More VHDL naming fixes

This handles the cases where:
    * Instance names contain leading/trailing underscores
    * Instance names contain consecutive underscores
    * Module names contain consecutive underscores
    * Module names contain leading/trailing underscores
	* Ports may be inconsistently renamed

tgt-vhdl/scope.cc

@@ -376,6 +376,28 @@ static void declare_logic(vhdl_arch *arch, ivl_scope_t scope)
       draw_logic(arch, ivl_scope_log(scope, i)); 
 }
 
+// Replace consecutive underscores with a single underscore
+static void replace_consecutive_underscores(string& str)
+{
+   size_t pos = str.find("__");
+   while (pos != string::npos) {
+      str.replace(pos, 2, "_");
+      pos = str.find("__");
+   }
+}
+
+// Return a valid VHDL name for a Verilog module
+string valid_entity_name(const string& module_name)
+{
+   string name(module_name);
+   replace_consecutive_underscores(name);
+   if (name[0] == '_')
+      name = "Mod" + name;
+   if (*name.rbegin() == '_')
+      name += "Mod";
+   return name;
+}
+
 // Make sure a signal name conforms to VHDL naming rules.
 string make_safe_name(ivl_signal_t sig)
 {
@@ -391,11 +413,7 @@ string make_safe_name(ivl_signal_t sig)
       base += "Sig";
 
    // Can't have two consecutive underscores
-   size_t pos = base.find("__");
-   while (pos != string::npos) {
-      base.replace(pos, 2, "_");
-      pos = base.find("__");
-   }
+   replace_consecutive_underscores(base);
    
    // A signal name may not be the same as a component name
    if (find_entity(base) != NULL)
@@ -446,16 +464,9 @@ static void avoid_name_collision(string& name, vhdl_scope* scope)
    }
 }
 
-/*
- * Declare all signals and ports for a scope.
- */
-static void declare_signals(vhdl_entity *ent, ivl_scope_t scope)
+// Declare a single signal in a scope
+static void declare_one_signal(vhdl_entity *ent, ivl_signal_t sig)
 {
-   debug_msg("Declaring signals in scope type %s", ivl_scope_tname(scope));
-   
-   int nsigs = ivl_scope_sigs(scope);
-   for (int i = 0; i < nsigs; i++) {
-      ivl_signal_t sig = ivl_scope_sig(scope, i);      
    remember_signal(sig, ent->get_arch()->get_scope());
 
    string name(make_safe_name(sig));
@@ -552,6 +563,29 @@ static void declare_signals(vhdl_entity *ent, ivl_scope_t scope)
    default:
       assert(false);
    }
+}
+
+// Declare all signals and ports for a scope.
+// This is done in two phases: first the ports are added then then
+// internal signals. Making two passes like this ensures ports get
+// first pick of names when there is a collision.
+static void declare_signals(vhdl_entity *ent, ivl_scope_t scope)
+{
+   debug_msg("Declaring signals in scope type %s", ivl_scope_tname(scope));
+   
+   int nsigs = ivl_scope_sigs(scope);
+   for (int i = 0; i < nsigs; i++) {
+      ivl_signal_t sig = ivl_scope_sig(scope, i);      
+
+      if (ivl_signal_port(sig) != IVL_SIP_NONE)
+         declare_one_signal(ent, sig);
+   }
+   
+   for (int i = 0; i < nsigs; i++) {
+      ivl_signal_t sig = ivl_scope_sig(scope, i);      
+
+      if (ivl_signal_port(sig) == IVL_SIP_NONE)
+         declare_one_signal(ent, sig);
    }
 }
 
@@ -788,7 +822,7 @@ static void create_skeleton_entity_for(ivl_scope_t scope, int depth)
    assert(ivl_scope_type(scope) == IVL_SCT_MODULE);
 
    // The type name will become the entity name
-   const char *tname = ivl_scope_tname(scope);;
+   const string tname = valid_entity_name(ivl_scope_tname(scope));
    
    // Verilog does not have the entity/architecture distinction
    // so we always create a pair and associate the architecture
@@ -1022,6 +1056,15 @@ static int draw_hierarchy(ivl_scope_t scope, void *_parent)
       if (loc != string::npos)
          inst_name.erase(loc, 1);
 
+      // No leading or trailing underscores
+      if (inst_name[0] == '_')
+         inst_name = "Inst" + inst_name;
+      if (*inst_name.rbegin() == '_')
+         inst_name += "Inst";
+
+      // Can't have two consecutive underscores
+      replace_consecutive_underscores(inst_name);
+
       // Make sure the name doesn't collide with anything we've
       // already declared
       avoid_name_collision(inst_name, parent_arch->get_scope());

tgt-vhdl/state.cc

@@ -170,7 +170,7 @@ vhdl_entity* find_entity(const ivl_scope_t scope)
 {
    assert(ivl_scope_type(scope) == IVL_SCT_MODULE);
 
-   return find_entity(ivl_scope_tname(scope));
+   return find_entity(valid_entity_name(ivl_scope_tname(scope)));
 }
 
 // Add an entity/architecture pair to the list of entities to emit.

tgt-vhdl/vhdl_syntax.cc

@@ -100,7 +100,7 @@ vhdl_scope *vhdl_scope::get_parent() const
    return parent_;
 }
 
-vhdl_entity::vhdl_entity(const char *name, vhdl_arch *arch, int depth__)
+vhdl_entity::vhdl_entity(const string& name, vhdl_arch *arch, int depth__)
    :  depth(depth__), name_(name), arch_(arch)
 {
    arch->get_scope()->set_parent(&ports_);

tgt-vhdl/vhdl_syntax.hh

@@ -806,7 +806,7 @@ private:
  */
 class vhdl_arch : public vhdl_element {
 public:
-   vhdl_arch(const char *entity, const char *name)
+   vhdl_arch(const string& entity, const string& name)
       : name_(name), entity_(entity) {}
    virtual ~vhdl_arch();
 
@@ -828,7 +828,7 @@ private:
  */
 class vhdl_entity : public vhdl_element {
 public:
-   vhdl_entity(const char *name, vhdl_arch *arch, int depth=0);
+   vhdl_entity(const string& name, vhdl_arch *arch, int depth=0);
    virtual ~vhdl_entity();
 
    void emit(std::ostream &of, int level=0) const;

tgt-vhdl/vhdl_target.h

@@ -28,6 +28,7 @@ ivl_design_t get_vhdl_design();
 vhdl_var_ref *nexus_to_var_ref(vhdl_scope *arch_scope, ivl_nexus_t nexus);
 vhdl_var_ref* readable_ref(vhdl_scope* scope, ivl_nexus_t nex);
 string make_safe_name(ivl_signal_t sig);
+string valid_entity_name(const string& module_name);
    
 int draw_stask_display(vhdl_procedural *proc, stmt_container *container,
                        ivl_statement_t stmt, bool newline = true);