At the risk of beating an already dead horse, since setting a breakpoint on a "use" statement is likely to continue to cause confusions like this, I've added a hack in Devel::Trepan to see if the line that a breakpoint has been set at starts with the regexp /^\s*use\s+/. If so, a warning is issued given.
The breakpoint is still set - it is just a warning. There are many ways that this heuristic can fail. For example setting a breakpoint on a line with: use English; $x = 3; may "skip" the "use" and still stop on the assignment statement. On Mon, Dec 19, 2011 at 12:20 AM, Rocky Bernstein <ro...@cpan.org> wrote: > A while back on Tue, 31 May 2011 18:20:51 -0700 Conor wrote: > > Not exactly a high priority bug, but I found that if you set a breakpoint >> on >> a line where a 'use' statement exists, the breakpoint will show as set and >> the debugger won't complain: >> $ perl -d breakpoint-bug.pl >> Loading DB routines from perl5db.pl version 1.32 >> Editor support available. >> Enter h or `h h' for help, or `man perldebug' for more help. >> main::(breakpoint-bug.pl:7): >> 7: print "hello!\n"; >> DB<1> b 9 >> DB<2> v >> 4: use strict; >> 5: use warnings; >> 6 >> 7==> print "hello!\n"; >> 8 >> 9:b use Data::Dumper; >> 10 >> 11: print "goodbye!\n"; >> 12 >> 13: exit 0; >> DB<2> >> But, if you 'c' from line 7, you skip over the breakpoint on 9 as if it >> wasn't there. It isn't a huge problem (and I really should keep all of my >> 'use' statements at the beginning of the script), but I figured it was >> worth >> a mention. >> I couldn't figure out how to actually file a bug at http://rt.perl.organd >> http://search.cpan.org/~jesse/perl-5.14.0/lib/perl5db.pl didn't have the >> usual 'View/Report Bugs' that most modules have. I'm happy to file a bug >> if >> someone could point me in the right direction. >> -Conor > > > I just looked at this. I don't think there is a bug here. > > The code has a "use" statement. A breakpoint is set on that which the > reporter doesn't feel is respected. > However, recall that "use" happens at compile time and this occurs before > the first stop you see in the debugger. > > To verify this when I issued: > $Data::Dumper::VERSION from Devel::Trepan stopped at line 7, I got a > version string, e.g. '2.124'. (in perl5db use "p $Data::Dumper::VERSION" > > Change the "use" to a "require" which then changes the semantics, and > you'll things will work as you seem to expect it to would above. > > So in sum, I don't think there is a bug. Just perhaps confusion about how > execution works -- which I admit is confusing. > > >
