Macro cfg_aliases::cfg_aliases
source ยท macro_rules! cfg_aliases { (@cfg_is_set $cfgname:ident) => { ... }; (@cfg_has_feature $feature:expr) => { ... }; (@cfg_contains $cfgname:ident = $cfgvalue:expr) => { ... }; ( @parser_emit all $({$($grouped:tt)+})+ ) => { ... }; ( @parser_emit any $({$($grouped:tt)+})+ ) => { ... }; ( @parser_clause $op:ident [$({$($grouped:tt)+})*] [, $($rest:tt)*] $($current:tt)+ ) => { ... }; ( @parser_clause $op:ident [$({$($grouped:tt)+})*] [$tok:tt $($rest:tt)*] $($current:tt)* ) => { ... }; ( @parser_clause $op:ident [$({$($grouped:tt)+})*] [] $($current:tt)+ ) => { ... }; ( @parser all($($tokens:tt)+) ) => { ... }; ( @parser any($($tokens:tt)+) ) => { ... }; ( @parser not($($tokens:tt)+) ) => { ... }; (@parser feature = $value:expr) => { ... }; (@parser $key:ident = $value:expr) => { ... }; (@parser $e:ident) => { ... }; ( @with_dollar[$dol:tt] $( $alias:ident : { $($config:tt)* } ),* $(,)? ) => { ... }; ($($tokens:tt)*) => { ... }; }
Expand description
Create cfg
aliases
build.rs:
// Setup cfg aliases
cfg_aliases! {
// Platforms
wasm: { target_arch = "wasm32" },
android: { target_os = "android" },
macos: { target_os = "macos" },
linux: { target_os = "linux" },
// Backends
surfman: { all(unix, feature = "surfman", not(wasm)) },
glutin: { all(feature = "glutin", not(wasm)) },
wgl: { all(windows, feature = "wgl", not(wasm)) },
dummy: { not(any(wasm, glutin, wgl, surfman)) },
}
After you put this in your build script you can then check for those conditions like so:
#[cfg(surfman)]
{
// Do stuff related to surfman
}
#[cfg(dummy)]
println!("We're in dummy mode, specify another feature if you want a smarter app!");
This greatly improves what would otherwise look like this without the aliases:
#[cfg(all(unix, feature = "surfman", not(target_arch = "wasm32")))]
{
// Do stuff related to surfman
}
#[cfg(not(any(
target_arch = "wasm32",
all(unix, feature = "surfman", not(target_arch = "wasm32")),
all(windows, feature = "wgl", not(target_arch = "wasm32")),
all(feature = "glutin", not(target_arch = "wasm32")),
)))]
println!("We're in dummy mode, specify another feature if you want a smarter app!");