Blocking assignment nearly working

tgt-vhdl/expr.cc

@@ -46,7 +46,7 @@ static vhdl_expr *translate_signal(ivl_expr_t e)
 
    const char *renamed = get_renamed_signal(sig).c_str();
    
-   const vhdl_decl *decl = ent->get_arch()->get_decl(renamed);
+   const vhdl_decl *decl = ent->get_arch()->get_decl(strip_var(renamed));
    assert(decl);
 
    vhdl_type *type = new vhdl_type(*decl->get_type());

tgt-vhdl/process.cc

@@ -32,11 +32,40 @@
 typedef std::set<std::string> string_set_t;
 static string_set_t g_assign_vars;
 
-void blocking_assign_to(vhdl_process *proc, std::string var)
+void blocking_assign_to(vhdl_process *proc, ivl_signal_t sig)
 {
+   std::string var(get_renamed_signal(sig));
+   
    std::cout << "blocking_assign_to " << var << std::endl;
+
+   if (g_assign_vars.find(var) == g_assign_vars.end()) {
+      // This is the first time a non-blocking assignment
+      // has been made to this signal: create a variable
+      // to shadow it.
+
+      vhdl_decl *decl = proc->get_parent()->get_decl(var);
+      assert(decl);
+      vhdl_type *type = new vhdl_type(*decl->get_type());
+
+      var += "_Var";
+      proc->add_decl(new vhdl_var_decl(var.c_str(), type));
+
+      rename_signal(sig, var);
+      g_assign_vars.insert(var);
+   }
 }
 
+/*
+ * Remove _Var from the end of a string, if it is present.
+ */
+std::string strip_var(const std::string &str)
+{
+   std::string result(str);
+   size_t pos = result.find("_Var");
+   if (pos != std::string::npos)
+      result.erase(pos, 4);
+   return result;
+}
 
 /*
  * Convert a Verilog process to VHDL and add it to the architecture

tgt-vhdl/stmt.cc

@@ -250,8 +250,6 @@ static int draw_assign(vhdl_process *proc, stmt_container *container,
    if ((sig = ivl_lval_sig(lval))) {
       const std::string &signame = get_renamed_signal(sig);
 
-      blocking_assign_to(proc, signame);
-
       vhdl_decl *decl = proc->get_decl(signame);
       assert(decl);
 
@@ -266,8 +264,13 @@ static int draw_assign(vhdl_process *proc, stmt_container *container,
          decl->set_initial(rhs);
       }
       else {
+         blocking_assign_to(proc, sig);
+
+         // The signal may have been renamed by the above call
+         const std::string &renamed = get_renamed_signal(sig);
+         
          // The type here can be null as it is never actually needed
-         vhdl_var_ref *lval_ref = new vhdl_var_ref(signame.c_str(), NULL);
+         vhdl_var_ref *lval_ref = new vhdl_var_ref(renamed.c_str(), NULL);
          
          vhdl_assign_stmt *assign = new vhdl_assign_stmt(lval_ref, rhs);
          container->add_stmt(assign);

tgt-vhdl/vhdl_target.h

@@ -31,7 +31,8 @@ void rename_signal(ivl_signal_t sig, const std::string &renamed);
 const vhdl_entity *find_entity_for_signal(ivl_signal_t sig);
 const std::string &get_renamed_signal(ivl_signal_t sig);
 
-void blocking_assign_to(vhdl_process *proc, std::string var);
+void blocking_assign_to(vhdl_process *proc, ivl_signal_t sig);
+std::string strip_var(const std::string &str);
 
 
 #endif /* #ifndef INC_VHDL_TARGET_H */