Bug 1378410 - 1. Support BuildFlag annotation for generated bindings;…

… r=snorp Add a BuildFlag annotation, which when specified for classes, will wrap generated code in `#ifdef` or `#ifndef` blocks. This functionality is used for conditionally excluding generated code when NIghtly becomes Beta, without the need to regenerate bindings. MozReview-Commit-ID: L2NFM8CHKqF --HG-- extra : rebase_source : 6ebc82d11fd1aa4aeb57a46262e678480d23de83
dothq · Sep 1, 2017 · f0ca31b · f0ca31b
1 parent b087363
commit f0ca31b
Show file tree

Hide file tree

Showing 9 changed files with 94 additions and 9 deletions.
diff --git a/build/annotationProcessors/AnnotationProcessor.java b/build/annotationProcessors/AnnotationProcessor.java
@@ -29,7 +29,7 @@ public class AnnotationProcessor {
 
     public static void main(String[] args) {
         // We expect a list of jars on the commandline. If missing, whinge about it.
-        if (args.length <= 2) {
+        if (args.length < 2) {
             System.err.println("Usage: java AnnotationProcessor outprefix jarfiles ...");
             System.exit(1);
         }
@@ -56,15 +56,19 @@ public static void main(String[] args) {
                 "#ifndef " + getHeaderGuardName(HEADER_FILE) + "\n" +
                 "#define " + getHeaderGuardName(HEADER_FILE) + "\n" +
                 "\n" +
+                "#ifndef MOZ_PREPROCESSOR\n" +
                 "#include \"mozilla/jni/Refs.h\"\n" +
+                "#endif\n" +
                 "\n" +
                 "namespace mozilla {\n" +
                 "namespace java {\n" +
                 "\n");
 
         implementationFile.append(
+                "#ifndef MOZ_PREPROCESSOR\n" +
                 "#include \"" + HEADER_FILE + "\"\n" +
                 "#include \"mozilla/jni/Accessors.h\"\n" +
+                "#endif\n" +
                 "\n" +
                 "namespace mozilla {\n" +
                 "namespace java {\n" +
@@ -74,8 +78,10 @@ public static void main(String[] args) {
                 "#ifndef " + getHeaderGuardName(NATIVES_FILE) + "\n" +
                 "#define " + getHeaderGuardName(NATIVES_FILE) + "\n" +
                 "\n" +
+                "#ifndef MOZ_PREPROCESSOR\n" +
                 "#include \"" + HEADER_FILE + "\"\n" +
                 "#include \"mozilla/jni/Natives.h\"\n" +
+                "#endif\n" +
                 "\n" +
                 "namespace mozilla {\n" +
                 "namespace java {\n" +

diff --git a/build/annotationProcessors/CodeGenerator.java b/build/annotationProcessors/CodeGenerator.java
@@ -27,6 +27,7 @@ public class CodeGenerator {
 
     private final Class<?> cls;
     private final String clsName;
+    private final ClassWithOptions options;
     private AnnotationInfo.CallingThread callingThread = null;
     private int numNativesInits;
 
@@ -35,9 +36,11 @@ public class CodeGenerator {
     public CodeGenerator(ClassWithOptions annotatedClass) {
         this.cls = annotatedClass.wrappedClass;
         this.clsName = annotatedClass.generatedName;
+        this.options = annotatedClass;
 
         final String unqualifiedName = Utils.getUnqualifiedName(clsName);
         header.append(
+                Utils.getIfdefHeader(annotatedClass.ifdef) +
                 "class " + clsName + " : public mozilla::jni::ObjectBase<" +
                         unqualifiedName + ">\n" +
                 "{\n" +
@@ -49,11 +52,13 @@ public CodeGenerator(ClassWithOptions annotatedClass) {
                 "\n");
 
         cpp.append(
+                Utils.getIfdefHeader(annotatedClass.ifdef) +
                 "const char " + clsName + "::name[] =\n" +
                 "        \"" + cls.getName().replace('.', '/') + "\";\n" +
                 "\n");
 
         natives.append(
+                Utils.getIfdefHeader(annotatedClass.ifdef) +
                 "template<class Impl>\n" +
                 "class " + clsName + "::Natives : " +
                         "public mozilla::jni::NativeImpl<" + unqualifiedName + ", Impl>\n" +
@@ -556,6 +561,8 @@ public void generateClasses(final ClassWithOptions[] classes) {
      * @return The bytes to be written to the wrappers file.
      */
     public String getWrapperFileContents() {
+        cpp.append(
+                Utils.getIfdefFooter(options.ifdef));
         return cpp.toString();
     }
 
@@ -580,7 +587,8 @@ public String getHeaderFileContents() {
         }
         header.append(
                 "};\n" +
-                "\n");
+                "\n" +
+                Utils.getIfdefFooter(options.ifdef));
         return header.toString();
     }
 
@@ -600,7 +608,8 @@ public String getNativesFileContents() {
                 "template<class Impl>\n" +
                 "const JNINativeMethod " + clsName + "::Natives<Impl>::methods[] = {" + nativesInits + '\n' +
                 "};\n" +
-                "\n");
+                "\n" +
+                Utils.getIfdefFooter(options.ifdef));
         return natives.toString();
     }
 }
diff --git a/build/annotationProcessors/SDKProcessor.java b/build/annotationProcessors/SDKProcessor.java
@@ -412,7 +412,8 @@ private static void generateClass(Class<?> clazz,
                                       StringBuilder headerFile) throws ParseException {
         String generatedName = clazz.getSimpleName();
 
-        CodeGenerator generator = new CodeGenerator(new ClassWithOptions(clazz, generatedName));
+        CodeGenerator generator = new CodeGenerator(
+                new ClassWithOptions(clazz, generatedName, /* ifdef */ ""));
 
         generateMembers(generator, clsInfo,
                         sortAndFilterMembers(clazz, clazz.getConstructors()));

diff --git a/build/annotationProcessors/classloader/ClassWithOptions.java b/build/annotationProcessors/classloader/ClassWithOptions.java
@@ -7,9 +7,11 @@
 public class ClassWithOptions {
     public final Class<?> wrappedClass;
     public final String generatedName;
+    public final String ifdef;
 
-    public ClassWithOptions(Class<?> someClass, String name) {
+    public ClassWithOptions(Class<?> someClass, String name, String ifdef) {
         wrappedClass = someClass;
         generatedName = name;
+        this.ifdef = ifdef;
     }
 }
diff --git a/build/annotationProcessors/classloader/JarClassIterator.java b/build/annotationProcessors/classloader/JarClassIterator.java
@@ -4,6 +4,8 @@
 
 package org.mozilla.gecko.annotationProcessors.classloader;
 
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Method;
 import java.util.Iterator;
 
 /**
@@ -67,7 +69,27 @@ private boolean fillLookAheadIfPossible() {
                 return fillLookAheadIfPossible();
             }
 
-            lookAhead = new ClassWithOptions(ret, ret.getSimpleName());
+            String ifdef = "";
+            for (final Annotation annotation : ret.getDeclaredAnnotations()) {
+                Class<? extends Annotation> annotationType = annotation.annotationType();
+                if (!annotationType.getName().equals(
+                        "org.mozilla.gecko.annotation.BuildFlag")) {
+                    continue;
+                }
+
+                try {
+                    final Method valueMethod = annotationType.getDeclaredMethod("value");
+                    valueMethod.setAccessible(true);
+                    ifdef = (String) valueMethod.invoke(annotation);
+                    break;
+                } catch (final Exception e) {
+                    System.err.println("Unable to read BuildFlag annotation.");
+                    e.printStackTrace(System.err);
+                    System.exit(1);
+                }
+            }
+
+            lookAhead = new ClassWithOptions(ret, ret.getSimpleName(), ifdef);
             return true;
         } catch (ClassNotFoundException e) {
             System.err.println("Unable to enumerate class: " + className + ". Corrupted jar file?");

diff --git a/build/annotationProcessors/utils/GeneratableElementIterator.java b/build/annotationProcessors/utils/GeneratableElementIterator.java
@@ -77,8 +77,8 @@ private Class<?>[] getFilteredInnerClasses() {
         int count = 0;
 
         for (int i = 0; i < candidates.length; ++i) {
-            final GeneratableElementIterator testIterator
-                    = new GeneratableElementIterator(new ClassWithOptions(candidates[i], null));
+            final GeneratableElementIterator testIterator = new GeneratableElementIterator(
+                    new ClassWithOptions(candidates[i], null, /* ifdef */ ""));
             if (testIterator.hasNext()
                     || testIterator.getFilteredInnerClasses() != null) {
                 count++;
@@ -108,7 +108,9 @@ public ClassWithOptions[] getInnerClasses() {
         for (Class<?> candidate : candidates) {
             if (candidate != null) {
                 ret[count++] = new ClassWithOptions(
-                        candidate, mClass.generatedName + "::" + candidate.getSimpleName());
+                        candidate,
+                        mClass.generatedName + "::" + candidate.getSimpleName(),
+                        /* ifdef */ "");
             }
         }
         assert ret.length == count;

diff --git a/build/annotationProcessors/utils/Utils.java b/build/annotationProcessors/utils/Utils.java
@@ -327,4 +327,20 @@ public static <T extends Enum<T>> T getEnumValue(Class<T> type, String name) {
             return null;
         }
     }
+
+    public static String getIfdefHeader(String ifdef) {
+        if (ifdef.isEmpty()) {
+            return "";
+        } else if (ifdef.startsWith("!")) {
+            return "#ifndef " + ifdef.substring(1) + "\n";
+        }
+        return "#ifdef " + ifdef + "\n";
+    }
+
+    public static String getIfdefFooter(String ifdef) {
+        if (ifdef.isEmpty()) {
+            return "";
+        }
+        return "#endif // " + ifdef + "\n";
+    }
 }
diff --git a/mobile/android/base/moz.build b/mobile/android/base/moz.build
@@ -148,6 +148,7 @@ thirdparty_source_dir = TOPSRCDIR + '/mobile/android/thirdparty/'
 
 constants_jar = add_java_jar('constants')
 constants_jar.sources += [geckoview_source_dir + 'java/org/mozilla/gecko/' + x for x in [
+    'annotation/BuildFlag.java',
     'annotation/JNITarget.java',
     'annotation/ReflectionTarget.java',
     'annotation/RobocopTarget.java',

diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/annotation/BuildFlag.java b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/annotation/BuildFlag.java
@@ -0,0 +1,26 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * This annotation is used to tag classes that are conditionally built behind
+ * build flags. Any generated JNI bindings will incorporate the specified build
+ * flags.
+ */
+@Target({ElementType.TYPE})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface BuildFlag {
+    /**
+     * Preprocessor macro for conditionally building the generated bindings.
+     * "MOZ_FOO" wraps generated bindings in "#ifdef MOZ_FOO / #endif"
+     * "!MOZ_FOO" wraps generated bindings in "#ifndef MOZ_FOO / #endif"
+     */
+    String value() default "";
+}