Commit | Line | Data |
---|---|---|
252b5132 RH |
1 | \input texinfo.tex |
2 | @setfilename bfd.info | |
9553c638 AM |
3 | @c Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1997, 2000, |
4 | @c 2001, 2002, 2003 | |
7898deda NC |
5 | @c Free Software Foundation, Inc. |
6 | @c | |
252b5132 RH |
7 | @synindex fn cp |
8 | ||
9 | @ifinfo | |
10 | @format | |
11 | START-INFO-DIR-ENTRY | |
12 | * Bfd: (bfd). The Binary File Descriptor library. | |
13 | END-INFO-DIR-ENTRY | |
14 | @end format | |
15 | @end ifinfo | |
16 | ||
17 | @ifinfo | |
18 | This file documents the BFD library. | |
19 | ||
53954f5e | 20 | Copyright (C) 1991, 2000, 2001, 2003 Free Software Foundation, Inc. |
252b5132 | 21 | |
4a8e467a NC |
22 | Permission is granted to copy, distribute and/or modify this document |
23 | under the terms of the GNU Free Documentation License, Version 1.1 | |
24 | or any later version published by the Free Software Foundation; | |
25 | with no Invariant Sections, with no Front-Cover Texts, and with no | |
26 | Back-Cover Texts. A copy of the license is included in the | |
53954f5e | 27 | section entitled ``GNU Free Documentation License''. |
252b5132 RH |
28 | |
29 | @ignore | |
30 | Permission is granted to process this file through Tex and print the | |
31 | results, provided the printed document carries copying permission | |
32 | notice identical to this one except for the removal of this paragraph | |
33 | (this paragraph not being relevant to the printed manual). | |
34 | ||
35 | @end ignore | |
252b5132 RH |
36 | @end ifinfo |
37 | @iftex | |
38 | @c@finalout | |
39 | @setchapternewpage on | |
40 | @c@setchapternewpage odd | |
41 | @settitle LIB BFD, the Binary File Descriptor Library | |
42 | @titlepage | |
43 | @title{libbfd} | |
44 | @subtitle{The Binary File Descriptor Library} | |
45 | @sp 1 | |
07d8a891 NC |
46 | @subtitle First Edition---BFD version < 3.0 % Since no product is stable berfore version 3.0 :-) |
47 | @subtitle Original Document Created: April 1991 | |
252b5132 RH |
48 | @author {Steve Chamberlain} |
49 | @author {Cygnus Support} | |
50 | @page | |
51 | ||
52 | @tex | |
53 | \def\$#1${{#1}} % Kluge: collect RCS revision info without $...$ | |
27c5d6c9 | 54 | \xdef\manvers{1.5} % For use in headers, footers too |
252b5132 | 55 | {\parskip=0pt |
07d8a891 NC |
56 | \hfill Free Software Foundation\par |
57 | \hfill sac\@www.gnu.org\par | |
252b5132 RH |
58 | \hfill {\it BFD}, \manvers\par |
59 | \hfill \TeX{}info \texinfoversion\par | |
60 | } | |
61 | \global\parindent=0pt % Steve likes it this way | |
62 | @end tex | |
63 | ||
64 | @vskip 0pt plus 1filll | |
53954f5e | 65 | Copyright @copyright{} 1991, 2001, 2003 Free Software Foundation, Inc. |
252b5132 | 66 | |
4a8e467a NC |
67 | Permission is granted to copy, distribute and/or modify this document |
68 | under the terms of the GNU Free Documentation License, Version 1.1 | |
69 | or any later version published by the Free Software Foundation; | |
70 | with no Invariant Sections, with no Front-Cover Texts, and with no | |
71 | Back-Cover Texts. A copy of the license is included in the | |
53954f5e | 72 | section entitled ``GNU Free Documentation License''. |
252b5132 | 73 | |
252b5132 RH |
74 | @end titlepage |
75 | @end iftex | |
76 | ||
77 | @node Top, Overview, (dir), (dir) | |
78 | @ifinfo | |
79 | This file documents the binary file descriptor library libbfd. | |
80 | @end ifinfo | |
81 | ||
82 | @menu | |
83 | * Overview:: Overview of BFD | |
84 | * BFD front end:: BFD front end | |
85 | * BFD back ends:: BFD back ends | |
4a8e467a | 86 | * GNU Free Documentation License:: GNU Free Documentation License |
370b66a1 | 87 | * BFD Index:: BFD Index |
252b5132 RH |
88 | @end menu |
89 | ||
90 | @node Overview, BFD front end, Top, Top | |
91 | @chapter Introduction | |
92 | @cindex BFD | |
93 | @cindex what is it? | |
94 | BFD is a package which allows applications to use the | |
95 | same routines to operate on object files whatever the object file | |
96 | format. A new object file format can be supported simply by | |
97 | creating a new BFD back end and adding it to the library. | |
98 | ||
99 | BFD is split into two parts: the front end, and the back ends (one for | |
100 | each object file format). | |
101 | @itemize @bullet | |
102 | @item The front end of BFD provides the interface to the user. It manages | |
103 | memory and various canonical data structures. The front end also | |
104 | decides which back end to use and when to call back end routines. | |
105 | @item The back ends provide BFD its view of the real world. Each back | |
106 | end provides a set of calls which the BFD front end can use to maintain | |
107 | its canonical form. The back ends also may keep around information for | |
108 | their own use, for greater efficiency. | |
109 | @end itemize | |
110 | @menu | |
111 | * History:: History | |
112 | * How It Works:: How It Works | |
113 | * What BFD Version 2 Can Do:: What BFD Version 2 Can Do | |
114 | @end menu | |
115 | ||
116 | @node History, How It Works, Overview, Overview | |
117 | @section History | |
118 | ||
119 | One spur behind BFD was the desire, on the part of the GNU 960 team at | |
120 | Intel Oregon, for interoperability of applications on their COFF and | |
121 | b.out file formats. Cygnus was providing GNU support for the team, and | |
122 | was contracted to provide the required functionality. | |
123 | ||
124 | The name came from a conversation David Wallace was having with Richard | |
125 | Stallman about the library: RMS said that it would be quite hard---David | |
126 | said ``BFD''. Stallman was right, but the name stuck. | |
127 | ||
128 | At the same time, Ready Systems wanted much the same thing, but for | |
129 | different object file formats: IEEE-695, Oasys, Srecords, a.out and 68k | |
130 | coff. | |
131 | ||
132 | BFD was first implemented by members of Cygnus Support; Steve | |
133 | Chamberlain (@code{sac@@cygnus.com}), John Gilmore | |
134 | (@code{gnu@@cygnus.com}), K. Richard Pixley (@code{rich@@cygnus.com}) | |
135 | and David Henkel-Wallace (@code{gumby@@cygnus.com}). | |
136 | ||
137 | ||
138 | ||
139 | @node How It Works, What BFD Version 2 Can Do, History, Overview | |
140 | @section How To Use BFD | |
141 | ||
142 | To use the library, include @file{bfd.h} and link with @file{libbfd.a}. | |
143 | ||
144 | BFD provides a common interface to the parts of an object file | |
145 | for a calling application. | |
146 | ||
147 | When an application sucessfully opens a target file (object, archive, or | |
148 | whatever), a pointer to an internal structure is returned. This pointer | |
149 | points to a structure called @code{bfd}, described in | |
150 | @file{bfd.h}. Our convention is to call this pointer a BFD, and | |
151 | instances of it within code @code{abfd}. All operations on | |
152 | the target object file are applied as methods to the BFD. The mapping is | |
153 | defined within @code{bfd.h} in a set of macros, all beginning | |
154 | with @samp{bfd_} to reduce namespace pollution. | |
155 | ||
156 | For example, this sequence does what you would probably expect: | |
157 | return the number of sections in an object file attached to a BFD | |
158 | @code{abfd}. | |
159 | ||
53954f5e | 160 | @example |
252b5132 RH |
161 | @c @cartouche |
162 | #include "bfd.h" | |
163 | ||
53954f5e | 164 | unsigned int number_of_sections (abfd) |
252b5132 RH |
165 | bfd *abfd; |
166 | @{ | |
53954f5e | 167 | return bfd_count_sections (abfd); |
252b5132 RH |
168 | @} |
169 | @c @end cartouche | |
53954f5e | 170 | @end example |
252b5132 RH |
171 | |
172 | The abstraction used within BFD is that an object file has: | |
173 | ||
174 | @itemize @bullet | |
175 | @item | |
176 | a header, | |
177 | @item | |
178 | a number of sections containing raw data (@pxref{Sections}), | |
179 | @item | |
180 | a set of relocations (@pxref{Relocations}), and | |
181 | @item | |
182 | some symbol information (@pxref{Symbols}). | |
183 | @end itemize | |
184 | @noindent | |
185 | Also, BFDs opened for archives have the additional attribute of an index | |
186 | and contain subordinate BFDs. This approach is fine for a.out and coff, | |
187 | but loses efficiency when applied to formats such as S-records and | |
188 | IEEE-695. | |
189 | ||
190 | @node What BFD Version 2 Can Do, , How It Works, Overview | |
191 | @section What BFD Version 2 Can Do | |
192 | @include bfdsumm.texi | |
193 | ||
194 | @node BFD front end, BFD back ends, Overview, Top | |
53954f5e | 195 | @chapter BFD Front End |
252b5132 | 196 | @include bfdt.texi |
93509525 | 197 | @include bfdio.texi |
252b5132 RH |
198 | |
199 | @menu | |
200 | * Memory Usage:: | |
201 | * Initialization:: | |
202 | * Sections:: | |
203 | * Symbols:: | |
204 | * Archives:: | |
205 | * Formats:: | |
206 | * Relocations:: | |
207 | * Core Files:: | |
208 | * Targets:: | |
209 | * Architectures:: | |
210 | * Opening and Closing:: | |
211 | * Internal:: | |
212 | * File Caching:: | |
213 | * Linker Functions:: | |
214 | * Hash Tables:: | |
215 | @end menu | |
216 | ||
217 | @node Memory Usage, Initialization, BFD front end, BFD front end | |
53954f5e | 218 | @section Memory Usage |
252b5132 RH |
219 | BFD keeps all of its internal structures in obstacks. There is one obstack |
220 | per open BFD file, into which the current state is stored. When a BFD is | |
221 | closed, the obstack is deleted, and so everything which has been | |
222 | allocated by BFD for the closing file is thrown away. | |
223 | ||
224 | BFD does not free anything created by an application, but pointers into | |
225 | @code{bfd} structures become invalid on a @code{bfd_close}; for example, | |
226 | after a @code{bfd_close} the vector passed to | |
227 | @code{bfd_canonicalize_symtab} is still around, since it has been | |
228 | allocated by the application, but the data that it pointed to are | |
229 | lost. | |
230 | ||
231 | The general rule is to not close a BFD until all operations dependent | |
232 | upon data from the BFD have been completed, or all the data from within | |
233 | the file has been copied. To help with the management of memory, there | |
234 | is a function (@code{bfd_alloc_size}) which returns the number of bytes | |
235 | in obstacks associated with the supplied BFD. This could be used to | |
236 | select the greediest open BFD, close it to reclaim the memory, perform | |
237 | some operation and reopen the BFD again, to get a fresh copy of the data | |
238 | structures. | |
239 | ||
240 | @node Initialization, Sections, Memory Usage, BFD front end | |
241 | @include init.texi | |
242 | ||
243 | @node Sections, Symbols, Initialization, BFD front end | |
244 | @include section.texi | |
245 | ||
246 | @node Symbols, Archives, Sections, BFD front end | |
247 | @include syms.texi | |
248 | ||
249 | @node Archives, Formats, Symbols, BFD front end | |
250 | @include archive.texi | |
251 | ||
252 | @node Formats, Relocations, Archives, BFD front end | |
253 | @include format.texi | |
254 | ||
255 | @node Relocations, Core Files, Formats, BFD front end | |
256 | @include reloc.texi | |
257 | ||
258 | @node Core Files, Targets, Relocations, BFD front end | |
259 | @include core.texi | |
260 | ||
261 | @node Targets, Architectures, Core Files, BFD front end | |
262 | @include targets.texi | |
263 | ||
264 | @node Architectures, Opening and Closing, Targets, BFD front end | |
265 | @include archures.texi | |
266 | ||
267 | @node Opening and Closing, Internal, Architectures, BFD front end | |
268 | @include opncls.texi | |
269 | ||
270 | @node Internal, File Caching, Opening and Closing, BFD front end | |
271 | @include libbfd.texi | |
272 | ||
273 | @node File Caching, Linker Functions, Internal, BFD front end | |
274 | @include cache.texi | |
275 | ||
276 | @node Linker Functions, Hash Tables, File Caching, BFD front end | |
277 | @include linker.texi | |
278 | ||
279 | @node Hash Tables, , Linker Functions, BFD front end | |
280 | @include hash.texi | |
281 | ||
4a8e467a | 282 | @node BFD back ends, GNU Free Documentation License, BFD front end, Top |
252b5132 RH |
283 | @chapter BFD back ends |
284 | @menu | |
285 | * What to Put Where:: | |
286 | * aout :: a.out backends | |
287 | * coff :: coff backends | |
288 | * elf :: elf backends | |
3c3bdf30 | 289 | * mmo :: mmo backend |
252b5132 RH |
290 | @ignore |
291 | * oasys :: oasys backends | |
292 | * ieee :: ieee backend | |
293 | * srecord :: s-record backend | |
294 | @end ignore | |
295 | @end menu | |
296 | @node What to Put Where, aout, BFD back ends, BFD back ends | |
9cd73268 | 297 | @section What to Put Where |
252b5132 RH |
298 | All of BFD lives in one directory. |
299 | ||
300 | @node aout, coff, What to Put Where, BFD back ends | |
301 | @include aoutx.texi | |
302 | ||
303 | @node coff, elf, aout, BFD back ends | |
304 | @include coffcode.texi | |
305 | ||
3c3bdf30 | 306 | @node elf, mmo, coff, BFD back ends |
252b5132 RH |
307 | @include elf.texi |
308 | @c Leave this out until the file has some actual contents... | |
309 | @c @include elfcode.texi | |
310 | ||
3c3bdf30 NC |
311 | @node mmo, , elf, BFD back ends |
312 | @include mmo.texi | |
313 | ||
370b66a1 | 314 | @node GNU Free Documentation License, BFD Index, BFD back ends, Top |
53954f5e NC |
315 | @include fdl.texi |
316 | ||
370b66a1 CD |
317 | @node BFD Index, , GNU Free Documentation License, Top |
318 | @unnumbered BFD Index | |
252b5132 RH |
319 | @printindex cp |
320 | ||
321 | @tex | |
322 | % I think something like @colophon should be in texinfo. In the | |
323 | % meantime: | |
324 | \long\def\colophon{\hbox to0pt{}\vfill | |
325 | \centerline{The body of this manual is set in} | |
326 | \centerline{\fontname\tenrm,} | |
327 | \centerline{with headings in {\bf\fontname\tenbf}} | |
328 | \centerline{and examples in {\tt\fontname\tentt}.} | |
329 | \centerline{{\it\fontname\tenit\/} and} | |
330 | \centerline{{\sl\fontname\tensl\/}} | |
331 | \centerline{are used for emphasis.}\vfill} | |
332 | \page\colophon | |
333 | % Blame: doc@cygnus.com, 28mar91. | |
334 | @end tex | |
335 | ||
336 | @contents | |
337 | @bye |