Merge #684

684: enable cargo workspace and path dependencies to work seamlessly r=Alexhuszagh a=Emilgardis

This will allow cargo workspaces to work seamlessly with cross, assuming they don't reference anything outside the current workspace root. This change also automatically mounts (if needed) path dependencies.

If they do reference things outside the workspace root, and that fact is not know to `cargo metadata` (e.g, it's not a workspace member or a path dependency), you'll have to mount it with

```toml
[build.env]
volumes = ["THING"]
```

and set `$THING="/path/to/thing"` (we need to work on accessibility for this feature too, a lot of reported issues are solved by it)

I'm sure there is an issue directly related to workspaces, but I can't find any.

fixes #388 

Co-authored-by: Emil Gardström <emil.gardstrom@gmail.com>
Co-authored-by: wngr <oliver@wngr.de>
Co-authored-by: Alexander Huszagh <ahuszagh@gmail.com>

CHANGELOG.md

@@ -16,6 +16,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - #543 - Added environment variables to control the UID and GID in the container
 - #524 - docker: Add Nix Store volume support
 - Added support for mounting volumes.
+- #684 - Enable cargo workspaces to work from any path in the workspace, and make path dependencies mount seamlessly.
 
 ### Changed
 
@@ -45,6 +46,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Re-enabled `sparc64-unknown-linux-gnu` image
 - #582 - Added `libprocstat.so` to FreeBSD images
 - #665 - when not using [env.volumes](https://github.com/cross-rs/cross#mounting-volumes-into-the-build-environment), mount project in /project
+- #494 - Parse Cargo's --manifest-path option to determine mounted docker root
 
 
 ### Removed

README.md

@@ -362,12 +362,6 @@ $ QEMU_STRACE=1 cross run --target aarch64-unknown-linux-gnu
 9 exit_group(0)
 ```
 
-## Caveats
-
-- path dependencies (in Cargo.toml) that point outside the Cargo project won't
-  work because `cross` use docker containers only mounts the Cargo project so
-  the container doesn't have access to the rest of the filesystem.
-
 ## Minimum Supported Rust Version (MSRV)
 
 This crate is guaranteed to compile on stable Rust 1.58.1 and up. It *might*

ci/test.sh

@@ -25,6 +25,14 @@ function retry {
   return ${exit_code}
 }
 
+workspace_test() {
+  # "${@}" is an unbound variable for bash 3.2, which is the installed version on macOS
+  cross build --target "${TARGET}" --workspace "$@"
+  cross run --target "${TARGET}" -p binary "$@"
+  cross run --target "${TARGET}" --bin dependencies \
+    --features=dependencies "$@"
+}
+
 main() {
     local td=
 
@@ -135,6 +143,21 @@ EOF
                 popd
 
                 rm -rf "${td}"
+                td=$(mktemp -d)
+                git clone \
+                    --depth 1 \
+                    --recursive \
+                    https://github.com/cross-rs/test-workspace "${td}"
+
+                pushd "${td}"
+                TARGET="${TARGET}" workspace_test --manifest-path="./workspace/Cargo.toml"
+                pushd "workspace"
+                TARGET="${TARGET}" workspace_test
+                pushd "binary"
+                cross run --target "${TARGET}"
+                popd
+                popd
+                popd
             ;;
         esac
 

src/cargo.rs

@@ -1,7 +1,8 @@
+use serde::Deserialize;
 use std::path::{Path, PathBuf};
 use std::process::{Command, ExitStatus};
-use std::{env, fs};
 
+use crate::cli::Args;
 use crate::errors::*;
 use crate::extensions::CommandExt;
 
@@ -52,38 +53,90 @@ impl<'a> From<&'a str> for Subcommand {
     }
 }
 
-#[derive(Debug)]
-pub struct Root {
-    path: PathBuf,
+#[derive(Debug, Deserialize)]
+pub struct CargoMetadata {
+    pub workspace_root: PathBuf,
+    pub target_directory: PathBuf,
+    pub packages: Vec<Package>,
+    pub workspace_members: Vec<String>,
 }
 
-impl Root {
-    pub fn path(&self) -> &Path {
-        &self.path
+impl CargoMetadata {
+    fn non_workspace_members(&self) -> impl Iterator<Item = &Package> {
+        self.packages
+            .iter()
+            .filter(|p| !self.workspace_members.iter().any(|m| m == &p.id))
     }
-}
 
-/// Cargo project root
-pub fn root() -> Result<Option<Root>> {
-    let cd = env::current_dir().wrap_err("couldn't get current directory")?;
+    pub fn path_dependencies(&self) -> impl Iterator<Item = &Path> {
+        // TODO: Also filter out things that are in workspace, but not a workspace member
+        self.non_workspace_members().filter_map(|p| p.crate_path())
+    }
+}
 
-    let mut dir = &*cd;
-    loop {
-        let toml = dir.join("Cargo.toml");
+#[derive(Debug, Deserialize)]
+pub struct Package {
+    id: String,
+    manifest_path: PathBuf,
+    source: Option<String>,
+}
 
-        if fs::metadata(&toml).is_ok() {
-            return Ok(Some(Root {
-                path: dir.to_owned(),
-            }));
+impl Package {
+    /// Returns the absolute path to the packages manifest "folder"
+    fn crate_path(&self) -> Option<&Path> {
+        // when source is none, this package is a path dependency or a workspace member
+        if self.source.is_none() {
+            self.manifest_path.parent()
+        } else {
+            None
         }
+    }
+}
 
-        match dir.parent() {
-            Some(p) => dir = p,
-            None => break,
+/// Cargo metadata with specific invocation
+pub fn cargo_metadata_with_args(
+    cd: Option<&Path>,
+    args: Option<&Args>,
+    verbose: bool,
+) -> Result<Option<CargoMetadata>> {
+    let mut command = std::process::Command::new(
+        std::env::var("CARGO")
+            .ok()
+            .unwrap_or_else(|| "cargo".to_string()),
+    );
+    command.arg("metadata").arg("--format-version=1");
+    if let Some(cd) = cd {
+        command.current_dir(cd);
+    }
+    if let Some(config) = args {
+        if let Some(ref manifest_path) = config.manifest_path {
+            command.args(["--manifest-path".as_ref(), manifest_path.as_os_str()]);
         }
+    } else {
+        command.arg("--no-deps");
     }
-
-    Ok(None)
+    if let Some(target) = args.and_then(|a| a.target.as_ref()) {
+        command.args(["--filter-platform", target.triple()]);
+    }
+    if let Some(features) = args.map(|a| &a.features).filter(|v| !v.is_empty()) {
+        command.args([String::from("--features"), features.join(",")]);
+    }
+    let output = command.run_and_get_output(verbose)?;
+    if !output.status.success() {
+        // TODO: logging
+        return Ok(None);
+    }
+    let manifest: Option<CargoMetadata> = serde_json::from_slice(&output.stdout)?;
+    manifest
+        .map(|m| -> Result<_> {
+            Ok(CargoMetadata {
+                target_directory: args
+                    .and_then(|a| a.target_dir.clone())
+                    .unwrap_or(m.target_directory),
+                ..m
+            })
+        })
+        .transpose()
 }
 
 /// Pass-through mode

src/cli.rs

@@ -12,9 +12,11 @@ pub struct Args {
     pub subcommand: Option<Subcommand>,
     pub channel: Option<String>,
     pub target: Option<Target>,
+    pub features: Vec<String>,
     pub target_dir: Option<PathBuf>,
     pub docker_in_docker: bool,
     pub enable_doctests: bool,
+    pub manifest_path: Option<PathBuf>,
 }
 
 // Fix for issue #581. target_dir must be absolute.
@@ -72,6 +74,8 @@ pub fn fmt_subcommands(stdout: &str) {
 pub fn parse(target_list: &TargetList) -> Result<Args> {
     let mut channel = None;
     let mut target = None;
+    let mut features = Vec::new();
+    let mut manifest_path: Option<PathBuf> = None;
     let mut target_dir = None;
     let mut sc = None;
     let mut all: Vec<String> = Vec::new();
@@ -82,7 +86,21 @@ pub fn parse(target_list: &TargetList) -> Result<Args> {
             if arg.is_empty() {
                 continue;
             }
-            if let ("+", ch) = arg.split_at(1) {
+            if arg == "--manifest-path" {
+                all.push(arg);
+                if let Some(m) = args.next() {
+                    let p = PathBuf::from(&m);
+                    all.push(m);
+                    manifest_path = env::current_dir().ok().map(|cwd| cwd.join(p));
+                }
+            } else if arg.starts_with("--manifest-path=") {
+                manifest_path = arg
+                    .split_once('=')
+                    .map(|x| x.1)
+                    .map(PathBuf::from)
+                    .and_then(|p| env::current_dir().ok().map(|cwd| cwd.join(p)));
+                all.push(arg);
+            } else if let ("+", ch) = arg.split_at(1) {
                 channel = Some(ch.to_string());
             } else if arg == "--target" {
                 all.push(arg);
@@ -95,6 +113,15 @@ pub fn parse(target_list: &TargetList) -> Result<Args> {
                     .split_once('=')
                     .map(|(_, t)| Target::from(t, target_list));
                 all.push(arg);
+            } else if arg == "--features" {
+                all.push(arg);
+                if let Some(t) = args.next() {
+                    features.push(t.clone());
+                    all.push(t);
+                }
+            } else if arg.starts_with("--features=") {
+                features.extend(arg.split_once('=').map(|(_, t)| t.to_owned()));
+                all.push(arg);
             } else if arg == "--target-dir" {
                 all.push(arg);
                 if let Some(td) = args.next() {
@@ -128,8 +155,10 @@ pub fn parse(target_list: &TargetList) -> Result<Args> {
         subcommand: sc,
         channel,
         target,
+        features,
         target_dir,
         docker_in_docker,
         enable_doctests,
+        manifest_path,
     })
 }