feat(third_party/bazel): Check in rules_haskell from Tweag

third_party/bazel/rules_haskell/debug/linking_utils/BUILD.bazel

@@ -0,0 +1,50 @@
+load(
+    ":ldd_test.bzl",
+    "ldd_test",
+)
+
+py_library(
+    name = "linking_utils",
+    srcs = ["ldd.py"],
+    visibility = ["//visibility:public"],
+)
+
+# test the ldd debug library on the output of `//tests/binary-indirect-cbits`
+ldd_test(
+    name = "test-ldd",
+    current_workspace = None,
+    elf_binary = "//tests/binary-indirect-cbits",
+    script = r'''
+import sys
+
+def contains_error(error):
+    """check whether any of the dependencies contains `error`,
+    where error is something from `LDD_ERRORS`.
+    Returns {} if there's no error.
+    """
+    def f(d):
+        return { k: v for k, v in d['needed'].items()
+          if (v == error
+             or (v not in LDD_ERRORS
+                and dict_remove_empty(v['item']) != {})) }
+    return f
+
+# output should have some runpaths
+assert \
+    ldd(identity, sys.argv[1])['runpath_dirs']\
+    > 0
+
+# some of the dependencies are implicit and not in NEEDED flags
+assert ldd(contains_error(LDD_UNKNOWN), sys.argv[1])
+
+import pprint
+# none of the dependencies must be missing
+res = ldd(contains_error(LDD_MISSING), sys.argv[1])
+if res != {}:
+  print("These dependencies are missing:")
+  pprint.pprint(res)
+  exit(1)
+''',
+    # it only works on linux
+    tags = ["dont_test_on_darwin"],
+)