Subversion Repositories openrisc_2011-10-31

                     README for gdb-6.8 release

                     Updated 27, March, 2008

This is GDB, the GNU source-level debugger.

A summary of new features is in the file `gdb/NEWS'.

Check the GDB home page at http://www.gnu.org/software/gdb/ for up to

date release information, mailing list links and archives, etc.

The file `gdb/PROBLEMS' contains information on problems identified

late in the release cycle.  GDB's bug tracking data base at

http://www.gnu.org/software/gdb/bugs/ contains a more complete list of

bugs.

Unpacking and Installation -- quick overview

==========================

   In this release, the GDB debugger sources, the generic GNU include

files, the BFD ("binary file description") library, the readline

library, and other libraries all have directories of their own

underneath the gdb-6.8 directory.  The idea is that a variety of GNU

tools can share a common copy of these things.  Be aware of variation

over time--for example don't try to build gdb with a copy of bfd from

a release other than the gdb release (such as a binutils release),

especially if the releases are more than a few weeks apart.

Configuration scripts and makefiles exist to cruise up and down this

directory tree and automatically build all the pieces in the right

order.

   When you unpack the gdb-6.8.tar.gz file, you'll find a directory

called `gdb-6.8', which contains:

  COPYING       config-ml.in  gettext.m4   ltconfig        sim

  COPYING.LIB   config.guess  include      ltmain.sh       src-release

  Makefile.def  config.sub    install-sh   md5.sum         symlink-tree

  Makefile.in   configure     libiberty    missing         texinfo

  Makefile.tpl  configure.in  libtool.m4   mkinstalldirs   ylwrap

  README        djunpack.bat  ltcf-c.sh    move-if-change

  bfd           etc           ltcf-cxx.sh  opcodes

  config        gdb           ltcf-gcj.sh  readline

You can build GDB right in the source directory:

      cd gdb-6.8

      ./configure

      make

      cp gdb/gdb /usr/local/bin/gdb     (or wherever you want)

However, we recommend that an empty directory be used instead.

This way you do not clutter your source tree with binary files

and will be able to create different builds with different

configuration options.

You can build GDB in any empty build directory:

      mkdir build

      cd build

      /gdb-6.8/configure

      make

      cp gdb/gdb /usr/local/bin/gdb     (or wherever you want)

(Building GDB with DJGPP tools for MS-DOS/MS-Windows is slightly

different; see the file gdb-6.8/gdb/config/djgpp/README for details.)

   This will configure and build all the libraries as well as GDB.  If

`configure' can't determine your system type, specify one as its

argument, e.g., `./configure sun4' or `./configure decstation'.

   Make sure that your 'configure' line ends in 'gdb-6.8/configure':

      /berman/migchain/source/gdb-6.8/configure      # RIGHT

      /berman/migchain/source/gdb-6.8/gdb/configure  # WRONG

   The gdb package contains several subdirectories, such as 'gdb',

'bfd', and 'readline'.  If your 'configure' line ends in

'gdb-6.8/gdb/configure', then you are configuring only the gdb

subdirectory, not the whole gdb package.  This leads to build errors

such as:

      make: *** No rule to make target `../bfd/bfd.h', needed by `gdb.o'.  Stop.

   If you get other compiler errors during this stage, see the `Reporting

Bugs' section below; there are a few known problems.

   GDB requires an ISO C (ANSI C) compiler.  If you do not have an ISO

C compiler for your system, you may be able to download and install

the GNU CC compiler.  It is available via anonymous FTP from the

directory `ftp://ftp.gnu.org/pub/gnu/gcc'.  GDB also requires an ISO

C standard library.  The GDB remote server, gdbserver, builds with some

non-ISO standard libraries - e.g. for Windows CE.

   GDB uses Expat, an XML parsing library, to implement some target-specific

features.  Expat will be linked in if it is available at build time, or

those features will be disabled.  The latest version of Expat should be

available from `http://expat.sourceforge.net'.

   GDB can be used as a cross-debugger, running on a machine of one

type while debugging a program running on a machine of another type.

See below.

More Documentation

******************

   All the documentation for GDB comes as part of the machine-readable

distribution.  The documentation is written in Texinfo format, which

is a documentation system that uses a single source file to produce

both on-line information and a printed manual.  You can use one of the

Info formatting commands to create the on-line version of the

documentation and TeX (or `texi2roff') to typeset the printed version.

   GDB includes an already formatted copy of the on-line Info version

of this manual in the `gdb/doc' subdirectory.  The main Info file is

`gdb-6.8/gdb/doc/gdb.info', and it refers to subordinate files

matching `gdb.info*' in the same directory.  If necessary, you can

print out these files, or read them with any editor; but they are

easier to read using the `info' subsystem in GNU Emacs or the

standalone `info' program, available as part of the GNU Texinfo

distribution.

   If you want to format these Info files yourself, you need one of the

Info formatting programs, such as `texinfo-format-buffer' or

`makeinfo'.

   If you have `makeinfo' installed, and are in the top level GDB

source directory (`gdb-6.8', in the case of version 6.8), you can make

the Info file by typing:

      cd gdb/doc

      make info

   If you want to typeset and print copies of this manual, you need

TeX, a program to print its DVI output files, and `texinfo.tex', the

Texinfo definitions file.  This file is included in the GDB

distribution, in the directory `gdb-6.8/texinfo'.

   TeX is a typesetting program; it does not print files directly, but

produces output files called DVI files.  To print a typeset document,

you need a program to print DVI files.  If your system has TeX

installed, chances are it has such a program.  The precise command to

use depends on your system; `lpr -d' is common; another (for PostScript

devices) is `dvips'.  The DVI print command may require a file name

without any extension or a `.dvi' extension.

   TeX also requires a macro definitions file called `texinfo.tex'.

This file tells TeX how to typeset a document written in Texinfo

format.  On its own, TeX cannot read, much less typeset a Texinfo file.

 `texinfo.tex' is distributed with GDB and is located in the

`gdb-6.8/texinfo' directory.

   If you have TeX and a DVI printer program installed, you can typeset

and print this manual.  First switch to the the `gdb' subdirectory of

the main source directory (for example, to `gdb-6.8/gdb') and then type:

      make doc/gdb.dvi

   If you prefer to have the manual in PDF format, type this from the

`gdb/doc' subdirectory of the main source directory:

      make gdb.pdf

For this to work, you will need the PDFTeX package to be installed.

Installing GDB

**************

   GDB comes with a `configure' script that automates the process of

preparing GDB for installation; you can then use `make' to build the

`gdb' program.

   The GDB distribution includes all the source code you need for GDB in

a single directory, whose name is usually composed by appending the

version number to `gdb'.

   For example, the GDB version 6.8 distribution is in the `gdb-6.8'

directory.  That directory contains:

`gdb-6.8/{COPYING,COPYING.LIB}'

     Standard GNU license files.  Please read them.

`gdb-6.8/bfd'

     source for the Binary File Descriptor library

`gdb-6.8/config*'

     script for configuring GDB, along with other support files

`gdb-6.8/gdb'

     the source specific to GDB itself

`gdb-6.8/include'

     GNU include files

`gdb-6.8/libiberty'

     source for the `-liberty' free software library

`gdb-6.8/opcodes'

     source for the library of opcode tables and disassemblers

`gdb-6.8/readline'

     source for the GNU command-line interface

     NOTE:  The readline library is compiled for use by GDB, but will

     not be installed on your system when "make install" is issued.

`gdb-6.8/sim'

     source for some simulators (ARM, D10V, SPARC, M32R, MIPS, PPC, V850, etc)

`gdb-6.8/texinfo'

     The `texinfo.tex' file, which you need in order to make a printed

     manual using TeX.

`gdb-6.8/etc'

     Coding standards, useful files for editing GDB, and other

     miscellanea.

   Note: the following instructions are for building GDB on Unix or

Unix-like systems.  Instructions for building with DJGPP for

MS-DOS/MS-Windows are in the file gdb/config/djgpp/README.

   The simplest way to configure and build GDB is to run `configure'

from the `gdb-VERSION-NUMBER' source directory, which in this example

is the `gdb-6.8' directory.

   First switch to the `gdb-VERSION-NUMBER' source directory if you are

not already in it; then run `configure'.

   For example:

      cd gdb-6.8

      ./configure

      make

   Running `configure' followed by `make' builds the `bfd',

`readline', `mmalloc', and `libiberty' libraries, then `gdb' itself.

The configured source files, and the binaries, are left in the

corresponding source directories.

   `configure' is a Bourne-shell (`/bin/sh') script; if your system

does not recognize this automatically when you run a different shell,

you may need to run `sh' on it explicitly:

      sh configure

   If you run `configure' from a directory that contains source

directories for multiple libraries or programs, such as the `gdb-6.8'

source directory for version 6.8, `configure' creates configuration

files for every directory level underneath (unless you tell it not to,

with the `--norecursion' option).

   You can run the `configure' script from any of the subordinate

directories in the GDB distribution, if you only want to configure that

subdirectory; but be sure to specify a path to it.

   For example, with version 6.8, type the following to configure only

the `bfd' subdirectory:

      cd gdb-6.8/bfd

      ../configure

   You can install `gdb' anywhere; it has no hardwired paths. However,

you should make sure that the shell on your path (named by the `SHELL'

environment variable) is publicly readable.  Remember that GDB uses the

shell to start your program--some systems refuse to let GDB debug child

processes whose programs are not readable.

Compiling GDB in another directory

==================================

   If you want to run GDB versions for several host or target machines,

you need a different `gdb' compiled for each combination of host and

target.  `configure' is designed to make this easy by allowing you to

generate each configuration in a separate subdirectory, rather than in

the source directory.  If your `make' program handles the `VPATH'

feature correctly (GNU `make' and SunOS 'make' are two that should),

running `make' in each of these directories builds the `gdb' program

specified there.

   To build `gdb' in a separate directory, run `configure' with the

`--srcdir' option to specify where to find the source. (You also need

to specify a path to find `configure' itself from your working

directory.  If the path to `configure' would be the same as the

argument to `--srcdir', you can leave out the `--srcdir' option; it

will be assumed.)

   For example, with version 6.8, you can build GDB in a separate

directory for a Sun 4 like this:

     cd gdb-6.8

     mkdir ../gdb-sun4

     cd ../gdb-sun4

     ../gdb-6.8/configure

     make

   When `configure' builds a configuration using a remote source

directory, it creates a tree for the binaries with the same structure

(and using the same names) as the tree under the source directory.  In

the example, you'd find the Sun 4 library `libiberty.a' in the

directory `gdb-sun4/libiberty', and GDB itself in `gdb-sun4/gdb'.

   One popular reason to build several GDB configurations in separate

directories is to configure GDB for cross-compiling (where GDB runs on

one machine--the host--while debugging programs that run on another

machine--the target).  You specify a cross-debugging target by giving

the `--target=TARGET' option to `configure'.

   When you run `make' to build a program or library, you must run it

in a configured directory--whatever directory you were in when you

called `configure' (or one of its subdirectories).

   The `Makefile' that `configure' generates in each source directory

also runs recursively.  If you type `make' in a source directory such

as `gdb-6.8' (or in a separate configured directory configured with

`--srcdir=PATH/gdb-6.8'), you will build all the required libraries,

and then build GDB.

   When you have multiple hosts or targets configured in separate

directories, you can run `make' on them in parallel (for example, if

they are NFS-mounted on each of the hosts); they will not interfere

with each other.

Specifying names for hosts and targets

======================================

   The specifications used for hosts and targets in the `configure'

script are based on a three-part naming scheme, but some short

predefined aliases are also supported.  The full naming scheme encodes

three pieces of information in the following pattern:

     ARCHITECTURE-VENDOR-OS

   For example, you can use the alias `sun4' as a HOST argument or in a

`--target=TARGET' option.  The equivalent full name is

`sparc-sun-sunos4'.

   The `configure' script accompanying GDB does not provide any query

facility to list all supported host and target names or aliases.

`configure' calls the Bourne shell script `config.sub' to map

abbreviations to full names; you can read the script, if you wish, or

you can use it to test your guesses on abbreviations--for example:

     % sh config.sub sun4

     sparc-sun-sunos4.1.1

     % sh config.sub sun3

     m68k-sun-sunos4.1.1

     % sh config.sub decstation

     mips-dec-ultrix4.2

     % sh config.sub hp300bsd

     m68k-hp-bsd

     % sh config.sub i386v

     i386-pc-sysv

     % sh config.sub i786v

     Invalid configuration `i786v': machine `i786v' not recognized

`config.sub' is also distributed in the GDB source directory

(`gdb-6.8', for version 6.8).

`configure' options

===================

   Here is a summary of the `configure' options and arguments that are

most often useful for building GDB.  `configure' also has several other

options not listed here.  *note : (configure.info)What Configure Does,

for a full explanation of `configure'.

     configure [--help]

               [--prefix=DIR]

               [--srcdir=PATH]

               [--norecursion] [--rm]

               [--enable-build-warnings]

               [--target=TARGET]

               [--host=HOST]

               [HOST]

You may introduce options with a single `-' rather than `--' if you

prefer; but you may abbreviate option names if you use `--'.

`--help'

     Display a quick summary of how to invoke `configure'.

`-prefix=DIR'

     Configure the source to install programs and files under directory

     `DIR'.

`--srcdir=PATH'

     *Warning: using this option requires GNU `make', or another `make'

     that compatibly implements the `VPATH' feature.*

     Use this option to make configurations in directories separate

     from the GDB source directories.  Among other things, you can use

     this to build (or maintain) several configurations simultaneously,

     in separate directories.  `configure' writes configuration

     specific files in the current directory, but arranges for them to

     use the source in the directory PATH.  `configure' will create

     directories under the working directory in parallel to the source

     directories below PATH.

`--norecursion'

     Configure only the directory level where `configure' is executed;

     do not propagate configuration to subdirectories.

`--rm'

     Remove the configuration that the other arguments specify.

`--enable-build-warnings'

     When building the GDB sources, ask the compiler to warn about any

     code which looks even vaguely suspicious.  You should only using

     this feature if you're compiling with GNU CC.  It passes the

     following flags:

        -Wimplicit

        -Wreturn-type

        -Wcomment

        -Wtrigraphs

        -Wformat

        -Wparentheses

        -Wpointer-arith

`--target=TARGET'

     Configure GDB for cross-debugging programs running on the specified

     TARGET.  Without this option, GDB is configured to debug programs

     that run on the same machine (HOST) as GDB itself.

     There is no convenient way to generate a list of all available

     targets.

`--host=HOST'

     Configure GDB to run on the specified HOST.

     There is no convenient way to generate a list of all available

     hosts.

`HOST ...'

     Same as `--host=HOST'.  If you omit this, GDB will guess; it's

     quite accurate.

`configure' accepts other options, for compatibility with configuring

other GNU tools recursively; but these are the only options that affect

GDB or its supporting libraries.

Remote debugging

=================

   The files m68k-stub.c, i386-stub.c, and sparc-stub.c are examples

of remote stubs to be used with remote.c.  They are designed to run

standalone on an m68k, i386, or SPARC cpu and communicate properly

with the remote.c stub over a serial line.

   The directory gdb/gdbserver/ contains `gdbserver', a program that

allows remote debugging for Unix applications.  gdbserver is only

supported for some native configurations, including Sun 3, Sun 4, and

Linux.

The file gdb/gdbserver/README includes further notes on gdbserver; in

particular, it explains how to build gdbserver for cross-debugging

(where gdbserver runs on the target machine, which is of a different

architecture than the host machine running GDB).

   There are a number of remote interfaces for talking to existing ROM

monitors and other hardware:

        remote-mips.c    MIPS remote debugging protocol

        remote-sds.c     PowerPC SDS monitor

        remote-sim.c     Generalized simulator protocol

Reporting Bugs in GDB

=====================

   There are several ways of reporting bugs in GDB.  The prefered

method is to use the World Wide Web:

      http://www.gnu.org/software/gdb/bugs/

As an alternative, the bug report can be submitted, via e-mail, to the

address "bug-gdb@gnu.org".

   When submitting a bug, please include the GDB version number (e.g.,

gdb-6.8), and how you configured it (e.g., "sun4" or "mach386 host,

i586-intel-synopsys target").  Since GDB now supports so many

different configurations, it is important that you be precise about

this.  If at all possible, you should include the actual banner that

GDB prints when it starts up, or failing that, the actual configure

command that you used when configuring GDB.

   For more information on how/whether to report bugs, see the

Reporting Bugs chapter of the GDB manual (gdb/doc/gdb.texinfo).

Graphical interface to GDB -- X Windows, MS Windows

==========================

   Several graphical interfaces to GDB are available.  You should

check:

        http://www.gnu.org/software/gdb/links/

for an up-to-date list.

   Emacs users will very likely enjoy the Grand Unified Debugger mode;

try typing `M-x gdb RET'.

Writing Code for GDB

=====================

   There is a lot of information about writing code for GDB in the

internals manual, distributed with GDB in gdb/doc/gdbint.texinfo.  You

can read it by hand, print it by using TeX and texinfo, or process it

into an `info' file for use with Emacs' info mode or the standalone

`info' program.

   If you are pondering writing anything but a short patch, especially

take note of the information about copyrights in the node Submitting

Patches.  It can take quite a while to get all the paperwork done, so

we encourage you to start that process as soon as you decide you are

planning to work on something, or at least well ahead of when you

think you will be ready to submit the patches.

GDB Testsuite

=============

   Included with the GDB distribution is a DejaGNU based testsuite

that can either be used to test your newly built GDB, or for

regression testing a GDB with local modifications.

   Running the testsuite requires the prior installation of DejaGNU,

which is generally available via ftp.  The directory

ftp://sources.redhat.com/pub/dejagnu/ will contain a recent snapshot.

Once DejaGNU is installed, you can run the tests in one of the

following ways:

  (1)   cd gdb-6.8

        make check-gdb

or

  (2)   cd gdb-6.8/gdb

        make check

or

  (3)   cd gdb-6.8/gdb/testsuite

        make site.exp   (builds the site specific file)

        runtest -tool gdb GDB=../gdb    (or GDB= as appropriate)

The last method gives you slightly more control in case of problems

with building one or more test executables or if you are using the

testsuite `standalone', without it being part of the GDB source tree.

See the DejaGNU documentation for further details.

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