B. 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 20030907 distribution is in the `gdb-20030907' directory. That directory contains:

gdb-20030907/configure (and supporting files)

script for configuring GDB and all its supporting libraries

gdb-20030907/gdb

the source specific to GDB itself

gdb-20030907/bfd

source for the Binary File Descriptor library

gdb-20030907/include

GNU include files

gdb-20030907/libiberty

source for the `-liberty' free software library

gdb-20030907/opcodes

source for the library of opcode tables and disassemblers

gdb-20030907/readline

source for the GNU command-line interface

gdb-20030907/glob

source for the GNU filename pattern-matching subroutine

gdb-20030907/mmalloc

source for the GNU memory-mapped malloc package

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-20030907' directory.

First switch to the `gdb-version-number' source directory if you are not already in it; then run configure. Pass the identifier for the platform on which GDB will run as an argument.

For example:

cd gdb-20030907 ./configure host make

where host is an identifier such as `sun4' or `decstation', that identifies the platform where GDB will run. (You can often leave off host; configure tries to guess the correct value by examining your system.)

Running `configure host' and then running 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 host

If you run configure from a directory that contains source directories for multiple libraries or programs, such as the `gdb-20030907' source directory for version 20030907, configure creates configuration files for every directory level underneath (unless you tell it not to, with the `--norecursion' option).

You should run the configure script from the top directory in the source tree, the `gdb-version-number' directory. If you run configure from one of the subdirectories, you will configure only that subdirectory. That is usually not what you want. In particular, if you run the first configure from the `gdb' subdirectory of the `gdb-version-number' directory, you will omit the configuration of `bfd', `readline', and other sibling directories of the `gdb' subdirectory. This leads to build errors about missing include files such as `bfd/bfd.h'.

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.

B.1 Compiling GDB in another directory
B.2 Specifying names for hosts and targets
B.3 configure options		Summary of options for configure

B.1 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 (GNU make does), 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 is assumed.)

For example, with version 20030907, you can build GDB in a separate directory for a Sun 4 like this:

cd gdb-20030907 mkdir ../gdb-sun4 cd ../gdb-sun4 ../gdb-20030907/configure sun4 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'.

Make sure that your path to the `configure' script has just one instance of `gdb' in it. If your path to `configure' looks like `../gdb-20030907/gdb/configure', you are configuring only one subdirectory of GDB, not the whole package. This leads to build errors about missing include files such as `bfd/bfd.h'.

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-20030907' (or in a separate configured directory configured with `--srcdir=dirname/gdb-20030907'), 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.

B.2 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 as the value for target 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 i386-linux i386-pc-linux-gnu % sh config.sub alpha-linux alpha-unknown-linux-gnu % sh config.sub hp9k700 hppa1.1-hp-hpux % sh config.sub sun4 sparc-sun-sunos4.1.1 % sh config.sub sun3 m68k-sun-sunos4.1.1 % sh config.sub i986v Invalid configuration `i986v': machine `i986v' not recognized

config.sub is also distributed in the GDB source directory (`gdb-20030907', for version 20030907).

B.3 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. See Info file `configure.info', node `What Configure Does', for a full explanation of configure.

configure [--help] [--prefix=dir] [--exec-prefix=dir] [--srcdir=dirname] [--norecursion] [--rm] [--target=target] 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'.

--exec-prefix=dir

Configure the source to install programs under directory `dir'.

--srcdir=dirname

Warning: using this option requires GNU make, or another make that 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 dirname. configure creates directories under the working directory in parallel to the source directories below dirname.

--norecursion

Configure only the directory level where configure is executed; do not propagate configuration to subdirectories.

--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 ...

Configure GDB to run on the specified host.

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

There are many other options available as well, but they are generally needed for special purposes only.