Application to visualize program flow

drcouzelis · 2010-09-29 21:33:10

I'm looking for an easier way to "visualize" what is going on in the source code of a large project, in regards to function calls, method calls, and classes.

For example, a source directory of a project will have a bunch of files, like this:

...
anim.c
character.c
direction.c
game.c
input.c
main.c
player.c
resources.c
room.c
screen.c
...

If I didn't know anything about this project, if I wanted to try to understand how it works it would be difficult to start.

Does anyone know of an application that will read source code and display a tree-like output of the program flow? For example, maybe like this:

main() [main.c]
-> create_game() [game.c]
-> reset_timer() [timer.c]
-> update_game() [game.c]
---> update_world() [world.c]
---> is_game_over() [game.c]
---> ...
-> draw_game() [game.c]
---> draw_world() [world.c
---> ...
-> destroy_game() [game.c]
...

How about for classes and method calls?

I don't care if it's GUI or CLI, or what programming language it's for. I think a program like this would be incredibly useful, especially in the FOSS community, and would be surprised if something doesn't already exist.

codycarey · 2010-09-29 21:59:13

If you just want to generate source code graphs look into Doxygen [extra/doxygen], but if you want to see the flow as it's running you'll need a debugger like gdb.

EDIT: http://www.stack.nl/~dimitri/doxygen/

Last edited by codycarey (2010-09-29 22:00:26)

drcouzelis · 2010-09-29 23:01:54

Thank you, I remember hearing about Doxygen but had forgotten about it. I installed it and am reading about how to use it. You wouldn't happen to know how to make it do what I was asking, would you?

I am interested in source code parsing, not parsing a running application.

joven · 2010-10-01 10:33:51

I've never found an app that automatically does this. When I want to do what you are describing, I use a UML tool to basically take notes as I read the code. This piece calls that piece. This class subclasses that class. It doesnt take long for the bigger picture to start emerging. Using UML to do this helps a lot because I dont need to remember anything as I go.

joven · 2010-10-01 10:34:42

I should also note that in my experience doxygen is great at displaying structure not runtime behavior.

Google · 2010-10-01 13:39:58

ptrace?

http://en.wikipedia.org/wiki/Ptrace

drcouzelis · 2010-10-02 21:15:40

Google wrote:

ptrace?

I want to learn what happens in the source code, not at run time. I don't think ptrace (or strace) can do that. Even if it did, I'd only be able to learn about how a function is called after finding a way to get the running application to call it.

joven wrote:

I've never found an app that automatically does this. When I want to do what you are describing, I use a UML tool to basically take notes as I read the code. This piece calls that piece. This class subclasses that class. It doesnt take long for the bigger picture to start emerging. Using UML to do this helps a lot because I dont need to remember anything as I go.

You described my situation very well. I, too, try to make notes like that when reading the source code of a project.

I'm very surprised there isn't a program that does this automatically. I may have found an idea for my next personal project.

SanskritFritz · 2010-10-02 21:21:24

[offtopic] joven Which UML program are you using?

drcouzelis · 2010-10-02 21:25:50

SanskritFritz wrote:

[offtopic] joven Which UML program are you using?

I don't even know what exists besides Dia.

Last edited by drcouzelis (2010-10-02 21:26:24)

ewaller · 2010-10-02 21:27:45

I guess this would not so tough with explicit function calls, but what about cases where functions are passed by reference and those references are stored for later use. Here I think of things such as call back functions or references to pseudo-objects in toolkits like Gtk.

I realize your example is for C. This gets uglier with C++ where the function that actually gets called is determined at run time as a function of inheritance.

It gets really ugly in languages that use the reflective paradigm where they can actually change their structure at runtime (Python Lua, Lisp, Ruby, etc...)

drcouzelis · 2010-10-02 21:39:58

ewaller wrote:

I guess this would not so tough with explicit function calls, but what about cases where functions are passed by reference and those references are stored for later use. Here I think of things such as call back functions or references to pseudo-objects in toolkits like Gtk.

The easiest thing to do would be to report that a function named "function_ptr_var" (or whatever the variable is called) was called. This makes sense to me.

ewaller wrote:

I realize your example is for C. This gets uglier with C++ where the function that actually gets called is determined at run time as a function of inheritance.

I would report the name of the method and the class type of the variable that called it.

ewaller wrote:

It gets really ugly in languages that use the reflective paradigm where they can actually change their structure at runtime (Python Lua, Lisp, Ruby, etc...)

I don't know enough about these languages. Maybe someone else has an idea.

codycarey · 2010-10-03 01:54:48

Well, another option is to use IDA Pro. They offer a free version for Windows, but there isn't a native Linux equivalent of it I believe. However, their standard and advanced versions which cost money do have native Linux versions. Of course, that means shelling out like $500-$1000 depending on what you get.

Do some googling to find out how well the free version works in Wine/VMs. Personally I own a standard copy of IDA Pro, it's just worth it. If you ever plan to rip apart software it has no competition.

drcouzelis · 2010-10-03 14:14:49

It looks like IDA Pro is used to watch the flow of a running application, which isn't what I'm looking for. Can it parse a directory of source code and report the flow of function calls?

tousborne · 2010-10-07 05:14:35

It's probably not everything you're hoping for, but GNU cflow might be of some use. It's also in the AUR.

http://www.gnu.org/software/cflow/
http://aur.archlinux.org/packages.php?ID=1085

drcouzelis · 2010-10-07 05:59:34

tousborne wrote:

It's probably not everything you're hoping for, but GNU cflow might be of some use.

Thank you, yes, that is exactly what I was looking for! I had never heard of cflow before.

I did an Internet search. Apparently cflow is a "call graph generator". This page lists others, including KCachegrind, codeviz, egypt, gprof, and pycallgraph. I will start trying them out.

https://secure.wikimedia.org/wikipedia/ … generators

This pretty much answers my question. After I try some out, if I find one I really like I might mention it here in this thread.

Thanks everyone!

drcouzelis · 2010-10-07 13:10:42

cflow - For C programs. Nice and simple.

KCacheGrind - Uses the "callgrind" application. I couldn't find callgrind in the Arch repositories or the AUR, so I gave up.

codeviz - For C and C++ programs. I got it to produce a beautiful PNG tree of all of my function calls. I probably won't use it. A graphical tree output isn't so useful to me, and it was a bit tricky to actually setup and use. (for example, it requires a patched version of GCC)

egypt - For C programs. Super duper simple concept, but requires some setup to use. I couldn't figure out how to configure and run it.

gprof - Part of the GNU Binary Utilities. A little too low level for what I was looking for.

pycallgraph - For Python programs. I didn't try it.

doxygen - Is able to create documentation for anything in the world, including your car. I wish someone could tell me, "Type this doxygen command to create a call graph", but until that happens, I just can't seem to figure it out.

cflow is definitely my favorite. I will do some post processing to the output to remove any functions that I didn't write.

EDIT: Someone did a similar "review" to mine here, along with mentioning more programs to try out: http://grok2.tripod.com/code_comprehension.html

Last edited by drcouzelis (2010-10-07 13:13:45)

falconindy · 2010-10-07 13:50:58

drcouzelis wrote:

I couldn't find callgrind in the Arch repositories or the AUR, so I gave up.

Because it's not an independent program.

valgrind --tool=callgrind ...

duquesnc · 2010-10-07 23:53:05

AFAIK, doxygen has a wizard easy to use. They you just run doxygen...

joven · 2010-10-25 12:50:51

SanskritFritz wrote:

[offtopic] joven Which UML program are you using?

Sorry for the delay in answer. I use a commercial tool called MagicDraw. Its awesome. I've used it for 6 or 7 years and highly recommend it. I'm a heavy UML user and have never seen another tool I would replace it with. The personal edition, which is all I have ever needed, is $149 so its not going to break the bank either. Well worth the money.

Arch Linux

#1 2010-09-29 21:33:10

Application to visualize program flow

#2 2010-09-29 21:59:13

Re: Application to visualize program flow

#3 2010-09-29 23:01:54

Re: Application to visualize program flow

#4 2010-10-01 10:33:51

Re: Application to visualize program flow

#5 2010-10-01 10:34:42

Re: Application to visualize program flow

#6 2010-10-01 13:39:58

Re: Application to visualize program flow

#7 2010-10-02 21:15:40

Re: Application to visualize program flow

#8 2010-10-02 21:21:24

Re: Application to visualize program flow

#9 2010-10-02 21:25:50

Re: Application to visualize program flow

#10 2010-10-02 21:27:45

Re: Application to visualize program flow

#11 2010-10-02 21:39:58

Re: Application to visualize program flow

#12 2010-10-03 01:54:48

Re: Application to visualize program flow

#13 2010-10-03 14:14:49

Re: Application to visualize program flow

#14 2010-10-07 05:14:35

Re: Application to visualize program flow

#15 2010-10-07 05:59:34

Re: Application to visualize program flow

#16 2010-10-07 13:10:42

Re: Application to visualize program flow

#17 2010-10-07 13:50:58

Re: Application to visualize program flow

#18 2010-10-07 23:53:05

Re: Application to visualize program flow

#19 2010-10-25 12:50:51

Re: Application to visualize program flow

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