Unexpected behavior when ending macro with ``

[incandwo]

Calling vppreproc --simple on the file below

`define EMPTY

////////////////////////////////////////////////////////////
`define macro_v0(LABEL)     \
  class foo_``LABEL;         \
  endclass : foo_``LABEL

package p_v0;
  `macro_v0(bar)
endpackage

////////////////////////////////////////////////////////////
`define macro_v1(LABEL)     \
  class foo_``LABEL``;       \
  endclass : foo_``LABEL``

package p_v1;
  `macro_v1(bar)
endpackage

////////////////////////////////////////////////////////////
`define macro_v2(LABEL)     \
  class foo_``LABEL``;       \
  endclass : foo_``LABEL``

package p_v2;
  `macro_v2(bar)
  `EMPTY
endpackage

////////////////////////////////////////////////////////////
`define macro_v3(LABEL)     \
  class foo_``LABEL``;       \
  endclass : foo_``LABEL``   // one line comment

package p_v3;
  `macro_v3(bar)
endpackage

////////////////////////////////////////////////////////////
`define macro_v4(LABEL)     \
  class foo_``LABEL``;       \
  endclass : foo_``LABEL``   /* multi line comment */

package p_v4;
  `macro_v4(bar)
endpackage

yields

package p_v0;
  class foo_bar;         
  endclass : foo_bar
endpackage
package p_v1;
  class foo_bar;       
  endclass : 
foo_barendpackage
package p_v2;
  class foo_bar;       
  endclass : 
  foo_bar
endpackage
package p_v3;
  class foo_bar;       
  endclass : 
foo_barendpackage
package p_v4;
  class foo_bar;       
  endclass :    foo_bar 
endpackage

which is unexpected. I've annotated it below with my expectation

package p_v0;
  class foo_bar;         
  endclass : foo_bar
endpackage

package p_v1;
  class foo_bar;       
  endclass : <- unexpected newline before "foo_"
foo_barendpackage <- unexpected concatenation of "_bar" and "endpackage", expected newline post macro call to break both up

package p_v2;
  class foo_bar;       
  endclass : <- unexpected newline before "foo_"
  foo_bar
endpackage

package p_v3; <- same as v1
  class foo_bar;       
  endclass : 
foo_barendpackage

package p_v4;
  class foo_bar;       
  endclass :    foo_bar 
endpackage

Compiling the original code w/ Cadence Xcellium (xrun) passes and seems to work fine.

[wsnyder]

Please instead use verilator -E.

Note verilog-perl is not getting any active development so if you really need to use it, you'll need to contribute a patch to fix this. Verilator can be used as a reference.