Gdb: "No Symbol Table Is Loaded"
I Keep Getting This Error Mesage When Trying to Add a Breakpoint in Gdb. I've Used These Commands to Compile: Gcc -G Main. C Utmpib2. C -O Main. O and: Cc -G...
I keep getting this error mesage when trying to add a breakpoint in gdb.
I've used these commands to compile:
gcc -g main.c utmpib2.c -o main.o
and:
cc -g main.c utmpib2.c -o main.o
and also:
g++ -g main.c utmpib2.c -o main.o
I also tried "-ggdb" instead of "-g" and I still get that error message.
I then execute gdb:
$gdb
In gdb:
(gdb)exec-file main.o
(gdb)break 59
No symbol table is loaded. Use the "file" command.
5 Answers
You have to add extra parameter -g, which generates source level debug information. It will look like:
gcc -g prog.c
After that you can use gdb in common way.
First of all, what you have is a fully compiled program, not an object file, so drop the .o extension. Now, pay attention to what the error message says, it tells you exactly how to fix your problem: "No symbol table is loaded. Use the "file" command."
(gdb) exec-file test
(gdb) b 2
No symbol table is loaded. Use the "file" command.
(gdb) file test
Reading symbols from /home/user/test/test...done.
(gdb) b 2
Breakpoint 1 at 0x80483ea: file test.c, line 2.
(gdb)
Or just pass the program on the command line.
$ gdb test
GNU gdb (GDB) 7.4
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <
[...]
Reading symbols from /home/user/test/test...done.
(gdb) b 2
Breakpoint 1 at 0x80483ea: file test.c, line 2.
(gdb)
I have the same problem and I followed this Post, it solved my problem.
Follow the following 2 steps:
- Make sure the optimization level is
-O0 - Add
-ggdbflag when compiling your program
Good luck!
I met this issue this morning because I used the same executable in DIFFERENT OSes: after compiling my program with gcc -ggdb -Wall test.c -o test in my Mac(10.15.2), I ran gdb with the executable in Ubuntu(16.04) in my VirtualBox.
Fix: recompile with the same command under Ubuntu, then you should be good.
Whenever gcc on the compilation machine and gdb on the testing machine have differing versions, you may be facing debuginfo format incompatibility.
To fix that, try downgrading the debuginfo format:
gcc -gdwarf-3 ...
gcc -gdwarf-2 ...
gcc -gstabs ...
gcc -gstabs+ ...
gcc -gcoff ...
gcc -gxcoff ...
gcc -gxcoff+ ...
Or match gdb to the gcc you're using.
Sarah Jenkins is a veteran tech journalist with over 12 years of experience covering artificial intelligence, mobile innovations, and digital ethics. Her insights have appeared in leading technology publications worldwide.
