From 89244e0f701025500e91b20f828318a3ed51e820 Mon Sep 17 00:00:00 2001
From: Martin Whitaker <icarus@martin-whitaker.me.uk>
Date: Wed, 6 Feb 2013 09:33:29 +0000
Subject: [PATCH] Add support for concatenation operations in constant
 functions.

Also fix a compiler crash when attempting to evaluate a function
which has no valid statement(s) (due to earlier compilation errors).
---
 eval_tree.cc     | 24 ++++++++++++++++--------
 net_func_eval.cc | 33 +++++++++++++++++++++++++++++++--
 netlist.h        |  4 ++++
 3 files changed, 51 insertions(+), 10 deletions(-)

diff --git a/eval_tree.cc b/eval_tree.cc
index 992f18175..fcecd9bea 100644
--- a/eval_tree.cc
+++ b/eval_tree.cc
@@ -1090,14 +1090,8 @@ NetEConst* NetEBShift::eval_arguments_(const NetExpr*l, const NetExpr*r) const
 
 NetEConst* NetEConcat::eval_tree()
 {
-      unsigned repeat_val = repeat();
       unsigned local_errors = 0;
 
-      if (debug_eval_tree) {
-	    cerr << get_fileline() << ": debug: Evaluating expression:"
-	         << *this << endl;
-      }
-
       unsigned gap = 0;
       for (unsigned idx = 0 ;  idx < parms_.size() ;  idx += 1) {
 
@@ -1141,6 +1135,14 @@ NetEConst* NetEConcat::eval_tree()
 
       if (local_errors > 0) return 0;
 
+      return eval_arguments_(parms_, gap);
+}
+
+NetEConst* NetEConcat::eval_arguments_(const vector<NetExpr*>&vals,
+                                       unsigned gap) const
+{
+      unsigned repeat_val = repeat();
+
 	// At this point, the "gap" is the width of a single repeat of
 	// the concatenation. The total width of the result is the gap
 	// times the repeat count.
@@ -1150,8 +1152,8 @@ NetEConst* NetEConcat::eval_tree()
 
       unsigned cur = 0;
       bool is_string_flag = true;
-      for (unsigned idx = parms_.size() ;  idx > 0 ;  idx -= 1) {
-	    NetEConst*expr = dynamic_cast<NetEConst*>(parms_[idx-1]);
+      for (unsigned idx = vals.size() ;  idx > 0 ;  idx -= 1) {
+	    const NetEConst*expr = dynamic_cast<NetEConst*>(vals[idx-1]);
 	    if (expr == 0)
 		  return 0;
 
@@ -1176,6 +1178,12 @@ NetEConst* NetEConcat::eval_tree()
       val.has_sign( this->has_sign() );
 
       NetEConst*res = new NetEConst(val);
+      ivl_assert(*this, res);
+      res->set_line(*this); 
+      if (debug_eval_tree) {
+	    cerr << get_fileline() << ": debug: Evaluated: "
+	         << *this << " --> " << *res << endl;
+      }
       return res;
 }
 
diff --git a/net_func_eval.cc b/net_func_eval.cc
index b156bdc1b..727d469cf 100644
--- a/net_func_eval.cc
+++ b/net_func_eval.cc
@@ -55,8 +55,10 @@ NetExpr* NetFuncDef::evaluate_function(const LineInfo&loc, const std::vector<Net
 	// fills in the context_map with local variables held by the scope.
       scope_->evaluate_function_find_locals(loc, context_map);
 
-	// Perform the evaluation
-      bool flag = statement_->evaluate_function(loc, context_map);
+	// Perform the evaluation. Note that if there were errors
+	// when compiling the function definition, we may not have
+	// a valid statement.
+      bool flag = statement_ && statement_->evaluate_function(loc, context_map);
 
 	// Extract the result...
       ptr = context_map.find(scope_->basename());
@@ -295,6 +297,33 @@ NetExpr* NetEBinary::evaluate_function(const LineInfo&loc,
       return res;
 }
 
+NetExpr* NetEConcat::evaluate_function(const LineInfo&loc,
+				    map<perm_string,NetExpr*>&context_map) const
+{
+      vector<NetExpr*>vals(parms_.size());
+      unsigned gap = 0;
+
+      unsigned valid_vals = 0;
+      for (unsigned idx = 0 ;  idx < parms_.size() ;  idx += 1) {
+            ivl_assert(*this, parms_[idx]);
+            vals[idx] = parms_[idx]->evaluate_function(loc, context_map);
+            if (vals[idx] == 0) continue;
+
+            gap += vals[idx]->expr_width();
+
+            valid_vals += 1;
+      }
+
+      NetExpr*res = 0;
+      if (valid_vals == parms_.size()) {
+            res = eval_arguments_(vals, gap);
+      }
+      for (unsigned idx = 0 ;  idx < vals.size() ;  idx += 1) {
+            delete vals[idx];
+      }
+      return res;
+}
+
 NetExpr* NetEConst::evaluate_function(const LineInfo&,
 				      map<perm_string,NetExpr*>&) const
 {
diff --git a/netlist.h b/netlist.h
index 904ec51f5..60034c049 100644
--- a/netlist.h
+++ b/netlist.h
@@ -3789,6 +3789,8 @@ class NetEConcat  : public NetExpr {
       virtual bool has_width() const;
       virtual NetEConcat* dup_expr() const;
       virtual NetEConst*  eval_tree();
+      virtual NetExpr* evaluate_function(const LineInfo&loc,
+					 std::map<perm_string,NetExpr*>&ctx) const;
       virtual NetNet*synthesize(Design*, NetScope*scope, NetExpr*root);
       virtual void expr_scan(struct expr_scan_t*) const;
       virtual void dump(ostream&) const;
@@ -3797,6 +3799,8 @@ class NetEConcat  : public NetExpr {
       std::vector<NetExpr*>parms_;
       unsigned repeat_;
       ivl_variable_type_t expr_type_;
+
+      NetEConst* eval_arguments_(const vector<NetExpr*>&vals, unsigned gap) const;
 };