Merge pull request #816 from larsclausen/task-in-expr-fail

Report errors for task and void function calls in expressions

elab_expr.cc

@@ -1642,6 +1642,9 @@ unsigned PECallFunction::test_width(Design*des, NetScope*scope,
 	    return 0;
       }
 
+      if (def->is_void())
+	    return 0;
+
       NetScope*dscope = def->scope();
       assert(dscope);
 
@@ -2706,8 +2709,7 @@ NetExpr* PECallFunction::elaborate_expr_(Design*des, NetScope*scope,
       }
 
       // If the symbol is found, but is not a _function_ scope...
-      NetFuncDef*def = search_results.scope->func_def();
-      if (def == 0) {
+      if (search_results.scope->type() != NetScope::FUNC) {
 	      // Not a user defined function. Maybe it is an access
 	      // function for a nature? If so then elaborate it that
 	      // way.
@@ -2722,6 +2724,7 @@ NetExpr* PECallFunction::elaborate_expr_(Design*des, NetScope*scope,
 	    des->errors += 1;
 	    return 0;
       }
+      NetFuncDef*def = search_results.scope->func_def();
 
       ivl_assert(*this, def);
       ivl_assert(*this, def->scope() == search_results.scope);
@@ -2860,6 +2863,14 @@ NetExpr* PECallFunction::elaborate_base_(Design*des, NetScope*scope, NetScope*ds
       if (parm_errors)
             return 0;
 
+      if (def->is_void()) {
+	    cerr << get_fileline() << ": error: void function `"
+		 << dscope->basename() << "` can not be called in an expression."
+		 << endl;
+	    des->errors++;
+	    return nullptr;
+      }
+
 	/* Look for the return value signal for the called
 	   function. This return value is a magic signal in the scope
 	   of the function, that has the name of the function. The

ivtest/ivltests/func_void_in_expr_fail.v

@@ -0,0 +1,14 @@
+// Check that an error is reported when a void function is used in an expression
+
+module test;
+
+  function void f;
+  endfunction
+
+  initial begin
+    int x;
+    x = f() + 1; // This should fail, void function can not be used in expression
+    $display("FAILED");
+  end
+
+endmodule

ivtest/ivltests/task_in_expr_fail.v

@@ -0,0 +1,14 @@
+// Check that an error is reported when a task is used in an expression
+
+module test;
+
+  task t;
+  endtask
+
+  initial begin
+    int x;
+    x = t() + 1; // This should fail, task can not be used in expression
+    $display("FAILED");
+  end
+
+endmodule

ivtest/regress-sv.list

@@ -312,6 +312,7 @@ fr49			normal,-g2009		ivltests
 func_init_var1		normal,-g2009		ivltests
 func_init_var2		normal,-g2009		ivltests
 func_init_var3		normal,-g2009		ivltests
+func_void_in_expr_fail	CE,-g2005-sv		ivltests
 function10		CO,-g2005-sv		ivltests
 function11		CE,-g2005-sv		ivltests
 function12		normal,-g2005-sv	ivltests gold=function12.gold

ivtest/regress-vlg.list

@@ -1650,6 +1650,7 @@ task3.14D		normal			ivltests
 task3.14E		normal			ivltests
 task3.14F		normal			ivltests
 task_bypath		normal			ivltests # task enabled by complete path name.
+task_in_expr_fail	CE			ivltests
 task_inpad		normal			ivltests # Validates input of task should pad w/ 0
 task_iotypes		normal			ivltests # task ports with types.
 task_iotypes2		normal			ivltests # task ports with types.