selects.bzl: Add config_setting_group for config_setting AND/OR-chaining (#89)

* Add config_setting_group for config_setting AND/OR-chaining

Implements https://github.com/bazelbuild/proposals/blob/master/designs/2018-11-09-config-setting-chaining.md.

* buildifier lint fixes

* Add tests

* Add test stub for both match_any and match_all

* Simplify the implementation and make it more correct. :)

* Fix styling issues

1 files changed, 521 insertions, 1 deletions

diff --git a/tests/selects_tests.bzl b/tests/selects_tests.bzl
index b9a354d..1d77cee 100644
--- a/tests/selects_tests.bzl
+++ b/tests/selects_tests.bzl
@@ -15,8 +15,11 @@
 """Unit tests for selects.bzl."""
 
 load("//lib:selects.bzl", "selects")
-load("//lib:unittest.bzl", "asserts", "unittest")
+load("//lib:unittest.bzl", "analysistest", "asserts", "unittest")
 
+###################################################
+# with_or_test
+###################################################
 def _with_or_test(ctx):
     """Unit tests for with_or."""
     env = unittest.begin(ctx)
@@ -57,9 +60,526 @@ def _with_or_test(ctx):
 
 with_or_test = unittest.make(_with_or_test)
 
+###################################################
+# BUILD declarations for config_setting_group tests
+###################################################
+
+# TODO: redefine these config_settings with Starlark build flags when
+# they're available non-experimentally.
+def _create_config_settings():
+    native.config_setting(
+        name = "condition1",
+        values = {"cpu": "ppc"},
+    )
+    native.config_setting(
+        name = "condition2",
+        values = {"compilation_mode": "opt"},
+    )
+    native.config_setting(
+        name = "condition3",
+        values = {"features": "myfeature"},
+    )
+
+def _create_config_setting_groups():
+    selects.config_setting_group(
+        name = "1_and_2_and_3",
+        match_all = [":condition1", ":condition2", ":condition3"],
+    )
+    selects.config_setting_group(
+        name = "1_and_nothing_else",
+        match_all = [":condition1"],
+    )
+    selects.config_setting_group(
+        name = "1_or_2_or_3",
+        match_any = [":condition1", ":condition2", ":condition3"],
+    )
+    selects.config_setting_group(
+        name = "1_or_nothing_else",
+        match_any = [":condition1"],
+    )
+
+###################################################
+# Support code for config_setting_group tests
+###################################################
+
+def _set_conditions(condition_list):
+    """Returns an argument for config_settings that sets specific options.
+
+    Args:
+      condition_list: a list of three booleans
+
+    Returns:
+      a dictionary parameter for config_settings such that ":conditionN" is True
+          iff condition_list[N + 1] is True
+    """
+    if len(condition_list) != 3:
+        fail("condition_list must be a list of 3 booleans")
+    ans = {}
+    if condition_list[0]:
+        ans["//command_line_option:cpu"] = "ppc"
+    if condition_list[1]:
+        ans["//command_line_option:compilation_mode"] = "opt"
+    if condition_list[2]:
+        ans["//command_line_option:features"] = ["myfeature"]
+    return ans
+
+_BooleanInfo = provider()
+
+def _boolean_attr_impl(ctx):
+    return [_BooleanInfo(value = ctx.attr.myboolean)]
+
+boolean_attr_rule = rule(
+    implementation = _boolean_attr_impl,
+    attrs = {"myboolean": attr.bool()},
+)
+
+def _expect_matches(ctx):
+    """Generic test implementation expecting myboolean == True."""
+    env = analysistest.begin(ctx)
+    attrval = analysistest.target_under_test(env)[_BooleanInfo].value
+    asserts.equals(env, True, attrval)
+    return analysistest.end(env)
+
+def _expect_doesnt_match(ctx):
+    """Generic test implementation expecting myboolean == False."""
+    env = analysistest.begin(ctx)
+    attrval = analysistest.target_under_test(env)[_BooleanInfo].value
+    asserts.equals(env, False, attrval)
+    return analysistest.end(env)
+
+def _config_setting_group_test(name, config_settings):
+    return analysistest.make()
+
+###################################################
+# and_config_setting_group_matches_test
+###################################################
+and_config_setting_group_matches_test = analysistest.make(
+    _expect_matches,
+    config_settings = _set_conditions([True, True, True]),
+)
+
+def _and_config_setting_group_matches_test():
+    """Test verifying match on an ANDing config_setting_group."""
+    boolean_attr_rule(
+        name = "and_config_setting_group_matches_rule",
+        myboolean = select(
+            {
+                ":1_and_2_and_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    and_config_setting_group_matches_test(
+        name = "and_config_setting_group_matches_test",
+        target_under_test = ":and_config_setting_group_matches_rule",
+    )
+
+###################################################
+# and_config_setting_group_first_match_fails_test
+###################################################
+and_config_setting_group_first_match_fails_test = analysistest.make(
+    _expect_doesnt_match,
+    config_settings = _set_conditions([False, True, True]),
+)
+
+def _and_config_setting_group_first_match_fails_test():
+    """Test verifying first condition mismatch on an ANDing config_setting_group."""
+    boolean_attr_rule(
+        name = "and_config_setting_group_first_match_fails_rule",
+        myboolean = select(
+            {
+                ":1_and_2_and_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    and_config_setting_group_first_match_fails_test(
+        name = "and_config_setting_group_first_match_fails_test",
+        target_under_test = ":and_config_setting_group_first_match_fails_rule",
+    )
+
+###################################################
+# and_config_setting_group_middle_match_fails_test
+###################################################
+and_config_setting_group_middle_match_fails_test = analysistest.make(
+    _expect_doesnt_match,
+    config_settings = _set_conditions([True, False, True]),
+)
+
+def _and_config_setting_group_middle_match_fails_test():
+    """Test verifying middle condition mismatch on an ANDing config_setting_group."""
+    boolean_attr_rule(
+        name = "and_config_setting_group_middle_match_fails_rule",
+        myboolean = select(
+            {
+                ":1_and_2_and_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    and_config_setting_group_middle_match_fails_test(
+        name = "and_config_setting_group_middle_match_fails_test",
+        target_under_test = ":and_config_setting_group_middle_match_fails_rule",
+    )
+
+###################################################
+# and_config_setting_group_last_match_fails_test
+###################################################
+and_config_setting_group_last_match_fails_test = analysistest.make(
+    _expect_doesnt_match,
+    config_settings = _set_conditions([True, True, False]),
+)
+
+def _and_config_setting_group_last_match_fails_test():
+    """Test verifying last condition mismatch on an ANDing config_setting_group."""
+    boolean_attr_rule(
+        name = "and_config_setting_group_last_match_fails_rule",
+        myboolean = select(
+            {
+                ":1_and_2_and_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    and_config_setting_group_last_match_fails_test(
+        name = "and_config_setting_group_last_match_fails_test",
+        target_under_test = ":and_config_setting_group_last_match_fails_rule",
+    )
+
+###################################################
+# and_config_setting_group_multiple_matches_fail_test
+###################################################
+and_config_setting_group_multiple_matches_fail_test = analysistest.make(
+    _expect_doesnt_match,
+    config_settings = _set_conditions([True, False, False]),
+)
+
+def _and_config_setting_group_multiple_matches_fail_test():
+    """Test verifying multple conditions mismatch on an ANDing config_setting_group."""
+    boolean_attr_rule(
+        name = "and_config_setting_group_multiple_matches_fail_rule",
+        myboolean = select(
+            {
+                ":1_and_2_and_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    and_config_setting_group_multiple_matches_fail_test(
+        name = "and_config_setting_group_multiple_matches_fail_test",
+        target_under_test = ":and_config_setting_group_multiple_matches_fail_rule",
+    )
+
+###################################################
+# and_config_setting_group_all_matches_fail_test
+###################################################
+and_config_setting_group_all_matches_fail_test = analysistest.make(
+    _expect_doesnt_match,
+    config_settings = _set_conditions([False, False, False]),
+)
+
+def _and_config_setting_group_all_matches_fail_test():
+    """Test verifying all conditions mismatch on an ANDing config_setting_group."""
+    boolean_attr_rule(
+        name = "and_config_setting_group_all_matches_fail_rule",
+        myboolean = select(
+            {
+                ":1_and_2_and_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    and_config_setting_group_all_matches_fail_test(
+        name = "and_config_setting_group_all_matches_fail_test",
+        target_under_test = ":and_config_setting_group_all_matches_fail_rule",
+    )
+
+###################################################
+# and_config_setting_group_single_setting_matches_test
+###################################################
+and_config_setting_group_single_setting_matches_test = analysistest.make(
+    _expect_matches,
+    config_settings = {"//command_line_option:cpu": "ppc"},
+)
+
+def _and_config_setting_group_single_setting_matches_test():
+    """Test verifying match on single-entry ANDing config_setting_group."""
+    boolean_attr_rule(
+        name = "and_config_setting_group_single_setting_matches_rule",
+        myboolean = select(
+            {
+                ":1_and_nothing_else": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    and_config_setting_group_single_setting_matches_test(
+        name = "and_config_setting_group_single_setting_matches_test",
+        target_under_test = ":and_config_setting_group_single_setting_matches_rule",
+    )
+
+###################################################
+# and_config_setting_group_single_setting_fails_test
+###################################################
+and_config_setting_group_single_setting_fails_test = analysistest.make(
+    _expect_doesnt_match,
+    config_settings = {"//command_line_option:cpu": "x86"},
+)
+
+def _and_config_setting_group_single_setting_fails_test():
+    """Test verifying no match on single-entry ANDing config_setting_group."""
+    boolean_attr_rule(
+        name = "and_config_setting_group_single_setting_fails_rule",
+        myboolean = select(
+            {
+                ":1_and_nothing_else": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    and_config_setting_group_single_setting_fails_test(
+        name = "and_config_setting_group_single_setting_fails_test",
+        target_under_test = ":and_config_setting_group_single_setting_fails_rule",
+    )
+
+###################################################
+# or_config_setting_group_no_match_test
+###################################################
+or_config_setting_group_no_matches_test = analysistest.make(
+    _expect_doesnt_match,
+    config_settings = _set_conditions([False, False, False]),
+)
+
+def _or_config_setting_group_no_matches_test():
+    """Test verifying no matches on an ORing config_setting_group."""
+    boolean_attr_rule(
+        name = "or_config_setting_group_no_matches_rule",
+        myboolean = select(
+            {
+                ":1_or_2_or_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    or_config_setting_group_no_matches_test(
+        name = "or_config_setting_group_no_matches_test",
+        target_under_test = ":or_config_setting_group_no_matches_rule",
+    )
+
+###################################################
+# or_config_setting_group_first_cond_matches_test
+###################################################
+or_config_setting_group_first_cond_matches_test = analysistest.make(
+    _expect_matches,
+    config_settings = _set_conditions([True, False, False]),
+)
+
+def _or_config_setting_group_first_cond_matches_test():
+    """Test verifying first condition matching on an ORing config_setting_group."""
+    boolean_attr_rule(
+        name = "or_config_setting_group_first_cond_matches_rule",
+        myboolean = select(
+            {
+                ":1_or_2_or_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    or_config_setting_group_first_cond_matches_test(
+        name = "or_config_setting_group_first_cond_matches_test",
+        target_under_test = ":or_config_setting_group_first_cond_matches_rule",
+    )
+
+###################################################
+# or_config_setting_group_middle_cond_matches_test
+###################################################
+or_config_setting_group_middle_cond_matches_test = analysistest.make(
+    _expect_matches,
+    config_settings = _set_conditions([False, True, False]),
+)
+
+def _or_config_setting_group_middle_cond_matches_test():
+    """Test verifying middle condition matching on an ORing config_setting_group."""
+    boolean_attr_rule(
+        name = "or_config_setting_group_middle_cond_matches_rule",
+        myboolean = select(
+            {
+                ":1_or_2_or_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    or_config_setting_group_middle_cond_matches_test(
+        name = "or_config_setting_group_middle_cond_matches_test",
+        target_under_test = ":or_config_setting_group_middle_cond_matches_rule",
+    )
+
+###################################################
+# or_config_setting_group_last_cond_matches_test
+###################################################
+or_config_setting_group_last_cond_matches_test = analysistest.make(
+    _expect_matches,
+    config_settings = _set_conditions([False, False, True]),
+)
+
+def _or_config_setting_group_last_cond_matches_test():
+    """Test verifying last condition matching on an ORing config_setting_group."""
+    boolean_attr_rule(
+        name = "or_config_setting_group_last_cond_matches_rule",
+        myboolean = select(
+            {
+                ":1_or_2_or_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    or_config_setting_group_last_cond_matches_test(
+        name = "or_config_setting_group_last_cond_matches_test",
+        target_under_test = ":or_config_setting_group_last_cond_matches_rule",
+    )
+
+###################################################
+# or_config_setting_group_multiple_conds_match_test
+###################################################
+or_config_setting_group_multiple_conds_match_test = analysistest.make(
+    _expect_matches,
+    config_settings = _set_conditions([False, True, True]),
+)
+
+def _or_config_setting_group_multiple_conds_match_test():
+    """Test verifying multple conditions matching on an ORing config_setting_group."""
+    boolean_attr_rule(
+        name = "or_config_setting_group_multiple_conds_match_rule",
+        myboolean = select(
+            {
+                ":1_or_2_or_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    or_config_setting_group_multiple_conds_match_test(
+        name = "or_config_setting_group_multiple_conds_match_test",
+        target_under_test = ":or_config_setting_group_multiple_conds_match_rule",
+    )
+
+###################################################
+# or_config_setting_group_all_conds_match_test
+###################################################
+or_config_setting_group_all_conds_match_test = analysistest.make(
+    _expect_matches,
+    config_settings = _set_conditions([False, True, True]),
+)
+
+def _or_config_setting_group_all_conds_match_test():
+    """Test verifying all conditions matching on an ORing config_setting_group."""
+    boolean_attr_rule(
+        name = "or_config_setting_group_all_conds_match_rule",
+        myboolean = select(
+            {
+                ":1_or_2_or_3": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    or_config_setting_group_all_conds_match_test(
+        name = "or_config_setting_group_all_conds_match_test",
+        target_under_test = ":or_config_setting_group_all_conds_match_rule",
+    )
+
+###################################################
+# or_config_setting_group_single_setting_matches_test
+###################################################
+or_config_setting_group_single_setting_matches_test = analysistest.make(
+    _expect_matches,
+    config_settings = {"//command_line_option:cpu": "ppc"},
+)
+
+def _or_config_setting_group_single_setting_matches_test():
+    """Test verifying match on single-entry ORing config_setting_group."""
+    boolean_attr_rule(
+        name = "or_config_setting_group_single_setting_matches_rule",
+        myboolean = select(
+            {
+                ":1_or_nothing_else": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    or_config_setting_group_single_setting_matches_test(
+        name = "or_config_setting_group_single_setting_matches_test",
+        target_under_test = ":or_config_setting_group_single_setting_matches_rule",
+    )
+
+###################################################
+# or_config_setting_group_single_setting_fails_test
+###################################################
+or_config_setting_group_single_setting_fails_test = analysistest.make(
+    _expect_doesnt_match,
+    config_settings = {"//command_line_option:cpu": "x86"},
+)
+
+def _or_config_setting_group_single_setting_fails_test():
+    """Test verifying no match on single-entry ORing config_setting_group."""
+    boolean_attr_rule(
+        name = "or_config_setting_group_single_setting_fails_rule",
+        myboolean = select(
+            {
+                ":1_or_nothing_else": True,
+                "//conditions:default": False,
+            },
+        ),
+    )
+    or_config_setting_group_single_setting_fails_test(
+        name = "or_config_setting_group_single_setting_fails_test",
+        target_under_test = ":or_config_setting_group_single_setting_fails_rule",
+    )
+
+###################################################
+# empty_config_setting_group_not_allowed_test
+###################################################
+
+# config_setting_group with no parameters triggers a failure.
+# TODO: how do we test this? This requires catching macro
+# evaluation failure.
+
+###################################################
+# and_and_or_not_allowed_together_test
+###################################################
+
+# config_setting_group: setting both match_any and match_or
+# triggers a failure.
+# TODO: how do we test this? This requires catching macro
+# evaluation failure.
+
+###################################################
+
 def selects_test_suite():
     """Creates the test targets and test suite for selects.bzl tests."""
     unittest.suite(
         "selects_tests",
         with_or_test,
     )
+
+    _create_config_settings()
+    _create_config_setting_groups()
+
+    _and_config_setting_group_matches_test()
+    _and_config_setting_group_first_match_fails_test()
+    _and_config_setting_group_middle_match_fails_test()
+    _and_config_setting_group_last_match_fails_test()
+    _and_config_setting_group_multiple_matches_fail_test()
+    _and_config_setting_group_all_matches_fail_test()
+    _and_config_setting_group_single_setting_matches_test()
+    _and_config_setting_group_single_setting_fails_test()
+
+    _or_config_setting_group_no_matches_test()
+    _or_config_setting_group_first_cond_matches_test()
+    _or_config_setting_group_middle_cond_matches_test()
+    _or_config_setting_group_last_cond_matches_test()
+    _or_config_setting_group_multiple_conds_match_test()
+    _or_config_setting_group_all_conds_match_test()
+    _or_config_setting_group_single_setting_matches_test()
+    _or_config_setting_group_single_setting_fails_test()
+
+    # _empty_config_setting_group_not_allowed_test()
+    # _and_and_or_not_allowed_together_test()