Bug 517670 - Handle instantiation of closure types

Change-Id: I82208dbb2ec0e11760cbd78a073acefa627d8d36

4 files changed, 128 insertions, 8 deletions

diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/cxx14/VariableTemplateTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/cxx14/VariableTemplateTests.java
index 4b0b0afe021..360ce84a7db 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/cxx14/VariableTemplateTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/cxx14/VariableTemplateTests.java
@@ -11,7 +11,6 @@
  *******************************************************************************/
 package org.eclipse.cdt.core.parser.tests.ast2.cxx14;
 
-import org.eclipse.cdt.core.dom.ast.IASTTranslationUnit;
 import org.eclipse.cdt.core.dom.ast.IType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTVisibilityLabel;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPField;
@@ -23,13 +22,13 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPVariable;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPVariableInstance;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPVariableTemplate;
 import org.eclipse.cdt.core.parser.ParserLanguage;
-import org.eclipse.cdt.core.parser.tests.ast2.AST2TestBase;
+import org.eclipse.cdt.core.parser.tests.ast2.AST2CPPTestBase;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPClassInstance;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPFieldTemplateSpecialization;
 
 import junit.framework.TestSuite;
 
-public class VariableTemplateTests extends AST2TestBase {
+public class VariableTemplateTests extends AST2CPPTestBase {
 
 	public static TestSuite suite() {
 		return suite(VariableTemplateTests.class);
@@ -362,8 +361,13 @@ public class VariableTemplateTests extends AST2TestBase {
 		ICPPVariable waldo2 = ah.assertNonProblem("waldo2");
 		assertVariableValue(waldo2, 0);
 	}
-
-	private IASTTranslationUnit parseAndCheckBindings() throws Exception {
-		return parseAndCheckBindings(getAboveComment(), ParserLanguage.CPP);
+	
+	//	template <typename R>
+	//	auto L = []{ return R{}; };
+	//
+	//	decltype(L<int>()) waldo;
+	public void testLambdaValue_517670() throws Exception {
+		BindingAssertionHelper helper = getAssertionHelper();
+		helper.assertVariableType("waldo", CommonCPPTypes.int_);
 	}
 }
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureSpecialization.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureSpecialization.java
new file mode 100644
index 00000000000..8399bccbba9
--- /dev/null
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureSpecialization.java
@@ -0,0 +1,105 @@
+package org.eclipse.cdt.internal.core.dom.parser.cpp;
+
+import org.eclipse.cdt.core.dom.ast.IASTNode;
+import org.eclipse.cdt.core.dom.ast.IBinding;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTLambdaExpression;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPBase;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassSpecialization;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPClassType;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPConstructor;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPField;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPMethod;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPTemplateParameterMap;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPUsingDeclaration;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPTemplates;
+
+/**
+ * Specialization of a closure type.
+ */
+public class CPPClosureSpecialization extends CPPClosureType implements ICPPClassSpecialization {
+	private CPPClosureType fSpecialized;
+	private ICPPTemplateParameterMap fMap;
+	
+	public CPPClosureSpecialization(ICPPASTLambdaExpression lambda, CPPClosureType specialized,
+			InstantiationContext context) {
+		super(lambda);
+		fSpecialized = specialized;
+		fMap = context.getParameterMap();
+		ICPPMethod[] methods = specialized.getMethods();
+		fMethods = new ICPPMethod[methods.length];
+		for (int i = 0; i < methods.length; ++i) {
+			fMethods[i] = (ICPPMethod) specializeMember(methods[i]);
+		}
+	}
+
+	@Override
+	public ICPPTemplateParameterMap getTemplateParameterMap() {
+		return fMap;
+	}
+
+	@Override
+	public ICPPClassType getSpecializedBinding() {
+		return fSpecialized;
+	}
+
+	@Override
+	public IBinding specializeMember(IBinding binding) {
+		// TODO: Cache specialized members the way class template specializations do?
+		return CPPTemplates.createSpecialization(this, binding);
+	}
+
+	@Override
+	public IBinding specializeMember(IBinding binding, IASTNode point) {
+		return specializeMember(binding);
+	}
+
+	@Override
+	public ICPPBase[] getBases(IASTNode point) {
+		return ICPPBase.EMPTY_BASE_ARRAY;
+	}
+
+	@Override
+	public ICPPConstructor[] getConstructors(IASTNode point) {
+		return getConstructors();
+	}
+
+	@Override
+	public ICPPField[] getDeclaredFields(IASTNode point) {
+		return ICPPField.EMPTY_CPPFIELD_ARRAY;
+	}
+
+	@Override
+	public ICPPMethod[] getMethods(IASTNode point) {
+		return getMethods();
+	}
+
+	@Override
+	public ICPPMethod[] getAllDeclaredMethods(IASTNode point) {
+		return ICPPMethod.EMPTY_CPPMETHOD_ARRAY;
+	}
+
+	@Override
+	public ICPPMethod[] getDeclaredMethods(IASTNode point) {
+		return ICPPMethod.EMPTY_CPPMETHOD_ARRAY;
+	}
+
+	@Override
+	public IBinding[] getFriends(IASTNode point) {
+		return IBinding.EMPTY_BINDING_ARRAY;
+	}
+
+	@Override
+	public ICPPField[] getFields(IASTNode point) {
+		return ICPPField.EMPTY_CPPFIELD_ARRAY;
+	}
+
+	@Override
+	public ICPPClassType[] getNestedClasses(IASTNode point) {
+		return ICPPClassType.EMPTY_CLASS_ARRAY;
+	}
+
+	@Override
+	public ICPPUsingDeclaration[] getUsingDeclarations(IASTNode point) {
+		return ICPPUsingDeclaration.EMPTY_USING_DECL_ARRAY;
+	}
+}
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureType.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureType.java
index 492651e84bb..2c062d53131 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureType.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPClosureType.java
@@ -69,7 +69,7 @@ public class CPPClosureType extends PlatformObject implements ICPPClassType, ICP
 	private final ICPPASTLambdaExpression fLambdaExpression;
 	private IType[] fParameterTypes;
 	private ICPPParameter[] fParameters;
-	private ICPPMethod[] fMethods;
+	protected ICPPMethod[] fMethods;
 	private ClassScope fScope;
 	// Used for generic lambdas; null otherwise.
 	private ICPPTemplateParameter[] fInventedTemplateParameters;
@@ -77,7 +77,7 @@ public class CPPClosureType extends PlatformObject implements ICPPClassType, ICP
 	public CPPClosureType(ICPPASTLambdaExpression lambdaExpr) {
 		fLambdaExpression= lambdaExpr;
 	}
-
+	
 	private ICPPMethod[] createMethods() {
 		boolean needConversionOperator=
 			fLambdaExpression.getCaptureDefault() == CaptureDefault.UNSPECIFIED &&
@@ -451,6 +451,12 @@ public class CPPClosureType extends PlatformObject implements ICPPClassType, ICP
 		throw new IllegalArgumentException(member.getName() + " is not a member of closure type '" //$NON-NLS-1$
 				+ fLambdaExpression.getRawSignature() + "'"); //$NON-NLS-1$
 	}
+	
+	// A lambda expression can appear in a dependent context, such as in the value of
+	// a variable template, so it needs to be instantiable.
+	public CPPClosureType instantiate(InstantiationContext context) {
+		return new CPPClosureSpecialization(fLambdaExpression, this, context);
+	}
 
 	private final class ClassScope implements ICPPClassScope {
 		@Override
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java
index b575b455836..58c6af7f199 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/CPPTemplates.java
@@ -143,6 +143,7 @@ import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPClassSpecialization.Recur
 import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPClassTemplatePartialSpecialization;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPClassTemplatePartialSpecializationSpecialization;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPClassTemplateSpecialization;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPClosureType;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPConstructorInstance;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPConstructorSpecialization;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPConstructorTemplateSpecialization;
@@ -1663,6 +1664,10 @@ public class CPPTemplates {
 					default:              return null;  // shouldn't happen
 				}
 			}
+			
+			if (type instanceof CPPClosureType) {
+				return ((CPPClosureType) type).instantiate(context);
+			}
 
 			return type;
 		} catch (DOMException e) {