Add regression test for function calls with empty arguments

Check that function calls with empty arguments are supported. Check the
general case and special cases such as calling a function with empty
arguments as part of a module port binding or force statements in automatic
contexts.

Also check that calling a function with too many trailing empty arguments
as well as passing an empty argument for a port without a default value is
an error.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

ivtest/ivltests/func_empty_arg1.v

@@ -0,0 +1,33 @@
+// Check that it is possible to call functins with empty arguments if they have
+// default values.
+
+module test;
+
+  bit failed = 1'b0;
+
+  `define check(expr, val) \
+    if (expr !== val) begin \
+      $display("FAILED. %s, expected %d, got %d", `"expr`", val, expr); \
+      failed = 1'b1; \
+    end
+
+  function integer f(integer a = 1, integer b = 2, integer c = 3);
+    return a * 100 + b * 10 + c;
+  endfunction
+
+  initial begin
+    `check(f(4, 5, 6), 456);
+    `check(f(4, 5,  ), 453);
+    `check(f(4,  , 6), 426);
+    `check(f( , 5, 6), 156);
+    `check(f(4,  ,  ), 423);
+    `check(f( , 5,  ), 153);
+    `check(f( ,  , 6), 126);
+    `check(f( ,  ,  ), 123);
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule

ivtest/ivltests/func_empty_arg2.v

@@ -0,0 +1,29 @@
+// Check that it is possible to call functins with empty arguments if they have
+// default values. Check that this works if the function call is in a module
+// port binding expression.
+
+module M (input [31:0] x, input [31:0] y);
+
+  initial begin
+    #1
+    if (x === 623 && y == 624) begin
+      $display("PASSED");
+    end else begin
+      $display("FAILED");
+    end
+  end
+
+endmodule
+
+module test;
+
+  function [31:0] f(reg [31:0] a, reg [31:0] b = 2, reg [31:0] c = 3);
+    return a * 100 + b * 10 + c;
+  endfunction
+
+  M i_m (
+    .x(f(6, )),
+    .y(f(6, , 4))
+  );
+
+endmodule

ivtest/ivltests/func_empty_arg3.v

@@ -0,0 +1,41 @@
+// Check that it is possible to call functins with empty arguments if they have
+// default values. Check that this works if the function call is part of a force
+// statement in an automatic context.
+
+module test;
+
+  bit failed = 1'b0;
+
+  `define check(expr, val) \
+    if (expr !== val) begin \
+      $display("FAILED. %s, expected %d, got %d", `"expr`", val, expr); \
+      failed = 1'b1; \
+    end
+
+  integer x, y, z, w;
+
+  function automatic integer f(integer a = 1, integer b = 2, integer c = 3);
+    return a * 100 + b * 10 + c;
+  endfunction
+
+  task automatic t;
+    force x = f(4,  , 6);
+    force y = f(4, 5,  );
+    force z = f(4,  ,  );
+    force w = f( ,  , 6);
+  endtask
+
+  initial begin
+    t;
+
+    `check(x, 426);
+    `check(y, 453);
+    `check(z, 423);
+    `check(w, 126);
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule

ivtest/ivltests/func_empty_arg_fail1.v

@@ -0,0 +1,16 @@
+// Check that passing too many empty arguments to a function results in an error.
+
+module test;
+
+  function f(integer a = 1, integer b = 2, integer c = 3);
+    return a + 10 * b + 100 * c;
+  endfunction
+
+  initial begin
+    integer x;
+    x = f( ,  ,  ,); // This should fail. 4 empty args, even though the function
+                     // only takes 3 args
+    $display("FAILED");
+  end
+
+endmodule

ivtest/ivltests/func_empty_arg_fail2.v

@@ -0,0 +1,16 @@
+// Check that passing additional empty arguments to a function results in an error.
+
+module test;
+
+  function f(integer a = 1, integer b = 2, integer c = 3);
+    return a + 10 * b + 100 * c;
+  endfunction
+
+  initial begin
+    integer x;
+    x = f(4, 5, 6, ); // This should fail. 4 empty args, even though the function
+                      // only takes 3 args
+    $display("FAILED");
+  end
+
+endmodule

ivtest/ivltests/func_empty_arg_fail3.v

@@ -0,0 +1,16 @@
+// Check that passing empty arguments to a function without any ports is an
+// error.
+
+module test;
+
+  function f();
+    return 42;
+  endfunction
+
+  initial begin
+    integer x;
+    x = f( , ); // This should fail. The function takes no arguments. 
+    $display("FAILED");
+  end
+
+endmodule

ivtest/ivltests/func_empty_arg_fail4.v

@@ -0,0 +1,16 @@
+// Check that an error is reported when passing an empty function argument for a
+// port without a default value.
+
+module test;
+
+  function f(integer a, integer b = 2);
+    return a + 10 * b + 100 * c;
+  endfunction
+
+  initial begin
+    integer x;
+    x = f( , 3); // This should fail. No default value specified.
+    $display("FAILED");
+  end
+
+endmodule

ivtest/regress-sv.list

@@ -313,6 +313,13 @@ fork_join_any		normal,-g2009		ivltests
 fork_join_dis		normal,-g2009		ivltests
 fork_join_none		normal,-g2009		ivltests
 fr49			normal,-g2009		ivltests
+func_empty_arg1		normal,-g2005-sv	ivltests
+func_empty_arg2		normal,-g2005-sv	ivltests
+func_empty_arg3		normal,-g2005-sv	ivltests
+func_empty_arg_fail1	CE,-g2005-sv		ivltests
+func_empty_arg_fail2	CE,-g2005-sv		ivltests
+func_empty_arg_fail3	CE,-g2005-sv		ivltests
+func_empty_arg_fail4	CE,-g2005-sv		ivltests
 func_init_var1		normal,-g2009		ivltests
 func_init_var2		normal,-g2009		ivltests
 func_init_var3		normal,-g2009		ivltests

ivtest/regress-vlog95.list

@@ -82,6 +82,7 @@ automatic_task3		CE			ivltests
 br942			CE			ivltests
 br_gh531		CE			ivltests
 def_nettype		CE			ivltests
+func_empty_arg3		CE,-g2005-sv		ivltests
 func_init_var1		CE,-pallowsigned=1	ivltests
 func_init_var2		CE,-pallowsigned=1	ivltests
 func_init_var3		CE,-pallowsigned=1	ivltests