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Bug 86654 - Extract the final overrider analysis used by

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SemanticQueries.getPureVirtualMethods() so it can be reused

Change-Id: I5a48bdc3111ac75f2c1ca4f5595fe86defd686b8
Signed-off-by: Nathan Ridge <zeratul976@hotmail.com>
This commit is contained in:
Nathan Ridge 2015-07-18 22:21:55 -04:00 • committed by Sergey Prigogin
parent b0d8f8d3f1
commit d9a2c02fbf
2 changed files with 225 additions and 186 deletions
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202
core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/SemanticQueries.java
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@ -1,5 +1,5 @@
/*******************************************************************************
* Copyright (c) 2012 Nathan Ridge.
* Copyright (c) 2012, 2015 Nathan Ridge.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
@ -14,25 +14,20 @@ import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUti
import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUtil.TDEF;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.eclipse.cdt.core.dom.ast.IASTNode;
import org.eclipse.cdt.core.dom.ast.IBinding;
import org.eclipse.cdt.core.dom.ast.IType;
import org.eclipse.cdt.core.parser.util.CollectionUtils;
import org.eclipse.cdt.internal.core.dom.parser.cpp.ClassTypeHelper;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPSemantics;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPInheritance;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPInheritance.FinalOverriderMap;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPTemplates;
import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUtil;
/**
* This class exposes semantic queries about C++ code to clients such
* as code analysis.
*
*
* @since 5.5
*/
public class SemanticQueries {
@ -86,196 +81,31 @@ public class SemanticQueries {
/**
* Returns all pure virtual methods of a class. Inherited pure virtual methods
* that have not been implemented are also returned.
* that have not been implemented are also returned.
*
* NOTE: The method produces complete results for template instantiations
* but doesn't take into account base classes and methods dependent on unspecified
* template parameters.
*
*
* @param classType the class whose pure virtual methods should be returned
* @param point the point of template instantiation, if applicable
* @return an array containing all pure virtual methods of the class
* @since 5.6
*/
public static ICPPMethod[] getPureVirtualMethods(ICPPClassType classType, IASTNode point) {
return new PureVirtualMethodCollector().collect(classType, point);
}
/** Helper class for {@link #getPureVirtualMethods(ICPPClassType, IASTNode)} */
private static class PureVirtualMethodCollector {
/**
* This class represents a mapping of virtual methods in a class hierarchy
* to their final overriders (see [class.virtual] p2). Since a class hierarchy
* can contain multiple subobjects of the same type (if multiple, non-virtual
* inheritance is used), and the pure virtual methods of each subobject must
* be implemented independently, we give each subobject of a given type a
* number, and for each method we keep track of the final overriders for each
* subobject number. Generally, there should be only one final overrider per
* subobject (in fact the program is ill-formed if there is more than one),
* but to accurately detect pure virtual methods that haven't been overridden,
* we need to be able to keep track of more than one at a time.
*/
private static class FinalOverriderMap {
private Map<ICPPMethod, Map<Integer, List<ICPPMethod>>> fMap = new HashMap<>();
/**
* Add 'overrider' as a final overrider of 'method' in subobject 'subobjectNumber'.
*/
public void add(ICPPMethod method, int subobjectNumber, ICPPMethod overrider) {
Map<Integer, List<ICPPMethod>> overriders = fMap.get(method);
if (overriders == null) {
overriders = new HashMap<>();
fMap.put(method, overriders);
}
CollectionUtils.listMapGet(overriders, subobjectNumber).add(overrider);
}
/**
* For each subobject for which 'method' has been overridden, set
* 'overrider' to be its (only) final overrider.
*/
public void replaceForAllSubobjects(ICPPMethod method, ICPPMethod overrider) {
Map<Integer, List<ICPPMethod>> overriders = fMap.get(method);
if (overriders == null)
return;
for (Integer i : overriders.keySet()) {
List<ICPPMethod> overridersForSubobject = CollectionUtils.listMapGet(overriders, i);
overridersForSubobject.clear();
overridersForSubobject.add(overrider);
}
}
/**
* Merge the final overriders from another FinalOverriderMap into this one.
*/
public void addOverriders(FinalOverriderMap other) {
for (ICPPMethod method : other.fMap.keySet()) {
Map<Integer, List<ICPPMethod>> overriders = fMap.get(method);
if (overriders == null) {
overriders = new HashMap<>();
fMap.put(method, overriders);
}
Map<Integer, List<ICPPMethod>> otherOverriders = other.fMap.get(method);
for (Integer i : otherOverriders.keySet()) {
CollectionUtils.listMapGet(overriders, i).addAll(otherOverriders.get(i));
FinalOverriderMap finalOverriderMap = CPPInheritance.getFinalOverriderMap(classType, point);
List<ICPPMethod> pureVirtualMethods = new ArrayList<>();
for (ICPPMethod method : finalOverriderMap.getMap().keySet()) {
if (method.isPureVirtual()) {
Map<Integer, List<ICPPMethod>> finalOverriders = finalOverriderMap.getMap().get(method);
for (Integer subobjectNumber : finalOverriders.keySet()) {
List<ICPPMethod> overridersForSubobject = finalOverriders.get(subobjectNumber);
if (overridersForSubobject.size() == 1 && overridersForSubobject.get(0) == method) {
pureVirtualMethods.add(method);
}
}
}
/**
* Go through the final overrider map and find functions which are
* pure virtual in the hierarchy's root. These are functions which
* are declared pure virtual, and which have a single final overrider
* which is themself, meaning they have not been overridden.
*/
public ICPPMethod[] collectPureVirtualMethods() {
List<ICPPMethod> pureVirtualMethods = new ArrayList<>();
for (ICPPMethod method : fMap.keySet()) {
if (method.isPureVirtual()) {
Map<Integer, List<ICPPMethod>> finalOverriders = fMap.get(method);
for (Integer subobjectNumber : finalOverriders.keySet()) {
List<ICPPMethod> overridersForSubobject = finalOverriders.get(subobjectNumber);
if (overridersForSubobject.size() == 1 && overridersForSubobject.get(0) == method) {
pureVirtualMethods.add(method);
}
}
}
}
return pureVirtualMethods.toArray(new ICPPMethod[pureVirtualMethods.size()]);
}
}
// The last subobject number used for each type in the hierarchy. This is used to
// assign subobject numbers to subobjects. Virtual subobjects get a subobject
// number of zero, while non-virtual subobjects are number starting from one.
private Map<ICPPClassType, Integer> subobjectNumbers = new HashMap<>();
// Cache of final overrider maps for virtual base subobjects. Since such subobjects
// only occur once in the hierarchy, we can cache the final overrider maps we
// compute for them.
private Map<ICPPClassType, FinalOverriderMap> virtualBaseCache = new HashMap<>();
public ICPPMethod[] collect(ICPPClassType root, IASTNode point) {
FinalOverriderMap finalOverriderMap = collectFinalOverriders(root, false, new HashSet<ICPPClassType>(),
CPPSemantics.MAX_INHERITANCE_DEPTH, point);
return finalOverriderMap.collectPureVirtualMethods();
}
/**
* Compute the final overrider map for a subtree in a class hierarchy.
*
* @param classType the root of the subtree in question
* @param isVirtualBase whether 'classType' is inherited virtually
* @param inheritanceChain the chain of classes from the entire hierarchy's root to 'classType'.
* This is used to guard against circular inheritance.
* @param point the point of template instantiation, if applicable
* @return the computed final overrider map
*/
private FinalOverriderMap collectFinalOverriders(ICPPClassType classType, boolean isVirtualBase,
Set<ICPPClassType> inheritanceChain, int maxdepth, IASTNode point) {
FinalOverriderMap result = new FinalOverriderMap();
inheritanceChain.add(classType);
// Determine the subobject number for the current class.
int subobjectNumber = 0;
if (!isVirtualBase) {
Integer lastNumber = subobjectNumbers.get(classType);
subobjectNumber = (lastNumber == null ? 0 : lastNumber) + 1;
subobjectNumbers.put(classType, subobjectNumber);
}
// Go through our base classes.
for (ICPPBase base : ClassTypeHelper.getBases(classType, point)) {
IBinding baseClass = base.getBaseClass();
if (!(baseClass instanceof ICPPClassType))
continue;
ICPPClassType baseType = (ICPPClassType) baseClass;
// Guard against circular inheritance.
if (inheritanceChain.contains(baseType))
continue;
// Guard against infinite recursion in inheritance
// for example A<I> deriving from A<I - 1> without
// a base case to end the recursion.
if (maxdepth <= 0)
continue;
// Collect final overrider information from the base class.
// If it's a virtual base class and we've already processed it
// in this class hierarchy, don't process it again.
FinalOverriderMap baseOverriderMap;
if (base.isVirtual()) {
baseOverriderMap = virtualBaseCache.get(baseType);
if (baseOverriderMap == null) {
baseOverriderMap = collectFinalOverriders(baseType, true, inheritanceChain, maxdepth - 1, point);
virtualBaseCache.put(baseType, baseOverriderMap);
}
} else {
baseOverriderMap = collectFinalOverriders(baseType, false, inheritanceChain, maxdepth - 1, point);
}
// Merge final overrider information from base class into this class.
result.addOverriders(baseOverriderMap);
}
// Go through our own methods.
for (ICPPMethod method : ClassTypeHelper.getOwnMethods(classType, point)) {
// For purposes of this computation, every virtual method is
// deemed for override itself.
result.add(method, subobjectNumber, method);
// Find all methods overridden by this method, and set their final overrider
// to be this method.
ICPPMethod[] overriddenMethods = ClassTypeHelper.findOverridden(method, point);
for (ICPPMethod overriddenMethod : overriddenMethods)
result.replaceForAllSubobjects(overriddenMethod, method);
}
inheritanceChain.remove(classType);
return result;
}
return pureVirtualMethods.toArray(new ICPPMethod[pureVirtualMethods.size()]);
}
}

209
core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPInheritance.java Normal file
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@ -0,0 +1,209 @@
/*******************************************************************************
* Copyright (c) 2012, 2015 Nathan Ridge.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*******************************************************************************/
package org.eclipse.cdt.internal.core.dom.parser.cpp.semantics;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.eclipse.cdt.core.dom.ast.IASTNode;
import org.eclipse.cdt.core.dom.ast.IBinding;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPBase;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassType;
import org.eclipse.cdt.core.dom.ast.cpp.ICPPMethod;
import org.eclipse.cdt.core.parser.util.CollectionUtils;
import org.eclipse.cdt.internal.core.dom.parser.cpp.ClassTypeHelper;
/**
* Semantic analysis related to inheritance.
*/
public class CPPInheritance {
/**
* This class represents a mapping of virtual methods in a class hierarchy
* to their final overriders (see [class.virtual] p2). Since a class hierarchy
* can contain multiple subobjects of the same type (if multiple, non-virtual
* inheritance is used), and the pure virtual methods of each subobject must
* be implemented independently, we give each subobject of a given type a
* number, and for each method we keep track of the final overriders for each
* subobject number. Generally, there should be only one final overrider per
* subobject (in fact the program is ill-formed if there is more than one),
* but to accurately detect pure virtual methods that haven't been overridden,
* we need to be able to keep track of more than one at a time.
*/
public static class FinalOverriderMap {
private Map<ICPPMethod, Map<Integer, List<ICPPMethod>>> fMap = new HashMap<>();
/**
* Returns the completed final overrider map.
*/
public Map<ICPPMethod, Map<Integer, List<ICPPMethod>>> getMap() {
return fMap;
}
// The methods below are meant to be used while computing the final overrider map.
/**
* Adds 'overrider' as a final overrider of 'method' in subobject 'subobjectNumber'.
*/
void add(ICPPMethod method, int subobjectNumber, ICPPMethod overrider) {
Map<Integer, List<ICPPMethod>> overriders = fMap.get(method);
if (overriders == null) {
overriders = new HashMap<>();
fMap.put(method, overriders);
}
CollectionUtils.listMapGet(overriders, subobjectNumber).add(overrider);
}
/**
* For each subobject for which 'method' has been overridden, sets
* 'overrider' to be its (only) final overrider.
*/
void replaceForAllSubobjects(ICPPMethod method, ICPPMethod overrider) {
Map<Integer, List<ICPPMethod>> overriders = fMap.get(method);
if (overriders == null)
return;
for (Integer i : overriders.keySet()) {
List<ICPPMethod> overridersForSubobject = CollectionUtils.listMapGet(overriders, i);
overridersForSubobject.clear();
overridersForSubobject.add(overrider);
}
}
/**
* Merges the final overriders from another FinalOverriderMap into this one.
*/
void addOverriders(FinalOverriderMap other) {
for (ICPPMethod method : other.fMap.keySet()) {
Map<Integer, List<ICPPMethod>> overriders = fMap.get(method);
if (overriders == null) {
overriders = new HashMap<>();
fMap.put(method, overriders);
}
Map<Integer, List<ICPPMethod>> otherOverriders = other.fMap.get(method);
for (Integer i : otherOverriders.keySet()) {
CollectionUtils.listMapGet(overriders, i).addAll(otherOverriders.get(i));
}
}
}
}
/**
* Returns the final overrider map for a class hierarchy.
*
* @param classType the root of the class hierarchy
* @param point the point of template instantiation, if applicable
* @return the computed final overrider map
*/
public static FinalOverriderMap getFinalOverriderMap(ICPPClassType classType, IASTNode point) {
return FinalOverriderAnalysis.computeFinalOverriderMap(classType, point);
}
private static class FinalOverriderAnalysis {
/**
* Computes the final overrider map for a class hierarchy.
*
* @param classType the root of the class hierarchy
* @param point the point of template instantiation, if applicable
* @return the computed final overrider map
*/
public static FinalOverriderMap computeFinalOverriderMap(ICPPClassType classType, IASTNode point) {
return new FinalOverriderAnalysis().collectFinalOverriders(classType, false,
new HashSet<ICPPClassType>(), CPPSemantics.MAX_INHERITANCE_DEPTH, point);
}
// The last subobject number used for each type in the hierarchy. This is used to
// assign subobject numbers to subobjects. Virtual subobjects get a subobject
// number of zero, while non-virtual subobjects are number starting from one.
private Map<ICPPClassType, Integer> subobjectNumbers = new HashMap<>();
// Cache of final overrider maps for virtual base subobjects. Since such subobjects
// only occur once in the hierarchy, we can cache the final overrider maps we
// compute for them.
private Map<ICPPClassType, FinalOverriderMap> virtualBaseCache = new HashMap<>();
/**
* Recursive helper function for computeFinalOverriderMap() which computes the final overrider map
* for a subtree of a class hierarchy.
*
* @param classType the root of the subtree in question
* @param isVirtualBase whether 'classType' is inherited virtually
* @param inheritanceChain the chain of classes from the entire hierarchy's root to 'classType'.
* This is used to guard against circular inheritance.
* @param point the point of template instantiation, if applicable
* @return the computed final overrider map for the subtree
*/
private FinalOverriderMap collectFinalOverriders(ICPPClassType classType, boolean isVirtualBase,
Set<ICPPClassType> inheritanceChain, int maxdepth, IASTNode point) {
FinalOverriderMap result = new FinalOverriderMap();
inheritanceChain.add(classType);
// Determine the subobject number for the current class.
int subobjectNumber = 0;
if (!isVirtualBase) {
Integer lastNumber = subobjectNumbers.get(classType);
subobjectNumber = (lastNumber == null ? 0 : lastNumber) + 1;
subobjectNumbers.put(classType, subobjectNumber);
}
// Go through our base classes.
for (ICPPBase base : ClassTypeHelper.getBases(classType, point)) {
IBinding baseClass = base.getBaseClass();
if (!(baseClass instanceof ICPPClassType))
continue;
ICPPClassType baseType = (ICPPClassType) baseClass;
// Guard against circular inheritance.
if (inheritanceChain.contains(baseType))
continue;
// Guard against infinite recursion in inheritance
// for example A<I> deriving from A<I - 1> without
// a base case to end the recursion.
if (maxdepth <= 0)
continue;
// Collect final overrider information from the base class.
// If it's a virtual base class and we've already processed it
// in this class hierarchy, don't process it again.
FinalOverriderMap baseOverriderMap;
if (base.isVirtual()) {
baseOverriderMap = virtualBaseCache.get(baseType);
if (baseOverriderMap == null) {
baseOverriderMap = collectFinalOverriders(baseType, true, inheritanceChain, maxdepth - 1, point);
virtualBaseCache.put(baseType, baseOverriderMap);
}
} else {
baseOverriderMap = collectFinalOverriders(baseType, false, inheritanceChain, maxdepth - 1, point);
}
// Merge final overrider information from base class into this class.
result.addOverriders(baseOverriderMap);
}
// Go through our own methods.
for (ICPPMethod method : ClassTypeHelper.getOwnMethods(classType, point)) {
// For purposes of this computation, every virtual method is
// deemed for override itself.
result.add(method, subobjectNumber, method);
// Find all methods overridden by this method, and set their final overrider
// to be this method.
ICPPMethod[] overriddenMethods = ClassTypeHelper.findOverridden(method, point);
for (ICPPMethod overriddenMethod : overriddenMethods)
result.replaceForAllSubobjects(overriddenMethod, method);
}
inheritanceChain.remove(classType);
return result;
}
}
}