[arch language] Now circuit library will automatically identify the default circuit model if needed

libopenfpga/libarchopenfpga/src/circuit_library.cpp

@@ -2,6 +2,7 @@
 #include <algorithm>
 
 #include "vtr_assert.h"
+#include "vtr_log.h"
 
 #include "openfpga_port_parser.h"
 #include "circuit_library.h"
@@ -2108,6 +2109,23 @@ void CircuitLibrary::build_timing_graphs() {
   return;
 }
 
+/* Automatically identify the default models for each type*/
+void CircuitLibrary::auto_detect_default_models() {
+  /* Go through the model fast look-up */
+  for (const auto& curr_type_models : model_lookup_) {
+    if ( (1 == curr_type_models.size())
+      && (false == model_is_default(curr_type_models[0]))) {
+      /* This is the only model in this type,
+       * it is safe to set it to be default
+       * Give a warning for users
+       */
+      set_model_is_default(curr_type_models[0], true);
+      VTR_LOG_WARN("Automatically set circuit model '%s' to be default in its type.\n",
+                   model_name(curr_type_models[0]).c_str());
+    }
+  }
+}
+
 /************************************************************************
  * Internal mutators: build timing graphs 
  ***********************************************************************/

libopenfpga/libarchopenfpga/src/circuit_library.h

@@ -461,6 +461,10 @@ class CircuitLibrary {
   public: /* Public Mutators: builders */
     void build_model_links();
     void build_timing_graphs();
+    /* Automatically identify the default models for each type,
+     * suggest to do this after circuit library is built
+     */
+    void auto_detect_default_models();
   public: /* Internal mutators: build timing graphs */
     void add_edge(const CircuitModelId& model_id,
                   const CircuitPortId& from_port, const size_t& from_pin, 

libopenfpga/libarchopenfpga/src/read_xml_openfpga_arch.cpp

@@ -52,6 +52,9 @@ openfpga::Arch read_xml_openfpga_arch(const char* arch_file_name) {
     auto xml_circuit_models = get_single_child(xml_openfpga_arch, "circuit_library", loc_data);
     openfpga_arch.circuit_lib = read_xml_circuit_library(xml_circuit_models, loc_data);
 
+    /* Automatically identify the default models for circuit library */
+    openfpga_arch.circuit_lib.auto_detect_default_models();
+
     /* Build the internal links for the circuit library */
     openfpga_arch.circuit_lib.build_model_links();