1 files changed, 130 insertions, 0 deletions

diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
new file mode 100644
index 000000000..3b1e07149
--- /dev/null
+++ b/crates/ra_project_model/src/lib.rs
@@ -0,0 +1,130 @@
+mod cargo_workspace;
+mod sysroot;
+
+use std::path::{Path, PathBuf};
+
+use failure::bail;
+use rustc_hash::FxHashMap;
+
+use ra_db::{CrateGraph, FileId};
+
+pub use crate::{
+    cargo_workspace::{CargoWorkspace, Package, Target, TargetKind},
+    sysroot::Sysroot,
+};
+
+// TODO use proper error enum
+pub type Result<T> = ::std::result::Result<T, ::failure::Error>;
+
+#[derive(Debug, Clone)]
+pub struct ProjectWorkspace {
+    pub cargo: CargoWorkspace,
+    pub sysroot: Sysroot,
+}
+
+impl ProjectWorkspace {
+    pub fn discover(path: &Path) -> Result<ProjectWorkspace> {
+        let cargo_toml = find_cargo_toml(path)?;
+        let cargo = CargoWorkspace::from_cargo_metadata(&cargo_toml)?;
+        let sysroot = Sysroot::discover(&cargo_toml)?;
+        let res = ProjectWorkspace { cargo, sysroot };
+        Ok(res)
+    }
+
+    pub fn to_crate_graph(&self, load: &mut dyn FnMut(&Path) -> Option<FileId>) -> CrateGraph {
+        let mut crate_graph = CrateGraph::default();
+        let mut sysroot_crates = FxHashMap::default();
+        for krate in self.sysroot.crates() {
+            if let Some(file_id) = load(krate.root(&self.sysroot)) {
+                sysroot_crates.insert(krate, crate_graph.add_crate_root(file_id));
+            }
+        }
+        for from in self.sysroot.crates() {
+            for to in from.deps(&self.sysroot) {
+                let name = to.name(&self.sysroot);
+                if let (Some(&from), Some(&to)) =
+                    (sysroot_crates.get(&from), sysroot_crates.get(&to))
+                {
+                    if let Err(_) = crate_graph.add_dep(from, name.into(), to) {
+                        log::error!("cyclic dependency between sysroot crates")
+                    }
+                }
+            }
+        }
+
+        let libstd = self.sysroot.std().and_then(|it| sysroot_crates.get(&it).map(|&it| it));
+
+        let mut pkg_to_lib_crate = FxHashMap::default();
+        let mut pkg_crates = FxHashMap::default();
+        // Next, create crates for each package, target pair
+        for pkg in self.cargo.packages() {
+            let mut lib_tgt = None;
+            for tgt in pkg.targets(&self.cargo) {
+                let root = tgt.root(&self.cargo);
+                if let Some(file_id) = load(root) {
+                    let crate_id = crate_graph.add_crate_root(file_id);
+                    if tgt.kind(&self.cargo) == TargetKind::Lib {
+                        lib_tgt = Some(crate_id);
+                        pkg_to_lib_crate.insert(pkg, crate_id);
+                    }
+                    pkg_crates.entry(pkg).or_insert_with(Vec::new).push(crate_id);
+                }
+            }
+
+            // Set deps to the std and to the lib target of the current package
+            for &from in pkg_crates.get(&pkg).into_iter().flatten() {
+                if let Some(to) = lib_tgt {
+                    if to != from {
+                        if let Err(_) = crate_graph.add_dep(from, pkg.name(&self.cargo).into(), to)
+                        {
+                            log::error!(
+                                "cyclic dependency between targets of {}",
+                                pkg.name(&self.cargo)
+                            )
+                        }
+                    }
+                }
+                if let Some(std) = libstd {
+                    if let Err(_) = crate_graph.add_dep(from, "std".into(), std) {
+                        log::error!("cyclic dependency on std for {}", pkg.name(&self.cargo))
+                    }
+                }
+            }
+        }
+
+        // Now add a dep ednge from all targets of upstream to the lib
+        // target of downstream.
+        for pkg in self.cargo.packages() {
+            for dep in pkg.dependencies(&self.cargo) {
+                if let Some(&to) = pkg_to_lib_crate.get(&dep.pkg) {
+                    for &from in pkg_crates.get(&pkg).into_iter().flatten() {
+                        if let Err(_) = crate_graph.add_dep(from, dep.name.clone().into(), to) {
+                            log::error!(
+                                "cyclic dependency {} -> {}",
+                                pkg.name(&self.cargo),
+                                dep.pkg.name(&self.cargo)
+                            )
+                        }
+                    }
+                }
+            }
+        }
+
+        crate_graph
+    }
+}
+
+fn find_cargo_toml(path: &Path) -> Result<PathBuf> {
+    if path.ends_with("Cargo.toml") {
+        return Ok(path.to_path_buf());
+    }
+    let mut curr = Some(path);
+    while let Some(path) = curr {
+        let candidate = path.join("Cargo.toml");
+        if candidate.exists() {
+            return Ok(candidate);
+        }
+        curr = path.parent();
+    }
+    bail!("can't find Cargo.toml at {}", path.display())
+}