers
->header
.a_relaxable
));
159 *where
+= sizeof (headers
->header
.a_relaxable
);
160 #else /* ! CROSS_COMPILE */
161 append (where
, (char *) &headers
->header
, sizeof (headers
->header
));
162 #endif /* ! CROSS_COMPILE */
163 } /* a_header_append() */
166 obj_symbol_to_chars (where
, symbolP
)
170 md_number_to_chars ((char *) &(S_GET_OFFSET (symbolP
)), S_GET_OFFSET (symbolP
), sizeof (S_GET_OFFSET (symbolP
)));
171 md_number_to_chars ((char *) &(S_GET_DESC (symbolP
)), S_GET_DESC (symbolP
), sizeof (S_GET_DESC (symbolP
)));
172 md_number_to_chars ((char *) &symbolP
->sy_symbol
.n_value
, S_GET_VALUE (symbolP
), sizeof (symbolP
->sy_symbol
.n_value
));
174 append (where
, (char *) &symbolP
->sy_symbol
, sizeof (obj_symbol_type
));
175 } /* obj_symbol_to_chars() */
178 obj_emit_symbols (where
, symbol_rootP
)
180 symbolS
*symbol_rootP
;
185 * Emit all symbols left in the symbol chain.
187 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
189 /* Used to save the offset of the name. It is used to point
190 to the string in memory but must be a file offset. */
193 temp
= S_GET_NAME (symbolP
);
194 S_SET_OFFSET (symbolP
, symbolP
->sy_name_offset
);
196 /* Any symbol still undefined and is not a dbg symbol is made N_EXT. */
197 if (!S_IS_DEBUG (symbolP
) && !S_IS_DEFINED (symbolP
))
198 S_SET_EXTERNAL (symbolP
);
200 obj_symbol_to_chars (where
, symbolP
);
201 S_SET_NAME (symbolP
, temp
);
203 } /* emit_symbols() */
206 obj_symbol_new_hook (symbolP
)
209 S_SET_OTHER (symbolP
, 0);
210 S_SET_DESC (symbolP
, 0);
214 obj_bout_line (ignore
)
217 /* Assume delimiter is part of expression. */
218 /* BSD4.2 as fails with delightful bug, so we */
219 /* are not being incompatible here. */
220 new_logical_line ((char *) NULL
, (int) (get_absolute_expression ()));
221 demand_empty_rest_of_line ();
222 } /* obj_bout_line() */
225 obj_read_begin_hook ()
230 obj_crawl_symbol_chain (headers
)
231 object_headers
*headers
;
235 int symbol_number
= 0;
237 tc_crawl_symbol_chain (headers
);
239 symbolPP
= &symbol_rootP
; /*->last symbol chain link. */
240 while ((symbolP
= *symbolPP
) != NULL
)
242 if (flagseen
['R'] && (S_GET_SEGMENT (symbolP
) == SEG_DATA
))
244 S_SET_SEGMENT (symbolP
, SEG_TEXT
);
245 } /* if pusing data into text */
247 resolve_symbol_value (symbolP
);
249 /* OK, here is how we decide which symbols go out into the
250 brave new symtab. Symbols that do are:
252 * symbols with no name (stabd's?)
253 * symbols with debug info in their N_TYPE
255 Symbols that don't are:
256 * symbols that are registers
257 * symbols with \1 as their 3rd character (numeric labels)
258 * "local labels" as defined by S_LOCAL_NAME(name)
259 if the -L switch was passed to gas.
261 All other symbols are output. We complain if a deleted
262 symbol was marked external. */
266 && !S_IS_REGISTER (symbolP
)
267 && (!S_GET_NAME (symbolP
)
268 || S_IS_DEBUG (symbolP
)
270 /* FIXME-SOON this ifdef seems highly dubious to me. xoxorich. */
271 || !S_IS_DEFINED (symbolP
)
272 || S_IS_EXTERNAL (symbolP
)
274 || (S_GET_NAME (symbolP
)[0] != '\001' && (flagseen
['L'] || !S_LOCAL_NAME (symbolP
)))))
276 symbolP
->sy_number
= symbol_number
++;
278 /* The + 1 after strlen account for the \0 at the
279 end of each string */
280 if (!S_IS_STABD (symbolP
))
283 symbolP
->sy_name_offset
= string_byte_count
;
284 string_byte_count
+= strlen (S_GET_NAME (symbolP
)) + 1;
286 else /* .Stabd case. */
287 symbolP
->sy_name_offset
= 0;
288 symbolPP
= &(symbol_next (symbolP
));
292 if (S_IS_EXTERNAL (symbolP
) || !S_IS_DEFINED (symbolP
))
294 as_bad ("Local symbol %s never defined", S_GET_NAME (symbolP
));
297 /* Unhook it from the chain */
298 *symbolPP
= symbol_next (symbolP
);
299 } /* if this symbol should be in the output */
300 } /* for each symbol */
302 H_SET_SYMBOL_TABLE_SIZE (headers
, symbol_number
);
306 * Find strings by crawling along symbol table chain.
310 obj_emit_strings (where
)
316 /* Gotta do md_ byte-ordering stuff for string_byte_count first - KWK */
317 md_number_to_chars (*where
, string_byte_count
, sizeof (string_byte_count
));
318 *where
+= sizeof (string_byte_count
);
319 #else /* CROSS_COMPILE */
320 append (where
, (char *) &string_byte_count
, (unsigned long) sizeof (string_byte_count
));
321 #endif /* CROSS_COMPILE */
323 for (symbolP
= symbol_rootP
; symbolP
; symbolP
= symbol_next (symbolP
))
325 if (S_GET_NAME (symbolP
))
326 append (where
, S_GET_NAME (symbolP
), (unsigned long) (strlen (S_GET_NAME (symbolP
)) + 1));
327 } /* walk symbol chain */
330 /* end of obj-bout.c */