give module bounds a better respect for dynamic predicates

src/prolog/machine/compile.rs

@@ -216,14 +216,7 @@ impl ClauseCodeGenerator {
                 continue;
             }
 
-            if let Some(info) = wam.indices.dynamic_code_dir.get(&(name.clone(), arity)) {
+            wam.check_dynamic_clause_overwrite(name.clone(), arity)?;
-                if info.module_src != name.owning_module() {
-                    let err_str = format!("{}/{}", name.as_str(), arity);
-                    let err_str = clause_name!(err_str, wam.indices.atom_tbl());
-
-                    return Err(SessionError::CannotOverwriteDynamicClause(err_str));
-                }
-            }
 
             let predicate = Predicate(heads_and_tails.into_iter().map(|(head, tail)| {
                 let clause = Term::Clause(Cell::default(), clause_name!("clause"),

src/prolog/machine/mod.rs

@@ -101,8 +101,13 @@ impl SubModuleUser for IndexStore {
         }
     }
 
-    fn remove_code_index(&mut self, key: PredicateKey) {
+    fn remove_code_index(&mut self, key: PredicateKey)
+    {
         self.code_dir.remove(&key);
+
+        if self.dynamic_code_dir.contains_key(&key) {
+            self.dynamic_code_dir.remove(&key);
+        }
     }
 
     fn insert_dir_entry(&mut self, name: ClauseName, arity: usize, idx: ModuleCodeIndex)
@@ -208,6 +213,21 @@ impl Machine {
         self.machine_st.flags
     }
 
+    pub fn check_dynamic_clause_overwrite(&self, name: ClauseName, arity: usize)
+                                          -> Result<(), SessionError>
+    {
+        if let Some(info) = self.indices.dynamic_code_dir.get(&(name.clone(), arity)) {
+            if info.module_src != name.owning_module() {
+                let err_str = format!("{}/{}", name.as_str(), arity);
+                let err_str = clause_name!(err_str, self.indices.atom_tbl());
+
+                return Err(SessionError::CannotOverwriteDynamicClause(err_str));
+            }
+        }
+
+        Ok(())
+    }
+
     pub fn check_toplevel_code(&self, indices: &IndexStore) -> Result<(), SessionError>
     {
         for (key, idx) in &indices.code_dir {
@@ -222,6 +242,8 @@ impl Machine {
                 }
             };
 
+            self.check_dynamic_clause_overwrite(key.0.clone(), key.1)?;
+            
             if let Some(ref existing_idx) = self.indices.code_dir.get(&key) {
                 // ensure we don't try to overwrite an existing predicate from a different module.
                 if !existing_idx.is_undefined() && !idx.is_undefined() {

src/prolog/machine/modules.rs

@@ -84,7 +84,6 @@ pub trait SubModuleUser
 
                     self.remove_code_index((name.clone(), arity));
 
-
                     // remove or respecify ops.
                     if arity == 2 {
                         if let Some((_, _, mod_name)) = self.op_dir().get(&(name.clone(), Fixity::In)).cloned()
@@ -115,7 +114,8 @@ pub trait SubModuleUser
     }
 
     // returns true on successful import.
-    fn import_decl(&mut self, name: ClauseName, arity: usize, submodule: &Module) -> bool
+    fn import_decl(&mut self, name: ClauseName, arity: usize, submodule: &Module)
+                   -> bool
     {
         let name = name.defrock_brackets();
         let mut found_op = false;
@@ -172,8 +172,7 @@ pub fn use_qualified_module<User>(user: &mut User, submodule: &Module, exports:
     Ok(())
 }
 
-pub fn use_module<User: SubModuleUser>(user: &mut User, submodule: &Module)
+pub fn use_module<User: SubModuleUser>(user: &mut User, submodule: &Module) -> Result<(), SessionError>
-                                       -> Result<(), SessionError>
 {
     for (name, arity) in submodule.module_decl.exports.iter().cloned() {
         if !user.import_decl(name, arity, submodule) {