Merge branch 'main' into data

cargo/cargo_build_script.bzl

@@ -8,7 +8,7 @@ load("//rust:rust.bzl", "rust_binary")
 load("//rust/private:rustc.bzl", "BuildInfo", "get_compilation_mode_opts", "get_linker_and_args")
 
 # buildifier: disable=bzl-visibility
-load("//rust/private:utils.bzl", "expand_locations", "find_cc_toolchain", "find_toolchain", "name_to_crate_name")
+load("//rust/private:utils.bzl", "expand_dict_value_locations", "find_cc_toolchain", "find_toolchain", "name_to_crate_name")
 
 def get_cc_compile_env(cc_toolchain, feature_configuration):
     """Gather cc environment variables from the given `cc_toolchain`
@@ -117,7 +117,7 @@ def _build_script_impl(ctx):
     for f in ctx.attr.crate_features:
         env["CARGO_FEATURE_" + f.upper().replace("-", "_")] = "1"
 
-    env.update(expand_locations(
+    env.update(expand_dict_value_locations(
         ctx,
         ctx.attr.build_script_env,
         getattr(ctx.attr, "data", []) +

docs/BUILD.bazel

@@ -113,6 +113,7 @@ PAGES = dict([
             "rust_toolchain",
             "rust_toolchain_repository",
             "rust_toolchain_repository_proxy",
+            "rust_stdlib_filegroup",
         ],
     ),
     page(

docs/rust_repositories.md

@@ -6,6 +6,26 @@
 * [rust_toolchain](#rust_toolchain)
 * [rust_toolchain_repository](#rust_toolchain_repository)
 * [rust_toolchain_repository_proxy](#rust_toolchain_repository_proxy)
+* [rust_stdlib_filegroup](#rust_stdlib_filegroup)
+
+<a id="#rust_stdlib_filegroup"></a>
+
+## rust_stdlib_filegroup
+
+<pre>
+rust_stdlib_filegroup(<a href="#rust_stdlib_filegroup-name">name</a>, <a href="#rust_stdlib_filegroup-srcs">srcs</a>)
+</pre>
+
+A dedicated filegroup-like rule for Rust stdlib artifacts.
+
+**ATTRIBUTES**
+
+
+| Name  | Description | Type | Mandatory | Default |
+| :------------- | :------------- | :------------- | :------------- | :------------- |
+| <a id="rust_stdlib_filegroup-name"></a>name |  A unique name for this target.   | <a href="https://bazel.build/docs/build-ref.html#name">Name</a> | required |  |
+| <a id="rust_stdlib_filegroup-srcs"></a>srcs |  The list of targets/files that are components of the rust-stdlib file group   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | required |  |
+
 
 <a id="#rust_toolchain"></a>
 

docs/symbols.bzl

@@ -62,6 +62,7 @@ load(
 )
 load(
     "@rules_rust//rust:toolchain.bzl",
+    _rust_stdlib_filegroup = "rust_stdlib_filegroup",
     _rust_toolchain = "rust_toolchain",
 )
 load(
@@ -96,6 +97,7 @@ rust_bindgen_repositories = _rust_bindgen_repositories
 rust_toolchain = _rust_toolchain
 rust_proto_toolchain = _rust_proto_toolchain
 rust_proto_repositories = _rust_proto_repositories
+rust_stdlib_filegroup = _rust_stdlib_filegroup
 
 cargo_build_script = _cargo_build_script
 

examples/flag_locations/BUILD.bazel

@@ -0,0 +1,23 @@
+load(
+    "@rules_rust//rust:rust.bzl",
+    "rust_test",
+)
+
+# generate a file containing cfg flags
+genrule(
+    name = "flag_generator",
+    outs = ["generated_flag.data"],
+    cmd = "echo --cfg=test_flag > $@",
+)
+
+rust_test(
+    name = "test",
+    srcs = [
+        "main.rs",
+    ],
+    data = [":flag_generator"],
+    edition = "2018",
+    rustc_flags = [
+        "@$(location :flag_generator)",
+    ],
+)

examples/flag_locations/main.rs

@@ -0,0 +1,9 @@
+#[test]
+fn test() {
+    // we should be able to read rustc args from a generated file
+    if cfg!(test_flag) {
+        return;
+    }
+
+    unreachable!();
+}

rust/defs.bzl

@@ -14,6 +14,10 @@
 
 """Public entry point to all Rust rules and supported APIs."""
 
+load(
+    "//rust:toolchain.bzl",
+    _rust_stdlib_filegroup = "rust_stdlib_filegroup",
+)
 load(
     "//rust/private:clippy.bzl",
     _rust_clippy = "rust_clippy",
@@ -111,3 +115,6 @@ rustfmt_aspect = _rustfmt_aspect
 
 rustfmt_test = _rustfmt_test
 # See @rules_rust//rust/private:rustfmt.bzl for a complete description.
+
+rust_stdlib_filegroup = _rust_stdlib_filegroup
+# See @rules_rust//rust:toolchain.bzl for a complete description.

rust/private/common.bzl

@@ -23,7 +23,7 @@ which exports the `rust_common` struct.
 In the Bazel lingo, `rust_common` gives the access to the Rust Sandwich API.
 """
 
-load(":providers.bzl", "CrateInfo", "DepInfo")
+load(":providers.bzl", "CrateInfo", "DepInfo", "StdLibInfo")
 
 def _create_crate_info(**kwargs):
     """A constructor for a `CrateInfo` provider
@@ -43,4 +43,5 @@ rust_common = struct(
     create_crate_info = _create_crate_info,
     crate_info = CrateInfo,
     dep_info = DepInfo,
+    stdlib_info = StdLibInfo,
 )

rust/private/providers.bzl

@@ -43,3 +43,20 @@ DepInfo = provider(
         "transitive_noncrates": "depset[LinkerInput]: All transitive dependencies that aren't crates.",
     },
 )
+
+StdLibInfo = provider(
+    doc = (
+        "A collection of files either found within the `rust-stdlib` artifact or " +
+        "generated based on existing files."
+    ),
+    fields = {
+        "alloc_files": "List[File]: `.a` files related to the `alloc` module.",
+        "between_alloc_and_core_files": "List[File]: `.a` files related to the `compiler_builtins` module.",
+        "between_core_and_std_files": "List[File]: `.a` files related to all modules except `adler`, `alloc`, `compiler_builtins`, `core`, and `std`.",
+        "core_files": "List[File]: `.a` files related to the `core` and `adler` modules",
+        "dot_a_files": "Depset[File]: Generated `.a` files",
+        "srcs": "List[Target]: The original `src` attribute.",
+        "std_files": "Depset[File]: `.a` files associated with the `std` module.",
+        "std_rlibs": "List[File]: All `.rlib` files",
+    },
+)

rust/private/repository_utils.bzl

@@ -138,7 +138,9 @@ def BUILD_for_clippy(target_triple):
     return _build_file_for_clippy_template.format(binary_ext = system_to_binary_ext(system))
 
 _build_file_for_stdlib_template = """\
-filegroup(
+load("@rules_rust//rust:toolchain.bzl", "rust_stdlib_filegroup")
+
+rust_stdlib_filegroup(
     name = "rust_lib-{target_triple}",
     srcs = glob(
         [

rust/private/rust.bzl

@@ -20,7 +20,7 @@ load(
     "crate_name_from_attr",
     "dedent",
     "determine_output_hash",
-    "expand_locations",
+    "expand_dict_value_locations",
     "find_toolchain",
 )
 
@@ -342,7 +342,7 @@ def _create_test_launcher(ctx, toolchain, output, providers):
 
     # Expand the environment variables and write them to a file
     environ_file = ctx.actions.declare_file(launcher_filename + ".launchfiles/env")
-    environ = expand_locations(
+    environ = expand_dict_value_locations(
         ctx,
         getattr(ctx.attr, "env", {}),
         data,
@@ -624,7 +624,14 @@ _common_attrs = {
         """),
     ),
     "rustc_flags": attr.string_list(
-        doc = "List of compiler flags passed to `rustc`.",
+        doc = dedent("""\
+            List of compiler flags passed to `rustc`.
+
+            These strings are subject to Make variable expansion for predefined
+            source/output path variables like `$location`, `$execpath`, and `$rootpath`.
+            This expansion is useful if you wish to pass a generated file of
+            arguments to rustc: `@$(location //package:target)`.
+        """),
     ),
     # TODO(stardoc): How do we provide additional documentation to an inherited attribute?
     # "name": attr.string(

rust/private/rustc.bzl

@@ -21,7 +21,8 @@ load("//rust/private:common.bzl", "rust_common")
 load(
     "//rust/private:utils.bzl",
     "crate_name_from_attr",
-    "expand_locations",
+    "expand_dict_value_locations",
+    "expand_list_element_locations",
     "find_cc_toolchain",
     "get_lib_name",
     "get_preferred_artifact",
@@ -438,9 +439,16 @@ def construct_arguments(
 
     # Tell Rustc where to find the standard library
     args.add_all(rust_lib_paths, before_each = "-L", format_each = "%s")
-
     args.add_all(rust_flags)
-    args.add_all(getattr(attr, "rustc_flags", []))
+
+    data_paths = getattr(attr, "data", []) + getattr(attr, "compile_data", [])
+    args.add_all(
+        expand_list_element_locations(
+            ctx,
+            getattr(attr, "rustc_flags", []),
+            data_paths,
+        ),
+    )
     add_edition_flags(args, crate_info)
 
     # Link!
@@ -471,11 +479,10 @@ def construct_arguments(
                 env["CARGO_BIN_EXE_" + dep_crate_info.output.basename] = dep_crate_info.output.short_path
 
     # Update environment with user provided variables.
-    env.update(expand_locations(
+    env.update(expand_dict_value_locations(
         ctx,
         crate_info.rustc_env,
-        getattr(attr, "data", []) +
-        getattr(attr, "compile_data", []),
+        data_paths,
     ))
 
     # This empty value satisfies Clippy, which otherwise complains about the

rust/private/utils.bzl

@@ -152,7 +152,7 @@ def _expand_location(ctx, env, data):
             env = env.replace(directive, "${pwd}/" + directive)
     return ctx.expand_location(env, data)
 
-def expand_locations(ctx, env, data):
+def expand_dict_value_locations(ctx, env, data):
     """Performs location-macro expansion on string values.
 
     $(execroot ...) and $(location ...) are prefixed with ${pwd},
@@ -167,6 +167,8 @@ def expand_locations(ctx, env, data):
     as compilation happens in a separate sandbox folder, so when it comes time
     to read the file at runtime, the path is no longer valid.
 
+    See [`expand_location`](https://docs.bazel.build/versions/main/skylark/lib/ctx.html#expand_location) for detailed documentation.
+
     Args:
         ctx (ctx): The rule's context object
         env (dict): A dict whose values we iterate over
@@ -179,6 +181,27 @@ def expand_locations(ctx, env, data):
     """
     return dict([(k, _expand_location(ctx, v, data)) for (k, v) in env.items()])
 
+def expand_list_element_locations(ctx, args, data):
+    """Performs location-macro expansion on a list of string values.
+
+    $(execroot ...) and $(location ...) are prefixed with ${pwd},
+    which process_wrapper and build_script_runner will expand at run time
+    to the absolute path.
+
+    See [`expand_location`](https://docs.bazel.build/versions/main/skylark/lib/ctx.html#expand_location) for detailed documentation.
+
+    Args:
+        ctx (ctx): The rule's context object
+        args (list): A list we iterate over
+        data (sequence of Targets): The targets which may be referenced by
+            location macros. This is expected to be the `data` attribute of
+            the target, though may have other targets or attributes mixed in.
+
+    Returns:
+        list: A list of arguments with expanded location macros
+    """
+    return [_expand_location(ctx, arg, data) for arg in args]
+
 def name_to_crate_name(name):
     """Converts a build target's name into the name of its associated crate.