Add evalbytes function

This function evaluates its argument as a byte string, regardless of
the internal encoding.  It croaks if the string contains characters
outside the byte range.  Hence evalbytes(" use utf8; '\xc4\x80' ")
will return "\x{100}", even if the original string had the UTF8 flag
on, and evalbytes(" '\xc4\x80' ") will return "\xc4\x80".

This has the side effect of fixing the deparsing of CORE::break under
‘use feature’ when there is an override.

19 files changed, 379 insertions, 236 deletions

diff --git a/MANIFEST b/MANIFEST
index 058a57203f..30dfe5703d 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -5091,6 +5091,7 @@ t/op/dor.t			See if defined-or (//) works
 t/op/do.t			See if subroutines work
 t/op/each_array.t		See if array iterators work
 t/op/each.t			See if hash iterators work
+t/op/evalbytes.t		See if evalbytes operator works
 t/op/eval.t			See if eval operator works
 t/op/exec.t			See if exec, system and qx work
 t/op/exists_sub.t		See if exists(&sub) works
diff --git a/dist/B-Deparse/Deparse.pm b/dist/B-Deparse/Deparse.pm
index b8b30f3729..428466b519 100644
--- a/dist/B-Deparse/Deparse.pm
+++ b/dist/B-Deparse/Deparse.pm
@@ -33,7 +33,10 @@ use B qw(class main_root main_start main_cv svref_2object opnumber perlstring
 	     # version number bumped to 5.15.3, this can be reduced to
 	     # just test $] < 5.015003.
 	     ($] < 5.015002 || do { require B; exists(&B::OPpCONST_ARYBASE) })
-	     ? qw(OPpCONST_ARYBASE) : ());
+	     ? qw(OPpCONST_ARYBASE) : ()),
+	 ($] < 5.015005 &&
+	     ($] < 5.015004 || do { require B; exists(&B::OPpEVAL_BYTES) })
+	     ? qw(OPpEVAL_BYTES) : ());
 $VERSION = "1.09";
 use strict;
 use vars qw/$AUTOLOAD/;
@@ -44,7 +47,7 @@ BEGIN {
     # be to fake up a dummy constant that will never actually be true.
     foreach (qw(OPpSORT_INPLACE OPpSORT_DESCEND OPpITER_REVERSED OPpCONST_NOVER
 		OPpPAD_STATE RXf_SKIPWHITE CVf_LOCKED OPpREVERSE_INPLACE
-		PMf_NONDESTRUCT OPpCONST_ARYBASE)) {
+		PMf_NONDESTRUCT OPpCONST_ARYBASE OPpEVAL_BYTES)) {
 	no strict 'refs';
 	*{$_} = sub () {0} unless *{$_}{CODE};
     }
@@ -1557,6 +1560,7 @@ my %feature_keywords = (
     when    => 'switch',
     default => 'switch',
     break   => 'switch',
+    evalbytes=>'evalbytes',
 );
 
 sub keyword {
@@ -1564,11 +1568,9 @@ sub keyword {
     my $name = shift;
     return $name if $name =~ /^CORE::/; # just in case
     if (exists $feature_keywords{$name}) {
-	return
-	  $self->{'hinthash'}
-	   && $self->{'hinthash'}{"feature_$feature_keywords{$name}"}
-	    ? $name
-	    : "CORE::$name";
+	return "CORE::$name"
+	 if !$self->{'hinthash'}
+	 || !$self->{'hinthash'}{"feature_$feature_keywords{$name}"}
     }
     if (
       $name !~ /^(?:chom?p|do|exec|glob|s(?:elect|ystem))\z/
@@ -1766,7 +1768,12 @@ sub pp_alarm { unop(@_, "alarm") }
 sub pp_sleep { maybe_targmy(@_, \&unop, "sleep") }
 
 sub pp_dofile { unop(@_, "do") }
-sub pp_entereval { unop(@_, "eval") }
+sub pp_entereval {
+    unop(
+      @_,
+      $_[1]->private & OPpEVAL_BYTES ? $_[0]->keyword('evalbytes') : "eval"
+    )
+}
 
 sub pp_ghbyname { unop(@_, "gethostbyname") }
 sub pp_gnbyname { unop(@_, "getnetbyname") }
diff --git a/dist/B-Deparse/t/core.t b/dist/B-Deparse/t/core.t
index 2d5aa32919..81d9038b8a 100644
--- a/dist/B-Deparse/t/core.t
+++ b/dist/B-Deparse/t/core.t
@@ -10,6 +10,8 @@ BEGIN {
 
 use strict;
 use Test::More;
+use feature (sprintf(":%vd", $^V)); # to avoid relying on the feature
+                                    # logic to add CORE::
 
 # Many functions appear in multiple lists, so that shift() and shift(foo)
 # are both tested.
@@ -18,7 +20,8 @@ my @nary = (
  # nullary functions
      [qw( abs alarm break chr cos chop close chdir chomp chmod chown
           chroot caller continue die dump exp exit exec endgrent
-          endpwent endnetent endhostent endservent endprotoent fork glob
+          endpwent endnetent endhostent endservent
+          endprotoent evalbytes fork glob
           getppid getpwent getprotoent gethostent getnetent getservent
           getgrent getlogin getc gmtime hex int lc log lstat length
           lcfirst localtime mkdir ord oct pop quotemeta ref rand
@@ -28,7 +31,7 @@ my @nary = (
  # unary
      [qw( abs alarm bless binmode chr cos chop close chdir chomp
           chmod chown chroot closedir die do dump exp exit exec
-          each fileno getpgrp getpwnam getpwuid getpeername
+          each evalbytes fileno getpgrp getpwnam getpwuid getpeername
           getprotobyname getprotobynumber gethostbyname
           getnetbyname getsockname getgrnam getgrgid
           getc glob gmtime hex int join keys kill lc
diff --git a/dist/B-Deparse/t/deparse.t b/dist/B-Deparse/t/deparse.t
index 53b8d23202..ef66090ee5 100644
--- a/dist/B-Deparse/t/deparse.t
+++ b/dist/B-Deparse/t/deparse.t
@@ -765,6 +765,7 @@ CORE::given ($x) {
         CORE::break;
     }
 }
+CORE::evalbytes '';
 ####
 # $#- $#+ $#{%} etc.
 my @x;
diff --git a/ext/B/t/concise-xs.t b/ext/B/t/concise-xs.t
index 67b8591701..5e88b9fe63 100644
--- a/ext/B/t/concise-xs.t
+++ b/ext/B/t/concise-xs.t
@@ -169,7 +169,7 @@ my $testpkgs = {
 		     PMf_MULTILINE PMf_ONCE PMf_SINGLELINE
 		     POSTFIX SVf_FAKE SVf_IOK SVf_NOK SVf_POK SVf_ROK
 		     SVpad_OUR SVs_RMG SVs_SMG SWAP_CHILDREN OPpPAD_STATE
-		     OPpCONST_ARYBASE
+		     OPpCONST_ARYBASE OPpEVAL_BYTES
 		     /, $] > 5.009 ? ('RXf_SKIPWHITE') : ('PMf_SKIPWHITE'),
 		    'CVf_LOCKED', # This ends up as a constant, pre or post 5.10
 		    ],
diff --git a/keywords.c b/keywords.c
index b9ef465967..921d55077e 100644
--- a/keywords.c
+++ b/keywords.c
@@ -2740,7 +2740,7 @@ Perl_keyword (pTHX_ const char *name, I32 len, bool all_keywords)
           goto unknown;
       }
 
-    case 9: /* 9 tokens of length 9 */
+    case 9: /* 10 tokens of length 9 */
       switch (name[0])
       {
         case 'U':
@@ -2759,19 +2759,39 @@ Perl_keyword (pTHX_ const char *name, I32 len, bool all_keywords)
           goto unknown;
 
         case 'e':
-          if (name[1] == 'n' &&
-              name[2] == 'd' &&
-              name[3] == 'n' &&
-              name[4] == 'e' &&
-              name[5] == 't' &&
-              name[6] == 'e' &&
-              name[7] == 'n' &&
-              name[8] == 't')
-          {                                       /* endnetent        */
-            return -KEY_endnetent;
-          }
+          switch (name[1])
+          {
+            case 'n':
+              if (name[2] == 'd' &&
+                  name[3] == 'n' &&
+                  name[4] == 'e' &&
+                  name[5] == 't' &&
+                  name[6] == 'e' &&
+                  name[7] == 'n' &&
+                  name[8] == 't')
+              {                                   /* endnetent        */
+                return -KEY_endnetent;
+              }
 
-          goto unknown;
+              goto unknown;
+
+            case 'v':
+              if (name[2] == 'a' &&
+                  name[3] == 'l' &&
+                  name[4] == 'b' &&
+                  name[5] == 'y' &&
+                  name[6] == 't' &&
+                  name[7] == 'e' &&
+                  name[8] == 's')
+              {                                   /* evalbytes        */
+                return (all_keywords || FEATURE_IS_ENABLED("evalbytes") ? -KEY_evalbytes : 0);
+              }
+
+              goto unknown;
+
+            default:
+              goto unknown;
+          }
 
         case 'g':
           if (name[1] == 'e' &&
@@ -3399,5 +3419,5 @@ unknown:
 }
 
 /* Generated from:
- * 6563b55da87af894b79ef9d777217633eee6c7b5f352ff4c17317f562247f5fc regen/keywords.pl
+ * 370a83cf6eed30dfe61a9dc611013e1014e0c5f537dc4f3872576ba8b9ef7572 regen/keywords.pl
  * ex: set ro: */
diff --git a/keywords.h b/keywords.h
index 83ad0efb56..c33f6687c1 100644
--- a/keywords.h
+++ b/keywords.h
@@ -71,202 +71,203 @@
 #define KEY_eof			55
 #define KEY_eq			56
 #define KEY_eval		57
-#define KEY_exec		58
-#define KEY_exists		59
-#define KEY_exit		60
-#define KEY_exp			61
-#define KEY_fcntl		62
-#define KEY_fileno		63
-#define KEY_flock		64
-#define KEY_for			65
-#define KEY_foreach		66
-#define KEY_fork		67
-#define KEY_format		68
-#define KEY_formline		69
-#define KEY_ge			70
-#define KEY_getc		71
-#define KEY_getgrent		72
-#define KEY_getgrgid		73
-#define KEY_getgrnam		74
-#define KEY_gethostbyaddr	75
-#define KEY_gethostbyname	76
-#define KEY_gethostent		77
-#define KEY_getlogin		78
-#define KEY_getnetbyaddr	79
-#define KEY_getnetbyname	80
-#define KEY_getnetent		81
-#define KEY_getpeername		82
-#define KEY_getpgrp		83
-#define KEY_getppid		84
-#define KEY_getpriority		85
-#define KEY_getprotobyname	86
-#define KEY_getprotobynumber	87
-#define KEY_getprotoent		88
-#define KEY_getpwent		89
-#define KEY_getpwnam		90
-#define KEY_getpwuid		91
-#define KEY_getservbyname	92
-#define KEY_getservbyport	93
-#define KEY_getservent		94
-#define KEY_getsockname		95
-#define KEY_getsockopt		96
-#define KEY_given		97
-#define KEY_glob		98
-#define KEY_gmtime		99
-#define KEY_goto		100
-#define KEY_grep		101
-#define KEY_gt			102
-#define KEY_hex			103
-#define KEY_if			104
-#define KEY_index		105
-#define KEY_int			106
-#define KEY_ioctl		107
-#define KEY_join		108
-#define KEY_keys		109
-#define KEY_kill		110
-#define KEY_last		111
-#define KEY_lc			112
-#define KEY_lcfirst		113
-#define KEY_le			114
-#define KEY_length		115
-#define KEY_link		116
-#define KEY_listen		117
-#define KEY_local		118
-#define KEY_localtime		119
-#define KEY_lock		120
-#define KEY_log			121
-#define KEY_lstat		122
-#define KEY_lt			123
-#define KEY_m			124
-#define KEY_map			125
-#define KEY_mkdir		126
-#define KEY_msgctl		127
-#define KEY_msgget		128
-#define KEY_msgrcv		129
-#define KEY_msgsnd		130
-#define KEY_my			131
-#define KEY_ne			132
-#define KEY_next		133
-#define KEY_no			134
-#define KEY_not			135
-#define KEY_oct			136
-#define KEY_open		137
-#define KEY_opendir		138
-#define KEY_or			139
-#define KEY_ord			140
-#define KEY_our			141
-#define KEY_pack		142
-#define KEY_package		143
-#define KEY_pipe		144
-#define KEY_pop			145
-#define KEY_pos			146
-#define KEY_print		147
-#define KEY_printf		148
-#define KEY_prototype		149
-#define KEY_push		150
-#define KEY_q			151
-#define KEY_qq			152
-#define KEY_qr			153
-#define KEY_quotemeta		154
-#define KEY_qw			155
-#define KEY_qx			156
-#define KEY_rand		157
-#define KEY_read		158
-#define KEY_readdir		159
-#define KEY_readline		160
-#define KEY_readlink		161
-#define KEY_readpipe		162
-#define KEY_recv		163
-#define KEY_redo		164
-#define KEY_ref			165
-#define KEY_rename		166
-#define KEY_require		167
-#define KEY_reset		168
-#define KEY_return		169
-#define KEY_reverse		170
-#define KEY_rewinddir		171
-#define KEY_rindex		172
-#define KEY_rmdir		173
-#define KEY_s			174
-#define KEY_say			175
-#define KEY_scalar		176
-#define KEY_seek		177
-#define KEY_seekdir		178
-#define KEY_select		179
-#define KEY_semctl		180
-#define KEY_semget		181
-#define KEY_semop		182
-#define KEY_send		183
-#define KEY_setgrent		184
-#define KEY_sethostent		185
-#define KEY_setnetent		186
-#define KEY_setpgrp		187
-#define KEY_setpriority		188
-#define KEY_setprotoent		189
-#define KEY_setpwent		190
-#define KEY_setservent		191
-#define KEY_setsockopt		192
-#define KEY_shift		193
-#define KEY_shmctl		194
-#define KEY_shmget		195
-#define KEY_shmread		196
-#define KEY_shmwrite		197
-#define KEY_shutdown		198
-#define KEY_sin			199
-#define KEY_sleep		200
-#define KEY_socket		201
-#define KEY_socketpair		202
-#define KEY_sort		203
-#define KEY_splice		204
-#define KEY_split		205
-#define KEY_sprintf		206
-#define KEY_sqrt		207
-#define KEY_srand		208
-#define KEY_stat		209
-#define KEY_state		210
-#define KEY_study		211
-#define KEY_sub			212
-#define KEY_substr		213
-#define KEY_symlink		214
-#define KEY_syscall		215
-#define KEY_sysopen		216
-#define KEY_sysread		217
-#define KEY_sysseek		218
-#define KEY_system		219
-#define KEY_syswrite		220
-#define KEY_tell		221
-#define KEY_telldir		222
-#define KEY_tie			223
-#define KEY_tied		224
-#define KEY_time		225
-#define KEY_times		226
-#define KEY_tr			227
-#define KEY_truncate		228
-#define KEY_uc			229
-#define KEY_ucfirst		230
-#define KEY_umask		231
-#define KEY_undef		232
-#define KEY_unless		233
-#define KEY_unlink		234
-#define KEY_unpack		235
-#define KEY_unshift		236
-#define KEY_untie		237
-#define KEY_until		238
-#define KEY_use			239
-#define KEY_utime		240
-#define KEY_values		241
-#define KEY_vec			242
-#define KEY_wait		243
-#define KEY_waitpid		244
-#define KEY_wantarray		245
-#define KEY_warn		246
-#define KEY_when		247
-#define KEY_while		248
-#define KEY_write		249
-#define KEY_x			250
-#define KEY_xor			251
-#define KEY_y			252
+#define KEY_evalbytes		58
+#define KEY_exec		59
+#define KEY_exists		60
+#define KEY_exit		61
+#define KEY_exp			62
+#define KEY_fcntl		63
+#define KEY_fileno		64
+#define KEY_flock		65
+#define KEY_for			66
+#define KEY_foreach		67
+#define KEY_fork		68
+#define KEY_format		69
+#define KEY_formline		70
+#define KEY_ge			71
+#define KEY_getc		72
+#define KEY_getgrent		73
+#define KEY_getgrgid		74
+#define KEY_getgrnam		75
+#define KEY_gethostbyaddr	76
+#define KEY_gethostbyname	77
+#define KEY_gethostent		78
+#define KEY_getlogin		79
+#define KEY_getnetbyaddr	80
+#define KEY_getnetbyname	81
+#define KEY_getnetent		82
+#define KEY_getpeername		83
+#define KEY_getpgrp		84
+#define KEY_getppid		85
+#define KEY_getpriority		86
+#define KEY_getprotobyname	87
+#define KEY_getprotobynumber	88
+#define KEY_getprotoent		89
+#define KEY_getpwent		90
+#define KEY_getpwnam		91
+#define KEY_getpwuid		92
+#define KEY_getservbyname	93
+#define KEY_getservbyport	94
+#define KEY_getservent		95
+#define KEY_getsockname		96
+#define KEY_getsockopt		97
+#define KEY_given		98
+#define KEY_glob		99
+#define KEY_gmtime		100
+#define KEY_goto		101
+#define KEY_grep		102
+#define KEY_gt			103
+#define KEY_hex			104
+#define KEY_if			105
+#define KEY_index		106
+#define KEY_int			107
+#define KEY_ioctl		108
+#define KEY_join		109
+#define KEY_keys		110
+#define KEY_kill		111
+#define KEY_last		112
+#define KEY_lc			113
+#define KEY_lcfirst		114
+#define KEY_le			115
+#define KEY_length		116
+#define KEY_link		117
+#define KEY_listen		118
+#define KEY_local		119
+#define KEY_localtime		120
+#define KEY_lock		121
+#define KEY_log			122
+#define KEY_lstat		123
+#define KEY_lt			124
+#define KEY_m			125
+#define KEY_map			126
+#define KEY_mkdir		127
+#define KEY_msgctl		128
+#define KEY_msgget		129
+#define KEY_msgrcv		130
+#define KEY_msgsnd		131
+#define KEY_my			132
+#define KEY_ne			133
+#define KEY_next		134
+#define KEY_no			135
+#define KEY_not			136
+#define KEY_oct			137
+#define KEY_open		138
+#define KEY_opendir		139
+#define KEY_or			140
+#define KEY_ord			141
+#define KEY_our			142
+#define KEY_pack		143
+#define KEY_package		144
+#define KEY_pipe		145
+#define KEY_pop			146
+#define KEY_pos			147
+#define KEY_print		148
+#define KEY_printf		149
+#define KEY_prototype		150
+#define KEY_push		151
+#define KEY_q			152
+#define KEY_qq			153
+#define KEY_qr			154
+#define KEY_quotemeta		155
+#define KEY_qw			156
+#define KEY_qx			157
+#define KEY_rand		158
+#define KEY_read		159
+#define KEY_readdir		160
+#define KEY_readline		161
+#define KEY_readlink		162
+#define KEY_readpipe		163
+#define KEY_recv		164
+#define KEY_redo		165
+#define KEY_ref			166
+#define KEY_rename		167
+#define KEY_require		168
+#define KEY_reset		169
+#define KEY_return		170
+#define KEY_reverse		171
+#define KEY_rewinddir		172
+#define KEY_rindex		173
+#define KEY_rmdir		174
+#define KEY_s			175
+#define KEY_say			176
+#define KEY_scalar		177
+#define KEY_seek		178
+#define KEY_seekdir		179
+#define KEY_select		180
+#define KEY_semctl		181
+#define KEY_semget		182
+#define KEY_semop		183
+#define KEY_send		184
+#define KEY_setgrent		185
+#define KEY_sethostent		186
+#define KEY_setnetent		187
+#define KEY_setpgrp		188
+#define KEY_setpriority		189
+#define KEY_setprotoent		190
+#define KEY_setpwent		191
+#define KEY_setservent		192
+#define KEY_setsockopt		193
+#define KEY_shift		194
+#define KEY_shmctl		195
+#define KEY_shmget		196
+#define KEY_shmread		197
+#define KEY_shmwrite		198
+#define KEY_shutdown		199
+#define KEY_sin			200
+#define KEY_sleep		201
+#define KEY_socket		202
+#define KEY_socketpair		203
+#define KEY_sort		204
+#define KEY_splice		205
+#define KEY_split		206
+#define KEY_sprintf		207
+#define KEY_sqrt		208
+#define KEY_srand		209
+#define KEY_stat		210
+#define KEY_state		211
+#define KEY_study		212
+#define KEY_sub			213
+#define KEY_substr		214
+#define KEY_symlink		215
+#define KEY_syscall		216
+#define KEY_sysopen		217
+#define KEY_sysread		218
+#define KEY_sysseek		219
+#define KEY_system		220
+#define KEY_syswrite		221
+#define KEY_tell		222
+#define KEY_telldir		223
+#define KEY_tie			224
+#define KEY_tied		225
+#define KEY_time		226
+#define KEY_times		227
+#define KEY_tr			228
+#define KEY_truncate		229
+#define KEY_uc			230
+#define KEY_ucfirst		231
+#define KEY_umask		232
+#define KEY_undef		233
+#define KEY_unless		234
+#define KEY_unlink		235
+#define KEY_unpack		236
+#define KEY_unshift		237
+#define KEY_untie		238
+#define KEY_until		239
+#define KEY_use			240
+#define KEY_utime		241
+#define KEY_values		242
+#define KEY_vec			243
+#define KEY_wait		244
+#define KEY_waitpid		245
+#define KEY_wantarray		246
+#define KEY_warn		247
+#define KEY_when		248
+#define KEY_while		249
+#define KEY_write		250
+#define KEY_x			251
+#define KEY_xor			252
+#define KEY_y			253
 
 /* Generated from:
- * 6563b55da87af894b79ef9d777217633eee6c7b5f352ff4c17317f562247f5fc regen/keywords.pl
+ * 370a83cf6eed30dfe61a9dc611013e1014e0c5f537dc4f3872576ba8b9ef7572 regen/keywords.pl
  * ex: set ro: */
diff --git a/lib/feature.pm b/lib/feature.pm
index 459c03c506..dd44d7327d 100644
--- a/lib/feature.pm
+++ b/lib/feature.pm
@@ -7,6 +7,7 @@ my %feature = (
     say             => 'feature_say',
     state           => 'feature_state',
     switch          => 'feature_switch',
+    evalbytes       => 'feature_evalbytes',
     unicode_eval    => 'feature_unieval',
     unicode_strings => 'feature_unicode',
 );
@@ -24,7 +25,8 @@ my %feature_bundle = (
     "5.12" => [qw(say state switch unicode_strings)],
     "5.13" => [qw(say state switch unicode_strings)],
     "5.14" => [qw(say state switch unicode_strings)],
-    "5.15" => [qw(say state switch unicode_strings unicode_eval)],
+    "5.15" => [qw(say state switch unicode_strings unicode_eval
+                  evalbytes)],
 );
 
 # special case
diff --git a/op.c b/op.c
index d5f1dd91a0..fc6cd04d78 100644
--- a/op.c
+++ b/op.c
@@ -3598,6 +3598,11 @@ Perl_newOP(pTHX_ I32 type, I32 flags)
     dVAR;
     OP *o;
 
+    if (type == -OP_ENTEREVAL) {
+	type = OP_ENTEREVAL;
+	flags |= OPpEVAL_BYTES<<8;
+    }
+
     assert((PL_opargs[type] & OA_CLASS_MASK) == OA_BASEOP
 	|| (PL_opargs[type] & OA_CLASS_MASK) == OA_BASEOP_OR_UNOP
 	|| (PL_opargs[type] & OA_CLASS_MASK) == OA_FILESTATOP
@@ -3640,6 +3645,11 @@ Perl_newUNOP(pTHX_ I32 type, I32 flags, OP *first)
     dVAR;
     UNOP *unop;
 
+    if (type == -OP_ENTEREVAL) {
+	type = OP_ENTEREVAL;
+	flags |= OPpEVAL_BYTES<<8;
+    }
+
     assert((PL_opargs[type] & OA_CLASS_MASK) == OA_UNOP
 	|| (PL_opargs[type] & OA_CLASS_MASK) == OA_BASEOP_OR_UNOP
 	|| (PL_opargs[type] & OA_CLASS_MASK) == OA_FILESTATOP
@@ -7469,22 +7479,26 @@ Perl_ck_eval(pTHX_ OP *o)
 	}
     }
     else {
+	U8 priv = o->op_private;
 #ifdef PERL_MAD
 	OP* const oldo = o;
 #else
 	op_free(o);
 #endif
-	o = newUNOP(OP_ENTEREVAL, 0, newDEFSVOP());
+	o = newUNOP(OP_ENTEREVAL, priv <<8, newDEFSVOP());
 	op_getmad(oldo,o,'O');
     }
     o->op_targ = (PADOFFSET)PL_hints;
-    if ((PL_hints & HINT_LOCALIZE_HH) != 0 && GvHV(PL_hintgv)) {
+    if ((PL_hints & HINT_LOCALIZE_HH) != 0
+     && !(o->op_private & OPpEVAL_COPHH) && GvHV(PL_hintgv)) {
 	/* Store a copy of %^H that pp_entereval can pick up. */
 	OP *hhop = newSVOP(OP_HINTSEVAL, 0,
 			   MUTABLE_SV(hv_copy_hints_hv(GvHV(PL_hintgv))));
 	cUNOPo->op_first->op_sibling = hhop;
 	o->op_private |= OPpEVAL_HAS_HH;
-	if (FEATURE_IS_ENABLED("unieval"))
+
+	if (!(o->op_private & OPpEVAL_BYTES)
+	 && FEATURE_IS_ENABLED("unieval"))
 	    o->op_private |= OPpEVAL_UNICODE;
     }
     return o;
@@ -9356,7 +9370,7 @@ Perl_ck_entersub_args_core(pTHX_ OP *entersubop, GV *namegv, SV *protosv)
     }
     else {
 	OP *prev, *cvop;
-	U32 paren;
+	U32 flags;
 #ifdef PERL_MAD
 	bool seenarg = FALSE;
 #endif
@@ -9375,16 +9389,20 @@ Perl_ck_entersub_args_core(pTHX_ OP *entersubop, GV *namegv, SV *protosv)
 #endif
 	    ;
 	prev->op_sibling = NULL;
-	paren = OPf_SPECIAL * !(cvop->op_private & OPpENTERSUB_NOPAREN);
+	flags = OPf_SPECIAL * !(cvop->op_private & OPpENTERSUB_NOPAREN);
 	op_free(cvop);
 	if (aop == cvop) aop = NULL;
 	op_free(entersubop);
 
+	if (opnum == OP_ENTEREVAL
+	 && GvNAMELEN(namegv)==9 && strnEQ(GvNAME(namegv), "evalbytes", 9))
+	    flags |= OPpEVAL_BYTES <<8;
+	
 	switch (PL_opargs[opnum] & OA_CLASS_MASK) {
 	case OA_UNOP:
 	case OA_BASEOP_OR_UNOP:
 	case OA_FILESTATOP:
-	    return aop ? newUNOP(opnum,paren,aop) : newOP(opnum,paren);
+	    return aop ? newUNOP(opnum,flags,aop) : newOP(opnum,flags);
 	case OA_BASEOP:
 	    if (aop) {
 #ifdef PERL_MAD
@@ -10338,6 +10356,8 @@ Perl_core_prototype(pTHX_ SV *sv, const char *name, const int code,
 	retsetpvs("+;$$@", OP_SPLICE);
     case KEY___FILE__: case KEY___LINE__: case KEY___PACKAGE__:
 	retsetpvs("", 0);
+    case KEY_evalbytes:
+	name = "entereval"; break;
     case KEY_readpipe:
 	name = "backtick";
     }
@@ -10435,7 +10455,11 @@ Perl_coresub_op(pTHX_ SV * const coreargssv, const int code,
 	                      opnum == OP_WANTARRAY ? OPpOFFBYONE << 8 : 0)
 	           );
 	case OA_BASEOP_OR_UNOP:
-	    o = newUNOP(opnum,0,argop);
+	    if (opnum == OP_ENTEREVAL) {
+		o = newUNOP(OP_ENTEREVAL,OPpEVAL_COPHH<<8,argop);
+		if (code == -KEY_evalbytes) o->op_private |= OPpEVAL_BYTES;
+	    }
+	    else o = newUNOP(opnum,0,argop);
 	    if (opnum == OP_CALLER) o->op_private |= OPpOFFBYONE;
 	    else {
 	  onearg:
diff --git a/op.h b/op.h
index a9ecedb8e4..f82758e46e 100644
--- a/op.h
+++ b/op.h
@@ -296,6 +296,8 @@ Deprecated.  Use C<GIMME_V> instead.
 /* Private for OP_ENTEREVAL */
 #define OPpEVAL_HAS_HH		2	/* Does it have a copy of %^H */
 #define OPpEVAL_UNICODE		4
+#define OPpEVAL_BYTES		8
+#define OPpEVAL_COPHH		16	/* Construct %^H from cop hints */
     
 /* Private for OP_CALLER and OP_WANTARRAY */
 #define OPpOFFBYONE		128	/* Treat caller(1) as caller(2) */
diff --git a/opcode.h b/opcode.h
index 34f8b48752..99b25240aa 100644
--- a/opcode.h
+++ b/opcode.h
@@ -2023,7 +2023,7 @@ EXTCONST U32 PL_opargs[] = {
 	0x00009bc0,	/* require */
 	0x00001140,	/* dofile */
 	0x00000604,	/* hintseval */
-	0x00001b40,	/* entereval */
+	0x00009bc0,	/* entereval */
 	0x00001100,	/* leaveeval */
 	0x00000340,	/* entertry */
 	0x00000400,	/* leavetry */
diff --git a/pp_ctl.c b/pp_ctl.c
index 153d98e604..9b9bff9a8f 100644
--- a/pp_ctl.c
+++ b/pp_ctl.c
@@ -4131,6 +4131,11 @@ PP(pp_entereval)
     if (PL_op->op_private & OPpEVAL_HAS_HH) {
 	saved_hh = MUTABLE_HV(SvREFCNT_inc(POPs));
     }
+    else if (PL_op->op_private & OPpEVAL_COPHH
+	  && PL_curcop->cop_hints & HINT_LOCALIZE_HH) {
+	saved_hh = cop_hints_2hv(PL_curcop, 0);
+	hv_magic(saved_hh, NULL, PERL_MAGIC_hints);
+    }
     sv = POPs;
     if (!SvPOK(sv)) {
 	/* make sure we've got a plain PV (no overload etc) before testing
@@ -4140,6 +4145,15 @@ PP(pp_entereval)
 	const char * const p = SvPV_const(sv, len);
 
 	sv = newSVpvn_flags(p, len, SVs_TEMP | SvUTF8(sv));
+
+	if (PL_op->op_private & OPpEVAL_BYTES && SvUTF8(sv))
+	    SvPVbyte_force(sv, len);
+    }
+    else if (PL_op->op_private & OPpEVAL_BYTES && SvUTF8(sv)) {
+	/* Don’t modify someone else’s scalar */
+	STRLEN len;
+	sv = newSVsv(sv);
+	SvPVbyte_force(sv,len);
     }
 
     TAINT_IF(SvTAINTED(sv));
@@ -4173,7 +4187,8 @@ PP(pp_entereval)
        ensues, we always turn GvMULTI_on for any globals that were
        introduced within evals. See force_ident(). GSAR 96-10-12 */
     SAVEHINTS();
-    PL_hints = PL_op->op_targ;
+    PL_hints = PL_op->op_private & OPpEVAL_COPHH
+		 ? PL_curcop->cop_hints : PL_op->op_targ;
     if (saved_hh) {
 	/* SAVEHINTS created a new HV in PL_hintgv, which we need to GC */
 	SvREFCNT_dec(GvHV(PL_hintgv));
diff --git a/regen/keywords.pl b/regen/keywords.pl
index 5f7f1ef851..c4cd187273 100755
--- a/regen/keywords.pl
+++ b/regen/keywords.pl
@@ -45,6 +45,8 @@ my %feature_kw = (
 	say     => 'say',
 
 	state	=> 'state',
+
+	evalbytes=>'evalbytes',
 	);
 
 my %pos = map { ($_ => 1) } @{$by_strength{'+'}};
@@ -165,6 +167,7 @@ __END__
 -eof
 -eq
 +eval
+-evalbytes
 -exec
 +exists
 -exit
diff --git a/regen/opcodes b/regen/opcodes
index 5b988a11aa..45cf693673 100644
--- a/regen/opcodes
+++ b/regen/opcodes
@@ -483,7 +483,7 @@ semctl		semctl			ck_fun		imst@	S S S S
 require		require			ck_require	du%	S?
 dofile		do "file"		ck_fun		d1	S
 hintseval	eval hints		ck_svconst	s$
-entereval	eval "string"		ck_eval		d%	S
+entereval	eval "string"		ck_eval		du%	S?
 leaveeval	eval "string" exit	ck_null		1	S
 #evalonce	eval constant string	ck_null		d1	S
 entertry	eval {block}		ck_eval		d|	
diff --git a/t/op/coreamp.t b/t/op/coreamp.t
index 2027f41ac5..d3f03eb58a 100644
--- a/t/op/coreamp.t
+++ b/t/op/coreamp.t
@@ -30,6 +30,7 @@ package sov {
 }
 
 my %op_desc = (
+ evalbytes=> 'eval "string"',
  join     => 'join or string',
  readline => '<HANDLE>',
  readpipe => 'quoted execution (``, qx)',
@@ -118,10 +119,11 @@ sub test_proto {
   elsif ($p =~ '^([$*]+);?\z') { # Fixed-length $$$ or ***
     my $args = length $1;
     $tests += 2;    
+    my $desc = quotemeta op_desc($o);
     eval " &CORE::$o((1)x($args-1)) ";
-    like $@, qr/^Not enough arguments for $o at /, "&$o with too few args";
+    like $@, qr/^Not enough arguments for $desc at /, "&$o w/too few args";
     eval " &CORE::$o((1)x($args+1)) ";
-    like $@, qr/^Too many arguments for $o at /, "&$o with too many args";
+    like $@, qr/^Too many arguments for $desc at /, "&$o w/too many args";
   }
   elsif ($p =~ '^([$*]+);([$*]+)\z') { # Variable-length $$$ or ***
     my $minargs = length $1;
@@ -396,6 +398,29 @@ test_proto $_ for qw(
  endgrent endhostent endnetent endprotoent endpwent endservent
 );
 
+test_proto 'evalbytes';
+$tests += 4;
+{
+  chop(my $upgraded = "use utf8; '\xc4\x80'" . chr 256);
+  is &myevalbytes($upgraded), chr 256, '&evalbytes';
+  # Test hints
+  require strict;
+  strict->import;
+  &myevalbytes('
+    is someone, "someone", "run-time hint bits do not leak into &evalbytes"
+  ');
+  use strict;
+  BEGIN { $^H{coreamp} = 42 }
+  $^H{coreamp} = 75;
+  &myevalbytes('
+    BEGIN {
+      is $^H{coreamp}, 42, "compile-time hh propagates into &evalbytes";
+    }
+    ${"frobnicate"}
+  ');
+  like $@, qr/strict/, 'compile-time hint bits propagate into &evalbytes';
+}
+
 test_proto 'exit';
 $tests ++;
 is runperl(prog => '&CORE::exit; END { print qq-ok\n- }'), "ok\n",
diff --git a/t/op/coresubs.t b/t/op/coresubs.t
index 60aa1b7814..1665cf6ab6 100644
--- a/t/op/coresubs.t
+++ b/t/op/coresubs.t
@@ -84,7 +84,7 @@ while(<$kh>) {
       # These ops currently accept any number of args, despite their
       # prototypes, if they have any:
       next if $word =~ /^(?:chom?p|exec|keys|each|not|read(?:lin|pip)e
-                           |reset|system|values|l?stat)/x;
+                           |reset|system|values|l?stat)|evalbytes/x;
 
       $tests ++;
       $code =
diff --git a/t/op/cproto.t b/t/op/cproto.t
index c9cfe466ca..ad2249df2c 100644
--- a/t/op/cproto.t
+++ b/t/op/cproto.t
@@ -7,7 +7,7 @@ BEGIN {
 }
 
 BEGIN { require './test.pl'; }
-plan tests => 245;
+plan tests => 246;
 
 while (<DATA>) {
     chomp;
@@ -77,6 +77,7 @@ endservent ()
 eof (;*)
 eq undef
 eval undef
+evalbytes (_)
 exec undef
 exists undef
 exit (;$)
diff --git a/t/op/evalbytes.t b/t/op/evalbytes.t
new file mode 100644
index 0000000000..4a60614814
--- /dev/null
+++ b/t/op/evalbytes.t
@@ -0,0 +1,34 @@
+#!./perl
+
+BEGIN {
+    chdir 't';
+    @INC = '../lib';
+    require './test.pl';
+}
+
+plan(tests => 8);
+
+{
+    local $SIG{__WARN__} = sub {};
+    eval "evalbytes 'foo'";
+    like $@, qr/syntax error/, 'evalbytes outside feature scope';
+}
+
+# We enable unicode_eval just to test that it does not interfere.
+use feature 'evalbytes', 'unicode_eval';
+
+is evalbytes("1+7"), 8, 'evalbytes basic sanity check';
+
+my $code = 'qq(\xff\xfe)';
+is evalbytes($code), "\xff\xfe", 'evalbytes on extra-ASCII bytes';
+chop((my $upcode = $code) .= chr 256);
+is evalbytes($upcode), "\xff\xfe", 'evalbytes on upgraded extra-ASCII';
+{
+    use utf8;
+    is evalbytes($code), "\xff\xfe", 'evalbytes ignores outer utf8 pragma';
+}
+is evalbytes "use utf8; '\xc4\x80'", chr 256, 'use utf8 within evalbytes';
+chop($upcode = "use utf8; '\xc4\x80'" . chr 256);
+is evalbytes $upcode, chr 256, 'use utf8 within evalbytes on utf8 string';
+eval { evalbytes chr 256 };
+like $@, qr/Wide character/, 'evalbytes croaks on non-bytes';
diff --git a/toke.c b/toke.c
index 3720a83101..b1acdd3408 100644
--- a/toke.c
+++ b/toke.c
@@ -7248,6 +7248,10 @@ Perl_yylex(pTHX)
 		UNIBRACK(OP_ENTEREVAL);
 	    }
 
+	case KEY_evalbytes:
+	    PL_expect = XTERM;
+	    UNIBRACK(-OP_ENTEREVAL);
+
 	case KEY_eof:
 	    UNI(OP_EOF);