runnersaw / softsysmotivatedmimosas Goto Github PK

A lightweight, limited functionality debugger for C code.

• Deniz Celik
• Chong Swee Goh
• Sawyer Vaughan
• Chris Wallace

Our project is to create a program that replicates portions of GDB. GDB is a software program that allows developers to debug programs and give many pieces of useful information about the execution and state of the program.

See more on our project website.

cd into the gdb-lite directory and run the following make commands to compile or clean the project:

make gdb-lite # Makes a gdb-lite executable in the gdb-lite directory
make clean # Removes temporary object files for a clean rebuild

At the moment, this will only work on 64-bit versions of Linux.

• To run GDB lite, compile an executable you wish to debug. Then run ./gdb-lite MY_EXEC
• When you are in the gdb-lite console, you can use any of the following functions:

run *args here* # Runs the file with the given arguments
quit # Exits the gdb-lite executable
func # Prints the address of a given function
var # Prints the address of a global variable (If in breakpoint, prints value also)
symtable # Prints the symtable for the file
break # Allows you to enter an address to create a trap instruction at

###
# Only available in a breakpoint
###

dump # Prints the contents of the stack
resume # Will resume execution of the file

To get an address for the break command, use the print command to print the address of the function you would like to break on first.

This debugger will only work on 64 bit Linux. Modifying it to work for 32 bit Linux should be trivial, but it would be very difficult to get this debugger to work on a Mac.

To add new code to the gdb-lite project, follow the directions below. Unless otherwise stated, assume all directories are relative to the gdb-lite/ directory (i.e. when it says src/ directory, it means gdb-lite/src/).

To add new code, write a source .c file in the src/ directory. Add a header as a .h file in the include/ directory that has declarations for the functions that need to be imported into gdb-lite.c.

Next, add #include "filename.h" to gdb-lite.c.

Next, we have to add all of the new files to the Makefile. Edit the src/Makefile file. Add c_filename.o to the _OBJ variable, and h_filename.h to the _DEPS variable.