Add regression tests for void casts

Check that it is possible to use a function with a return type as a
statement by using a void cast.

Also check that trying to void cast a void function, a task or an
expression results in an error.

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

ivtest/ivltests/sv_void_cast1.v

@@ -0,0 +1,37 @@
+// Check that void casts are supported
+
+module test;
+
+  int a;
+  real b;
+  string c;
+
+  function int f1(int x);
+    a = x;
+    return x;
+  endfunction
+
+  function real f2(real x);
+    b = x;
+    return x;
+  endfunction
+
+  function string f3(string x);
+    c = x;
+    return x;
+  endfunction
+
+
+  initial begin
+    void'(f1(10));
+    void'(f2(1.0));
+    void'(f3("10"));
+
+    if (a === 10 && b == 1.0 && c == "10") begin
+      $display("PASSED");
+    end else begin
+      $display("FAILED");
+    end
+  end
+
+endmodule

ivtest/ivltests/sv_void_cast2.v

@@ -0,0 +1,41 @@
+// Check that void casts on class methods are supported
+
+module test;
+
+  int a;
+  real b;
+  string c;
+
+  class C;
+    function int f1(int x);
+      a = x;
+      return x;
+    endfunction
+
+    function real f2(real x);
+      b = x;
+      return x;
+    endfunction
+
+    function string f3(string x);
+      c = x;
+      return x;
+    endfunction
+  endclass
+
+  C d;
+
+  initial begin
+    d = new;
+    void'(d.f1(10));
+    void'(d.f2(1.0));
+    void'(d.f3("10"));
+
+    if (a === 10 && b == 1.0 && c == "10") begin
+      $display("PASSED");
+    end else begin
+      $display("FAILED");
+    end
+  end
+
+endmodule

ivtest/ivltests/sv_void_cast3.v

@@ -0,0 +1,18 @@
+// Check that void casts on methods of built-in types is supported
+
+module test;
+
+  int q[$];
+
+  initial begin
+    q.push_back(1);
+    void'(q.pop_back());
+
+    if (q.size() === 0) begin
+      $display("PASSED");
+    end else begin
+      $display("FAILED");
+    end
+  end
+
+endmodule

ivtest/ivltests/sv_void_cast4.v

@@ -0,0 +1,11 @@
+// Check that void casts on SystemFunctions is supported
+
+module test;
+
+  initial begin
+    void'($clog2(10));
+
+    $display("PASSED");
+  end
+
+endmodule

ivtest/ivltests/sv_void_cast_fail1.v

@@ -0,0 +1,12 @@
+// Check that void casting a void function results in an error
+
+module test;
+
+  function void f(int x);
+  endfunction
+
+  initial begin
+    void'(f(10));
+  end
+
+endmodule

ivtest/ivltests/sv_void_cast_fail2.v

@@ -0,0 +1,12 @@
+// Check that void casting a task results in an error
+
+module test;
+
+  task t(int x);
+  endtask
+
+  initial begin
+    void'(t(10));
+  end
+
+endmodule

ivtest/ivltests/sv_void_cast_fail3.v

@@ -0,0 +1,9 @@
+// Check that void casting an expression results in an error
+
+module test;
+
+  initial begin
+    void'(1+2);
+  end
+
+endmodule

ivtest/regress-sv.list

@@ -803,6 +803,13 @@ sv_var_module_output1	normal,-g2005-sv	ivltests
 sv_var_module_output2	normal,-g2005-sv	ivltests
 sv_var_package		normal,-g2005-sv	ivltests
 sv_var_task		normal,-g2005-sv	ivltests
+sv_void_cast1		normal,-g2005-sv	ivltests
+sv_void_cast2		normal,-g2005-sv	ivltests
+sv_void_cast3		normal,-g2005-sv	ivltests
+sv_void_cast4		normal,-g2005-sv	ivltests
+sv_void_cast_fail1	CE,-g2005-sv		ivltests
+sv_void_cast_fail2	CE,-g2005-sv		ivltests
+sv_void_cast_fail3	CE,-g2005-sv		ivltests
 sv_wildcard_import1	normal,-g2009		ivltests
 sv_wildcard_import2	normal,-g2009		ivltests
 sv_wildcard_import3	normal,-g2009		ivltests

ivtest/regress-vlog95.list

@@ -515,6 +515,9 @@ sv_typedef_queue_base1	CE,-g2009		ivltests  # queue
 sv_typedef_queue_base2	CE,-g2009		ivltests  # queue
 sv_typedef_queue_base3	CE,-g2009		ivltests  # queue
 sv_typedef_queue_base4	CE,-g2009		ivltests  # queue
+sv_void_cast1		CE,-g2009,-pallowsigned=1	ivltests # string
+sv_void_cast2		CE,-g2009,-pallowsigned=1	ivltests # string, class
+sv_void_cast3		CE,-g2009,-pallowsigned=1	ivltests # queue
 wait_fork		CE,-g2009		ivltests  # wait fork and join_*
 wild_cmp_err		CE,-g2009		ivltests  # ==?/!=?
 wild_cmp_err2		CE,-g2009		ivltests  # ==?/!=?
@@ -977,6 +980,7 @@ sv_var_module_output1	normal,-g2005-sv,-pallowsigned=1	ivltests
 sv_var_module_output2	normal,-g2005-sv,-pallowsigned=1	ivltests
 sv_var_package		normal,-g2005-sv,-pallowsigned=1	ivltests
 sv_var_task		normal,-g2005-sv,-pallowsigned=1	ivltests
+sv_void_cast4		normal,-g2009,-pallowsigned=1		ivltests
 test_dispwided		normal,-pallowsigned=1	ivltests gold=test_dispwided.gold
 test_inc_dec		normal,-g2009,-pallowsigned=1	ivltests
 test_enumsystem		normal,-g2009,-pallowsigned=1,ivltests/enumsystem.vhd	ivltests