Add option to strip annotations from jar am: 47f189c1e4 am: 18e65b195a am: 41407b062f am: 5976f804d3 am: 934d8f06e4

Original change: https://android-review.googlesource.com/c/platform/external/jarjar/+/2092603

Change-Id: I1a46904d929f7c3a173a01f5ae7d33416b093660
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

5 files changed, 171 insertions, 0 deletions

diff --git a/res/com/tonicsystems/jarjar/help.txt b/res/com/tonicsystems/jarjar/help.txt
index 8410909..6f14db6 100644
--- a/res/com/tonicsystems/jarjar/help.txt
+++ b/res/com/tonicsystems/jarjar/help.txt
@@ -49,6 +49,7 @@ Rules file format:
     rule <pattern> <result>
     zap <pattern>
     keep <pattern>
+    strip-annotations <annotation>
 
   The standard rule ("rule") is used to rename classes. All references
   to the renamed classes will also be updated. If a class name is
@@ -73,3 +74,6 @@ Rules file format:
   via dependency analysis are discarded when writing the output
   jar. This is the last step in the process, after renaming and zapping.
 
+  The "strip-annotations" rule will remove all the references to a certain
+  annotation from a jar file. As no pattern matching is performed, the
+  annotations have to be provided as one per line.
diff --git a/src/android/com/android/jarjar/StripAnnotation.java b/src/android/com/android/jarjar/StripAnnotation.java
new file mode 100644
index 0000000..debd469
--- /dev/null
+++ b/src/android/com/android/jarjar/StripAnnotation.java
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2022 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.jarjar;
+
+import com.tonicsystems.jarjar.PatternElement;
+
+/**
+ * Configuration element for stripping annotations in a jar file.
+ */
+public class StripAnnotation extends PatternElement
+{
+}
diff --git a/src/android/com/android/jarjar/StripAnnotationsJarTransformer.java b/src/android/com/android/jarjar/StripAnnotationsJarTransformer.java
new file mode 100644
index 0000000..260cb30
--- /dev/null
+++ b/src/android/com/android/jarjar/StripAnnotationsJarTransformer.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2022 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.jarjar;
+
+import com.tonicsystems.jarjar.util.JarTransformer;
+
+import org.objectweb.asm.AnnotationVisitor;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.FieldVisitor;
+import org.objectweb.asm.MethodVisitor;
+import org.objectweb.asm.Opcodes;
+
+import java.util.List;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+
+/**
+ * A transformer that strips annotations from all classes based on custom rules.
+ */
+public final class StripAnnotationsJarTransformer extends JarTransformer {
+
+    private static int ASM_VERSION = Opcodes.ASM7;
+
+    private final List<String> stripAnnotationList;
+
+    public StripAnnotationsJarTransformer(List<StripAnnotation> stripAnnotationList) {
+        this.stripAnnotationList = getAnnotationList(stripAnnotationList);
+    }
+
+    private static List<String> getAnnotationList(List<StripAnnotation> stripAnnotationList) {
+        return stripAnnotationList.stream().map(el -> getClassName(el)).collect(Collectors.toList());
+    }
+
+    private static String getClassName(StripAnnotation element) {
+        return "L" + element.getPattern().replace('.', '/') + ";";
+    }
+
+    @Override
+    protected ClassVisitor transform(ClassVisitor classVisitor) {
+        return new AnnotationRemover(classVisitor);
+    }
+
+    private class AnnotationRemover extends ClassVisitor {
+
+        AnnotationRemover(ClassVisitor cv) {
+            super(ASM_VERSION, cv);
+        }
+
+        @Override
+        public AnnotationVisitor visitAnnotation(String descriptor, boolean visible) {
+            return visitAnnotationCommon(descriptor,
+                    () -> super.visitAnnotation(descriptor, visible));
+        }
+
+        @Override
+        public FieldVisitor visitField(int access, String name, String descriptor, String signature,
+                Object value) {
+            FieldVisitor superVisitor =
+                    super.visitField(access, name, descriptor, signature, value);
+            return new FieldVisitor(ASM_VERSION, superVisitor) {
+                @Override
+                public AnnotationVisitor visitAnnotation(String descriptor, boolean visible) {
+                    return visitAnnotationCommon(descriptor,
+                            () -> super.visitAnnotation(descriptor, visible));
+
+                }
+            };
+        }
+
+        @Override
+        public MethodVisitor visitMethod(int access, String name, String descriptor,
+                String signature, String[] exceptions) {
+            MethodVisitor superVisitor =
+                    super.visitMethod(access, name, descriptor, signature, exceptions);
+            return new MethodVisitor(ASM_VERSION, superVisitor) {
+                @Override
+                public AnnotationVisitor visitAnnotation(String descriptor, boolean visible) {
+                    return visitAnnotationCommon(descriptor,
+                            () -> super.visitAnnotation(descriptor, visible));
+                }
+
+                @Override
+                public AnnotationVisitor visitParameterAnnotation(int parameter,
+                        String descriptor, boolean visible) {
+                    return visitAnnotationCommon(descriptor,
+                            () -> super.visitParameterAnnotation(parameter, descriptor, visible));
+                }
+            };
+        }
+
+        /**
+         * Create an {@link AnnotationVisitor} that removes any annotations from {@link
+         * #stripAnnotationList}.
+         */
+        private AnnotationVisitor visitAnnotationCommon(String annotation,
+                Supplier<AnnotationVisitor> defaultVisitorSupplier) {
+            if (stripAnnotationList.contains(annotation)) {
+                return null;
+            }
+            // Only get() the default AnnotationVisitor if the annotation is to be included.
+            // Invoking super.visitAnnotation(descriptor, visible) causes the annotation to be
+            // included in the output even if the resulting AnnotationVisitor is not returned or
+            // used.
+            return defaultVisitorSupplier.get();
+        }
+    }
+}
diff --git a/src/main/com/tonicsystems/jarjar/MainProcessor.java b/src/main/com/tonicsystems/jarjar/MainProcessor.java
index 2778cc5..a0ef4c7 100644
--- a/src/main/com/tonicsystems/jarjar/MainProcessor.java
+++ b/src/main/com/tonicsystems/jarjar/MainProcessor.java
@@ -16,12 +16,14 @@
 
 package com.tonicsystems.jarjar;
 
+import com.android.jarjar.StripAnnotation;
 import com.tonicsystems.jarjar.util.*;
 import java.io.File;
 import java.io.IOException;
 import java.util.*;
 
 import com.android.jarjar.RemoveAndroidCompatAnnotationsJarTransformer;
+import com.android.jarjar.StripAnnotationsJarTransformer;
 
 class MainProcessor implements JarProcessor
 {
@@ -42,6 +44,9 @@ class MainProcessor implements JarProcessor
         List<Zap> zapList = new ArrayList<Zap>();
         List<Rule> ruleList = new ArrayList<Rule>();
         List<Keep> keepList = new ArrayList<Keep>();
+        // ANDROID-BEGIN: b/222743634 Strip annotations from system module stubs
+        List<StripAnnotation> stripAnnotationList = new ArrayList<StripAnnotation>();
+        // ANDROID-END: b/222743634 Strip annotations from system module stubs
         for (PatternElement pattern : patterns) {
             if (pattern instanceof Zap) {
                 zapList.add((Zap) pattern);
@@ -49,7 +54,11 @@ class MainProcessor implements JarProcessor
                 ruleList.add((Rule) pattern);
             } else if (pattern instanceof Keep) {
                 keepList.add((Keep) pattern);
+            // ANDROID-BEGIN: b/222743634 Strip annotations from system module stubs
+            } else if (pattern instanceof StripAnnotation) {
+                stripAnnotationList.add((StripAnnotation) pattern);
             }
+            // ANDROID-END: b/222743634 Strip annotations from system module stubs
         }
 
         PackageRemapper pr = new PackageRemapper(ruleList, verbose);
@@ -65,6 +74,11 @@ class MainProcessor implements JarProcessor
         if (removeAndroidCompatAnnotations)
             processors.add(new RemoveAndroidCompatAnnotationsJarTransformer(pr));
         // ANDROID-END: b/146418363 Add an Android-specific transformer to strip compat annotation
+        // ANDROID-BEGIN: b/222743634 Strip annotations from system module stubs
+        if (!stripAnnotationList.isEmpty()) {
+            processors.add(new StripAnnotationsJarTransformer(stripAnnotationList));
+        }
+        // ANDROID-END: b/222743634 Strip annotations from system module stubs
         processors.add(new JarTransformerChain(new RemappingClassTransformer[]{ new RemappingClassTransformer(pr) }));
         processors.add(new ResourceProcessor(pr));
         chain = new JarProcessorChain(processors.toArray(new JarProcessor[processors.size()]));
diff --git a/src/main/com/tonicsystems/jarjar/RulesFileParser.java b/src/main/com/tonicsystems/jarjar/RulesFileParser.java
index f54f3b9..c8c6ea4 100644
--- a/src/main/com/tonicsystems/jarjar/RulesFileParser.java
+++ b/src/main/com/tonicsystems/jarjar/RulesFileParser.java
@@ -16,6 +16,8 @@
 
 package com.tonicsystems.jarjar;
 
+import com.android.jarjar.StripAnnotation;
+
 import java.io.*;
 import java.util.*;
 
@@ -62,6 +64,10 @@ class RulesFileParser
                 element = new Zap();
             } else if (type.equals("keep")) {
                 element = new Keep();
+            // ANDROID-BEGIN: b/222743634 Strip annotations from system module stubs
+            } else if (type.equals("strip-annotation")) {
+                element = new StripAnnotation();
+            // ANDROID-END: b/222743634 Strip annotations from system module stubs
             } else {
                 error(c, parts);
             }