[build] Implement registers code generation in the Rust meta crate;

lib/codegen/build.rs

@@ -24,7 +24,11 @@ use meta::isa::Isa;
 use std::env;
 use std::process;
 
+use std::time::Instant;
+
 fn main() {
+    let start_time = Instant::now();
+
     let out_dir = env::var("OUT_DIR").expect("The OUT_DIR environment variable must be set");
     let target_triple = env::var("TARGET").expect("The TARGET environment variable must be set");
     let cranelift_targets = env::var("CRANELIFT_TARGETS").ok();
@@ -35,7 +39,7 @@ fn main() {
     match isa_targets(cranelift_targets, &target_triple) {
         Ok(isa_targets) => {
             for isa in &isa_targets {
-                println!("cargo:rustc-cfg=build_{}", isa.name());
+                println!("cargo:rustc-cfg=build_{}", isa.to_string());
             }
         }
         Err(err) => {
@@ -44,8 +48,6 @@ fn main() {
         }
     }
 
-    println!("Build script generating files in {}", out_dir);
-
     let cur_dir = env::current_dir().expect("Can't access current working directory");
     let crate_dir = cur_dir.as_path();
 
@@ -81,10 +83,28 @@ fn main() {
     // Now that the Python build process is complete, generate files that are
     // emitted by the `meta` crate.
     // ------------------------------------------------------------------------
+    let isas = meta::isa::define_all();
+
     if let Err(err) = meta::gen_types::generate("types.rs", &out_dir) {
         eprintln!("Error: {}", err);
         process::exit(1);
     }
+
+    for isa in isas {
+        if let Err(err) = meta::gen_registers::generate(isa, "new_registers", &out_dir) {
+            eprintln!("Error: {}", err);
+            process::exit(1);
+        }
+    }
+
+    println!(
+        "cargo:warning=Cranelift meta-build step took {:?}",
+        Instant::now() - start_time
+    );
+    println!(
+        "cargo:warning=Meta-build script generated files in {}",
+        out_dir
+    );
 }
 
 fn identify_python() -> &'static str {