[build] Move Isa enum to the meta library;

lib/codegen/build.rs

@@ -20,6 +20,7 @@
 
 extern crate cranelift_codegen_meta as meta;
 
+use meta::isa::Isa;
 use std::env;
 use std::process;
 
@@ -99,60 +100,6 @@ fn identify_python() -> &'static str {
     panic!("The Cranelift build requires Python (version 2.7 or version 3)");
 }
 
-/// Represents known ISA target.
-#[derive(Copy, Clone)]
-enum Isa {
-    Riscv,
-    X86,
-    Arm32,
-    Arm64,
-}
-
-impl Isa {
-    /// Creates isa target using name.
-    fn new(name: &str) -> Option<Self> {
-        Isa::all()
-            .iter()
-            .cloned()
-            .filter(|isa| isa.name() == name)
-            .next()
-    }
-
-    /// Creates isa target from arch.
-    fn from_arch(arch: &str) -> Option<Isa> {
-        Isa::all()
-            .iter()
-            .cloned()
-            .filter(|isa| isa.is_arch_applicable(arch))
-            .next()
-    }
-
-    /// Returns all supported isa targets.
-    fn all() -> [Isa; 4] {
-        [Isa::Riscv, Isa::X86, Isa::Arm32, Isa::Arm64]
-    }
-
-    /// Returns name of the isa target.
-    fn name(&self) -> &'static str {
-        match *self {
-            Isa::Riscv => "riscv",
-            Isa::X86 => "x86",
-            Isa::Arm32 => "arm32",
-            Isa::Arm64 => "arm64",
-        }
-    }
-
-    /// Checks if arch is applicable for the isa target.
-    fn is_arch_applicable(&self, arch: &str) -> bool {
-        match *self {
-            Isa::Riscv => arch == "riscv",
-            Isa::X86 => ["x86_64", "i386", "i586", "i686"].contains(&arch),
-            Isa::Arm32 => arch.starts_with("arm") || arch.starts_with("thumb"),
-            Isa::Arm64 => arch == "aarch64",
-        }
-    }
-}
-
 /// Returns isa targets to configure conditional compilation.
 fn isa_targets(cranelift_targets: Option<&str>, target_triple: &str) -> Result<Vec<Isa>, String> {
     match cranelift_targets {

lib/codegen/meta/src/isa/mod.rs

@@ -0,0 +1,53 @@
+/// Represents known ISA target.
+#[derive(Copy, Clone)]
+pub enum Isa {
+    Riscv,
+    X86,
+    Arm32,
+    Arm64,
+}
+
+impl Isa {
+    /// Creates isa target using name.
+    pub fn new(name: &str) -> Option<Self> {
+        Isa::all()
+            .iter()
+            .cloned()
+            .filter(|isa| isa.name() == name)
+            .next()
+    }
+
+    /// Creates isa target from arch.
+    pub fn from_arch(arch: &str) -> Option<Isa> {
+        Isa::all()
+            .iter()
+            .cloned()
+            .filter(|isa| isa.is_arch_applicable(arch))
+            .next()
+    }
+
+    /// Returns all supported isa targets.
+    pub fn all() -> [Isa; 4] {
+        [Isa::Riscv, Isa::X86, Isa::Arm32, Isa::Arm64]
+    }
+
+    /// Returns name of the isa target.
+    pub fn name(&self) -> &'static str {
+        match *self {
+            Isa::Riscv => "riscv",
+            Isa::X86 => "x86",
+            Isa::Arm32 => "arm32",
+            Isa::Arm64 => "arm64",
+        }
+    }
+
+    /// Checks if arch is applicable for the isa target.
+    fn is_arch_applicable(&self, arch: &str) -> bool {
+        match *self {
+            Isa::Riscv => arch == "riscv",
+            Isa::X86 => ["x86_64", "i386", "i586", "i686"].contains(&arch),
+            Isa::Arm32 => arch.starts_with("arm") || arch.starts_with("thumb"),
+            Isa::Arm64 => arch == "aarch64",
+        }
+    }
+}

lib/codegen/meta/src/lib.rs

@@ -1,5 +1,6 @@
 pub mod error;
 pub mod gen_types;
+pub mod isa;
 
 mod base;
 mod cdsl;