#!./perl # $RCSfile: repeat.t,v $$Revision: 4.1 $$Date: 92/08/07 18:28:21 $ print "1..20\n"; # compile time if ('-' x 5 eq '-----') {print "ok 1\n";} else {print "not ok 1\n";} if ('-' x 1 eq '-') {print "ok 2\n";} else {print "not ok 2\n";} if ('-' x 0 eq '') {print "ok 3\n";} else {print "not ok 3\n";} if ('ab' x 3 eq 'ababab') {print "ok 4\n";} else {print "not ok 4\n";} # run time $a = '-'; if ($a x 5 eq '-----') {print "ok 5\n";} else {print "not ok 5\n";} if ($a x 1 eq '-') {print "ok 6\n";} else {print "not ok 6\n";} if ($a x 0 eq '') {print "ok 7\n";} else {print "not ok 7\n";} $a = 'ab'; if ($a x 3 eq 'ababab') {print "ok 8\n";} else {print "not ok 8\n";} $a = 'xyz'; $a x= 2; if ($a eq 'xyzxyz') {print "ok 9\n";} else {print "not ok 9\n";} $a x= 1; if ($a eq 'xyzxyz') {print "ok 10\n";} else {print "not ok 10\n";} $a x= 0; if ($a eq '') {print "ok 11\n";} else {print "not ok 11\n";} @x = (1,2,3); print join('', @x x 4) eq '3333' ? "ok 12\n" : "not ok 12\n"; print join('', (@x) x 4) eq '123123123123' ? "ok 13\n" : "not ok 13\n"; print join('', (@x,()) x 4) eq '123123123123' ? "ok 14\n" : "not ok 14\n"; print join('', (@x,1) x 4) eq '1231123112311231' ? "ok 15\n" : "not ok 15\n"; print join(':', () x 4) eq '' ? "ok 16\n" : "not ok 16\n"; print join(':', (9) x 4) eq '9:9:9:9' ? "ok 17\n" : "not ok 17\n"; print join(':', (9,9) x 4) eq '9:9:9:9:9:9:9:9' ? "ok 18\n" : "not ok 18\n"; print join('', (split(//,"123")) x 2) eq '123123' ? "ok 19\n" : "not ok 19\n"; # # The test #20 is actually testing for Digital C compiler optimizer bug. # # Dec C versions 5.* and 6.0 (used in Digital UNIX and VMS) used # to produce (as of December 1998) broken code for util.c:repeatcpy() # (a utility function for the 'x' operator) in the case *all* these # four conditions held: # # (1) len == 1 # (2) "from" had the 8th bit on in its single character # (3) count > 7 (the 'x' count > 16) # (4) the highest optimization level was used in compilation # (which is the default when compiling Perl) # # The bug looked like this (. being the eight-bit character and ? being \xff): # # 16 ................ # 17 .........???????. # 18 .........???????.. # 19 .........???????... # 20 .........???????.... # 21 .........???????..... # 22 .........???????...... # 23 .........???????....... # 24 .........???????.??????? # 25 .........???????.???????. # # The bug could be (obscurely) avoided by changing "from" to # be an unsigned char pointer. # # The bug was triggered in the "if (len == 1)" branch. The fix # was to introduce a new temporary variable. In diff -u format: # # register char *frombase = from; # # if (len == 1) { #- todo = *from; #+ register char c = *from; # while (count-- > 0) #- *to++ = todo; #+ *to++ = c; # return; # } # # This obscure bug was not found by the then test suite but instead # by Mark.Martinec@nsc.ijs.si while trying to install Digest-MD5-2.00. # # jhi@iki.fi # print "\xdd" x 24 eq "\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd\xdd" ? "ok 20\n" : "not ok 20\n";