Registry: add basic ISO_C_BINDING types

modules/openfast-registry/src/registry.hpp

@@ -438,9 +438,11 @@ struct Registry
     std::map<std::string, std::shared_ptr<InterfaceData>, ci_less> interface_map;
     std::map<std::string, std::shared_ptr<Module>, ci_less> modules;
     std::map<std::string, std::shared_ptr<DataType>, ci_less> data_types;
+    std::map<std::string, std::shared_ptr<DataType>, ci_less> data_types_isocbinding;
     bool gen_c_code = false;
     bool no_extrap_interp = false;
     bool gen_inc_subs = false;
+    bool use_isocbinding = false;
 
     Registry()
     {
@@ -453,6 +455,10 @@ struct Registry
         auto R8Ki = std::make_shared<DataType>("R8Ki", "REAL(R8Ki)", DataType::Tag::Real, 64);
         auto DbKi = std::make_shared<DataType>("DbKi", "REAL(DbKi)", DataType::Tag::Real, 64);
         auto logical = std::make_shared<DataType>("Logical", "LOGICAL", DataType::Tag::Logical);
+        auto c_int    = std::make_shared<DataType>("c_int",   "INTEGER(c_int)",    DataType::Tag::Integer, 32);
+        auto c_float  = std::make_shared<DataType>("c_float", "REAL(c_float)",     DataType::Tag::Real, 32);
+        auto c_double = std::make_shared<DataType>("c_double","REAL(c_double)",    DataType::Tag::Real, 64);
+        auto c_char   = std::make_shared<DataType>("c_char",  "CHARACTER(c_char)", DataType::Tag::Character);
 
         // Derived types
         auto mesh = std::make_shared<DataType>(nullptr, "MeshType", "MeshType", "MeshType");
@@ -473,6 +479,10 @@ struct Registry
             {"logical", logical},
             {"meshtype", mesh},
             {"dll_type", dll},
+            {"c_int",c_int},
+            {"c_float",c_float},
+            {"c_double",c_double},
+            {"c_char",c_char},
         };
 
         this->interface_map = std::map<std::string, std::shared_ptr<InterfaceData>, ci_less>{
@@ -500,6 +510,15 @@ struct Registry
             {"PartialConstrStatePInputType",
              std::make_shared<InterfaceData>("PartialConstrStatePInputType", "dZdu", true)},
         };
+
+        // Map of ISO_C_BINDING types (for checks only)
+        this->data_types_isocbinding = std::map<std::string, std::shared_ptr<DataType>, ci_less>{
+            {"c_int",c_int},
+            {"c_float",c_float},
+            {"c_double",c_double},
+            {"c_char",c_char},
+        };
+
     }
 
     // Parsing
@@ -512,12 +531,20 @@ struct Registry
         // Pointer to type
         std::shared_ptr<DataType> data_type;
 
+        // if using ISO_C_BINDING, search these types first
+        auto it = data_types_isocbinding.find(type_name);
+        if (it != data_types_isocbinding.end())
+        {
+            this->use_isocbinding = true;
+            return it->second;
+        }
+
         // Get map of data types to search
         // If module was provided, search it; otherwise, search registry
         auto &data_types = mod == nullptr ? this->data_types : mod->data_types;
 
         // Search for type in registry, return if found
-        auto it = data_types.find(type_name);
+        it = data_types.find(type_name);
         if (it != data_types.end())
         {
             return it->second;

modules/openfast-registry/src/registry_gen_fortran.cpp

@@ -97,6 +97,10 @@ void Registry::gen_fortran_module(const Module &mod, const std::string &out_dir)
     // Write preamble
     w << std::regex_replace(FAST_preamble, std::regex("ModuleName"), mod.name);
 
+    // Output USE statements for literal passthroughs (i.e. ISO_C_BINDING)
+    if (this->use_isocbinding)
+        w << "USE ISO_C_BINDING\n";
+
     // Output USE statements for non-root modules
     for (auto const &mod : this->use_modules)
         if (tolower(mod).compare("nwtc_library") != 0)