test

Author: UebelAndre

rust/private/rustdoc_test.bzl

@@ -14,6 +14,7 @@
 
 # buildifier: disable=module-docstring
 load("//rust/private:common.bzl", "rust_common")
+load("//rust/private:toolchain_utils.bzl", "find_sysroot")
 load("//rust/private:utils.bzl", "find_toolchain", "get_lib_name", "get_preferred_artifact")
 load("//util/launcher:launcher.bzl", "create_launcher")
 
@@ -114,6 +115,10 @@ def _build_rustdoc_flags(dep_info, crate_info, toolchain):
     link_flags += ["--extern=" + c.name + "=" + c.dep.output.short_path for c in d.direct_crates.to_list()]
     link_search_flags += ["-Ldependency={}".format(_dirname(c.output.short_path)) for c in d.transitive_crates.to_list()]
 
+    sysroot = find_sysroot(toolchain, short_path = True)
+    if sysroot:
+        link_search_flags.extend(["--sysroot", "${{pwd}}/{}".format(sysroot)])
+
     # TODO(hlopko): use the more robust logic from rustc.bzl also here, through a reasonable API.
     for lib_to_link in dep_info.transitive_noncrates.to_list():
         is_static = bool(lib_to_link.static_library or lib_to_link.pic_static_library)

rust/private/toolchain_utils.bzl

@@ -1,5 +1,31 @@
 """A module defining toolchain utilities"""
 
+def find_sysroot(rust_toolchain, short_path = False):
+    """Locate the sysroot for a given toolchain
+
+    Args:
+        rust_toolchain (rust_toolchain): A rust toolchain
+        short_path (bool): Whether or not to use a short path to the sysroot
+
+    Returns:
+        str, optional: The path of the toolchain's sysroot
+    """
+
+    # Sysroot is determined by using a rust stdlib file, expected to be at
+    # `${SYSROOT}/lib/rustlib/${target_triple}/lib`, and strip the known
+    # directories from the sysroot path.
+    rust_stdlib_files = rust_toolchain.rust_lib.files.to_list()
+    if rust_stdlib_files:
+        # Determine the sysroot by taking a rust stdlib file, expected to be `${sysroot}/lib`
+        if short_path:
+            split = rust_stdlib_files[0].short_path.rsplit("/", 5)
+        else:
+            split = rust_stdlib_files[0].path.rsplit("/", 5)
+        sysroot = split[0]
+        return sysroot
+
+    return None
+
 def _toolchain_files_impl(ctx):
     toolchain = ctx.toolchains[str(Label("//rust:toolchain"))]
 

util/launcher/launcher_main.rs

@@ -75,10 +75,15 @@ fn args() -> Vec<String> {
     let args_path = std::env::args().next().expect("arg 0 was not set") + LAUNCHFILES_ARGS_PATH;
     let file = File::open(args_path).expect("Failed to load the environment file");
 
+    // Variables will have the `${pwd}` variable replaced which is rendered by
+    // `@rules_rust//rust/private:util.bzl::expand_dict_value_locations`
+    let pwd = std::env::current_dir().expect("Failed to get current working directory");
+    let pwd_str = pwd.to_string_lossy();
+
     // Note that arguments from the args file always go first
     BufReader::new(file)
         .lines()
-        .map(|line| line.expect("Failed to read file"))
+        .map(|line| line.expect("Failed to read file").replace("${pwd}", &pwd_str))
         .chain(std::env::args().skip(1))
         .collect()
 }