swift-memory-debug.md

It often be helpful to be able to debug memory usage in Swift on Linux, for example to debug memory leaks.

This is a quick overview of how to generate a report of memory usage for your Swift app. This guide will only show you how to generate the report, not how to analyze it, it might be written up in a blog post later.

Install Valgrind

First we need to install a tool called Valgrind, which is used to trace memory usage.

sudo apt-get install valgrind

Run your executable

You need to build your swift app in debug mode first:

swift build

Now we need to run our Swift executable through Valgrind.

/usr/bin/valgrind --tool=massif <Path-to-executable>

e.g.:

/usr/bin/valgrind --tool=massif .build/debug/Run

Generate report

This will generate a file that looks like massif.out.<number>, run this through ms_print

ms_print massif.out.<number> | swift-demangle > report.txt

Now you can check the content of report.txt which have the full report