First stab at my sub

This does just enough to get things to compile.

They currently do weird things in edge cases, including ‘Bizarre
copy of CODE’.

‘my sub’ now produces a SUB token, and goes through the same grammar
rule as ‘state sub’ and just plain ‘sub’.  The separate MYSUB branch
of the barestmt rule will go soon, as it is now unused.

4 files changed, 192 insertions, 10 deletions

diff --git a/op.c b/op.c
index bc34b3f30f..c6566e915e 100644
--- a/op.c
+++ b/op.c
@@ -6879,8 +6879,6 @@ Perl_newMYSUB(pTHX_ I32 floor, OP *o, OP *proto, OP *attrs, OP *block)
        CvOUTSIDE and find the pad belonging to the enclosing sub, where we
        store the new one. */
     name = PadlistNAMESARRAY(CvPADLIST(CvOUTSIDE(PL_compcv)))[o->op_targ];
-    if (!PadnameIsSTATE(name))
-	Perl_croak(aTHX_ "\"my sub\" not yet implemented");
     svspot =
 	&PadARRAY(PadlistARRAY(CvPADLIST(CvOUTSIDE(PL_compcv)))[1])
 	    [o->op_targ];
diff --git a/t/cmd/lexsub.t b/t/cmd/lexsub.t
index 84abff0d8f..157f5876c5 100644
--- a/t/cmd/lexsub.t
+++ b/t/cmd/lexsub.t
@@ -8,7 +8,7 @@ BEGIN {
     *bar::like = *like;
 }
 no warnings 'deprecated';
-plan 62;
+plan 104;
 
 # -------------------- our -------------------- #
 
@@ -272,3 +272,194 @@ sub make_anon_with_state_sub{
   is $w, "Subroutine redef redefined at pygpyf line 56.\n",
          "sub redefinition warnings from state subs";
 }
+
+# -------------------- my -------------------- #
+
+{
+  my sub foo { 44 }
+  isnt \&::foo, \&foo, 'my sub is not stored in the package';
+  is foo, 44, 'calling my sub from same package';
+  is &foo, 44, 'calling my sub from same package (amper)';
+  is do foo(), 44, 'calling my sub from same package (do)';
+  package bar;
+  is foo, 44, 'calling my sub from another package';
+  is &foo, 44, 'calling my sub from another package (amper)';
+  is do foo(), 44, 'calling my sub from another package (do)';
+}
+package bar;
+is foo, 43, 'my sub falling out of scope';
+is &foo, 43, 'my sub falling out of scope (called via amper)';
+is do foo(), 43, 'my sub falling out of scope (called via amper)';
+{
+  sub ma { 43 }
+  my sub ma {
+    if (shift) {
+      is ma, 43, 'my sub invisible inside itself';
+      is &ma, 43, 'my sub invisible inside itself (called via amper)';
+      is do ma(), 43, 'my sub invisible inside itself (called via do)';
+    }
+    44
+  }
+  ma(1);
+  sub mb { 43 }
+  my sub mb;
+  my sub mb {
+    if (shift) {
+      # ‘my sub foo{}’ creates a new pad entry, not reusing the forward
+      #  declaration.  Being invisible inside itself, it sees the stub.
+      eval{mb};
+      like $@, qr/^Undefined subroutine &mb called at /,
+        'my sub foo {} after forward declaration';
+      eval{&mb};
+      like $@, qr/^Undefined subroutine &mb called at /,
+        'my sub foo {} after forward declaration (amper)';
+      eval{do mb()};
+      like $@, qr/^Undefined subroutine &mb called at /,
+        'my sub foo {} after forward declaration (do)';
+    }
+    44
+  }
+  mb(1);
+  sub mb2 { 43 }
+  my sub sb2;
+  sub mb2 {
+    if (shift) {
+      package bar;
+      is mb2, 44, 'my sub visible inside itself after decl';
+      is &mb2, 44, 'my sub visible inside itself after decl (amper)';
+      is do mb2(), 44, 'my sub visible inside itself after decl (do)';
+    }
+    44
+  }
+  mb2(1);
+  my sub mb3;
+  {
+    my sub mb3 { # new pad entry
+      # The sub containing this comment is invisible inside itself.
+      # So this one here will assign to the outer pad entry:
+      sub mb3 { 47 }
+    }
+  }
+  is eval{mb3}, 47,
+    'sub foo{} applying to "my sub foo;" even inside my sub foo{}';
+}
+sub mc { 43 }
+{
+  my sub mc;
+  eval{mc};
+  like $@, qr/^Undefined subroutine &mc called at /,
+     'my sub foo; makes no lex alias for existing sub';
+  eval{&mc};
+  like $@, qr/^Undefined subroutine &mc called at /,
+     'my sub foo; makes no lex alias for existing sub (amper)';
+  eval{do mc()};
+  like $@, qr/^Undefined subroutine &mc called at /,
+     'my sub foo; makes no lex alias for existing sub (do)';
+}
+package main;
+{
+  my sub me ($);
+  is prototype eval{\&me}, '$', 'my sub with proto';
+  is prototype "me", undef, 'prototype "..." ignores my subs';
+}
+{
+  my sub if() { 44 }
+  my $x = if if if;
+  is $x, 44, 'my subs override all keywords';
+  package bar;
+  my $y = if if if;
+  is $y, 44, 'my subs from other packages override all keywords';
+}
+{
+  use warnings;
+  my $w ;
+  local $SIG{__WARN__} = sub { $w .= shift };
+  eval '#line 87 squidges
+    my sub foo;
+    my sub foo {};
+  ';
+  is $w,
+     '"my" subroutine &foo masks earlier declaration in same scope at '
+   . "squidges line 88.\n",
+     'warning for my sub masking earlier declaration';
+}
+# Test that my subs are cloned inside anonymous subs.
+sub mmake_closure {
+  my $x = shift;
+  sub {
+    my sub foo { $x }
+    foo
+  }
+}
+$sub1 = mmake_closure 48;
+$sub2 = mmake_closure 49;
+on;
+is eval { &$sub1 }, 48, 'my sub in closure (1)';
+is eval { &$sub2 }, 49, 'my sub in closure (2)';
+# Test that they are cloned in named subs.
+{
+  use warnings;
+  my $w;
+  local $SIG{__WARN__} = sub { $w .= shift };
+  eval '#line 65 teetet
+    sub foom {
+      my $x = shift;
+      my sub poom { $x }
+      eval{\&poom}
+    }
+  ';
+  is $w, undef, 'my subs get no "Variable will not stay shared" messages';
+  my $poom = foom(27);
+  my $poom2 = foom(678);
+  is eval { $poom->() }, 27, 'my subs closing over outer my var (1)';
+  is eval { $poom2->() }, 678, 'my subs closing over outer my var (2)';
+  my $x = 43;
+  my sub aoeu;
+  for $x (765) {
+    my sub etetetet { $x }
+    my sub aoeu { $x }
+    is etetetet, 765, 'my sub respects for() localisation';
+off;
+    is aoeu, 43, 'unless it is declared outside the for loop';
+  }
+}
+# And we also need to test that multiple my subs can close over each
+# other’s entries in the parent subs pad, and that cv_clone is not con-
+# fused by that.
+sub make_anon_with_my_sub{
+  sub {
+    my sub s1;
+    my sub s2 { \&s1 }
+    sub s1 { \&s2 }
+    if (@_) { return eval { \&s1 } }
+    is eval{s1},eval{\&s2}, 'my sub in anon closure closing over sibling my sub';
+    is eval{s2},eval{\&s1}, 'my sub in anon closure closing over sibling my sub';
+  }
+}
+{
+  my $s = make_anon_with_my_sub;
+  &$s;
+
+  # And make sure the my subs were actually cloned.
+on;
+  isnt make_anon_with_my_sub->(0), &$s(0),
+    'my subs in anon subs are cloned';
+  isnt &$s(0), &$s(0), 'at each invocation of the enclosing sub';
+off;
+}
+{
+  my sub BEGIN { exit };
+  pass 'my subs are never special blocks';
+  my sub END { shift }
+  is END('jkqeudth'), jkqeudth,
+    'my sub END {shift} implies @_, not @ARGV';
+}
+{
+  my sub redef {}
+  use warnings;
+  my $w;
+  local $SIG{__WARN__} = sub { $w .= shift };
+  eval "#line 56 pygpyf\nsub redef {}";
+  is $w, "Subroutine redef redefined at pygpyf line 56.\n",
+         "sub redefinition warnings from my subs";
+}
diff --git a/t/lib/croak/op b/t/lib/croak/op
index eb5974ffc4..86e40f8e95 100644
--- a/t/lib/croak/op
+++ b/t/lib/croak/op
@@ -37,11 +37,6 @@ my Foo $f = Foo->new;
 EXPECT
 No such class field "c" in variable $f of type Foo at - line 8.
 ########
-# NAME my sub
-my sub foo { }
-EXPECT
-"my sub" not yet implemented at - line 1.
-########
 # NAME delete BAD
 delete $x;
 EXPECT
diff --git a/toke.c b/toke.c
index cca84cc76e..cc123fddfa 100644
--- a/toke.c
+++ b/toke.c
@@ -8462,8 +8462,6 @@ Perl_yylex(pTHX)
 #ifndef PERL_MAD
 		force_ident_maybe_lex('&');
 #endif
-		if (key == KEY_my)
-		    TOKEN(MYSUB);
 		TOKEN(SUB);
 	    }