Bug 459940 - Sfinae in id-expression

Change-Id: I6cfaf2af680c3b41571d4714f9a5511ff81af42b
Signed-off-by: Nathan Ridge <zeratul976@hotmail.com>

4 files changed, 36 insertions, 2 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 2008a13a293..63044426531 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
@@ -7561,6 +7561,31 @@ public class AST2TemplateTests extends AST2TestBase {
 		parseAndCheckBindings();
 	}
 	
+	//	template<typename _From>
+	//	struct is_convertible {};
+	//
+	//	class function {
+	//	public:
+	//	  template<typename _Functor, bool = is_convertible<_Functor>::type::value>
+	//	  function(_Functor);
+	//	};
+	//
+	//	class A {};
+	//
+	//	struct B {
+	//	  B(const char* s);
+	//	};
+	//
+	//	template <class T> void waldo(const B& b);
+	//	template <class T> void waldo(function f);
+	//
+	//	void test() {
+	//	    waldo<A>(""); // problem on waldo
+	//	}
+	public void testSfinaeInIdExpression_459940() throws Exception {
+		parseAndCheckBindings();
+	}
+	
 	//	template <typename>
 	//	struct M {
 	//	    template <typename... Args>
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/Value.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/Value.java
index a364c4c22be..ac72bf97e20 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/Value.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/Value.java
@@ -85,7 +85,12 @@ import org.eclipse.core.runtime.CoreException;
  */
 public class Value implements IValue {
 	public static final int MAX_RECURSION_DEPTH = 25;
+	// Value.UNKNOWN indicates general inability to determine a value. It doesn't have to be an error,
+	// it could be that evaluation ran into a performance limit, or that we can't model this kind of
+	// value (such as a pointer to a function).
 	public static final Value UNKNOWN= new Value("<unknown>".toCharArray(), null); //$NON-NLS-1$
+	// Value.ERROR indicates that an error, such as a substitution failure, occurred during evaluation.
+	public static final Value ERROR= new Value("<error>".toCharArray(), null); //$NON-NLS-1$
 	public static final Value NOT_INITIALIZED= new Value("<__>".toCharArray(), null); //$NON-NLS-1$
 	private static final IType INT_TYPE= new CPPBasicType(ICPPBasicType.Kind.eInt, 0);
 
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalFixed.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalFixed.java
index 877fa763b01..3d69847c864 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalFixed.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalFixed.java
@@ -34,7 +34,7 @@ import org.eclipse.core.runtime.CoreException;
  */
 public class EvalFixed extends CPPEvaluation {
 	public static final ICPPEvaluation INCOMPLETE =
-			new EvalFixed(ProblemType.UNKNOWN_FOR_EXPRESSION, PRVALUE, Value.UNKNOWN);
+			new EvalFixed(ProblemType.UNKNOWN_FOR_EXPRESSION, PRVALUE, Value.ERROR);
 
 	private final IType fType;
 	private final IValue fValue;
@@ -170,6 +170,10 @@ public class EvalFixed extends CPPEvaluation {
 		IValue value = CPPTemplates.instantiateValue(fValue, tpMap, packOffset, within, maxdepth, point);
 		if (type == fType && value == fValue)
 			return this;
+		// If an error occurred while instantiating the value (such as a substitution failure), 
+		// propagate that error.
+		if (value == Value.ERROR)
+			return EvalFixed.INCOMPLETE;
 		return new EvalFixed(type, fValueCategory, value);
 	}
 
diff --git a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalID.java b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalID.java
index 77c442ec60f..e89cdf1da66 100644
--- a/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalID.java
+++ b/core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/semantics/EvalID.java
@@ -342,7 +342,7 @@ public class EvalID extends CPPDependentEvaluation {
 		}
 
 		if (fieldOwner instanceof IProblemBinding || nameOwner instanceof IProblemBinding)
-			return this;
+			return EvalFixed.INCOMPLETE;
 
 		if (templateArgs == fTemplateArgs && fieldOwner == fFieldOwner && nameOwner == fNameOwner)
 			return this;