forge

A basic toolchain to forge (cross-compile) your multi-platform nim binaries.

Why?

Nim is a great language and the code is as portable as any other code written in C. But who wants to manage C toolchains or CI/CD DSL's to cross-compile your code into easily shareable native executable binaries

Installation

In order to use forge you must first install zig as all compilation is done using a thin wrapper around zig cc.

NOTE Future versions may use an automated/isolated zig installation.

nimble install forge

Usage

forge has a number of subcommands to facilitate compiling nim binaries (see forge --help for more info.)

forge +cc

To compile a single binary for a platform you can use forge +cc.

Example:

forge +cc --target x86_64-linux-musl -- -d:release src/forge.nim -o:forge

forge +release

This command is useful for generating many compiled binaries like you may be accustomed to seeing from go or rust cli's. forge +release will make attempts to infer many values based on the assumption that it's likely run from the root directory of a nim project with a <project>.nimble

You can either specify all commands on the CLI or use a config file.

forge +release w/configuration

Example:

forge +release --target,=x86_64-linux-musl,x86_64-macos-none --bin src/forge.nim

Result:

dist
├── forge-v2023.1001-x86_64-linux-musl
│   └── forge
└── forge-v2023.1001-x86_64-macos-none
    └── forge

The output directories used for each binary are determined by a format string: ${name}-v${version}-${target}. You can modify this with additional info at runtime like using date instead of version string: --format "\${name}-$(date +'%Y%M%d')-\${target}".

You can also create a config file by default at ./.forge.cfg that controls the behavior of forge release:

# flags are specified at the top level
nimble # key without value for booleans
format = "${name}-${target}"
outdir = forge-dist

# use sections to list targets/bins with optional args
[target]
x86_64-linux-musl = "--debugInfo:on"
x86_64-linux-gnu

[bin]
src/forge
src/forgecc = "--opt:size" # use a custom flag for this binary

Example:

forge +release --verbose --dryrun

forge +nims

If you prefer to invoke nim directly to compile your program, you can easily extend your existing configuration to rely on forge.

forge +nims will print a nimscript snippet that will interpret compile time defines (--os, --cpu, --d:libc) to inject the necessary compiler/linker flags to forge (zig cc).

Example to optionally enable it for your project:

cat >> config.nims <<EOF
when withDir(thisDir(), fileExists(".forge.nims")):
  when defined(forge): include ".forge.nims"
EOF
forge +nims >  .forge.nims

Then to compile you can define forge and pass the os and cpu flags to nim and a forge specific libc flag.

nim c -d:forge --os:Macosx --cpu:aarch64 src/forge.nim
nim c -d:forge --libc:musl src/forge.nim
nim c -d:forge -d:target:x86_64-linux-musl src/forge.nim

forge +zig

forge is a wrapper around zig and zig cc. If it's called without any of it's known subcommands (all prefixed by "+") or global flags then it will fall back to zig cc. This way we can deploy a single self-invoking binary since the clang.exe specified to nim can't have subcommands.

To invoke the same zig used by forge directly, forwarding all other args, see forge +zig.

Acknowledgements

Thanks to Andrew Kelley and the many zig contributors.