Fix pack expansion for array elements

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java

@@ -18,6 +18,7 @@
  *     Nathan Ridge
  *     Danny Ferreira
  *     Marc-Andre Laperle (Ericsson)
+ *     Igor V. Kovalenko
  *******************************************************************************/
 package org.eclipse.cdt.core.parser.tests.ast2;
 
@@ -11400,4 +11401,22 @@ public void testIntegerPack_553794() throws Exception {
 		ITypedef type2 = helper.assertNonProblem("type2");
 		assertSameType(type1, type2);
 	}
+
+	//	using size_t = decltype(sizeof(int));
+	//
+	//	template<typename T> struct A {
+	//		static constexpr size_t f(const T& arg) noexcept { return sizeof(arg); }
+	//	};
+	//
+	//	template<typename... Pack>
+	//	constexpr size_t g(const Pack&... pack) { return A<Pack...>::f(pack...); }
+	//
+	//	static constexpr auto val1 = g("123");
+	//	static constexpr auto val2 = g((const char*)"123");
+	public void testParameterPackExpansions_array() throws Exception {
+		parseAndCheckBindings();
+		BindingAssertionHelper helper = getAssertionHelper();
+		helper.assertVariableValue("val1", 4);
+		helper.assertVariableValue("val2", 8);
+	}
 }

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/ITypeMarshalBuffer.java

@@ -45,7 +45,7 @@ public interface ITypeMarshalBuffer {
 			EVAL_FUNCTION_SET = 0x09, EVAL_ID = 0x0A, EVAL_INIT_LIST = 0x0B, EVAL_MEMBER_ACCESS = 0x0C,
 			EVAL_PACK_EXPANSION = 0x0D, EVAL_TYPE_ID = 0x0E, EVAL_UNARY = 0x0F, EVAL_UNARY_TYPE_ID = 0x10,
 			EVAL_CONSTRUCTOR = 0x11, EVAL_REFERENCE = 0x12, EVAL_POINTER = 0x13, EVAL_COMPOSITE_ACCESS = 0x14,
-			EVAL_NARY_TYPE_ID = 0x15;
+			EVAL_NARY_TYPE_ID = 0x15, EVAL_PACK_ACCESS = 0x16;
 	// Can add more evaluations up to 0x1C, after that it will collide with TypeMarshalBuffer.UNSTORABLE_TYPE.
 
 	final static byte EXEC_COMPOUND_STATEMENT = 0x01, EXEC_BREAK = 0x02, EXEC_CASE = 0x03, EXEC_CONTINUE = 0x04,

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalBinding.java

@@ -454,7 +454,7 @@ public ICPPEvaluation instantiate(InstantiationContext context, int maxDepth) {
 				newBindingEval = new EvalBinding(newBinding, newBinding.getType(), getTemplateDefinition());
 			}
 			if (context.hasPackOffset()) {
-				return new EvalCompositeAccess(newBindingEval, packOffset);
+				return new EvalPackAccess(newBindingEval, packOffset);
 			} else {
 				return newBindingEval;
 			}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalCompositeAccess.java

@@ -39,7 +39,7 @@
  * Represents an access to a sub-value of a composite value, identified by an index.
  * Composite values can include arrays, structures, and parameter packs (see {@code CompositeValue}).
  */
-public final class EvalCompositeAccess implements ICPPEvaluation {
+public class EvalCompositeAccess implements ICPPEvaluation {
 	private final ICPPEvaluation parent; // The composite value being accessed
 	private final int elementId; // The index of the sub-value being accessed
 

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalPackAccess.java

@@ -0,0 +1,52 @@
+/*******************************************************************************
+* Copyright (c) 2016,2022 Institute for Software, HSR Hochschule fuer Technik and others
+* Rapperswil, University of applied sciences and others
+*
+* This program and the accompanying materials
+* are made available under the terms of the Eclipse Public License 2.0
+* which accompanies this distribution, and is available at
+* https://www.eclipse.org/legal/epl-2.0/
+*
+* SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Igor V. Kovalenko - factor out EvalPackAccess
+*******************************************************************************/
+package org.eclipse.cdt.internal.core.dom.parser.cpp.semantics;
+
+import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUtil.CVTYPE;
+import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUtil.REF;
+import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.SemanticUtil.TDEF;
+
+import org.eclipse.cdt.core.dom.ast.IType;
+import org.eclipse.cdt.internal.core.dom.parser.ITypeMarshalBuffer;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.ICPPEvaluation;
+import org.eclipse.core.runtime.CoreException;
+
+public class EvalPackAccess extends EvalCompositeAccess {
+
+	public EvalPackAccess(ICPPEvaluation parent, int elementId) {
+		super(parent, elementId);
+	}
+
+	@Override
+	public IType getType() {
+		IType type = getParent().getType();
+		type = SemanticUtil.getNestedType(type, TDEF | REF | CVTYPE);
+
+		return type;
+	}
+
+	@Override
+	public void marshal(ITypeMarshalBuffer buffer, boolean includeValue) throws CoreException {
+		buffer.putShort(ITypeMarshalBuffer.EVAL_PACK_ACCESS);
+		buffer.marshalEvaluation(getParent(), includeValue);
+		buffer.putInt(getElementId());
+	}
+
+	public static ICPPEvaluation unmarshal(short firstBytes, ITypeMarshalBuffer buffer) throws CoreException {
+		ICPPEvaluation parent = buffer.unmarshalEvaluation();
+		int elementId = buffer.getInt();
+		return new EvalPackAccess(parent, elementId);
+	}
+}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/pdom/dom/cpp/PDOMCPPLinkage.java

@@ -136,6 +136,7 @@
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalInitList;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalMemberAccess;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalNaryTypeId;
+import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalPackAccess;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalPackExpansion;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalPointer;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.EvalReference;
@@ -1726,6 +1727,8 @@ public ICPPEvaluation unmarshalEvaluation(ITypeMarshalBuffer buffer) throws Core
 			return EvalCompositeAccess.unmarshal(firstBytes, buffer);
 		case ITypeMarshalBuffer.EVAL_NARY_TYPE_ID:
 			return EvalNaryTypeId.unmarshal(firstBytes, buffer);
+		case ITypeMarshalBuffer.EVAL_PACK_ACCESS:
+			return EvalPackAccess.unmarshal(firstBytes, buffer);
 		}
 		throw new CoreException(CCorePlugin.createStatus("Cannot unmarshal an evaluation, first bytes=" + firstBytes)); //$NON-NLS-1$
 	}