Add regression tests for enum named constant reference order

Check that a reference before an inner enum declaration resolves to a
matching enum named constant in the outer scope, while a reference after the
declaration resolves to the inner constant.

Also check that `-gno-strict-parameter-declaration` continues to allow a
reference to a later enum named constant and identifies it correctly in the
declaration-after-use warning.

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

ivtest/gold/sv_enum_reference_order_relaxed-iverilog-stderr.gold

@@ -0,0 +1,2 @@
+ivltests/sv_enum_reference_order_relaxed.v:7: warning: enum named constant `VALUE` used before declaration.
+ivltests/sv_enum_reference_order_relaxed.v:10:        : the enum named constant is declared here.

ivtest/gold/sv_enum_reference_order_relaxed-vvp-stdout.gold

@@ -0,0 +1 @@
+PASSED

ivtest/ivltests/sv_enum_reference_order.v

@@ -0,0 +1,37 @@
+// Check that enum named constants only affect following references.
+
+typedef enum logic [1:0] {
+  VALUE = 1
+} outer_t;
+
+module test;
+
+  localparam value_before = VALUE;
+
+  typedef enum logic [1:0] {
+    VALUE = 2
+  } inner_t;
+
+  localparam value_after = VALUE;
+
+  reg failed;
+
+  `define check(val, exp) \
+    if (val !== exp) begin \
+      $display("FAILED(%0d). '%s' expected %b, got %b", `__LINE__, \
+               `"val`", exp, val); \
+      failed = 1'b1; \
+    end
+
+  initial begin
+    failed = 1'b0;
+
+    `check(value_before, 2'd1);
+    `check(value_after, 2'd2);
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule

ivtest/ivltests/sv_enum_reference_order_relaxed.v

@@ -0,0 +1,32 @@
+// Check relaxed declaration ordering for enum named constants.
+// This is not valid in strict SystemVerilog and tests
+// -gno-strict-parameter-declaration.
+
+module test;
+
+  localparam value_before = VALUE;
+
+  typedef enum logic [1:0] {
+    VALUE = 2
+  } value_t;
+
+  reg failed;
+
+  `define check(val, exp) \
+    if (val !== exp) begin \
+      $display("FAILED(%0d). '%s' expected %b, got %b", `__LINE__, \
+               `"val`", exp, val); \
+      failed = 1'b1; \
+    end
+
+  initial begin
+    failed = 1'b0;
+
+    `check(value_before, 2'd2);
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule

ivtest/regress-vvp.list

@@ -331,6 +331,8 @@ sv_declaration_after_null_statement_fail	vvp_tests/sv_declaration_after_null_sta
 sv_default_port_value1		vvp_tests/sv_default_port_value1.json
 sv_default_port_value2		vvp_tests/sv_default_port_value2.json
 sv_default_port_value3		vvp_tests/sv_default_port_value3.json
+sv_enum_reference_order	vvp_tests/sv_enum_reference_order.json
+sv_enum_reference_order_relaxed	vvp_tests/sv_enum_reference_order_relaxed.json
 sv_foreach9			vvp_tests/sv_foreach9.json
 sv_foreach10			vvp_tests/sv_foreach10.json
 sv_fork_prefix_label			vvp_tests/sv_fork_prefix_label.json

ivtest/vvp_tests/sv_enum_reference_order.json

@@ -0,0 +1,5 @@
+{
+    "type"          : "normal",
+    "source"        : "sv_enum_reference_order.v",
+    "iverilog-args" : [ "-g2005-sv" ]
+}

ivtest/vvp_tests/sv_enum_reference_order_relaxed.json

@@ -0,0 +1,6 @@
+{
+    "type"          : "normal",
+    "source"        : "sv_enum_reference_order_relaxed.v",
+    "iverilog-args" : [ "-g2005-sv", "-gno-strict-parameter-declaration" ],
+    "gold"          : "sv_enum_reference_order_relaxed"
+}