Allow disambiguating class constructor definition followed by semicolon

In this case member variable declaration would be longer (including
trailing semicolon) but it is not valid since a class C shall not contain
a non-static member of class C.

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

@@ -11559,4 +11559,14 @@ public class AST2TemplateTests extends AST2CPPTestBase {
 	public void testResolveFunctionTemplateInDeferredBaseArg() throws Exception {
 		parseAndCheckBindings();
 	}
+
+	//	template<typename T>
+	//	struct S {
+	//		S(T) {};
+	//	};
+	//
+	//	S<int> s(1);
+	public void testRecognizeConstructorWithSemicolonAfterBody() throws Exception {
+		parseAndCheckImplicitNameBindings();
+	}
 }

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

@@ -1702,6 +1702,9 @@ public abstract class AbstractGNUSourceCodeParser implements ISourceCodeParser {
 				&& LTcatchEOF(expectedBracketOffset + 1) == IToken.tIDENTIFIER;
 	}
 
+	protected abstract boolean maybeDeclaresNonStaticMemberOfSameClass(final DeclarationOptions option,
+			final IASTDeclSpecifier declSpec, final IASTDeclarator dtor);
+
 	/**
 	 * Parses for two alternatives of a declspec sequence followed by a initDeclarator.
 	 * A second alternative is accepted only, if it ends at the same point of the first alternative. Otherwise the
@@ -1770,10 +1773,16 @@ public abstract class AbstractGNUSourceCodeParser implements ISourceCodeParser {
 			return result.set(declspec1, dtor1, dtorMark1);
 		}
 
+		// [class.mem] "... In particluar, a class C shall not contain a non-static member of class C"
+		// If type name in first variant matches current class name, disambiguate it later too;
+		// this allows to handle the following case where constructor declaration is shorter
+		// than variable declaration with initializer list
+		//     template<typename T> class S { S(T){}; }
 		final IToken end2 = mark();
-		if (end1 == end2) {
+		if (end1 == end2 || maybeDeclaresNonStaticMemberOfSameClass(option, declspec1, dtor1)) {
 			return result.set(declspec1, dtor1, declspec2, dtor2);
 		}
+
 		if (end1.getEndOffset() > end2.getEndOffset()) {
 			backup(end1);
 			return result.set(declspec1, dtor1, dtorMark1);

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/c/GNUCSourceParser.java

@@ -2224,4 +2224,10 @@ public class GNUCSourceParser extends AbstractGNUSourceCodeParser {
 			IASTAlignmentSpecifier typeId) {
 		return new CASTAmbiguousAlignmentSpecifier(expression, typeId);
 	}
+
+	@Override
+	protected boolean maybeDeclaresNonStaticMemberOfSameClass(final DeclarationOptions option,
+			final IASTDeclSpecifier declSpec, final IASTDeclarator dtor) {
+		return false;
+	}
 }

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

@@ -4256,6 +4256,22 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 		return dtor;
 	}
 
+	@Override
+	protected boolean maybeDeclaresNonStaticMemberOfSameClass(final DeclarationOptions option,
+			final IASTDeclSpecifier declSpec, final IASTDeclarator dtor) {
+		if (option == DeclarationOptions.CPP_MEMBER && currentClassName != null
+				&& declSpec.getStorageClass() != IASTDeclSpecifier.sc_static && dtor != null
+				&& dtor.getPointerOperators().length == 0
+				&& declSpec instanceof ICPPASTNamedTypeSpecifier namedTypeSpec) {
+			IASTName name = namedTypeSpec.getName();
+			if (CharArrayUtils.equals(name.getLookupKey(), currentClassName)) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	/**
 	 * Tries to detect illegal versions of declarations
 	 */