1 /*
2 * Copyright (c) 2003, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.tools.javac.comp;
27
28 import java.util.EnumSet;
29 import java.util.Set;
30
31 import com.sun.tools.javac.code.*;
32 import com.sun.tools.javac.code.Scope.WriteableScope;
33 import com.sun.tools.javac.tree.*;
34 import com.sun.tools.javac.util.*;
35 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
36 import com.sun.tools.javac.util.JCDiagnostic.Error;
37 import com.sun.tools.javac.code.Source.Feature;
38
39 import com.sun.tools.javac.code.Symbol.*;
40 import com.sun.tools.javac.code.Type.*;
41 import com.sun.tools.javac.resources.CompilerProperties.Errors;
42 import com.sun.tools.javac.tree.JCTree.*;
43
44 import static com.sun.tools.javac.code.Flags.*;
45 import static com.sun.tools.javac.code.Kinds.*;
46 import static com.sun.tools.javac.code.Kinds.Kind.*;
47 import static com.sun.tools.javac.code.TypeTag.TYPEVAR;
48
49 /** Resolves field, method and constructor header, and constructs corresponding Symbols.
50 *
51 * <p><b>This is NOT part of any supported API.
52 * If you write code that depends on this, you do so at your own risk.
53 * This code and its internal interfaces are subject to change or
54 * deletion without notice.</b>
55 */
56 public class MemberEnter extends JCTree.Visitor {
57 protected static final Context.Key<MemberEnter> memberEnterKey = new Context.Key<>();
58
59 /** The Source language setting. */
60 private final Source source;
61 private final Enter enter;
62 private final Log log;
63 private final Check chk;
64 private final Attr attr;
65 private final Symtab syms;
66 private final Annotate annotate;
67 private final Types types;
68 private final Names names;
69 private final DeferredLintHandler deferredLintHandler;
70
71 public static MemberEnter instance(Context context) {
72 MemberEnter instance = context.get(memberEnterKey);
73 if (instance == null)
74 instance = new MemberEnter(context);
75 return instance;
76 }
77
78 @SuppressWarnings("this-escape")
79 protected MemberEnter(Context context) {
80 context.put(memberEnterKey, this);
81 enter = Enter.instance(context);
82 log = Log.instance(context);
83 chk = Check.instance(context);
84 attr = Attr.instance(context);
85 syms = Symtab.instance(context);
86 annotate = Annotate.instance(context);
87 types = Types.instance(context);
88 source = Source.instance(context);
89 names = Names.instance(context);
90 deferredLintHandler = DeferredLintHandler.instance(context);
91 }
92
93 /** Construct method type from method signature.
94 * @param typarams The method's type parameters.
95 * @param params The method's value parameters.
96 * @param res The method's result type,
97 * null if it is a constructor.
98 * @param recvparam The method's receiver parameter,
99 * null if none given; TODO: or already set here?
100 * @param thrown The method's thrown exceptions.
101 * @param env The method's (local) environment.
102 */
103 Type signature(MethodSymbol msym,
104 List<JCTypeParameter> typarams,
105 List<JCVariableDecl> params,
106 JCTree res,
107 JCVariableDecl recvparam,
108 List<JCExpression> thrown,
109 Env<AttrContext> env) {
110
111 // Enter and attribute type parameters.
112 List<Type> tvars = enter.classEnter(typarams, env);
113 attr.attribTypeVariables(typarams, env, true);
114
115 // Enter and attribute value parameters.
116 ListBuffer<Type> argbuf = new ListBuffer<>();
117 for (List<JCVariableDecl> l = params; l.nonEmpty(); l = l.tail) {
118 memberEnter(l.head, env);
119 argbuf.append(l.head.vartype.type);
120 }
121
122 // Attribute result type, if one is given.
123 Type restype = res == null ? syms.voidType : attr.attribType(res, env);
124
125 // Attribute receiver type, if one is given.
126 Type recvtype;
127 if (recvparam!=null) {
128 memberEnter(recvparam, env);
129 recvtype = recvparam.vartype.type;
130 } else {
131 recvtype = null;
132 }
133
134 // Attribute thrown exceptions.
135 ListBuffer<Type> thrownbuf = new ListBuffer<>();
136 for (List<JCExpression> l = thrown; l.nonEmpty(); l = l.tail) {
137 Type exc = attr.attribType(l.head, env);
138 if (!exc.hasTag(TYPEVAR)) {
139 exc = chk.checkClassType(l.head.pos(), exc);
140 } else if (exc.tsym.owner == msym) {
141 //mark inference variables in 'throws' clause
142 exc.tsym.flags_field |= THROWS;
143 }
144 thrownbuf.append(exc);
145 }
146 MethodType mtype = new MethodType(argbuf.toList(),
147 restype,
148 thrownbuf.toList(),
149 syms.methodClass);
150 mtype.recvtype = recvtype;
151
152 return tvars.isEmpty() ? mtype : new ForAll(tvars, mtype);
153 }
154
155 /* ********************************************************************
156 * Visitor methods for member enter
157 *********************************************************************/
158
159 /** Visitor argument: the current environment
160 */
161 protected Env<AttrContext> env;
162
163 /** Enter field and method definitions and process import
164 * clauses, catching any completion failure exceptions.
165 */
166 protected void memberEnter(JCTree tree, Env<AttrContext> env) {
167 Env<AttrContext> prevEnv = this.env;
168 try {
169 this.env = env;
170 tree.accept(this);
171 } catch (CompletionFailure ex) {
172 chk.completionError(tree.pos(), ex);
173 } finally {
174 this.env = prevEnv;
175 }
176 }
177
178 /** Enter members from a list of trees.
179 */
180 void memberEnter(List<? extends JCTree> trees, Env<AttrContext> env) {
181 for (List<? extends JCTree> l = trees; l.nonEmpty(); l = l.tail)
182 memberEnter(l.head, env);
183 }
184
185 public void visitMethodDef(JCMethodDecl tree) {
186 WriteableScope enclScope = enter.enterScope(env);
187 MethodSymbol m = new MethodSymbol(0, tree.name, null, enclScope.owner);
188 m.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, m, tree);
189 tree.sym = m;
190
191 //if this is a default method, add the DEFAULT flag to the enclosing interface
192 if ((tree.mods.flags & DEFAULT) != 0) {
193 m.owner.flags_field |= DEFAULT;
194 }
195
196 Env<AttrContext> localEnv = methodEnv(tree, env);
197 DiagnosticPosition prevLintPos = deferredLintHandler.setPos(tree.pos());
198 try {
199 // Compute the method type
200 m.type = signature(m, tree.typarams, tree.params,
201 tree.restype, tree.recvparam,
202 tree.thrown,
203 localEnv);
204 } finally {
205 deferredLintHandler.setPos(prevLintPos);
206 }
207
208 if (types.isSignaturePolymorphic(m)) {
209 m.flags_field |= SIGNATURE_POLYMORPHIC;
210 }
211
212 // Set m.params
213 ListBuffer<VarSymbol> params = new ListBuffer<>();
214 JCVariableDecl lastParam = null;
215 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail) {
216 JCVariableDecl param = lastParam = l.head;
217 params.append(Assert.checkNonNull(param.sym));
218 }
219 m.params = params.toList();
220
221 // mark the method varargs, if necessary
222 if (lastParam != null && (lastParam.mods.flags & Flags.VARARGS) != 0)
223 m.flags_field |= Flags.VARARGS;
224
225 localEnv.info.scope.leave();
226 if (chk.checkUnique(tree.pos(), m, enclScope)) {
227 enclScope.enter(m);
228 }
229
230 annotate.annotateLater(tree.mods.annotations, localEnv, m, tree.pos());
231 // Visit the signature of the method. Note that
232 // TypeAnnotate doesn't descend into the body.
233 annotate.queueScanTreeAndTypeAnnotate(tree, localEnv, m, tree.pos());
234
235 if (tree.defaultValue != null) {
236 m.defaultValue = annotate.unfinishedDefaultValue(); // set it to temporary sentinel for now
237 annotate.annotateDefaultValueLater(tree.defaultValue, localEnv, m, tree.pos());
238 }
239 }
240
241 /** Create a fresh environment for method bodies.
242 * @param tree The method definition.
243 * @param env The environment current outside of the method definition.
244 */
245 Env<AttrContext> methodEnv(JCMethodDecl tree, Env<AttrContext> env) {
246 Env<AttrContext> localEnv =
247 env.dup(tree, env.info.dup(env.info.scope.dupUnshared(tree.sym)));
248 localEnv.enclMethod = tree;
249 if (tree.sym.type != null) {
250 //when this is called in the enter stage, there's no type to be set
251 localEnv.info.returnResult = attr.new ResultInfo(KindSelector.VAL,
252 tree.sym.type.getReturnType());
253 }
254 if ((tree.mods.flags & STATIC) != 0) localEnv.info.staticLevel++;
255 localEnv.info.yieldResult = null;
256 return localEnv;
257 }
258
259 public void visitVarDef(JCVariableDecl tree) {
260 Env<AttrContext> localEnv = env;
261 if ((tree.mods.flags & STATIC) != 0 ||
262 (env.info.scope.owner.flags() & INTERFACE) != 0) {
263 localEnv = env.dup(tree, env.info.dup());
264 localEnv.info.staticLevel++;
265 }
266 DiagnosticPosition prevLintPos = deferredLintHandler.setPos(tree.pos());
267
268 try {
269 if (TreeInfo.isEnumInit(tree)) {
270 attr.attribIdentAsEnumType(localEnv, (JCIdent)tree.vartype);
271 } else if (!tree.isImplicitlyTyped()) {
272 attr.attribType(tree.vartype, localEnv);
273 if (TreeInfo.isReceiverParam(tree))
274 checkReceiver(tree, localEnv);
275 }
276 } finally {
277 deferredLintHandler.setPos(prevLintPos);
278 }
279
280 if ((tree.mods.flags & VARARGS) != 0) {
281 //if we are entering a varargs parameter, we need to
282 //replace its type (a plain array type) with the more
283 //precise VarargsType --- we need to do it this way
284 //because varargs is represented in the tree as a
285 //modifier on the parameter declaration, and not as a
286 //distinct type of array node.
287 ArrayType atype = (ArrayType)tree.vartype.type;
288 tree.vartype.type = atype.makeVarargs();
289 }
290 WriteableScope enclScope = enter.enterScope(env);
291 Type vartype = tree.isImplicitlyTyped()
292 ? env.info.scope.owner.kind == MTH ? Type.noType : syms.errType
293 : tree.vartype.type;
294 Name name = tree.name;
295 VarSymbol v = new VarSymbol(0, name, vartype, enclScope.owner);
296 v.flags_field = chk.checkFlags(tree.pos(), tree.mods.flags, v, tree);
297 tree.sym = v;
298 if (tree.init != null) {
299 v.flags_field |= HASINIT;
300 if ((v.flags_field & FINAL) != 0 &&
301 needsLazyConstValue(tree.init)) {
302 Env<AttrContext> initEnv = getInitEnv(tree, env);
303 initEnv.info.enclVar = v;
304 initEnv = initEnv(tree, initEnv);
305 initEnv.info.ctorPrologue = (v.owner.kind == TYP && v.owner.isValueClass() && !v.isStatic());
306 v.setLazyConstValue(initEnv, attr, tree);
307 }
308 }
309
310 if(!(Feature.UNNAMED_VARIABLES.allowedInSource(source) && tree.sym.isUnnamedVariable())) {
311 if (chk.checkUnique(tree.pos(), v, enclScope)) {
312 chk.checkTransparentVar(tree.pos(), v, enclScope);
313 enclScope.enter(v);
314 } else if (v.owner.kind == MTH || (v.flags_field & (Flags.PRIVATE | Flags.FINAL | Flags.GENERATED_MEMBER | Flags.RECORD)) != 0) {
315 // if this is a parameter or a field obtained from a record component, enter it
316 enclScope.enter(v);
317 }
318 }
319
320 annotate.annotateLater(tree.mods.annotations, localEnv, v, tree.pos());
321 if (!tree.isImplicitlyTyped()) {
322 annotate.queueScanTreeAndTypeAnnotate(tree.vartype, localEnv, v, tree.pos());
323 }
324
325 v.pos = tree.pos;
326 }
327 // where
328 void checkType(JCTree tree, Type type, Error errorKey) {
329 if (!tree.type.isErroneous() && !types.isSameType(tree.type, type)) {
330 log.error(tree, errorKey);
331 }
332 }
333 void checkReceiver(JCVariableDecl tree, Env<AttrContext> localEnv) {
334 attr.attribExpr(tree.nameexpr, localEnv);
335 MethodSymbol m = localEnv.enclMethod.sym;
336 if (m.isConstructor()) {
337 Type outertype = m.owner.owner.type;
338 if (outertype.hasTag(TypeTag.METHOD)) {
339 // we have a local inner class
340 outertype = m.owner.owner.owner.type;
341 }
342 if (outertype.hasTag(TypeTag.CLASS)) {
343 checkType(tree.vartype, outertype, Errors.IncorrectConstructorReceiverType(outertype, tree.vartype.type));
344 checkType(tree.nameexpr, outertype, Errors.IncorrectConstructorReceiverName(outertype, tree.nameexpr.type));
345 } else {
346 log.error(tree, Errors.ReceiverParameterNotApplicableConstructorToplevelClass);
347 }
348 } else {
349 checkType(tree.vartype, m.owner.type, Errors.IncorrectReceiverType(m.owner.type, tree.vartype.type));
350 checkType(tree.nameexpr, m.owner.type, Errors.IncorrectReceiverName(m.owner.type, tree.nameexpr.type));
351 }
352 }
353
354 public boolean needsLazyConstValue(JCTree tree) {
355 InitTreeVisitor initTreeVisitor = new InitTreeVisitor();
356 tree.accept(initTreeVisitor);
357 return initTreeVisitor.result;
358 }
359
360 /** Visitor class for expressions which might be constant expressions,
361 * as per JLS 15.28 (Constant Expressions).
362 */
363 static class InitTreeVisitor extends JCTree.Visitor {
364
365 private static final Set<Tag> ALLOWED_OPERATORS =
366 EnumSet.of(Tag.POS, Tag.NEG, Tag.NOT, Tag.COMPL, Tag.PLUS, Tag.MINUS,
367 Tag.MUL, Tag.DIV, Tag.MOD, Tag.SL, Tag.SR, Tag.USR,
368 Tag.LT, Tag.LE, Tag.GT, Tag.GE, Tag.EQ, Tag.NE,
369 Tag.BITAND, Tag.BITXOR, Tag.BITOR, Tag.AND, Tag.OR);
370
371 boolean result = true;
372
373 @Override
374 public void visitTree(JCTree tree) {
375 result = false;
376 }
377
378 @Override
379 public void visitLiteral(JCLiteral that) {}
380
381 @Override
382 public void visitTypeCast(JCTypeCast tree) {
383 tree.expr.accept(this);
384 }
385
386 @Override
387 public void visitUnary(JCUnary that) {
388 if (!ALLOWED_OPERATORS.contains(that.getTag())) {
389 result = false;
390 return ;
391 }
392 that.arg.accept(this);
393 }
394
395 @Override
396 public void visitBinary(JCBinary that) {
397 if (!ALLOWED_OPERATORS.contains(that.getTag())) {
398 result = false;
399 return ;
400 }
401 that.lhs.accept(this);
402 that.rhs.accept(this);
403 }
404
405 @Override
406 public void visitConditional(JCConditional tree) {
407 tree.cond.accept(this);
408 tree.truepart.accept(this);
409 tree.falsepart.accept(this);
410 }
411
412 @Override
413 public void visitParens(JCParens tree) {
414 tree.expr.accept(this);
415 }
416
417 @Override
418 public void visitIdent(JCIdent that) {}
419
420 @Override
421 public void visitSelect(JCFieldAccess tree) {
422 tree.selected.accept(this);
423 }
424 }
425
426 /** Create a fresh environment for a variable's initializer.
427 * If the variable is a field, the owner of the environment's scope
428 * is be the variable itself, otherwise the owner is the method
429 * enclosing the variable definition.
430 *
431 * @param tree The variable definition.
432 * @param env The environment current outside of the variable definition.
433 */
434 Env<AttrContext> initEnv(JCVariableDecl tree, Env<AttrContext> env) {
435 Env<AttrContext> localEnv = env.dupto(new AttrContextEnv(tree, env.info.dup()));
436 if (tree.sym.owner.kind == TYP) {
437 localEnv.info.scope = env.info.scope.dupUnshared(tree.sym);
438 }
439 if ((tree.mods.flags & STATIC) != 0 ||
440 ((env.enclClass.sym.flags() & INTERFACE) != 0 && env.enclMethod == null))
441 localEnv.info.staticLevel++;
442 return localEnv;
443 }
444
445 /** Default member enter visitor method: do nothing
446 */
447 public void visitTree(JCTree tree) {
448 }
449
450 public void visitErroneous(JCErroneous tree) {
451 if (tree.errs != null)
452 memberEnter(tree.errs, env);
453 }
454
455 public Env<AttrContext> getMethodEnv(JCMethodDecl tree, Env<AttrContext> env) {
456 Env<AttrContext> mEnv = methodEnv(tree, env);
457 mEnv.info.lint = mEnv.info.lint.augment(tree.sym);
458 for (List<JCTypeParameter> l = tree.typarams; l.nonEmpty(); l = l.tail)
459 mEnv.info.scope.enterIfAbsent(l.head.type.tsym);
460 for (List<JCVariableDecl> l = tree.params; l.nonEmpty(); l = l.tail)
461 mEnv.info.scope.enterIfAbsent(l.head.sym);
462 return mEnv;
463 }
464
465 public Env<AttrContext> getInitEnv(JCVariableDecl tree, Env<AttrContext> env) {
466 Env<AttrContext> iEnv = initEnv(tree, env);
467 return iEnv;
468 }
469 }