Introduction
I recently gave a short presentation on the topic of stacks in the GHC JavaScript backend to the GHC team at IOG. This blog post is a summary of the content.
In the context of a program produced by the GHC JavaScript backend, two different types of stack exist: The JavaScript call stack and Haskell lightweight stacks. In this post we will focus mostly on the lightweight stacks.
First we will see why using only the JavaScript call stack is not suitable for running compiled Haskell code. Then we will introduce the calling convention we use for Haskell and see how the lightweight stacks are used for making calls and passing around data. After this, we will explore in more detail how they are used for exception handling and multithreading.