diff --git a/src/expr.rs b/src/expr.rs
index efea054..e72888f 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -64,7 +64,7 @@ impl TargetMatcher for targ::TargetInfo {
                 Some(e) => env == e,
                 None => env.0.is_empty(),
             },
-            Family(fam) => Some(fam) == self.family.as_ref(),
+            Family(fam) => self.families.contains(fam),
             Os(os) => Some(os) == self.os.as_ref(),
             PointerWidth(w) => *w == self.pointer_width,
             Vendor(ven) => match &self.vendor {
@@ -211,8 +211,8 @@ impl TargetMatcher for target_lexicon::Triple {
                     Netbsd, None_, Openbsd, Redox, Solaris, Tvos, Uefi, Unknown, VxWorks, Wasi,
                     Windows,
                 };
-                let lexicon_fam = match self.operating_system {
-                    AmdHsa | Bitrig | Cloudabi | Cuda | Hermit | Nebulet | None_ | Uefi => None,
+                match self.operating_system {
+                    AmdHsa | Bitrig | Cloudabi | Cuda | Hermit | Nebulet | None_ | Uefi => false,
                     Darwin
                     | Dragonfly
                     | Espidf
@@ -229,30 +229,39 @@ impl TargetMatcher for target_lexicon::Triple {
                     | Redox
                     | Solaris
                     | Tvos
-                    | VxWorks => Some(crate::targets::Family::unix),
-                    Emscripten | Unknown => {
+                    | VxWorks => fam == &crate::targets::Family::unix,
+                    Emscripten => {
+                        match self.architecture {
+                            // asmjs, wasm32 and wasm64 are part of both the wasm and unix families
+                            Architecture::Asmjs | Architecture::Wasm32 => {
+                                fam == &crate::targets::Family::wasm
+                                    || fam == &crate::targets::Family::unix
+                            }
+                            _ => false,
+                        }
+                    }
+                    Unknown => {
                         // asmjs, wasm32 and wasm64 are part of the wasm family.
                         match self.architecture {
                             Architecture::Asmjs | Architecture::Wasm32 | Architecture::Wasm64 => {
-                                Some(crate::targets::Family::wasm)
+                                fam == &crate::targets::Family::wasm
                             }
-                            _ => None,
+                            _ => false,
                         }
                     }
                     Linux => {
                         // The 'kernel' environment is treated specially as not-unix
                         if self.environment != Environment::Kernel {
-                            Some(crate::targets::Family::unix)
+                            fam == &crate::targets::Family::unix
                         } else {
-                            None
+                            false
                         }
                     }
-                    Wasi => Some(crate::targets::Family::wasm),
-                    Windows => Some(crate::targets::Family::windows),
+                    Wasi => fam == &crate::targets::Family::wasm,
+                    Windows => fam == &crate::targets::Family::windows,
                     // I really dislike non-exhaustive :(
-                    _ => None,
-                };
-                Some(fam) == lexicon_fam.as_ref()
+                    _ => false,
+                }
             }
             Os(os) => match os.0.parse::<OperatingSystem>() {
                 Ok(o) => match self.environment {
diff --git a/src/targets.rs b/src/targets.rs
index 0ef7f6e..709e1c7 100644
--- a/src/targets.rs
+++ b/src/targets.rs
@@ -1,5 +1,5 @@
 use crate::error::Reason;
-use std::borrow::Cow;
+use std::{borrow::Cow, ops::Deref};
 
 mod builtins;
 
@@ -24,8 +24,8 @@ pub struct Vendor(pub Cow<'static, str>);
 #[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct Os(pub Cow<'static, str>);
 
-/// The target family, which describes a set of targets grouped in some logical manner, typically by
-/// operating system. This includes values like `unix` and `windows`.
+/// Individual target families, which describe a set of targets grouped in some logical manner,
+/// typically by operating system. This includes values like `unix` and `windows`.
 #[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct Family(pub Cow<'static, str>);
 
@@ -81,6 +81,70 @@ field_impls!(Os);
 field_impls!(Family);
 field_impls!(Env);
 
+/// A set of families for a target.
+///
+/// Each target can be part of one or more families. This struct represents them.
+#[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+pub struct Families(Cow<'static, [Family]>);
+
+impl Families {
+    /// Constructs a new instance.
+    ///
+    /// This method accepts both owned `String`s and `&'static str`s.
+    ///
+    /// If you have a `&'static [&'static str]`, prefer [`Self::new_const`].
+    #[inline]
+    pub fn new(val: impl IntoIterator<Item = Family>) -> Self {
+        let mut families: Vec<_> = val.into_iter().collect();
+        families.sort_unstable();
+        Self(Cow::Owned(families))
+    }
+
+    /// Constructs a new instance of this field from a static slice of `&'static str`.
+    ///
+    /// `val` must be in sorted order: this constructor cannot check for that due to
+    /// limitations in current versions of Rust.
+    #[inline]
+    pub const fn new_const(val: &'static [Family]) -> Self {
+        // TODO: Check that val is sorted.
+        Self(Cow::Borrowed(val))
+    }
+
+    /// Returns true if this list of families contains a given family.
+    pub fn contains(&self, val: &Family) -> bool {
+        // This relies on the sorted-ness of its contents.
+        self.0.binary_search(val).is_ok()
+    }
+}
+
+impl Deref for Families {
+    type Target = [Family];
+    fn deref(&self) -> &Self::Target {
+        &*self.0
+    }
+}
+
+impl AsRef<[Family]> for Families {
+    #[inline]
+    fn as_ref(&self) -> &[Family] {
+        &*self.0
+    }
+}
+
+impl std::fmt::Display for Families {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{{")?;
+        let len = self.0.len();
+        for (idx, family) in self.0.iter().enumerate() {
+            write!(f, "{}", family)?;
+            if idx + 1 < len {
+                write!(f, ", ")?;
+            }
+        }
+        write!(f, "}}")
+    }
+}
+
 macro_rules! target_enum {
     (
         $(#[$outer:meta])*
@@ -162,10 +226,10 @@ pub struct TargetInfo {
     /// [target_vendor](https://doc.rust-lang.org/reference/conditional-compilation.html#target_vendor)
     /// predicate.
     pub vendor: Option<Vendor>,
-    /// The target's family, if any. Used by the
+    /// The target's families, if any. Used by the
     /// [target_family](https://doc.rust-lang.org/reference/conditional-compilation.html#target_family)
     /// predicate.
-    pub family: Option<Family>,
+    pub families: Families,
     /// The size of the target's pointer type. Used by the
     /// [target_pointer_width](https://doc.rust-lang.org/reference/conditional-compilation.html#target_pointer_width)
     /// predicate.
diff --git a/src/targets/builtins.rs b/src/targets/builtins.rs
index 6e8060a..07e0329 100644
--- a/src/targets/builtins.rs
+++ b/src/targets/builtins.rs
@@ -19,7 +19,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -29,7 +29,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -39,7 +39,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -49,7 +49,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -59,7 +59,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -69,7 +69,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -79,7 +79,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::kmc),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -89,7 +89,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -99,7 +99,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: Some(Env::msvc),
         vendor: Some(Vendor::pc),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -109,7 +109,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -119,7 +119,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -129,7 +129,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -139,7 +139,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -149,7 +149,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -159,7 +159,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -169,7 +169,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -179,7 +179,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -189,7 +189,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -199,7 +199,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: Some(Env::relibc),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -209,7 +209,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -219,7 +219,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: Some(Env::msvc),
         vendor: Some(Vendor::uwp),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -229,7 +229,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::wrs),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -239,7 +239,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -249,7 +249,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::aarch64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -259,7 +259,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -269,7 +269,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -279,7 +279,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -289,7 +289,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -299,7 +299,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -309,7 +309,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -319,7 +319,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -329,7 +329,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -339,7 +339,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -349,7 +349,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -359,7 +359,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::uclibc),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -369,7 +369,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnueabihf),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -379,7 +379,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::eabihf),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -389,7 +389,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::newlib),
         vendor: Some(Vendor::nintendo),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -399,7 +399,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -409,7 +409,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -419,7 +419,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnueabihf),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -429,7 +429,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -439,7 +439,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -449,7 +449,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -459,7 +459,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -469,7 +469,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::uclibc),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -479,7 +479,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::eabihf),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -489,7 +489,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnu),
         vendor: Some(Vendor::wrs),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -499,7 +499,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::kmc),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -509,7 +509,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::kmc),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -519,7 +519,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -529,7 +529,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -539,7 +539,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -549,7 +549,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -559,7 +559,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -569,7 +569,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::wasm32,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::wasm),
+        families: Families::unix_wasm,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -579,7 +579,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::avr,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 16,
         endian: Endian::little,
     },
@@ -589,7 +589,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::bpf,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -599,7 +599,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::bpf,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -609,7 +609,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::hexagon,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -619,7 +619,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -629,7 +629,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::msvc),
         vendor: Some(Vendor::pc),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -639,7 +639,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -649,7 +649,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -659,7 +659,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -669,7 +669,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -679,7 +679,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::gnu),
         vendor: Some(Vendor::pc),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -689,7 +689,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::msvc),
         vendor: Some(Vendor::pc),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -699,7 +699,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -709,7 +709,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -719,7 +719,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -729,7 +729,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -739,7 +739,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -749,7 +749,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -759,7 +759,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -769,7 +769,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::gnu),
         vendor: Some(Vendor::uwp),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -779,7 +779,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::msvc),
         vendor: Some(Vendor::uwp),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -789,7 +789,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86,
         env: Some(Env::gnu),
         vendor: Some(Vendor::wrs),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -799,7 +799,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::m68k,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -809,7 +809,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -819,7 +819,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -829,7 +829,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: Some(Env::uclibc),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -839,7 +839,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -849,7 +849,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips64,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -859,7 +859,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -869,7 +869,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips64,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -879,7 +879,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: None,
         vendor: Some(Vendor::sony),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -889,7 +889,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -899,7 +899,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -909,7 +909,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: Some(Env::uclibc),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -919,7 +919,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -929,7 +929,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -939,7 +939,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -949,7 +949,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -959,7 +959,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::mips64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -969,7 +969,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::msp430,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 16,
         endian: Endian::little,
     },
@@ -979,7 +979,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::nvptx64,
         env: None,
         vendor: Some(Vendor::nvidia),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -989,7 +989,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -999,7 +999,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -1009,7 +1009,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -1019,7 +1019,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -1029,7 +1029,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -1039,7 +1039,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -1049,7 +1049,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc,
         env: Some(Env::gnu),
         vendor: Some(Vendor::wrs),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -1059,7 +1059,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc,
         env: Some(Env::gnu),
         vendor: Some(Vendor::wrs),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -1069,7 +1069,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1079,7 +1079,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1089,7 +1089,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc64,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1099,7 +1099,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::wrs),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1109,7 +1109,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1119,7 +1119,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1129,7 +1129,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::powerpc64,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1139,7 +1139,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv32,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1149,7 +1149,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv32,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1159,7 +1159,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv32,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1169,7 +1169,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv32,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1179,7 +1179,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv32,
         env: Some(Env::newlib),
         vendor: Some(Vendor::espressif),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1189,7 +1189,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv32,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1199,7 +1199,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1209,7 +1209,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv64,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1219,7 +1219,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1229,7 +1229,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::riscv64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1239,7 +1239,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::s390x,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1249,7 +1249,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::s390x,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1259,7 +1259,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::sparc,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::big,
     },
@@ -1269,7 +1269,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::sparc64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1279,7 +1279,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::sparc64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1289,7 +1289,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::sparc64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1299,7 +1299,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::sparc64,
         env: None,
         vendor: Some(Vendor::sun),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::big,
     },
@@ -1309,7 +1309,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1319,7 +1319,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1329,7 +1329,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::msvc),
         vendor: Some(Vendor::pc),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1339,7 +1339,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::msvc),
         vendor: Some(Vendor::uwp),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1349,7 +1349,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1359,7 +1359,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1369,7 +1369,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1379,7 +1379,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1389,7 +1389,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1399,7 +1399,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1409,7 +1409,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1419,7 +1419,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1429,7 +1429,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::arm,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1439,7 +1439,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::wasm32,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::wasm),
+        families: Families::unix_wasm,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1449,7 +1449,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::wasm32,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::wasm),
+        families: Families::wasm,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1459,7 +1459,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::wasm32,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::wasm),
+        families: Families::wasm,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1469,7 +1469,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::wasm64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::wasm),
+        families: Families::wasm,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1479,7 +1479,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1489,7 +1489,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1499,7 +1499,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1509,7 +1509,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::apple),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1519,7 +1519,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::sgx),
         vendor: Some(Vendor::fortanix),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1529,7 +1529,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1539,7 +1539,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1549,7 +1549,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::pc),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1559,7 +1559,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::pc),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1569,7 +1569,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::msvc),
         vendor: Some(Vendor::pc),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1579,7 +1579,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::sun),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1589,7 +1589,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1599,7 +1599,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1609,7 +1609,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1619,7 +1619,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1629,7 +1629,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1639,7 +1639,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::uclibc),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1649,7 +1649,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1659,7 +1659,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 32,
         endian: Endian::little,
     },
@@ -1669,7 +1669,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::musl),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1679,7 +1679,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1689,7 +1689,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1699,7 +1699,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1709,7 +1709,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1719,7 +1719,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1729,7 +1729,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::relibc),
         vendor: Some(Vendor::unknown),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1739,7 +1739,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: None,
         vendor: Some(Vendor::unknown),
-        family: None,
+        families: Families::new_const(&[]),
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1749,7 +1749,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::uwp),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1759,7 +1759,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::msvc),
         vendor: Some(Vendor::uwp),
-        family: Some(Family::windows),
+        families: Families::windows,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1769,7 +1769,7 @@ pub const ALL_BUILTINS: &[TargetInfo] = &[
         arch: Arch::x86_64,
         env: Some(Env::gnu),
         vendor: Some(Vendor::wrs),
-        family: Some(Family::unix),
+        families: Families::unix,
         pointer_width: 64,
         endian: Endian::little,
     },
@@ -1850,6 +1850,18 @@ impl super::Family {
     pub const windows: Family = Family::new_const("windows");
 }
 
+const __families_unix: &[Family] = &[Family::unix];
+const __families_unix_wasm: &[Family] = &[Family::unix, Family::wasm];
+const __families_wasm: &[Family] = &[Family::wasm];
+const __families_windows: &[Family] = &[Family::windows];
+
+impl super::Families {
+    pub const unix: Families = Families::new_const(__families_unix);
+    pub const unix_wasm: Families = Families::new_const(__families_unix_wasm);
+    pub const wasm: Families = Families::new_const(__families_wasm);
+    pub const windows: Families = Families::new_const(__families_windows);
+}
+
 impl super::Env {
     pub const eabihf: Env = Env::new_const("eabihf");
     pub const gnu: Env = Env::new_const("gnu");
diff --git a/tests/eval.rs b/tests/eval.rs
index e3a509b..c43f7ec 100644
--- a/tests/eval.rs
+++ b/tests/eval.rs
@@ -117,16 +117,12 @@ fn target_family() {
 
     for target in all {
         let target = Target::make(target.triple.as_str());
-        match target.builtin.family {
-            Some(_) => {
-                assert!(matches_any_family.eval(|pred| { tg_match!(pred, target) }));
-                assert!(!impossible.eval(|pred| { tg_match!(pred, target) }));
-            }
-            None => {
-                assert!(!matches_any_family.eval(|pred| { tg_match!(pred, target) }));
-                assert!(!impossible.eval(|pred| { tg_match!(pred, target) }));
-            }
+        if target.builtin.families.is_empty() {
+            assert!(!matches_any_family.eval(|pred| { tg_match!(pred, target) }));
+        } else {
+            assert!(matches_any_family.eval(|pred| { tg_match!(pred, target) }));
         }
+        assert!(!impossible.eval(|pred| { tg_match!(pred, target) }));
     }
 }
 
diff --git a/update/src/main.rs b/update/src/main.rs
index 94195a0..45efda2 100644
--- a/update/src/main.rs
+++ b/update/src/main.rs
@@ -90,6 +90,7 @@ fn real_main() -> Result<(), String> {
     let mut oses: Vec<String> = Vec::new();
     let mut envs: Vec<String> = Vec::new();
     let mut families: Vec<String> = Vec::new();
+    let mut family_groups: Vec<Vec<String>> = Vec::new();
 
     for target in targets.lines() {
         let output = Command::new(&rustc)
@@ -115,7 +116,7 @@ fn real_main() -> Result<(), String> {
         let mut arch = None;
         let mut endian = None;
         let mut env = None;
-        let mut family = None;
+        let mut family_group = Vec::new();
         let mut os = None;
         let mut width = None;
         let mut vendor = None;
@@ -143,7 +144,7 @@ fn real_main() -> Result<(), String> {
                                 env = Some(val)
                             }
                         }
-                        "family" => family = Some(val),
+                        "family" => family_group.push(val),
                         "feature" => {
 
                             // num_feats += 1;
@@ -188,7 +189,28 @@ fn real_main() -> Result<(), String> {
         insert(vendor, &mut vendors);
         insert(os, &mut oses);
         insert(env, &mut envs);
-        insert(family, &mut families);
+
+        // Family groups require special handling.
+        family_group.sort_unstable();
+        for family in &family_group {
+            insert(Some(family), &mut families);
+        }
+
+        if !family_group.is_empty() {
+            // Can't compare Vec<String> to Vec<&str> so have to do this comparison.
+            let family_group: Vec<String> = family_group.iter().map(|&s| s.to_owned()).collect();
+            if let Err(i) = family_groups.binary_search_by(|t| t.cmp(&family_group)) {
+                family_groups.insert(i, family_group);
+            }
+        }
+
+        let families_str = if family_group.is_empty() {
+            "Families::new_const(&[])".to_owned()
+        } else {
+            let mut families_str = "Families::".to_owned();
+            write_family_group_str(&mut families_str, family_group.iter().copied());
+            families_str
+        };
 
         writeln!(
             out,
@@ -198,7 +220,7 @@ fn real_main() -> Result<(), String> {
         arch: Arch::{arch},
         env: {env},
         vendor: {vendor},
-        family: {family},
+        families: {families_str},
         pointer_width: {width},
         endian: Endian::{endian},
     }},",
@@ -213,9 +235,6 @@ fn real_main() -> Result<(), String> {
             vendor = vendor
                 .map(|v| format!("Some(Vendor::{})", v))
                 .unwrap_or_else(|| "None".to_owned()),
-            family = family
-                .map(|f| format!("Some(Family::{})", f))
-                .unwrap_or_else(|| "None".to_owned()),
             width = width.expect("target had no pointer_width"),
             endian = endian.expect("target had no endian"),
         )
@@ -228,6 +247,7 @@ fn real_main() -> Result<(), String> {
     write_impls(&mut out, "Vendor", vendors);
     write_impls(&mut out, "Os", oses);
     write_impls(&mut out, "Family", families);
+    write_families_impls(&mut out, family_groups);
     write_impls(&mut out, "Env", envs);
 
     std::fs::write("src/targets/builtins.rs", out)
@@ -260,6 +280,45 @@ fn write_impls(out: &mut String, typ: &'static str, builtins: Vec<String>) {
     writeln!(out, "}}").unwrap();
 }
 
+fn write_families_impls(out: &mut String, family_groups: Vec<Vec<String>>) {
+    writeln!(out).unwrap();
+    for family_group in &family_groups {
+        write!(out, "const __families_").unwrap();
+        write_family_group_str(out, family_group.iter().map(|s| s.as_str()));
+        write!(out, ": &[Family] = ").unwrap();
+        write!(out, "&[").unwrap();
+        for family in family_group {
+            writeln!(out, "Family::{}, ", family).unwrap();
+        }
+        writeln!(out, "];").unwrap();
+    }
+
+    writeln!(out, "\nimpl super::Families {{").unwrap();
+
+    for family_group in family_groups {
+        write!(out, "pub const ").unwrap();
+        write_family_group_str(out, family_group.iter().map(|s| s.as_str()));
+        write!(out, ": Families = Families::new_const(__families_").unwrap();
+        write_family_group_str(out, family_group.iter().map(|s| s.as_str()));
+        writeln!(out, ");").unwrap();
+    }
+
+    writeln!(out, "}}").unwrap();
+}
+
+fn write_family_group_str<'a>(
+    out: &mut String,
+    family_group: impl IntoIterator<Item = &'a str> + ExactSizeIterator,
+) {
+    let len = family_group.len();
+    for (idx, family) in family_group.into_iter().enumerate() {
+        out.push_str(family);
+        if idx < len - 1 {
+            out.push_str("_");
+        }
+    }
+}
+
 fn main() {
     // Workaround for https://github.com/rust-lang/rust/issues/36156
     // the ios targets attempt to find an SDK path, and then just hide