llvm-cookbook
This cookbox contains a collection of snippets that I commonly use in my projects. I am sharing not only because I think others might find this helpful but also:
- To record these snippets somewhere so I don't have to relearn what instructions I need in order to do something that I know I had done previously somewhere, and
- Hopefully allow others to spot naieve or ignorant snippets where there are far better ways to achieve the same outcome
Each of these snippets have a set of characteristics:
- They are focused,
- They are isolated,
- They are runnable, and
- They are trivial
As far as possible there is no clutter surrounding the snippet to distract from the concept that is being illustrated.
Snippets
| Name | Description |
|---|---|
| Constant Global Variables | Initialising and referencing of constant global variables |
| Nested Scoping | A nested function accesses its surrounding scope however that function can not be passed and used outside of the surrounding scope. |
| Higher-Order Functions | A language that supports higher-order functions is a language that treats functions as values allowing these values to be manipulated. The scenarios looked at here only consider functions that have no free variables - in other words they accept arguments, return a result and, in their body, only reference global state. |
| Closures | Nested functions are able to access the state of the enclosing function. In the absence of higher-order function, this structure is static and can be stored on the stack. Add higher-order functions and it then becomes necessary to store the enclosing scope in the heap. |
Building and Running
I have created a number of scripts contained within ./bin.
| Name | Purpose |
|---|---|
build-all.sh |
Runs all of the scripts in the correct sequence to populate ./build. |
build-docs.sh |
Iterates through all of the md files in ./doc, running embedded macros and places the result into ./build. |
build-lib.sh |
This directory stores the boilerplate library code that allows the snippets to remain simple. This script runs make in ./lib. |
build-snippets.sh |
Iterates through all of the .ll snippets in ./snippets, runs llvm-as against each file, links using clang and then runs the binary placing the output into a .out file. These snippets and output results are embedded into the md content deposited into ./build when build-docs.sh is run. |
clean-all.sh |
Removes all of the temporary files except those that are contained in ./build. |