clang: fix empty-variadic calls

Author: nalgeon

internal/clang/function.go

@@ -342,6 +342,12 @@ func (g *Generator) emitVariadicArgs(w io.Writer, call *ast.CallExpr, sig *types
 	elemType := g.mapType(call, variadicParam.Type().(*types.Slice).Elem())
 	count := len(variadicArgs)
 
+	if count == 0 {
+		// No variadic args: emit a nil slice.
+		fmt.Fprint(w, "(so_Slice){0}")
+		return
+	}
+
 	fmt.Fprintf(w, "(so_Slice){(%s[%d]){", elemType, count)
 	targetType := variadicParam.Type().(*types.Slice).Elem()
 	for i, arg := range variadicArgs {

internal/clang/struct.go

@@ -296,6 +296,11 @@ func (g *Generator) emitMethodCallArgs(w io.Writer, sel *ast.SelectorExpr, call
 		elemType := g.mapType(sel, variadicParam.Type().(*types.Slice).Elem())
 		count := len(variadicArgs)
 		targetType := variadicParam.Type().(*types.Slice).Elem()
+		if count == 0 {
+			// No variadic args: emit a nil slice.
+			fmt.Fprintf(w, ", %s(so_Slice){0}%s", lparen, rparen)
+			return
+		}
 		fmt.Fprintf(w, ", %s(so_Slice){(%s[%d]){", lparen, elemType, count)
 		for i, arg := range variadicArgs {
 			if i > 0 {