Add support for Cargo workspace inheritance

https://doc.rust-lang.org/cargo/reference/specifying-dependencies.html#inheriting-a-dependency-from-a-workspace

Changelog.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Fix `Cargo.toml` in new project template in [#1109](https://github.com/PyO3/maturin/pull/1109)
 * Fix `maturin develop` on Windows when using Python installed from msys2 in [#1112](https://github.com/PyO3/maturin/pull/1112)
 * Fix duplicated `Cargo.toml` of local dependencies in sdist in [#1114](https://github.com/PyO3/maturin/pull/1114)
+* Add support for Cargo workspace inheritance in [#1123](https://github.com/PyO3/maturin/pull/1123)
 
 ## [0.13.3] - 2022-09-15
 

src/source_distribution.rs

@@ -41,17 +41,28 @@ fn rewrite_cargo_toml(
         if let Some(table) = data.get_mut(*dep_category).and_then(|x| x.as_table_mut()) {
             let dep_names: Vec<_> = table.iter().map(|(key, _)| key.to_string()).collect();
             for dep_name in dep_names {
-                // There should either be no value for path, or it should be a string
-                if table.get(&dep_name).and_then(|x| x.get("path")).is_none() {
-                    continue;
+                let mut workspace_inherit = false;
+                if let Some(true) = table
+                    .get(&dep_name)
+                    .and_then(|x| x.get("workspace"))
+                    .and_then(|x| x.as_bool())
+                {
+                    workspace_inherit = true;
                 }
-                if !table[&dep_name]["path"].is_str() {
-                    bail!(
-                        "In {}, {} {} has a path value that is not a string",
-                        manifest_path.as_ref().display(),
-                        dep_category,
-                        dep_name
-                    )
+
+                if !workspace_inherit {
+                    // There should either be no value for path, or it should be a string
+                    if table.get(&dep_name).and_then(|x| x.get("path")).is_none() {
+                        continue;
+                    }
+                    if !table[&dep_name]["path"].is_str() {
+                        bail!(
+                            "In {}, {} {} has a path value that is not a string",
+                            manifest_path.as_ref().display(),
+                            dep_category,
+                            dep_name
+                        )
+                    }
                 }
                 if !known_path_deps.contains_key(&dep_name) {
                     bail!(
@@ -69,6 +80,10 @@ fn rewrite_cargo_toml(
                     // Cargo.toml contains relative paths, and we're already in LOCAL_DEPENDENCIES_FOLDER
                     toml_edit::value(format!("../{}", dep_name))
                 };
+                if workspace_inherit {
+                    // Remove workspace inheritance now that we converted it into a path dependency
+                    table[&dep_name].as_table_mut().unwrap().remove("workspace");
+                }
                 rewritten = true;
             }
         }

test-crates/workspace-inheritance/Cargo.toml

@@ -0,0 +1,8 @@
+[workspace]
+members = [
+  "generic_lib",
+  "python"
+]
+
+[workspace.dependencies]
+generic_lib = { path = "generic_lib" }

test-crates/workspace-inheritance/generic_lib/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "generic_lib"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

test-crates/workspace-inheritance/generic_lib/src/lib.rs

@@ -0,0 +1,3 @@
+pub fn foo() -> &'static str {
+    "foo"
+}

test-crates/workspace-inheritance/python/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "workspace-inheritance"
+version = "0.1.0"
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[lib]
+name = "workspace_inheritance"
+crate-type = ["cdylib"]
+
+[dependencies]
+pyo3 = { version = "0.16.5", features = ["extension-module"] }
+generic_lib.workspace = true

test-crates/workspace-inheritance/python/pyproject.toml

@@ -0,0 +1,3 @@
+[build-system]
+requires = ["maturin>=0.13,<0.14"]
+build-backend = "maturin"

test-crates/workspace-inheritance/python/src/lib.rs

@@ -0,0 +1,14 @@
+use pyo3::prelude::*;
+
+/// Formats the sum of two numbers as string.
+#[pyfunction]
+fn sum_as_string(a: usize, b: usize) -> PyResult<String> {
+    Ok((a + b).to_string())
+}
+
+/// A Python module implemented in Rust.
+#[pymodule]
+fn workspace_with_path_dep(_py: Python, m: &PyModule) -> PyResult<()> {
+    m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
+    Ok(())
+}

tests/run.rs

@@ -293,6 +293,22 @@ fn workspace_with_path_dep_sdist() {
     ))
 }
 
+#[test]
+fn workspace_inheritance_sdist() {
+    handle_result(other::test_source_distribution(
+        "test-crates/workspace-inheritance/python",
+        vec![
+            "workspace_inheritance-0.1.0/local_dependencies/generic_lib/Cargo.toml",
+            "workspace_inheritance-0.1.0/local_dependencies/generic_lib/src/lib.rs",
+            "workspace_inheritance-0.1.0/Cargo.toml",
+            "workspace_inheritance-0.1.0/pyproject.toml",
+            "workspace_inheritance-0.1.0/src/lib.rs",
+            "workspace_inheritance-0.1.0/PKG-INFO",
+        ],
+        "workspace_inheritance_sdist",
+    ))
+}
+
 #[test]
 fn abi3_python_interpreter_args() {
     handle_result(other::abi3_python_interpreter_args());