no debugging symbols found when using gdb

Question

GNU gdb Fedora (6.8-37.el5) Kernal 2.6.18-164.el5

I am trying to debug my application. However, everytime I pass the binary to the gdb it says:

(no debugging symbols found) 

Here is the file output of the binary, and as you can see it is not stripped:

vid: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.6.9, dynamically linked (uses shared libs), for GNU/Linux 2.6.9, not stripped 

I am compiling with the following CFLAGS:

CFLAGS = -Wall -Wextra -ggdb -O0 -Wunreachable-code 

Can anyone tell me if I am missing some simple here?

Answer 1

The most frequent cause of "no debugging symbols found" when -g is present is that there is some "stray" -s or -S argument somewhere on the link line.

From man ld:

   -s    --strip-all        Omit all symbol information from the output file.     -S    --strip-debug        Omit debugger symbol information (but not all symbols) from the output file. 

Answer 2

The application has to be both compiled and linked with -g option. I.e. you need to put -g in both CPPFLAGS and LDFLAGS.