Refactor build script data

1 files changed, 206 insertions, 0 deletions

diff --git a/crates/project_model/src/build_data.rs b/crates/project_model/src/build_data.rs
new file mode 100644
index 000000000..82fcf23ad
--- /dev/null
+++ b/crates/project_model/src/build_data.rs
@@ -0,0 +1,206 @@
+//! Handles build script specific information
+
+use std::{
+    ffi::OsStr,
+    io::BufReader,
+    path::{Path, PathBuf},
+    process::{Command, Stdio},
+};
+
+use anyhow::Result;
+use cargo_metadata::{BuildScript, Message, Package, PackageId};
+use itertools::Itertools;
+use paths::AbsPathBuf;
+use rustc_hash::FxHashMap;
+use stdx::JodChild;
+
+use crate::{cfg_flag::CfgFlag, CargoConfig};
+
+#[derive(Debug, Clone, Default)]
+pub(crate) struct BuildDataMap {
+    data: FxHashMap<PackageId, BuildData>,
+}
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+pub struct BuildData {
+    /// List of config flags defined by this package's build script
+    pub cfgs: Vec<CfgFlag>,
+    /// List of cargo-related environment variables with their value
+    ///
+    /// If the package has a build script which defines environment variables,
+    /// they can also be found here.
+    pub envs: Vec<(String, String)>,
+    /// Directory where a build script might place its output
+    pub out_dir: Option<AbsPathBuf>,
+    /// Path to the proc-macro library file if this package exposes proc-macros
+    pub proc_macro_dylib_path: Option<AbsPathBuf>,
+}
+
+impl BuildDataMap {
+    pub(crate) fn new(
+        cargo_toml: &Path,
+        cargo_features: &CargoConfig,
+        packages: &Vec<Package>,
+        progress: &dyn Fn(String),
+    ) -> Result<BuildDataMap> {
+        let mut cmd = Command::new(toolchain::cargo());
+        cmd.args(&["check", "--workspace", "--message-format=json", "--manifest-path"])
+            .arg(cargo_toml);
+
+        // --all-targets includes tests, benches and examples in addition to the
+        // default lib and bins. This is an independent concept from the --targets
+        // flag below.
+        cmd.arg("--all-targets");
+
+        if let Some(target) = &cargo_features.target {
+            cmd.args(&["--target", target]);
+        }
+
+        if cargo_features.all_features {
+            cmd.arg("--all-features");
+        } else {
+            if cargo_features.no_default_features {
+                // FIXME: `NoDefaultFeatures` is mutual exclusive with `SomeFeatures`
+                // https://github.com/oli-obk/cargo_metadata/issues/79
+                cmd.arg("--no-default-features");
+            }
+            if !cargo_features.features.is_empty() {
+                cmd.arg("--features");
+                cmd.arg(cargo_features.features.join(" "));
+            }
+        }
+
+        cmd.stdout(Stdio::piped()).stderr(Stdio::null()).stdin(Stdio::null());
+
+        let mut child = cmd.spawn().map(JodChild)?;
+        let child_stdout = child.stdout.take().unwrap();
+        let stdout = BufReader::new(child_stdout);
+
+        let mut res = BuildDataMap::default();
+        for message in cargo_metadata::Message::parse_stream(stdout) {
+            if let Ok(message) = message {
+                match message {
+                    Message::BuildScriptExecuted(BuildScript {
+                        package_id,
+                        out_dir,
+                        cfgs,
+                        env,
+                        ..
+                    }) => {
+                        let cfgs = {
+                            let mut acc = Vec::new();
+                            for cfg in cfgs {
+                                match cfg.parse::<CfgFlag>() {
+                                    Ok(it) => acc.push(it),
+                                    Err(err) => {
+                                        anyhow::bail!("invalid cfg from cargo-metadata: {}", err)
+                                    }
+                                };
+                            }
+                            acc
+                        };
+                        let res = res.data.entry(package_id.clone()).or_default();
+                        // cargo_metadata crate returns default (empty) path for
+                        // older cargos, which is not absolute, so work around that.
+                        if out_dir != PathBuf::default() {
+                            let out_dir = AbsPathBuf::assert(out_dir);
+                            res.out_dir = Some(out_dir);
+                            res.cfgs = cfgs;
+                        }
+
+                        res.envs = env;
+                    }
+                    Message::CompilerArtifact(message) => {
+                        progress(format!("metadata {}", message.target.name));
+
+                        if message.target.kind.contains(&"proc-macro".to_string()) {
+                            let package_id = message.package_id;
+                            // Skip rmeta file
+                            if let Some(filename) =
+                                message.filenames.iter().find(|name| is_dylib(name))
+                            {
+                                let filename = AbsPathBuf::assert(filename.clone());
+                                let res = res.data.entry(package_id.clone()).or_default();
+                                res.proc_macro_dylib_path = Some(filename);
+                            }
+                        }
+                    }
+                    Message::CompilerMessage(message) => {
+                        progress(message.target.name.clone());
+                    }
+                    Message::Unknown => (),
+                    Message::BuildFinished(_) => {}
+                    Message::TextLine(_) => {}
+                }
+            }
+        }
+        res.inject_cargo_env(packages);
+        Ok(res)
+    }
+
+    pub(crate) fn with_cargo_env(packages: &Vec<Package>) -> Self {
+        let mut res = Self::default();
+        res.inject_cargo_env(packages);
+        res
+    }
+
+    pub(crate) fn get(&self, id: &PackageId) -> Option<&BuildData> {
+        self.data.get(id)
+    }
+
+    fn inject_cargo_env(&mut self, packages: &Vec<Package>) {
+        for meta_pkg in packages {
+            let resource = self.data.entry(meta_pkg.id.clone()).or_default();
+            inject_cargo_env(meta_pkg, &mut resource.envs);
+
+            if let Some(out_dir) = &resource.out_dir {
+                // NOTE: cargo and rustc seem to hide non-UTF-8 strings from env! and option_env!()
+                if let Some(out_dir) = out_dir.to_str().map(|s| s.to_owned()) {
+                    resource.envs.push(("OUT_DIR".to_string(), out_dir));
+                }
+            }
+        }
+    }
+}
+
+// FIXME: File a better way to know if it is a dylib
+fn is_dylib(path: &Path) -> bool {
+    match path.extension().and_then(OsStr::to_str).map(|it| it.to_string().to_lowercase()) {
+        None => false,
+        Some(ext) => matches!(ext.as_str(), "dll" | "dylib" | "so"),
+    }
+}
+
+/// Recreates the compile-time environment variables that Cargo sets.
+///
+/// Should be synced with <https://doc.rust-lang.org/cargo/reference/environment-variables.html#environment-variables-cargo-sets-for-crates>
+fn inject_cargo_env(package: &cargo_metadata::Package, env: &mut Vec<(String, String)>) {
+    // FIXME: Missing variables:
+    // CARGO, CARGO_PKG_HOMEPAGE, CARGO_CRATE_NAME, CARGO_BIN_NAME, CARGO_BIN_EXE_<name>
+
+    let mut manifest_dir = package.manifest_path.clone();
+    manifest_dir.pop();
+    if let Some(cargo_manifest_dir) = manifest_dir.to_str() {
+        env.push(("CARGO_MANIFEST_DIR".into(), cargo_manifest_dir.into()));
+    }
+
+    env.push(("CARGO_PKG_VERSION".into(), package.version.to_string()));
+    env.push(("CARGO_PKG_VERSION_MAJOR".into(), package.version.major.to_string()));
+    env.push(("CARGO_PKG_VERSION_MINOR".into(), package.version.minor.to_string()));
+    env.push(("CARGO_PKG_VERSION_PATCH".into(), package.version.patch.to_string()));
+
+    let pre = package.version.pre.iter().map(|id| id.to_string()).format(".");
+    env.push(("CARGO_PKG_VERSION_PRE".into(), pre.to_string()));
+
+    let authors = package.authors.join(";");
+    env.push(("CARGO_PKG_AUTHORS".into(), authors));
+
+    env.push(("CARGO_PKG_NAME".into(), package.name.clone()));
+    env.push(("CARGO_PKG_DESCRIPTION".into(), package.description.clone().unwrap_or_default()));
+    //env.push(("CARGO_PKG_HOMEPAGE".into(), package.homepage.clone().unwrap_or_default()));
+    env.push(("CARGO_PKG_REPOSITORY".into(), package.repository.clone().unwrap_or_default()));
+    env.push(("CARGO_PKG_LICENSE".into(), package.license.clone().unwrap_or_default()));
+
+    let license_file =
+        package.license_file.as_ref().map(|buf| buf.display().to_string()).unwrap_or_default();
+    env.push(("CARGO_PKG_LICENSE_FILE".into(), license_file));
+}