[perl.git] branch blead updated. v5.29.3-65-gd6139ec4a9

[Dave Mitchell]

In perl.git, the branch blead has been updated

<https://perl5.git.perl.org/perl.git/commitdiff/d6139ec4a9065ae249ab512398326a70dfb2fea2?hp=747c94edea492266c6c728a9dfe08ab31180e02f>

- Log -----------------------------------------------------------------
commit d6139ec4a9065ae249ab512398326a70dfb2fea2
Author: David Mitchell <da...@iabyn.com>
Date:   Wed Oct 17 15:10:10 2018 +0100

    fix 'for reverse @array' bug on AIX
    
    RT #133558
    
    Due to what appears to be a compiler bug on AIX (or perhaps it's
    undefined behaviour which happens to work on other platforms), this line
    of code in pp_iter():
    
        inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
    
    was setting inc to 4294967295 rather than to the expected -1 (inc was a
    64-bit signed long).
    
    Fix it with a couple of judicious (IV) casts (which ought to be a NOOP).

-----------------------------------------------------------------------

Summary of changes:
 pp_hot.c   |  4 ++--
 t/op/for.t | 16 +++++++++++++++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/pp_hot.c b/pp_hot.c
index 56e3cbe6e1..dc02612042 100644
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -3932,7 +3932,7 @@ PP(pp_iter)
     case CXt_LOOP_LIST: /* for (1,2,3) */
 
         assert(OPpITER_REVERSED == 2); /* so inc becomes -1 or 1 */
-        inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
+        inc = (IV)1 - (IV)(PL_op->op_private & OPpITER_REVERSED);
         ix = (cx->blk_loop.state_u.stack.ix += inc);
         if (UNLIKELY(inc > 0
                         ? ix > cx->blk_oldsp
@@ -3947,7 +3947,7 @@ PP(pp_iter)
     case CXt_LOOP_ARY: /* for (@ary) */
 
         av = cx->blk_loop.state_u.ary.ary;
-        inc = 1 - (PL_op->op_private & OPpITER_REVERSED);
+        inc = (IV)1 - (IV)(PL_op->op_private & OPpITER_REVERSED);
         ix = (cx->blk_loop.state_u.ary.ix += inc);
         if (UNLIKELY(inc > 0
                         ? ix > AvFILL(av)
diff --git a/t/op/for.t b/t/op/for.t
index a114180f0b..f34fbd8b56 100644
--- a/t/op/for.t
+++ b/t/op/for.t
@@ -5,7 +5,7 @@ BEGIN {
     require "./test.pl";
 }
 
-plan(124);
+plan(126);
 
 # A lot of tests to check that reversed for works.
 
@@ -664,3 +664,17 @@ is(fscope(), 1, 'return via loop in sub');
     }
     is($foo, "outside", "RT #123994 array outside");
 }
+
+# RT #133558 'reverse' under AIX was causing loop to terminate
+# immediately, probably due to compiler bug
+
+{
+    my @a = qw(foo);
+    my @b;
+    push @b, $_ for (reverse @a);
+    is "@b", "foo", " RT #133558 reverse array";
+
+    @b = ();
+    push @b, $_ for (reverse 'bar');
+    is "@b", "bar", " RT #133558 reverse list";
+}

-- 
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