Component instantiation to replicate Verilog hierarchy

tgt-vhdl/scope.cc

@@ -70,11 +70,34 @@ static int draw_module(ivl_scope_t scope, ivl_scope_t parent)
 {
    assert(ivl_scope_type(scope) == IVL_SCT_MODULE);
 
+   // Maybe we need to create this entity first?
    vhdl_entity *ent = find_entity(ivl_scope_tname(scope)); 
    if (NULL == ent)
       ent = create_entity_for(scope);
    assert(ent);
 
+   // Is this module instantiated inside another?
+   if (parent != NULL) {
+      vhdl_entity *parent_ent = find_entity(ivl_scope_tname(parent));
+      assert(parent_ent != NULL);
+      vhdl_arch *parent_arch = parent_ent->get_arch();
+      assert(parent_arch != NULL);
+      
+      // Create a forward declaration for it
+      if (!parent_arch->have_declared_component(ent->get_name())) {
+         vhdl_decl *comp_decl = vhdl_component_decl::component_decl_for(ent);
+         parent_arch->add_decl(comp_decl);
+      }
+
+      // And an instantiation statement
+      const char *inst_name = ivl_scope_basename(scope);
+      vhdl_comp_inst *inst = new vhdl_comp_inst(inst_name, ent->get_name().c_str());
+      std::ostringstream ss;
+      ss << "Scope name " << ivl_scope_name(scope);
+      inst->set_comment(ss.str());
+      parent_arch->add_stmt(inst);      
+   }
+   
    return 0;
 }
 

tgt-vhdl/vhdl_element.cc

@@ -21,6 +21,9 @@
 #include "vhdl_element.hh"
 
 #include <algorithm>
+#include <cassert>
+#include <typeinfo>
+#include <iostream>
 
 
 //////// HELPER FUNCTIONS ////////
@@ -120,31 +123,58 @@ vhdl_arch::vhdl_arch(const char *entity, const char *name)
 
 vhdl_arch::~vhdl_arch()
 {
-   conc_stmt_list_t::iterator it;
-   for (it = stmts_.begin(); it != stmts_.end(); ++it)
+   for (conc_stmt_list_t::iterator it = stmts_.begin();
+        it != stmts_.end();
+        ++it)
       delete (*it);
    stmts_.clear();
+   
+   for (decl_list_t::iterator it = decls_.begin();
+        it != decls_.end();
+        ++it)
+      delete (*it);
+   decls_.clear();
 }
 
-void vhdl_arch::add_stmt(vhdl_conc_stmt* stmt)
+void vhdl_arch::add_stmt(vhdl_conc_stmt *stmt)
 {
    stmts_.push_back(stmt);
 }
 
+void vhdl_arch::add_decl(vhdl_decl *decl)
+{
+   decls_.push_back(decl);
+}
+
 void vhdl_arch::emit(std::ofstream &of, int level) const
 {
    emit_comment(of, level);
    of << "architecture " << name_ << " of " << entity_;
    of << " is";
-   // ...declarations...
-   // newline(indent(level));
-   newline(of, level);
+   emit_children<vhdl_decl>(of, decls_, level);
    of << "begin";
    emit_children<vhdl_conc_stmt>(of, stmts_, level);
    of << "end architecture;";
    blank_line(of, level);  // Extra blank line after architectures;
 }
 
+/*
+ * True if component `name' has already been declared in this
+ * architecture. This is a bit of hack, since it uses typeid
+ * to distinguish between components and other declarations.
+ */
+bool vhdl_arch::have_declared_component(const std::string &name) const
+{
+   std::string comp_typename(typeid(vhdl_component_decl).name());
+   decl_list_t::const_iterator it;
+   for (it = decls_.begin(); it != decls_.end(); ++it) {
+      if (comp_typename == typeid(**it).name()
+          && (*it)->get_name() == name)
+         return true;
+   }
+   return false;
+}
+
 
 //////// PROCESS ////////
 
@@ -183,3 +213,51 @@ void vhdl_process::emit(std::ofstream &of, int level) const
    of << "end process;";
    newline(of, level);
 }
+
+
+//////// COMPONENT INSTANTIATION ////////
+
+vhdl_comp_inst::vhdl_comp_inst(const char *inst_name, const char *comp_name)
+   : comp_name_(comp_name), inst_name_(inst_name)
+{
+   
+}
+
+void vhdl_comp_inst::emit(std::ofstream &of, int level) const
+{
+   // If there are no ports or generics we don't need to mention them...
+   emit_comment(of, level);
+   of << inst_name_ << ": " << comp_name_ << ";";
+   newline(of, level);
+}
+
+
+//////// COMPONENT DECLARATIONS ////////
+
+vhdl_component_decl::vhdl_component_decl(const char *name)
+   : vhdl_decl(name)
+{
+
+}
+
+/*
+ * Create a component declaration for the given entity.
+ */
+vhdl_component_decl *vhdl_component_decl::component_decl_for(const vhdl_entity *ent)
+{
+   assert(ent != NULL);
+
+   vhdl_component_decl *decl = new vhdl_component_decl
+      (ent->get_name().c_str());
+
+   return decl;
+}
+
+void vhdl_component_decl::emit(std::ofstream &of, int level) const
+{
+   emit_comment(of, level);
+   of << "component " << name_ << " is";
+   // ...ports...
+   newline(of, level);
+   of << "end component;";
+}

tgt-vhdl/vhdl_element.hh

@@ -25,6 +25,8 @@
 #include <list>
 #include <string>
 
+class vhdl_entity;
+
 /*
  * Any VHDL syntax element. Each element can also contain a comment.
  */
@@ -66,6 +68,60 @@ public:
 
 typedef std::list<vhdl_seq_stmt*> seq_stmt_list_t;
 
+/*
+ * A declaration of some sort (variable, component, etc.).
+ * Declarations have names, which is the identifier of the variable,
+ * constant, etc. not the type.
+ */
+class vhdl_decl : public vhdl_element {
+public:
+   vhdl_decl(const char *name) : name_(name) {}
+   virtual ~vhdl_decl() {};
+
+   const std::string &get_name() const { return name_; }
+protected:
+   std::string name_;
+};
+
+typedef std::list<vhdl_decl*> decl_list_t;
+   
+
+/*
+ * A forward declaration of a component. At the moment it is assumed
+ * that components declarations will only ever be for entities
+ * generated by this code generator. This is enforced by making the
+ * constructor private (use component_decl_for instead).
+ */
+class vhdl_component_decl : public vhdl_decl {
+public:
+   virtual ~vhdl_component_decl() {};
+   
+   static vhdl_component_decl *component_decl_for(const vhdl_entity *ent);
+
+   void emit(std::ofstream &of, int level) const;
+private:
+   vhdl_component_decl(const char *name);
+
+   // TODO: Ports, etc.
+};
+
+
+/*
+ * Instantiation of component. This is really only a placeholder
+ * at the moment until the port mappings are worked out.
+ */
+class vhdl_comp_inst : public vhdl_conc_stmt {
+public:
+   vhdl_comp_inst(const char *inst_name, const char *comp_name);
+   virtual ~vhdl_comp_inst() {}
+
+   void emit(std::ofstream &of, int level) const;
+private:
+   std::string comp_name_, inst_name_;
+
+   // TODO: Port mappings, etc.
+};
+
 
 /*
  * Container for sequential statements.
@@ -76,7 +132,7 @@ public:
    virtual ~vhdl_process();
 
    void emit(std::ofstream &of, int level) const;
-   void add_stmt(vhdl_seq_stmt* stmt);
+   void add_stmt(vhdl_seq_stmt *stmt);
 private:
    seq_stmt_list_t stmts_;
    std::string name_;
@@ -84,8 +140,7 @@ private:
 
 
 /*
- * An architecture which implements an entity. Entities are `derived'
- * from instantiations of Verilog module scopes in the hierarchy.
+ * An architecture which implements an entity.
  */
 class vhdl_arch : public vhdl_element {
 public:
@@ -93,16 +148,20 @@ public:
    virtual ~vhdl_arch();
 
    void emit(std::ofstream &of, int level=0) const;
-   void add_stmt(vhdl_conc_stmt* stmt);
+   bool have_declared_component(const std::string &name) const;
+   void add_decl(vhdl_decl *decl);
+   void add_stmt(vhdl_conc_stmt *stmt);
 private:
    conc_stmt_list_t stmts_;
+   decl_list_t decls_;
    std::string name_, entity_;
 };
 
 /*
  * An entity defines the ports, parameters, etc. of a module. Each
  * entity is associated with a single architecture (although
- * technically this need not be the case). 
+ * technically this need not be the case).  Entities are `derived'
+ * from instantiations of Verilog module scopes in the hierarchy.
  */
 class vhdl_entity : public vhdl_element {
 public: