Stack Analyzer

A Python tool to analyze stack usage in C/C++ programs by combining compiler-generated stack usage information (.su files) with function call graphs (generated by cflow). This helps identify potential stack overflow issues in embedded systems or resource-constrained environments.

Features

• Recursively scans directories for .su files generated by GCC
• Parses call graphs from cflow output
• Calculates both direct and total stack usage for each function
• Generates a comprehensive JSON report of stack usage analysis
• Identifies the full call chain contributing to stack usage

Requirements

• Python 3.6+
• GCC with stack usage reporting capability
• GNU cflow

sudo apt install python3 gcc cflow

Usage

To see all available options:

python stack_analyzer.py --help

Generating .su Files

To generate .su files, compile your C/C++ code with GCC using the -fstack-usage flag:

For GCC

gcc -fstack-usage -c file.c

This will produce a .su file alongside each object file, containing stack usage information.

In a Makefile

Add the flag to your CFLAGS:

CFLAGS += -fstack-usage

CMake Example

add_compile_options(-fstack-usage)

Generating cflow Output

The tool expects cflow output in the GNU format with levels printed. Generate it using:

cflow --all --format=gnu --print-level <source-files> > callgraph.txt

Output Format

The tool generates a JSON file with stack info of each found function.