Cflow is the program that takes C files and prints out the call graph.
Some useful options:
-d to specify the depth
-r to specify where to root the graph (main is a good place to start)
-P and -A remove commonly used keywords, like strncmp et al
One way to get a reasonable graph is:
cflow -r main -d 4 $(ALL_INCLUDES) $(LTLIBRARY_SOURCES) > cflow.out cflow2dot < cflow.out > cflow.dot dot -Grankdir=LR -Tps < cflow.dot > cflow.ps
This is in Makefile and using the includes and stuff helps with getting everything we need as cflow is just using CPP and friends to do its work. It's really a compiler that doesn't produce objects as an output.
Platforms: All Unix
Location: cflow: Various, often part of OS
dot: Part of Graphviz