Allow preempt LVS configuration

same_nets, equivalent_pins, same_circuits and same_device_classes
can now be given at the beginning of the LVS script. This will
simplify building universal scripts with the run specific part at
the beginning (one "load" section).

The price are somewhat less specific error messages when something
fails in these methods.

src/lvs/lvs/built-in-macros/_lvs_netter.rb

@@ -48,6 +48,7 @@ module LVS
 
     def initialize(engine)
       super
+      @comparer_config = []
     end
 
     def _make_data
@@ -161,6 +162,11 @@ module LVS
       nl = _ensure_two_netlists
       lvs_data.reference = nl[1]
 
+      # execute the configuration commands
+      @comparer_config.each do |cc|
+        cc.call
+      end
+
       lvs_data.compare(@comparer)
 
     end
@@ -217,6 +223,12 @@ module LVS
         n.is_a?(String) || n.is_a?(RBA::Net) || raise("Net arguments of 'same_nets' must be strings or Net objects")
       end
 
+      @comparer_config << lambda { self._same_nets(ca, a, cb, b) }
+
+    end
+
+    def _same_nets(ca, a, cb, b)
+
       ( nl_a, nl_b ) = _ensure_two_netlists
 
       if ca.is_a?(String)
@@ -234,13 +246,13 @@ module LVS
       if circuit_a && circuit_b
 
         if a.is_a?(String)
-          net_a = circuit_a.net_by_name(a) || raise("Not a valid net name in extracted netlist: #{a} (for circuit #{circuit_a})")
+          net_a = circuit_a.net_by_name(a) || raise("Not a valid net name in extracted netlist in 'same_nets': #{a} (for circuit #{circuit_a})")
         else
           net_a = a
         end
 
         if b.is_a?(String)
-          net_b = circuit_b.net_by_name(b) || raise("Not a valid net name in extracted netlist: #{b} (for circuit #{circuit_b})")
+          net_b = circuit_b.net_by_name(b) || raise("Not a valid net name in extracted netlist in 'same_nets': #{b} (for circuit #{circuit_b})")
         else
           net_b = b
         end
@@ -271,6 +283,12 @@ module LVS
 
       a.is_a?(String) || a == nil || b.is_a?(String) || b == nil || raise("Both arguments of 'same_circuits' need to be strings or nil")
 
+      @comparer_config << lambda { self._same_circuits(a, b) }
+
+    end
+
+    def _same_circuits(a, b)
+
       ( nl_a, nl_b ) = _ensure_two_netlists
 
       circuit_a = a && nl_a.circuit_by_name(a)
@@ -301,9 +319,15 @@ module LVS
 
       a.is_a?(String) || a == nil || b.is_a?(String) || b == nil || raise("Both arguments of 'same_device_classes' need to be strings or nil")
 
+      @comparer_config << lambda { self._same_device_classes(a, b) }
+
+    end
+
+    def _same_device_classes(a, b)
+
       ( nl_a, nl_b ) = _ensure_two_netlists
 
-      dc_a = a && (nl_a.device_class_by_name(a) || raise("Not a valid device class in extracted netlist: #{a}"))
+      dc_a = a && (nl_a.device_class_by_name(a) || raise("Not a valid device class in extracted netlist in 'same_device_class': #{a}"))
       dc_b = b && nl_b.device_class_by_name(b)
 
       # NOTE: a device class is allowed to be missing in the reference netlist because the
@@ -347,6 +371,12 @@ module LVS
           raise("All pin arguments of 'equivalent_pins' need to be strings or numbers")
       end
 
+      @comparer_config << lambda { self._equivalent_pins(circuit, *pins) }
+
+    end
+
+    def _equivalent_pins(circuit, *pins)
+
       ( nl_a, nl_b ) = _ensure_two_netlists
 
       circuit_b = nl_b.circuit_by_name(circuit)
@@ -357,9 +387,9 @@ module LVS
 
         pin_ids_b = pins.collect do |p|
           if p.is_a?(String)
-            pin = circuit_b.pin_by_name(p) || raise("Not a valid pin name in circuit '#{circuit}': #{p}")
+            pin = circuit_b.pin_by_name(p) || raise("Not a valid pin name in circuit '#{circuit}' in 'equivalent_pins': #{p}")
           else
-            pin = pins_by_index[p.to_i] || raise("Not a valid pin index in circuit '#{circuit}': #{p}")
+            pin = pins_by_index[p.to_i] || raise("Not a valid pin index in circuit '#{circuit}' in 'equivalent_pins': #{p}")
           end
           pin.id
         end