Gdb/Separate-Objdir
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C.3 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 11.0.50.20201208-git, you can build GDB in a separate directory for a Sun 4 like this:
cd gdb-11.0.50.20201208-git mkdir ../gdb-sun4 cd ../gdb-sun4 ../gdb-11.0.50.20201208-git/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
.
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-11.0.50.20201208-git/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-11.0.50.20201208-git
(or in a separate configured
directory configured with ‘--srcdir=dirname/gdb-11.0.50.20201208-git
’), 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.
Next: Config Names, Previous: Running Configure, Up: Installing GDB [Contents][Index]