Make Skylark interpreter read Skylark command-line flags

This is the second of two CLs for making command line options able to affect the Skylark interpreter. For the main kinds of evaluation contexts -- package loading, .bzl loading, rule analysis, aspect analysis, and computed defaults -- the SkylarkSemanticsOptions object is retrieved from Skyframe and passed along to the Environment builder. For other contexts such as tests, default values of builtin functions, and standalone Skylark, flags are currently not processed.

In the future, we may want to split into separate files the options that affect "pure" Skylark vs the options that affect Bazel-flavored Skylark. One possibility is to subclass SkylarkSemanticsOptions into SkylarkBazelSemanticsOptions, and go through an indirection in SkylarkUtils.

We could also pass SkylarkSemanticsOptions to the parser, to support --incompatible_* changes that alter Skylark's syntax. I don't think that's needed at the moment.

RELNOTES: None
PiperOrigin-RevId: 154628391

1 files changed, 104 insertions, 0 deletions

diff --git a/src/test/shell/integration/skylark_flag_test.sh b/src/test/shell/integration/skylark_flag_test.sh
new file mode 100755
index 0000000000..df12d71259
--- /dev/null
+++ b/src/test/shell/integration/skylark_flag_test.sh
@@ -0,0 +1,104 @@
+#!/bin/bash
+#
+# Copyright 2017 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Tests that the Skylark interpreter is reading flags passed in on the command
+# line, in several different evaluation contexts.
+#
+# The --internal_skylark_flag_test_canary flag is built into
+# SkylarkSemanticsOptions specifically for this test suite.
+
+# Load the test setup defined in the parent directory
+CURRENT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+source "${CURRENT_DIR}/../integration_test_setup.sh" \
+  || { echo "integration_test_setup.sh not found!" >&2; exit 1; }
+
+MARKER="<== skylark flag test ==>"
+
+function setup_package() {
+  mkdir -p test
+  cat > test/BUILD <<'EOF'
+load(":test.bzl", "macro")
+
+print("In BUILD: ")
+
+macro()
+EOF
+  cat >test/test.bzl <<'EOF'
+print("In bzl: ")
+
+def _rule_impl(ctx):
+  print("In rule: ")
+
+some_rule = rule(
+    implementation = _rule_impl,
+)
+
+def _aspect_impl(target, ctx):
+  print("In aspect: ")
+  return []
+
+some_aspect = aspect(
+    implementation = _aspect_impl,
+)
+
+def macro():
+  print("In macro: ")
+  some_rule(name="some_target")
+EOF
+}
+
+function test_sanity() {
+  # Control test: Make sure the print strings appear, and the marker string
+  # doesn't appear, when we don't pass the flag.
+  setup_package
+  bazel build //test:some_target  --aspects test/test.bzl%some_aspect \
+    &>"$TEST_log" || fail "bazel build failed";
+  fail_msg="Marker string '$MARKER' was seen even though "
+  fail_msg+="--internal_skylark_flag_test_canary wasn't passed"
+  expect_not_log "$MARKER" "$fail_msg"
+  expect_log "In BUILD: " "Did not find BUILD print output"
+  expect_log "In bzl: " "Did not find .bzl print output"
+  expect_log "In macro: " "Did not find macro print output"
+  expect_log "In rule: " "Did not find rule print output"
+  # TODO(brandjon): If we add computed default functions as per below, add a
+  # sanity check for it here too.
+  expect_log "In aspect: " "Did not find aspect print output"
+}
+
+function test_skylark_flags() {
+  # Check that the marker string appears when we pass the flag.
+  setup_package
+  bazel build //test:some_target --aspects test/test.bzl%some_aspect \
+    --internal_skylark_flag_test_canary \
+    &>"$TEST_log" || fail "bazel build failed";
+  expect_log "In BUILD: $MARKER" \
+    "Skylark flags are not propagating to BUILD file evaluation"
+  expect_log "In bzl: $MARKER" \
+    "Skylark flags are not propagating to .bzl file evaluation"
+  expect_log "In macro: $MARKER" \
+    "Skylark flags are not propagating to macro evaluation"
+  expect_log "In rule: $MARKER" \
+    "Skylark flags are not propagating to rule implementation function evaluation"
+  # TODO(brandjon): Once we're no long dropping print() output in computed
+  # default functions, also test that we're propagating flags there.
+  # Alternatively, this could be tested by having conditional code that crashes
+  # while evaluating the Skylark function iff the flag is set.
+  expect_log "In aspect: $MARKER" \
+    "Skylark flags are not propagating to aspect implementation function evaluation"
+}
+
+
+run_suite "skylark_flag_test"