odb/cdl: Handle top-level pins wired to nets of different name

ATM the code seem to assume that for each top level pin, the
net name is equal to the pin name.

That's not always the case and this produces an incorect netlist.

To solve that, during pin name enumeration when creating the subckt
line, we create a mapping from "net name" -> "pin name" for each
pin connected to a net of a different name. Then when outputting
the connections between sub blocks, we use the pin name instead
of the DB net name.

Signed-off-by: Sylvain Munaut <[email protected]>

src/odb/src/cdl/cdl.cpp

@@ -89,6 +89,7 @@ std::string getUnconnectedNet(dbBlock* block, int& unconnectedNets)
 std::string getNetName(dbBlock* block,
                        dbInst* inst,
                        dbMTerm* mterm,
+                       std::map<std::string,std::string> &net2pin,
                        int& unconnectedNets)
 {
   if (mterm == nullptr) {
@@ -105,7 +106,14 @@ std::string getNetName(dbBlock* block,
     return getUnconnectedNet(block, unconnectedNets);
   }
 
-  return net->getName();
+  std::string net_name = net->getName();
+
+  auto pin_name_match = net2pin.find(net_name);
+  if (pin_name_match != net2pin.end()) {
+    return pin_name_match->second;
+  }
+
+  return net_name;
 }
 
 // Look for .subckt lines and record the terminal order for module to
@@ -189,6 +197,7 @@ bool cdl::writeCdl(utl::Logger* logger,
   }
   int unconnectedNets = 0;
   utl::FileHandler fileHandler(outFileName);
+  std::map<std::string,std::string> net2pin;
   FILE* f = fileHandler.getFile();
 
   if (f == nullptr) {
@@ -204,6 +213,10 @@ bool cdl::writeCdl(utl::Logger* logger,
   std::string line = ".SUBCKT " + block->getName();
   for (auto&& pin : block->getBTerms()) {
     line += " " + pin->getName();
+    auto net = pin->getNet();
+    if ((net != nullptr) && (net->getName() != pin->getName())) {
+      net2pin.emplace(net->getName(), pin->getName());
+    }
   }
 
   writeLine(f, line);
@@ -231,7 +244,7 @@ bool cdl::writeCdl(utl::Logger* logger,
       }
     } else {
       for (auto&& mterm : it->second) {
-        line += " " + getNetName(block, inst, mterm, unconnectedNets);
+        line += " " + getNetName(block, inst, mterm, net2pin, unconnectedNets);
       }
     }