Merge commit '2bb3996244' into sync_cg_clif-2022-12-14

compiler/rustc_codegen_cranelift/build_system/path.rs

@@ -0,0 +1,70 @@
+use std::fs;
+use std::path::PathBuf;
+
+#[derive(Debug, Clone)]
+pub(crate) struct Dirs {
+    pub(crate) source_dir: PathBuf,
+    pub(crate) download_dir: PathBuf,
+    pub(crate) build_dir: PathBuf,
+    pub(crate) dist_dir: PathBuf,
+}
+
+#[doc(hidden)]
+#[derive(Debug, Copy, Clone)]
+pub(crate) enum PathBase {
+    Source,
+    Download,
+    Build,
+    Dist,
+}
+
+impl PathBase {
+    fn to_path(self, dirs: &Dirs) -> PathBuf {
+        match self {
+            PathBase::Source => dirs.source_dir.clone(),
+            PathBase::Download => dirs.download_dir.clone(),
+            PathBase::Build => dirs.build_dir.clone(),
+            PathBase::Dist => dirs.dist_dir.clone(),
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+pub(crate) enum RelPath {
+    Base(PathBase),
+    Join(&'static RelPath, &'static str),
+}
+
+impl RelPath {
+    pub(crate) const SOURCE: RelPath = RelPath::Base(PathBase::Source);
+    pub(crate) const DOWNLOAD: RelPath = RelPath::Base(PathBase::Download);
+    pub(crate) const BUILD: RelPath = RelPath::Base(PathBase::Build);
+    pub(crate) const DIST: RelPath = RelPath::Base(PathBase::Dist);
+
+    pub(crate) const SCRIPTS: RelPath = RelPath::SOURCE.join("scripts");
+    pub(crate) const BUILD_SYSROOT: RelPath = RelPath::SOURCE.join("build_sysroot");
+    pub(crate) const PATCHES: RelPath = RelPath::SOURCE.join("patches");
+
+    pub(crate) const fn join(&'static self, suffix: &'static str) -> RelPath {
+        RelPath::Join(self, suffix)
+    }
+
+    pub(crate) fn to_path(&self, dirs: &Dirs) -> PathBuf {
+        match self {
+            RelPath::Base(base) => base.to_path(dirs),
+            RelPath::Join(base, suffix) => base.to_path(dirs).join(suffix),
+        }
+    }
+
+    pub(crate) fn ensure_exists(&self, dirs: &Dirs) {
+        fs::create_dir_all(self.to_path(dirs)).unwrap();
+    }
+
+    pub(crate) fn ensure_fresh(&self, dirs: &Dirs) {
+        let path = self.to_path(dirs);
+        if path.exists() {
+            fs::remove_dir_all(&path).unwrap();
+        }
+        fs::create_dir_all(path).unwrap();
+    }
+}