"while($x=<>) no longer warns (implicit defined added)"

Msg-ID:  <199805051035.LAA27365@pluto.tiuk.ti.com>
 Files:  MANIFEST op.c t/op/defins.t

p4raw-id: //depot/maint-5.004/perl@949

3 files changed, 182 insertions, 1 deletions

diff --git a/MANIFEST b/MANIFEST
index 6dc628701a..f3208c4bce 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -713,6 +713,7 @@ t/op/chop.t		See if chop works
 t/op/closure.t		See if closures work
 t/op/cmp.t		See if the various string and numeric compare work
 t/op/cond.t		See if conditional expressions work
+t/op/defins.t		See if auto-insert of defined() works
 t/op/delete.t		See if delete works
 t/op/die_exit.t		See if die and exit status interaction works
 t/op/do.t		See if subroutines work
diff --git a/op.c b/op.c
index f3e8ab758a..c8098fb93d 100644
--- a/op.c
+++ b/op.c
@@ -2648,7 +2648,7 @@ OP** otherp;
 	case OP_NULL:
 	    if (k2 && k2->op_type == OP_READLINE
 		  && (k2->op_flags & OPf_STACKED)
-		  && (k1->op_type == OP_RV2SV || k1->op_type == OP_PADSV))
+		  && ((k1->op_flags & OPf_WANT) == OPf_WANT_SCALAR)) 
 		warnop = k2->op_type;
 	    break;
 
@@ -2818,6 +2818,24 @@ OP *block;
 	    || (expr->op_type == OP_NULL && expr->op_targ == OP_GLOB)) {
 	    expr = newUNOP(OP_DEFINED, 0,
 		newASSIGNOP(0, newSVREF(newGVOP(OP_GV, 0, defgv)), 0, expr) );
+	} else if (expr->op_flags & OPf_KIDS) {
+	    OP *k1 = ((UNOP*)expr)->op_first;
+	    OP *k2 = (k1) ? k1->op_sibling : NULL;
+	    switch (expr->op_type) {
+	      case OP_NULL: 
+		if (k2 && k2->op_type == OP_READLINE
+		      && (k2->op_flags & OPf_STACKED)
+		      && ((k1->op_flags & OPf_WANT) == OPf_WANT_SCALAR)) 
+		    expr = newUNOP(OP_DEFINED, 0, expr);
+		break;                                
+
+	      case OP_SASSIGN:
+		if (k1->op_type == OP_READDIR
+		      || k1->op_type == OP_GLOB
+		      || k1->op_type == OP_EACH)
+		    expr = newUNOP(OP_DEFINED, 0, expr);
+		break;
+	    }
 	}
     }
 
@@ -2859,6 +2877,24 @@ OP *cont;
 		 || (expr->op_type == OP_NULL && expr->op_targ == OP_GLOB))) {
 	expr = newUNOP(OP_DEFINED, 0,
 	    newASSIGNOP(0, newSVREF(newGVOP(OP_GV, 0, defgv)), 0, expr) );
+    } else if (expr && (expr->op_flags & OPf_KIDS)) {
+	OP *k1 = ((UNOP*)expr)->op_first;
+	OP *k2 = (k1) ? k1->op_sibling : NULL;
+	switch (expr->op_type) {
+	  case OP_NULL: 
+	    if (k2 && k2->op_type == OP_READLINE
+		  && (k2->op_flags & OPf_STACKED)
+		  && ((k1->op_flags & OPf_WANT) == OPf_WANT_SCALAR)) 
+		expr = newUNOP(OP_DEFINED, 0, expr);
+	    break;                                
+
+	  case OP_SASSIGN:
+	    if (k1->op_type == OP_READDIR
+		  || k1->op_type == OP_GLOB
+		  || k1->op_type == OP_EACH)
+		expr = newUNOP(OP_DEFINED, 0, expr);
+	    break;
+	}
     }
 
     if (!block)
diff --git a/t/op/defins.t b/t/op/defins.t
new file mode 100755
index 0000000000..5dd614d4b8
--- /dev/null
+++ b/t/op/defins.t
@@ -0,0 +1,144 @@
+#!./perl -w
+
+#
+# test auto defined() test insertion
+#
+
+BEGIN {
+    chdir 't' if -d 't';
+    @INC = '../lib';
+    $SIG{__WARN__} = sub { $warns++; warn $_[0] };
+    print "1..14\n";
+}
+    
+print "not " if $warns;
+print "ok 1\n";
+
+open(FILE,">./0");
+print FILE "1\n";
+print FILE "0";
+close(FILE);
+
+open(FILE,"<./0");
+my $seen = 0;
+my $dummy;
+while (my $name = <FILE>)
+ {
+  $seen++ if $name eq '0';
+ }            
+print "not " unless $seen;
+print "ok 2\n";
+
+seek(FILE,0,0);
+$seen = 0;
+my $line = '';
+do 
+ {
+  $seen++ if $line eq '0';
+ } while ($line = <FILE>);
+
+print "not " unless $seen;
+print "ok 3\n";
+
+
+seek(FILE,0,0);
+$seen = 0;    
+while (($seen ? $dummy : $name) = <FILE>)
+ {
+  $seen++ if $name eq '0';
+ }
+print "not " unless $seen;
+print "ok 4\n";
+
+seek(FILE,0,0);
+$seen = 0;    
+my %where;    
+while ($where{$seen} = <FILE>)
+ {
+  $seen++ if $where{$seen} eq '0';
+ }
+print "not " unless $seen;
+print "ok 5\n";
+
+opendir(DIR,'.');
+$seen = 0;
+while (my $name = readdir(DIR))
+ {
+  $seen++ if $name eq '0';
+ }            
+print "not " unless $seen;
+print "ok 6\n";
+
+rewinddir(DIR);
+$seen = 0;    
+$dummy = '';
+while (($seen ? $dummy : $name) = readdir(DIR))
+ {
+  $seen++ if $name eq '0';
+ }
+print "not " unless $seen;
+print "ok 7\n";
+
+rewinddir(DIR);
+$seen = 0;    
+while ($where{$seen} = readdir(DIR))
+ {
+  $seen++ if $where{$seen} eq '0';
+ }
+print "not " unless $seen;
+print "ok 8\n";
+
+$seen = 0;
+while (my $name = glob('*'))
+ {
+  $seen++ if $name eq '0';
+ }            
+print "not " unless $seen;
+print "ok 9\n";
+
+$seen = 0;    
+$dummy = '';
+while (($seen ? $dummy : $name) = glob('*'))
+ {
+  $seen++ if $name eq '0';
+ }
+print "not " unless $seen;
+print "ok 10\n";
+
+$seen = 0;    
+while ($where{$seen} = glob('*'))
+ {
+  $seen++ if $where{$seen} eq '0';
+ }
+print "not " unless $seen;
+print "ok 11\n";
+
+unlink("./0");
+
+my %hash = (0 => 1, 1 => 2);
+
+$seen = 0;
+while (my $name = each %hash)
+ {
+  $seen++ if $name eq '0';
+ }            
+print "not " unless $seen;
+print "ok 12\n";
+
+$seen = 0;    
+$dummy = '';
+while (($seen ? $dummy : $name) = each %hash)
+ {
+  $seen++ if $name eq '0';
+ }
+print "not " unless $seen;
+print "ok 13\n";
+
+$seen = 0;    
+while ($where{$seen} = each %hash)
+ {
+  $seen++ if $where{$seen} eq '0';
+ }
+print "not " unless $seen;
+print "ok 14\n";
+