Bug 420995 - Specializations of constexpr functions

Change-Id: I7e08e21eb62867d6bb42aa6904ab0fab472cb0bc
Signed-off-by: Nathan Ridge <zeratul976@hotmail.com>
Reviewed-on: https://git.eclipse.org/r/19936
Tested-by: Hudson CI
Reviewed-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>
IP-Clean: Sergey Prigogin <eclipse.sprigogin@gmail.com>
Tested-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>

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

@@ -8251,4 +8251,21 @@ public class AST2TemplateTests extends AST2TestBase {
 	public void testStrayFriends_419301() throws Exception {
 		parseAndCheckBindings();
 	}
+	
+	//	template <typename T>
+	//	constexpr T t(T) {
+	//	    return 0;
+	//	}
+	//
+	//	template <>
+	//	constexpr unsigned t<unsigned>(unsigned) {
+	//	    return 1 + 1;
+	//	}
+	//
+	//	constexpr unsigned waldo = t(0u);
+	public void testSpecializationOfConstexprFunction_420995() throws Exception {
+		BindingAssertionHelper helper = getAssertionHelper();
+		ICPPVariable waldo = helper.assertNonProblem("waldo");
+		assertEquals(2, waldo.getInitialValue().numericalValue().longValue());
+	}
 }

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/internal/index/tests/IndexCPPTemplateResolutionTest.java

@@ -2454,4 +2454,19 @@ public class IndexCPPTemplateResolutionTest extends IndexBindingResolutionTestBa
 	public void testFriendFunctionOfClassSpecialization_419301b() throws Exception {
 		checkBindings();
 	}
+	
+	//	template <typename T>
+	//	constexpr T t(T) {
+	//	    return 0;
+	//	}
+	//
+	//	template <>
+	//	constexpr unsigned t<unsigned>(unsigned) {
+	//	    return 1 + 1;
+	//	}
+	
+	//	// empty source file
+	public void testSpecializationOfConstexprFunction_420995() throws Exception {
+		checkBindings();
+	}
 }

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

@@ -422,7 +422,7 @@ public class Value implements IValue {
 
 		if (expr instanceof ICPPASTInitializerClause) {
 			ICPPEvaluation evaluation = ((ICPPASTInitializerClause) expr).getEvaluation();
-			return new Value(null, evaluation);
+			return evaluation.getValue(expr);
 		}
 		return UNKNOWN;
 	}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPTemplateNonTypeArgument.java

@@ -34,9 +34,15 @@ public class CPPTemplateNonTypeArgument implements ICPPTemplateArgument {
 		if (evaluation instanceof EvalFixed || point == null ||
 				evaluation.isTypeDependent() || evaluation.isValueDependent()) {
 			fEvaluation= evaluation;
+		} else {
+			IValue value = evaluation.getValue(point);
+			// Avoid nesting EvalFixed's as nesting causes the signature to be different.
+			if (value.getEvaluation() instanceof EvalFixed) {
+				fEvaluation = value.getEvaluation();
 			} else {
 				fEvaluation= new EvalFixed(evaluation.getTypeOrFunctionSet(point),
-					evaluation.getValueCategory(point), evaluation.getValue(point));
+						evaluation.getValueCategory(point), value);
+			}
 		}
 	}
 

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

@@ -11,7 +11,6 @@
  *******************************************************************************/
 package org.eclipse.cdt.internal.core.dom.parser.cpp.semantics;
 
-import static org.eclipse.cdt.core.dom.ast.IASTExpression.ValueCategory.PRVALUE;
 import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.ExpressionTypes.typeFromReturnType;
 import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.ExpressionTypes.valueCategoryFromFunctionCall;
 import static org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.ExpressionTypes.valueCategoryFromReturnType;
@@ -149,13 +148,11 @@ public class EvalFunctionCall extends CPPDependentEvaluation {
 	@Override
 	public IValue getValue(IASTNode point) {
 		ICPPEvaluation eval = computeForFunctionCall(Value.MAX_RECURSION_DEPTH, point);
-		if (eval != this) {
+		if (eval == this) {
-			if (eval instanceof EvalFixed)
-				return ((EvalFixed) eval).getValue();
-			eval = new EvalFixed(getTypeOrFunctionSet(point), PRVALUE, eval.getValue(point));
-		}
 			return Value.create(eval);
 		} 
+		return eval.getValue(point);
+	}
 
 	@Override
 	public ValueCategory getValueCategory(IASTNode point) {

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

@@ -28,7 +28,7 @@ public class PDOMCPPConstructorInstance extends PDOMCPPMethodInstance implements
 	@SuppressWarnings("hiding")
 	protected static final int RECORD_SIZE = PDOMCPPMethodInstance.RECORD_SIZE + 0;
 	
-	public PDOMCPPConstructorInstance(PDOMLinkage linkage, PDOMNode parent, ICPPMethod method,
+	public PDOMCPPConstructorInstance(PDOMCPPLinkage linkage, PDOMNode parent, ICPPMethod method,
 			PDOMBinding instantiated) throws CoreException {
 		super(linkage, parent, method, instantiated);
 	}

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

@@ -27,7 +27,7 @@ class PDOMCPPConstructorSpecialization extends PDOMCPPMethodSpecialization imple
 	@SuppressWarnings("hiding")
 	protected static final int RECORD_SIZE = PDOMCPPMethodSpecialization.RECORD_SIZE + 0;
 
-	public PDOMCPPConstructorSpecialization(PDOMLinkage linkage, PDOMNode parent, ICPPConstructor constructor, PDOMBinding specialized) throws CoreException {
+	public PDOMCPPConstructorSpecialization(PDOMCPPLinkage linkage, PDOMNode parent, ICPPConstructor constructor, PDOMBinding specialized) throws CoreException {
 		super(linkage, parent, constructor, specialized);
 	}
 

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

@@ -38,7 +38,7 @@ class PDOMCPPFunctionInstance extends PDOMCPPFunctionSpecialization implements I
 	@SuppressWarnings("hiding")
 	protected static final int RECORD_SIZE = PDOMCPPFunctionSpecialization.RECORD_SIZE + 8;
 	
-	public PDOMCPPFunctionInstance(PDOMLinkage linkage, PDOMNode parent, ICPPFunction function, PDOMBinding orig)
+	public PDOMCPPFunctionInstance(PDOMCPPLinkage linkage, PDOMNode parent, ICPPFunction function, PDOMBinding orig)
 			throws CoreException {
 		super(linkage, parent, function, orig);
 

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

@@ -23,7 +23,6 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPMethod;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPParameter;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPSpecialization;
 import org.eclipse.cdt.internal.core.dom.parser.ProblemFunctionType;
-import org.eclipse.cdt.internal.core.dom.parser.cpp.CPPFunction;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.ICPPComputableFunction;
 import org.eclipse.cdt.internal.core.dom.parser.cpp.ICPPEvaluation;
 import org.eclipse.cdt.internal.core.index.IIndexCPPBindingConstants;
@@ -84,7 +83,7 @@ class PDOMCPPFunctionSpecialization extends PDOMCPPSpecialization
 	private short fAnnotation= -1;
 	private int fRequiredArgCount= -1;
 	
-	public PDOMCPPFunctionSpecialization(PDOMLinkage linkage, PDOMNode parent, ICPPFunction astFunction,
+	public PDOMCPPFunctionSpecialization(PDOMCPPLinkage linkage, PDOMNode parent, ICPPFunction astFunction,
 			PDOMBinding specialized) throws CoreException {
 		super(linkage, parent, (ICPPSpecialization) astFunction, specialized);
 		
@@ -123,10 +122,6 @@ class PDOMCPPFunctionSpecialization extends PDOMCPPSpecialization
 		fAnnotation = getAnnotation(astFunction);
 		db.putShort(record + ANNOTATION, fAnnotation);	
 		db.putShort(record + REQUIRED_ARG_COUNT , (short) astFunction.getRequiredArgumentCount());
-		ICPPEvaluation returnExpression = CPPFunction.getReturnExpression(astFunction);
-		if (returnExpression != null) {
-			linkage.storeEvaluation(record + RETURN_EXPRESSION, returnExpression);
-		}
 		long typelist= 0;
 		if (astFunction instanceof ICPPMethod && ((ICPPMethod) astFunction).isImplicit()) {
 			// Don't store the exception specification, it is computed on demand.
@@ -134,6 +129,7 @@ class PDOMCPPFunctionSpecialization extends PDOMCPPSpecialization
 			typelist = PDOMCPPTypeList.putTypes(this, astFunction.getExceptionSpecification());
 		}
 		db.putRecPtr(record + EXCEPTION_SPEC, typelist);
+		linkage.new ConfigureFunctionSpecialization(astFunction, this);
 	}
 
 	private short getAnnotation(ICPPFunction astFunction) {
@@ -154,6 +150,16 @@ class PDOMCPPFunctionSpecialization extends PDOMCPPSpecialization
 		super(linkage, bindingRecord);
 	}
 	
+	public void initData(ICPPEvaluation returnExpression) {
+		if (returnExpression == null)
+			return;
+		try {
+			getLinkage().storeEvaluation(record + RETURN_EXPRESSION, returnExpression);
+		} catch (CoreException e) {
+			CCorePlugin.log(e);
+		}
+	}
+	
 	@Override
 	protected int getRecordSize() {
 		return RECORD_SIZE;

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

@@ -31,7 +31,7 @@ import org.eclipse.core.runtime.CoreException;
 class PDOMCPPFunctionTemplateSpecialization extends	PDOMCPPFunctionSpecialization 
 		implements ICPPFunctionTemplate, ICPPInstanceCache, IPDOMMemberOwner {
 	
-	public PDOMCPPFunctionTemplateSpecialization(PDOMLinkage linkage, PDOMNode parent,
+	public PDOMCPPFunctionTemplateSpecialization(PDOMCPPLinkage linkage, PDOMNode parent,
 			ICPPFunctionTemplate template, PDOMBinding specialized) throws CoreException {
 		super(linkage, parent, template, specialized);
 	}

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

@@ -252,6 +252,22 @@ class PDOMCPPLinkage extends PDOMLinkage implements IIndexCPPBindingConstants {
 		}
 	}
 	
+	class ConfigureFunctionSpecialization implements Runnable {
+		private final PDOMCPPFunctionSpecialization fSpec; 
+		private final ICPPEvaluation fReturnExpression;
+		
+		public ConfigureFunctionSpecialization(ICPPFunction original, PDOMCPPFunctionSpecialization spec) {
+			fSpec = spec;
+			fReturnExpression = CPPFunction.getReturnExpression(original);
+			postProcesses.add(this);
+		}
+		
+		@Override
+		public void run() {
+			fSpec.initData(fReturnExpression);
+		}
+	}
+
 	class ConfigureFunctionTemplate implements Runnable {
 		private final PDOMCPPFunctionTemplate fTemplate;
 		private final IPDOMCPPTemplateParameter[] fTemplateParameters;

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

@@ -30,7 +30,7 @@ class PDOMCPPMethodInstance extends PDOMCPPFunctionInstance implements ICPPMetho
 	@SuppressWarnings("hiding")
 	protected static final int RECORD_SIZE = PDOMCPPFunctionInstance.RECORD_SIZE + 0;
 	
-	public PDOMCPPMethodInstance(PDOMLinkage linkage, PDOMNode parent, ICPPMethod method, PDOMBinding instantiated)
+	public PDOMCPPMethodInstance(PDOMCPPLinkage linkage, PDOMNode parent, ICPPMethod method, PDOMBinding instantiated)
 			throws CoreException {
 		super(linkage, parent, method, instantiated);
 	}

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

@@ -51,7 +51,7 @@ class PDOMCPPMethodSpecialization extends PDOMCPPFunctionSpecialization
 	 */
 	private static final int CV_OFFSET = PDOMCPPAnnotation.MAX_EXTRA_OFFSET + 1;
 	
-	public PDOMCPPMethodSpecialization(PDOMLinkage linkage, PDOMNode parent, ICPPMethod method, PDOMBinding specialized) throws CoreException {
+	public PDOMCPPMethodSpecialization(PDOMCPPLinkage linkage, PDOMNode parent, ICPPMethod method, PDOMBinding specialized) throws CoreException {
 		super(linkage, parent, method, specialized);		
 		Database db = getDB();