moved crates in lib/ to src/, renamed crates, modified some files' text (#660)

moved crates in lib/ to src/, renamed crates, modified some files' text (#660)

cranelift/codegen/build.rs

@@ -0,0 +1,155 @@
+// Build script.
+//
+// This program is run by Cargo when building cranelift-codegen. It is used to generate Rust code from
+// the language definitions in the cranelift-codegen/meta directory.
+//
+// Environment:
+//
+// OUT_DIR
+//     Directory where generated files should be placed.
+//
+// TARGET
+//     Target triple provided by Cargo.
+//
+// CRANELIFT_TARGETS (Optional)
+//     A setting for conditional compilation of isa targets. Possible values can be "native" or
+//     known isa targets separated by ','.
+//
+// The build script expects to be run from the directory where this build.rs file lives. The
+// current directory is used to find the sources.
+
+use cranelift_codegen_meta as meta;
+
+use crate::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();
+    let cranelift_targets = cranelift_targets.as_ref().map(|s| s.as_ref());
+    let python = identify_python();
+
+    // Configure isa targets cfg.
+    match isa_targets(cranelift_targets, &target_triple) {
+        Ok(isa_targets) => {
+            for isa in &isa_targets {
+                println!("cargo:rustc-cfg=build_{}", isa.to_string());
+            }
+        }
+        Err(err) => {
+            eprintln!("Error: {}", err);
+            process::exit(1);
+        }
+    }
+
+    let cur_dir = env::current_dir().expect("Can't access current working directory");
+    let crate_dir = cur_dir.as_path();
+
+    // Make sure we rebuild if this build script changes.
+    // I guess that won't happen if you have non-UTF8 bytes in your path names.
+    // The `build.py` script prints out its own dependencies.
+    println!(
+        "cargo:rerun-if-changed={}",
+        crate_dir.join("build.rs").to_str().unwrap()
+    );
+
+    // Scripts are in `$crate_dir/meta-python`.
+    let meta_dir = crate_dir.join("meta-python");
+    let build_script = meta_dir.join("build.py");
+
+    // Launch build script with Python. We'll just find python in the path.
+    // Use -B to disable .pyc files, because they cause trouble for vendoring
+    // scripts, and this is a build step that isn't run very often anyway.
+    let status = process::Command::new(python)
+        .current_dir(crate_dir)
+        .arg("-B")
+        .arg(build_script)
+        .arg("--out-dir")
+        .arg(out_dir.clone())
+        .status()
+        .expect("Failed to launch second-level build script; is python installed?");
+    if !status.success() {
+        process::exit(status.code().unwrap());
+    }
+
+    // DEVELOPMENT:
+    // ------------------------------------------------------------------------
+    // Now that the Python build process is complete, generate files that are
+    // emitted by the `meta` crate.
+    // ------------------------------------------------------------------------
+
+    if let Err(err) = generate_meta(&out_dir) {
+        eprintln!("Error: {}", err);
+        process::exit(1);
+    }
+
+    if let Ok(_) = env::var("CRANELIFT_VERBOSE") {
+        println!(
+            "cargo:warning=Build step took {:?}.",
+            Instant::now() - start_time
+        );
+        println!("cargo:warning=Generated files are in {}", out_dir);
+    }
+}
+
+fn generate_meta(out_dir: &str) -> Result<(), meta::error::Error> {
+    let shared_settings = meta::gen_settings::generate_common("new_settings.rs", &out_dir)?;
+    let isas = meta::isa::define_all(&shared_settings);
+
+    meta::gen_types::generate("types.rs", &out_dir)?;
+
+    for isa in &isas {
+        meta::gen_registers::generate(&isa, "registers", &out_dir)?;
+        meta::gen_settings::generate(&isa, "new_settings", &out_dir)?;
+    }
+
+    Ok(())
+}
+
+fn identify_python() -> &'static str {
+    for python in &["python", "python3", "python2.7"] {
+        if process::Command::new(python)
+            .arg("--version")
+            .status()
+            .is_ok()
+        {
+            return python;
+        }
+    }
+    panic!("The Cranelift build requires Python (version 2.7 or version 3)");
+}
+
+/// Returns isa targets to configure conditional compilation.
+fn isa_targets(cranelift_targets: Option<&str>, target_triple: &str) -> Result<Vec<Isa>, String> {
+    match cranelift_targets {
+        Some("native") => Isa::from_arch(target_triple.split('-').next().unwrap())
+            .map(|isa| vec![isa])
+            .ok_or_else(|| {
+                format!(
+                    "no supported isa found for target triple `{}`",
+                    target_triple
+                )
+            }),
+        Some(targets) => {
+            let unknown_isa_targets = targets
+                .split(',')
+                .filter(|target| Isa::new(target).is_none())
+                .collect::<Vec<_>>();
+            let isa_targets = targets.split(',').flat_map(Isa::new).collect::<Vec<_>>();
+            match (unknown_isa_targets.is_empty(), isa_targets.is_empty()) {
+                (true, true) => Ok(Isa::all().to_vec()),
+                (true, _) => Ok(isa_targets),
+                (_, _) => Err(format!(
+                    "unknown isa targets: `{}`",
+                    unknown_isa_targets.join(", ")
+                )),
+            }
+        }
+        None => Ok(Isa::all().to_vec()),
+    }
+}