create symlinks to ambiguous native dependencies (#1148)

Co-authored-by: cfredric <cfredric@chromium.org>
Co-authored-by: Chris Fredrickson <cfredric@users.noreply.github.com>

examples/ambiguous_deps/BUILD.bazel

@@ -0,0 +1,40 @@
+load("@rules_cc//cc:defs.bzl", "cc_library")
+load("@rules_rust//rust:defs.bzl", "rust_binary")
+
+# A rust_binary that depends on two native libs with the same name.
+# See https://github.com/bazelbuild/rules_rust/issues/840.
+rust_binary(
+    name = "bin_with_same_name_deps",
+    srcs = ["bin.rs"],
+    deps = [
+        "//ambiguous_deps/x:exc",
+        "//ambiguous_deps/y:exc",
+    ],
+)
+
+# A rust_binary that depends on a native library with a name that doesn't
+# match the `lib<name>.a` pattern on linux.
+rust_binary(
+    name = "nonstandard_name_bin",
+    srcs = ["nonstandard_name_bin.rs"],
+    deps = [":nonstandard_name_intermediate"],
+)
+
+cc_library(
+    name = "nonstandard_name_cc_lib",
+    srcs = ["cc_library_with_func.cc"],
+)
+
+genrule(
+    name = "nonstandard_name_gen",
+    srcs = [":nonstandard_name_cc_lib"],
+    outs = ["nonstandard_name_gen.a"],
+    # Copy the first member (libnonstandard_name_cc_lib.a) from the srcs to the
+    # output nonstandard_name_gen.a.
+    cmd = "cp $$(awk '{print $$1}' <<< '$(SRCS)') $@",
+)
+
+cc_library(
+    name = "nonstandard_name_intermediate",
+    srcs = [":nonstandard_name_gen.a"],
+)

examples/ambiguous_deps/bin.rs

@@ -0,0 +1,10 @@
+use std::os::raw::c_int;
+
+extern "C" {
+    pub fn cx() -> c_int;
+    pub fn cy() -> c_int;
+}
+
+fn main() {
+    println!("hi {} {}", unsafe { cx() }, unsafe { cy() });
+}

examples/ambiguous_deps/cc_library_with_func.cc

@@ -0,0 +1,3 @@
+extern "C" int func() {
+  return 123;
+}

examples/ambiguous_deps/nonstandard_name_bin.rs

@@ -0,0 +1,9 @@
+use std::os::raw::c_int;
+
+extern "C" {
+    pub fn func() -> c_int;
+}
+
+fn main() {
+    println!("hi {}", unsafe { func() });
+}

examples/ambiguous_deps/x/BUILD.bazel

@@ -0,0 +1,7 @@
+load("@rules_cc//cc:defs.bzl", "cc_library")
+
+cc_library(
+    name = "exc",
+    srcs = ["exc.cc"],
+    visibility = ["//ambiguous_deps:__subpackages__"],
+)

examples/ambiguous_deps/x/exc.cc

@@ -0,0 +1 @@
+extern "C" int cx() { return 17; }

examples/ambiguous_deps/y/BUILD.bazel

@@ -0,0 +1,7 @@
+load("@rules_cc//cc:defs.bzl", "cc_library")
+
+cc_library(
+    name = "exc",
+    srcs = ["exc.cc"],
+    visibility = ["//ambiguous_deps:__subpackages__"],
+)

examples/ambiguous_deps/y/exc.cc

@@ -0,0 +1 @@
+extern "C" int cy() { return 113; }

rust/private/clippy.bzl

@@ -70,7 +70,7 @@ def _clippy_aspect_impl(target, ctx):
         are_linkstamps_supported = False,
     )
 
-    compile_inputs, out_dir, build_env_files, build_flags_files, linkstamp_outs = collect_inputs(
+    compile_inputs, out_dir, build_env_files, build_flags_files, linkstamp_outs, ambiguous_libs = collect_inputs(
         ctx,
         ctx.rule.file,
         ctx.rule.files,
@@ -94,6 +94,7 @@ def _clippy_aspect_impl(target, ctx):
         crate_info = crate_info,
         dep_info = dep_info,
         linkstamp_outs = linkstamp_outs,
+        ambiguous_libs = ambiguous_libs,
         output_hash = determine_output_hash(crate_info.root, ctx.label),
         rust_flags = [],
         out_dir = out_dir,