Add use_libtest_harness attribute to rust_test

docs/defs.md

@@ -466,7 +466,7 @@ When building the whole binary in Bazel, use `rust_library` instead.
 <pre>
 rust_test(<a href="#rust_test-name">name</a>, <a href="#rust_test-aliases">aliases</a>, <a href="#rust_test-compile_data">compile_data</a>, <a href="#rust_test-crate">crate</a>, <a href="#rust_test-crate_features">crate_features</a>, <a href="#rust_test-crate_name">crate_name</a>, <a href="#rust_test-crate_root">crate_root</a>, <a href="#rust_test-data">data</a>, <a href="#rust_test-deps">deps</a>,
           <a href="#rust_test-edition">edition</a>, <a href="#rust_test-env">env</a>, <a href="#rust_test-out_dir_tar">out_dir_tar</a>, <a href="#rust_test-proc_macro_deps">proc_macro_deps</a>, <a href="#rust_test-rustc_env">rustc_env</a>, <a href="#rust_test-rustc_env_files">rustc_env_files</a>, <a href="#rust_test-rustc_flags">rustc_flags</a>, <a href="#rust_test-srcs">srcs</a>,
-          <a href="#rust_test-version">version</a>)
+          <a href="#rust_test-use_libtest_harness">use_libtest_harness</a>, <a href="#rust_test-version">version</a>)
 </pre>
 
 Builds a Rust test crate.
@@ -619,6 +619,7 @@ Run the test with `bazel build //hello_lib:hello_lib_test`.
 | <a id="rust_test-rustc_env_files"></a>rustc_env_files |  Files containing additional environment variables to set for rustc.<br><br>These files should  contain a single variable per line, of format <code>NAME=value</code>, and newlines may be included in a value by ending a line with a trailing back-slash (<code>\</code>).<br><br>The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
 | <a id="rust_test-rustc_flags"></a>rustc_flags |  List of compiler flags passed to <code>rustc</code>.   | List of strings | optional | [] |
 | <a id="rust_test-srcs"></a>srcs |  List of Rust <code>.rs</code> source files used to build the library.<br><br>If <code>srcs</code> contains more than one file, then there must be a file either named <code>lib.rs</code>. Otherwise, <code>crate_root</code> must be set to the source file that is the root of the crate to be passed to rustc to build this crate.   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
+| <a id="rust_test-use_libtest_harness"></a>use_libtest_harness |  Whether to use libtest.   | Boolean | optional | True |
 | <a id="rust_test-version"></a>version |  A version to inject in the cargo environment variable.   | String | optional | "0.0.0" |
 
 

docs/flatten.md

@@ -906,7 +906,7 @@ When building the whole binary in Bazel, use `rust_library` instead.
 <pre>
 rust_test(<a href="#rust_test-name">name</a>, <a href="#rust_test-aliases">aliases</a>, <a href="#rust_test-compile_data">compile_data</a>, <a href="#rust_test-crate">crate</a>, <a href="#rust_test-crate_features">crate_features</a>, <a href="#rust_test-crate_name">crate_name</a>, <a href="#rust_test-crate_root">crate_root</a>, <a href="#rust_test-data">data</a>, <a href="#rust_test-deps">deps</a>,
           <a href="#rust_test-edition">edition</a>, <a href="#rust_test-env">env</a>, <a href="#rust_test-out_dir_tar">out_dir_tar</a>, <a href="#rust_test-proc_macro_deps">proc_macro_deps</a>, <a href="#rust_test-rustc_env">rustc_env</a>, <a href="#rust_test-rustc_env_files">rustc_env_files</a>, <a href="#rust_test-rustc_flags">rustc_flags</a>, <a href="#rust_test-srcs">srcs</a>,
-          <a href="#rust_test-version">version</a>)
+          <a href="#rust_test-use_libtest_harness">use_libtest_harness</a>, <a href="#rust_test-version">version</a>)
 </pre>
 
 Builds a Rust test crate.
@@ -1059,6 +1059,7 @@ Run the test with `bazel build //hello_lib:hello_lib_test`.
 | <a id="rust_test-rustc_env_files"></a>rustc_env_files |  Files containing additional environment variables to set for rustc.<br><br>These files should  contain a single variable per line, of format <code>NAME=value</code>, and newlines may be included in a value by ending a line with a trailing back-slash (<code>\</code>).<br><br>The order that these files will be processed is unspecified, so multiple definitions of a particular variable are discouraged.   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
 | <a id="rust_test-rustc_flags"></a>rustc_flags |  List of compiler flags passed to <code>rustc</code>.   | List of strings | optional | [] |
 | <a id="rust_test-srcs"></a>srcs |  List of Rust <code>.rs</code> source files used to build the library.<br><br>If <code>srcs</code> contains more than one file, then there must be a file either named <code>lib.rs</code>. Otherwise, <code>crate_root</code> must be set to the source file that is the root of the crate to be passed to rustc to build this crate.   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
+| <a id="rust_test-use_libtest_harness"></a>use_libtest_harness |  Whether to use libtest.   | Boolean | optional | True |
 | <a id="rust_test-version"></a>version |  A version to inject in the cargo environment variable.   | String | optional | "0.0.0" |
 
 

rust/private/rust.bzl

@@ -437,7 +437,7 @@ def _rust_test_common(ctx, toolchain, output):
         toolchain = toolchain,
         crate_type = crate_type,
         crate_info = crate_info,
-        rust_flags = ["--test"],
+        rust_flags = ["--test"] if ctx.attr.use_libtest_harness else ["--cfg", "test"],
     )
 
     return _create_test_launcher(ctx, toolchain, output, providers)
@@ -703,6 +703,13 @@ _rust_test_attrs = {
             ["Make variable"](https://docs.bazel.build/versions/master/be/make-variables.html) substitution.
         """),
     ),
+    "use_libtest_harness": attr.bool(
+        mandatory = False,
+        default = True,
+        doc = _tidy("""\
+            Whether to use libtest.
+        """),
+    ),
     "_launcher": attr.label(
         executable = True,
         default = Label("//util/launcher:launcher"),

test/unit/common.bzl

@@ -28,3 +28,60 @@ def assert_argv_contains_prefix_suffix(env, action, prefix, suffix):
             args = action.argv,
         ),
     )
+
+def assert_action_mnemonic(env, action, mnemonic):
+    if not action.mnemonic == mnemonic:
+        unittest.fail(
+            env,
+            "Expected the action to have the mnemonic '{expected}', but got '{actual}'".format(
+                expected = mnemonic,
+                actual = action.mnemonic,
+            ),
+        )
+
+def _startswith(list, prefix):
+    if len(list) < len(prefix):
+        return False
+    for pair in zip(list[:len(prefix) + 1], prefix):
+        if pair[0] != pair[1]:
+            return False
+    return True
+
+def assert_list_contains_adjacent_elements(env, list_under_test, adjacent_elements):
+    """Assert that list_under_test contains given adjacent flags.
+
+    Args:
+          env: env from analysistest.begin(ctx).
+          list_under_test: list supposed to contain adjacent elements.
+          adjacent_elements: list of elements to be found inside list_under_test.
+    """
+    for idx in range(len(list_under_test)):
+        if list_under_test[idx] == adjacent_elements[0]:
+            if _startswith(list_under_test[idx:], adjacent_elements):
+                return
+
+    unittest.fail(
+        env,
+        "Expected the to find '{expected}' within '{actual}'".format(
+            expected = adjacent_elements,
+            actual = list_under_test,
+        ),
+    )
+
+def assert_list_contains_adjacent_elements_not(env, list_under_test, adjacent_elements):
+    """Assert that list_under_test does not contains given adjacent flags.
+
+    Args:
+          env: env from analysistest.begin(ctx).
+          list_under_test: list supposed not to contain adjacent elements.
+          adjacent_elements: list of elements not to be found inside list_under_test."""
+    for idx in range(len(list_under_test)):
+        if list_under_test[idx] == adjacent_elements[0]:
+            if _startswith(list_under_test[idx:], adjacent_elements):
+                unittest.fail(
+                    env,
+                    "Expected not the to find '{expected}' within '{actual}'".format(
+                        expected = adjacent_elements,
+                        actual = list_under_test,
+                    ),
+                )

test/unit/use_libtest_harness/BUILD.bazel

@@ -0,0 +1,4 @@
+load(":use_libtest_harness_test.bzl", "use_libtest_harness_test_suite")
+
+############################ UNIT TESTS #############################
+use_libtest_harness_test_suite(name = "use_libtest_harness_test_suite")

test/unit/use_libtest_harness/mytest_noharness.rs

@@ -0,0 +1 @@
+fn main() {}

test/unit/use_libtest_harness/use_libtest_harness_test.bzl

@@ -0,0 +1,66 @@
+"""Unittest to verify ordering of rust stdlib in rust_library() CcInfo"""
+
+load("@bazel_skylib//lib:unittest.bzl", "analysistest")
+load("//rust:defs.bzl", "rust_test")
+load("//test/unit:common.bzl", "assert_action_mnemonic", "assert_argv_contains", "assert_argv_contains_not", "assert_list_contains_adjacent_elements", "assert_list_contains_adjacent_elements_not")
+
+def _use_libtest_harness_rustc_flags_test_impl(ctx):
+    env = analysistest.begin(ctx)
+    tut = analysistest.target_under_test(env)
+    action = tut.actions[0]
+    argv = action.argv
+    assert_action_mnemonic(env, action, "Rustc")
+    assert_argv_contains(env, action, "test/unit/use_libtest_harness/mytest.rs")
+    assert_argv_contains(env, action, "--test")
+    assert_list_contains_adjacent_elements_not(env, action.argv, ["--cfg", "test"])
+    return analysistest.end(env)
+
+def _use_libtest_harness_rustc_noharness_flags_test_impl(ctx):
+    env = analysistest.begin(ctx)
+    tut = analysistest.target_under_test(env)
+    action = tut.actions[0]
+    assert_action_mnemonic(env, action, "Rustc")
+    assert_argv_contains(env, action, "test/unit/use_libtest_harness/mytest_noharness.rs")
+    assert_argv_contains_not(env, action, "--test")
+    assert_list_contains_adjacent_elements(env, action.argv, ["--cfg", "test"])
+    return analysistest.end(env)
+
+use_libtest_harness_rustc_flags_test = analysistest.make(_use_libtest_harness_rustc_flags_test_impl)
+use_libtest_harness_rustc_noharness_flags_test = analysistest.make(_use_libtest_harness_rustc_noharness_flags_test_impl)
+
+def _use_libtest_harness_test():
+    rust_test(
+        name = "mytest",
+        srcs = ["mytest.rs"],
+    )
+
+    rust_test(
+        name = "mytest_noharness",
+        srcs = ["mytest_noharness.rs"],
+        use_libtest_harness = False,
+    )
+
+    use_libtest_harness_rustc_flags_test(
+        name = "use_libtest_harness_rustc_flags_test",
+        target_under_test = ":mytest",
+    )
+
+    use_libtest_harness_rustc_noharness_flags_test(
+        name = "use_libtest_harness_rustc_noharness_flags_test",
+        target_under_test = ":mytest_noharness",
+    )
+
+def use_libtest_harness_test_suite(name):
+    """Entry-point macro called from the BUILD file.
+
+    Args:
+        name: Name of the macro.
+    """
+    _use_libtest_harness_test()
+
+    native.test_suite(
+        name = name,
+        tests = [
+            ":use_libtest_harness_rustc_flags_test",
+        ],
+    )