rustc: add support for alwayslink library dependencies

This follows up on the previous commit's refactoring and actually adds alwayslink support. Fixes #325.
bazelbuild · Feb 25, 2021 · 12bcb7c · 12bcb7c
1 parent ec127db
commit 12bcb7c
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Showing 2 changed files with 39 additions and 5 deletions.
diff --git a/rust/private/rustc.bzl b/rust/private/rustc.bzl
@@ -821,7 +821,22 @@ def _make_link_flags(toolchain, lib):
     args = []
     f = get_preferred_artifact(lib)
     if lib.alwayslink:
-        pass  # TODO
+        if toolchain.os.startswith("darwin") or toolchain.os.startswith("macos"):
+            args.extend([
+                "-C",
+                ("link-arg=-Wl,-force_load,%s" % f.path),
+            ])
+        elif toolchain.os.startswith("win"):
+            args.append("/WHOLEARCHIVE:%s" % f.path)
+        else:
+            args.extend([
+                "-C",
+                "link-arg=-Wl,--whole-archive",
+                "-C",
+                ("link-arg=%s" % f.path),
+                "-C",
+                "link-arg=-Wl,--no-whole-archive",
+            ])
     elif lib.static_library or lib.pic_static_library:
         args.append("-lstatic=%s" % get_lib_name(f))
     elif _is_dylib(toolchain, lib):

diff --git a/test/unit/native_deps/native_deps_test.bzl b/test/unit/native_deps/native_deps_test.bzl
@@ -104,24 +104,43 @@ def _bin_has_native_libs_test_impl(ctx):
     return analysistest.end(env)
 
 def _extract_linker_args(argv):
-    return [a for a in argv if a.startswith("link-arg=-Wl") or a.startswith("link-arg=-l") or a.startswith("-l")]
+    return [a for a in argv if a.startswith("link-arg=-Wl") or a.startswith("link-arg=-l") or a.startswith("-l") or a.endswith(".lo") or a.endswith(".o")]
 
 def _bin_has_native_dep_and_alwayslink_test_impl(ctx):
     env = analysistest.begin(ctx)
     tut = analysistest.target_under_test(env)
     actions = analysistest.target_actions(env)
     action = actions[0]
 
-    # BUG: this should mention the alwayslink library, but doesn't
-    asserts.equals(env, _extract_linker_args(action.argv), ["-lstatic=native_dep"])
+    if ctx.target_platform_has_constraint(ctx.attr._macos_constraint[platform_common.ConstraintValueInfo]):
+        want = [
+            "-lstatic=native_dep",
+            "link-arg=-Wl,-force_load,bazel-out/darwin-fastbuild/bin/test/unit/native_deps/libalwayslink.lo",
+        ]
+    elif ctx.target_platform_has_constraint(ctx.attr._windows_constraint[platform_common.ConstraintValueInfo]):
+        want = [
+            "-lstatic=native_dep",
+            "/WHOLEARCHIVE:bazel-out/darwin-fastbuild/bin/test/unit/native_deps/libalwayslink.lo",
+        ]
+    else:
+        want = [
+            "-lstatic=native_dep",
+            "link-arg=-Wl,--whole-archive",
+            "link-arg=bazel-out/k8-fastbuild/bin/test/unit/native_deps/libalwayslink.lo",
+            "link-arg=-Wl,--no-whole-archive",
+        ]
+    asserts.equals(env, _extract_linker_args(action.argv), want)
     return analysistest.end(env)
 
 rlib_has_no_native_libs_test = analysistest.make(_rlib_has_no_native_libs_test_impl)
 staticlib_has_native_libs_test = analysistest.make(_staticlib_has_native_libs_test_impl)
 cdylib_has_native_libs_test = analysistest.make(_cdylib_has_native_libs_test_impl)
 proc_macro_has_native_libs_test = analysistest.make(_proc_macro_has_native_libs_test_impl)
 bin_has_native_libs_test = analysistest.make(_bin_has_native_libs_test_impl)
-bin_has_native_dep_and_alwayslink_test = analysistest.make(_bin_has_native_dep_and_alwayslink_test_impl)
+bin_has_native_dep_and_alwayslink_test = analysistest.make(_bin_has_native_dep_and_alwayslink_test_impl, attrs = {
+    "_macos_constraint": attr.label(default = Label("@platforms//os:macos")),
+    "_windows_constraint": attr.label(default = Label("@platforms//os:windows")),
+})
 
 def _native_dep_test():
     rust_library(