Alias workspace members from crate hubs

Author: dzbarsky

rs/extensions.bzl

@@ -15,6 +15,7 @@ load(
     "split_lockfile_packages",
     "workspace_dep_data",
     _fq_crate = "fq_crate",
+    _manifest_package_dir = "manifest_package_dir",
     _normalize_path = "normalize_path",
     _select = "select_items",
 )
@@ -416,6 +417,12 @@ crate.annotation(
         _fq_crate(package["name"], package["version"]): package
         for package in packages
     }
+    workspace_member_by_fq = {
+        _fq_crate(package["name"], package["version"]): package
+        for package in cargo_metadata["packages"]
+    }
+    repo_root = _normalize_path(cargo_metadata["workspace_root"])
+    workspace_package = _label_directory(cargo_lock_path)
 
     hub_contents = []
     for name, versions in versions_by_name.items():
@@ -478,6 +485,35 @@ alias(
                     default_version = default_version,
                 ))
 
+    workspace_member_hub_aliases = {}
+    hub_label_prefix = "@%s//:" % hub_name
+    for package in packages:
+        feature_resolutions = package["feature_resolutions"]
+        for deps_by_triple in [feature_resolutions.deps, feature_resolutions.build_deps]:
+            for deps in deps_by_triple.values():
+                for bazel_target in deps:
+                    if not bazel_target.startswith(hub_label_prefix):
+                        continue
+
+                    fq = bazel_target.removeprefix(hub_label_prefix)
+                    workspace_member = workspace_member_by_fq.get(fq)
+                    if workspace_member:
+                        workspace_member_hub_aliases[fq] = workspace_member
+
+    for fq in sorted(workspace_member_hub_aliases.keys()):
+        package = workspace_member_hub_aliases[fq]
+        package_dir = _manifest_package_dir(package["manifest_path"], repo_root)
+        bazel_package = paths.join(workspace_package, package_dir).removesuffix("/")
+        hub_contents.append("""
+alias(
+    name = "{name}-{version}",
+    actual = "@@//{bazel_package}",
+)""".format(
+            name = package["name"],
+            version = package["version"],
+            bazel_package = bazel_package,
+        ))
+
     workspace_deps, conditional_workspace_deps = render_select(
         [],
         workspace_dep_labels_by_triple,
@@ -577,8 +613,6 @@ RESOLVED_PLATFORMS = select({{
 
     _date(mctx, "done")
 
-    repo_root = _normalize_path(cargo_metadata["workspace_root"])
-    workspace_package = _label_directory(cargo_lock_path)
     data_bzl_contents = render_dep_data(workspace_dep_data(
         cargo_metadata = cargo_metadata,
         feature_resolutions_by_fq_crate = feature_resolutions_by_fq_crate,

test/BUILD.bazel

@@ -171,6 +171,23 @@ genquery(
     scope = ["@workspace_member_annotation_features//:dep_leaf-0.1.0"],
 )
 
+genquery(
+    name = "vendored_workspace_dep_itoa_deps",
+    expression = "deps(@vendored_workspace_dep//:itoa-1.0.11)",
+    scope = ["@vendored_workspace_dep//:itoa-1.0.11"],
+)
+
+genrule(
+    name = "verify_vendored_workspace_dep",
+    srcs = [":vendored_workspace_dep_itoa_deps"],
+    outs = ["verify_vendored_workspace_dep.txt"],
+    cmd = """
+        grep 'vendored_workspace_dep//:mylib-0.1.0' $(location :vendored_workspace_dep_itoa_deps)
+        grep '//vendored_workspace_dep/mylib:mylib' $(location :vendored_workspace_dep_itoa_deps)
+        echo ok > $@
+    """,
+)
+
 verify_alias(
     name = "verify_workspace_hyphen_dep_aliases",
     aliases = workspace_hyphen_dep_aliases_aliases(package_name = "workspace_hyphen_dep_aliases/consumer"),
@@ -305,6 +322,7 @@ filegroup(
         ":verify_workspace_default_features_subfeature_present",
         ":verify_workspace_hyphen_dep_aliases",
         ":verify_workspace_member_annotation_features",
+        ":verify_vendored_workspace_dep",
         ":verify_workspace_renamed_path_dep_aliases",
         "//prost:echo_rust_proto",
         "//self_dev_dependency/mycrate",

test/MODULE.bazel

@@ -148,6 +148,7 @@ TESTS = [
     "target_workspace_dep_feature",
     "vendored_crate_override",
     "workspace_default_features",
+    "vendored_workspace_dep",
     "workspace_member_annotation_features",
     "workspace_git_dep",
     "workspace_path_dependency",

test/MODULE.bazel.lock

@@ -0,0 +1 @@
+package(default_visibility = ["//visibility:public"])

test/vendored_workspace_dep/BUILD.bazel

@@ -0,0 +1,8 @@
+[workspace]
+members = ["mylib", "app"]
+exclude = ["vendor/itoa"]
+resolver = "3"
+
+[workspace.dependencies]
+mylib = { path = "./mylib" }
+itoa = { path = "./vendor/itoa" }

test/vendored_workspace_dep/Cargo.lock

@@ -0,0 +1,7 @@
+[package]
+name = "vendored_workspace_dep_demo"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+itoa = { workspace = true }

test/vendored_workspace_dep/Cargo.toml

@@ -0,0 +1,5 @@
+fn main() {
+    let mut buffer = itoa::Buffer::new();
+    let formatted = buffer.format(42);
+    println!("vendored itoa says: {formatted}");
+}

test/vendored_workspace_dep/app/Cargo.toml

@@ -0,0 +1,9 @@
+load("@rules_rs//rs:rust_library.bzl", "rust_library")
+
+package(default_visibility = ["//visibility:public"])
+
+rust_library(
+    name = "mylib",
+    srcs = ["src/lib.rs"],
+    edition = "2024",
+)