fix usage of local_protect()

closes #278

src/altrep/mod.rs

@@ -34,7 +34,7 @@ pub(crate) fn create_altrep_instance<T: IntoExtPtrSexp>(
     class_name: &'static str,
 ) -> crate::Result<SEXP> {
     let sexp = x.into_external_pointer().0;
-    local_protect(sexp);
+    let _sexp_guard = local_protect(sexp);
 
     let catalogue_mutex = ALTREP_CLASS_CATALOGUE.get().ok_or(crate::Error::new(
         "ALTREP_CLASS_CATALOGUE is not initialized",
@@ -47,7 +47,7 @@ pub(crate) fn create_altrep_instance<T: IntoExtPtrSexp>(
         .ok_or(crate::Error::new("Failed to get the ALTREP class"))?;
 
     let altrep = unsafe { R_new_altrep(*class, sexp, R_NilValue) };
-    local_protect(altrep);
+    let _altrep_guard = local_protect(altrep);
 
     unsafe { MARK_NOT_MUTABLE(altrep) };
 

src/eval.rs

@@ -49,7 +49,7 @@ pub fn eval_parse_text<T: AsRef<str>>(text: T) -> crate::error::Result<EvalResul
 
     unsafe {
         let charsxp = str_to_charsxp(text.as_ref())?;
-        local_protect(charsxp);
+        let _charsxp_guard = local_protect(charsxp);
         let text_sexp = crate::unwind_protect(|| savvy_ffi::Rf_ScalarString(charsxp))?;
 
         // According to WRE (https://cran.r-project.org/doc/manuals/r-release/R-exts.html#Parsing-R-code-from-C),
@@ -76,7 +76,7 @@ pub fn eval_parse_text<T: AsRef<str>>(text: T) -> crate::error::Result<EvalResul
         let parsed = unwind_protect(|| {
             savvy_ffi::R_ParseVector(text_sexp, -1, parse_status.as_ptr(), R_NilValue)
         })?;
-        local_protect(parsed);
+        let _parsed_guard = local_protect(parsed);
 
         if parse_status.get() != savvy_ffi::ParseStatus_PARSE_OK {
             return Err(crate::error::Error::InvalidRCode(text.as_ref().to_string()));

src/protect.rs

@@ -78,7 +78,7 @@ pub fn insert_to_preserved_list(obj: SEXP) -> SEXP {
         }
 
         // Protect the object until the operation finishes
-        local_protect(obj);
+        let _obj_guard = local_protect(obj);
 
         let preserved = PRESERVED_LIST.get_or_init(|| {
             let r = Rf_cons(R_NilValue, R_NilValue);
@@ -87,7 +87,7 @@ pub fn insert_to_preserved_list(obj: SEXP) -> SEXP {
         });
         let token = Rf_cons(preserved.0, CDR(preserved.0));
 
-        local_protect(token);
+        let _token_guard = local_protect(token);
 
         SET_TAG(token, obj);
         SETCDR(preserved.0, token);

src/sexp/complex.rs

@@ -199,7 +199,7 @@ impl OwnedComplexSexp {
                 // truncated to the actual length at last.
 
                 let inner = crate::alloc_vector(CPLXSXP, upper as _)?;
-                local_protect(inner);
+                let _inner_guard = local_protect(inner);
                 let raw = unsafe { COMPLEX(inner) };
 
                 let mut last_index = 0;

src/sexp/external_pointer.rs

@@ -60,7 +60,7 @@ pub trait IntoExtPtrSexp: Sized {
             let external_pointer =
                 R_MakeExternalPtr(ptr as *mut std::os::raw::c_void, R_NilValue, R_NilValue);
 
-            local_protect(external_pointer);
+            let _external_pointer_guard = local_protect(external_pointer);
 
             // Use R_RegisterCFinalizerEx(..., TRUE) instead of
             // R_RegisterCFinalizer() in order to make the cleanup happen during

src/sexp/function.rs

@@ -125,7 +125,7 @@ impl FunctionSexp {
                 Rf_lcons(self.inner(), args.inner())
             };
 
-            local_protect(call);
+            let _call_guard = local_protect(call);
 
             // Note: here, probably the environment doesn't matter at all
             // because the first argument is the function, which preserves the

src/sexp/integer.rs

@@ -224,7 +224,7 @@ impl OwnedIntegerSexp {
     ///         let mut out = unsafe { OwnedIntegerSexp::new_without_init(2)? };
     ///         out[0] = value.x;
     ///         out[1] = value.y;
-    ///         
+    ///
     ///         Ok(out)
     ///     }
     /// }
@@ -285,7 +285,7 @@ impl OwnedIntegerSexp {
                 // truncated to the actual length at last.
 
                 let inner = crate::alloc_vector(INTSXP, upper as _)?;
-                local_protect(inner);
+                let _inner_guard = local_protect(inner);
                 let raw = unsafe { INTEGER(inner) };
 
                 let mut last_index = 0;

src/sexp/logical.rs

@@ -199,7 +199,7 @@ impl OwnedLogicalSexp {
     ///         let mut out = unsafe { OwnedLogicalSexp::new_without_init(2)? };
     ///         out.set_elt(0, value.x)?;
     ///         out.set_elt(1, value.y)?;
-    ///         
+    ///
     ///         Ok(out)
     ///     }
     /// }
@@ -259,7 +259,7 @@ impl OwnedLogicalSexp {
                 // truncated to the actual length at last.
 
                 let inner = crate::alloc_vector(LGLSXP, upper as _)?;
-                local_protect(inner);
+                let _inner_guard = local_protect(inner);
                 let raw = unsafe { LOGICAL(inner) };
 
                 let mut last_index = 0;

src/sexp/raw.rs

@@ -203,7 +203,7 @@ impl OwnedRawSexp {
     ///         let mut out = unsafe { OwnedRawSexp::new_without_init(2)? };
     ///         out[0] = value.x;
     ///         out[1] = value.y;
-    ///         
+    ///
     ///         Ok(out)
     ///     }
     /// }
@@ -264,7 +264,7 @@ impl OwnedRawSexp {
                 // truncated to the actual length at last.
 
                 let inner = crate::alloc_vector(RAWSXP, upper as _)?;
-                local_protect(inner);
+                let _inner_guard = local_protect(inner);
                 let raw = unsafe { RAW(inner) };
 
                 let mut last_index = 0;

src/sexp/real.rs

@@ -227,7 +227,7 @@ impl OwnedRealSexp {
     ///         let mut out = unsafe { OwnedRealSexp::new_without_init(2)? };
     ///         out[0] = value.x;
     ///         out[1] = value.y;
-    ///         
+    ///
     ///         Ok(out)
     ///     }
     /// }
@@ -288,7 +288,7 @@ impl OwnedRealSexp {
                 // truncated to the actual length at last.
 
                 let inner = crate::alloc_vector(REALSXP, upper as _)?;
-                local_protect(inner);
+                let _inner_guard = local_protect(inner);
                 let raw = unsafe { REAL(inner) };
 
                 let mut last_index = 0;

src/sexp/string.rs

@@ -186,7 +186,7 @@ impl OwnedStringSexp {
                 // truncated to the actual length at last.
 
                 let inner = crate::alloc_vector(STRSXP, upper as _)?;
-                local_protect(inner);
+                let _inner_guard = local_protect(inner);
 
                 let mut last_index = 0;
                 for (i, v) in iter.enumerate() {
@@ -260,7 +260,7 @@ impl OwnedStringSexp {
             // Note: unlike `new()`, this allocates a STRSXP after creating a
             // CHARSXP. So, the `CHARSXP` needs to be protected.
             let charsxp = str_to_charsxp(value.as_ref())?;
-            local_protect(charsxp);
+            let _charsxp_guard = local_protect(charsxp);
             crate::unwind_protect(|| savvy_ffi::Rf_ScalarString(charsxp))?
         };
         Self::new_from_raw_sexp(sexp, 1)