Bug 388805 - False ambiguity in overload resolution with variadicrefs/changes/43/9643/3

templates

Change-Id: I4d8b73ab5238f98de7b53849b265ebbc6158d62e
Reviewed-on: https://git.eclipse.org/r/9643
Reviewed-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>
IP-Clean: Sergey Prigogin <eclipse.sprigogin@gmail.com>
Tested-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>

3 files changed, 38 insertions, 4 deletions

diff --git a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
index da6898a..fb687f0 100644
--- a/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
+++ b/core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2TemplateTests.java
@@ -4405,6 +4405,17 @@ public class AST2TemplateTests extends AST2TestBase {
 		parseAndCheckBindings();
 	}
 
+	//	template <typename A>
+	//	void foo(A);
+	//	template <typename A, typename... B>
+	//	void foo(A, B...);
+	//	int main() {
+	//	    foo(0);
+	//	}
+	public void testFunctionTemplatePartialOrdering_388805() throws Exception {
+		parseAndCheckBindings();
+	}
+
 	//	template<typename T> class CT {};
 	//	template<int I> class CTI {};
 	//
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 9a3a324..73dcc32 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
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2005, 2012 IBM Corporation and others.
+ * Copyright (c) 2005, 2013 IBM Corporation and others.
  * 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
@@ -81,6 +81,7 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPFunction;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPFunctionTemplate;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPFunctionType;
 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.ICPPParameterPackType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPPointerToMemberType;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPScope;
@@ -1958,13 +1959,34 @@ public class CPPTemplates {
 		return arg;
 	}
 
+	private static ICPPFunctionType getFunctionTypeIgnoringParametersWithDefaults(ICPPFunction function) {
+		ICPPParameter[] parameters = function.getParameters();
+		IType[] parameterTypes = new IType[parameters.length];
+		int i;
+		for (i = 0; i < parameters.length; ++i) {
+			ICPPParameter parameter = parameters[i];
+			if (!parameter.hasDefaultValue()) {
+				parameterTypes[i] = parameter.getType();
+			} else {
+				break;
+			}
+		}
+		ICPPFunctionType originalType = function.getType();
+		if (i == parameters.length)  // no parameters with default arguments
+			return originalType;
+		return new CPPFunctionType(originalType.getReturnType(), ArrayUtil.trim(parameterTypes),
+				originalType.isConst(), originalType.isVolatile(), originalType.takesVarArgs());
+	}
+
 	private static int compareSpecialization(ICPPFunctionTemplate f1, ICPPFunctionTemplate f2, TypeSelection mode, IASTNode point) throws DOMException {
 		ICPPFunction transF1 = transferFunctionTemplate(f1, point);
 		if (transF1 == null)
 			return -1;
 
 		final ICPPFunctionType ft2 = f2.getType();
-		final ICPPFunctionType transFt1 = transF1.getType();
+		// Ignore parameters with default arguments in the transformed function template
+		// as per [temp.func.order] p5.
+		final ICPPFunctionType transFt1 = getFunctionTypeIgnoringParametersWithDefaults(transF1);
 		IType[] pars;
 		IType[] args;
 		switch(mode) {
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/TemplateArgumentDeduction.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/TemplateArgumentDeduction.java
index 6319e0c..8f8328c 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/TemplateArgumentDeduction.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/TemplateArgumentDeduction.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2012 Wind River Systems, Inc. and others.
+ * Copyright (c) 2009, 2013 Wind River Systems, Inc. and others.
  * 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
@@ -8,6 +8,7 @@
  * Contributors:
  *     Markus Schorn - initial API and implementation
  *     Sergey Prigogin (Google)
+ *     Nathan Ridge
  *******************************************************************************/ 
 package org.eclipse.cdt.internal.core.dom.parser.cpp.semantics;
 
@@ -431,7 +432,7 @@ public class TemplateArgumentDeduction {
 					deduct.incPackOffset();
 				} else  {
 					if (j >= fnParCount) 
-						return result;
+						return -1;
 					
 					par= fnPars[j];
 					if (par instanceof ICPPParameterPackType) {