gecko/build/annotationProcessors/CodeGenerator.java

463 lines
17 KiB
Java

/* 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.annotationProcessors;
import org.mozilla.gecko.annotationProcessors.classloader.AnnotatableEntity;
import org.mozilla.gecko.annotationProcessors.classloader.ClassWithOptions;
import org.mozilla.gecko.annotationProcessors.utils.Utils;
import java.lang.annotation.Annotation;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashSet;
public class CodeGenerator {
private static final Class<?>[] EMPTY_CLASS_ARRAY = new Class<?>[0];
// Buffers holding the strings to ultimately be written to the output files.
private final StringBuilder cpp = new StringBuilder();
private final StringBuilder header = new StringBuilder();
private final Class<?> cls;
private final String clsName;
private final HashSet<String> takenMethodNames = new HashSet<String>();
public CodeGenerator(ClassWithOptions annotatedClass) {
this.cls = annotatedClass.wrappedClass;
this.clsName = annotatedClass.generatedName;
header.append(
"class " + clsName + " : public mozilla::jni::Class<" + clsName + "> {\n" +
"\n" +
"public:\n" +
" typedef mozilla::jni::Ref<" + clsName + "> Ref;\n" +
" typedef mozilla::jni::LocalRef<" + clsName + "> LocalRef;\n" +
" typedef mozilla::jni::GlobalRef<" + clsName + "> GlobalRef;\n" +
" typedef const typename mozilla::jni::Param<" + clsName + ">::Type& Param;\n" +
"\n" +
" static constexpr char name[] =\n" +
" \"" + cls.getName().replace('.', '/') + "\";\n" +
"\n" +
"protected:\n" +
" " + clsName + "(jobject instance) : Class(instance) {}\n" +
"\n");
cpp.append(
"constexpr char " + clsName + "::name[];\n" +
"\n");
}
private String getTraitsName(String uniqueName, boolean includeScope) {
return (includeScope ? clsName + "::" : "") + uniqueName + "_t";
}
private String getNativeParameterType(Class<?> type, AnnotationInfo info) {
if (type == cls) {
return clsName + "::Param";
}
return Utils.getNativeParameterType(type, info);
}
private String getNativeReturnType(Class<?> type, AnnotationInfo info) {
if (type == cls) {
return clsName + "::LocalRef";
}
return Utils.getNativeReturnType(type, info);
}
private void generateMember(AnnotationInfo info, Member member,
String uniqueName, Class<?> type) {
header.append(
"public:\n" +
" struct " + getTraitsName(uniqueName, /* includeScope */ false) + " {\n" +
" typedef " + clsName + " Owner;\n" +
" typedef " + getNativeReturnType(type, info) + " ReturnType;\n" +
" typedef " + getNativeParameterType(type, info) + " SetterType;\n" +
" static constexpr char name[] = \"" +
Utils.getMemberName(member) + "\";\n" +
" static constexpr char signature[] =\n" +
" \"" + Utils.getSignature(member) + "\";\n" +
" static const bool isStatic = " + Utils.isStatic(member) + ";\n" +
" static const bool isMultithreaded = " + info.isMultithreaded + ";\n" +
" static const mozilla::jni::ExceptionMode exceptionMode = " + (
info.catchException ? "mozilla::jni::ExceptionMode::NSRESULT" :
info.noThrow ? "mozilla::jni::ExceptionMode::IGNORE" :
"mozilla::jni::ExceptionMode::ABORT") + ";\n" +
" };\n" +
"\n");
cpp.append(
"constexpr char " + getTraitsName(uniqueName, /* includeScope */ true) +
"::name[];\n" +
"constexpr char " + getTraitsName(uniqueName, /* includeScope */ true) +
"::signature[];\n" +
"\n");
}
private String getUniqueMethodName(String basename) {
String newName = basename;
int index = 1;
while (takenMethodNames.contains(newName)) {
newName = basename + (++index);
}
takenMethodNames.add(newName);
return newName;
}
/**
* Generate a method prototype that includes return and argument types,
* without specifiers (static, const, etc.).
*/
private String generatePrototype(String name, Class<?>[] argTypes,
Class<?> returnType, AnnotationInfo info,
boolean includeScope, boolean includeArgName) {
final StringBuilder proto = new StringBuilder();
int argIndex = 0;
if (info.catchException) {
proto.append("nsresult ");
} else {
proto.append(getNativeReturnType(returnType, info)).append(' ');
}
if (includeScope) {
proto.append(clsName).append("::");
}
proto.append(name).append('(');
for (Class<?> argType : argTypes) {
proto.append(getNativeParameterType(argType, info));
if (includeArgName) {
proto.append(" a").append(argIndex++);
}
proto.append(", ");
}
if (info.catchException && returnType != void.class) {
proto.append(getNativeReturnType(returnType, info)).append('*');
if (includeArgName) {
proto.append(" a").append(argIndex++);
}
proto.append(", ");
}
if (proto.substring(proto.length() - 2).equals(", ")) {
proto.setLength(proto.length() - 2);
}
return proto.append(')').toString();
}
/**
* Generate a method declaration that includes the prototype with specifiers,
* but without the method body.
*/
private String generateDeclaration(String name, Class<?>[] argTypes,
Class<?> returnType, AnnotationInfo info,
boolean isStatic) {
return (isStatic ? "static " : "") +
generatePrototype(name, argTypes, returnType, info,
/* includeScope */ false, /* includeArgName */ false) +
(isStatic ? ";" : " const;");
}
/**
* Generate a method definition that includes the prototype with specifiers,
* and with the method body.
*/
private String generateDefinition(String accessorName, String name, Class<?>[] argTypes,
Class<?> returnType, AnnotationInfo info, boolean isStatic) {
final StringBuilder def = new StringBuilder(
generatePrototype(name, argTypes, returnType, info,
/* includeScope */ true, /* includeArgName */ true));
if (!isStatic) {
def.append(" const");
}
def.append("\n{\n");
// Generate code to handle the return value, if needed.
// We initialize rv to NS_OK instead of NS_ERROR_* because loading NS_OK (0) uses
// fewer instructions. We are guaranteed to set rv to the correct value later.
if (info.catchException && returnType == void.class) {
def.append(
" nsresult rv = NS_OK;\n" +
" ");
} else if (info.catchException) {
// Non-void return type
final String resultArg = "a" + argTypes.length;
def.append(
" MOZ_ASSERT(" + resultArg + ");\n" +
" nsresult rv = NS_OK;\n" +
" *" + resultArg + " = ");
} else {
def.append(
" return ");
}
// Generate a call, e.g., Method<Traits>::Call(a0, a1, a2);
def.append(accessorName).append("(")
.append(isStatic ? "nullptr" : "this");
if (info.catchException) {
def.append(", &rv");
} else {
def.append(", nullptr");
}
// Generate the call argument list.
for (int argIndex = 0; argIndex < argTypes.length; argIndex++) {
def.append(", a").append(argIndex);
}
def.append(");\n");
if (info.catchException) {
def.append(" return rv;\n");
}
return def.append("}").toString();
}
/**
* Append the appropriate generated code to the buffers for the method provided.
*
* @param annotatedMethod The Java method, plus annotation data.
*/
public void generateMethod(AnnotatableEntity annotatedMethod) {
// Unpack the tuple and extract some useful fields from the Method..
final Method method = annotatedMethod.getMethod();
final AnnotationInfo info = annotatedMethod.mAnnotationInfo;
final String uniqueName = getUniqueMethodName(info.wrapperName);
final Class<?> returnType = method.getReturnType();
if (method.isSynthetic()) {
return;
}
generateMember(info, method, uniqueName, returnType);
final Class<?>[] argTypes = method.getParameterTypes();
final boolean isStatic = Utils.isStatic(method);
header.append(
" " + generateDeclaration(info.wrapperName, argTypes,
returnType, info, isStatic) + "\n" +
"\n");
cpp.append(
generateDefinition(
"mozilla::jni::Method<" +
getTraitsName(uniqueName, /* includeScope */ false) + ">::Call",
info.wrapperName, argTypes, returnType, info, isStatic) + "\n" +
"\n");
}
private String getLiteral(Object val, AnnotationInfo info) {
final Class<?> type = val.getClass();
if (type == char.class || type == Character.class) {
final char c = (char) val;
if (c >= 0x20 && c < 0x7F) {
return "'" + c + '\'';
}
return "u'\\u" + Integer.toHexString(0x10000 | (int) c).substring(1) + '\'';
} else if (type == CharSequence.class || type == String.class) {
final CharSequence str = (CharSequence) val;
final StringBuilder out = new StringBuilder(info.narrowChars ? "u8\"" : "u\"");
for (int i = 0; i < str.length(); i++) {
final char c = str.charAt(i);
if (c >= 0x20 && c < 0x7F) {
out.append(c);
} else {
out.append("\\u").append(Integer.toHexString(0x10000 | (int) c).substring(1));
}
}
return out.append('"').toString();
}
return String.valueOf(val);
}
public void generateField(AnnotatableEntity annotatedField) {
final Field field = annotatedField.getField();
final AnnotationInfo info = annotatedField.mAnnotationInfo;
final String uniqueName = info.wrapperName;
final Class<?> type = field.getType();
// Handles a peculiar case when dealing with enum types. We don't care about this field.
// It just gets in the way and stops our code from compiling.
if (field.isSynthetic() || field.getName().equals("$VALUES")) {
return;
}
final boolean isStatic = Utils.isStatic(field);
final boolean isFinal = Utils.isFinal(field);
if (isStatic && isFinal && (type.isPrimitive() || type == String.class)) {
Object val = null;
try {
val = field.get(null);
} catch (final IllegalAccessException e) {
}
if (val != null && type.isPrimitive()) {
// For static final primitive fields, we can use a "static const" declaration.
header.append(
"public:\n" +
" static const " + Utils.getNativeReturnType(type, info) +
' ' + info.wrapperName + " = " + getLiteral(val, info) + ";\n" +
"\n");
return;
} else if (val != null && type == String.class) {
final String nativeType = info.narrowChars ? "char" : "char16_t";
header.append(
"public:\n" +
" static const " + nativeType + ' ' + info.wrapperName + "[];\n" +
"\n");
cpp.append(
"const " + nativeType + ' ' + clsName + "::" + info.wrapperName +
"[] = " + getLiteral(val, info) + ";\n" +
"\n");
return;
}
// Fall back to using accessors if we encounter an exception.
}
generateMember(info, field, uniqueName, type);
final Class<?>[] getterArgs = EMPTY_CLASS_ARRAY;
header.append(
" " + generateDeclaration(info.wrapperName, getterArgs,
type, info, isStatic) + "\n" +
"\n");
cpp.append(
generateDefinition(
"mozilla::jni::Field<" +
getTraitsName(uniqueName, /* includeScope */ false) + ">::Get",
info.wrapperName, getterArgs, type, info, isStatic) + "\n" +
"\n");
if (isFinal) {
return;
}
final Class<?>[] setterArgs = new Class<?>[] { type };
header.append(
" " + generateDeclaration(info.wrapperName, setterArgs,
void.class, info, isStatic) + "\n" +
"\n");
cpp.append(
generateDefinition(
"mozilla::jni::Field<" +
getTraitsName(uniqueName, /* includeScope */ false) + ">::Set",
info.wrapperName, setterArgs, void.class, info, isStatic) + "\n" +
"\n");
}
public void generateConstructor(AnnotatableEntity annotatedConstructor) {
// Unpack the tuple and extract some useful fields from the Method..
final Constructor<?> method = annotatedConstructor.getConstructor();
final AnnotationInfo info = annotatedConstructor.mAnnotationInfo;
final String wrapperName = "New";
final String uniqueName = getUniqueMethodName(wrapperName);
final Class<?> returnType = cls;
if (method.isSynthetic()) {
return;
}
generateMember(info, method, uniqueName, returnType);
final Class<?>[] argTypes = method.getParameterTypes();
header.append(
" " + generateDeclaration(wrapperName, argTypes,
returnType, info, /* isStatic */ true) + "\n" +
"\n");
cpp.append(
generateDefinition(
"mozilla::jni::Constructor<" +
getTraitsName(uniqueName, /* includeScope */ false) + ">::Call",
wrapperName, argTypes, returnType, info, /* isStatic */ true) + "\n" +
"\n");
}
public void generateMembers(Member[] members) {
for (Member m : members) {
if (!Modifier.isPublic(m.getModifiers())) {
continue;
}
String name = Utils.getMemberName(m);
name = name.substring(0, 1).toUpperCase() + name.substring(1);
final AnnotationInfo info = new AnnotationInfo(name,
/* multithread */ true, /* nothrow */ false,
/* narrow */ false, /* catchException */ true);
final AnnotatableEntity entity = new AnnotatableEntity(m, info);
if (m instanceof Constructor) {
generateConstructor(entity);
} else if (m instanceof Method) {
generateMethod(entity);
} else if (m instanceof Field) {
generateField(entity);
} else {
throw new IllegalArgumentException(
"expected member to be Constructor, Method, or Field");
}
}
}
/**
* Get the finalised bytes to go into the generated wrappers file.
*
* @return The bytes to be written to the wrappers file.
*/
public String getWrapperFileContents() {
return cpp.toString();
}
/**
* Get the finalised bytes to go into the generated header file.
*
* @return The bytes to be written to the header file.
*/
public String getHeaderFileContents() {
header.append(
"};\n" +
"\n");
return header.toString();
}
}