ppTests Extend macro_LINE to catch more unusual behaviour seen in the wild.

sv-parser-pp/testcases/expected/macro_LINE.sv

@@ -1,6 +1,19 @@
-module a;
-initial begin
-    if (3 == 0) begin
-    end
-end
+// __LINE__ = `__LINE__
+
+// This block SHOULD be emitted from the preprocessor.
+
+
+// Emitted instead.
+
+
+// The following define should have no effect.
+`define __LINE__ -2
+
+// The following undef should have no effect.
+module M;
+  initial
+    if (26 == 28)      // Should be "26 == 28".
+       $display("PASS");
+    else if (28 == 28) // Should be "28 == 28".
+       $display("FAIL");
 endmodule

sv-parser-pp/testcases/macro_LINE.sv

@@ -1,6 +1,30 @@
-module a;
-initial begin
-    if (`__LINE__ == 0) begin
-    end
-end
+// __LINE__ = `__LINE__
+
+`ifdef __LINE__
+// This block SHOULD be emitted from the preprocessor.
+`elsif UNDEFINED
+// NOT emitted.
+`endif
+
+`ifndef __LINE__
+// This block should NOT be emitted from the preprocessor.
+// However, following (conditional) definition should make it through the
+// preprocessor parsing stage without error.
+`define __LINE__ -1
+`elsif UNDEFINED
+// Emitted instead.
+`endif
+
+// The following define should have no effect.
+`define __LINE__ -2
+
+// The following undef should have no effect.
+`undef __LINE__
+
+module M;
+  initial
+    if (`__LINE__ == 28)      // Should be "26 == 28".
+       $display("PASS");
+    else if (`__LINE__ == 28) // Should be "28 == 28".
+       $display("FAIL");
 endmodule