pkgs/jnigen/lib/src/bindings/c_bindings.dart - native.git - Git at Google

 // Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 import 'package:jnigen/src/elements/elements.dart';
 import 'package:jnigen/src/config/config.dart';

 import 'common.dart';

 // TODO(#52): Do not use long names in C bindings. Use conflict-renamed short
 // name as class name; Use `__` between class & method name.

 // fullName / mangled name =
 // binaryName with replace('.', '_'), replace('$', '__');

 class CBindingGenerator {
   static const _classVarPrefix = '_c';
   static const _methodVarPrefix = '_m';
   static const _fieldVarPrefix = '_f';
   static final indent = ' ' * 4;

   // These should be avoided in parameter names.
   static const _cTypeKeywords = {
     'short',
     'char',
     'int',
     'long',
     'float',
     'double',
   };

   String _renameCParam(String paramName) =>
       _cTypeKeywords.contains(paramName) ? '${paramName}0' : paramName;

   CBindingGenerator(this.config);
   Config config;

   String generateBinding(ClassDecl c) => _class(c);

   String _class(ClassDecl c) {
     final s = StringBuffer();
     final fullName = mangledClassName(c);

     // global variable in C that holds the reference to class
     final classVar = '${_classVarPrefix}_$fullName';
     s.write('// ${c.binaryName}\n');
     s.write('jclass $classVar = NULL;\n\n');

     for (var m in c.methods) {
       if (!m.isIncluded) {
         continue;
       }
       s.write(_method(c, m));
       s.writeln();
     }

     for (var f in c.fields) {
       if (!f.isIncluded) {
         continue;
       }
       final fieldBinding = _field(c, f);
       s.write(fieldBinding);
       // Fields are skipped if they're static final. In that case
       // do not write too much whitespace.
       if (fieldBinding.isNotEmpty) s.writeln();
     }
     return s.toString();
   }

   String _method(ClassDecl c, Method m) {
     final cClassName = mangledClassName(c);
     final isACtor = isCtor(m);
     final isStatic = isStaticMethod(m);

     final s = StringBuffer();
     final name = m.finalName;

     final methodID = '${_methodVarPrefix}_${cClassName}_$name';
     s.write('jmethodID $methodID = NULL;\n');

     final returnType = isCtor(m) ? 'jobject' : m.returnType.name;
     final cReturnType = getCType(returnType);
     final cMethodName = '${cClassName}_$name';
     final cParams = _formalArgs(m);
     s.write('FFI_PLUGIN_EXPORT\n');
     s.write('$cReturnType $cMethodName($cParams) {\n');

     final classVar = '${_classVarPrefix}_$cClassName';
     final jniSignature = getJniSignature(m);

     final ifError = '($cReturnType)0';

     s.write(_loadEnvCall);
     s.write(_loadClassCall(classVar, getInternalName(c.binaryName), ifError));

     final ifStatic = isStatic ? 'static_' : '';
     s.write('${indent}load_${ifStatic}method($classVar, '
         '&$methodID, "${m.name}", "$jniSignature");\n');
     s.write('${indent}if ($methodID == NULL) return $ifError;\n');

     var returnTypeName = m.returnType.name;
     if (isACtor) {
       returnTypeName = c.binaryName;
     }

     s.write(indent);
     if (returnTypeName != 'void') {
       s.write('${getCType(returnTypeName)} _result = ');
     }

     final callType = _typeNameAtCallSite(m.returnType);
     final callArgs = _callArgs(m, classVar, methodID);
     if (isACtor) {
       s.write('(*jniEnv)->NewObject($callArgs);\n');
     } else {
       final ifStatic = isStatic ? 'Static' : '';
       s.write('(*jniEnv)->Call$ifStatic${callType}Method($callArgs);\n');
     }
     if (returnTypeName != 'void') {
       s.write(_result(m));
     }
     s.write('}\n');
     return s.toString();
   }

   String _field(ClassDecl c, Field f) {
     final cClassName = mangledClassName(c);
     final isStatic = isStaticField(f);

     // If the field is final and default is assigned, then no need to wrap
     // this field. It should then be a constant in dart code.
     if (isStatic && isFinalField(f) && f.defaultValue != null) {
       return "";
     }

     final s = StringBuffer();

     final fieldName = f.finalName;
     final fieldVar = "${_fieldVarPrefix}_${cClassName}_$fieldName";

     s.write('jfieldID $fieldVar = NULL;\n');
     final classVar = '${_classVarPrefix}_$cClassName';

     void writeAccessor({bool isSetter = false}) {
       final ct = isSetter ? 'void' : getCType(f.type.name);
       // Getter
       final prefix = isSetter ? 'set' : 'get';
       s.write('FFI_PLUGIN_EXPORT\n');
       s.write('$ct ${prefix}_${memberNameInC(c, fieldName)}(');
       final formalArgs = <String>[
         if (!isStatic) 'jobject self_',
         if (isSetter) '${getCType(f.type.name)} value',
       ];
       s.write(formalArgs.join(', '));
       s.write(') {\n');
       s.write(_loadEnvCall);
       s.write(
           _loadClassCall(classVar, getInternalName(c.binaryName), '($ct)0'));

       var ifStatic = isStatic ? 'static_' : '';
       s.write(
           '${indent}load_${ifStatic}field($classVar, &$fieldVar, "$fieldName",'
           '"${_fieldSignature(f)}");\n');

       ifStatic = isStatic ? 'Static' : '';
       final callType = _typeNameAtCallSite(f.type);
       final acc = isSetter ? 'Set' : 'Get';
       final ret = isSetter ? '' : 'return ';
       final conv = !isSetter && !isPrimitive(f.type) ? 'to_global_ref' : '';
       s.write('$indent$ret$conv((*jniEnv)->$acc$ifStatic${callType}Field');
       final secondArg = isStatic ? classVar : 'self_';
       s.write('(jniEnv, $secondArg, $fieldVar');
       if (isSetter) {
         s.write(', value');
       }
       s.write('));\n');
       s.write('}\n\n');
     }

     writeAccessor(isSetter: false);
     if (isFinalField(f)) {
       return s.toString();
     }
     writeAccessor(isSetter: true);
     return s.toString();
   }

   final String _loadEnvCall = '${indent}load_env();\n';

   String _loadClassCall(String classVar, String internalName, String ifError) {
     return '${indent}load_class_gr(&$classVar, '
         '"$internalName");\n'
         '${indent}if ($classVar == NULL) return $ifError;\n';
   }

   String _formalArgs(Method m) {
     final args = <String>[];
     if (hasSelfParam(m)) {
       // The underscore-suffixed name prevents accidental collision with
       // parameter named self, if any.
       args.add('jobject self_');
     }

     for (var param in m.params) {
       final paramName = _renameCParam(param.name);
       args.add('${getCType(param.type.name)} $paramName');
     }

     return args.join(", ");
   }

   // Returns arguments at call site, concatenated by `,`.
   String _callArgs(Method m, String classVar, String methodVar) {
     final args = ['jniEnv'];
     if (hasSelfParam(m)) {
       args.add('self_');
     } else {
       args.add(classVar);
     }
     args.add(methodVar);
     for (var param in m.params) {
       final paramName = _renameCParam(param.name);
       args.add(paramName);
     }
     return args.join(', ');
   }

   String _result(Method m) {
     final cReturnType = getCType(m.returnType.name);
     if (cReturnType == 'jobject' || isCtor(m)) {
       return '${indent}return to_global_ref(_result);\n';
     } else {
       return '${indent}return _result;\n';
     }
   }

   String _fieldSignature(Field f) {
     final internalName = getInternalNameOfUsage(f.type);
     if (internalName.length == 1) {
       return internalName;
     }
     return 'L$internalName;';
   }

   /// Returns capitalized java type name to be used as in call${type}Method
   /// or get${type}Field etc..
   String _typeNameAtCallSite(TypeUsage type) {
     if (isPrimitive(type)) {
       return type.name.substring(0, 1).toUpperCase() + type.name.substring(1);
     }
     return "Object";
   }
 }

 class CPreludes {
   static const autoGeneratedNotice = '// Autogenerated by jnigen. '
       'DO NOT EDIT!\n\n';
   static const includes = '#include <stdint.h>\n'
       '#include "jni.h"\n'
       '#include "dartjni.h"\n'
       '\n';
   static const defines = 'thread_local JNIEnv *jniEnv;\n'
       'JniContext jni;\n\n'
       'JniContext (*context_getter)(void);\n'
       'JNIEnv *(*env_getter)(void);\n'
       '\n';
   static const initializers = 'void setJniGetters(JniContext (*cg)(void),\n'
       '        JNIEnv *(*eg)(void)) {\n'
       '    context_getter = cg;\n'
       '    env_getter = eg;\n'
       '}\n'
       '\n';
   static const prelude =
       autoGeneratedNotice + includes + defines + initializers;
 }
	// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	import 'package:jnigen/src/elements/elements.dart';
	import 'package:jnigen/src/config/config.dart';

	import 'common.dart';

	// TODO(#52): Do not use long names in C bindings. Use conflict-renamed short
	// name as class name; Use `__` between class & method name.

	// fullName / mangled name =
	// binaryName with replace('.', '_'), replace('$', '__');

	class CBindingGenerator {
	static const _classVarPrefix = '_c';
	static const _methodVarPrefix = '_m';
	static const _fieldVarPrefix = '_f';
	static final indent = ' ' * 4;

	// These should be avoided in parameter names.
	static const _cTypeKeywords = {
	'short',
	'char',
	'int',
	'long',
	'float',
	'double',
	};

	String _renameCParam(String paramName) =>
	_cTypeKeywords.contains(paramName) ? '${paramName}0' : paramName;

	CBindingGenerator(this.config);
	Config config;

	String generateBinding(ClassDecl c) => _class(c);

	String _class(ClassDecl c) {
	final s = StringBuffer();
	final fullName = mangledClassName(c);

	// global variable in C that holds the reference to class
	final classVar = '${_classVarPrefix}_$fullName';
	s.write('// ${c.binaryName}\n');
	s.write('jclass $classVar = NULL;\n\n');

	for (var m in c.methods) {
	if (!m.isIncluded) {
	continue;
	}
	s.write(_method(c, m));
	s.writeln();
	}

	for (var f in c.fields) {
	if (!f.isIncluded) {
	continue;
	}
	final fieldBinding = _field(c, f);
	s.write(fieldBinding);
	// Fields are skipped if they're static final. In that case
	// do not write too much whitespace.
	if (fieldBinding.isNotEmpty) s.writeln();
	}
	return s.toString();
	}

	String _method(ClassDecl c, Method m) {
	final cClassName = mangledClassName(c);
	final isACtor = isCtor(m);
	final isStatic = isStaticMethod(m);

	final s = StringBuffer();
	final name = m.finalName;

	final methodID = '${_methodVarPrefix}_${cClassName}_$name';
	s.write('jmethodID $methodID = NULL;\n');

	final returnType = isCtor(m) ? 'jobject' : m.returnType.name;
	final cReturnType = getCType(returnType);
	final cMethodName = '${cClassName}_$name';
	final cParams = _formalArgs(m);
	s.write('FFI_PLUGIN_EXPORT\n');
	s.write('$cReturnType $cMethodName($cParams) {\n');

	final classVar = '${_classVarPrefix}_$cClassName';
	final jniSignature = getJniSignature(m);

	final ifError = '($cReturnType)0';

	s.write(_loadEnvCall);
	s.write(_loadClassCall(classVar, getInternalName(c.binaryName), ifError));

	final ifStatic = isStatic ? 'static_' : '';
	s.write('${indent}load_${ifStatic}method($classVar, '
	'&$methodID, "${m.name}", "$jniSignature");\n');
	s.write('${indent}if ($methodID == NULL) return $ifError;\n');

	var returnTypeName = m.returnType.name;
	if (isACtor) {
	returnTypeName = c.binaryName;
	}

	s.write(indent);
	if (returnTypeName != 'void') {
	s.write('${getCType(returnTypeName)} _result = ');
	}

	final callType = _typeNameAtCallSite(m.returnType);
	final callArgs = _callArgs(m, classVar, methodID);
	if (isACtor) {
	s.write('(*jniEnv)->NewObject($callArgs);\n');
	} else {
	final ifStatic = isStatic ? 'Static' : '';
	s.write('(*jniEnv)->Call$ifStatic${callType}Method($callArgs);\n');
	}
	if (returnTypeName != 'void') {
	s.write(_result(m));
	}
	s.write('}\n');
	return s.toString();
	}

	String _field(ClassDecl c, Field f) {
	final cClassName = mangledClassName(c);
	final isStatic = isStaticField(f);

	// If the field is final and default is assigned, then no need to wrap
	// this field. It should then be a constant in dart code.
	if (isStatic && isFinalField(f) && f.defaultValue != null) {
	return "";
	}

	final s = StringBuffer();

	final fieldName = f.finalName;
	final fieldVar = "${_fieldVarPrefix}_${cClassName}_$fieldName";

	s.write('jfieldID $fieldVar = NULL;\n');
	final classVar = '${_classVarPrefix}_$cClassName';

	void writeAccessor({bool isSetter = false}) {
	final ct = isSetter ? 'void' : getCType(f.type.name);
	// Getter
	final prefix = isSetter ? 'set' : 'get';
	s.write('FFI_PLUGIN_EXPORT\n');
	s.write('$ct ${prefix}_${memberNameInC(c, fieldName)}(');
	final formalArgs = <String>[
	if (!isStatic) 'jobject self_',
	if (isSetter) '${getCType(f.type.name)} value',
	];
	s.write(formalArgs.join(', '));
	s.write(') {\n');
	s.write(_loadEnvCall);
	s.write(
	_loadClassCall(classVar, getInternalName(c.binaryName), '($ct)0'));

	var ifStatic = isStatic ? 'static_' : '';
	s.write(
	'${indent}load_${ifStatic}field($classVar, &$fieldVar, "$fieldName",'
	'"${_fieldSignature(f)}");\n');

	ifStatic = isStatic ? 'Static' : '';
	final callType = _typeNameAtCallSite(f.type);
	final acc = isSetter ? 'Set' : 'Get';
	final ret = isSetter ? '' : 'return ';
	final conv = !isSetter && !isPrimitive(f.type) ? 'to_global_ref' : '';
	s.write('$indent$ret$conv((*jniEnv)->$acc$ifStatic${callType}Field');
	final secondArg = isStatic ? classVar : 'self_';
	s.write('(jniEnv, $secondArg, $fieldVar');
	if (isSetter) {
	s.write(', value');
	}
	s.write('));\n');
	s.write('}\n\n');
	}

	writeAccessor(isSetter: false);
	if (isFinalField(f)) {
	return s.toString();
	}
	writeAccessor(isSetter: true);
	return s.toString();
	}

	final String _loadEnvCall = '${indent}load_env();\n';

	String _loadClassCall(String classVar, String internalName, String ifError) {
	return '${indent}load_class_gr(&$classVar, '
	'"$internalName");\n'
	'${indent}if ($classVar == NULL) return $ifError;\n';
	}

	String _formalArgs(Method m) {
	final args = <String>[];
	if (hasSelfParam(m)) {
	// The underscore-suffixed name prevents accidental collision with
	// parameter named self, if any.
	args.add('jobject self_');
	}

	for (var param in m.params) {
	final paramName = _renameCParam(param.name);
	args.add('${getCType(param.type.name)} $paramName');
	}

	return args.join(", ");
	}

	// Returns arguments at call site, concatenated by `,`.
	String _callArgs(Method m, String classVar, String methodVar) {
	final args = ['jniEnv'];
	if (hasSelfParam(m)) {
	args.add('self_');
	} else {
	args.add(classVar);
	}
	args.add(methodVar);
	for (var param in m.params) {
	final paramName = _renameCParam(param.name);
	args.add(paramName);
	}
	return args.join(', ');
	}

	String _result(Method m) {
	final cReturnType = getCType(m.returnType.name);
	if (cReturnType == 'jobject' \|\| isCtor(m)) {
	return '${indent}return to_global_ref(_result);\n';
	} else {
	return '${indent}return _result;\n';
	}
	}

	String _fieldSignature(Field f) {
	final internalName = getInternalNameOfUsage(f.type);
	if (internalName.length == 1) {
	return internalName;
	}
	return 'L$internalName;';
	}

	/// Returns capitalized java type name to be used as in call${type}Method
	/// or get${type}Field etc..
	String _typeNameAtCallSite(TypeUsage type) {
	if (isPrimitive(type)) {
	return type.name.substring(0, 1).toUpperCase() + type.name.substring(1);
	}
	return "Object";
	}
	}

	class CPreludes {
	static const autoGeneratedNotice = '// Autogenerated by jnigen. '
	'DO NOT EDIT!\n\n';
	static const includes = '#include <stdint.h>\n'
	'#include "jni.h"\n'
	'#include "dartjni.h"\n'
	'\n';
	static const defines = 'thread_local JNIEnv *jniEnv;\n'
	'JniContext jni;\n\n'
	'JniContext (*context_getter)(void);\n'
	'JNIEnv (env_getter)(void);\n'
	'\n';
	static const initializers = 'void setJniGetters(JniContext (*cg)(void),\n'
	' JNIEnv (eg)(void)) {\n'
	' context_getter = cg;\n'
	' env_getter = eg;\n'
	'}\n'
	'\n';
	static const prelude =
	autoGeneratedNotice + includes + defines + initializers;
	}