Give the branch access expression type some meat.

In the ivl_target API, the IVL_EX_BACCESS expression type gets some meat,
specifically references to the branch it accesses and the the nature to
be accessed on that branch.

ivl_target.h

@@ -729,12 +729,16 @@ extern unsigned ivl_expr_lineno(ivl_expr_t net);
 
   /* IVL_EX_NUMBER */
 extern const char* ivl_expr_bits(ivl_expr_t net);
+  /* IVL_EX_BACCESS */
+extern ivl_branch_t ivl_expr_branch(ivl_expr_t net);
   /* IVL_EX_UFUNC */
 extern ivl_scope_t ivl_expr_def(ivl_expr_t net);
   /* IVL_EX_REALNUM */
 extern double ivl_expr_dvalue(ivl_expr_t net);
   /* IVL_EX_SIGNAL, IVL_EX_SFUNC, IVL_EX_VARIABLE */
 extern const char* ivl_expr_name(ivl_expr_t net);
+  /* IVL_EX_BACCESS */
+extern ivl_nature_t ivl_expr_nature(ivl_expr_t net);
   /* IVL_EX_BINARY IVL_EX_UNARY */
 extern char        ivl_expr_opcode(ivl_expr_t net);
   /* IVL_EX_BINARY  IVL_EX_UNARY, IVL_EX_MEMORY IVL_EX_TERNARY */

ivl_target_priv.h

@@ -20,6 +20,7 @@
  */
 
 # include  <inttypes.h>
+# include  <vector>
 
 /*
 * This header has declarations related to the ivl_target.h API that
@@ -47,7 +48,7 @@ class ivl_discipline_s;
 struct ivl_island_s {
       ivl_discipline_s*discipline;
 	// user accessible flags. They are initially false, always.
-      vector<bool> flags;
+      std::vector<bool> flags;
 };
 
 #endif

netlist.h

@@ -32,6 +32,7 @@
 # include  <set>
 # include  <utility>
 # include  "ivl_target.h"
+# include  "ivl_target_priv.h"
 # include  "pform_types.h"
 # include  "config.h"
 # include  "verinum.h"
@@ -184,10 +185,15 @@ class NetBranch  : public NetPins, public IslandBranch {
 	// If the branch is named, this returns the name.
       perm_string name() const { return name_; }
 
+      ivl_branch_s* target_obj() const { return &target_obj_; }
+
       void dump(ostream&, unsigned) const;
 
     private:
       perm_string name_;
+
+      mutable ivl_branch_s target_obj_;
+
 	// The design class uses this member to list the branches.
       friend class Design;
       NetBranch*next_;
@@ -3007,6 +3013,9 @@ class NetEAccess : public NetExpr {
       explicit NetEAccess(NetBranch*br, ivl_nature_t nat);
       ~NetEAccess();
 
+      ivl_nature_t get_nature() const { return nature_; }
+      NetBranch*   get_branch() const { return branch_; }
+
       virtual ivl_variable_type_t expr_type() const;
       virtual void dump(ostream&) const;
 

t-dll-api.cc

@@ -261,6 +261,12 @@ extern "C" const char* ivl_expr_bits(ivl_expr_t net)
       return net->u_.number_.bits_;
 }
 
+extern "C" ivl_branch_t ivl_expr_branch(ivl_expr_t net)
+{
+      assert(net && (net->type_ == IVL_EX_BACCESS));
+      return net->u_.branch_.branch;
+}
+
 extern "C" ivl_scope_t ivl_expr_def(ivl_expr_t net)
 {
       assert(net);
@@ -299,6 +305,12 @@ extern "C" const char* ivl_expr_name(ivl_expr_t net)
       return 0;
 }
 
+extern "C" ivl_nature_t ivl_expr_nature(ivl_expr_t net)
+{
+      assert(net && (net->type_ == IVL_EX_BACCESS));
+      return net->u_.branch_.nature;
+}
+
 extern "C" char ivl_expr_opcode(ivl_expr_t net)
 {
       assert(net);

t-dll-expr.cc

@@ -160,6 +160,9 @@ void dll_target::expr_access_func(const NetEAccess*net)
       expr_->lineno = net->get_lineno();
       expr_->width_ = 1;
       expr_->signed_= 1;
+
+      expr_->u_.branch_.branch = net->get_branch()->target_obj();
+      expr_->u_.branch_.nature = net->get_nature();
 }
 
 void dll_target::expr_binary(const NetEBinary*net)

t-dll.cc

@@ -780,7 +780,7 @@ void dll_target::make_const_delays_(struct ivl_net_const_s*obj,
 
 bool dll_target::branch(const NetBranch*net)
 {
-      struct ivl_branch_s*obj = new struct ivl_branch_s;
+      struct ivl_branch_s*obj = net->target_obj();
       ivl_assert(*net, net->pin_count() == 2);
 
       assert(net->pin(0).nexus()->t_cookie());

t-dll.h

@@ -232,6 +232,11 @@ struct ivl_expr_s {
 		  ivl_expr_t rig_;
 	    } binary_;
 
+	    struct {
+		  ivl_branch_t branch;
+		  ivl_nature_t nature;
+	    } branch_;
+
 	    struct {
 		  unsigned   rept;
 		  unsigned   parms;