Remove left-overs from Java 1.7 type inference (#4625)

The following are no longer needed since compiler support for 1.7 was dropped:

+ class InferenceContext
+ methods collectSubstitutes() which held the only remaining references to InferenceContext

See #4625

Author: stephan-herrmann

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

@@ -97,29 +97,6 @@ public List<TypeBinding> collectMissingTypes(List<TypeBinding> missingTypes) {
 	return missingTypes;
 }
 
-@Override
-public void collectSubstitutes(Scope scope, TypeBinding actualType, InferenceContext inferenceContext, int constraint) {
-
-	if ((this.tagBits & TagBits.HasTypeVariable) == 0) return;
-	if (actualType == TypeBinding.NULL || actualType.kind() == POLY_TYPE) return;
-
-	switch(actualType.kind()) {
-		case Binding.ARRAY_TYPE :
-	        int actualDim = actualType.dimensions();
-	        if (actualDim == this.dimensions) {
-			    this.leafComponentType.collectSubstitutes(scope, actualType.leafComponentType(), inferenceContext, constraint);
-	        } else if (actualDim > this.dimensions) {
-	            ArrayBinding actualReducedType = this.environment.createArrayType(actualType.leafComponentType(), actualDim - this.dimensions);
-	            this.leafComponentType.collectSubstitutes(scope, actualReducedType, inferenceContext, constraint);
-	        }
-			break;
-		case Binding.TYPE_PARAMETER :
-			//TypeVariableBinding variable = (TypeVariableBinding) otherType;
-			// TODO (philippe) should consider array bounds, and recurse
-			break;
-	}
-}
-
 @Override
 public boolean mentionsAny(TypeBinding[] parameters, int idx) {
 	return this.leafComponentType.mentionsAny(parameters, idx);

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

@@ -270,116 +270,6 @@ public List<TypeBinding> collectMissingTypes(List<TypeBinding> missingTypes) {
 		return missingTypes;
 	}
 
-	/**
-	 * Collect the substitutes into a map for certain type variables inside the receiver type
-	 * e.g. {@code Collection<T>.collectSubstitutes(Collection<List<X>>, Map)} will populate Map with: {@code T --> List<X>}
-	 * Constraints:
-	 * <pre>{@code
-	 *   A << F   corresponds to:   F.collectSubstitutes(..., A, ..., CONSTRAINT_EXTENDS (1))
-	 *   A = F    corresponds to:   F.collectSubstitutes(..., A, ..., CONSTRAINT_EQUAL (0))
-	 *   A >> F   corresponds to:   F.collectSubstitutes(..., A, ..., CONSTRAINT_SUPER (2))
-	 * }</pre>
-	 */
-	@Override
-	public void collectSubstitutes(Scope scope, TypeBinding actualType, InferenceContext inferenceContext, int constraint) {
-		if ((this.tagBits & TagBits.HasTypeVariable) == 0) {
-			TypeBinding actualEquivalent = actualType.findSuperTypeOriginatingFrom(this.type);
-			if (actualEquivalent != null && actualEquivalent.isRawType()) {
-				inferenceContext.isUnchecked = true;
-			}
-			return;
-		}
-		if (actualType == TypeBinding.NULL || actualType.kind() == POLY_TYPE) return;
-
-		if (!(actualType instanceof ReferenceBinding)) return;
-		TypeBinding formalEquivalent, actualEquivalent;
-		switch (constraint) {
-			case TypeConstants.CONSTRAINT_EQUAL :
-			case TypeConstants.CONSTRAINT_EXTENDS :
-				formalEquivalent = this;
-		        actualEquivalent = actualType.findSuperTypeOriginatingFrom(this.type);
-		        if (actualEquivalent == null) return;
-		        break;
-			case TypeConstants.CONSTRAINT_SUPER :
-	        default:
-		        formalEquivalent = this.findSuperTypeOriginatingFrom(actualType);
-		        if (formalEquivalent == null) return;
-		        actualEquivalent = actualType;
-		        break;
-		}
-		// collect through enclosing type
-		ReferenceBinding formalEnclosingType = formalEquivalent.enclosingType();
-		if (formalEnclosingType != null) {
-			formalEnclosingType.collectSubstitutes(scope, actualEquivalent.enclosingType(), inferenceContext, constraint);
-		}
-		// collect through type arguments
-		if (this.arguments == null) return;
-        TypeBinding[] formalArguments;
-        switch (formalEquivalent.kind()) {
-        	case Binding.GENERIC_TYPE :
-        		formalArguments = formalEquivalent.typeVariables();
-        		break;
-        	case Binding.PARAMETERIZED_TYPE :
-        		formalArguments = ((ParameterizedTypeBinding)formalEquivalent).arguments;
-        		break;
-        	case Binding.RAW_TYPE :
-        		if (inferenceContext.depth > 0) {
-	           		inferenceContext.status = InferenceContext.FAILED; // marker for impossible inference
-        		}
-        		return;
-        	default :
-        		return;
-        }
-        TypeBinding[] actualArguments;
-        switch (actualEquivalent.kind()) {
-        	case Binding.GENERIC_TYPE :
-        		actualArguments = actualEquivalent.typeVariables();
-        		break;
-        	case Binding.PARAMETERIZED_TYPE :
-        		actualArguments = ((ParameterizedTypeBinding)actualEquivalent).arguments;
-        		break;
-        	case Binding.RAW_TYPE :
-        		if (inferenceContext.depth > 0) {
-	           		inferenceContext.status = InferenceContext.FAILED; // marker for impossible inference
-        		} else {
-	        		inferenceContext.isUnchecked = true;
-        		}
-        		return;
-        	default :
-        		return;
-        }
-        inferenceContext.depth++;
-        for (int i = 0, length = formalArguments.length; i < length; i++) {
-        	TypeBinding formalArgument = formalArguments[i];
-        	TypeBinding actualArgument = actualArguments[i];
-        	if (formalArgument.isWildcard()) {
-                formalArgument.collectSubstitutes(scope, actualArgument, inferenceContext, constraint);
-                continue;
-        	} else if (actualArgument.isWildcard()){
-    			WildcardBinding actualWildcardArgument = (WildcardBinding) actualArgument;
-    			if (actualWildcardArgument.otherBounds == null) {
-    				if (constraint == TypeConstants.CONSTRAINT_SUPER) { // JLS 15.12.7, p.459
-						switch(actualWildcardArgument.boundKind) {
-		    				case Wildcard.EXTENDS :
-		    					formalArgument.collectSubstitutes(scope, actualWildcardArgument.bound, inferenceContext, TypeConstants.CONSTRAINT_SUPER);
-		    					continue;
-		    				case Wildcard.SUPER :
-		    					formalArgument.collectSubstitutes(scope, actualWildcardArgument.bound, inferenceContext, TypeConstants.CONSTRAINT_EXTENDS);
-		    					continue;
-		    				default :
-		    					continue; // cannot infer anything further from unbound wildcard
-		    			}
-    				} else {
-    					continue; // cannot infer anything further from wildcard
-    				}
-    			}
-        	}
-        	// by default, use EQUAL constraint
-            formalArgument.collectSubstitutes(scope, actualArgument, inferenceContext, TypeConstants.CONSTRAINT_EQUAL);
-        }
-        inferenceContext.depth--;
-	}
-
 	/**
 	 * @see org.eclipse.jdt.internal.compiler.lookup.ReferenceBinding#computeId()
 	 */

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

@@ -243,21 +243,6 @@ public List<TypeBinding> collectMissingTypes(List<TypeBinding> missingTypes) {
 	return missingTypes;
 }
 
-/**
- * Collect the substitutes into a map for certain type variables inside the receiver type
- * e.g.<pre>{@code
- * Collection<T>.findSubstitute(T, Collection<List<X>>):   T --> List<X>
- *
- * Constraints:
- *   A << F   corresponds to:   F.collectSubstitutes(..., A, ..., CONSTRAINT_EXTENDS (1))
- *   A = F    corresponds to:   F.collectSubstitutes(..., A, ..., CONSTRAINT_EQUAL (0))
- *   A >> F   corresponds to:   F.collectSubstitutes(..., A, ..., CONSTRAINT_SUPER (2))
- * }</pre>
- */
-public void collectSubstitutes(Scope scope, TypeBinding actualType, InferenceContext inferenceContext, int constraint) {
-	// no substitute by default
-}
-
 /** Virtual copy constructor: a copy is made of the receiver's entire instance state and then suitably
     parameterized by the arguments to the clone operation as seen fit by each type. Parameters may not
     make sense for every type in the hierarchy, in which case they are silently ignored. A type may

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

@@ -364,52 +364,6 @@ public List<TypeBinding> collectMissingTypes(List<TypeBinding> missingTypes) {
 		return missingTypes;
 	}
 
-	/**
-	 * Collect the substitutes into a map for certain type variables inside the receiver type
-	 * e.g. {@code Collection<T>.collectSubstitutes(Collection<List<X>>, Map)} will populate Map with: {@code T --> List<X>}
-	 * <pre>{@code
-	 * Constraints:
-	 *   A << F   corresponds to:   F.collectSubstitutes(..., A, ..., CONSTRAINT_EXTENDS (1))
-	 *   A = F    corresponds to:   F.collectSubstitutes(..., A, ..., CONSTRAINT_EQUAL (0))
-	 *   A >> F   corresponds to:   F.collectSubstitutes(..., A, ..., CONSTRAINT_SUPER (2))
-	 * }</pre>
-	 */
-	@Override
-	public void collectSubstitutes(Scope scope, TypeBinding actualType, InferenceContext inferenceContext, int constraint) {
-
-		//	only infer for type params of the generic method
-		if (this.declaringElement != inferenceContext.genericMethod) return;
-
-		// cannot infer anything from a null type
-		switch (actualType.kind()) {
-			case Binding.BASE_TYPE :
-				if (actualType == TypeBinding.NULL) return;
-				TypeBinding boxedType = scope.environment().computeBoxingType(actualType);
-				if (boxedType == actualType) return; //$IDENTITY-COMPARISON$
-				actualType = boxedType;
-				break;
-			case Binding.POLY_TYPE: // cannot steer inference, only learn from it.
-			case Binding.WILDCARD_TYPE :
-				return; // wildcards are not true type expressions (JLS 15.12.2.7, p.453 2nd discussion)
-		}
-
-		// reverse constraint, to reflect variable on rhs:   A << T --> T >: A
-		int variableConstraint;
-		switch(constraint) {
-			case TypeConstants.CONSTRAINT_EQUAL :
-				variableConstraint = TypeConstants.CONSTRAINT_EQUAL;
-				break;
-			case TypeConstants.CONSTRAINT_EXTENDS :
-				variableConstraint = TypeConstants.CONSTRAINT_SUPER;
-				break;
-			default:
-			//case CONSTRAINT_SUPER :
-				variableConstraint =TypeConstants.CONSTRAINT_EXTENDS;
-				break;
-		}
-		inferenceContext.recordSubstitute(this, actualType, variableConstraint);
-	}
-
 	/*
 	 * declaringUniqueKey : genericTypeSignature
 	 * p.X<T> { ... } --> Lp/X;:TT;