### C.2 Invoking the GDB `configure` Script

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 9.1 distribution is in the `gdb-9.1` directory. That directory contains:

`gdb-9.1/configure (and supporting files)`

  script for configuring GDB and all its supporting libraries

`gdb-9.1/gdb`

  the source specific to GDB itself

`gdb-9.1/bfd`

  source for the Binary File Descriptor library

`gdb-9.1/include`

  GNU include files

`gdb-9.1/libiberty`

  source for the ‘`-liberty`’ free software library

`gdb-9.1/opcodes`

  source for the library of opcode tables and disassemblers

`gdb-9.1/readline`

  source for the GNU command-line interface

There may be other subdirectories as well.

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-9.1` 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-9.1
    ./configure
    make

Running ‘`configure`’ and then running `make` builds the included supporting 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

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. The best way to do this is to pass the `--prefix` option to `configure`, and then install it with `make install`.