Move VHDL global state management to a single file

The new state.cc/hh file now manages all the global
state that we maintain while generating VHDL. This
should make the code a bit tidier.

tgt-vhdl/Makefile.in

@@ -49,7 +49,7 @@ dep:
 	$(CXX) $(CPPFLAGS) $(CXXFLAGS) -MD -c $< -o $*.o
 	mv $*.d dep
 
-O = vhdl.o vhdl_element.o vhdl_type.o vhdl_syntax.o scope.o process.o \
+O = vhdl.o state.o vhdl_element.o vhdl_type.o vhdl_syntax.o scope.o process.o \
 	stmt.o expr.o lpm.o display.o support.o cast.o logic.o
 
 ifeq (@WIN32@,yes)

tgt-vhdl/expr.cc

@@ -20,6 +20,7 @@
 
 #include "vhdl_target.h"
 #include "support.hh"
+#include "state.hh"
 
 #include <iostream>
 #include <cassert>

tgt-vhdl/logic.cc

@@ -20,6 +20,7 @@
 
 #include "vhdl_target.h"
 #include "vhdl_element.hh"
+#include "state.hh"
 
 #include <cassert>
 #include <sstream>
@@ -82,7 +83,6 @@ static void bufif_logic(vhdl_arch *arch, ivl_net_logic_t log, bool if0)
       cmp = new vhdl_binop_expr(sel, op, zero, NULL);
    }
    
-
    ivl_signal_t sig = find_signal_named(lhs->get_name(), arch->get_scope());
    char zbit;
    switch (ivl_signal_type(sig)) {

tgt-vhdl/lpm.cc

@@ -19,6 +19,7 @@
  */
 
 #include "vhdl_target.h"
+#include "state.hh"
 
 #include <iostream>
 #include <cassert>

tgt-vhdl/process.cc

@@ -20,6 +20,7 @@
 
 #include "vhdl_target.h"
 #include "vhdl_element.hh"
+#include "state.hh"
 
 #include <iostream>
 #include <cassert>

tgt-vhdl/scope.cc

@@ -20,70 +20,15 @@
 
 #include "vhdl_target.h"
 #include "vhdl_element.hh"
+#include "state.hh"
 
 #include <iostream>
 #include <sstream>
 #include <cassert>
 #include <cstring>
-#include <set>
-#include <algorithm>
 
 static string make_safe_name(ivl_signal_t sig);
 
-static vhdl_entity *g_active_entity = NULL;
-
-vhdl_entity *get_active_entity()
-{
-   return g_active_entity;
-}
-
-void set_active_entity(vhdl_entity *ent)
-{
-   g_active_entity = ent;
-}
-
-/*
- * Set of scopes that are treated as the default examples of
- * that type. Any other scopes of the same type are ignored.
- */
-typedef set<ivl_scope_t> default_scopes_t;
-static default_scopes_t g_default_scopes;
-
-/*
- * True if two scopes have the same type name.
- */
-static bool same_scope_type_name(ivl_scope_t a, ivl_scope_t b)
-{
-   return strcmp(ivl_scope_tname(a), ivl_scope_tname(b)) == 0;
-}
-
-/*
- * True if we have already seen a scope with this type before.
- * If the result is `false' then s is stored in the set of seen
- * scopes.
- */
-static bool seen_this_scope_type(ivl_scope_t s)
-{
-   debug_msg("Seen scope type? %s", ivl_scope_tname(s));
-   if (find_if(g_default_scopes.begin(), g_default_scopes.end(),
-               bind1st(ptr_fun(same_scope_type_name), s))
-       == g_default_scopes.end()) {
-      g_default_scopes.insert(s);
-      return false;
-   }
-   else
-      return true;
-}
-
-/*
- * True if this scope is the default example of this scope type.
- * All other instances of this scope type are ignored.
- */
-bool is_default_scope_instance(ivl_scope_t s)
-{
-   return find(g_default_scopes.begin(), g_default_scopes.end(), s)
-      != g_default_scopes.end();
-}
 
 /*
  * This represents the portion of a nexus that is visible within

tgt-vhdl/state.cc

@@ -0,0 +1,241 @@
+/*
+ *  Managing global state for the VHDL code generator.
+ *
+ *  Copyright (C) 2009  Nick Gasson (nick@nickg.me.uk)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "state.hh"
+#include "vhdl_syntax.hh"
+
+#include <algorithm>
+#include <string>
+#include <map>
+#include <set>
+#include <cstring>
+
+using namespace std;
+
+/*
+ * This file stores all the global state required during VHDL code
+ * generation. At present we store the following:
+ *
+ *  - A mapping from Verilog signals to the VHDL scope (entity, etc.)
+ *    where it is found, and the name of the corresponding VHDL signal.
+ *    This allows us to support renaming invalid Verilog signal names
+ *    to valid VHDL ones.
+ *
+ *  - The set of all VHDL entities generated.
+ *
+ *  - The currently active entity. "Active" here means that we are
+ *    currently generating code for a process inside the corresponding
+ *    scope. This is useful, for example, if a statement or expression
+ *    in a process needs to add are referencing something in the containing
+ *    architecture object.
+ */
+
+/*
+ * Maps a signal to the scope it is defined within. Also
+ * provides a mechanism for renaming signals -- i.e. when
+ * an output has the same name as register: valid in Verilog
+ * but not in VHDL, so two separate signals need to be
+ * defined. 
+ */
+struct signal_defn_t {
+   std::string renamed;     // The name of the VHDL signal
+   vhdl_scope *scope;       // The scope where it is defined
+};
+
+// All entities to emit.
+// These are stored in a list rather than a set so the first
+// entity added will correspond to the first (top) Verilog module
+// encountered and hence it will appear first in the output file.
+static entity_list_t g_entities;  
+
+typedef std::map<ivl_signal_t, signal_defn_t> signal_defn_map_t;
+static signal_defn_map_t g_known_signals;
+
+static vhdl_entity *g_active_entity = NULL;
+
+// Set of scopes that are treated as the default examples of
+// that type. Any other scopes of the same type are ignored.
+typedef set<ivl_scope_t> default_scopes_t;
+static default_scopes_t g_default_scopes;
+
+
+// True if signal `sig' has already been encountered by the code
+// generator. This means we have already assigned it to a VHDL code
+// object and possibly renamed it.
+bool seen_signal_before(ivl_signal_t sig)
+{
+   return g_known_signals.find(sig) != g_known_signals.end();
+}
+
+// Remember the association of signal to a VHDL code object (typically
+// an entity).
+void remember_signal(ivl_signal_t sig, vhdl_scope *scope)
+{
+   assert(!seen_signal_before(sig));
+
+   signal_defn_t defn = { ivl_signal_basename(sig), scope };
+   g_known_signals[sig] = defn;
+}
+
+// Change the VHDL name of a Verilog signal.
+void rename_signal(ivl_signal_t sig, const std::string &renamed)
+{
+   assert(seen_signal_before(sig));
+
+   g_known_signals[sig].renamed = renamed;
+}
+
+// Given a Verilog signal, return the VHDL code object where it should
+// be defined. Note that this can return a NULL pointer if `sig' hasn't
+// be encountered yet.
+vhdl_scope *find_scope_for_signal(ivl_signal_t sig)
+{
+   if (seen_signal_before(sig))
+      return g_known_signals[sig].scope;
+   else
+      return NULL;
+}
+
+// Get the name of the VHDL signal corresponding to Verilog signal `sig'.
+const std::string &get_renamed_signal(ivl_signal_t sig)
+{
+   assert(seen_signal_before(sig));
+
+   return g_known_signals[sig].renamed;
+}
+
+// TODO: Can we dispose of this???
+// -> This is only used in logic.cc to get the type of a signal connected
+//    to a logic device -> we should be able to get this from the nexus
+ivl_signal_t find_signal_named(const std::string &name, const vhdl_scope *scope)
+{
+   signal_defn_map_t::const_iterator it;
+   for (it = g_known_signals.begin(); it != g_known_signals.end(); ++it) {
+      if (((*it).second.scope == scope
+           || (*it).second.scope == scope->get_parent())
+          && (*it).second.renamed == name)
+         return (*it).first;
+   }
+   assert(false);
+}
+
+// Compare the name of an entity against a string
+struct cmp_ent_name {
+   cmp_ent_name(const string& n) : name_(n) {}
+   
+   bool operator()(const vhdl_entity* ent) const
+   {
+      return ent->get_name() == name_;
+   }
+
+   const string& name_;
+};
+
+// Find a VHDL entity given a Verilog module scope. The VHDL entity
+// name should be the same as the Verilog module type name.
+// Note that this will return NULL if no entity has been recorded
+// for this scope type.
+vhdl_entity* find_entity(const ivl_scope_t scope)
+{
+   assert(ivl_scope_type(scope) == IVL_SCT_MODULE);
+
+   entity_list_t::const_iterator it
+      = find_if(g_entities.begin(), g_entities.end(),
+                cmp_ent_name(ivl_scope_tname(scope)));
+
+   if (it != g_entities.end())
+      return *it;
+   else
+      return NULL;
+}
+
+// Add an entity/architecture pair to the list of entities to emit.
+void remember_entity(vhdl_entity* ent)
+{
+   g_entities.push_back(ent);
+}
+
+// Print all VHDL entities, in order, to the specified output stream.
+void emit_all_entities(std::ostream& os, int max_depth)
+{
+   for (entity_list_t::iterator it = g_entities.begin();
+        it != g_entities.end();
+        ++it) {
+      if ((max_depth == 0 || (*it)->depth < max_depth))
+         (*it)->emit(os);
+   }
+}
+
+// Release all memory for the VHDL objects. No vhdl_element pointers
+// will be valid after this call.
+void free_all_vhdl_objects()
+{
+   for (entity_list_t::iterator it = g_entities.begin();
+        it != g_entities.end();
+        ++it)
+      delete (*it);
+   g_entities.clear();
+}
+
+// Return the currently active entity
+vhdl_entity *get_active_entity()
+{
+   return g_active_entity;
+}
+
+// Change the currently active entity
+void set_active_entity(vhdl_entity *ent)
+{
+   g_active_entity = ent;
+}
+/*
+ * True if two scopes have the same type name.
+ */
+static bool same_scope_type_name(ivl_scope_t a, ivl_scope_t b)
+{
+   return strcmp(ivl_scope_tname(a), ivl_scope_tname(b)) == 0;
+}
+
+/*
+ * True if we have already seen a scope with this type before.
+ * If the result is `false' then s is stored in the set of seen
+ * scopes.
+ */
+bool seen_this_scope_type(ivl_scope_t s)
+{
+   if (find_if(g_default_scopes.begin(), g_default_scopes.end(),
+               bind1st(ptr_fun(same_scope_type_name), s))
+       == g_default_scopes.end()) {
+      g_default_scopes.insert(s);
+      return false;
+   }
+   else
+      return true;
+}
+
+/*
+ * True if this scope is the default example of this scope type.
+ * All other instances of this scope type are ignored.
+ */
+bool is_default_scope_instance(ivl_scope_t s)
+{
+   return find(g_default_scopes.begin(), g_default_scopes.end(), s)
+      != g_default_scopes.end();
+}

tgt-vhdl/state.hh

@@ -0,0 +1,54 @@
+/*
+ *  Managing global state for the VHDL code generator.
+ *
+ *  Copyright (C) 2009  Nick Gasson (nick@nickg.me.uk)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef INC_VHDL_STATE_HH
+#define INC_VHDL_STATE_HH
+
+#include "ivl_target.h"
+
+#include <iosfwd>
+#include <string>
+
+class vhdl_scope;
+class vhdl_entity;
+
+// Mapping of Verilog to VHDL signals
+bool seen_signal_before(ivl_signal_t sig);
+void remember_signal(ivl_signal_t sig, vhdl_scope *scope);
+void rename_signal(ivl_signal_t sig, const std::string &renamed);
+vhdl_scope *find_scope_for_signal(ivl_signal_t sig);
+const std::string &get_renamed_signal(ivl_signal_t sig);
+ivl_signal_t find_signal_named(const std::string &name, const vhdl_scope *scope);
+
+// Manage the set of VHDL entities
+void remember_entity(vhdl_entity *ent);
+vhdl_entity *find_entity(const ivl_scope_t scope);
+void emit_all_entities(std::ostream& os, int max_depth);
+void free_all_vhdl_objects();
+
+// Get and set the active entity
+vhdl_entity *get_active_entity();
+void set_active_entity(vhdl_entity *ent);
+
+// Manage mapping of scopes to a single VHDL entity
+bool is_default_scope_instance(ivl_scope_t s);
+bool seen_this_scope_type(ivl_scope_t s);
+
+#endif  // #ifndef INC_VHDL_STATE_HH

tgt-vhdl/stmt.cc

@@ -19,6 +19,7 @@
  */
 
 #include "vhdl_target.h"
+#include "state.hh"
 
 #include <iostream>
 #include <cstring>

tgt-vhdl/support.cc

@@ -20,6 +20,7 @@
 
 #include "vhdl_target.h"
 #include "support.hh"
+#include "state.hh"
 
 #include <cassert>
 #include <iostream>

tgt-vhdl/vhdl.cc

@@ -21,6 +21,7 @@
 #include "version.h"
 #include "vhdl_target.h"
 #include "vhdl_element.hh"
+#include "state.hh"
 
 #include <iostream>
 #include <fstream>
@@ -29,10 +30,6 @@
 #include <cassert>
 #include <cstring>
 #include <cstdlib>
-#include <list>
-#include <map>
-#include <set>
-#include <algorithm>
 
 static const char*version_string =
 "Icarus Verilog VHDL Code Generator " VERSION " (" VERSION_TAG ")\n\n"
@@ -52,24 +49,8 @@ static const char*version_string =
 "  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.\n"
 ;
 
-/*
- * Maps a signal to the scope it is defined within. Also
- * provides a mechanism for renaming signals -- i.e. when
- * an output has the same name as register: valid in Verilog
- * but not in VHDL, so two separate signals need to be
- * defined. 
- */
-struct signal_defn_t {
-   std::string renamed;     // The name of the VHDL signal
-   vhdl_scope *scope;       // The scope where it is defined
-};
-
-typedef std::map<ivl_signal_t, signal_defn_t> signal_defn_map_t;
-
 
 static int g_errors = 0;  // Total number of errors encountered
-static entity_list_t g_entities;  // All entities to emit
-static signal_defn_map_t g_known_signals;
 static ivl_design_t g_design;
 
 
@@ -107,98 +88,6 @@ void debug_msg(const char *fmt, ...)
    va_end(args);
 }
 
-// Compare the name of an entity against a string
-struct cmp_ent_name {
-   cmp_ent_name(const string& n) : name_(n) {}
-   
-   bool operator()(const vhdl_entity* ent) const
-   {
-      return ent->get_name() == name_;
-   }
-
-   const string& name_;
-};
-
-/*
- * Find a VHDL entity given a Verilog module scope. The VHDL entity
- * name should be the same the Verilog module type name.
- */
-vhdl_entity *find_entity(const ivl_scope_t scope)
-{
-   debug_msg("find_entity %s", ivl_scope_tname(scope));
-   assert(ivl_scope_type(scope) == IVL_SCT_MODULE);
-
-   entity_list_t::const_iterator it
-      = find_if(g_entities.begin(), g_entities.end(),
-                cmp_ent_name(ivl_scope_tname(scope)));
-
-   if (it != g_entities.end())
-      return *it;
-   else
-      return NULL;
-}
-
-/*
- * Add an entity/architecture pair to the list of entities to emit.
- */
-void remember_entity(vhdl_entity* ent)
-{
-   g_entities.push_back(ent);
-}
-
-bool seen_signal_before(ivl_signal_t sig)
-{
-   return g_known_signals.find(sig) != g_known_signals.end();
-}
-
-/*
- * Remember the association of signal to entity.
- */
-void remember_signal(ivl_signal_t sig, vhdl_scope *scope)
-{
-   assert(!seen_signal_before(sig));
-
-   signal_defn_t defn = { ivl_signal_basename(sig), scope };
-   g_known_signals[sig] = defn;
-}
-
-/*
- * Change the VHDL name of a Verilog signal.
- */
-void rename_signal(ivl_signal_t sig, const std::string &renamed)
-{
-   assert(seen_signal_before(sig));
-
-   g_known_signals[sig].renamed = renamed;
-}
-
-vhdl_scope *find_scope_for_signal(ivl_signal_t sig)
-{
-   if (seen_signal_before(sig))
-      return g_known_signals[sig].scope;
-   else
-      return NULL;
-}
-
-const std::string &get_renamed_signal(ivl_signal_t sig)
-{
-   assert(seen_signal_before(sig));
-
-   return g_known_signals[sig].renamed;
-}
-
-ivl_signal_t find_signal_named(const std::string &name, const vhdl_scope *scope)
-{
-   signal_defn_map_t::const_iterator it;
-   for (it = g_known_signals.begin(); it != g_known_signals.end(); ++it) {
-      if (((*it).second.scope == scope
-           || (*it).second.scope == scope->get_parent())
-          && (*it).second.renamed == name)
-         return (*it).first;
-   }
-   assert(false);
-}
-
 ivl_design_t get_vhdl_design()
 {
    return g_design;
@@ -236,28 +125,11 @@ extern "C" int target_design(ivl_design_t des)
       // (This is handy since it means we can use atoi ;-)
       int max_depth = std::atoi(ivl_design_flag(des, "depth"));
 
-      // Make sure we only emit one example of each type of entity
-      set<string> seen_entities;
-      
-      for (entity_list_t::iterator it = g_entities.begin();
-           it != g_entities.end();
-           ++it) {
-         if (seen_entities.find((*it)->get_name()) == seen_entities.end()
-             && (max_depth == 0 || (*it)->depth < max_depth)) {
-            (*it)->emit(outfile);
-            seen_entities.insert((*it)->get_name());
-         }
-      }
-      
-      outfile.close();
+      emit_all_entities(outfile, max_depth);
    }
    
    // Clean up
-   for (entity_list_t::iterator it = g_entities.begin();
-        it != g_entities.end();
-        ++it)
-      delete (*it);
-   g_entities.clear();
+   free_all_vhdl_objects();
    
    return g_errors;
 }

tgt-vhdl/vhdl_target.h

@@ -26,23 +26,9 @@ void draw_logic(vhdl_arch *arch, ivl_net_logic_t log);
 vhdl_expr *translate_expr(ivl_expr_t e);
 vhdl_expr *translate_time_expr(ivl_expr_t e);
 
-void remember_entity(vhdl_entity *ent);
-vhdl_entity *find_entity(const ivl_scope_t scope);
-
 ivl_design_t get_vhdl_design();
-vhdl_entity *get_active_entity();
-void set_active_entity(vhdl_entity *ent);
-bool is_default_scope_instance(ivl_scope_t s);
-
 vhdl_var_ref *nexus_to_var_ref(vhdl_scope *arch_scope, ivl_nexus_t nexus);
 
-bool seen_signal_before(ivl_signal_t sig);
-void remember_signal(ivl_signal_t sig, vhdl_scope *scope);
-void rename_signal(ivl_signal_t sig, const string &renamed);
-vhdl_scope *find_scope_for_signal(ivl_signal_t sig);
-const string &get_renamed_signal(ivl_signal_t sig);
-ivl_signal_t find_signal_named(const string &name, const vhdl_scope *scope);
-
 int draw_stask_display(vhdl_procedural *proc, stmt_container *container,
                        ivl_statement_t stmt, bool newline = true);
 void prune_wait_for_0(stmt_container *container);