Remove left overs from implementing version 0.7.0 of the JSR 305 spec

Fixes #818

Code changes:
- impl of JLS 18.5.3 refreshed from Java 19 spec
- small code unification towards PTB.getNonWildcardParameterization()

Test adjustments:
- fewer captures created cause different capture-names
- wildcards eliminated from some error messages

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/ast/LambdaExpression.java

@@ -533,7 +533,7 @@ private ReferenceBinding findGroundTargetType(BlockScope blockScope, TypeBinding
  freshInferenceContext.cleanUp();
  }
  } else {
- return findGroundTargetTypeForElidedLambda(blockScope, withWildCards);
+ return withWildCards.getNonWildcardParameterization(blockScope);
  }
  }
  if (targetType instanceof ReferenceBinding)
@@ -542,15 +542,6 @@ private ReferenceBinding findGroundTargetType(BlockScope blockScope, TypeBinding
  return null;
  }
 
- public ReferenceBinding findGroundTargetTypeForElidedLambda(BlockScope blockScope, ParameterizedTypeBinding withWildCards) {
- // non-wildcard parameterization (9.8) of the target type
- TypeBinding[] types = withWildCards.getNonWildcardParameterization(blockScope);
- if (types == null)
- return null;
- ReferenceBinding genericType = withWildCards.genericType();
- return blockScope.environment().createParameterizedType(genericType, types, withWildCards.enclosingType());
- }
-
  @Override
  public boolean argumentsTypeElided() {
  return (this.arguments.length > 0 && this.arguments[0].hasElidedType()) || this.argumentsTypeVar;

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/ConstraintExpressionFormula.java

@@ -228,7 +228,7 @@ public static ReferenceBinding findGroundTargetType(InferenceContext18 inference
  LambdaExpression lambda, ParameterizedTypeBinding targetTypeWithWildCards)
  {
  if (lambda.argumentsTypeElided()) {
- return lambda.findGroundTargetTypeForElidedLambda(scope, targetTypeWithWildCards);
+ return targetTypeWithWildCards.getNonWildcardParameterization(scope);
  } else {
  SuspendedInferenceRecord previous = inferenceContext.enterLambda(lambda);
  try {

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/InferenceContext18.java

@@ -34,7 +34,6 @@
 import org.eclipse.jdt.internal.compiler.ast.LambdaExpression;
 import org.eclipse.jdt.internal.compiler.ast.ReferenceExpression;
 import org.eclipse.jdt.internal.compiler.ast.SwitchExpression;
-import org.eclipse.jdt.internal.compiler.ast.Wildcard;
 import org.eclipse.jdt.internal.compiler.lookup.TypeConstants.BoundCheckStatus;
 import org.eclipse.jdt.internal.compiler.util.Sorting;
 
@@ -758,21 +757,37 @@ public ReferenceBinding inferFunctionalInterfaceParameterization(LambdaExpressio
  {
  TypeBinding[] q = createBoundsForFunctionalInterfaceParameterizationInference(targetTypeWithWildCards);
  if (q == null || q.length != lambda.arguments().length) {
- // fail TODO: can this still happen here?
+ return null;
  } else {
  if (reduceWithEqualityConstraints(lambda.argumentTypes(), q)) {
  ReferenceBinding genericType = targetTypeWithWildCards.genericType();
  TypeBinding[] a = targetTypeWithWildCards.arguments; // a is not-null by construction of parameterizedWithWildcard()
  TypeBinding[] aprime = getFunctionInterfaceArgumentSolutions(a);
- // If F<A'1, ..., A'm> is a well-formed type, ...
+ // If F<A'1, ..., A'm> is not a well-formed type, ...
  ParameterizedTypeBinding ptb = blockScope.environment().createParameterizedType(genericType, aprime, targetTypeWithWildCards.enclosingType());
  TypeVariableBinding[] vars = ptb.genericType().typeVariables();
- ParameterizedTypeBinding captured = ptb.capture(blockScope, lambda.sourceStart, lambda.sourceEnd);
+ boolean hasWildcard = false;
  for (int i = 0; i < vars.length; i++) {
- if (vars[i].boundCheck(captured, aprime[i], blockScope, lambda) == BoundCheckStatus.MISMATCH)
- return null;
+ if (vars[i].boundCheck(ptb, aprime[i], blockScope, lambda) == BoundCheckStatus.MISMATCH)
+ return null; // ... no valid parameterization exists
+ hasWildcard |= aprime[i].kind() == Binding.WILDCARD_TYPE;
+ }
+ /* as per spec we should do the following:
+ *
+ * // or if F<A'1, ..., A'm> is not a subtype of F<A1, ..., Am>
+ * if (!ptb.isSubtypeOf(targetTypeWithWildCards, false))
+ * return null; // ... no valid parameterization exists
+ *
+ * but that would surface as
+ * "The target type of this expression is not a well formed parameterized type due to bound(s) mismatch"
+ * whereas the ill-formed type only emerged during inference.
+ * So let final checks detect the incompatibility for a better error message.
+ */
+ if (hasWildcard) {
+ return ptb.getNonWildcardParameterization(blockScope);
+ } else {
+ return ptb;
  }
- return ptb;
  }
  }
  return targetTypeWithWildCards;
@@ -789,34 +804,16 @@ TypeBinding[] createBoundsForFunctionalInterfaceParameterizationInference(Parame
  TypeBinding[] a = functionalInterface.arguments;
  if (a == null)
  return null;
- InferenceVariable[] alpha = addInitialTypeVariableSubstitutions(a);
-
- for (int i = 0; i < a.length; i++) {
- TypeBound bound;
- if (a[i].kind() == Binding.WILDCARD_TYPE) {
- WildcardBinding wildcard = (WildcardBinding) a[i];
- switch(wildcard.boundKind) {
- case Wildcard.EXTENDS :
- bound = new TypeBound(alpha[i], wildcard.allBounds(), ReductionResult.SUBTYPE);
- break;
- case Wildcard.SUPER :
- bound = new TypeBound(alpha[i], wildcard.bound, ReductionResult.SUPERTYPE);
- break;
- case Wildcard.UNBOUND :
- bound = new TypeBound(alpha[i], this.object, ReductionResult.SUBTYPE);
- break;
- default:
- continue; // cannot
- }
- } else {
- bound = new TypeBound(alpha[i], a[i], ReductionResult.SAME);
- }
- this.currentBounds.addBound(bound, this.environment);
- }
+ addInitialTypeVariableSubstitutions(a);
  TypeBinding falpha = substitute(functionalInterface);
  return falpha.getSingleAbstractMethod(this.scope, true).parameters;
  }
 
+ /**
+ * from 18.5.3:
+ * Otherwise, a set of constraint formulas is formed with, for all i (1 ≤ i ≤ n), ‹Pi = Qi›.
+ * This constraint formula set is reduced to form the bound set B.
+ */
  public boolean reduceWithEqualityConstraints(TypeBinding[] p, TypeBinding[] q) {
  if (p != null) {
  for (int i = 0; i < p.length; i++) {
@@ -1797,6 +1794,13 @@ public static ParameterizedTypeBinding parameterizedWithWildcard(TypeBinding typ
  return null;
  }
 
+ /**
+ * From 18.5.3:
+ * <ul>
+ * <li>If B contains an instantiation (§18.1.3) for αi, T, then A'i = T.
+ * <li>Otherwise, A'i = Ai.
+ * </ul>
+ */
  public TypeBinding[] getFunctionInterfaceArgumentSolutions(TypeBinding[] a) {
  int m = a.length;
  TypeBinding[] aprime = new TypeBinding[m];

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/ParameterizedTypeBinding.java

@@ -1629,7 +1629,7 @@ public FieldBinding[] unResolvedFields() {
  @Override
  protected MethodBinding[] getInterfaceAbstractContracts(Scope scope, boolean replaceWildcards, boolean filterDefaultMethods) throws InvalidInputException {
  if (replaceWildcards) {
- TypeBinding[] types = getNonWildcardParameterization(scope);
+ TypeBinding[] types = getNonWildcardParameters(scope);
  if (types == null)
  return new MethodBinding[] { new ProblemMethodBinding(TypeConstants.ANONYMOUS_METHOD, null, ProblemReasons.NotAWellFormedParameterizedType) };
  for (int i = 0; i < types.length; i++) {
@@ -1669,7 +1669,7 @@ public MethodBinding getSingleAbstractMethod(final Scope scope, boolean replaceW
  ParameterizedTypeBinding declaringType = null;
  TypeBinding [] types = this.arguments;
  if (replaceWildcards) {
- types = getNonWildcardParameterization(scope);
+ types = getNonWildcardParameters(scope);
  if (types == null)
  return this.singleAbstractMethod[index] = new ProblemMethodBinding(TypeConstants.ANONYMOUS_METHOD, null, ProblemReasons.NotAWellFormedParameterizedType);
  } else if (types == null) {
@@ -1701,8 +1701,8 @@ public MethodBinding getSingleAbstractMethod(final Scope scope, boolean replaceW
  return this.singleAbstractMethod[index];
  }
 
- // from JLS 9.8
- public TypeBinding[] getNonWildcardParameterization(Scope scope) {
+ // from JLS 9.9
+ public TypeBinding[] getNonWildcardParameters(Scope scope) {
  // precondition: isValidBinding()
  TypeBinding[] typeArguments = this.arguments; // A1 ... An
  if (typeArguments == null)
@@ -1770,6 +1770,16 @@ public TypeBinding[] getNonWildcardParameterization(Scope scope) {
  }
  return types;
  }
+
+ public ReferenceBinding getNonWildcardParameterization(BlockScope blockScope) {
+ // non-wildcard parameterization (9.9) of the target type
+ TypeBinding[] types = getNonWildcardParameters(blockScope);
+ if (types == null)
+ return null;
+ ReferenceBinding genericType = genericType();
+ return blockScope.environment().createParameterizedType(genericType, types, enclosingType());
+ }
+
  @Override
  public long updateTagBits() {
  if (this.arguments != null)

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/GenericsRegressionTest_1_8.java

@@ -2943,7 +2943,7 @@ public void testBug430296() {
  "2. ERROR in AnnotationCollector.java (at line 9)\n" +
  " return persons.collect(Collectors.toMap((Person p) -> p.getLastName(),\n" +
  " ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n" +
- "Type mismatch: cannot convert from Function<Person,? extends K> to Function<? super T,? extends K>\n" +
+ "Type mismatch: cannot convert from Function<Person,K> to Function<? super T,? extends K>\n" +
  "----------\n" +
  "3. ERROR in AnnotationCollector.java (at line 10)\n" +
  " Function::identity,\n" +

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/NegativeLambdaExpressionsTest.java

@@ -8601,12 +8601,12 @@ public void test428177() {
  "4. ERROR in X.java (at line 36)\n" +
  " if(\"1\" == \"\") { return stream.collect(Collectors.toList()).stream(); // ERROR\n" +
  " ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n" +
- "Type mismatch: cannot convert from Stream<capture#24-of ? extends String> to Stream<String>\n" +
+ "Type mismatch: cannot convert from Stream<capture#14-of ? extends String> to Stream<String>\n" +
  "----------\n" +
  "5. ERROR in X.java (at line 38)\n" +
  " return stream.collect(Collectors.toList()); // NO ERROR\n" +
  " ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n" +
- "Type mismatch: cannot convert from List<capture#27-of ? extends String> to Stream<String>\n" +
+ "Type mismatch: cannot convert from List<capture#17-of ? extends String> to Stream<String>\n" +
  "----------\n");
 }
 // https://bugs.eclipse.org/bugs/show_bug.cgi?id=428795, - [1.8]Internal compiler error: java.lang.NullPointerException at org.eclipse.jdt.internal.compiler.ast.MessageSend.analyseCode
@@ -9884,7 +9884,7 @@ public void testGroundTargetTypeWithWithWildcards() {
  "1. ERROR in X.java (at line 10)\n" +
  " return m((X x1, X x2) -> { return new Y(); });\n" +
  " ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n" +
- "Type mismatch: cannot convert from I<X,X,? extends C> to I<? extends A,? extends B,? extends C>\n" +
+ "Type mismatch: cannot convert from I<X,X,C> to I<? extends A,? extends B,? extends C>\n" +
  "----------\n");
 }
 // https://bugs.eclipse.org/bugs/show_bug.cgi?id=474522, [1.8][compiler] ecj doesn't handle captured final fields correctly in lambdas