https://github.com/corani/go-llvm-playground
https://github.com/corani/go-llvm-playground
Last synced: 3 months ago
JSON representation
- Host: GitHub
- URL: https://github.com/corani/go-llvm-playground
- Owner: corani
- Created: 2020-12-30T02:08:35.000Z (over 4 years ago)
- Default Branch: master
- Last Pushed: 2021-01-06T08:42:18.000Z (over 4 years ago)
- Last Synced: 2023-09-08T15:44:04.903Z (over 1 year ago)
- Language: Go
- Size: 8.79 KB
- Stars: 1
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Go LLVM Playground
Here I'm collecting some sample code I wrote while playing around with the Golang bindings for
LLVM, as they may help others get started.
## LLVM C Bindings
### Setup
I'm using Ubuntu 18.04 and Go 1.14.9 on a system that I've used for development for some time
already, so I've no idea which dependencies are required, as most of them were installed already.
1. Get the LLVM bindings:
`go get -d github.com/llvm/llvm-project/llvm/bindings/go/llvm`
Note: This pulls down the entire LLVM project, which is rather large. This will take a while!
2. Build the LLVM bindings:
```bash
cd $GOPATH/src/github.com/llvm/llvm-project/llvm/bindings/go
./build.sh -DLLVM_TARGETS_TO_BUILD=host
```
Note: This builds the entire LLVM project, so this will take a while (and use a few GB of disk)
The above will generate a `llvm_config.go` file in the `llvm` package with the CGO flags baked in.
Note: I had to install cmake from the [Kitware APT Repository](https://apt.kitware.com), as the
version in the Ubuntu repository was too old.
Note: I had to *uninstall* ninja-build, as I couldn't get this to build the project without errors
about missing libraries.
### Examples
- [src/add/main.go](src/add/main.go)
Export a simple Go function to the C namespace, generate a new module using LLVM that defines
a `main` function with two local variables. Invoke the Go function from the `main` function and
return the result.
Use the LLVM JIT compiler to execute the `main` function from within Go and print the result.
- [src/hello/main.go](src/hello/main.go)
Generate a new module using LLVM that defines a global constant for "Hello, world!" and a
`main` function that prints the string using `puts`. Write the LL, ASM and OBJ code for this
module to the current working directory, then link the object file into an executable.
I have not found a way to generate an executable directly from the LLVM bindings, so I had to
call out to `gcc` to do this.
- [src/expr/](src/expr/)
The world's worst expression parser/compiler. Read an expression (which can only exist of one
positive integer followed by a `+` or `-` followed by another positive integer, all without any
whitespace) from a file and compile a program that executes the expression and prints the result.
### Resources
- The "Add" example borrows heavily from [An introduction to LLVM in Go](https://felixangell.com/blogs/an-introduction-to-llvm-in-go).
- The "Hello" example takes some inspiration from [llvm-hello-world](https://github.com/dfellis/llvm-hello-world).
## LLIR
A library for interacting with LLVM IR in pure Go.
### Setup
`go get -u github.com/llir/llvm/...`
### Examples
- [src/hello-ir/main.go](src/hello-ir/main.go)
Generate a new module using the Go `llir/llvm` library that defines a global constant
"Hello, world!" and a `main` function that prints the string using `puts`. Write the LL for
this module to the current working directory.
To create an executable, the easiest way is to use clang:
```bash
$ go run main.go
$ clang -i hello hello.ll
```
### Resources
- [LLVM IR and Go](https://blog.gopheracademy.com/advent-2018/llvm-ir-and-go/).
- [llir/llvm documentation](https://llir.github.io/document/).