Verilog: parse covergroup declarations

This adds grammar rules for SystemVerilog covergroup declarations.

regression/verilog/covergroup/covergroup1.desc

@@ -0,0 +1,7 @@
+CORE
+covergroup1.sv
+
+^no properties$
+^EXIT=10$
+^SIGNAL=0$
+--

regression/verilog/covergroup/covergroup1.sv

@@ -0,0 +1,9 @@
+module main;
+
+  wire clk, some_signal;
+
+  covergroup cg @(posedge clk);
+    coverpoint some_signal;
+  endgroup
+
+endmodule

src/hw_cbmc_irep_ids.h

@@ -73,6 +73,7 @@ IREP_ID_ONE(wait)
 IREP_ID_ONE(verilog_assert_property)
 IREP_ID_ONE(verilog_assume_property)
 IREP_ID_ONE(verilog_cover_property)
+IREP_ID_ONE(verilog_covergroup)
 IREP_ID_ONE(verilog_smv_assert)
 IREP_ID_ONE(verilog_smv_assume)
 IREP_ID_ONE(verilog_always)

src/verilog/parser.y

@@ -882,7 +882,7 @@ class_item:
 //	| attribute_instance_brace class_method
 //	| attribute_instance_brace class_constraint
 	  attribute_instance_brace class_declaration
-//	| attribute_instance_brace covergroup_declaration
+	| attribute_instance_brace covergroup_declaration
 	| local_parameter_declaration ';'
 	| parameter_declaration ';'
 	| ';'
@@ -1018,6 +1018,7 @@ package_or_generate_item_declaration:
 	     that let constructs may be declared in a
 	     module/interface/program/checker etc. */
 	| let_declaration
+	| covergroup_declaration
 	| ';'
 		{ init($$, ID_verilog_empty_item); }
         ;
@@ -1249,6 +1250,9 @@ enum_name_declaration_list:
           	{ $$=$1; mts($$, $3); }
 	;
 
+class_scope: class_type TOK_COLONCOLON
+	;
+
 integer_type:
 	  integer_vector_type
 	| integer_atom_type
@@ -1828,6 +1832,13 @@ task_declaration:
 task_prototype: TOK_TASK task_identifier
 	;
 
+tf_port_list_paren_opt:
+	  /* Optional */
+		{ init($$); }
+	| '(' tf_port_list_opt ')'
+		{ $$ = $2; }
+	;
+
 tf_port_list_opt:
 	/* Optional */
 		{ init($$); }
@@ -2002,6 +2013,55 @@ expression_or_dist:
 	  expression
 	;
 
+// System Verilog standard 1800-2017
+// A.2.11 Covergroup declarations
+
+covergroup_declaration:
+	  TOK_COVERGROUP new_identifier tf_port_list_paren_opt coverage_event_opt ';'
+	  coverage_spec_or_option_brace TOK_ENDGROUP
+		{ init($$, ID_verilog_covergroup); }
+	;
+
+coverage_spec_or_option_brace:
+	  /* Optional */
+	| coverage_spec_or_option_brace coverage_spec_or_option
+	;
+
+coverage_spec_or_option:
+	  attribute_instance_brace coverage_spec
+	;
+
+coverage_spec:
+	  cover_point
+	;
+
+coverage_event_opt:
+	  /* Optional */
+	| coverage_event
+	;
+
+coverage_event:
+	  clocking_event
+	;
+
+block_event_expression:
+	  block_event_expression TOK_OR block_event_expression
+	| TOK_BEGIN hierarchical_btf_identifier
+	| TOK_END hierarchical_btf_identifier
+	;
+
+hierarchical_btf_identifier:
+	  hierarchical_tf_identifier
+	| hierarchical_block_identifier
+	| method_identifier
+	| hierarchical_identifier '.' method_identifier
+	| class_scope method_identifier
+	;
+
+cover_point:
+	  TOK_COVERPOINT expression ';'
+	;
+
 // System Verilog standard 1800-2017
 // A.2.12 Let declarations
 
@@ -2845,6 +2905,11 @@ procedural_timing_control:
 // System Verilog standard 1800-2017
 // A.6.11 Clocking block
 
+clocking_event:
+	  '@' identifier
+	| '@' '(' event_expression ')'
+	;
+
 cycle_delay:
           "##" number
                 { init($$, ID_verilog_cycle_delay); mto($$, $2); }
@@ -3329,6 +3394,8 @@ ps_covergroup_identifier:
 	
 memory_identifier: identifier;
 
+method_identifier: identifier;
+
 type_identifier: TOK_TYPE_IDENTIFIER
 		{
 		  init($$, ID_typedef_type);
@@ -3362,6 +3429,8 @@ function_identifier: hierarchical_identifier
 
 hierarchical_event_identifier: event_identifier;
 
+hierarchical_block_identifier: hierarchical_identifier;
+
 hierarchical_identifier:
           identifier
         | hierarchical_identifier '.' identifier

src/verilog/verilog_elaborate.cpp

@@ -760,6 +760,9 @@ void verilog_typecheckt::collect_symbols(
   else if(module_item.id() == ID_verilog_empty_item)
   {
   }
+  else if(module_item.id() == ID_verilog_covergroup)
+  {
+  }
   else
     DATA_INVARIANT(false, "unexpected module item: " + module_item.id_string());
 }

src/verilog/verilog_interfaces.cpp

@@ -287,6 +287,9 @@ void verilog_typecheckt::interface_module_item(
   else if(module_item.id() == ID_verilog_empty_item)
   {
   }
+  else if(module_item.id() == ID_verilog_covergroup)
+  {
+  }
   else
   {
     DATA_INVARIANT(false, "unexpected module item: " + module_item.id_string());

src/verilog/verilog_synthesis.cpp

@@ -2740,6 +2740,9 @@ void verilog_synthesist::synth_module_item(
   else if(module_item.id() == ID_verilog_empty_item)
   {
   }
+  else if(module_item.id() == ID_verilog_covergroup)
+  {
+  }
   else
   {
     throw errort().with_location(module_item.source_location())

src/verilog/verilog_typecheck.cpp

@@ -1575,6 +1575,9 @@ void verilog_typecheckt::convert_module_item(
   else if(module_item.id() == ID_verilog_empty_item)
   {
   }
+  else if(module_item.id() == ID_verilog_covergroup)
+  {
+  }
   else
   {
     throw errort().with_location(module_item.source_location())