Fix R_UnboundValue NOTE

ChangeLog

@@ -1,3 +1,11 @@
+2026-03-29  Iñaki Ucar <iucar@fedoraproject.org>
+
+	* inst/include/Rcpp/api/meat/Rcpp_eval.h: Remove check for non-API
+	R_UnboundValue, which is never returned anyway from Rf_findFun
+	* inst/include/Rcpp/Function.h: Use alternative to R_UnboundValue
+	* inst/include/Rcpp/Promise.h: Idem
+	* inst/include/Rcpp/Environment.h: Idem + some refactoring
+
 2026-03-26  Iñaki Ucar <iucar@fedoraproject.org>
 
 	* inst/include/Rcpp/internal/r_vector.h: Use dataptr() again to avoid an

inst/include/Rcpp/Environment.h

@@ -2,7 +2,8 @@
 // Environment.h: Rcpp R/C++ interface class library -- access R environments
 //
 // Copyright (C) 2009-2013  Dirk Eddelbuettel and Romain François
-// Copyright (C) 2014-2026  Dirk Eddelbuettel, Romain François and Kevin Ushey
+// Copyright (C) 2014-2025  Dirk Eddelbuettel, Romain François and Kevin Ushey
+// Copyright (C) 2026       Dirk Eddelbuettel, Romain François, Kevin Ushey and Iñaki Ucar
 //
 // This file is part of Rcpp.
 //
@@ -95,20 +96,8 @@ namespace Rcpp{
          * @return a SEXP (possibly R_NilValue)
          */
         SEXP get(const std::string& name) const {
-            SEXP env = Storage::get__() ;
-            SEXP nameSym = Rf_install(name.c_str());
-#if R_VERSION < R_Version(4,5,0)
-            SEXP res = Rf_findVarInFrame( env, nameSym ) ;
-#else
-            SEXP res = R_getVarEx(nameSym, env, FALSE, R_UnboundValue);
-#endif
-            if( res == R_UnboundValue ) return R_NilValue ;
-
-            /* We need to evaluate if it is a promise */
-            if( TYPEOF(res) == PROMSXP){
-                res = internal::Rcpp_eval_impl( res, env ) ;  // #nocov
-            }
-            return res ;
+            Symbol nameSym = Rf_install(name.c_str());
+            return get(nameSym);
         }
 
         /**
@@ -122,16 +111,12 @@ namespace Rcpp{
             SEXP env = Storage::get__() ;
 #if R_VERSION < R_Version(4,5,0)
             SEXP res = Rf_findVarInFrame( env, name ) ;
+            if (res == R_UnboundValue) return R_NilValue;
+            if (TYPEOF(res) == PROMSXP)
+                res = internal::Rcpp_eval_impl(res, env);
 #else
-            SEXP res = R_getVarEx(name, env, FALSE, R_UnboundValue);
+            SEXP res = R_getVarEx(name, env, FALSE, R_NilValue);
 #endif
-
-            if( res == R_UnboundValue ) return R_NilValue ;
-
-            /* We need to evaluate if it is a promise */
-            if( TYPEOF(res) == PROMSXP){
-                res = internal::Rcpp_eval_impl( res, env ) ;
-            }
             return res ;
         }
 
@@ -144,21 +129,8 @@ namespace Rcpp{
          *
          */
         SEXP find( const std::string& name) const{
-            SEXP env = Storage::get__() ;
-            SEXP nameSym = Rf_install(name.c_str());
-#if R_VERSION < R_Version(4,5,0)
-            SEXP res = Rf_findVar( nameSym, env ) ;
-#else
-            SEXP res = R_getVarEx(nameSym, env, TRUE, R_UnboundValue);
-#endif
-
-            if( res == R_UnboundValue ) throw binding_not_found(name) ;
-
-            /* We need to evaluate if it is a promise */
-            if( TYPEOF(res) == PROMSXP){
-                res = internal::Rcpp_eval_impl( res, env ) ;
-            }
-            return res ;
+            Symbol nameSym = Rf_install(name.c_str());
+            return find(nameSym);
         }
 
         /**
@@ -171,19 +143,13 @@ namespace Rcpp{
             SEXP env = Storage::get__() ;
 #if R_VERSION < R_Version(4,5,0)
             SEXP res = Rf_findVar( name, env ) ;
+            if (res == R_UnboundValue) throw binding_not_found(name.c_str());
+            if (TYPEOF(res) == PROMSXP)
+                res = internal::Rcpp_eval_impl(res, env);
 #else
-            SEXP res = R_getVarEx(name, env, TRUE, R_UnboundValue);
+            SEXP res = R_getVarEx(name, env, TRUE, NULL);
+            if (res == NULL) throw binding_not_found(name.c_str());
 #endif
-            if( res == R_UnboundValue ) {
-                // Pass on the const char* to the RCPP_EXCEPTION_CLASS's
-                // const std::string& requirement
-                throw binding_not_found(name.c_str()) ;
-            }
-
-            /* We need to evaluate if it is a promise */
-            if( TYPEOF(res) == PROMSXP){
-                res = internal::Rcpp_eval_impl( res, env ) ;
-            }
             return res ;
         }
 
@@ -199,10 +165,11 @@ namespace Rcpp{
             SEXP nameSym = Rf_install(name.c_str());
 #if R_VERSION < R_Version(4,5,0)
             SEXP res = Rf_findVarInFrame( Storage::get__() , nameSym  ) ;
+            return res != R_UnboundValue;
 #else
-            SEXP res = R_getVarEx(nameSym, Storage::get__(), FALSE, R_UnboundValue);
+            SEXP res = R_getVarEx(nameSym, Storage::get__(), FALSE, NULL);
+            return res != NULL;
 #endif
-            return res != R_UnboundValue ;
         }
 
         /**

inst/include/Rcpp/Function.h

@@ -1,7 +1,8 @@
 
 // Function.h: Rcpp R/C++ interface class library -- functions (also primitives and builtins)
 //
-// Copyright (C) 2010 - 2026  Dirk Eddelbuettel and Romain Francois
+// Copyright (C) 2010 - 2025  Dirk Eddelbuettel and Romain Francois
+// Copyright (C) 2026         Dirk Eddelbuettel, Romain François and Iñaki Ucar
 //
 // This file is part of Rcpp.
 //
@@ -71,12 +72,13 @@ namespace Rcpp{
         Function_Impl(const std::string& name, const std::string& ns) {
 #if R_VERSION < R_Version(4,5,0)
             Shield<SEXP> env(Rf_findVarInFrame(R_NamespaceRegistry, Rf_install(ns.c_str())));
+            if (env == R_UnboundValue)
+                stop("there is no namespace called \"%s\"", ns);
 #else
-            Shield<SEXP> env(R_getVarEx(Rf_install(ns.c_str()), R_NamespaceRegistry, FALSE, R_UnboundValue));
-#endif
-            if (env == R_UnboundValue) {
+            Shield<SEXP> env(R_getVarEx(Rf_install(ns.c_str()), R_NamespaceRegistry, FALSE, R_NilValue));
+            if (env == R_NilValue)
                 stop("there is no namespace called \"%s\"", ns);
-            }
+#endif
             get_function(name, env);
         }
 

inst/include/Rcpp/Promise.h

@@ -2,7 +2,8 @@
 //
 // Promise.h: Rcpp R/C++ interface class library -- promises (PROMSXP)
 //
-// Copyright (C) 2010 - 2013 Dirk Eddelbuettel and Romain Francois
+// Copyright (C) 2010 - 2025 Dirk Eddelbuettel and Romain François
+// Copyright (C) 2026        Dirk Eddelbuettel, Romain François and Iñaki Ucar
 //
 // This file is part of Rcpp.
 //
@@ -48,13 +49,18 @@ namespace Rcpp{
          * Return the result of the PRVALUE macro on the promise
          */
         SEXP value() const{
-            SEXP val = PRVALUE( Storage::get__() ) ;
-            if( val == R_UnboundValue ) throw unevaluated_promise() ;
-            return val ;
+            if (!was_evaluated()) throw unevaluated_promise();
+            return PRVALUE(Storage::get__());
         }
 
         bool was_evaluated() const {
+#if R_VERSION < R_Version(4,6,0)
             return PRVALUE(Storage::get__()) != R_UnboundValue ;
+#else
+            SEXP env = environment();
+            R_BindingType_t bt = R_GetBindingType(Storage::get__(), env);
+            return bt != R_BindingTypeUnbound;
+#endif
         }
 
         /**

inst/include/Rcpp/api/meat/Rcpp_eval.h

@@ -1,5 +1,5 @@
 // Copyright (C) 2013 - 2025 Romain Francois
-// Copyright (C) 2026        Romain Francois and Dirk Eddelbuettel
+// Copyright (C) 2026        Romain Francois, Dirk Eddelbuettel and Iñaki Ucar
 //
 // This file is part of Rcpp.
 //
@@ -56,10 +56,6 @@ inline SEXP Rcpp_eval(SEXP expr, SEXP env) {
     // 'identity' function used to capture errors, interrupts
     Shield<SEXP> identity(Rf_findFun(::Rf_install("identity"), R_BaseNamespace));
 
-    if (identity == R_UnboundValue) {
-        stop("Failed to find 'base::identity()'");
-    }
-
     // define the evalq call -- the actual R evaluation we want to execute
     Shield<SEXP> evalqCall(Rf_lang3(::Rf_install("evalq"), expr, env));