[meta] Move source generation responsibility into the meta crate itself;

cranelift/codegen/meta/src/lib.rs

@@ -2,12 +2,70 @@
 mod cdsl;
 
 pub mod error;
-pub mod gen_registers;
-pub mod gen_settings;
-pub mod gen_types;
 pub mod isa;
 
+mod gen_registers;
+mod gen_settings;
+mod gen_types;
+
 mod base;
 mod constant_hash;
 mod srcgen;
 mod unique_table;
+
+pub fn isa_from_arch(arch: &str) -> Result<Vec<isa::Isa>, String> {
+    isa::Isa::from_arch(arch)
+        .ok_or_else(|| format!("no supported isa found for arch `{}`", arch))
+        .and_then(|isa| Ok(vec![isa]))
+}
+
+pub fn isas_from_targets(targets: Vec<&str>) -> Result<Vec<isa::Isa>, String> {
+    type R<'a> = Vec<(&'a str, Option<isa::Isa>)>;
+
+    let (known, unknown): (R, R) = targets
+        .into_iter()
+        .map(|target| (target, isa::Isa::from_name(target)))
+        .partition(|(_, opt_isa)| opt_isa.is_some());
+
+    if !unknown.is_empty() {
+        let unknown_targets = unknown
+            .into_iter()
+            .map(|(target, _)| target)
+            .collect::<Vec<_>>()
+            .join(", ");
+        return Err(format!("unknown isa targets: {}", unknown_targets));
+    }
+
+    let isas = if known.is_empty() {
+        isa::Isa::all().to_vec()
+    } else {
+        known
+            .into_iter()
+            .map(|(_, opt_isa)| opt_isa.unwrap())
+            .collect()
+    };
+
+    Ok(isas)
+}
+
+pub fn all_isas() -> Result<Vec<isa::Isa>, String> {
+    isas_from_targets(vec![])
+}
+
+/// Generates all the Rust source files used in Cranelift from the meta-language.
+pub fn generate(isas: &Vec<isa::Isa>, out_dir: &str) -> Result<(), error::Error> {
+    // Common definitions.
+    let shared_settings = gen_settings::generate_common("new_settings.rs", &out_dir)?;
+
+    gen_types::generate("types.rs", &out_dir)?;
+
+    // Per ISA definitions.
+    let isas = isa::define(isas, &shared_settings);
+
+    for isa in isas {
+        gen_registers::generate(&isa, "registers", &out_dir)?;
+        gen_settings::generate(&isa, "new_settings", &out_dir)?;
+    }
+
+    Ok(())
+}