Fix single value inheritance

Single-value product variables resolve to the first
instance of that variable in prefix order. What we
have right now is taking the value from the current
makefile if it's set, but if it's not, we take it
from the last child, not the first.

Fixes: 226206409
Test: Manually
Change-Id: Id23f7c269ff9a352bf0b67cb57156b72449f978e

6 files changed, 99 insertions, 1 deletions

diff --git a/core/product_config.rbc b/core/product_config.rbc
index 8f27c998d7..eab149a8da 100644
--- a/core/product_config.rbc
+++ b/core/product_config.rbc
@@ -291,7 +291,10 @@ def _percolate_inherited(configs, cfg_name, cfg, children_names):
         child_cfg = configs[child_name][1]
         for attr, value in child_cfg.items():
             if type(value) != "list":
-                if attr in percolated_attrs or not attr in cfg:
+                # Single value variables take the first value available from the leftmost
+                # branch of the tree. If we also had "or attr in percolated_attrs" in this
+                # if statement, it would take the value from the rightmost branch.
+                if cfg.get(attr, "") == "":
                     cfg[attr] = value
                     percolated_attrs[attr] = True
                 continue
diff --git a/tests/run.rbc b/tests/run.rbc
index b82887f003..a9b16734d5 100644
--- a/tests/run.rbc
+++ b/tests/run.rbc
@@ -25,6 +25,7 @@ load(":input_variables.rbc", input_variables_init = "init")
 load(":product.rbc", "init")
 load(":board.rbc", board_init = "init")
 load(":board_input_vars.rbc", board_input_vars_init = "init")
+load("//build/make/tests/single_value_inheritance:test.rbc", test_single_value_inheritance = "test")
 
 def assert_eq(expected, actual):
     if expected != actual:
@@ -129,3 +130,5 @@ assert_eq(
 (board_globals, board_config, board_globals_base) = rblf.board_configuration(board_init, board_input_vars_init)
 assert_eq({"A_LIST_VARIABLE": ["foo", "bar"]}, board_globals)
 assert_eq({"A_LIST_VARIABLE": ["foo"]}, board_globals_base)
+
+test_single_value_inheritance()
diff --git a/tests/single_value_inheritance/inherit1.rbc b/tests/single_value_inheritance/inherit1.rbc
new file mode 100644
index 0000000000..b71ffb342e
--- /dev/null
+++ b/tests/single_value_inheritance/inherit1.rbc
@@ -0,0 +1,21 @@
+# Copyright 2022 Google LLC
+#
+# 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
+#
+#      https://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.
+
+load("//build/make/core:product_config.rbc", "rblf")
+
+def init(g, handle):
+  cfg = rblf.cfg(handle)
+
+  cfg["PRODUCT_CHARACTERISTICS"] = "tablet"
+  cfg["PRODUCT_DEFAULT_DEV_CERTIFICATE"] = "vendor/myvendor/certs/devkeys/devkey"
diff --git a/tests/single_value_inheritance/inherit2.rbc b/tests/single_value_inheritance/inherit2.rbc
new file mode 100644
index 0000000000..be85866ffe
--- /dev/null
+++ b/tests/single_value_inheritance/inherit2.rbc
@@ -0,0 +1,20 @@
+# Copyright 2022 Google LLC
+#
+# 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
+#
+#      https://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.
+
+load("//build/make/core:product_config.rbc", "rblf")
+
+def init(g, handle):
+  cfg = rblf.cfg(handle)
+
+  cfg["PRODUCT_CHARACTERISTICS"] = "nosdcard"
diff --git a/tests/single_value_inheritance/product.rbc b/tests/single_value_inheritance/product.rbc
new file mode 100644
index 0000000000..332704351f
--- /dev/null
+++ b/tests/single_value_inheritance/product.rbc
@@ -0,0 +1,24 @@
+# Copyright 2022 Google LLC
+#
+# 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
+#
+#      https://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.
+
+load("//build/make/core:product_config.rbc", "rblf")
+load(":inherit1.rbc", _inherit1_init = "init")
+load(":inherit2.rbc", _inherit2_init = "init")
+
+def init(g, handle):
+  cfg = rblf.cfg(handle)
+  rblf.inherit(handle, "test/inherit1", _inherit1_init)
+  rblf.inherit(handle, "test/inherit2", _inherit2_init)
+
+  cfg["PRODUCT_DEFAULT_DEV_CERTIFICATE"] = ""
diff --git a/tests/single_value_inheritance/test.rbc b/tests/single_value_inheritance/test.rbc
new file mode 100644
index 0000000000..07a5e65cd5
--- /dev/null
+++ b/tests/single_value_inheritance/test.rbc
@@ -0,0 +1,27 @@
+# Copyright 2022 Google LLC
+#
+# 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
+#
+#      https://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.
+
+load("//build/make/core:product_config.rbc", "rblf")
+load("//build/make/tests/input_variables.rbc", input_variables_init = "init")
+load(":product.rbc", "init")
+
+
+def assert_eq(expected, actual):
+    if expected != actual:
+        fail("Expected '%s', got '%s'" % (expected, actual))
+
+def test():
+    (globals, config, globals_base) = rblf.product_configuration("test/device", init, input_variables_init)
+    assert_eq("tablet", config["PRODUCT_CHARACTERISTICS"])
+    assert_eq("vendor/myvendor/certs/devkeys/devkey", config["PRODUCT_DEFAULT_DEV_CERTIFICATE"])