Author Name: Corey Teffetalor
Original Redmine Issue: 1394 from https://www.veripool.org

Original Assignee: Wilson Snyder (@wsnyder)

Due to how perl fork behaves, @verilog::Std::std@ can return no SystemVerilog std package definition. Additionally if the standards mode of Verilog::Perl is changed at runtime the std package for some Verilog versions can be blank.

In my program this happens because the @DaTa@ filehandle behaves unexpectedly after a call to fork and seems to share the filehandle seek pointer with the child process, but it's possible to reproduce without fork. The @DaTa@ filehandle in Verilog::Std is getting advanced and not reset, this results in the SystemVerilog std package not being defined for some Verilog::Perl parses.

This program should reproduce and produce the FAILED message.

use Verilog::Std;
use Verilog::Language;

my $pid = fork();

if ($pid == 0) {
	printf "Standard is %d bytes long.\n", length Verilog::Std::std();
	exit 0;
} else {
	waitpid $pid, 0;
}

my $stdLen = length Verilog::Std::std();

if ($stdLen == 0) {
	print "FAILED standard is blank!\n";
	exit 0;
} else {
	printf "PASSED standard is %d bytes long\n", $stdLen;
	exit 1;
}

However this simpler case also reproduces:

use Verilog::Std;
use Verilog::Language;

length Verilog::Std::std('1800-2009');
my $stdLen = length Verilog::Std::std();

if ($stdLen == 0) {
	print "FAILED standard is blank!\n";
	exit 0;
} else {
	printf "PASSED standard is %d bytes long\n", $stdLen;
	exit 1;
}

Instead of the @DATA@ section possibly a here-document could be used, should be good back to Perl 5.8.8 at-least?

my $stdHeader = <<'EOF';
...
import std::*;
EOF