SystemVerilog: package identifier tokens

This introduces a separate token type for package identifiers, to enable
parsing with just one token lookahead.

Author: kroening

src/verilog/parser.y

@@ -537,6 +537,7 @@ int yyverilogerror(const char *error)
 /* Others */
 %token TOK_ENDOFFILE
 %token TOK_NON_TYPE_IDENTIFIER
+%token TOK_PACKAGE_IDENTIFIER
 %token TOK_TYPE_IDENTIFIER
 %token TOK_NUMBER           // number, any base
 %token TOK_TIME_LITERAL     // number followed by time unit
@@ -837,9 +838,9 @@ package_declaration:
           attribute_instance_brace TOK_PACKAGE
 		{ init($$, ID_verilog_package); }
           lifetime_opt
-          package_identifier ';'
+          any_identifier ';'
 		{
-	          push_scope(stack_expr($5).id(), "::", verilog_scopet::PACKAGE);
+	          push_scope(stack_expr($5).get(ID_base_name), "::", verilog_scopet::PACKAGE);
 	        }
           timeunits_declaration_opt
           package_item_brace
@@ -848,7 +849,7 @@ package_declaration:
 		  pop_scope();
 		  $$ = $3;
 		  addswap($$, ID_module_items, $9);
-		  stack_expr($$).set(ID_base_name, stack_expr($5).id());
+		  stack_expr($$).set(ID_base_name, stack_expr($5).get(ID_base_name));
 	        }
         ;
 
@@ -4224,9 +4225,11 @@ part_select_range:
 primary:  primary_literal
 	| hierarchical_identifier_select
 	| package_scope hierarchical_identifier_select
-		{ init($$, ID_verilog_package_scope);
-		  mto($$, $1);
-		  mto($$, $2); }
+		{ $$ = $1;
+		  mto($$, $2);
+		  // exit the package scope
+		  pop_scope();
+		}
 	| concatenation 
         | multiple_concatenation
         | function_subroutine_call
@@ -4405,9 +4408,15 @@ checker_identifier: TOK_NON_TYPE_IDENTIFIER;
 
 net_identifier: identifier;
 
-package_identifier: TOK_NON_TYPE_IDENTIFIER;
+package_identifier: TOK_PACKAGE_IDENTIFIER;
 
 package_scope: package_identifier "::"
+		{
+		  init($$, ID_verilog_package_scope);
+		  // enter that scope
+		  PARSER.scopes.enter_package_scope(stack_expr($1).id());
+		  mto($$, $1);
+		}
 	;
 
 param_identifier: TOK_NON_TYPE_IDENTIFIER;

src/verilog/scanner.l

@@ -65,10 +65,7 @@ static void preprocessor()
   { newstack(yyveriloglval); \
     irep_idt irep_id = text; \
     stack_expr(yyveriloglval).id(irep_id); \
-    auto name = PARSER.scopes.lookup(irep_id); \
-    return name == nullptr ? TOK_NON_TYPE_IDENTIFIER : \
-           name->kind == verilog_scopet::TYPEDEF ? TOK_TYPE_IDENTIFIER : \
-                             TOK_NON_TYPE_IDENTIFIER; \
+    return PARSER.scopes.identifier_token(irep_id); \
   }
 #define KEYWORD(s, x) \
   { if(PARSER.parse_tree.standard >= verilog_standardt::s) \

src/verilog/verilog_scope.cpp

@@ -10,6 +10,8 @@ Author: Daniel Kroening, [email protected]
 
 #include "verilog_y.tab.h"
 
+#include <ostream>
+
 const verilog_scopet *verilog_scopest::lookup(irep_idt base_name) const
 {
   // we start from the current scope, and walk upwards to the root
@@ -27,6 +29,13 @@ const verilog_scopet *verilog_scopest::lookup(irep_idt base_name) const
   return nullptr;
 }
 
+void verilog_scopet::print_rec(std::size_t indent, std::ostream &out) const
+{
+  out << std::string(indent, ' ') << prefix << '\n';
+  for(auto &scope_it : scope_map)
+    scope_it.second.print_rec(indent + 2, out);
+}
+
 void verilog_scopest::enter_package_scope(irep_idt base_name)
 {
   // look in the global scope
@@ -36,3 +45,33 @@ void verilog_scopest::enter_package_scope(irep_idt base_name)
   else
     enter_scope(name_it->second); // found it
 }
+
+unsigned verilog_scopest::identifier_token(irep_idt base_name) const
+{
+  auto scope = lookup(base_name);
+  if(scope == nullptr)
+  {
+    return TOK_NON_TYPE_IDENTIFIER;
+  }
+  else
+  {
+    switch(scope->kind)
+    {
+    // clang-format off
+    case verilog_scopet::GLOBAL:    return TOK_NON_TYPE_IDENTIFIER;
+    case verilog_scopet::FILE:      return TOK_NON_TYPE_IDENTIFIER;
+    case verilog_scopet::PACKAGE:   return TOK_PACKAGE_IDENTIFIER;
+    case verilog_scopet::MODULE:    return TOK_NON_TYPE_IDENTIFIER;
+    case verilog_scopet::CLASS:     return TOK_NON_TYPE_IDENTIFIER;
+    case verilog_scopet::BLOCK:     return TOK_NON_TYPE_IDENTIFIER;
+    case verilog_scopet::ENUM_NAME: return TOK_NON_TYPE_IDENTIFIER;
+    case verilog_scopet::TASK:      return TOK_NON_TYPE_IDENTIFIER;
+    case verilog_scopet::FUNCTION:  return TOK_NON_TYPE_IDENTIFIER;
+    case verilog_scopet::TYPEDEF:   return TOK_TYPE_IDENTIFIER;
+    case verilog_scopet::OTHER:     return TOK_NON_TYPE_IDENTIFIER;
+      // clang-format on
+    }
+
+    UNREACHABLE;
+  }
+}

src/verilog/verilog_scope.h

@@ -11,6 +11,7 @@ Author: Daniel Kroening, [email protected]
 
 #include <util/irep.h>
 
+#include <iosfwd>
 #include <map>
 
 // parser scopes and identifiers
@@ -62,6 +63,13 @@ struct verilog_scopet
     return __base_name;
   }
 
+  void print(std::ostream &out) const
+  {
+    print_rec(0, out);
+  }
+
+  void print_rec(std::size_t indent, std::ostream &) const;
+
   // sub-scopes
   using scope_mapt = std::map<irep_idt, verilog_scopet>;
   scope_mapt scope_map;
@@ -121,6 +129,10 @@ class verilog_scopest
   // Look up an identifier, starting from the current scope,
   // going upwards until found. Returns nullptr when not found.
   const scopet *lookup(irep_idt base_name) const;
+
+  // token to be returned by the scanner for the given identifier
+  // in the current scope
+  unsigned identifier_token(irep_idt base_name) const;
 };
 
 #endif