GDB symbols file format

dendress · 11-09-2015, 06:22 PM

I am trying to debug a mysql event with gdb and unzipped the /usr/share/doc/mysql-server-5.5/mysqld.sym and gdb complains that it is the wrong file format.

Any thoughts?

rtmistler · 11-11-2015, 07:04 AM

GDB is looking for files which are created that contain GDB debugging information.

I can only draw a parallel, because I don't know mysql programming at all. But it appears that you can debug SQL language using GDB.

For C or C++ programming, the source files are compiled and when they are compiled, a compilation switch is used, "-ggdb" in order to generate helpful symbols for GDB debugging:

Code:

$ gcc -ggdb -o output-file source-file.c

And so when someone runs GDB against that output file, GDB will recognize the debugging symbols.

You can see if there is a compilation switch which will enable GDB debugging symbols in your resultant image file. If you are using a library or a common set of provided libraries where you are trying to debug, you'll have to either get the source of that library or find a set of it which has been compiled for debugging. The first option is usually the best, which is to recompile that library on your own and include symbols.

dendress · 11-11-2015, 10:24 AM

Quote:

Originally Posted by rtmistler

GDB is looking for files which are created that contain GDB debugging information.

I can only draw a parallel, because I don't know mysql programming at all. But it appears that you can debug SQL language using GDB.

For C or C++ programming, the source files are compiled and when they are compiled, a compilation switch is used, "-ggdb" in order to generate helpful symbols for GDB debugging:

Code:

$ gcc -ggdb-o output-file source-file.c

And so when someone runs GDB against that output file, GDB will recognize the debugging symbols.

You can see if there is a compilation switch which will enable GDB debugging symbols in your resultant image file. If you are using a library or a common set of provided libraries where you are trying to debug, you'll have to either get the source of that library or find a set of it which has been compiled for debugging. The first option is usually the best, which is to recompile that library on your own and include symbols.

I appreciate the answer. I did not pose the question correctly. I can create a trace with gdb on the mysqld process I am trying to debug, but the special symbols are not interpreted despite my using the symbol-flag and file provided with the build of mysql (/usr/share/doc/mysql-server-5.5/mysqld.sym) gdb complains that the file is in the wrong format and does not correctly interpret the mysql specific symbols, instead returning ",::??,::??,::??," etc. on the lines I really need to read.

The /usr/share/doc/mysql-server-5.5/mysqld.sym file was originally in gz format.