Added parser support for SV modport declarations.

Makefile.in

@@ -118,8 +118,8 @@ O = main.o async.o design_dump.o discipline.o dup_expr.o elaborate.o \
     pform_class_type.o pform_string_type.o pform_struct_type.o pform_types.o \
     symbol_search.o sync.o sys_funcs.o verinum.o verireal.o target.o \
     Attrib.o HName.o Module.o PClass.o PDelays.o PEvent.o PExpr.o PGate.o \
-    PGenerate.o PPackage.o PScope.o PSpec.o PTask.o PUdp.o PFunction.o PWire.o \
+    PGenerate.o PModport.o PPackage.o PScope.o PSpec.o PTask.o PUdp.o \
-    Statement.o AStatement.o $M $(FF) $(TT)
+    PFunction.o PWire.o Statement.o AStatement.o $M $(FF) $(TT)
 
 all: dep config.h _pli_types.h version_tag.h ivl@EXEEXT@ version.exe iverilog-vpi.man
 	$(foreach dir,$(SUBDIRS),$(MAKE) -C $(dir) $@ && ) true

Module.h

@@ -1,7 +1,7 @@
 #ifndef IVL_Module_H
 #define IVL_Module_H
 /*
- * Copyright (c) 1998-2014 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-2015 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -35,6 +35,7 @@ class PExpr;
 class PEIdent;
 class PGate;
 class PGenerate;
+class PModport;
 class PSpecPath;
 class PTask;
 class PFunction;
@@ -68,7 +69,7 @@ class Module : public PScopeExtra, public LineInfo {
 
     public:
 	/* The name passed here is the module name, not the instance
-	   name. This make must be a permallocated string. */
+	   name. This name must be a permallocated string. */
       explicit Module(LexicalScope*parent, perm_string name);
       ~Module();
 
@@ -134,6 +135,11 @@ class Module : public PScopeExtra, public LineInfo {
 	   unless they are instantiated, implicitly or explicitly. */
       std::map<perm_string,Module*> nested_modules;
 
+	/* An interface can contain one or more named modport lists.
+           The parser will ensure these don't appear in modules or
+           program blocks. */
+      map<perm_string,PModport*> modports;
+
       list<PSpecPath*> specify_paths;
 
 	// The mod_name() is the name of the module type.

PModport.cc

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2015 Stephen Williams (steve@icarus.com)
+ *
+ *    This source code is free software; you can redistribute it
+ *    and/or modify it in source code form 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 "config.h"
+
+# include  "PModport.h"
+
+PModport::PModport(perm_string n)
+: name_(n)
+{
+}
+
+PModport::~PModport()
+{
+}

PModport.h

@@ -0,0 +1,52 @@
+#ifndef IVL_PModport_H
+#define IVL_PModport_H
+/*
+ * Copyright (c) 2015 Stephen Williams (steve@icarus.com)
+ *
+ *    This source code is free software; you can redistribute it
+ *    and/or modify it in source code form 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  "LineInfo.h"
+# include  "PScope.h"
+# include  "StringHeap.h"
+# include  "netlist.h"
+# include  <vector>
+
+/*
+ * The PModport class represents a parsed SystemVerilog modport list.
+ */
+class PModport : public LineInfo {
+
+    public:
+	// The name is a perm-allocated string. It is the simple name
+	// of the modport, without any scope.
+      explicit PModport(perm_string name);
+      ~PModport();
+
+      perm_string name() const { return name_; }
+
+      typedef pair <NetNet::PortType,PExpr*> simple_port_t;
+      map<perm_string,simple_port_t> simple_ports;
+
+    private:
+      perm_string name_;
+
+    private: // not implemented
+      PModport(const PModport&);
+      PModport& operator= (const PModport&);
+};
+
+#endif /* IVL_PModport_H */

parse.y

@@ -1,7 +1,7 @@
 
 %{
 /*
- * Copyright (c) 1998-2014 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-2015 Stephen Williams (steve@icarus.com)
  * Copyright CERN 2012-2013 / Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
@@ -49,6 +49,16 @@ static struct {
       data_type_t* data_type;
 } port_declaration_context = {NetNet::NONE, NetNet::NOT_A_PORT, 0};
 
+/* Modport port declaration lists use this structure for context. */
+enum modport_port_type_t { MP_NONE, MP_SIMPLE, MP_TF, MP_CLOCKING };
+static struct {
+      modport_port_type_t type;
+      union {
+	    NetNet::PortType direction;
+	    bool is_import;
+      };
+} last_modport_port = { MP_NONE, NetNet::NOT_A_PORT};
+
 /* The task and function rules need to briefly hold the pointer to the
    task/function that is currently in progress. */
 static PTask* current_task = 0;
@@ -549,6 +559,7 @@ static void current_function_set_statement(const YYLTYPE&loc, vector<Statement*>
 %type <flag>    from_exclude block_item_decls_opt
 %type <number>  number pos_neg_number
 %type <flag>    signing unsigned_signed_opt signed_unsigned_opt
+%type <flag>    import_export
 %type <flag>    K_automatic_opt K_packed_opt K_reg_opt K_static_opt K_virtual_opt
 %type <flag>    udp_reg_opt edge_operator
 %type <drive>   drive_strength drive_strength_opt dr_strength0 dr_strength1
@@ -583,7 +594,7 @@ static void current_function_set_statement(const YYLTYPE&loc, vector<Statement*>
 %type <tf_ports> task_item task_item_list task_item_list_opt
 %type <tf_ports> tf_port_declaration tf_port_item tf_port_list tf_port_list_opt
 
-%type <named_pexpr> port_name parameter_value_byname
+%type <named_pexpr> modport_simple_port port_name parameter_value_byname
 %type <named_pexprs> port_name_list parameter_value_byname_list
 
 %type <named_pexpr> attribute
@@ -1270,6 +1281,11 @@ function_declaration /* IEEE1800-2005: A.2.6 */
 
   ;
 
+import_export /* IEEE1800-2012: A.2.9 */
+  : K_import { $$ = true; }
+  | K_export { $$ = false; }
+  ;
+
 implicit_class_handle /* IEEE1800-2005: A.8.4 */
   : K_this  { $$ = pform_create_this(); }
   | K_super { $$ = pform_create_super(); }
@@ -1546,6 +1562,115 @@ method_qualifier_opt
   |
   ;
 
+modport_declaration /* IEEE1800-2012: A.2.9 */
+  : K_modport 
+      { if (!pform_in_interface())
+	      yyerror(@1, "error: modport declarations are only allowed "
+			  "in interfaces.");
+      }
+    modport_item_list ';'
+
+modport_item_list
+  : modport_item
+  | modport_item_list ',' modport_item
+  ;
+
+modport_item
+  : IDENTIFIER
+      { pform_start_modport_item(@1, $1); }
+    '(' modport_ports_list ')'
+      { pform_end_modport_item(@1); }
+  ;
+
+  /* The modport_ports_list is a LALR(2) grammar. When the parser sees a
+     ',' it needs to look ahead to the next token to decide whether it is
+     a continuation of the preceeding modport_ports_declaration, or the
+     start of a new modport_ports_declaration. bison only supports LALR(1),
+     so we have to handcraft a mini parser for this part of the syntax.
+     last_modport_port holds the state for this mini parser.*/
+
+modport_ports_list
+  : modport_ports_declaration
+  | modport_ports_list ',' modport_ports_declaration
+  | modport_ports_list ',' modport_simple_port
+      { if (last_modport_port.type == MP_SIMPLE) {
+	      pform_add_modport_port(@3, last_modport_port.direction,
+				     $3->name, $3->parm);
+	} else {
+	      yyerror(@3, "error: modport expression not allowed here.");
+	}
+	delete $3;
+      }
+  | modport_ports_list ',' modport_tf_port
+      { if (last_modport_port.type != MP_TF)
+	      yyerror(@3, "error: task/function declaration not allowed here.");
+      }
+  | modport_ports_list ',' IDENTIFIER
+      { if (last_modport_port.type == MP_SIMPLE) {
+	      pform_add_modport_port(@3, last_modport_port.direction,
+				     lex_strings.make($3), 0);
+	} else if (last_modport_port.type != MP_TF) {
+	      yyerror(@3, "error: list of identifiers not allowed here.");
+	}
+	delete[] $3;
+      }
+  | modport_ports_list ','
+      { yyerror(@2, "error: NULL port declarations are not allowed"); }
+  ;
+
+modport_ports_declaration
+  : attribute_list_opt port_direction IDENTIFIER
+      { last_modport_port.type = MP_SIMPLE;
+	last_modport_port.direction = $2;
+	pform_add_modport_port(@3, $2, lex_strings.make($3), 0);
+	delete[] $3;
+	delete $1;
+      }
+  | attribute_list_opt port_direction modport_simple_port
+      { last_modport_port.type = MP_SIMPLE;
+	last_modport_port.direction = $2;
+	pform_add_modport_port(@3, $2, $3->name, $3->parm);
+	delete $3;
+	delete $1;
+      }
+  | attribute_list_opt import_export IDENTIFIER
+      { last_modport_port.type = MP_TF;
+	last_modport_port.is_import = $2;
+	yyerror(@3, "sorry: modport task/function ports are not yet supported.");
+	delete[] $3;
+	delete $1;
+      }
+  | attribute_list_opt import_export modport_tf_port
+      { last_modport_port.type = MP_TF;
+	last_modport_port.is_import = $2;
+	yyerror(@3, "sorry: modport task/function ports are not yet supported.");
+	delete $1;
+      }
+  | attribute_list_opt K_clocking IDENTIFIER
+      { last_modport_port.type = MP_CLOCKING;
+	last_modport_port.direction = NetNet::NOT_A_PORT;
+	yyerror(@3, "sorry: modport clocking declaration is not yet supported.");
+	delete[] $3;
+	delete $1;
+      }
+  ;
+
+modport_simple_port
+  : '.' IDENTIFIER '(' expression ')'
+      { named_pexpr_t*tmp = new named_pexpr_t;
+	tmp->name = lex_strings.make($2);
+	tmp->parm = $4;
+	delete[]$2;
+	$$ = tmp;
+      }
+  ;
+
+modport_tf_port
+  : K_task IDENTIFIER
+  | K_task IDENTIFIER '(' tf_port_list_opt ')'
+  | K_function data_type_or_implicit_or_void IDENTIFIER
+  | K_function data_type_or_implicit_or_void IDENTIFIER '(' tf_port_list_opt ')'
+  ;
 
 non_integer_type /* IEEE1800-2005: A.2.2.1 */
   : K_real { $$ = real_type_t::REAL; }
@@ -4684,6 +4809,8 @@ module_item
 	pform_endgenerate();
       }
 
+  | modport_declaration
+
   | package_import_declaration
 
   /* 1364-2001 and later allow specparam declarations outside specify blocks. */
@@ -6608,7 +6735,7 @@ udp_primitive
      presence is significant. This is a fairly common pattern so
      collect those rules here. */
 
-K_automatic_opt: K_automatic { $$ = true; } | { $$ = false;} ;
+K_automatic_opt: K_automatic { $$ = true; } | { $$ = false; } ;
 K_packed_opt   : K_packed    { $$ = true; } | { $$ = false; } ;
 K_reg_opt      : K_reg       { $$ = true; } | { $$ = false; } ;
 K_static_opt   : K_static    { $$ = true; } | { $$ = false; } ;

pform.cc

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998-2014 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-2015 Stephen Williams (steve@icarus.com)
  * Copyright CERN 2013 / Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
@@ -29,6 +29,7 @@
 # include  "PPackage.h"
 # include  "PUdp.h"
 # include  "PGenerate.h"
+# include  "PModport.h"
 # include  "PSpec.h"
 # include  "discipline.h"
 # include  <list>
@@ -265,6 +266,10 @@ static unsigned scope_generate_counter = 1;
      always within a module. */
 static PGenerate*pform_cur_generate = 0;
 
+  /* This tracks the current modport list being processed. This is
+     always within an interface. */
+static PModport*pform_cur_modport = 0;
+
 static NetNet::Type pform_default_nettype = NetNet::WIRE;
 
 /*
@@ -3356,6 +3361,46 @@ PProcess* pform_make_behavior(ivl_process_type_t type, Statement*st,
       return pp;
 }
 
+void pform_start_modport_item(const struct vlltype&loc, const char*name)
+{
+      Module*scope = pform_cur_module.front();
+      ivl_assert(loc, scope && scope->is_interface);
+      ivl_assert(loc, pform_cur_modport == 0);
+
+      perm_string use_name = lex_strings.make(name);
+      pform_cur_modport = new PModport(use_name);
+      FILE_NAME(pform_cur_modport, loc);
+      if (scope->modports.find(use_name) != scope->modports.end()) {
+	    cerr << loc << ": error: duplicate declaration for modport '"
+		 << name << "' in '" << scope->mod_name() << "'." << endl;
+	    error_count += 1;
+      }
+      scope->modports[use_name] = pform_cur_modport;
+      delete[] name;
+}
+
+void pform_end_modport_item(const struct vlltype&loc)
+{
+      ivl_assert(loc, pform_cur_modport);
+      pform_cur_modport = 0;
+}
+
+void pform_add_modport_port(const struct vlltype&loc,
+                            NetNet::PortType port_type,
+                            perm_string name, PExpr*expr)
+{
+      ivl_assert(loc, pform_cur_modport);
+
+      if (pform_cur_modport->simple_ports.find(name)
+	  != pform_cur_modport->simple_ports.end()) {
+	    cerr << loc << ": error: duplicate declaration of port '"
+		 << name << "' in modport list '"
+		 << pform_cur_modport->name() << "'." << endl;
+	    error_count += 1;
+      }
+      pform_cur_modport->simple_ports[name] = make_pair(port_type, expr);
+}
+
 
 FILE*vl_input = 0;
 extern void reset_lexor();

pform.h

@@ -1,7 +1,7 @@
 #ifndef IVL_pform_H
 #define IVL_pform_H
 /*
- * Copyright (c) 1998-2014 Stephen Williams (steve@icarus.com)
+ * Copyright (c) 1998-2015 Stephen Williams (steve@icarus.com)
  *
  *    This source code is free software; you can redistribute it
  *    and/or modify it in source code form under the terms of the GNU
@@ -219,6 +219,15 @@ extern void pform_package_import(const struct vlltype&loc,
 extern PExpr* pform_package_ident(const struct vlltype&loc,
 				  PPackage*pkg, pform_name_t*ident);
 
+/*
+ * Interface related functions.
+ */
+extern void pform_start_modport_item(const struct vlltype&loc, const char*name);
+extern void pform_end_modport_item(const struct vlltype&loc);
+extern void pform_add_modport_port(const struct vlltype&loc,
+	                           NetNet::PortType port_type,
+        	                   perm_string name, PExpr*expr);
+
 /*
  * This creates an identifier aware of names that may have been
  * imported from other packages.