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';

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

 class CBindingGenerator {
   static const _classVarPrefix = '_c';
   static const _methodVarPrefix = '_m';
   static const _fieldVarPrefix = '_f';
   static const _indent = '    ';

   static const _cTypeKeywords = {
     'short',
     'char',
     'int',
     'long',
     'float',
     'double',
   };

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

   CBindingGenerator(this.config);
   Config config;

   String generateBinding(ClassDecl c) {
     return _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 methodVar = '${_methodVarPrefix}_${cClassName}_$name';
     s.write('jmethodID $methodVar = NULL;\n');

     final returnType = isCtor(m) ? 'jobject' : m.returnType.name;
     final cReturnType = cType(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 signature = _signature(m);

     final ifError = '($cReturnType)0';

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

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

     s.write(_initParams(m));

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

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

     final callType = _typeNameAtCallSite(m.returnType);
     final callArgs = _callArgs(m, classVar, methodVar);
     if (isACtor) {
       s.write('(*jniEnv)->NewObject($callArgs);\n');
     } else {
       final ifStatic = isStatic ? 'Static' : '';
       s.write('(*jniEnv)->Call$ifStatic${callType}Method($callArgs);\n');
     }
     s.write(_destroyParams(m));
     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' : cType(f.type.name);
       // Getter
       final prefix = isSetter ? 'set' : 'get';
       s.write('$ct ${prefix}_${memberNameInC(c, fieldName)}(');
       final formalArgs = <String>[
         if (!isStatic) 'jobject self_',
         if (isSetter) '${cType(f.type.name)} value',
       ];
       s.write(formalArgs.join(', '));
       s.write(') {\n');
       s.write(_loadEnvCall);
       s.write(_loadClassCall(classVar, _internalName(c.binaryName), '($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');
       // TODO(#25): Check Exceptions.
       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 = _cParamRename(param.name);
       args.add('${cType(param.type.name)} $paramName');
     }

     return args.join(", ");
   }

   bool _needsTemporaries(String binaryName) {
     // currently no type needs temporaries.
     return false;
   }

   // arguments at call site
   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 = _cParamRename(param.name);
       if (_needsTemporaries(param.type.name)) {
         args.add('_$paramName');
       } else {
         args.add(paramName);
       }
     }
     return args.join(', ');
   }

   String _initParams(Method m) {
     // currently no type needs temporaries, but in future we may add
     // some options that require temporaries.
     return '';
   }

   String _destroyParams(Method m) {
     final s = StringBuffer();
     for (var param in m.params) {
       final paramName = _cParamRename(param.name);
       if (_needsTemporaries(param.type.name)) {
         s.write('$_indent(*jniEnv)->DeleteLocalRef(jniEnv, _$paramName);\n');
       }
     }
     return s.toString();
   }

   String _result(Method m) {
     final cReturnType = cType(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 iname = _internalNameOf(f.type);
     if (iname.length == 1) {
       return iname;
     }
     return 'L$iname;';
   }

   String _internalName(String binaryName) {
     switch (binaryName) {
       case "void":
         return "V";
       case "byte":
         return "B";
       case "char":
         return "C";
       case "double":
         return "D";
       case "float":
         return "F";
       case "int":
         return "I";
       case "long":
         return "J";
       case "short":
         return "S";
       case "boolean":
         return "Z";
       default:
         return binaryName.replaceAll(".", "/");
     }
   }

   String _internalNameOf(TypeUsage usage) {
     switch (usage.kind) {
       case Kind.declared:
         return _internalName((usage.type as DeclaredType).binaryName);
       case Kind.primitive:
         return _internalName((usage.type as PrimitiveType).name);
       case Kind.typeVariable:
         // It should be possible to compute the erasure of a type
         // in parser itself.
         // TODO(#23): Use erasure of the type variable here.
         // This is just a (wrong) placeholder
         return "java/lang/Object";
       case Kind.array:
         final inner = _internalNameOf((usage.type as ArrayType).type);
         return "[$inner";
       case Kind.wildcard:
         final extendsBound = (usage.type as Wildcard).extendsBound;
         if (extendsBound != null) {
           return _internalNameOf(extendsBound);
         }
         return 'java/lang/Object';
     }
   }

   /// Returns the JNI signature of the method.
   String _signature(Method m) {
     final s = StringBuffer();
     s.write('(');
     for (var param in m.params) {
       final type = _internalNameOf(param.type);
       s.write(type.length == 1 ? type : 'L$type;');
     }
     s.write(')');
     final returnType = _internalNameOf(m.returnType);
     s.write(returnType.length == 1 ? returnType : 'L$returnType;');
     return s.toString();
   }

   // For call<type>Method or get<type>field calls in JNI.
   String _typeNameAtCallSite(TypeUsage t) {
     if (isPrimitive(t)) {
       return t.name.substring(0, 1).toUpperCase() + t.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';

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

	class CBindingGenerator {
	static const _classVarPrefix = '_c';
	static const _methodVarPrefix = '_m';
	static const _fieldVarPrefix = '_f';
	static const _indent = ' ';

	static const _cTypeKeywords = {
	'short',
	'char',
	'int',
	'long',
	'float',
	'double',
	};

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

	CBindingGenerator(this.config);
	Config config;

	String generateBinding(ClassDecl c) {
	return _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 methodVar = '${_methodVarPrefix}_${cClassName}_$name';
	s.write('jmethodID $methodVar = NULL;\n');

	final returnType = isCtor(m) ? 'jobject' : m.returnType.name;
	final cReturnType = cType(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 signature = _signature(m);

	final ifError = '($cReturnType)0';

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

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

	s.write(_initParams(m));

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

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

	final callType = _typeNameAtCallSite(m.returnType);
	final callArgs = _callArgs(m, classVar, methodVar);
	if (isACtor) {
	s.write('(*jniEnv)->NewObject($callArgs);\n');
	} else {
	final ifStatic = isStatic ? 'Static' : '';
	s.write('(*jniEnv)->Call$ifStatic${callType}Method($callArgs);\n');
	}
	s.write(_destroyParams(m));
	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' : cType(f.type.name);
	// Getter
	final prefix = isSetter ? 'set' : 'get';
	s.write('$ct ${prefix}_${memberNameInC(c, fieldName)}(');
	final formalArgs = <String>[
	if (!isStatic) 'jobject self_',
	if (isSetter) '${cType(f.type.name)} value',
	];
	s.write(formalArgs.join(', '));
	s.write(') {\n');
	s.write(_loadEnvCall);
	s.write(_loadClassCall(classVar, _internalName(c.binaryName), '($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');
	// TODO(#25): Check Exceptions.
	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 = _cParamRename(param.name);
	args.add('${cType(param.type.name)} $paramName');
	}

	return args.join(", ");
	}

	bool _needsTemporaries(String binaryName) {
	// currently no type needs temporaries.
	return false;
	}

	// arguments at call site
	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 = _cParamRename(param.name);
	if (_needsTemporaries(param.type.name)) {
	args.add('_$paramName');
	} else {
	args.add(paramName);
	}
	}
	return args.join(', ');
	}

	String _initParams(Method m) {
	// currently no type needs temporaries, but in future we may add
	// some options that require temporaries.
	return '';
	}

	String _destroyParams(Method m) {
	final s = StringBuffer();
	for (var param in m.params) {
	final paramName = _cParamRename(param.name);
	if (_needsTemporaries(param.type.name)) {
	s.write('$_indent(*jniEnv)->DeleteLocalRef(jniEnv, _$paramName);\n');
	}
	}
	return s.toString();
	}

	String _result(Method m) {
	final cReturnType = cType(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 iname = _internalNameOf(f.type);
	if (iname.length == 1) {
	return iname;
	}
	return 'L$iname;';
	}

	String _internalName(String binaryName) {
	switch (binaryName) {
	case "void":
	return "V";
	case "byte":
	return "B";
	case "char":
	return "C";
	case "double":
	return "D";
	case "float":
	return "F";
	case "int":
	return "I";
	case "long":
	return "J";
	case "short":
	return "S";
	case "boolean":
	return "Z";
	default:
	return binaryName.replaceAll(".", "/");
	}
	}

	String _internalNameOf(TypeUsage usage) {
	switch (usage.kind) {
	case Kind.declared:
	return _internalName((usage.type as DeclaredType).binaryName);
	case Kind.primitive:
	return _internalName((usage.type as PrimitiveType).name);
	case Kind.typeVariable:
	// It should be possible to compute the erasure of a type
	// in parser itself.
	// TODO(#23): Use erasure of the type variable here.
	// This is just a (wrong) placeholder
	return "java/lang/Object";
	case Kind.array:
	final inner = _internalNameOf((usage.type as ArrayType).type);
	return "[$inner";
	case Kind.wildcard:
	final extendsBound = (usage.type as Wildcard).extendsBound;
	if (extendsBound != null) {
	return _internalNameOf(extendsBound);
	}
	return 'java/lang/Object';
	}
	}

	/// Returns the JNI signature of the method.
	String _signature(Method m) {
	final s = StringBuffer();
	s.write('(');
	for (var param in m.params) {
	final type = _internalNameOf(param.type);
	s.write(type.length == 1 ? type : 'L$type;');
	}
	s.write(')');
	final returnType = _internalNameOf(m.returnType);
	s.write(returnType.length == 1 ? returnType : 'L$returnType;');
	return s.toString();
	}

	// For call<type>Method or get<type>field calls in JNI.
	String _typeNameAtCallSite(TypeUsage t) {
	if (isPrimitive(t)) {
	return t.name.substring(0, 1).toUpperCase() + t.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;
	}