diff options
Diffstat (limited to 'bfd/doc/bfd.texinfo')
| -rw-r--r-- | bfd/doc/bfd.texinfo | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/bfd/doc/bfd.texinfo b/bfd/doc/bfd.texinfo new file mode 100644 index 0000000..eadf87c --- /dev/null +++ b/bfd/doc/bfd.texinfo @@ -0,0 +1,348 @@ +\input texinfo.tex +@setfilename bfd.info +@c $Id$ +@tex +% NOTE LOCAL KLUGE TO AVOID TOO MUCH WHITESPACE +\global\long\def\example{% +\begingroup +\let\aboveenvbreak=\par +\let\afterenvbreak=\par +\parskip=0pt +\lisp} +\global\long\def\Eexample{% +\Elisp +\endgroup +\vskip -\parskip% to cancel out effect of following \par +} +@end tex +@synindex fn cp + +@ifinfo +@format +START-INFO-DIR-ENTRY +* Bfd: (bfd). The Binary File Descriptor library. +END-INFO-DIR-ENTRY +@end format +@end ifinfo + +@ifinfo +This file documents the BFD library. + +Copyright (C) 1991 Free Software Foundation, Inc. + +Permission is granted to make and distribute verbatim copies of +this manual provided the copyright notice and this permission notice +are preserved on all copies. + +@ignore +Permission is granted to process this file through Tex and print the +results, provided the printed document carries copying permission +notice identical to this one except for the removal of this paragraph +(this paragraph not being relevant to the printed manual). + +@end ignore +Permission is granted to copy and distribute modified versions of this +manual under the conditions for verbatim copying, subject to the terms +of the GNU General Public License, which includes the provision that the +entire resulting derived work is distributed under the terms of a +permission notice identical to this one. + +Permission is granted to copy and distribute translations of this manual +into another language, under the above conditions for modified versions. +@end ifinfo +@iftex +@c@finalout +@setchapternewpage on +@c@setchapternewpage odd +@settitle LIB BFD, the Binary File Descriptor Library +@titlepage +@title{libbfd} +@subtitle{The Binary File Descriptor Library} +@sp 1 +@subtitle First Edition---BFD version < 3.0 +@subtitle April 1991 +@author {Steve Chamberlain} +@author {Cygnus Support} +@page + +@tex +\def\$#1${{#1}} % Kluge: collect RCS revision info without $...$ +\xdef\manvers{\$Revision$} % For use in headers, footers too +{\parskip=0pt +\hfill Cygnus Support\par +\hfill sac\@cygnus.com\par +\hfill {\it BFD}, \manvers\par +\hfill \TeX{}info \texinfoversion\par +} +\global\parindent=0pt % Steve likes it this way +@end tex + +@vskip 0pt plus 1filll +Copyright @copyright{} 1991 Free Software Foundation, Inc. + +Permission is granted to make and distribute verbatim copies of +this manual provided the copyright notice and this permission notice +are preserved on all copies. + +Permission is granted to copy and distribute modified versions of this +manual under the conditions for verbatim copying, subject to the terms +of the GNU General Public License, which includes the provision that the +entire resulting derived work is distributed under the terms of a +permission notice identical to this one. + +Permission is granted to copy and distribute translations of this manual +into another language, under the above conditions for modified versions. +@end titlepage +@end iftex + +@node Top, Overview, (dir), (dir) +@ifinfo +This file documents the binary file descriptor library libbfd. +@end ifinfo + +@menu +* Overview:: Overview of BFD +* BFD front end:: BFD front end +* BFD back ends:: BFD back ends +* Index:: Index +@end menu + +@node Overview, BFD front end, Top, Top +@chapter Introduction +@cindex BFD +@cindex what is it? +BFD is a package which allows applications to use the +same routines to operate on object files whatever the object file +format. A new object file format can be supported simply by +creating a new BFD back end and adding it to the library. + +BFD is split into two parts: the front end, and the back ends (one for +each object file format). +@itemize @bullet +@item The front end of BFD provides the interface to the user. It manages +memory and various canonical data structures. The front end also +decides which back end to use and when to call back end routines. +@item The back ends provide BFD its view of the real world. Each back +end provides a set of calls which the BFD front end can use to maintain +its canonical form. The back ends also may keep around information for +their own use, for greater efficiency. +@end itemize +@menu +* History:: History +* How It Works:: How It Works +* What BFD Version 2 Can Do:: What BFD Version 2 Can Do +@end menu + +@node History, How It Works, Overview, Overview +@section History + +One spur behind BFD was the desire, on the part of the GNU 960 team at +Intel Oregon, for interoperability of applications on their COFF and +b.out file formats. Cygnus was providing GNU support for the team, and +was contracted to provide the required functionality. + +The name came from a conversation David Wallace was having with Richard +Stallman about the library: RMS said that it would be quite hard---David +said ``BFD''. Stallman was right, but the name stuck. + +At the same time, Ready Systems wanted much the same thing, but for +different object file formats: IEEE-695, Oasys, Srecords, a.out and 68k +coff. + +BFD was first implemented by members of Cygnus Support; Steve +Chamberlain (@code{sac@@cygnus.com}), John Gilmore +(@code{gnu@@cygnus.com}), K. Richard Pixley (@code{rich@@cygnus.com}) +and David Henkel-Wallace (@code{gumby@@cygnus.com}). + + + +@node How It Works, What BFD Version 2 Can Do, History, Overview +@section How To Use BFD + +To use the library, include @file{bfd.h} and link with @file{libbfd.a}. + +BFD provides a common interface to the parts of an object file +for a calling application. + +When an application sucessfully opens a target file (object, archive, or +whatever), a pointer to an internal structure is returned. This pointer +points to a structure called @code{bfd}, described in +@file{bfd.h}. Our convention is to call this pointer a BFD, and +instances of it within code @code{abfd}. All operations on +the target object file are applied as methods to the BFD. The mapping is +defined within @code{bfd.h} in a set of macros, all beginning +with @samp{bfd_} to reduce namespace pollution. + +For example, this sequence does what you would probably expect: +return the number of sections in an object file attached to a BFD +@code{abfd}. + +@lisp +@c @cartouche +#include "bfd.h" + +unsigned int number_of_sections(abfd) +bfd *abfd; +@{ + return bfd_count_sections(abfd); +@} +@c @end cartouche +@end lisp + +The abstraction used within BFD is that an object file has: + +@itemize @bullet +@item +a header, +@item +a number of sections containing raw data (@pxref{Sections}), +@item +a set of relocations (@pxref{Relocations}), and +@item +some symbol information (@pxref{Symbols}). +@end itemize +@noindent +Also, BFDs opened for archives have the additional attribute of an index +and contain subordinate BFDs. This approach is fine for a.out and coff, +but loses efficiency when applied to formats such as S-records and +IEEE-695. + +@node What BFD Version 2 Can Do, , How It Works, Overview +@section What BFD Version 2 Can Do +@include bfdsumm.texi + +@node BFD front end, BFD back ends, Overview, Top +@chapter BFD front end +@include bfdt.texi + +@menu +* Memory Usage:: +* Initialization:: +* Sections:: +* Symbols:: +* Archives:: +* Formats:: +* Relocations:: +* Core Files:: +* Targets:: +* Architectures:: +* Opening and Closing:: +* Internal:: +* File Caching:: +* Linker Functions:: +* Hash Tables:: +@end menu + +@node Memory Usage, Initialization, BFD front end, BFD front end +@section Memory usage +BFD keeps all of its internal structures in obstacks. There is one obstack +per open BFD file, into which the current state is stored. When a BFD is +closed, the obstack is deleted, and so everything which has been +allocated by BFD for the closing file is thrown away. + +BFD does not free anything created by an application, but pointers into +@code{bfd} structures become invalid on a @code{bfd_close}; for example, +after a @code{bfd_close} the vector passed to +@code{bfd_canonicalize_symtab} is still around, since it has been +allocated by the application, but the data that it pointed to are +lost. + +The general rule is to not close a BFD until all operations dependent +upon data from the BFD have been completed, or all the data from within +the file has been copied. To help with the management of memory, there +is a function (@code{bfd_alloc_size}) which returns the number of bytes +in obstacks associated with the supplied BFD. This could be used to +select the greediest open BFD, close it to reclaim the memory, perform +some operation and reopen the BFD again, to get a fresh copy of the data +structures. + +@node Initialization, Sections, Memory Usage, BFD front end +@include init.texi + +@node Sections, Symbols, Initialization, BFD front end +@include section.texi + +@node Symbols, Archives, Sections, BFD front end +@include syms.texi + +@node Archives, Formats, Symbols, BFD front end +@include archive.texi + +@node Formats, Relocations, Archives, BFD front end +@include format.texi + +@node Relocations, Core Files, Formats, BFD front end +@include reloc.texi + +@node Core Files, Targets, Relocations, BFD front end +@include core.texi + +@node Targets, Architectures, Core Files, BFD front end +@include targets.texi + +@node Architectures, Opening and Closing, Targets, BFD front end +@include archures.texi + +@node Opening and Closing, Internal, Architectures, BFD front end +@include opncls.texi + +@node Internal, File Caching, Opening and Closing, BFD front end +@include libbfd.texi + +@node File Caching, Linker Functions, Internal, BFD front end +@include cache.texi + +@node Linker Functions, Hash Tables, File Caching, BFD front end +@include linker.texi + +@node Hash Tables, , Linker Functions, BFD front end +@include hash.texi + +@node BFD back ends, Index, BFD front end, Top +@chapter BFD back ends +@menu +* What to Put Where:: +* aout :: a.out backends +* coff :: coff backends +* elf :: elf backends +@ignore +* oasys :: oasys backends +* ieee :: ieee backend +* srecord :: s-record backend +@end ignore +@end menu +@node What to Put Where, aout, BFD back ends, BFD back ends +All of BFD lives in one directory. + +@node aout, coff, What to Put Where, BFD back ends +@include aoutx.texi + +@node coff, elf, aout, BFD back ends +@include coffcode.texi + +@node elf, , coff, BFD back ends +@include elf.texi +@c Leave this out until the file has some actual contents... +@c @include elfcode.texi + +@node Index, , BFD back ends , Top +@unnumbered Index +@printindex cp + +@tex +% I think something like @colophon should be in texinfo. In the +% meantime: +\long\def\colophon{\hbox to0pt{}\vfill +\centerline{The body of this manual is set in} +\centerline{\fontname\tenrm,} +\centerline{with headings in {\bf\fontname\tenbf}} +\centerline{and examples in {\tt\fontname\tentt}.} +\centerline{{\it\fontname\tenit\/} and} +\centerline{{\sl\fontname\tensl\/}} +\centerline{are used for emphasis.}\vfill} +\page\colophon +% Blame: doc@cygnus.com, 28mar91. +@end tex + +@contents +@bye |