1 files changed, 190 insertions, 0 deletions
diff --git a/tools/product_config/src/com/android/build/config/OutputChecker.java b/tools/product_config/src/com/android/build/config/OutputChecker.java
new file mode 100644
index 0000000000..d982dba7ed
--- /dev/null
+++ b/tools/product_config/src/com/android/build/config/OutputChecker.java
@@ -0,0 +1,190 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * 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.
+ */
+
+package com.android.build.config;
+
+import java.util.Arrays;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
+/**
+ * Compares the make-based configuration as reported by dumpconfig.mk
+ * with what was computed from the new tool.
+ */
+public class OutputChecker {
+    // Differences that we know about, either know issues to be fixed or intentional.
+    private static final RegexSet IGNORED_VARIABLES = new RegexSet(
+            // TODO: Rewrite the enforce packages exist logic into this tool.
+            "PRODUCT_ENFORCE_PACKAGES_EXIST",
+            "PRODUCT_ENFORCE_PACKAGES_EXIST_ALLOW_LIST",
+            "PRODUCTS\\..*\\.PRODUCT_ENFORCE_PACKAGES_EXIST",
+            "PRODUCTS\\..*\\.PRODUCT_ENFORCE_PACKAGES_EXIST_ALLOW_LIST",
+
+            // This is generated by this tool, but comes later in the make build system.
+            "INTERNAL_PRODUCT",
+
+            // This can be set temporarily by product_config.mk
+            ".KATI_ALLOW_RULES"
+            );
+
+    private final FlatConfig mConfig;
+    private final TreeMap<String, Variable> mVariables;
+
+    /**
+     * Represents the before and after state of a variable.
+     */
+    public static class Variable {
+        public final String name;
+        public final VarType type;
+        public final Str original;
+        public final Value updated;
+
+        public Variable(String name, VarType type, Str original) {
+            this(name, type, original, null);
+        }
+
+        public Variable(String name, VarType type, Str original, Value updated) {
+            this.name = name;
+            this.type = type;
+            this.original = original;
+            this.updated = updated;
+        }
+
+        /**
+         * Return copy of this Variable with the updated field also set.
+         */
+        public Variable addUpdated(Value updated) {
+            return new Variable(name, type, original, updated);
+        }
+
+        /**
+         * Return whether normalizedOriginal and normalizedUpdate are equal.
+         */
+        public boolean isSame() {
+            final Str normalizedOriginal = Value.normalize(original);
+            final Str normalizedUpdated = Value.normalize(updated);
+            if (normalizedOriginal == null && normalizedUpdated == null) {
+                return true;
+            } else if (normalizedOriginal != null) {
+                return normalizedOriginal.equals(normalizedUpdated);
+            } else {
+                return false;
+            }
+        }
+    }
+
+    /**
+     * Construct OutputChecker with the config it will check.
+     */
+    public OutputChecker(FlatConfig config) {
+        mConfig = config;
+        mVariables = getVariables(config);
+    }
+
+    /**
+     * Add a WARNING_DIFFERENT_FROM_KATI for each of the variables which have changed.
+     */
+    public void reportErrors(Errors errors) {
+        for (Variable var: getDifferences()) {
+            if (IGNORED_VARIABLES.matches(var.name)) {
+                continue;
+            }
+            errors.WARNING_DIFFERENT_FROM_KATI.add("product_config processing differs from"
+                    + " kati processing for " + var.type + " variable " + var.name + ".\n"
+                    + "original: "
+                    + Value.oneLinePerWord(var.original, "<null>") + "\n"
+                    + "updated: "
+                    + Value.oneLinePerWord(var.updated, "<null>"));
+        }
+    }
+
+    /**
+     * Get the Variables that are different between the normalized form of the original
+     * and updated.  If one is null and the other is not, even if one is an empty string,
+     * the values are considered different.
+     */
+    public List<Variable> getDifferences() {
+        final ArrayList<Variable> result = new ArrayList();
+        for (Variable var: mVariables.values()) {
+            if (!var.isSame()) {
+                result.add(var);
+            }
+        }
+        return result;
+    }
+
+    /**
+     * Get all of the variables for this config.
+     *
+     * VisibleForTesting
+     */
+    static TreeMap<String, Variable> getVariables(FlatConfig config) {
+        final TreeMap<String, Variable> result = new TreeMap();
+
+        // Add the original values to mAll
+        for (Map.Entry<String, Str> entry: getModifiedVars(config.getInitialVariables(),
+                    config.getFinalVariables()).entrySet()) {
+            final String name = entry.getKey();
+            result.put(name, new Variable(name, config.getVarType(name), entry.getValue()));
+        }
+
+        // Add the updated values to mAll
+        for (Map.Entry<String, Value> entry: config.getValues().entrySet()) {
+            final String name = entry.getKey();
+            final Value value = entry.getValue();
+            Variable var = result.get(name);
+            if (var == null) {
+                result.put(name, new Variable(name, config.getVarType(name), null, value));
+            } else {
+                result.put(name, var.addUpdated(value));
+            }
+        }
+
+        return result;
+    }
+
+    /**
+     * Get the entries that are different in the two maps.
+     */
+    public static Map<String, Str> getModifiedVars(Map<String, Str> before,
+            Map<String, Str> after) {
+        final HashMap<String, Str> result = new HashMap();
+
+        // Entries that were added or changed.
+        for (Map.Entry<String, Str> afterEntry: after.entrySet()) {
+            final String varName = afterEntry.getKey();
+            final Str afterValue = afterEntry.getValue();
+            final Str beforeValue = before.get(varName);
+            if (beforeValue == null || !beforeValue.equals(afterValue)) {
+                result.put(varName, afterValue);
+            }
+        }
+
+        // removed Entries that were removed, we just treat them as empty string
+        for (Map.Entry<String, Str> beforeEntry: before.entrySet()) {
+            final String varName = beforeEntry.getKey();
+            if (!after.containsKey(varName)) {
+                result.put(varName, new Str(""));
+            }
+        }
+
+        return result;
+    }
+}