MethodMaker [BCEL helper] [1034309]

!include once #1019934 // BCEL

sclass MethodMaker {
  replace Type with org.apache.bcel.generic.Type.
  
  ClassGen cg;
  MethodGen mg;
  new InstructionList il;
  ConstantPoolGen cp;
  InstructionFactory factory;
  int frameSize;
  Type[] argTypes;
  int[] argStackIndex;

  settable bool verboseAdd;
  
  delegate none, objValue, intValue, doubleValue to JVMStackCellType.
  
  bool classConstantWorkaround;
    
  *(ClassMaker classMaker, Class returnType, S methodName, Class... argumentTypes) {
    this(classMaker.cg, returnType, methodName, argumentTypes);
  }
  
  *(ClassGen cg, Class returnType, S methodName, Class... argumentTypes) {
    this(cg, Const.ACC_PUBLIC, returnType, methodName, argumentTypes);
  }
  
  // types: Class or S
  *(ClassGen *cg, short modifiers, O returnType, S methodName, O... argumentTypes) {
    cp = cg.getConstantPool();
    factory = new InstructionFactory(cg);
  
    argTypes = wrapTypes(argumentTypes);
      
    mg = new MethodGen(modifiers,
      wrapType(returnType),
      argTypes, null /* argNames */, methodName, cg.getClassName(), il, cp);
      
    layoutStack();
  }

  *(ClassGen *cg, short modifiers, Class returnType, S methodName, Class... argumentTypes) {
    cp = cg.getConstantPool();
    factory = new InstructionFactory(cg);
  
    argTypes = wrapTypes(argumentTypes);
      
    mg = new MethodGen(modifiers,
      wrapType(returnType),
      argTypes, null /* argNames */, methodName, cg.getClassName(), il, cp);
      
    layoutStack();
  }
  
  void layoutStack {
    frameSize = 1; // assume method is not static
    argStackIndex = new int[l(argTypes)];
    for i over argTypes: {
      argStackIndex[i] = frameSize;
      frameSize += eqOneOf(argTypes[i], Type.LONG, Type.DOUBLE) ? 2 : 1;
    }
  }

  static Type[] wrapTypes(O[] classes) {  
    Type[] types = new[l(classes)];
    for i over classes:
      types[i] = wrapType(classes[i]);
    ret types;
  }
  
  static Type wrapType(O o) {
    if (o cast Class)
      ret classToBCELType(o);
    if (o cast S) {
      Class c = parsePrimitiveType(o);
      if (c != null) ret classToBCELType(c);
      ret new ObjectType(o);
    }
    null;
  }

  // create local variable and return its index
  int newLocalVar() { ret frameSize++; }
  
  selfType newObject(Class c, Class... argTypes) {
    il.append(factory.createNew(className(c)));
    il.append(InstructionConst.DUP);
    invokeConstructor(c, argTypes);
    this;
  }
  
  selfType invokeConstructor(Class c, Class... argTypes) {
    Constructor ctor = findConstructor_precise_onTypes(c, argTypes);
    il.append(factory.createInvoke(className(c), "<init>",
      Type.VOID, wrapTypes(ctor.getParameterTypes()),
      Const.INVOKESPECIAL));
    this;
  }
  
  selfType dup() {
    il.append(InstructionConst.DUP);
    this;
  }
  
  // store object in local variable
  selfType astore(int var) {
    il.append(new ASTORE(var));
    this;
  }
  
  int argIdx(int iArg) {
    ret argStackIndex[iArg];
  }
  
  selfType aloadArgWithAutoboxing(int iArg) {  
    var type = argTypes[iArg];
    int stackIdx = argStackIndex[iArg];

    if (type == Type.BYTE) {
      il.append(new ILOAD(stackIdx));
      invokeStatic(Byte.class, Byte.class, "valueOf", byte.class);
      this;
    }
    
    if (type == Type.BOOLEAN) {
      il.append(new ILOAD(stackIdx));
      invokeStatic(Bool.class, Bool.class, "valueOf", bool.class);
      this;
    }
    
    if (type == Type.CHAR) {
      il.append(new ILOAD(stackIdx));
      invokeStatic(Char.class, Char.class, "valueOf", char.class);
      this;
    }
    
    if (type == Type.SHORT) {
      il.append(new ILOAD(stackIdx));
      invokeStatic(Short.class, Short.class, "valueOf", short.class);
      this;
    }
    
    if (type == Type.INT) {
      il.append(new ILOAD(stackIdx));
      invokeStatic(Int.class, Int.class, "valueOf", int.class);
      this;
    }
    
    if (type == Type.LONG) {
      il.append(new LLOAD(stackIdx));
      invokeStatic(Long.class, Long.class, "valueOf", long.class);
      this;
    }
      
    if (type == Type.FLOAT) {
      il.append(new LLOAD(stackIdx));
      invokeStatic(Float.class, Float.class, "valueOf", float.class);
      this;
    }
      
    if (type == Type.DOUBLE) {
      il.append(new DLOAD(stackIdx));
      invokeStatic(Double.class, Double.class, "valueOf", double.class);
      this;
    }
      
    ret aload(stackIdx);
  }
    
  selfType aload(int stackIdx) {  
    il.append(new ALOAD(stackIdx));
    this;
  }
  
  selfType stringConstant(S s) {
    il.append(new PUSH(cp, s));
    this;
  }
  
  selfType classConstant(Class c) {
    if (classConstantWorkaround) {
      stringConstant(c.getName());
      invokeStatic(Class.class, Class.class, "forName", S);
    } else {
      var ldc = new LDC(classRef(c));
      assertEquals("classConstant", ldc.getValue(cp), wrapType(c));
      il.append(ldc);
    }
    this;
  }
  
  selfType intConstant aka intConst(int i) {
    if (i >= -1 && i <= 5) ret add(new ICONST(i));
    if (i == (byte) i) ret add(new BIPUSH((byte) i));
    if (i == (short) i) ret add(new SIPUSH((short) i));
    ret add(new LDC(cp.addInteger(i)));
  }
  
  selfType doubleConstant aka doubleConst(double d) {
    ret add(new LDC2_W(cp.addDouble(d)));
  }
  
  selfType boolConstant(bool b) {
    ret intConstant(b ? 1 : 0);
  }
  
  selfType invokeVirtual(Class c, Class returnType, S methodName,
    Class... argTypes) {
    Method m = findNonStaticMethod_precise_onTypes(c, methodName, argTypes);
    if (m == null) fail("Method not found: " + className(c) + "."
      + formatFunctionCall(methodName, argTypes) + " returning " + className(returnType));
    il.append(factory.createInvoke(className(c), methodName,
      wrapType(m.getReturnType()),
      wrapTypes(m.getParameterTypes()), Const.INVOKEVIRTUAL));
    this;
  }
    
  selfType invokeInterface(Class c, Class returnType, S methodName,
    Class... argTypes) {
    Method m = mostApplicableMethod_onTypes(
      filter(nonDefaultInterfaceMethods(c), _m -> _m.getName().equals(methodName)),
      argTypes);
    if (m == null) fail("Method not found: " + className(c) + "."
      + formatFunctionCall(methodName, argTypes) + " returning " + className(returnType));
    il.append(factory.createInvoke(className(c), methodName,
      wrapType(m.getReturnType()),
      wrapTypes(m.getParameterTypes()), Const.INVOKEINTERFACE));
    this;
  }
    
  selfType invokeStatic(Class c, Class returnType, S methodName,
    Class... argTypes) {
    Method m = findMethod_precise_onTypes(c, methodName, argTypes);
    if (m == null) fail("Method not found: " + className(c) + "."
      + formatFunctionCall(methodName, argTypes) + " returning " + className(returnType));
    il.append(factory.createInvoke(className(c), methodName,
      wrapType(m.getReturnType()),
      wrapTypes(m.getParameterTypes()), Const.INVOKESTATIC));
    this;
  }
  
  selfType areturn() {
    il.append(InstructionConst.ARETURN);
    this;
  }
  
  selfType _return() {
    il.append(InstructionConst.RETURN);
    this;
  }
  
  selfType returnPrimitive(Class type) {
    il.append(primitiveReturnInstruction(type));
    this;
  }
  
  ReturnInstruction primitiveReturnInstruction(Class type) {
    assertTrue(isPrimitiveType(type));
    
    if (type == long.class) ret InstructionConst.LRETURN;
    if (type == float.class) ret InstructionConst.FRETURN;
    if (type == double.class) ret InstructionConst.DRETURN;
    ret InstructionConst.IRETURN;
  }
  
  meta-for Instruction also as BranchInstruction {
    selfType add(Instruction i) {
      il.append(i);
      if (verboseAdd)
        print("> " + i);
      this;
    }
    
    <A extends Instruction> A addAndReturn(A i) {
      add(i);
      ret i;
    }
  }

  void done() {
    mg.stripAttributes(true);
    mg.setMaxStack();
    mg.setMaxLocals();
    cg.addMethod(mg.getMethod());
  }
  
  JVMStackCellType convertToObject(JVMStackCellType stackTop) {
    if (stackTop == objValue) {}
    else if (stackTop == JVMStackCellType.intValue)
      invokeStatic(Int, Int, "valueOf", int.class);
    else if (stackTop == JVMStackCellType.doubleValue)
      invokeStatic(Double.class, Double.class, "valueOf", double.class);
    else if (stackTop == JVMStackCellType.none)
      add(new ACONST_NULL);
    else
      fail("TODO: add conversion for stack cell type: " + stackTop);
    ret objValue;
  }
  
  void discardStackTop(JVMStackCellType stackTop) {
    if (stackTop == JVMStackCellType.none) {}
    else if (stackTop == JVMStackCellType.doubleValue
      || stackTop == JVMStackCellType.longValue)
      add(new POP2);
    else
      add(new POP);
  }
  
  int classRef(O c) {
    ret cp.addClass((ObjectType) wrapType(assertNotNull(c)));
  }
  
  selfType checkCast(O c) {
    ret add(new CHECKCAST(classRef(c)));
  }

  selfType loadNull() {
    ret add(new ACONST_NULL);
  }
  
  InstructionHandle here() {
    ret il.append(new NOP);
  }
  
  GOTO forwardGoto() {
    ret addAndReturn(new GOTO(null));
  }
  
  void returnWithType(JVMStackCellType stackTop) {
    if (stackTop == JVMStackCellType.objValue)
      areturn();
    else if (stackTop == JVMStackCellType.intValue)
      add(new IRETURN);
    else if (stackTop == JVMStackCellType.doubleValue)
      add(new DRETURN);
    else if (stackTop == JVMStackCellType.none)
      _return();
    else
      fail("TODO: add return for stack cell type: " + stackTop);
  }
  
  void getStaticField(S className, S fieldName, Class type) {
    il.append(factory.createGetStatic(className, fieldName, wrapType(type));
  }
}

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Snippet ID:	#1034309
Snippet name:	MethodMaker [BCEL helper]
Eternal ID of this version:	#1034309/100
Text MD5:	8bc08537462734c591d36bb396d28b74
Transpilation MD5:	bba3e38fc737735f2b3463fe3ac01d01
Author:	stefan
Category:	javax / byte code generation
Type:	JavaX fragment (include)
Public (visible to everyone):	Yes
Archived (hidden from active list):	No
Created/modified:	2022-12-18 03:55:00
Source code size:	9936 bytes / 346 lines
Pitched / IR pitched:	No / No
Views / Downloads:	318 / 880
Version history:	99 change(s)
Referenced in:	[show references]

< > BotCompany Repo | #1034309 // MethodMaker [BCEL helper]

JavaX fragment (include) [tags: use-pretranspiled]

Author comment

1	!include once #1019934 // BCEL
2
3	sclass MethodMaker {
4	replace Type with org.apache.bcel.generic.Type.
5
6	ClassGen cg;
7	MethodGen mg;
8	new InstructionList il;
9	ConstantPoolGen cp;
10	InstructionFactory factory;
11	int frameSize;
12	Type[] argTypes;
13	int[] argStackIndex;
14
15	settable bool verboseAdd;
16
17	delegate none, objValue, intValue, doubleValue to JVMStackCellType.
18
19	bool classConstantWorkaround;
20
21	*(ClassMaker classMaker, Class returnType, S methodName, Class... argumentTypes) {
22	this(classMaker.cg, returnType, methodName, argumentTypes);
23	}
24
25	*(ClassGen cg, Class returnType, S methodName, Class... argumentTypes) {
26	this(cg, Const.ACC_PUBLIC, returnType, methodName, argumentTypes);
27	}
28
29	// types: Class or S
30	(ClassGen cg, short modifiers, O returnType, S methodName, O... argumentTypes) {
31	cp = cg.getConstantPool();
32	factory = new InstructionFactory(cg);
33
34	argTypes = wrapTypes(argumentTypes);
35
36	mg = new MethodGen(modifiers,
37	wrapType(returnType),
38	argTypes, null /* argNames */, methodName, cg.getClassName(), il, cp);
39
40	layoutStack();
41	}
42
43	(ClassGen cg, short modifiers, Class returnType, S methodName, Class... argumentTypes) {
44	cp = cg.getConstantPool();
45	factory = new InstructionFactory(cg);
46
47	argTypes = wrapTypes(argumentTypes);
48
49	mg = new MethodGen(modifiers,
50	wrapType(returnType),
51	argTypes, null /* argNames */, methodName, cg.getClassName(), il, cp);
52
53	layoutStack();
54	}
55
56	void layoutStack {
57	frameSize = 1; // assume method is not static
58	argStackIndex = new int[l(argTypes)];
59	for i over argTypes: {
60	argStackIndex[i] = frameSize;
61	frameSize += eqOneOf(argTypes[i], Type.LONG, Type.DOUBLE) ? 2 : 1;
62	}
63	}
64
65	static Type[] wrapTypes(O[] classes) {
66	Type[] types = new[l(classes)];
67	for i over classes:
68	types[i] = wrapType(classes[i]);
69	ret types;
70	}
71
72	static Type wrapType(O o) {
73	if (o cast Class)
74	ret classToBCELType(o);
75	if (o cast S) {
76	Class c = parsePrimitiveType(o);
77	if (c != null) ret classToBCELType(c);
78	ret new ObjectType(o);
79	}
80	null;
81	}
82
83	// create local variable and return its index
84	int newLocalVar() { ret frameSize++; }
85
86	selfType newObject(Class c, Class... argTypes) {
87	il.append(factory.createNew(className(c)));
88	il.append(InstructionConst.DUP);
89	invokeConstructor(c, argTypes);
90	this;
91	}
92
93	selfType invokeConstructor(Class c, Class... argTypes) {
94	Constructor ctor = findConstructor_precise_onTypes(c, argTypes);
95	il.append(factory.createInvoke(className(c), "<init>",
96	Type.VOID, wrapTypes(ctor.getParameterTypes()),
97	Const.INVOKESPECIAL));
98	this;
99	}
100
101	selfType dup() {
102	il.append(InstructionConst.DUP);
103	this;
104	}
105
106	// store object in local variable
107	selfType astore(int var) {
108	il.append(new ASTORE(var));
109	this;
110	}
111
112	int argIdx(int iArg) {
113	ret argStackIndex[iArg];
114	}
115
116	selfType aloadArgWithAutoboxing(int iArg) {
117	var type = argTypes[iArg];
118	int stackIdx = argStackIndex[iArg];
119
120	if (type == Type.BYTE) {
121	il.append(new ILOAD(stackIdx));
122	invokeStatic(Byte.class, Byte.class, "valueOf", byte.class);
123	this;
124	}
125
126	if (type == Type.BOOLEAN) {
127	il.append(new ILOAD(stackIdx));
128	invokeStatic(Bool.class, Bool.class, "valueOf", bool.class);
129	this;
130	}
131
132	if (type == Type.CHAR) {
133	il.append(new ILOAD(stackIdx));
134	invokeStatic(Char.class, Char.class, "valueOf", char.class);
135	this;
136	}
137
138	if (type == Type.SHORT) {
139	il.append(new ILOAD(stackIdx));
140	invokeStatic(Short.class, Short.class, "valueOf", short.class);
141	this;
142	}
143
144	if (type == Type.INT) {
145	il.append(new ILOAD(stackIdx));
146	invokeStatic(Int.class, Int.class, "valueOf", int.class);
147	this;
148	}
149
150	if (type == Type.LONG) {
151	il.append(new LLOAD(stackIdx));
152	invokeStatic(Long.class, Long.class, "valueOf", long.class);
153	this;
154	}
155
156	if (type == Type.FLOAT) {
157	il.append(new LLOAD(stackIdx));
158	invokeStatic(Float.class, Float.class, "valueOf", float.class);
159	this;
160	}
161
162	if (type == Type.DOUBLE) {
163	il.append(new DLOAD(stackIdx));
164	invokeStatic(Double.class, Double.class, "valueOf", double.class);
165	this;
166	}
167
168	ret aload(stackIdx);
169	}
170
171	selfType aload(int stackIdx) {
172	il.append(new ALOAD(stackIdx));
173	this;
174	}
175
176	selfType stringConstant(S s) {
177	il.append(new PUSH(cp, s));
178	this;
179	}
180
181	selfType classConstant(Class c) {
182	if (classConstantWorkaround) {
183	stringConstant(c.getName());
184	invokeStatic(Class.class, Class.class, "forName", S);
185	} else {
186	var ldc = new LDC(classRef(c));
187	assertEquals("classConstant", ldc.getValue(cp), wrapType(c));
188	il.append(ldc);
189	}
190	this;
191	}
192
193	selfType intConstant aka intConst(int i) {
194	if (i >= -1 && i <= 5) ret add(new ICONST(i));
195	if (i == (byte) i) ret add(new BIPUSH((byte) i));
196	if (i == (short) i) ret add(new SIPUSH((short) i));
197	ret add(new LDC(cp.addInteger(i)));
198	}
199
200	selfType doubleConstant aka doubleConst(double d) {
201	ret add(new LDC2_W(cp.addDouble(d)));
202	}
203
204	selfType boolConstant(bool b) {
205	ret intConstant(b ? 1 : 0);
206	}
207
208	selfType invokeVirtual(Class c, Class returnType, S methodName,
209	Class... argTypes) {
210	Method m = findNonStaticMethod_precise_onTypes(c, methodName, argTypes);
211	if (m == null) fail("Method not found: " + className(c) + "."
212	+ formatFunctionCall(methodName, argTypes) + " returning " + className(returnType));
213	il.append(factory.createInvoke(className(c), methodName,
214	wrapType(m.getReturnType()),
215	wrapTypes(m.getParameterTypes()), Const.INVOKEVIRTUAL));
216	this;
217	}
218
219	selfType invokeInterface(Class c, Class returnType, S methodName,
220	Class... argTypes) {
221	Method m = mostApplicableMethod_onTypes(
222	filter(nonDefaultInterfaceMethods(c), _m -> _m.getName().equals(methodName)),
223	argTypes);
224	if (m == null) fail("Method not found: " + className(c) + "."
225	+ formatFunctionCall(methodName, argTypes) + " returning " + className(returnType));
226	il.append(factory.createInvoke(className(c), methodName,
227	wrapType(m.getReturnType()),
228	wrapTypes(m.getParameterTypes()), Const.INVOKEINTERFACE));
229	this;
230	}
231
232	selfType invokeStatic(Class c, Class returnType, S methodName,
233	Class... argTypes) {
234	Method m = findMethod_precise_onTypes(c, methodName, argTypes);
235	if (m == null) fail("Method not found: " + className(c) + "."
236	+ formatFunctionCall(methodName, argTypes) + " returning " + className(returnType));
237	il.append(factory.createInvoke(className(c), methodName,
238	wrapType(m.getReturnType()),
239	wrapTypes(m.getParameterTypes()), Const.INVOKESTATIC));
240	this;
241	}
242
243	selfType areturn() {
244	il.append(InstructionConst.ARETURN);
245	this;
246	}
247
248	selfType _return() {
249	il.append(InstructionConst.RETURN);
250	this;
251	}
252
253	selfType returnPrimitive(Class type) {
254	il.append(primitiveReturnInstruction(type));
255	this;
256	}
257
258	ReturnInstruction primitiveReturnInstruction(Class type) {
259	assertTrue(isPrimitiveType(type));
260
261	if (type == long.class) ret InstructionConst.LRETURN;
262	if (type == float.class) ret InstructionConst.FRETURN;
263	if (type == double.class) ret InstructionConst.DRETURN;
264	ret InstructionConst.IRETURN;
265	}
266
267	meta-for Instruction also as BranchInstruction {
268	selfType add(Instruction i) {
269	il.append(i);
270	if (verboseAdd)
271	print("> " + i);
272	this;
273	}
274
275	<A extends Instruction> A addAndReturn(A i) {
276	add(i);
277	ret i;
278	}
279	}
280
281	void done() {
282	mg.stripAttributes(true);
283	mg.setMaxStack();
284	mg.setMaxLocals();
285	cg.addMethod(mg.getMethod());
286	}
287
288	JVMStackCellType convertToObject(JVMStackCellType stackTop) {
289	if (stackTop == objValue) {}
290	else if (stackTop == JVMStackCellType.intValue)
291	invokeStatic(Int, Int, "valueOf", int.class);
292	else if (stackTop == JVMStackCellType.doubleValue)
293	invokeStatic(Double.class, Double.class, "valueOf", double.class);
294	else if (stackTop == JVMStackCellType.none)
295	add(new ACONST_NULL);
296	else
297	fail("TODO: add conversion for stack cell type: " + stackTop);
298	ret objValue;
299	}
300
301	void discardStackTop(JVMStackCellType stackTop) {
302	if (stackTop == JVMStackCellType.none) {}
303	else if (stackTop == JVMStackCellType.doubleValue
304	\|\| stackTop == JVMStackCellType.longValue)
305	add(new POP2);
306	else
307	add(new POP);
308	}
309
310	int classRef(O c) {
311	ret cp.addClass((ObjectType) wrapType(assertNotNull(c)));
312	}
313
314	selfType checkCast(O c) {
315	ret add(new CHECKCAST(classRef(c)));
316	}
317
318	selfType loadNull() {
319	ret add(new ACONST_NULL);
320	}
321
322	InstructionHandle here() {
323	ret il.append(new NOP);
324	}
325
326	GOTO forwardGoto() {
327	ret addAndReturn(new GOTO(null));
328	}
329
330	void returnWithType(JVMStackCellType stackTop) {
331	if (stackTop == JVMStackCellType.objValue)
332	areturn();
333	else if (stackTop == JVMStackCellType.intValue)
334	add(new IRETURN);
335	else if (stackTop == JVMStackCellType.doubleValue)
336	add(new DRETURN);
337	else if (stackTop == JVMStackCellType.none)
338	_return();
339	else
340	fail("TODO: add return for stack cell type: " + stackTop);
341	}
342
343	void getStaticField(S className, S fieldName, Class type) {
344	il.append(factory.createGetStatic(className, fieldName, wrapType(type));
345	}
346	}