It helps to actually add the files you add to MANIFEST. (Thanks Dave

for spotting my mistake).

p4raw-id: //depot/perl@27616

diff --git a/t/comp/fold.t b/t/comp/fold.t
new file mode 100644 (file)
index 0000000..f063c20
--- /dev/null
+++ b/t/comp/fold.t
@@ -0,0 +1,38 @@
+#!./perl
+
+BEGIN {
+    chdir 't';
+    @INC = '../lib';
+    require './test.pl';
+}
+use strict;
+use warnings;
+
+plan (8);
+
+# Historically constant folding was performed by evaluating the ops, and if
+# they threw an exception compilation failed. This was seen as buggy, because
+# even illegal constants in unreachable code would cause failure. So now
+# illegal expressions are reported at runtime, if the expression is reached,
+# making constant folding consistent with many other languages, and purely an
+# optimisation rather than a behaviour change.
+
+my $a;
+$a = eval '$b = 0/0 if 0; 3';
+is ($a, 3);
+is ($@, "");
+
+my $b = 0;
+$a = eval 'if ($b) {return sqrt -3} 3';
+is ($a, 3);
+is ($@, "");
+
+$a = eval q{
+       $b = eval q{if ($b) {return log 0} 4};
+       is ($b, 4);
+       is ($@, "");
+       5;
+};
+is ($a, 5);
+is ($@, "");
+