dynvar bug

dynvar-log.txt

# without JIT
# very many of these
F $*IN_RETURN 14 10 4 11
C $*IN_RETURN 1 0 0 1
# then after inlining
I $*IN_RETURN 14 16 2 12
C $*IN_RETURN 1 0 0 1


# with JIT
F $*IN_RETURN 14 10 4 11
C $*IN_RETURN 1 0 0 1
# then a few of:
I $*IN_RETURN 14 16 2 12
C $*IN_RETURN 1 0 0 1
# and finally
F $*IN_RETURN 16 21 2 15
C $*IN_RETURN 1 1 0 1

# notably, that is two frames higher up!

failing-case.p6

use v6;
class C::C { };
# this causes a mislookup in the compiler,
# which in turn causes a miscompile, 
# which in turn causes a crash,
# which is what we notice
EVAL 'sub foo() { return C::C.new(a => 1, b => 2) }; foo()' for ^500

not-a-reproduction.nqp

# this code is inlined/notinlined and has a dynvar ref
# but for some reason it doesn't reproduce the bug
# probably because the getdynlex seems to be speshed out
my $bar  := 1;

my sub not-inlined() {
    $bar * $*FOO;
}

my sub inlined-assign-dynvar() {
    my $*FOO := 2;
    not-inlined() + not-inlined();
}

my sub toplevel-inliner() {
    my $*FOO := 0;
    my $sum  := inlined-assign-dynvar() + not-inlined();
    nqp::die("oh no") if $sum != 4;
}

my $i := 0;
while $i < 500 {
    $i := $i + 1;
    toplevel-inliner();
}