cflow - Linux
Overview
cflow
is a utility that analyzes C code and generates a graphical representation of the function call graph. It can be used to visualize the structure and relationships within a C program, making it easier to understand and navigate large and complex codebases.
Syntax
cflow [options] file.c
Options/Flags
- -a: Analyze all files in the current directory.
- -D: Generate dependency information for make.
- -f
: Output the graph to the specified file. - -g: Generate a graph in the dot format for use with Graphviz.
- -I
: Include the specified path in the search for header files. - -L
: Set the recursion depth limit for function calls (default: 1). - -m: Generate a metric summary for each function.
- -M
: Specify the type of graph to generate (options:call
,calltree
,caller
). - -p: Generate a list of all functions and their calls.
- -s: Generate a summary of the graph.
- -x: Print cross-reference information.
Examples
Simple example:
cflow example.c
Generate a dot graph for Graphviz:
cflow -g example.c
Set the recursion depth limit:
cflow -L 5 example.c
Generate a metric summary:
cflow -m example.c
Common Issues
- Missing header files: If
cflow
cannot find the necessary header files, it will report errors. Ensure that all required headers are available in the search path. - Infinite recursion: If a function calls itself recursively in an endless loop,
cflow
will not terminate. Use the-L
option to limit recursion depth. - Large graphs: Analyzing large codebases can result in very large graphs. Consider using the
-s
option to generate a summary or setting the-L
option to a lower value.
Integration
cflow
can be integrated into build scripts or continuous integration pipelines to automatically generate graphs for code analysis and documentation purposes. It can also be used as a tool for debugging and understanding complex code structures.
Related Commands
dot
: Graphviz tool for visualizing graphs.gprof
: Profiling tool that provides insight into program execution.callgrind
: Call graph analyzer for profiling and debugging.