how many lines of code is the program?

is there a specification for what it is supposed to do?

did it ever work, how do you know?

Robert Schaefer .

Hello.

The code consists of three parts which I compile the using gfortran like this:

gfortran -c name1.f90

gfortran -c name2.f90

gfortran -c name3.for

After that I link them with each other using this line:

gfortran -O name1.o name2.o name3.o

After that I can create the result plot with the use of gnupolt with:

gnuplot

load 'name of plot.gpl'

I checked it before and it worked and I can see the results. but the problem is here that I want to study the code algorithm and plot the variables inside it to see what happens inside the code step by step.

The main code is nearly 1000 lines but it has some extra packages and codes which are called inside the main code.

Maybe the problem is I don't have enough information about debugging fortran codes. I checked the internet but I couldn't get a proper answer for it.

With gdb debugger I need to compile it again this time compatible with gdb.

I use this command line but it didn't work And I faced errors.

gfortran -g name1.f90

I would be thankful if you can help me to solve this issue.

hi, khalil,

I am unfamiliar with your specific tool but am familiar with debugging unfamiliar programs.

Can you try with both -c and -g?

gfortran -g -c name1.f90

The -c option is for compiling the code when there is no need to debug the code which results in some .o files. As I said above I link these .o files to make an executable file.

debugging is another story and doesn't relate to -c option.

Try it anyway and let me know if it works.

You need both, look at the options for gcc because gfortran is based on gcc.

The -c means compile but don't link, dropping the -c will cause the tool to attempt to link after compile, and generate the errors you saw with just the -g.

Robert Schaefer .

Hello.

I checked different way and finally I can find a proper way to use gdb debugger like this:

gfortran -c myprogram1.f90 -g myprogram1.f90

gfortran -c myprogram2.f90 -g myprogram2.f90

gfortran -c myprogram3.for -g myprogram3.for

gfortran -O myprogram1.o myprogram2.o myprogram3.o rstf

gdb rstf

start

Then I can use different commands to control the program debugging. I used "step" to step through the code and now I face another problem :).

I can't skip loops which I don't need to check inside and I got stuck in there and the command "step" seems not to work because I tried it too many times to finish 4500 times of loop but unfortunately it didn't get out of the loop.

Add a breakpoint at the end of the loop, then restart stepping after the breakpoint is hit.

Do you have a gdb manual?

https://www.eecs.umich.edu/courses/eecs373/readings/Debugger.pdf

Robert Schaefer

Thanks a lot. I'll try it and see if it works.