Introduction to GDB
GDB, the GNU Project debugger,
allows you to see what is going on “inside” another program
while it executes -- or what another program was doing at the
moment it crashed. Note that GDB
is most effective when tracing programs and libraries that were
built with debugging symbols and not stripped.
![[Note]](../images/note.png)
Note
Development versions of BLFS may not build or run some packages
properly if LFS or dependencies have been updated since the most
recent stable versions of the books.
Package Information
-
Download (HTTP): https://ftp.gnu.org/gnu/gdb/gdb-15.1.tar.xz
-
Download MD5 sum: 494e3beaac44e66367c3e443a4414529
-
Download size: 23 MB
-
Estimated disk space required: 806 MB (add 1.0 GB for docs;
add 720 MB for tests)
-
Estimated build time: 0.9 SBU (add 0.4 SBU for docs; see
below for tests; all using parallelism=8)
GDB Dependencies
Recommended Runtime Dependency
six-1.16.0 (Python 3 module, required at run-time
to use GDB scripts from various LFS/BLFS packages with Python 3
installed in LFS)
Optional
Doxygen-1.11.0, GCC-14.1.0 (ada, gfortran, and go
are used for tests), Guile-3.0.10, rustc-1.79.0 (used for some tests),
Valgrind-3.23.0, and SystemTap (run-time, used
for tests)
Installation of GDB
Install GDB by running the
following commands:
mkdir build &&
cd build &&
../configure --prefix=/usr \
--with-system-readline \
--with-python=/usr/bin/python3 &&
make
Optionally, to build the API documentation using Doxygen-1.11.0, run:
make -C gdb/doc doxy
Running the tests is not recommended. The results vary a lot
depending on the system architecture and what optional dependencies
are installed and what version of gcc is being used. On one system
tested, there were 140 unexpected failures (out of over 108,000
tests) and on another system there were "only" 32 unexpected
failures. The time to run the tests varies from approximately 6 SBU
to over 15 SBU when using -j8. This depends on number of tests that
time out as will as other factors.
![[Tip]](../images/tip.png)
Tip
With a plain make
check, there are many warning messages about a
missing global configuration file. These can be avoided by
running touch
global.exp and prepending the make check command with
DEJAGNU=$PWD/global.exp. In
addition the tests can be speeded up considerably by using the
make option
"-j<N>" where <N> is the number of cores on your
system.
To test the results anyway, issue:
pushd gdb/testsuite &&
make site.exp &&
echo "set gdb_test_timeout 30" >> site.exp &&
make check 2>1 | tee gdb-check.log
popd
See gdb/testsuite/README and
TestingGDB. There
are many additional problems with the test suite:
-
Clean directories are needed if re-running the tests. For
that reason, make a copy of the compiled source code
directory before the tests in case you need to run the tests
again.
-
Results depend on installed compilers.
-
On some AMD-based systems, over 200 additional tests may fail
due to a difference in the threading implementation on those
CPUs.
Now, as the root user:
make -C gdb install &&
make -C gdbserver install
If you have built the API documentation, it is now in gdb/doc/doxy.
You can install it (as the root
user):
install -d /usr/share/doc/gdb-15.1 &&
rm -rf gdb/doc/doxy/xml &&
cp -Rv gdb/doc/doxy /usr/share/doc/gdb-15.1
Command Explanations
--with-system-readline:
This switch forces GDB to use the
copy of Readline installed in LFS.
--with-python=/usr/bin/python3: This
switch forces GDB to use Python 3.