Add support for implict this in class methods

PExpr.h

@@ -936,7 +936,8 @@ class PECallFunction : public PExpr {
       NetExpr*elaborate_expr_pkg_(Design*des, NetScope*scope,
 				  unsigned expr_wid, unsigned flags)const;
       NetExpr*elaborate_expr_method_(Design*des, NetScope*scope,
-				     unsigned expr_wid) const;
+				     unsigned expr_wid,
+				     bool add_this_flag = false) const;
 #if 0
       NetExpr*elaborate_expr_string_method_(Design*des, NetScope*scope) const;
       NetExpr*elaborate_expr_enum_method_(Design*des, NetScope*scope,

Statement.h

@@ -224,7 +224,8 @@ class PCallTask  : public Statement {
       NetProc* elaborate_sys(Design*des, NetScope*scope) const;
       NetProc* elaborate_usr(Design*des, NetScope*scope) const;
 
-      NetProc*elaborate_method_(Design*des, NetScope*scope) const;
+      NetProc*elaborate_method_(Design*des, NetScope*scope,
+                                bool add_this_flag = false) const;
       NetProc*elaborate_function_(Design*des, NetScope*scope) const;
 
       NetProc*elaborate_build_call_(Design*des, NetScope*scope,

elab_expr.cc

@@ -2064,11 +2064,24 @@ NetExpr* PECallFunction::elaborate_expr(Design*des, NetScope*scope,
 	    des->errors += 1;
 	    return 0;
       }
-      ivl_assert(*this, def);
 
+      ivl_assert(*this, def);
       NetScope*dscope = def->scope();
       ivl_assert(*this, dscope);
 
+       /* In SystemVerilog a method calling another method in the
+        * current class needs to be elaborated as a method with an
+        * implicit this added.  */
+      if (gn_system_verilog() && (path_.size() == 1)) {
+           const NetScope *c_scope = scope->get_class_scope();
+           if (c_scope && (c_scope == dscope->get_class_scope())) {
+                 NetExpr*tmp = elaborate_expr_method_(des, scope, expr_wid,
+		                                      true);
+                 assert(tmp);
+                 return tmp;
+           }
+      }
+
       bool need_const = NEED_CONST & flags;
 
         // It is possible to get here before the called function has been
@@ -2262,17 +2275,22 @@ unsigned PECallFunction::elaborate_arguments_(Design*des, NetScope*scope,
 }
 
 NetExpr* PECallFunction::elaborate_expr_method_(Design*des, NetScope*scope,
-						unsigned expr_wid) const
+						unsigned expr_wid,
+						bool add_this_flag) const
 {
       pform_name_t use_path = path_;
       perm_string method_name = peek_tail_name(use_path);
       use_path.pop_back();
 
+	/* Add the implicit this reference when requested. */
+      if (add_this_flag) {
+	    assert(use_path.empty());
+	    use_path.push_front(name_component_t(perm_string::literal("@")));
+      }
+
 	// If there is no object to the left of the method name, then
 	// give up on the idea of looking for an object method.
-      if (use_path.empty()) {
+      if (use_path.empty()) return 0;
-	    return 0;
-      }
 
       NetNet *net = 0;
       const NetExpr *par;

elaborate.cc

@@ -3439,6 +3439,17 @@ NetProc* PCallTask::elaborate_usr(Design*des, NetScope*scope) const
       }
       assert(def);
 
+	/* In SystemVerilog a method calling another method in the
+	 * current class needs to be elaborated as a method with an
+	 * implicit this added.  */
+      if (gn_system_verilog() && (path_.size() == 1)) {
+	    const NetScope *c_scope = scope->get_class_scope();
+	    if (c_scope && (c_scope == task->get_class_scope())) {
+		  NetProc *tmp = elaborate_method_(des, scope, true);
+		  assert(tmp);
+		  return tmp;
+	    }
+      }
 
       unsigned parm_count = def->port_count();
 
@@ -3490,7 +3501,8 @@ NetProc* PCallTask::elaborate_sys_task_method_(Design*des, NetScope*scope,
       return sys;
 }
 
-NetProc* PCallTask::elaborate_method_(Design*des, NetScope*scope) const
+NetProc* PCallTask::elaborate_method_(Design*des, NetScope*scope,
+                                      bool add_this_flag) const
 {
       pform_name_t use_path = path_;
       perm_string method_name = peek_tail_name(use_path);
@@ -3501,6 +3513,12 @@ NetProc* PCallTask::elaborate_method_(Design*des, NetScope*scope) const
       NetEvent *eve;
       const NetExpr *ex1, *ex2;
 
+	/* Add the implicit this reference when requested. */
+      if (add_this_flag) {
+	    assert(use_path.empty());
+	    use_path.push_front(name_component_t(perm_string::literal("@")));
+      }
+
 	// There is no signal to search for so this cannot be a method.
       if (use_path.empty()) return 0;
 

net_scope.cc

@@ -691,6 +691,32 @@ const NetScope* NetScope::child(const hname_t&name) const
 	    return cur->second;
 }
 
+/* Helper function to see if the given scope is defined in a class and if
+ * so return the class scope. */
+const NetScope* NetScope::get_class_scope() const
+{
+      const NetScope*scope = this;
+      while (scope) {
+	    switch(scope->type()) {
+		case NetScope::CLASS:
+		  return scope;
+		case NetScope::TASK:
+		case NetScope::FUNC:
+		case NetScope::BEGIN_END:
+		case NetScope::FORK_JOIN:
+		  break;
+		case NetScope::MODULE:
+		case NetScope::GENBLOCK:
+		case NetScope::PACKAGE:
+		  return 0;
+		default:
+		  assert(0);
+	    }
+	    scope = scope->parent();
+      }
+      return scope;
+}
+
 const NetScope* NetScope::child_byname(perm_string name) const
 {
       hname_t hname (name);

netlist.h

@@ -995,6 +995,9 @@ class NetScope : public Definitions, public Attrib {
       const NetScope* parent() const { return up_; }
       const NetScope* child(const hname_t&name) const;
 
+	/* A helper function to find the enclosing class scope. */
+      const NetScope* get_class_scope() const;
+
 	// Look for a child scope by name. This ignores the number
 	// part of the child scope name, so there may be multiple
 	// matches. Only return one. This function is only really