2670 lines
88 KiB
Plaintext
2670 lines
88 KiB
Plaintext
\input texinfo
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@setfilename gdbint.info
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@c $Id: gdbint.texinfo,v 1.76 1994/07/17 21:17:18 shebs Exp $
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@ifinfo
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@format
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START-INFO-DIR-ENTRY
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* Gdb-Internals: (gdbint). The GNU debugger's internals.
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END-INFO-DIR-ENTRY
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@end format
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@end ifinfo
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@ifinfo
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This file documents the internals of the GNU debugger GDB.
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Copyright 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
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Contributed by Cygnus Support. Written by John Gilmore.
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Permission is granted to make and distribute verbatim copies of
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this manual provided the copyright notice and this permission notice
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are preserved on all copies.
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@ignore
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Permission is granted to process this file through Tex and print the
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results, provided the printed document carries copying permission
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notice identical to this one except for the removal of this paragraph
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(this paragraph not being relevant to the printed manual).
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@end ignore
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Permission is granted to copy or distribute modified versions of this
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manual under the terms of the GPL (for which purpose this text may be
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regarded as a program in the language TeX).
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@end ifinfo
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@setchapternewpage off
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@settitle GDB Internals
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@titlepage
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@title{Working in GDB}
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@subtitle{A guide to the internals of the GNU debugger}
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@author John Gilmore
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@author Cygnus Support
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@page
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@tex
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\def\$#1${{#1}} % Kluge: collect RCS revision info without $...$
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\xdef\manvers{\$Revision: 1.76 $} % For use in headers, footers too
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{\parskip=0pt
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\hfill Cygnus Support\par
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\hfill \manvers\par
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\hfill \TeX{}info \texinfoversion\par
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}
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@end tex
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@vskip 0pt plus 1filll
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Copyright @copyright{} 1990, 1991, 1992, 1993, 1994 Free Software Foundation, Inc.
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Permission is granted to make and distribute verbatim copies of
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this manual provided the copyright notice and this permission notice
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are preserved on all copies.
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@end titlepage
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@node Top
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@c Perhaps this should be the title of the document (but only for info,
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@c not for TeX). Existing GNU manuals seem inconsistent on this point.
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@top Scope of this Document
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This document documents the internals of the GNU debugger, GDB. It is
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intended to document aspects of GDB which apply across many different
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parts of GDB (for example, @pxref{Coding Style}), or which are global
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aspects of design (for example, what are the major modules and which
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files document them in detail?). Information which pertains to specific
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data structures, functions, variables, etc., should be put in comments
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in the source code, not here. It is more likely to get noticed and kept
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up to date there. Some of the information in this document should
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probably be moved into comments.
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@menu
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* README:: The README File
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* Getting Started:: Getting started working on GDB
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* Debugging GDB:: Debugging GDB with itself
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* New Architectures:: Defining a New Host or Target Architecture
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* Config:: Adding a New Configuration
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* Host:: Adding a New Host
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* Native:: Adding a New Native Configuration
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* Target:: Adding a New Target
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* Languages:: Defining New Source Languages
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* Releases:: Configuring GDB for Release
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* Partial Symbol Tables:: How GDB reads symbols quickly at startup
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* Types:: How GDB keeps track of types
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* BFD support for GDB:: How BFD and GDB interface
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* Symbol Reading:: Defining New Symbol Readers
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* Cleanups:: Cleanups
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* Wrapping:: Wrapping Output Lines
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* Frames:: Keeping track of function calls
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* Remote Stubs:: Code that runs in targets and talks to GDB
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* Longjmp Support:: Stepping through longjmp's in the target
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* Coding Style:: Strunk and White for GDB maintainers
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* Clean Design:: Frank Lloyd Wright for GDB maintainers
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* Submitting Patches:: How to get your changes into GDB releases
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* Host Conditionals:: What features exist in the host
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* Target Conditionals:: What features exist in the target
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* Native Conditionals:: Conditionals for when host and target are same
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* Obsolete Conditionals:: Conditionals that don't exist any more
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* XCOFF:: The Object file format used on IBM's RS/6000
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@end menu
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@node README
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@chapter The @file{README} File
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Check the @file{README} file, it often has useful information that does not
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appear anywhere else in the directory.
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@node Getting Started
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@chapter Getting Started Working on GDB
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GDB is a large and complicated program, and if you first starting to
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work on it, it can be hard to know where to start. Fortunately, if you
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know how to go about it, there are ways to figure out what is going on:
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@itemize @bullet
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@item
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This manual, the GDB Internals manual, has information which applies
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generally to many parts of GDB.
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@item
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Information about particular functions or data structures are located in
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comments with those functions or data structures. If you run across a
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function or a global variable which does not have a comment correctly
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explaining what is does, this can be thought of as a bug in GDB; feel
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free to submit a bug report, with a suggested comment if you can figure
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out what the comment should say (@pxref{Submitting Patches}). If you
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find a comment which is actually wrong, be especially sure to report that.
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Comments explaining the function of macros defined in host, target, or
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native dependent files can be in several places. Sometimes they are
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repeated every place the macro is defined. Sometimes they are where the
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macro is used. Sometimes there is a header file which supplies a
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default definition of the macro, and the comment is there. This manual
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also has a list of macros (@pxref{Host Conditionals}, @pxref{Target
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Conditionals}, @pxref{Native Conditionals}, and @pxref{Obsolete
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Conditionals}) with some documentation.
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@item
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Start with the header files. Once you some idea of how GDB's internal
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symbol tables are stored (see @file{symtab.h}, @file{gdbtypes.h}), you
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will find it much easier to understand the code which uses and creates
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those symbol tables.
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@item
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You may wish to process the information you are getting somehow, to
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enhance your understanding of it. Summarize it, translate it to another
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language, add some (perhaps trivial or non-useful) feature to GDB, use
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the code to predict what a test case would do and write the test case
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and verify your prediction, etc. If you are reading code and your eyes
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are starting to glaze over, this is a sign you need to use a more active
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approach.
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@item
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Once you have a part of GDB to start with, you can find more
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specifically the part you are looking for by stepping through each
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function with the @code{next} command. Do not use @code{step} or you
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will quickly get distracted; when the function you are stepping through
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calls another function try only to get a big-picture understanding
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(perhaps using the comment at the beginning of the function being
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called) of what it does. This way you can identify which of the
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functions being called by the function you are stepping through is the
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one which you are interested in. You may need to examine the data
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structures generated at each stage, with reference to the comments in
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the header files explaining what the data structures are supposed to
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look like.
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Of course, this same technique can be used if you are just reading the
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code, rather than actually stepping through it. The same general
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principle applies---when the code you are looking at calls something
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else, just try to understand generally what the code being called does,
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rather than worrying about all its details.
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@item
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A good place to start when tracking down some particular area is with a
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command which invokes that feature. Suppose you want to know how
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single-stepping works. As a GDB user, you know that the @code{step}
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command invokes single-stepping. The command is invoked via command
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tables (see @file{command.h}); by convention the function which actually
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performs the command is formed by taking the name of the command and
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adding @samp{_command}, or in the case of an @code{info} subcommand,
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@samp{_info}. For example, the @code{step} command invokes the
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@code{step_command} function and the @code{info display} command invokes
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@code{display_info}. When this convention is not followed, you might
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have to use @code{grep} or @kbd{M-x tags-search} in emacs, or run GDB on
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itself and set a breakpoint in @code{execute_command}.
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@item
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If all of the above fail, it may be appropriate to ask for information
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on @code{bug-gdb}. But @emph{never} post a generic question like ``I was
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wondering if anyone could give me some tips about understanding
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GDB''---if we had some magic secret we would put it in this manual.
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Suggestions for improving the manual are always welcome, of course.
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@end itemize
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Good luck!
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@node Debugging GDB
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@chapter Debugging GDB with itself
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If GDB is limping on your machine, this is the preferred way to get it
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fully functional. Be warned that in some ancient Unix systems, like
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Ultrix 4.2, a program can't be running in one process while it is being
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debugged in another. Rather than typing the command @code{@w{./gdb
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./gdb}}, which works on Suns and such, you can copy @file{gdb} to
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@file{gdb2} and then type @code{@w{./gdb ./gdb2}}.
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When you run GDB in the GDB source directory, it will read a
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@file{.gdbinit} file that sets up some simple things to make debugging
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gdb easier. The @code{info} command, when executed without a subcommand
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in a GDB being debugged by gdb, will pop you back up to the top level
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gdb. See @file{.gdbinit} for details.
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If you use emacs, you will probably want to do a @code{make TAGS} after
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you configure your distribution; this will put the machine dependent
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routines for your local machine where they will be accessed first by
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@kbd{M-.}
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Also, make sure that you've either compiled GDB with your local cc, or
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have run @code{fixincludes} if you are compiling with gcc.
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@node New Architectures
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@chapter Defining a New Host or Target Architecture
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When building support for a new host and/or target, much of the work you
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need to do is handled by specifying configuration files;
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@pxref{Config,,Adding a New Configuration}. Further work can be
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divided into ``host-dependent'' (@pxref{Host,,Adding a New Host}) and
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``target-dependent'' (@pxref{Target,,Adding a New Target}). The
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following discussion is meant to explain the difference between hosts
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and targets.
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@heading What is considered ``host-dependent'' versus ``target-dependent''?
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@dfn{Host} refers to attributes of the system where GDB runs.
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@dfn{Target} refers to the system where the program being debugged
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executes. In most cases they are the same machine, in which case
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a third type of @dfn{Native} attributes come into play.
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Defines and include files needed to build on the host are host support.
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Examples are tty support, system defined types, host byte order, host
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float format.
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Defines and information needed to handle the target format are target
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dependent. Examples are the stack frame format, instruction set,
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breakpoint instruction, registers, and how to set up and tear down the stack
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to call a function.
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Information that is only needed when the host and target are the same,
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is native dependent. One example is Unix child process support; if the
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host and target are not the same, doing a fork to start the target
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process is a bad idea. The various macros needed for finding the
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registers in the @code{upage}, running @code{ptrace}, and such are all in the
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native-dependent files.
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Another example of native-dependent code is support for features
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that are really part of the target environment, but which require
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@code{#include} files that are only available on the host system.
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Core file handling and @code{setjmp} handling are two common cases.
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When you want to make GDB work ``native'' on a particular
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machine, you have to include all three kinds of information.
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The dependent information in GDB is organized into files by naming
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conventions.
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Host-Dependent Files
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@table @file
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@item config/*/*.mh
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Sets Makefile parameters
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@item config/*/xm-*.h
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Global #include's and #define's and definitions
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@item *-xdep.c
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Global variables and functions
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@end table
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Native-Dependent Files
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@table @file
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@item config/*/*.mh
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Sets Makefile parameters (for @emph{both} host and native)
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@item config/*/nm-*.h
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#include's and #define's and definitions. This file
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is only included by the small number of modules that need it,
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so beware of doing feature-test #define's from its macros.
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@item *-nat.c
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global variables and functions
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@end table
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Target-Dependent Files
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@table @file
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@item config/*/*.mt
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Sets Makefile parameters
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@item config/*/tm-*.h
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Global #include's and #define's and definitions
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@item *-tdep.c
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Global variables and functions
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@end table
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At this writing, most supported hosts have had their host and native
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dependencies sorted out properly. There are a few stragglers, which
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can be recognized by the absence of NATDEPFILES lines in their
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@file{config/*/*.mh}.
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@node Config
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@chapter Adding a New Configuration
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Most of the work in making GDB compile on a new machine is in specifying
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the configuration of the machine. This is done in a dizzying variety of
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header files and configuration scripts, which we hope to make more
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sensible soon. Let's say your new host is called an @var{xxx} (e.g.
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@samp{sun4}), and its full three-part configuration name is
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@code{@var{xarch}-@var{xvend}-@var{xos}} (e.g. @samp{sparc-sun-sunos4}). In
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particular:
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In the top level directory, edit @file{config.sub} and add @var{xarch},
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@var{xvend}, and @var{xos} to the lists of supported architectures,
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vendors, and operating systems near the bottom of the file. Also, add
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@var{xxx} as an alias that maps to
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@code{@var{xarch}-@var{xvend}-@var{xos}}. You can test your changes by
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running
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@example
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./config.sub @var{xxx}
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@end example
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@noindent
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and
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@example
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./config.sub @code{@var{xarch}-@var{xvend}-@var{xos}}
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@end example
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@noindent
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which should both respond with @code{@var{xarch}-@var{xvend}-@var{xos}}
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and no error messages.
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Now, go to the @file{bfd} directory and
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create a new file @file{bfd/hosts/h-@var{xxx}.h}. Examine the
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other @file{h-*.h} files as templates, and create one that brings in the
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right include files for your system, and defines any host-specific
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macros needed by BFD, the Binutils, GNU LD, or the Opcodes directories.
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(They all share the bfd @file{hosts} directory and the @file{configure.host}
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file.)
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Then edit @file{bfd/configure.host}. Add a line to recognize your
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@code{@var{xarch}-@var{xvend}-@var{xos}} configuration, and set
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@code{my_host} to @var{xxx} when you recognize it. This will cause your
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file @file{h-@var{xxx}.h} to be linked to @file{sysdep.h} at configuration
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time. When creating the line that recognizes your configuration,
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only match the fields that you really need to match; e.g. don't
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match the architecture or manufacturer if the OS is sufficient
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to distinguish the configuration that your @file{h-@var{xxx}.h} file supports.
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Don't match the manufacturer name unless you really need to.
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This should make future ports easier.
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Also, if this host requires any changes to the Makefile, create a file
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@file{bfd/config/@var{xxx}.mh}, which includes the required lines.
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It's possible that the @file{libiberty} and @file{readline} directories
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won't need any changes for your configuration, but if they do, you can
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change the @file{configure.in} file there to recognize your system and
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map to an @file{mh-@var{xxx}} file. Then add @file{mh-@var{xxx}}
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to the @file{config/} subdirectory, to set any makefile variables you
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need. The only current options in there are things like @samp{-DSYSV}.
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(This @file{mh-@var{xxx}} naming convention differs from elsewhere
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in GDB, by historical accident. It should be cleaned up so that all
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such files are called @file{@var{xxx}.mh}.)
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Aha! Now to configure GDB itself! Edit
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@file{gdb/configure.in} to recognize your system and set @code{gdb_host}
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to @var{xxx}, and (unless your desired target is already available) also
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set @code{gdb_target} to something appropriate (for instance,
|
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@var{xxx}). To handle new hosts, modify the segment after the comment
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@samp{# per-host}; to handle new targets, modify after @samp{#
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per-target}.
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@c Would it be simpler to just use different per-host and per-target
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@c *scripts*, and call them from {configure} ?
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|
Finally, you'll need to specify and define GDB's host-, native-, and
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target-dependent @file{.h} and @file{.c} files used for your
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configuration; the next two chapters discuss those.
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|
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@node Host
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@chapter Adding a New Host
|
|
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|
Once you have specified a new configuration for your host
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(@pxref{Config,,Adding a New Configuration}), there are three remaining
|
|
pieces to making GDB work on a new machine. First, you have to make it
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host on the new machine (compile there, handle that machine's terminals
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|
properly, etc). If you will be cross-debugging to some other kind of
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|
system that's already supported, you are done.
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|
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|
If you want to use GDB to debug programs that run on the new machine,
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|
you have to get it to understand the machine's object files, symbol
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|
files, and interfaces to processes; @pxref{Target,,Adding a New Target}
|
|
and @pxref{Native,,Adding a New Native Configuration}
|
|
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|
Several files control GDB's configuration for host systems:
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|
@table @file
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@item gdb/config/@var{arch}/@var{xxx}.mh
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Specifies Makefile fragments needed when hosting on machine @var{xxx}.
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|
In particular, this lists the required machine-dependent object files,
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by defining @samp{XDEPFILES=@dots{}}. Also
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specifies the header file which describes host @var{xxx}, by defining
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@code{XM_FILE= xm-@var{xxx}.h}. You can also define @code{CC},
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@code{REGEX} and @code{REGEX1}, @code{SYSV_DEFINE}, @code{XM_CFLAGS},
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@code{XM_ADD_FILES}, @code{XM_CLIBS}, @code{XM_CDEPS},
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etc.; see @file{Makefile.in}.
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@item gdb/config/@var{arch}/xm-@var{xxx}.h
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(@file{xm.h} is a link to this file, created by configure).
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|
Contains C macro definitions describing the host system environment,
|
|
such as byte order, host C compiler and library, ptrace support,
|
|
and core file structure. Crib from existing @file{xm-*.h} files
|
|
to create a new one.
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@item gdb/@var{xxx}-xdep.c
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Contains any miscellaneous C code required for this machine
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as a host. On many machines it doesn't exist at all. If it does
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exist, put @file{@var{xxx}-xdep.o} into the @code{XDEPFILES} line
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in @file{gdb/config/mh-@var{xxx}}.
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@end table
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@subheading Generic Host Support Files
|
|
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|
There are some ``generic'' versions of routines that can be used by
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|
various systems. These can be customized in various ways by macros
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|
defined in your @file{xm-@var{xxx}.h} file. If these routines work for
|
|
the @var{xxx} host, you can just include the generic file's name (with
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@samp{.o}, not @samp{.c}) in @code{XDEPFILES}.
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|
Otherwise, if your machine needs custom support routines, you will need
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|
to write routines that perform the same functions as the generic file.
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|
Put them into @code{@var{xxx}-xdep.c}, and put @code{@var{xxx}-xdep.o}
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into @code{XDEPFILES}.
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@table @file
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|
@item ser-bsd.c
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|
This contains serial line support for Berkeley-derived Unix systems.
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|
@item ser-go32.c
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|
This contains serial line support for 32-bit programs running under DOS
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|
using the GO32 execution environment.
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|
@item ser-termios.c
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|
This contains serial line support for System V-derived Unix systems.
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@end table
|
|
|
|
Now, you are now ready to try configuring GDB to compile using your system
|
|
as its host. From the top level (above @file{bfd}, @file{gdb}, etc), do:
|
|
|
|
@example
|
|
./configure @var{xxx} --target=vxworks960
|
|
@end example
|
|
|
|
This will configure your system to cross-compile for VxWorks on
|
|
the Intel 960, which is probably not what you really want, but it's
|
|
a test case that works at this stage. (You haven't set up to be
|
|
able to debug programs that run @emph{on} @var{xxx} yet.)
|
|
|
|
If this succeeds, you can try building it all with:
|
|
|
|
@example
|
|
make
|
|
@end example
|
|
|
|
Repeat until the program configures, compiles, links, and runs.
|
|
When run, it won't be able to do much (unless you have a VxWorks/960
|
|
board on your network) but you will know that the host support is
|
|
pretty well done.
|
|
|
|
Good luck! Comments and suggestions about this section are particularly
|
|
welcome; send them to @samp{bug-gdb@@prep.ai.mit.edu}.
|
|
|
|
@node Native
|
|
@chapter Adding a New Native Configuration
|
|
|
|
If you are making GDB run native on the @var{xxx} machine, you have
|
|
plenty more work to do. Several files control GDB's configuration for
|
|
native support:
|
|
|
|
@table @file
|
|
@item gdb/config/@var{xarch}/@var{xxx}.mh
|
|
Specifies Makefile fragments needed when hosting @emph{or native}
|
|
on machine @var{xxx}.
|
|
In particular, this lists the required native-dependent object files,
|
|
by defining @samp{NATDEPFILES=@dots{}}. Also
|
|
specifies the header file which describes native support on @var{xxx},
|
|
by defining @samp{NAT_FILE= nm-@var{xxx}.h}.
|
|
You can also define @samp{NAT_CFLAGS},
|
|
@samp{NAT_ADD_FILES}, @samp{NAT_CLIBS}, @samp{NAT_CDEPS},
|
|
etc.; see @file{Makefile.in}.
|
|
|
|
@item gdb/config/@var{arch}/nm-@var{xxx}.h
|
|
(@file{nm.h} is a link to this file, created by configure).
|
|
Contains C macro definitions describing the native system environment,
|
|
such as child process control and core file support.
|
|
Crib from existing @file{nm-*.h} files to create a new one.
|
|
|
|
@item gdb/@var{xxx}-nat.c
|
|
Contains any miscellaneous C code required for this native support
|
|
of this machine. On some machines it doesn't exist at all.
|
|
@end table
|
|
|
|
@subheading Generic Native Support Files
|
|
|
|
There are some ``generic'' versions of routines that can be used by
|
|
various systems. These can be customized in various ways by macros
|
|
defined in your @file{nm-@var{xxx}.h} file. If these routines work for
|
|
the @var{xxx} host, you can just include the generic file's name (with
|
|
@samp{.o}, not @samp{.c}) in @code{NATDEPFILES}.
|
|
|
|
Otherwise, if your machine needs custom support routines, you will need
|
|
to write routines that perform the same functions as the generic file.
|
|
Put them into @code{@var{xxx}-nat.c}, and put @code{@var{xxx}-nat.o}
|
|
into @code{NATDEPFILES}.
|
|
|
|
@table @file
|
|
|
|
@item inftarg.c
|
|
This contains the @emph{target_ops vector} that supports Unix child
|
|
processes on systems which use ptrace and wait to control the child.
|
|
|
|
@item procfs.c
|
|
This contains the @emph{target_ops vector} that supports Unix child
|
|
processes on systems which use /proc to control the child.
|
|
|
|
@item fork-child.c
|
|
This does the low-level grunge that uses Unix system calls
|
|
to do a "fork and exec" to start up a child process.
|
|
|
|
@item infptrace.c
|
|
This is the low level interface to inferior processes for systems
|
|
using the Unix @code{ptrace} call in a vanilla way.
|
|
|
|
@item coredep.c::fetch_core_registers()
|
|
Support for reading registers out of a core file. This routine calls
|
|
@code{register_addr()}, see below.
|
|
Now that BFD is used to read core files, virtually all machines should
|
|
use @code{coredep.c}, and should just provide @code{fetch_core_registers} in
|
|
@code{@var{xxx}-nat.c} (or @code{REGISTER_U_ADDR} in @code{nm-@var{xxx}.h}).
|
|
|
|
@item coredep.c::register_addr()
|
|
If your @code{nm-@var{xxx}.h} file defines the macro
|
|
@code{REGISTER_U_ADDR(addr, blockend, regno)}, it should be defined to
|
|
set @code{addr} to the offset within the @samp{user}
|
|
struct of GDB register number @code{regno}. @code{blockend} is the
|
|
offset within the ``upage'' of @code{u.u_ar0}.
|
|
If @code{REGISTER_U_ADDR} is defined,
|
|
@file{coredep.c} will define the @code{register_addr()} function and use
|
|
the macro in it. If you do not define @code{REGISTER_U_ADDR}, but you
|
|
are using the standard @code{fetch_core_registers()}, you will need to
|
|
define your own version of @code{register_addr()}, put it into your
|
|
@code{@var{xxx}-nat.c} file, and be sure @code{@var{xxx}-nat.o} is in
|
|
the @code{NATDEPFILES} list. If you have your own
|
|
@code{fetch_core_registers()}, you may not need a separate
|
|
@code{register_addr()}. Many custom @code{fetch_core_registers()}
|
|
implementations simply locate the registers themselves.@refill
|
|
@end table
|
|
|
|
When making GDB run native on a new operating system,
|
|
to make it possible to debug
|
|
core files, you will need to either write specific code for parsing your
|
|
OS's core files, or customize @file{bfd/trad-core.c}. First, use
|
|
whatever @code{#include} files your machine uses to define the struct of
|
|
registers that is accessible (possibly in the u-area) in a core file
|
|
(rather than @file{machine/reg.h}), and an include file that defines whatever
|
|
header exists on a core file (e.g. the u-area or a @samp{struct core}). Then
|
|
modify @code{trad_unix_core_file_p()} to use these values to set up the
|
|
section information for the data segment, stack segment, any other
|
|
segments in the core file (perhaps shared library contents or control
|
|
information), ``registers'' segment, and if there are two discontiguous
|
|
sets of registers (e.g. integer and float), the ``reg2'' segment. This
|
|
section information basically delimits areas in the core file in a
|
|
standard way, which the section-reading routines in BFD know how to seek
|
|
around in.
|
|
|
|
Then back in GDB, you need a matching routine called
|
|
@code{fetch_core_registers()}. If you can use the generic one, it's in
|
|
@file{coredep.c}; if not, it's in your @file{@var{xxx}-nat.c} file.
|
|
It will be passed a char pointer to the entire ``registers'' segment,
|
|
its length, and a zero; or a char pointer to the entire ``regs2''
|
|
segment, its length, and a 2. The routine should suck out the supplied
|
|
register values and install them into GDB's ``registers'' array.
|
|
(@xref{New Architectures,,Defining a New Host or Target Architecture},
|
|
for more info about this.)
|
|
|
|
If your system uses @file{/proc} to control processes, and uses ELF
|
|
format core files, then you may be able to use the same routines
|
|
for reading the registers out of processes and out of core files.
|
|
|
|
@node Target
|
|
@chapter Adding a New Target
|
|
|
|
For a new target called @var{ttt}, first specify the configuration as
|
|
described in @ref{Config,,Adding a New Configuration}. If your new
|
|
target is the same as your new host, you've probably already done that.
|
|
|
|
A variety of files specify attributes of the GDB target environment:
|
|
|
|
@table @file
|
|
@item gdb/config/@var{arch}/@var{ttt}.mt
|
|
Contains a Makefile fragment specific to this target.
|
|
Specifies what object files are needed for target @var{ttt}, by
|
|
defining @samp{TDEPFILES=@dots{}}.
|
|
Also specifies the header file which describes @var{ttt}, by defining
|
|
@samp{TM_FILE= tm-@var{ttt}.h}. You can also define @samp{TM_CFLAGS},
|
|
@samp{TM_CLIBS}, @samp{TM_CDEPS},
|
|
and other Makefile variables here; see @file{Makefile.in}.
|
|
|
|
@item gdb/config/@var{arch}/tm-@var{ttt}.h
|
|
(@file{tm.h} is a link to this file, created by configure).
|
|
Contains macro definitions about the target machine's
|
|
registers, stack frame format and instructions.
|
|
Crib from existing @file{tm-*.h} files when building a new one.
|
|
|
|
@item gdb/@var{ttt}-tdep.c
|
|
Contains any miscellaneous code required for this target machine.
|
|
On some machines it doesn't exist at all. Sometimes the macros
|
|
in @file{tm-@var{ttt}.h} become very complicated, so they are
|
|
implemented as functions here instead, and the macro is simply
|
|
defined to call the function.
|
|
|
|
@item gdb/exec.c
|
|
Defines functions for accessing files that are
|
|
executable on the target system. These functions open and examine an
|
|
exec file, extract data from one, write data to one, print information
|
|
about one, etc. Now that executable files are handled with BFD, every
|
|
target should be able to use the generic exec.c rather than its
|
|
own custom code.
|
|
|
|
@item gdb/@var{arch}-pinsn.c
|
|
Prints (disassembles) the target machine's instructions.
|
|
This file is usually shared with other target machines which use the
|
|
same processor, which is why it is @file{@var{arch}-pinsn.c} rather
|
|
than @file{@var{ttt}-pinsn.c}.
|
|
|
|
@item gdb/@var{arch}-opcode.h
|
|
Contains some large initialized
|
|
data structures describing the target machine's instructions.
|
|
This is a bit strange for a @file{.h} file, but it's OK since
|
|
it is only included in one place. @file{@var{arch}-opcode.h} is shared
|
|
between the debugger and the assembler, if the GNU assembler has been
|
|
ported to the target machine.
|
|
|
|
@item gdb/config/@var{arch}/tm-@var{arch}.h
|
|
This often exists to describe the basic layout of the target machine's
|
|
processor chip (registers, stack, etc).
|
|
If used, it is included by @file{tm-@var{xxx}.h}. It can
|
|
be shared among many targets that use the same processor.
|
|
|
|
@item gdb/@var{arch}-tdep.c
|
|
Similarly, there are often common subroutines that are shared by all
|
|
target machines that use this particular architecture.
|
|
@end table
|
|
|
|
When adding support for a new target machine, there are various areas
|
|
of support that might need change, or might be OK.
|
|
|
|
If you are using an existing object file format (a.out or COFF),
|
|
there is probably little to be done. See @file{bfd/doc/bfd.texinfo}
|
|
for more information on writing new a.out or COFF versions.
|
|
|
|
If you need to add a new object file format, you must first add it to
|
|
BFD. This is beyond the scope of this document right now. Basically
|
|
you must build a transfer vector (of type @code{bfd_target}), which will
|
|
mean writing all the required routines, and add it to the list in
|
|
@file{bfd/targets.c}.
|
|
|
|
You must then arrange for the BFD code to provide access to the
|
|
debugging symbols. Generally GDB will have to call swapping routines
|
|
from BFD and a few other BFD internal routines to locate the debugging
|
|
information. As much as possible, GDB should not depend on the BFD
|
|
internal data structures.
|
|
|
|
For some targets (e.g., COFF), there is a special transfer vector used
|
|
to call swapping routines, since the external data structures on various
|
|
platforms have different sizes and layouts. Specialized routines that
|
|
will only ever be implemented by one object file format may be called
|
|
directly. This interface should be described in a file
|
|
@file{bfd/libxxx.h}, which is included by GDB.
|
|
|
|
If you are adding a new operating system for an existing CPU chip, add a
|
|
@file{tm-@var{xos}.h} file that describes the operating system
|
|
facilities that are unusual (extra symbol table info; the breakpoint
|
|
instruction needed; etc). Then write a
|
|
@file{tm-@var{xarch}-@var{xos}.h} that just @code{#include}s
|
|
@file{tm-@var{xarch}.h} and @file{tm-@var{xos}.h}. (Now that we have
|
|
three-part configuration names, this will probably get revised to
|
|
separate the @var{xos} configuration from the @var{xarch}
|
|
configuration.)
|
|
|
|
|
|
@node Languages
|
|
@chapter Adding a Source Language to GDB
|
|
|
|
To add other languages to GDB's expression parser, follow the following steps:
|
|
|
|
@table @emph
|
|
@item Create the expression parser.
|
|
|
|
This should reside in a file @file{@var{lang}-exp.y}. Routines for building
|
|
parsed expressions into a @samp{union exp_element} list are in @file{parse.c}.
|
|
|
|
Since we can't depend upon everyone having Bison, and YACC produces
|
|
parsers that define a bunch of global names, the following lines
|
|
@emph{must} be included at the top of the YACC parser, to prevent
|
|
the various parsers from defining the same global names:
|
|
|
|
@example
|
|
#define yyparse @var{lang}_parse
|
|
#define yylex @var{lang}_lex
|
|
#define yyerror @var{lang}_error
|
|
#define yylval @var{lang}_lval
|
|
#define yychar @var{lang}_char
|
|
#define yydebug @var{lang}_debug
|
|
#define yypact @var{lang}_pact
|
|
#define yyr1 @var{lang}_r1
|
|
#define yyr2 @var{lang}_r2
|
|
#define yydef @var{lang}_def
|
|
#define yychk @var{lang}_chk
|
|
#define yypgo @var{lang}_pgo
|
|
#define yyact @var{lang}_act
|
|
#define yyexca @var{lang}_exca
|
|
#define yyerrflag @var{lang}_errflag
|
|
#define yynerrs @var{lang}_nerrs
|
|
@end example
|
|
|
|
At the bottom of your parser, define a @code{struct language_defn} and
|
|
initialize it with the right values for your language. Define an
|
|
@code{initialize_@var{lang}} routine and have it call
|
|
@samp{add_language(@var{lang}_language_defn)} to tell the rest of GDB
|
|
that your language exists. You'll need some other supporting variables
|
|
and functions, which will be used via pointers from your
|
|
@code{@var{lang}_language_defn}. See the declaration of @code{struct
|
|
language_defn} in @file{language.h}, and the other @file{*-exp.y} files,
|
|
for more information.
|
|
|
|
@item Add any evaluation routines, if necessary
|
|
|
|
If you need new opcodes (that represent the operations of the language),
|
|
add them to the enumerated type in @file{expression.h}. Add support
|
|
code for these operations in @code{eval.c:evaluate_subexp()}. Add cases
|
|
for new opcodes in two functions from @file{parse.c}:
|
|
@code{prefixify_subexp()} and @code{length_of_subexp()}. These compute
|
|
the number of @code{exp_element}s that a given operation takes up.
|
|
|
|
@item Update some existing code
|
|
|
|
Add an enumerated identifier for your language to the enumerated type
|
|
@code{enum language} in @file{defs.h}.
|
|
|
|
Update the routines in @file{language.c} so your language is included. These
|
|
routines include type predicates and such, which (in some cases) are
|
|
language dependent. If your language does not appear in the switch
|
|
statement, an error is reported.
|
|
|
|
Also included in @file{language.c} is the code that updates the variable
|
|
@code{current_language}, and the routines that translate the
|
|
@code{language_@var{lang}} enumerated identifier into a printable
|
|
string.
|
|
|
|
Update the function @code{_initialize_language} to include your language. This
|
|
function picks the default language upon startup, so is dependent upon
|
|
which languages that GDB is built for.
|
|
|
|
Update @code{allocate_symtab} in @file{symfile.c} and/or symbol-reading
|
|
code so that the language of each symtab (source file) is set properly.
|
|
This is used to determine the language to use at each stack frame level.
|
|
Currently, the language is set based upon the extension of the source
|
|
file. If the language can be better inferred from the symbol
|
|
information, please set the language of the symtab in the symbol-reading
|
|
code.
|
|
|
|
Add helper code to @code{expprint.c:print_subexp()} to handle any new
|
|
expression opcodes you have added to @file{expression.h}. Also, add the
|
|
printed representations of your operators to @code{op_print_tab}.
|
|
|
|
@item Add a place of call
|
|
|
|
Add a call to @code{@var{lang}_parse()} and @code{@var{lang}_error} in
|
|
@code{parse.c:parse_exp_1()}.
|
|
|
|
@item Use macros to trim code
|
|
|
|
The user has the option of building GDB for some or all of the
|
|
languages. If the user decides to build GDB for the language
|
|
@var{lang}, then every file dependent on @file{language.h} will have the
|
|
macro @code{_LANG_@var{lang}} defined in it. Use @code{#ifdef}s to
|
|
leave out large routines that the user won't need if he or she is not
|
|
using your language.
|
|
|
|
Note that you do not need to do this in your YACC parser, since if GDB
|
|
is not build for @var{lang}, then @file{@var{lang}-exp.tab.o} (the
|
|
compiled form of your parser) is not linked into GDB at all.
|
|
|
|
See the file @file{configure.in} for how GDB is configured for different
|
|
languages.
|
|
|
|
@item Edit @file{Makefile.in}
|
|
|
|
Add dependencies in @file{Makefile.in}. Make sure you update the macro
|
|
variables such as @code{HFILES} and @code{OBJS}, otherwise your code may
|
|
not get linked in, or, worse yet, it may not get @code{tar}red into the
|
|
distribution!
|
|
@end table
|
|
|
|
|
|
@node Releases
|
|
@chapter Configuring GDB for Release
|
|
|
|
From the top level directory (containing @file{gdb}, @file{bfd},
|
|
@file{libiberty}, and so on):
|
|
@example
|
|
make -f Makefile.in gdb.tar.Z
|
|
@end example
|
|
|
|
This will properly configure, clean, rebuild any files that are
|
|
distributed pre-built (e.g. @file{c-exp.tab.c} or @file{refcard.ps}),
|
|
and will then make a tarfile. (If the top level directory has already
|
|
beenn configured, you can just do @code{make gdb.tar.Z} instead.)
|
|
|
|
This procedure requires:
|
|
@itemize @bullet
|
|
@item symbolic links
|
|
@item @code{makeinfo} (texinfo2 level)
|
|
@item @TeX{}
|
|
@item @code{dvips}
|
|
@item @code{yacc} or @code{bison}
|
|
@end itemize
|
|
@noindent
|
|
@dots{} and the usual slew of utilities (@code{sed}, @code{tar}, etc.).
|
|
|
|
@subheading TEMPORARY RELEASE PROCEDURE FOR DOCUMENTATION
|
|
|
|
@file{gdb.texinfo} is currently marked up using the texinfo-2 macros,
|
|
which are not yet a default for anything (but we have to start using
|
|
them sometime).
|
|
|
|
For making paper, the only thing this implies is the right generation of
|
|
@file{texinfo.tex} needs to be included in the distribution.
|
|
|
|
For making info files, however, rather than duplicating the texinfo2
|
|
distribution, generate @file{gdb-all.texinfo} locally, and include the files
|
|
@file{gdb.info*} in the distribution. Note the plural; @code{makeinfo} will
|
|
split the document into one overall file and five or so included files.
|
|
|
|
|
|
@node Partial Symbol Tables
|
|
@chapter Partial Symbol Tables
|
|
|
|
GDB has three types of symbol tables.
|
|
|
|
@itemize @bullet
|
|
@item full symbol tables (symtabs). These contain the main
|
|
information about symbols and addresses.
|
|
@item partial symbol tables (psymtabs). These contain enough
|
|
information to know when to read the corresponding
|
|
part of the full symbol table.
|
|
@item minimal symbol tables (msymtabs). These contain information
|
|
gleaned from non-debugging symbols.
|
|
@end itemize
|
|
|
|
This section describes partial symbol tables.
|
|
|
|
A psymtab is constructed by doing a very quick pass over an executable
|
|
file's debugging information. Small amounts of information are
|
|
extracted -- enough to identify which parts of the symbol table will
|
|
need to be re-read and fully digested later, when the user needs the
|
|
information. The speed of this pass causes GDB to start up very
|
|
quickly. Later, as the detailed rereading occurs, it occurs in small
|
|
pieces, at various times, and the delay therefrom is mostly invisible to
|
|
the user. (@xref{Symbol Reading}.)
|
|
|
|
The symbols that show up in a file's psymtab should be, roughly, those
|
|
visible to the debugger's user when the program is not running code from
|
|
that file. These include external symbols and types, static
|
|
symbols and types, and enum values declared at file scope.
|
|
|
|
The psymtab also contains the range of instruction addresses that the
|
|
full symbol table would represent.
|
|
|
|
The idea is that there are only two ways for the user (or much of
|
|
the code in the debugger) to reference a symbol:
|
|
|
|
@itemize @bullet
|
|
|
|
@item by its address
|
|
(e.g. execution stops at some address which is inside a function
|
|
in this file). The address will be noticed to be in the
|
|
range of this psymtab, and the full symtab will be read in.
|
|
@code{find_pc_function}, @code{find_pc_line}, and other @code{find_pc_@dots{}}
|
|
functions handle this.
|
|
|
|
@item by its name
|
|
(e.g. the user asks to print a variable, or set a breakpoint on a
|
|
function). Global names and file-scope names will be found in the
|
|
psymtab, which will cause the symtab to be pulled in. Local names will
|
|
have to be qualified by a global name, or a file-scope name, in which
|
|
case we will have already read in the symtab as we evaluated the
|
|
qualifier. Or, a local symbol can be referenced when
|
|
we are "in" a local scope, in which case the first case applies.
|
|
@code{lookup_symbol} does most of the work here.
|
|
|
|
@end itemize
|
|
|
|
The only reason that psymtabs exist is to cause a symtab to be read in
|
|
at the right moment. Any symbol that can be elided from a psymtab,
|
|
while still causing that to happen, should not appear in it. Since
|
|
psymtabs don't have the idea of scope, you can't put local symbols in
|
|
them anyway. Psymtabs don't have the idea of the type of a symbol,
|
|
either, so types need not appear, unless they will be referenced by
|
|
name.
|
|
|
|
It is a bug for GDB to behave one way when only a psymtab has been read,
|
|
and another way if the corresponding symtab has been read in. Such
|
|
bugs are typically caused by a psymtab that does not contain all the
|
|
visible symbols, or which has the wrong instruction address ranges.
|
|
|
|
The psymtab for a particular section of a symbol-file (objfile)
|
|
could be thrown away after the symtab has been read in. The symtab
|
|
should always be searched before the psymtab, so the psymtab will
|
|
never be used (in a bug-free environment). Currently,
|
|
psymtabs are allocated on an obstack, and all the psymbols themselves
|
|
are allocated in a pair of large arrays on an obstack, so there is
|
|
little to be gained by trying to free them unless you want to do a lot
|
|
more work.
|
|
|
|
@node Types
|
|
@chapter Types
|
|
|
|
Fundamental Types (e.g., FT_VOID, FT_BOOLEAN).
|
|
|
|
These are the fundamental types that GDB uses internally. Fundamental
|
|
types from the various debugging formats (stabs, ELF, etc) are mapped into
|
|
one of these. They are basically a union of all fundamental types that
|
|
gdb knows about for all the languages that GDB knows about.
|
|
|
|
Type Codes (e.g., TYPE_CODE_PTR, TYPE_CODE_ARRAY).
|
|
|
|
Each time GDB builds an internal type, it marks it with one of these
|
|
types. The type may be a fundamental type, such as TYPE_CODE_INT, or
|
|
a derived type, such as TYPE_CODE_PTR which is a pointer to another
|
|
type. Typically, several FT_* types map to one TYPE_CODE_* type, and
|
|
are distinguished by other members of the type struct, such as whether
|
|
the type is signed or unsigned, and how many bits it uses.
|
|
|
|
Builtin Types (e.g., builtin_type_void, builtin_type_char).
|
|
|
|
These are instances of type structs that roughly correspond to fundamental
|
|
types and are created as global types for GDB to use for various ugly
|
|
historical reasons. We eventually want to eliminate these. Note for
|
|
example that builtin_type_int initialized in gdbtypes.c is basically the
|
|
same as a TYPE_CODE_INT type that is initialized in c-lang.c for an
|
|
FT_INTEGER fundamental type. The difference is that the builtin_type is
|
|
not associated with any particular objfile, and only one instance exists,
|
|
while c-lang.c builds as many TYPE_CODE_INT types as needed, with each
|
|
one associated with some particular objfile.
|
|
|
|
@node BFD support for GDB
|
|
@chapter Binary File Descriptor Library Support for GDB
|
|
|
|
BFD provides support for GDB in several ways:
|
|
|
|
@table @emph
|
|
@item identifying executable and core files
|
|
BFD will identify a variety of file types, including a.out, coff, and
|
|
several variants thereof, as well as several kinds of core files.
|
|
|
|
@item access to sections of files
|
|
BFD parses the file headers to determine the names, virtual addresses,
|
|
sizes, and file locations of all the various named sections in files
|
|
(such as the text section or the data section). GDB simply calls
|
|
BFD to read or write section X at byte offset Y for length Z.
|
|
|
|
@item specialized core file support
|
|
BFD provides routines to determine the failing command name stored
|
|
in a core file, the signal with which the program failed, and whether
|
|
a core file matches (i.e. could be a core dump of) a particular executable
|
|
file.
|
|
|
|
@item locating the symbol information
|
|
GDB uses an internal interface of BFD to determine where to find the
|
|
symbol information in an executable file or symbol-file. GDB itself
|
|
handles the reading of symbols, since BFD does not ``understand'' debug
|
|
symbols, but GDB uses BFD's cached information to find the symbols,
|
|
string table, etc.
|
|
@end table
|
|
|
|
@c The interface for symbol reading is described in @ref{Symbol
|
|
@c Reading,,Symbol Reading}.
|
|
|
|
|
|
@node Symbol Reading
|
|
@chapter Symbol Reading
|
|
|
|
GDB reads symbols from "symbol files". The usual symbol file is the
|
|
file containing the program which GDB is debugging. GDB can be directed
|
|
to use a different file for symbols (with the ``symbol-file''
|
|
command), and it can also read more symbols via the ``add-file'' and ``load''
|
|
commands, or while reading symbols from shared libraries.
|
|
|
|
Symbol files are initially opened by @file{symfile.c} using the BFD
|
|
library. BFD identifies the type of the file by examining its header.
|
|
@code{symfile_init} then uses this identification to locate a
|
|
set of symbol-reading functions.
|
|
|
|
Symbol reading modules identify themselves to GDB by calling
|
|
@code{add_symtab_fns} during their module initialization. The argument
|
|
to @code{add_symtab_fns} is a @code{struct sym_fns} which contains
|
|
the name (or name prefix) of the symbol format, the length of the prefix,
|
|
and pointers to four functions. These functions are called at various
|
|
times to process symbol-files whose identification matches the specified
|
|
prefix.
|
|
|
|
The functions supplied by each module are:
|
|
|
|
@table @code
|
|
@item @var{xxx}_symfile_init(struct sym_fns *sf)
|
|
|
|
Called from @code{symbol_file_add} when we are about to read a new
|
|
symbol file. This function should clean up any internal state
|
|
(possibly resulting from half-read previous files, for example)
|
|
and prepare to read a new symbol file. Note that the symbol file
|
|
which we are reading might be a new "main" symbol file, or might
|
|
be a secondary symbol file whose symbols are being added to the
|
|
existing symbol table.
|
|
|
|
The argument to @code{@var{xxx}_symfile_init} is a newly allocated
|
|
@code{struct sym_fns} whose @code{bfd} field contains the BFD
|
|
for the new symbol file being read. Its @code{private} field
|
|
has been zeroed, and can be modified as desired. Typically,
|
|
a struct of private information will be @code{malloc}'d, and
|
|
a pointer to it will be placed in the @code{private} field.
|
|
|
|
There is no result from @code{@var{xxx}_symfile_init}, but it can call
|
|
@code{error} if it detects an unavoidable problem.
|
|
|
|
@item @var{xxx}_new_init()
|
|
|
|
Called from @code{symbol_file_add} when discarding existing symbols.
|
|
This function need only handle
|
|
the symbol-reading module's internal state; the symbol table data
|
|
structures visible to the rest of GDB will be discarded by
|
|
@code{symbol_file_add}. It has no arguments and no result.
|
|
It may be called after @code{@var{xxx}_symfile_init}, if a new symbol
|
|
table is being read, or may be called alone if all symbols are
|
|
simply being discarded.
|
|
|
|
@item @var{xxx}_symfile_read(struct sym_fns *sf, CORE_ADDR addr, int mainline)
|
|
|
|
Called from @code{symbol_file_add} to actually read the symbols from a
|
|
symbol-file into a set of psymtabs or symtabs.
|
|
|
|
@code{sf} points to the struct sym_fns originally passed to
|
|
@code{@var{xxx}_sym_init} for possible initialization. @code{addr} is the
|
|
offset between the file's specified start address and its true address
|
|
in memory. @code{mainline} is 1 if this is the main symbol table being
|
|
read, and 0 if a secondary symbol file (e.g. shared library or
|
|
dynamically loaded file) is being read.@refill
|
|
@end table
|
|
|
|
In addition, if a symbol-reading module creates psymtabs when
|
|
@var{xxx}_symfile_read is called, these psymtabs will contain a pointer to
|
|
a function @code{@var{xxx}_psymtab_to_symtab}, which can be called from
|
|
any point in the GDB symbol-handling code.
|
|
|
|
@table @code
|
|
@item @var{xxx}_psymtab_to_symtab (struct partial_symtab *pst)
|
|
|
|
Called from @code{psymtab_to_symtab} (or the PSYMTAB_TO_SYMTAB
|
|
macro) if the psymtab has not already been read in and had its
|
|
@code{pst->symtab} pointer set. The argument is the psymtab
|
|
to be fleshed-out into a symtab. Upon return, pst->readin
|
|
should have been set to 1, and pst->symtab should contain a
|
|
pointer to the new corresponding symtab, or zero if there
|
|
were no symbols in that part of the symbol file.
|
|
@end table
|
|
|
|
|
|
@node Cleanups
|
|
@chapter Cleanups
|
|
|
|
Cleanups are a structured way to deal with things that need to be done
|
|
later. When your code does something (like @code{malloc} some memory, or open
|
|
a file) that needs to be undone later (e.g. free the memory or close
|
|
the file), it can make a cleanup. The cleanup will be done at some
|
|
future point: when the command is finished, when an error occurs, or
|
|
when your code decides it's time to do cleanups.
|
|
|
|
You can also discard cleanups, that is, throw them away without doing
|
|
what they say. This is only done if you ask that it be done.
|
|
|
|
Syntax:
|
|
|
|
@table @code
|
|
@item struct cleanup *@var{old_chain};
|
|
Declare a variable which will hold a cleanup chain handle.
|
|
|
|
@item @var{old_chain} = make_cleanup (@var{function}, @var{arg});
|
|
Make a cleanup which will cause @var{function} to be called with @var{arg}
|
|
(a @code{char *}) later. The result, @var{old_chain}, is a handle that can be
|
|
passed to @code{do_cleanups} or @code{discard_cleanups} later. Unless you are
|
|
going to call @code{do_cleanups} or @code{discard_cleanups} yourself,
|
|
you can ignore the result from @code{make_cleanup}.
|
|
|
|
|
|
@item do_cleanups (@var{old_chain});
|
|
Perform all cleanups done since @code{make_cleanup} returned @var{old_chain}.
|
|
E.g.:
|
|
@example
|
|
make_cleanup (a, 0);
|
|
old = make_cleanup (b, 0);
|
|
do_cleanups (old);
|
|
@end example
|
|
@noindent
|
|
will call @code{b()} but will not call @code{a()}. The cleanup that calls @code{a()} will remain
|
|
in the cleanup chain, and will be done later unless otherwise discarded.@refill
|
|
|
|
@item discard_cleanups (@var{old_chain});
|
|
Same as @code{do_cleanups} except that it just removes the cleanups from the
|
|
chain and does not call the specified functions.
|
|
|
|
@end table
|
|
|
|
Some functions, e.g. @code{fputs_filtered()} or @code{error()}, specify that they
|
|
``should not be called when cleanups are not in place''. This means
|
|
that any actions you need to reverse in the case of an error or
|
|
interruption must be on the cleanup chain before you call these functions,
|
|
since they might never return to your code (they @samp{longjmp} instead).
|
|
|
|
|
|
@node Wrapping
|
|
@chapter Wrapping Output Lines
|
|
|
|
Output that goes through @code{printf_filtered} or @code{fputs_filtered} or
|
|
@code{fputs_demangled} needs only to have calls to @code{wrap_here} added
|
|
in places that would be good breaking points. The utility routines
|
|
will take care of actually wrapping if the line width is exceeded.
|
|
|
|
The argument to @code{wrap_here} is an indentation string which is printed
|
|
@emph{only} if the line breaks there. This argument is saved away and used
|
|
later. It must remain valid until the next call to @code{wrap_here} or
|
|
until a newline has been printed through the @code{*_filtered} functions.
|
|
Don't pass in a local variable and then return!
|
|
|
|
It is usually best to call @code{wrap_here()} after printing a comma or space.
|
|
If you call it before printing a space, make sure that your indentation
|
|
properly accounts for the leading space that will print if the line wraps
|
|
there.
|
|
|
|
Any function or set of functions that produce filtered output must finish
|
|
by printing a newline, to flush the wrap buffer, before switching to
|
|
unfiltered (``@code{printf}'') output. Symbol reading routines that print
|
|
warnings are a good example.
|
|
|
|
|
|
@node Frames
|
|
@chapter Frames
|
|
|
|
A frame is a construct that GDB uses to keep track of calling and called
|
|
functions.
|
|
|
|
@table @code
|
|
@item FRAME_FP
|
|
in the machine description has no meaning to the machine-independent
|
|
part of GDB, except that it is used when setting up a new frame from
|
|
scratch, as follows:
|
|
|
|
@example
|
|
create_new_frame (read_register (FP_REGNUM), read_pc ()));
|
|
@end example
|
|
|
|
Other than that, all the meaning imparted to @code{FP_REGNUM} is imparted by
|
|
the machine-dependent code. So, @code{FP_REGNUM} can have any value that
|
|
is convenient for the code that creates new frames. (@code{create_new_frame}
|
|
calls @code{INIT_EXTRA_FRAME_INFO} if it is defined; that is where you should
|
|
use the @code{FP_REGNUM} value, if your frames are nonstandard.)
|
|
|
|
@item FRAME_CHAIN
|
|
Given a GDB frame, determine the address of the calling function's
|
|
frame. This will be used to create a new GDB frame struct, and then
|
|
@code{INIT_EXTRA_FRAME_INFO} and @code{INIT_FRAME_PC} will be called for
|
|
the new frame.
|
|
@end table
|
|
|
|
@node Remote Stubs
|
|
@chapter Remote Stubs
|
|
|
|
GDB's file @file{remote.c} talks a serial protocol to code that runs
|
|
in the target system. GDB provides several sample ``stubs'' that can
|
|
be integrated into target programs or operating systems for this purpose;
|
|
they are named @file{*-stub.c}.
|
|
|
|
The GDB user's manual describes how to put such a stub into your target
|
|
code. What follows is a discussion of integrating the SPARC stub
|
|
into a complicated operating system (rather than a simple program),
|
|
by Stu Grossman, the author of this stub.
|
|
|
|
The trap handling code in the stub assumes the following upon entry to
|
|
trap_low:
|
|
|
|
@enumerate
|
|
@item %l1 and %l2 contain pc and npc respectively at the time of the trap
|
|
@item traps are disabled
|
|
@item you are in the correct trap window
|
|
@end enumerate
|
|
|
|
As long as your trap handler can guarantee those conditions, then there is no
|
|
reason why you shouldn't be able to `share' traps with the stub. The stub has
|
|
no requirement that it be jumped to directly from the hardware trap vector.
|
|
That is why it calls @code{exceptionHandler()}, which is provided by the external
|
|
environment. For instance, this could setup the hardware traps to actually
|
|
execute code which calls the stub first, and then transfers to its own trap
|
|
handler.
|
|
|
|
For the most point, there probably won't be much of an issue with `sharing'
|
|
traps, as the traps we use are usually not used by the kernel, and often
|
|
indicate unrecoverable error conditions. Anyway, this is all controlled by a
|
|
table, and is trivial to modify.
|
|
The most important trap for us is for @code{ta 1}. Without that, we
|
|
can't single step or do breakpoints. Everything else is unnecessary
|
|
for the proper operation of the debugger/stub.
|
|
|
|
From reading the stub, it's probably not obvious how breakpoints work. They
|
|
are simply done by deposit/examine operations from GDB.
|
|
|
|
@node Longjmp Support
|
|
@chapter Longjmp Support
|
|
|
|
GDB has support for figuring out that the target is doing a
|
|
@code{longjmp} and for stopping at the target of the jump, if we are
|
|
stepping. This is done with a few specialized internal breakpoints,
|
|
which are visible in the @code{maint info breakpoint} command.
|
|
|
|
To make this work, you need to define a macro called
|
|
@code{GET_LONGJMP_TARGET}, which will examine the @code{jmp_buf}
|
|
structure and extract the longjmp target address. Since @code{jmp_buf}
|
|
is target specific, you will need to define it in the appropriate
|
|
@file{tm-xxx.h} file. Look in @file{tm-sun4os4.h} and
|
|
@file{sparc-tdep.c} for examples of how to do this.
|
|
|
|
@node Coding Style
|
|
@chapter Coding Style
|
|
|
|
GDB is generally written using the GNU coding standards, as described in
|
|
@file{standards.texi}, which is available for anonymous FTP from GNU
|
|
archive sites. There are some additional considerations for GDB
|
|
maintainers that reflect the unique environment and style of GDB
|
|
maintenance. If you follow these guidelines, GDB will be more
|
|
consistent and easier to maintain.
|
|
|
|
GDB's policy on the use of prototypes is that prototypes are used
|
|
to @emph{declare} functions but never to @emph{define} them. Simple
|
|
macros are used in the declarations, so that a non-ANSI compiler can
|
|
compile GDB without trouble. The simple macro calls are used like
|
|
this:
|
|
|
|
@example @code
|
|
extern int
|
|
memory_remove_breakpoint PARAMS ((CORE_ADDR, char *));
|
|
@end example
|
|
|
|
Note the double parentheses around the parameter types. This allows
|
|
an arbitrary number of parameters to be described, without freaking
|
|
out the C preprocessor. When the function has no parameters, it
|
|
should be described like:
|
|
|
|
@example @code
|
|
void
|
|
noprocess PARAMS ((void));
|
|
@end example
|
|
|
|
The @code{PARAMS} macro expands to its argument in ANSI C, or to a simple
|
|
@code{()} in traditional C.
|
|
|
|
All external functions should have a @code{PARAMS} declaration in a
|
|
header file that callers include. All static functions should have such
|
|
a declaration near the top of their source file.
|
|
|
|
We don't have a gcc option that will properly check that these rules
|
|
have been followed, but it's GDB policy, and we periodically check it
|
|
using the tools available (plus manual labor), and clean up any remnants.
|
|
|
|
@node Clean Design
|
|
@chapter Clean Design
|
|
|
|
In addition to getting the syntax right, there's the little question of
|
|
semantics. Some things are done in certain ways in GDB because long
|
|
experience has shown that the more obvious ways caused various kinds of
|
|
trouble. In particular:
|
|
|
|
@table @bullet
|
|
@item
|
|
You can't assume the byte order of anything that comes from a
|
|
target (including @var{value}s, object files, and instructions). Such
|
|
things must be byte-swapped using @code{SWAP_TARGET_AND_HOST} in GDB,
|
|
or one of the swap routines defined in @file{bfd.h}, such as @code{bfd_get_32}.
|
|
|
|
@item
|
|
You can't assume that you know what interface is being used to talk to
|
|
the target system. All references to the target must go through the
|
|
current @code{target_ops} vector.
|
|
|
|
@item
|
|
You can't assume that the host and target machines are the same machine
|
|
(except in the ``native'' support modules).
|
|
In particular, you can't assume that the target machine's header files
|
|
will be available on the host machine. Target code must bring along its
|
|
own header files -- written from scratch or explicitly donated by their
|
|
owner, to avoid copyright problems.
|
|
|
|
@item
|
|
Insertion of new @code{#ifdef}'s will be frowned upon. It's much better
|
|
to write the code portably than to conditionalize it for various systems.
|
|
|
|
@item
|
|
New @code{#ifdef}'s which test for specific compilers or manufacturers
|
|
or operating systems are unacceptable. All @code{#ifdef}'s should test
|
|
for features. The information about which configurations contain which
|
|
features should be segregated into the configuration files. Experience
|
|
has proven far too often that a feature unique to one particular system
|
|
often creeps into other systems; and that a conditional based on
|
|
some predefined macro for your current system will become worthless
|
|
over time, as new versions of your system come out that behave differently
|
|
with regard to this feature.
|
|
|
|
@item
|
|
Adding code that handles specific architectures, operating systems, target
|
|
interfaces, or hosts, is not acceptable in generic code. If a hook
|
|
is needed at that point, invent a generic hook and define it for your
|
|
configuration, with something like:
|
|
|
|
@example
|
|
#ifdef WRANGLE_SIGNALS
|
|
WRANGLE_SIGNALS (signo);
|
|
#endif
|
|
@end example
|
|
|
|
In your host, target, or native configuration file, as appropriate,
|
|
define @code{WRANGLE_SIGNALS} to do the machine-dependent thing. Take
|
|
a bit of care in defining the hook, so that it can be used by other
|
|
ports in the future, if they need a hook in the same place.
|
|
|
|
If the hook is not defined, the code should do whatever "most" machines
|
|
want. Using @code{#ifdef}, as above, is the preferred way to do this,
|
|
but sometimes that gets convoluted, in which case use
|
|
|
|
@example
|
|
#ifndef SPECIAL_FOO_HANDLING
|
|
#define SPECIAL_FOO_HANDLING(pc, sp) (0)
|
|
#endif
|
|
@end example
|
|
|
|
where the macro is used or in an appropriate header file.
|
|
|
|
Whether to include a @dfn{small} hook, a hook around the exact pieces of
|
|
code which are system-dependent, or whether to replace a whole function
|
|
with a hook depends on the case. A good example of this dilemma can be
|
|
found in @code{get_saved_register}. All machines that GDB 2.8 ran on
|
|
just needed the @code{FRAME_FIND_SAVED_REGS} hook to find the saved
|
|
registers. Then the SPARC and Pyramid came along, and
|
|
@code{HAVE_REGISTER_WINDOWS} and @code{REGISTER_IN_WINDOW_P} were
|
|
introduced. Then the 29k and 88k required the @code{GET_SAVED_REGISTER}
|
|
hook. The first three are examples of small hooks; the latter replaces
|
|
a whole function. In this specific case, it is useful to have both
|
|
kinds; it would be a bad idea to replace all the uses of the small hooks
|
|
with @code{GET_SAVED_REGISTER}, since that would result in much
|
|
duplicated code. Other times, duplicating a few lines of code here or
|
|
there is much cleaner than introducing a large number of small hooks.
|
|
|
|
Another way to generalize GDB along a particular interface is with an
|
|
attribute struct. For example, GDB has been generalized to handle
|
|
multiple kinds of remote interfaces -- not by #ifdef's everywhere, but
|
|
by defining the "target_ops" structure and having a current target (as
|
|
well as a stack of targets below it, for memory references). Whenever
|
|
something needs to be done that depends on which remote interface we are
|
|
using, a flag in the current target_ops structure is tested (e.g.
|
|
`target_has_stack'), or a function is called through a pointer in the
|
|
current target_ops structure. In this way, when a new remote interface
|
|
is added, only one module needs to be touched -- the one that actually
|
|
implements the new remote interface. Other examples of
|
|
attribute-structs are BFD access to multiple kinds of object file
|
|
formats, or GDB's access to multiple source languages.
|
|
|
|
Please avoid duplicating code. For example, in GDB 3.x all the code
|
|
interfacing between @code{ptrace} and the rest of GDB was duplicated in
|
|
@file{*-dep.c}, and so changing something was very painful. In GDB 4.x,
|
|
these have all been consolidated into @file{infptrace.c}.
|
|
@file{infptrace.c} can deal with variations between systems the same way
|
|
any system-independent file would (hooks, #if defined, etc.), and
|
|
machines which are radically different don't need to use infptrace.c at
|
|
all.
|
|
|
|
@item
|
|
@emph{Do} write code that doesn't depend on the sizes of C data types,
|
|
the format of the host's floating point numbers, the alignment of anything,
|
|
or the order of evaluation of expressions. In short, follow good
|
|
programming practices for writing portable C code.
|
|
|
|
@end table
|
|
|
|
@node Submitting Patches
|
|
@chapter Submitting Patches
|
|
|
|
Thanks for thinking of offering your changes back to the community of
|
|
GDB users. In general we like to get well designed enhancements.
|
|
Thanks also for checking in advance about the best way to transfer the
|
|
changes.
|
|
|
|
The two main problems with getting your patches in are,
|
|
|
|
@table @bullet
|
|
@item
|
|
The GDB maintainers will only install ``cleanly designed'' patches.
|
|
You may not always agree on what is clean design.
|
|
@pxref{Coding Style}, @pxref{Clean Design}.
|
|
|
|
@item
|
|
If the maintainers don't have time to put the patch in when it
|
|
arrives, or if there is any question about a patch, it
|
|
goes into a large queue with everyone else's patches and
|
|
bug reports.
|
|
@end table
|
|
|
|
I don't know how to get past these problems except by continuing to try.
|
|
|
|
There are two issues here -- technical and legal.
|
|
|
|
The legal issue is that to incorporate substantial changes requires a
|
|
copyright assignment from you and/or your employer, granting ownership
|
|
of the changes to the Free Software Foundation. You can get the
|
|
standard document for doing this by sending mail to
|
|
@code{gnu@@prep.ai.mit.edu} and asking for it. I recommend that people
|
|
write in "All programs owned by the Free Software Foundation" as "NAME
|
|
OF PROGRAM", so that changes in many programs (not just GDB, but GAS,
|
|
Emacs, GCC, etc) can be contributed with only one piece of legalese
|
|
pushed through the bureacracy and filed with the FSF. I can't start
|
|
merging changes until this paperwork is received by the FSF (their
|
|
rules, which I follow since I maintain it for them).
|
|
|
|
Technically, the easiest way to receive changes is to receive each
|
|
feature as a small context diff or unidiff, suitable for "patch".
|
|
Each message sent to me should include the changes to C code and
|
|
header files for a single feature, plus ChangeLog entries for each
|
|
directory where files were modified, and diffs for any changes needed
|
|
to the manuals (gdb/doc/gdb.texi or gdb/doc/gdbint.texi). If there
|
|
are a lot of changes for a single feature, they can be split down
|
|
into multiple messages.
|
|
|
|
In this way, if I read and like the feature, I can add it to the
|
|
sources with a single patch command, do some testing, and check it in.
|
|
If you leave out the ChangeLog, I have to write one. If you leave
|
|
out the doc, I have to puzzle out what needs documenting. Etc.
|
|
|
|
The reason to send each change in a separate message is that I will
|
|
not install some of the changes. They'll be returned to you with
|
|
questions or comments. If I'm doing my job, my message back to you
|
|
will say what you have to fix in order to make the change acceptable.
|
|
The reason to have separate messages for separate features is so
|
|
that other changes (which I @emph{am} willing to accept) can be installed
|
|
while one or more changes are being reworked. If multiple features
|
|
are sent in a single message, I tend to not put in the effort to sort
|
|
out the acceptable changes from the unacceptable, so none of the
|
|
features get installed until all are acceptable.
|
|
|
|
If this sounds painful or authoritarian, well, it is. But I get a lot
|
|
of bug reports and a lot of patches, and most of them don't get
|
|
installed because I don't have the time to finish the job that the bug
|
|
reporter or the contributor could have done. Patches that arrive
|
|
complete, working, and well designed, tend to get installed on the day
|
|
they arrive. The others go into a queue and get installed if and when
|
|
I scan back over the queue -- which can literally take months
|
|
sometimes. It's in both our interests to make patch installation easy
|
|
-- you get your changes installed, and I make some forward progress on
|
|
GDB in a normal 12-hour day (instead of them having to wait until I
|
|
have a 14-hour or 16-hour day to spend cleaning up patches before I
|
|
can install them).
|
|
|
|
Please send patches to @code{bug-gdb@@prep.ai.mit.edu}, if they are less
|
|
than about 25,000 characters. If longer than that, either make them
|
|
available somehow (e.g. anonymous FTP), and announce it on
|
|
@code{bug-gdb}, or send them directly to the GDB maintainers at
|
|
@code{gdb-patches@@cygnus.com}.
|
|
|
|
@node Host Conditionals
|
|
@chapter Host Conditionals
|
|
|
|
When GDB is configured and compiled, various macros are defined or left
|
|
undefined, to control compilation based on the attributes of the host
|
|
system. These macros and their meanings (or if the meaning is not
|
|
documented here, then one of the source files where they are used is
|
|
indicated) are:
|
|
|
|
@emph{NOTE: For now, both host and target conditionals are here.
|
|
Eliminate target conditionals from this list as they are identified.}
|
|
|
|
@table @code
|
|
|
|
@item BLOCK_ADDRESS_FUNCTION_RELATIVE
|
|
dbxread.c
|
|
|
|
@item GDBINIT_FILENAME
|
|
The default name of GDB's initialization file (normally @file{.gdbinit}).
|
|
|
|
@item KERNELDEBUG
|
|
tm-hppa.h
|
|
|
|
@item MEM_FNS_DECLARED
|
|
Your host config file defines this if it includes
|
|
declarations of @code{memcpy} and @code{memset}. Define this
|
|
to avoid conflicts between the native include
|
|
files and the declarations in @file{defs.h}.
|
|
|
|
@item NO_SYS_FILE
|
|
dbxread.c
|
|
@item PYRAMID_CONTROL_FRAME_DEBUGGING
|
|
pyr-xdep.c
|
|
@item SIGWINCH_HANDLER_BODY
|
|
utils.c
|
|
@item ADDITIONAL_OPTIONS
|
|
main.c
|
|
@item ADDITIONAL_OPTION_CASES
|
|
main.c
|
|
@item ADDITIONAL_OPTION_HANDLER
|
|
main.c
|
|
@item ADDITIONAL_OPTION_HELP
|
|
main.c
|
|
@item ADDR_BITS_REMOVE
|
|
defs.h
|
|
@item AIX_BUGGY_PTRACE_CONTINUE
|
|
infptrace.c
|
|
@item ALIGN_STACK_ON_STARTUP
|
|
main.c
|
|
@item ALTOS
|
|
altos-xdep.c
|
|
@item ALTOS_AS
|
|
xm-altos.h
|
|
@item ASCII_COFF
|
|
remote-adapt.c
|
|
@item BCS
|
|
tm-delta88.h
|
|
@item BEFORE_MAIN_LOOP_HOOK
|
|
main.c
|
|
@item BELIEVE_PCC_PROMOTION
|
|
coffread.c
|
|
@item BELIEVE_PCC_PROMOTION_TYPE
|
|
stabsread.c
|
|
@item BITS_BIG_ENDIAN
|
|
defs.h
|
|
@item BKPT_AT_MAIN
|
|
solib.c
|
|
@item BLOCK_ADDRESS_ABSOLUTE
|
|
dbxread.c
|
|
@item BPT_VECTOR
|
|
tm-m68k.h
|
|
|
|
@item BROKEN_LARGE_ALLOCA
|
|
Avoid large @code{alloca}'s. For example, on sun's, Large alloca's fail
|
|
because the attempt to increase the stack limit in main() fails because
|
|
shared libraries are allocated just below the initial stack limit. The
|
|
SunOS kernel will not allow the stack to grow into the area occupied by
|
|
the shared libraries.
|
|
|
|
@item CALL_DUMMY
|
|
valops.c
|
|
@item CALL_DUMMY_LOCATION
|
|
inferior.h
|
|
@item CALL_DUMMY_STACK_ADJUST
|
|
valops.c
|
|
@item CFRONT_PRODUCER
|
|
dwarfread.c
|
|
@item CHILD_PREPARE_TO_STORE
|
|
inftarg.c
|
|
@item CLEAR_DEFERRED_STORES
|
|
inflow.c
|
|
@item CLEAR_SOLIB
|
|
objfiles.c
|
|
@item COFF_ENCAPSULATE
|
|
hppabsd-tdep.c
|
|
@item COFF_FORMAT
|
|
symm-tdep.c
|
|
@item CORE_NEEDS_RELOCATION
|
|
stack.c
|
|
@item CPLUS_MARKER
|
|
cplus-dem.c
|
|
@item C_ALLOCA
|
|
regex.c
|
|
@item C_GLBLREG
|
|
coffread.c
|
|
@item DBXREAD_ONLY
|
|
partial-stab.h
|
|
@item DBX_PARM_SYMBOL_CLASS
|
|
stabsread.c
|
|
@item DEBUG_INFO
|
|
partial-stab.h
|
|
@item DEBUG_PTRACE
|
|
hppabsd-xdep.c
|
|
@item DECR_PC_AFTER_BREAK
|
|
breakpoint.c
|
|
|
|
@item DEFAULT_PROMPT
|
|
The default value of the prompt string (normally @code{"(gdb) "}).
|
|
|
|
@item DELTA88
|
|
m88k-xdep.c
|
|
@item DEV_TTY
|
|
symmisc.c
|
|
@item DGUX
|
|
m88k-xdep.c
|
|
@item DISABLE_UNSETTABLE_BREAK
|
|
breakpoint.c
|
|
@item DONT_USE_REMOTE
|
|
remote.c
|
|
@item DO_DEFERRED_STORES
|
|
infrun.c
|
|
@item DO_REGISTERS_INFO
|
|
infcmd.c
|
|
@item EXTRACT_RETURN_VALUE
|
|
tm-m68k.h
|
|
@item EXTRACT_STRUCT_VALUE_ADDRESS
|
|
values.c
|
|
@item EXTRA_FRAME_INFO
|
|
frame.h
|
|
@item EXTRA_SYMTAB_INFO
|
|
symtab.h
|
|
@item FILES_INFO_HOOK
|
|
target.c
|
|
@item FLOAT_INFO
|
|
infcmd.c
|
|
@item FOPEN_RB
|
|
defs.h
|
|
@item FUNCTION_EPILOGUE_SIZE
|
|
coffread.c
|
|
@item F_OK
|
|
xm-ultra3.h
|
|
@item GCC2_COMPILED_FLAG_SYMBOL
|
|
dbxread.c
|
|
@item GCC_COMPILED_FLAG_SYMBOL
|
|
dbxread.c
|
|
@item GCC_MANGLE_BUG
|
|
symtab.c
|
|
@item GCC_PRODUCER
|
|
dwarfread.c
|
|
@item GET_SAVED_REGISTER
|
|
findvar.c
|
|
@item GPLUS_PRODUCER
|
|
dwarfread.c
|
|
@item HANDLE_RBRAC
|
|
partial-stab.h
|
|
|
|
@item HAVE_MMAP
|
|
In some cases, use the system call @code{mmap} for reading symbol
|
|
tables. For some machines this allows for sharing and quick updates.
|
|
|
|
@item HAVE_REGISTER_WINDOWS
|
|
findvar.c
|
|
@item HAVE_SIGSETMASK
|
|
main.c
|
|
@item HAVE_TERMIO
|
|
inflow.c
|
|
@item HEADER_SEEK_FD
|
|
arm-tdep.c
|
|
@item HOSTING_ONLY
|
|
xm-rtbsd.h
|
|
@item HOST_BYTE_ORDER
|
|
findvar.c
|
|
@item HPUX_ASM
|
|
xm-hp300hpux.h
|
|
@item HPUX_VERSION_5
|
|
hp300ux-xdep.c
|
|
@item HP_OS_BUG
|
|
infrun.c
|
|
@item I80960
|
|
remote-vx.c
|
|
@item IEEE_FLOAT
|
|
valprint.c
|
|
@item IGNORE_SYMBOL
|
|
dbxread.c
|
|
@item INIT_EXTRA_FRAME_INFO
|
|
blockframe.c
|
|
@item INIT_EXTRA_SYMTAB_INFO
|
|
symfile.c
|
|
@item INIT_FRAME_PC
|
|
blockframe.c
|
|
@item INNER_THAN
|
|
valops.c
|
|
@item INT_MAX
|
|
defs.h
|
|
@item INT_MIN
|
|
defs.h
|
|
@item IN_GDB
|
|
i960-pinsn.c
|
|
@item IN_SIGTRAMP
|
|
infrun.c
|
|
@item IN_SOLIB_TRAMPOLINE
|
|
infrun.c
|
|
@item ISATTY
|
|
main.c
|
|
@item IS_TRAPPED_INTERNALVAR
|
|
values.c
|
|
@item KERNELDEBUG
|
|
dbxread.c
|
|
@item KERNEL_DEBUGGING
|
|
tm-ultra3.h
|
|
|
|
@item KERNEL_U_ADDR
|
|
Define this to the address of the @code{u} structure (the ``user struct'',
|
|
also known as the ``u-page'') in kernel virtual memory. GDB needs to know
|
|
this so that it can subtract this address from absolute addresses in
|
|
the upage, that are obtained via ptrace or from core files. On systems
|
|
that don't need this value, set it to zero.
|
|
|
|
@item KERNEL_U_ADDR_BSD
|
|
Define this to cause GDB to determine the address of @code{u} at runtime,
|
|
by using Berkeley-style @code{nlist} on the kernel's image in the root
|
|
directory.
|
|
|
|
@item KERNEL_U_ADDR_HPUX
|
|
Define this to cause GDB to determine the address of @code{u} at runtime,
|
|
by using HP-style @code{nlist} on the kernel's image in the root
|
|
directory.
|
|
|
|
@item LCC_PRODUCER
|
|
dwarfread.c
|
|
@item LOG_FILE
|
|
remote-adapt.c
|
|
@item LONGERNAMES
|
|
cplus-dem.c
|
|
@item LONGEST
|
|
defs.h
|
|
@item CC_HAS_LONG_LONG
|
|
defs.h
|
|
@item PRINTF_HAS_LONG_LONG
|
|
defs.h
|
|
@item LONG_MAX
|
|
defs.h
|
|
@item LSEEK_NOT_LINEAR
|
|
source.c
|
|
@item L_LNNO32
|
|
coffread.c
|
|
|
|
@item L_SET
|
|
This macro is used as the argument to lseek (or, most commonly, bfd_seek).
|
|
FIXME, should be replaced by SEEK_SET instead, which is the POSIX equivalent.
|
|
|
|
@item MACHKERNELDEBUG
|
|
hppabsd-tdep.c
|
|
@item MAINTENANCE
|
|
dwarfread.c
|
|
|
|
@item MAINTENANCE_CMDS
|
|
If the value of this is 1, then a number of optional maintenance commands
|
|
are compiled in.
|
|
|
|
@item MALLOC_INCOMPATIBLE
|
|
Define this if the system's prototype for @code{malloc} differs from the
|
|
@sc{ANSI} definition.
|
|
|
|
@item MIPSEL
|
|
mips-tdep.c
|
|
|
|
@item MMAP_BASE_ADDRESS
|
|
When using HAVE_MMAP, the first mapping should go at this address.
|
|
|
|
@item MMAP_INCREMENT
|
|
when using HAVE_MMAP, this is the increment between mappings.
|
|
|
|
@item MONO
|
|
ser-go32.c
|
|
@item MOTOROLA
|
|
xm-altos.h
|
|
@item NBPG
|
|
altos-xdep.c
|
|
@item NEED_POSIX_SETPGID
|
|
infrun.c
|
|
@item NEED_TEXT_START_END
|
|
exec.c
|
|
@item NFAILURES
|
|
regex.c
|
|
|
|
@item NORETURN
|
|
(in defs.h - is this really useful to define/undefine?)
|
|
|
|
@item NOTDEF
|
|
regex.c
|
|
@item NOTDEF
|
|
remote-adapt.c
|
|
@item NOTDEF
|
|
remote-mm.c
|
|
@item NOTICE_SIGNAL_HANDLING_CHANGE
|
|
infrun.c
|
|
@item NO_HIF_SUPPORT
|
|
remote-mm.c
|
|
@item NO_JOB_CONTROL
|
|
signals.h
|
|
|
|
@item NO_MMALLOC
|
|
GDB will use the @code{mmalloc} library for memory allocation for symbol
|
|
reading, unless this symbol is defined. Define it on systems
|
|
on which @code{mmalloc} does not
|
|
work for some reason. One example is the DECstation, where its RPC
|
|
library can't cope with our redefinition of @code{malloc} to call
|
|
@code{mmalloc}. When defining @code{NO_MMALLOC}, you will also have
|
|
to override the setting of @code{MMALLOC_LIB} to empty, in the Makefile.
|
|
Therefore, this define is usually set on the command line by overriding
|
|
@code{MMALLOC_DISABLE} in @file{config/*/*.mh}, rather than by defining
|
|
it in @file{xm-*.h}.
|
|
|
|
@item NO_MMALLOC_CHECK
|
|
Define this if you are using @code{mmalloc}, but don't want the overhead
|
|
of checking the heap with @code{mmcheck}.
|
|
|
|
@item NO_SIGINTERRUPT
|
|
remote-adapt.c
|
|
@item NO_SINGLE_STEP
|
|
infptrace.c
|
|
@item NS32K_SVC_IMMED_OPERANDS
|
|
ns32k-opcode.h
|
|
@item NUMERIC_REG_NAMES
|
|
mips-tdep.c
|
|
@item N_SETV
|
|
dbxread.c
|
|
@item N_SET_MAGIC
|
|
hppabsd-tdep.c
|
|
@item NaN
|
|
tm-umax.h
|
|
@item ONE_PROCESS_WRITETEXT
|
|
breakpoint.c
|
|
@item O_BINARY
|
|
exec.c
|
|
@item O_RDONLY
|
|
xm-ultra3.h
|
|
@item PC
|
|
convx-opcode.h
|
|
@item PCC_SOL_BROKEN
|
|
dbxread.c
|
|
@item PC_IN_CALL_DUMMY
|
|
inferior.h
|
|
@item PC_LOAD_SEGMENT
|
|
stack.c
|
|
@item PRINT_RANDOM_SIGNAL
|
|
infcmd.c
|
|
@item PRINT_REGISTER_HOOK
|
|
infcmd.c
|
|
@item PRINT_TYPELESS_INTEGER
|
|
valprint.c
|
|
@item PROCESS_LINENUMBER_HOOK
|
|
buildsym.c
|
|
@item PROLOGUE_FIRSTLINE_OVERLAP
|
|
infrun.c
|
|
@item PSIGNAL_IN_SIGNAL_H
|
|
defs.h
|
|
@item PUSH_ARGUMENTS
|
|
valops.c
|
|
@item PYRAMID_CONTROL_FRAME_DEBUGGING
|
|
pyr-xdep.c
|
|
@item PYRAMID_CORE
|
|
pyr-xdep.c
|
|
@item PYRAMID_PTRACE
|
|
pyr-xdep.c
|
|
@item REGISTER_BYTES
|
|
remote.c
|
|
@item REGISTER_NAMES
|
|
tm-a29k.h
|
|
@item REG_STACK_SEGMENT
|
|
exec.c
|
|
@item REG_STRUCT_HAS_ADDR
|
|
findvar.c
|
|
@item RE_NREGS
|
|
regex.h
|
|
@item R_FP
|
|
dwarfread.c
|
|
@item R_OK
|
|
xm-altos.h
|
|
@item SEEK_END
|
|
state.c
|
|
@item SEEK_SET
|
|
state.c
|
|
@item SEM
|
|
coffread.c
|
|
|
|
@item SET_STACK_LIMIT_HUGE
|
|
When defined, stack limits will be raised to their maximum. Use this
|
|
if your host supports @code{setrlimit} and you have trouble with
|
|
@code{stringtab} in @file{dbxread.c}.
|
|
|
|
Also used in @file{fork-child.c} to return stack limits before child
|
|
processes are forked.
|
|
|
|
@item SHELL_COMMAND_CONCAT
|
|
infrun.c
|
|
@item SHELL_FILE
|
|
infrun.c
|
|
@item SHIFT_INST_REGS
|
|
breakpoint.c
|
|
@item SIGN_EXTEND_CHAR
|
|
regex.c
|
|
@item SIGTRAP_STOP_AFTER_LOAD
|
|
infrun.c
|
|
@item SKIP_TRAMPOLINE_CODE
|
|
infrun.c
|
|
@item SOLIB_ADD
|
|
core.c
|
|
@item STACK_ALIGN
|
|
valops.c
|
|
@item START_INFERIOR_TRAPS_EXPECTED
|
|
infrun.c
|
|
@item STOP_SIGNAL
|
|
main.c
|
|
@item SUN4_COMPILER_FEATURE
|
|
infrun.c
|
|
@item SUN_FIXED_LBRAC_BUG
|
|
dbxread.c
|
|
@item SVR4_SHARED_LIBS
|
|
solib.c
|
|
@item SWITCH_ENUM_BUG
|
|
regex.c
|
|
@item SYM1
|
|
tm-ultra3.h
|
|
@item SYMBOL_RELOADING_DEFAULT
|
|
symfile.c
|
|
@item SYNTAX_TABLE
|
|
regex.c
|
|
@item Sword
|
|
regex.c
|
|
@item TIOCGETC
|
|
inflow.c
|
|
@item TIOCGLTC
|
|
inflow.c
|
|
@item TIOCGPGRP
|
|
inflow.c
|
|
@item TIOCLGET
|
|
inflow.c
|
|
@item TIOCLSET
|
|
inflow.c
|
|
@item TIOCNOTTY
|
|
inflow.c
|
|
@item T_ARG
|
|
coffread.c
|
|
@item T_VOID
|
|
coffread.c
|
|
@item UINT_MAX
|
|
defs.h
|
|
@item UPAGES
|
|
altos-xdep.c
|
|
@item USER
|
|
m88k-tdep.c
|
|
@item USE_GAS
|
|
xm-news.h
|
|
@item USE_O_NOCTTY
|
|
inflow.c
|
|
@item USE_STRUCT_CONVENTION
|
|
values.c
|
|
|
|
@item USG
|
|
Means that System V (prior to SVR4) include files are in use.
|
|
(FIXME: This symbol is abused in @file{infrun.c}, @file{regex.c},
|
|
@file{remote-nindy.c}, and @file{utils.c} for other things, at the moment.)
|
|
|
|
@item USIZE
|
|
xm-m88k.h
|
|
@item U_FPSTATE
|
|
i386-xdep.c
|
|
@item VARIABLES_INSIDE_BLOCK
|
|
dbxread.c
|
|
@item WRS_ORIG
|
|
remote-vx.c
|
|
@item __GNUC__
|
|
news-xdep.c
|
|
@item __GO32__
|
|
inflow.c
|
|
@item __HPUX_ASM__
|
|
xm-hp300hpux.h
|
|
@item __INT_VARARGS_H
|
|
printcmd.c
|
|
@item __not_on_pyr_yet
|
|
pyr-xdep.c
|
|
@item alloca
|
|
defs.h
|
|
@item const
|
|
defs.h
|
|
@item GOULD_PN
|
|
gould-pinsn.c
|
|
@item hp800
|
|
xm-hppabsd.h
|
|
@item hpux
|
|
hppabsd-core.c
|
|
@item lint
|
|
valarith.c
|
|
@item longest_to_int
|
|
defs.h
|
|
@item mc68020
|
|
m68k-stub.c
|
|
@item notdef
|
|
gould-pinsn.c
|
|
@item ns32k_opcodeT
|
|
ns32k-opcode.h
|
|
@item sgi
|
|
mips-tdep.c
|
|
@item sparc
|
|
regex.c
|
|
@item sun
|
|
m68k-tdep.c
|
|
@item sun386
|
|
tm-sun386.h
|
|
@item test
|
|
regex.c
|
|
@item ultrix
|
|
xm-mips.h
|
|
@item volatile
|
|
defs.h
|
|
@end table
|
|
|
|
@node Target Conditionals
|
|
@chapter Target Conditionals
|
|
|
|
When GDB is configured and compiled, various macros are defined or left
|
|
undefined, to control compilation based on the attributes of the target
|
|
system. These macros and their meanings are:
|
|
|
|
@emph{NOTE: For now, both host and target conditionals are here.
|
|
Eliminate host conditionals from this list as they are identified.}
|
|
|
|
@table @code
|
|
|
|
@item PUSH_DUMMY_FRAME
|
|
Used in @samp{call_function_by_hand} to create an artificial stack frame.
|
|
|
|
@item POP_FRAME
|
|
Used in @samp{call_function_by_hand} to remove an artificial stack frame.
|
|
|
|
@item BLOCK_ADDRESS_FUNCTION_RELATIVE
|
|
dbxread.c
|
|
@item KERNELDEBUG
|
|
tm-hppa.h
|
|
@item NO_SYS_FILE
|
|
dbxread.c
|
|
@item PYRAMID_CONTROL_FRAME_DEBUGGING
|
|
pyr-xdep.c
|
|
@item SIGWINCH_HANDLER_BODY
|
|
utils.c
|
|
@item ADDITIONAL_OPTIONS
|
|
main.c
|
|
@item ADDITIONAL_OPTION_CASES
|
|
main.c
|
|
@item ADDITIONAL_OPTION_HANDLER
|
|
main.c
|
|
@item ADDITIONAL_OPTION_HELP
|
|
main.c
|
|
@item ADDR_BITS_REMOVE
|
|
defs.h
|
|
@item ALIGN_STACK_ON_STARTUP
|
|
main.c
|
|
@item ALTOS
|
|
altos-xdep.c
|
|
@item ALTOS_AS
|
|
xm-altos.h
|
|
@item ASCII_COFF
|
|
remote-adapt.c
|
|
@item BCS
|
|
tm-delta88.h
|
|
@item BELIEVE_PCC_PROMOTION
|
|
coffread.c
|
|
@item BELIEVE_PCC_PROMOTION_TYPE
|
|
stabsread.c
|
|
@item BITS_BIG_ENDIAN
|
|
defs.h
|
|
@item BKPT_AT_MAIN
|
|
solib.c
|
|
@item BLOCK_ADDRESS_ABSOLUTE
|
|
dbxread.c
|
|
@item BPT_VECTOR
|
|
tm-m68k.h
|
|
@item BREAKPOINT
|
|
tm-m68k.h
|
|
@item CALL_DUMMY
|
|
valops.c
|
|
@item CALL_DUMMY_LOCATION
|
|
inferior.h
|
|
@item CALL_DUMMY_STACK_ADJUST
|
|
valops.c
|
|
|
|
@item CANNOT_FETCH_REGISTER (regno)
|
|
A C expression that should be nonzero if @var{regno} cannot be
|
|
fetched from an inferior process.
|
|
This is only relevant if @code{FETCH_INFERIOR_REGISTERS} is not
|
|
defined.
|
|
|
|
@item CANNOT_STORE_REGISTER (regno)
|
|
A C expression that should be nonzero if @var{regno} should not be
|
|
written to the target. This is often the case for program counters,
|
|
status words, and other special registers. If this is not defined,
|
|
GDB will assume that all registers may be written.
|
|
|
|
@item CFRONT_PRODUCER
|
|
dwarfread.c
|
|
@item CHILD_PREPARE_TO_STORE
|
|
inftarg.c
|
|
@item CLEAR_DEFERRED_STORES
|
|
inflow.c
|
|
@item CLEAR_SOLIB
|
|
objfiles.c
|
|
@item COFF_ENCAPSULATE
|
|
hppabsd-tdep.c
|
|
@item COFF_FORMAT
|
|
symm-tdep.c
|
|
@item CORE_NEEDS_RELOCATION
|
|
stack.c
|
|
@item CPLUS_MARKER
|
|
cplus-dem.c
|
|
@item C_GLBLREG
|
|
coffread.c
|
|
@item DBXREAD_ONLY
|
|
partial-stab.h
|
|
@item DBX_PARM_SYMBOL_CLASS
|
|
stabsread.c
|
|
@item DEBUG_INFO
|
|
partial-stab.h
|
|
@item DEBUG_PTRACE
|
|
hppabsd-xdep.c
|
|
@item DECR_PC_AFTER_BREAK
|
|
breakpoint.c
|
|
@item DELTA88
|
|
m88k-xdep.c
|
|
@item DEV_TTY
|
|
symmisc.c
|
|
@item DGUX
|
|
m88k-xdep.c
|
|
@item DISABLE_UNSETTABLE_BREAK
|
|
breakpoint.c
|
|
@item DONT_USE_REMOTE
|
|
remote.c
|
|
@item DO_DEFERRED_STORES
|
|
infrun.c
|
|
@item DO_REGISTERS_INFO
|
|
infcmd.c
|
|
|
|
@item END_OF_TEXT_DEFAULT
|
|
This is an expression that should designate the end of the text section
|
|
(? FIXME ?)
|
|
|
|
@item EXTRACT_RETURN_VALUE
|
|
tm-m68k.h
|
|
@item EXTRACT_STRUCT_VALUE_ADDRESS
|
|
values.c
|
|
@item EXTRA_FRAME_INFO
|
|
frame.h
|
|
@item EXTRA_SYMTAB_INFO
|
|
symtab.h
|
|
@item FILES_INFO_HOOK
|
|
target.c
|
|
@item FLOAT_INFO
|
|
infcmd.c
|
|
@item FOPEN_RB
|
|
defs.h
|
|
@item FP0_REGNUM
|
|
a68v-xdep.c
|
|
@item FPC_REGNUM
|
|
mach386-xdep.c
|
|
@item FP_REGNUM
|
|
parse.c
|
|
@item FRAMELESS_FUNCTION_INVOCATION
|
|
blockframe.c
|
|
@item FRAME_ARGS_ADDRESS_CORRECT
|
|
stack.c
|
|
|
|
@item FRAME_CHAIN
|
|
Given FRAME, return a pointer to the calling frame.
|
|
|
|
@item FRAME_CHAIN_COMBINE
|
|
blockframe.c
|
|
@item FRAME_CHAIN_VALID
|
|
frame.h
|
|
@item FRAME_CHAIN_VALID_ALTERNATE
|
|
frame.h
|
|
@item FRAME_FIND_SAVED_REGS
|
|
stack.c
|
|
@item FRAME_GET_BASEREG_VALUE
|
|
frame.h
|
|
|
|
@item FRAME_NUM_ARGS (val, fi)
|
|
For the frame described by fi, set val to the number of arguments
|
|
that are being passed.
|
|
|
|
@item FRAME_SPECIFICATION_DYADIC
|
|
stack.c
|
|
|
|
@item FRAME_SAVED_PC
|
|
Given FRAME, return the pc saved there. That is, the return address.
|
|
|
|
@item FUNCTION_EPILOGUE_SIZE
|
|
coffread.c
|
|
@item F_OK
|
|
xm-ultra3.h
|
|
@item GCC2_COMPILED_FLAG_SYMBOL
|
|
dbxread.c
|
|
@item GCC_COMPILED_FLAG_SYMBOL
|
|
dbxread.c
|
|
@item GCC_MANGLE_BUG
|
|
symtab.c
|
|
@item GCC_PRODUCER
|
|
dwarfread.c
|
|
|
|
@item GDB_TARGET_IS_HPPA
|
|
This determines whether horrible kludge code in dbxread.c and partial-stab.h
|
|
is used to mangle multiple-symbol-table files from HPPA's. This should all
|
|
be ripped out, and a scheme like elfread.c used.
|
|
|
|
@item GDB_TARGET_IS_MACH386
|
|
mach386-xdep.c
|
|
@item GDB_TARGET_IS_SUN3
|
|
a68v-xdep.c
|
|
@item GDB_TARGET_IS_SUN386
|
|
sun386-xdep.c
|
|
|
|
@item GET_LONGJMP_TARGET
|
|
For most machines, this is a target-dependent parameter. On the DECstation
|
|
and the Iris, this is a native-dependent parameter, since <setjmp.h> is
|
|
needed to define it.
|
|
|
|
This macro determines the target PC address that longjmp() will jump
|
|
to, assuming that we have just stopped at a longjmp breakpoint. It
|
|
takes a CORE_ADDR * as argument, and stores the target PC value through
|
|
this pointer. It examines the current state of the machine as needed.
|
|
|
|
@item GET_SAVED_REGISTER
|
|
findvar.c
|
|
@item GPLUS_PRODUCER
|
|
dwarfread.c
|
|
@item GR64_REGNUM
|
|
remote-adapt.c
|
|
@item GR64_REGNUM
|
|
remote-mm.c
|
|
@item HANDLE_RBRAC
|
|
partial-stab.h
|
|
@item HAVE_68881
|
|
m68k-tdep.c
|
|
@item HAVE_REGISTER_WINDOWS
|
|
findvar.c
|
|
@item HAVE_SIGSETMASK
|
|
main.c
|
|
@item HAVE_TERMIO
|
|
inflow.c
|
|
@item HEADER_SEEK_FD
|
|
arm-tdep.c
|
|
@item HOSTING_ONLY
|
|
xm-rtbsd.h
|
|
@item HPUX_ASM
|
|
xm-hp300hpux.h
|
|
@item HPUX_VERSION_5
|
|
hp300ux-xdep.c
|
|
@item HP_OS_BUG
|
|
infrun.c
|
|
@item I80960
|
|
remote-vx.c
|
|
|
|
@item IBM6000_TARGET
|
|
Shows that we are configured for an IBM RS/6000 target. This conditional
|
|
should be eliminated (FIXME) and replaced by feature-specific macros.
|
|
It was introduced in haste and we are repenting at leisure.
|
|
|
|
@item IEEE_FLOAT
|
|
valprint.c
|
|
@item IGNORE_SYMBOL
|
|
dbxread.c
|
|
@item INIT_EXTRA_FRAME_INFO
|
|
blockframe.c
|
|
@item INIT_EXTRA_SYMTAB_INFO
|
|
symfile.c
|
|
@item INIT_FRAME_PC
|
|
blockframe.c
|
|
@item INNER_THAN
|
|
valops.c
|
|
@item INT_MAX
|
|
defs.h
|
|
@item INT_MIN
|
|
defs.h
|
|
@item IN_GDB
|
|
i960-pinsn.c
|
|
@item IN_SIGTRAMP
|
|
infrun.c
|
|
@item IN_SOLIB_TRAMPOLINE
|
|
infrun.c
|
|
@item ISATTY
|
|
main.c
|
|
@item IS_TRAPPED_INTERNALVAR
|
|
values.c
|
|
@item KERNELDEBUG
|
|
dbxread.c
|
|
@item KERNEL_DEBUGGING
|
|
tm-ultra3.h
|
|
@item LCC_PRODUCER
|
|
dwarfread.c
|
|
@item LOG_FILE
|
|
remote-adapt.c
|
|
@item LONGERNAMES
|
|
cplus-dem.c
|
|
@item LONGEST
|
|
defs.h
|
|
@item CC_HAS_LONG_LONG
|
|
defs.h
|
|
@item PRINTF_HAS_LONG_LONG
|
|
defs.h
|
|
@item LONG_MAX
|
|
defs.h
|
|
@item L_LNNO32
|
|
coffread.c
|
|
@item MACHKERNELDEBUG
|
|
hppabsd-tdep.c
|
|
@item MAINTENANCE
|
|
dwarfread.c
|
|
@item MIPSEL
|
|
mips-tdep.c
|
|
@item MOTOROLA
|
|
xm-altos.h
|
|
@item NBPG
|
|
altos-xdep.c
|
|
@item NEED_POSIX_SETPGID
|
|
infrun.c
|
|
@item NEED_TEXT_START_END
|
|
exec.c
|
|
@item NNPC_REGNUM
|
|
infrun.c
|
|
@item NOTDEF
|
|
remote-adapt.c
|
|
@item NOTDEF
|
|
remote-mm.c
|
|
@item NOTICE_SIGNAL_HANDLING_CHANGE
|
|
infrun.c
|
|
@item NO_HIF_SUPPORT
|
|
remote-mm.c
|
|
@item NO_SIGINTERRUPT
|
|
remote-adapt.c
|
|
@item NO_SINGLE_STEP
|
|
infptrace.c
|
|
@item NPC_REGNUM
|
|
infcmd.c
|
|
@item NS32K_SVC_IMMED_OPERANDS
|
|
ns32k-opcode.h
|
|
@item NUMERIC_REG_NAMES
|
|
mips-tdep.c
|
|
@item N_SETV
|
|
dbxread.c
|
|
@item N_SET_MAGIC
|
|
hppabsd-tdep.c
|
|
@item NaN
|
|
tm-umax.h
|
|
@item ONE_PROCESS_WRITETEXT
|
|
breakpoint.c
|
|
@item PC
|
|
convx-opcode.h
|
|
@item PCC_SOL_BROKEN
|
|
dbxread.c
|
|
@item PC_IN_CALL_DUMMY
|
|
inferior.h
|
|
@item PC_LOAD_SEGMENT
|
|
stack.c
|
|
@item PC_REGNUM
|
|
parse.c
|
|
@item PRINT_RANDOM_SIGNAL
|
|
infcmd.c
|
|
@item PRINT_REGISTER_HOOK
|
|
infcmd.c
|
|
@item PRINT_TYPELESS_INTEGER
|
|
valprint.c
|
|
@item PROCESS_LINENUMBER_HOOK
|
|
buildsym.c
|
|
@item PROLOGUE_FIRSTLINE_OVERLAP
|
|
infrun.c
|
|
@item PSIGNAL_IN_SIGNAL_H
|
|
defs.h
|
|
@item PS_REGNUM
|
|
parse.c
|
|
@item PUSH_ARGUMENTS
|
|
valops.c
|
|
@item REGISTER_BYTES
|
|
remote.c
|
|
@item REGISTER_NAMES
|
|
tm-a29k.h
|
|
@item REG_STACK_SEGMENT
|
|
exec.c
|
|
@item REG_STRUCT_HAS_ADDR
|
|
findvar.c
|
|
@item R_FP
|
|
dwarfread.c
|
|
@item R_OK
|
|
xm-altos.h
|
|
|
|
@item SDB_REG_TO_REGNUM
|
|
Define this to convert sdb register numbers
|
|
into GDB regnums. If not defined, no conversion will be done.
|
|
|
|
@item SEEK_END
|
|
state.c
|
|
@item SEEK_SET
|
|
state.c
|
|
@item SEM
|
|
coffread.c
|
|
@item SHELL_COMMAND_CONCAT
|
|
infrun.c
|
|
@item SHELL_FILE
|
|
infrun.c
|
|
@item SHIFT_INST_REGS
|
|
breakpoint.c
|
|
@item SIGTRAP_STOP_AFTER_LOAD
|
|
infrun.c
|
|
|
|
@item SKIP_PROLOGUE
|
|
A C statement that advances the PC across any function entry
|
|
prologue instructions so as to reach ``real'' code.
|
|
|
|
@item SKIP_PROLOGUE_FRAMELESS_P
|
|
A C statement that should behave similarly, but that can stop
|
|
as soon as the function is known to have a frame.
|
|
If not defined, @code{SKIP_PROLOGUE} will be used instead.
|
|
|
|
@item SKIP_TRAMPOLINE_CODE
|
|
infrun.c
|
|
@item SOLIB_ADD
|
|
core.c
|
|
@item SP_REGNUM
|
|
parse.c
|
|
|
|
@item STAB_REG_TO_REGNUM
|
|
Define this to convert stab register numbers (as gotten from `r' declarations)
|
|
into GDB regnums. If not defined, no conversion will be done.
|
|
|
|
@item STACK_ALIGN
|
|
valops.c
|
|
@item START_INFERIOR_TRAPS_EXPECTED
|
|
infrun.c
|
|
@item STOP_SIGNAL
|
|
main.c
|
|
|
|
@item STORE_RETURN_VALUE (type, valbuf)
|
|
A C expression that stores a function return value of type @var{type},
|
|
where @var{valbuf} is the address of the value to be stored.
|
|
|
|
@item SUN4_COMPILER_FEATURE
|
|
infrun.c
|
|
@item SUN_FIXED_LBRAC_BUG
|
|
dbxread.c
|
|
@item SVR4_SHARED_LIBS
|
|
solib.c
|
|
@item SYM1
|
|
tm-ultra3.h
|
|
@item SYMBOL_RELOADING_DEFAULT
|
|
symfile.c
|
|
|
|
@item TARGET_BYTE_ORDER
|
|
The ordering of bytes in the target.
|
|
This must be defined to be either @code{BIG_ENDIAN} or @code{LITTLE_ENDIAN}.
|
|
|
|
@item TARGET_CHAR_BIT
|
|
Number of bits in a char; defaults to 8.
|
|
|
|
@item TARGET_COMPLEX_BIT
|
|
Number of bits in a complex number; defaults to @code{2 * TARGET_FLOAT_BIT}.
|
|
|
|
@item TARGET_DOUBLE_BIT
|
|
Number of bits in a double float; defaults to @code{8 * TARGET_CHAR_BIT}.
|
|
|
|
@item TARGET_DOUBLE_COMPLEX_BIT
|
|
Number of bits in a double complex; defaults to @code{2 * TARGET_DOUBLE_BIT}.
|
|
|
|
@item TARGET_FLOAT_BIT
|
|
Number of bits in a float; defaults to @code{4 * TARGET_CHAR_BIT}.
|
|
|
|
@item TARGET_INT_BIT
|
|
Number of bits in an integer; defaults to @code{4 * TARGET_CHAR_BIT}.
|
|
|
|
@item TARGET_LONG_BIT
|
|
Number of bits in a long integer; defaults to @code{4 * TARGET_CHAR_BIT}.
|
|
|
|
@item TARGET_LONG_DOUBLE_BIT
|
|
Number of bits in a long double float;
|
|
defaults to @code{2 * TARGET_DOUBLE_BIT}.
|
|
|
|
@item TARGET_LONG_LONG_BIT
|
|
Number of bits in a long long integer; defaults to @code{2 * TARGET_LONG_BIT}.
|
|
|
|
@item TARGET_PTR_BIT
|
|
Number of bits in a pointer; defaults to @code{TARGET_INT_BIT}.
|
|
|
|
@item TARGET_SHORT_BIT
|
|
Number of bits in a short integer; defaults to @code{2 * TARGET_CHAR_BIT}.
|
|
|
|
@item TARGET_READ_PC
|
|
@item TARGET_WRITE_PC (val, pid)
|
|
@item TARGET_READ_SP
|
|
@item TARGET_WRITE_SP
|
|
@item TARGET_READ_FP
|
|
@item TARGET_WRITE_FP
|
|
These change the behavior of @code{read_pc}, @code{write_pc},
|
|
@code{read_sp}, @code{write_sp}, @code{read_fp} and @code{write_fp}.
|
|
For most targets, these may be left undefined. GDB will call the
|
|
read and write register functions with the relevant @code{_REGNUM} argument.
|
|
|
|
These macros are useful when a target keeps one of these registers in a
|
|
hard to get at place; for example, part in a segment register and part
|
|
in an ordinary register.
|
|
|
|
@item T_ARG
|
|
coffread.c
|
|
@item T_VOID
|
|
coffread.c
|
|
@item UINT_MAX
|
|
defs.h
|
|
@item USER
|
|
m88k-tdep.c
|
|
@item USE_GAS
|
|
xm-news.h
|
|
@item USE_STRUCT_CONVENTION
|
|
values.c
|
|
@item USIZE
|
|
xm-m88k.h
|
|
@item U_FPSTATE
|
|
i386-xdep.c
|
|
@item VARIABLES_INSIDE_BLOCK
|
|
dbxread.c
|
|
@item WRS_ORIG
|
|
remote-vx.c
|
|
@item __GO32__
|
|
inflow.c
|
|
@item __HPUX_ASM__
|
|
xm-hp300hpux.h
|
|
@item __INT_VARARGS_H
|
|
printcmd.c
|
|
@item __not_on_pyr_yet
|
|
pyr-xdep.c
|
|
@item GOULD_PN
|
|
gould-pinsn.c
|
|
@item hp800
|
|
xm-hppabsd.h
|
|
@item hpux
|
|
hppabsd-core.c
|
|
@item longest_to_int
|
|
defs.h
|
|
@item mc68020
|
|
m68k-stub.c
|
|
@item ns32k_opcodeT
|
|
ns32k-opcode.h
|
|
@item sgi
|
|
mips-tdep.c
|
|
@item sun
|
|
m68k-tdep.c
|
|
@item sun386
|
|
tm-sun386.h
|
|
|
|
@item test
|
|
(Define this to enable testing code in regex.c.)
|
|
|
|
@end table
|
|
|
|
@node Native Conditionals
|
|
@chapter Native Conditionals
|
|
|
|
When GDB is configured and compiled, various macros are defined or left
|
|
undefined, to control compilation when the host and target systems
|
|
are the same. These macros should be defined (or left undefined)
|
|
in @file{nm-@var{system}.h}.
|
|
|
|
@table @code
|
|
|
|
@item ATTACH_DETACH
|
|
If defined, then GDB will include support for the @code{attach} and
|
|
@code{detach} commands.
|
|
|
|
@item FETCH_INFERIOR_REGISTERS
|
|
Define this if the native-dependent code will provide its
|
|
own routines
|
|
@code{fetch_inferior_registers} and @code{store_inferior_registers} in
|
|
@file{@var{HOST}-nat.c}.
|
|
If this symbol is @emph{not} defined, and @file{infptrace.c}
|
|
is included in this configuration, the default routines in
|
|
@file{infptrace.c} are used for these functions.
|
|
|
|
@item GET_LONGJMP_TARGET
|
|
For most machines, this is a target-dependent parameter. On the DECstation
|
|
and the Iris, this is a native-dependent parameter, since <setjmp.h> is
|
|
needed to define it.
|
|
|
|
This macro determines the target PC address that longjmp() will jump
|
|
to, assuming that we have just stopped at a longjmp breakpoint. It
|
|
takes a CORE_ADDR * as argument, and stores the target PC value through
|
|
this pointer. It examines the current state of the machine as needed.
|
|
|
|
@item PROC_NAME_FMT
|
|
Defines the format for the name of a @file{/proc} device. Should be
|
|
defined in @file{nm.h} @emph{only} in order to override the default
|
|
definition in @file{procfs.c}.
|
|
|
|
@item PTRACE_FP_BUG
|
|
mach386-xdep.c
|
|
|
|
@item PTRACE_ARG3_TYPE
|
|
The type of the third argument to the @code{ptrace} system call, if it exists
|
|
and is different from @code{int}.
|
|
|
|
@item REGISTER_U_ADDR
|
|
Defines the offset of the registers in the ``u area''; @pxref{Host}.
|
|
|
|
@item SOLIB_CREATE_INFERIOR_HOOK
|
|
Define this to expand into any shared-library-relocation code
|
|
that you want to be run just after the child process has been forked.
|
|
|
|
@item USE_PROC_FS
|
|
This determines whether small routines in @file{*-tdep.c}, which
|
|
translate register values
|
|
between GDB's internal representation and the /proc representation,
|
|
are compiled.
|
|
|
|
@item U_REGS_OFFSET
|
|
This is the offset of the registers in the upage. It need only be
|
|
defined if the generic ptrace register access routines in
|
|
@file{infptrace.c} are being used (that is,
|
|
@file{infptrace.c} is configured in, and
|
|
@code{FETCH_INFERIOR_REGISTERS} is not defined). If the default value
|
|
from @file{infptrace.c} is good enough, leave it undefined.
|
|
|
|
The default value means that u.u_ar0 @emph{points to} the location of the
|
|
registers. I'm guessing that @code{#define U_REGS_OFFSET 0} means that
|
|
u.u_ar0 @emph{is} the location of the registers.
|
|
|
|
@end table
|
|
|
|
@node Obsolete Conditionals
|
|
@chapter Obsolete Conditionals
|
|
|
|
Fragments of old code in GDB sometimes reference or set the following
|
|
configuration macros. They should not be used by new code, and
|
|
old uses should be removed as those parts of the debugger are
|
|
otherwise touched.
|
|
|
|
@table @code
|
|
@item STACK_END_ADDR
|
|
This macro used to define where the end of the stack appeared, for use
|
|
in interpreting core file formats that don't record this address in the
|
|
core file itself. This information is now configured in BFD, and GDB
|
|
gets the info portably from there. The values in GDB's configuration
|
|
files should be moved into BFD configuration files (if needed there),
|
|
and deleted from all of GDB's config files.
|
|
|
|
Any @file{@var{foo}-xdep.c} file that references STACK_END_ADDR
|
|
is so old that it has never been converted to use BFD. Now that's old!
|
|
@end table
|
|
|
|
@node XCOFF
|
|
@chapter The XCOFF Object File Format
|
|
|
|
The IBM RS/6000 running AIX uses an object file format called xcoff.
|
|
The COFF sections, symbols, and line numbers are used, but debugging
|
|
symbols are dbx-style stabs whose strings are located in the
|
|
@samp{.debug} section (rather than the string table). For more
|
|
information, @xref{Top,,,stabs,The Stabs Debugging Format}, and search
|
|
for XCOFF.
|
|
|
|
The shared library scheme has a nice clean interface for figuring out
|
|
what shared libraries are in use, but the catch is that everything which
|
|
refers to addresses (symbol tables and breakpoints at least) needs to be
|
|
relocated for both shared libraries and the main executable. At least
|
|
using the standard mechanism this can only be done once the program has
|
|
been run (or the core file has been read).
|
|
|
|
@contents
|
|
@bye
|