Improve ProblemBinding checker message for failed function instantiat…

…ion (#668)

Display the new more accurate error when all candidates were failed
instantiations. Otherwise, if there is a mix of failed instantiation and
wrong number of arguments, display the old message.
This could really be improved even more...

template<typename T>
void function() {}

Before:
function(); // Invalid arguments 'Candidates are:

After:
function(); // Cannot instantiate template function 'Candidates are:

codan/org.eclipse.cdt.codan.checkers/META-INF/MANIFEST.MF

@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %Bundle-Name
 Bundle-SymbolicName: org.eclipse.cdt.codan.checkers;singleton:=true
-Bundle-Version: 3.5.400.qualifier
+Bundle-Version: 3.5.500.qualifier
 Bundle-Activator: org.eclipse.cdt.codan.checkers.CodanCheckersActivator
 Require-Bundle: org.eclipse.core.runtime,
  org.eclipse.core.resources,

codan/org.eclipse.cdt.codan.checkers/OSGI-INF/l10n/bundle.properties

@@ -116,6 +116,9 @@ problem.name.12 = Field cannot be resolved
 problem.description.13 = Name resolution problem found by the indexer
 problem.messagePattern.13 = Structured binding initializer expression refers to introduced name ''{0}''
 problem.name.13 = Invalid structured binding declaration
+problem.description.14 = Name resolution problem found by the indexer
+problem.messagePattern.14 = Cannot instantiate template function ''{0}''
+problem.name.14 = Function cannot be instantiated
 checker.name.AbstractClassCreation = Abstract class cannot be instantiated
 problem.name.AbstractClassCreation = Abstract class cannot be instantiated
 problem.messagePattern.AbstractClassCreation = The type ''{0}'' must implement the inherited pure virtual method ''{1}''\u0020

codan/org.eclipse.cdt.codan.checkers/plugin.xml

@@ -253,6 +253,16 @@
                messagePattern="%problem.messagePattern.10"
                name="%problem.name.10">
          </problem>
+         <problem
+               category="org.eclipse.cdt.codan.core.categories.CompilerErrors"
+               defaultEnabled="true"
+               defaultSeverity="Error"
+               description="%problem.description.14"
+               id="org.eclipse.cdt.codan.internal.checkers.TemplateInstantiationProblem"
+               markerType="org.eclipse.cdt.codan.core.codanSemanticProblem"
+               messagePattern="%problem.messagePattern.14"
+               name="%problem.name.14">
+         </problem>
          <problem
                category="org.eclipse.cdt.codan.core.categories.CompilerErrors"
                defaultEnabled="true"

codan/org.eclipse.cdt.codan.checkers/src/org/eclipse/cdt/codan/internal/checkers/ProblemBindingChecker.java

@@ -66,6 +66,7 @@ public class ProblemBindingChecker extends AbstractIndexAstChecker {
 	public static String ERR_ID_VariableResolutionProblem = "org.eclipse.cdt.codan.internal.checkers.VariableResolutionProblem"; //$NON-NLS-1$
 	public static String ERR_ID_Candidates = "org.eclipse.cdt.codan.internal.checkers.Candidates"; //$NON-NLS-1$
 	public static String ERR_ID_StructuredBindingDeclarationProblem = "org.eclipse.cdt.codan.internal.checkers.StructuredBindingDeclarationProblem"; //$NON-NLS-1$
+	public static String ERR_ID_TemplateInstantiationProblem = "org.eclipse.cdt.codan.internal.checkers.TemplateInstantiationProblem"; //$NON-NLS-1$
 
 	@Override
 	public boolean runInEditor() {
@@ -175,6 +176,14 @@ public int visit(IASTName name) {
 										contextFlagsString);
 								return PROCESS_CONTINUE;
 							}
+							if (id == IProblemBinding.SEMANTIC_INVALID_TEMPLATE_INSTANTIATION) {
+								if (isFunctionCall(name, parentNode)) {
+									reportProblem(ERR_ID_TemplateInstantiationProblem, name.getLastName(),
+											getCandidatesString(problemBinding), contextFlagsString);
+								}
+								return PROCESS_CONTINUE;
+							}
+
 							// From this point, we'll deal only with NAME_NOT_FOUND problems.
 							// If it's something else continue because we don't want to give bad messages.
 							if (id != IProblemBinding.SEMANTIC_NAME_NOT_FOUND) {

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

@@ -480,7 +480,7 @@ public void test_dr1591_DeduceArrayFromInitializerList_c() throws Exception {
 		assertInstance(fCall, IProblemBinding.class);
 
 		IProblemBinding fCallPB = (IProblemBinding) fCall;
-		assertEquals(IProblemBinding.SEMANTIC_NAME_NOT_FOUND, fCallPB.getID());
+		assertEquals(IProblemBinding.BINDING_INVALID_TEMPLATE_INSTANTIATION, fCallPB.getID());
 	}
 
 	// template < class T, template < class X > class U, T *pT > class A {
@@ -7487,7 +7487,7 @@ public void testTemplatedAliasRedefinitionOfSameFunction() throws Exception {
 	public void testTemplatedAliasDeduction() throws Exception {
 		BindingAssertionHelper bh = getAssertionHelper();
 		bh.assertNonProblem("g(v)", "g", ICPPFunction.class);
-		bh.assertProblem("f(v)", "f", ISemanticProblem.BINDING_NOT_FOUND);
+		bh.assertProblem("f(v)", "f", ISemanticProblem.BINDING_INVALID_TEMPLATE_INSTANTIATION);
 	}
 
 	// using function = void (&)(int);

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/IProblemBinding.java

@@ -67,6 +67,8 @@ public interface IProblemBinding extends IBinding, IScope, IType, ISemanticProbl
 	public static final int SEMANTIC_INVALID_TEMPLATE_ARGUMENTS = BINDING_INVALID_TEMPLATE_ARGUMENTS;
 	/** @since 8.1 */
 	public static final int SEMANTIC_INVALID_STRUCTURED_BINDING_INITIALIZER = BINDING_INVALID_STRUCTURED_BINDING_INITIALIZER;
+	/** @since 8.4 */
+	public static final int SEMANTIC_INVALID_TEMPLATE_INSTANTIATION = BINDING_INVALID_TEMPLATE_INSTANTIATION;
 
 	/**
 	 * @deprecated There may be additional problems.

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/ISemanticProblem.java

@@ -39,6 +39,8 @@ public interface ISemanticProblem {
 	int BINDING_NO_CLASS = 16;
 	/** @since 8.1 */
 	int BINDING_INVALID_STRUCTURED_BINDING_INITIALIZER = 17;
+	/** @since 8.4 */
+	int BINDING_INVALID_TEMPLATE_INSTANTIATION = 18;
 
 	int TYPE_NO_NAME = 10000;
 	int TYPE_UNRESOLVED_NAME = 10001;

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

@@ -3103,10 +3103,17 @@ public static IBinding resolveFunction(LookupData data, ICPPFunction[] fns, bool
 		ICPPFunction[] tmp = selectByArgumentCount(data, fns);
 		if (tmp.length == 0 || tmp[0] == null)
 			return new ProblemBinding(lookupName, lookupPoint, IProblemBinding.SEMANTIC_NAME_NOT_FOUND, fns);
+		int nbBeforeInstantiate = tmp.length;
 		tmp = CPPTemplates.instantiateForFunctionCall(tmp, data.getTemplateArguments(), Arrays.asList(argTypes),
 				Arrays.asList(data.getFunctionArgumentValueCategories()), data.argsContainImpliedObject);
-		if (tmp.length == 0 || tmp[0] == null)
-			return new ProblemBinding(lookupName, lookupPoint, IProblemBinding.SEMANTIC_NAME_NOT_FOUND, fns);
+		if (tmp.length == 0 || tmp[0] == null) {
+			// All candidates were failed template instantiations
+			if (nbBeforeInstantiate == fns.length)
+				return new ProblemBinding(lookupName, lookupPoint,
+						IProblemBinding.SEMANTIC_INVALID_TEMPLATE_INSTANTIATION, fns);
+			else
+				return new ProblemBinding(lookupName, lookupPoint, IProblemBinding.SEMANTIC_NAME_NOT_FOUND, fns);
+		}
 
 		int viableCount = 0;
 		for (IFunction f : tmp) {