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diff --git a/upstream/debian-bookworm/man1/perldeprecation.1 b/upstream/debian-bookworm/man1/perldeprecation.1 new file mode 100644 index 00000000..c0575a4c --- /dev/null +++ b/upstream/debian-bookworm/man1/perldeprecation.1 @@ -0,0 +1,691 @@ +.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.43) +.\" +.\" Standard preamble: +.\" ======================================================================== +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R +.fi +.. +.\" Set up some character translations and predefined strings. \*(-- will +.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left +.\" double quote, and \*(R" will give a right double quote. \*(C+ will +.\" give a nicer C++. Capital omega is used to do unbreakable dashes and +.\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, +.\" nothing in troff, for use with C<>. +.tr \(*W- +.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' +.ie n \{\ +. ds -- \(*W- +. ds PI pi +. if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch +. if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch +. ds L" "" +. ds R" "" +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. ds -- \|\(em\| +. ds PI \(*p +. ds L" `` +. ds R" '' +. ds C` +. ds C' +'br\} +.\" +.\" Escape single quotes in literal strings from groff's Unicode transform. +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" +.\" If the F register is >0, we'll generate index entries on stderr for +.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index +.\" entries marked with X<> in POD. Of course, you'll have to process the +.\" output yourself in some meaningful fashion. +.\" +.\" Avoid warning from groff about undefined register 'F'. +.de IX +.. +.nr rF 0 +.if \n(.g .if rF .nr rF 1 +.if (\n(rF:(\n(.g==0)) \{\ +. if \nF \{\ +. de IX +. tm Index:\\$1\t\\n%\t"\\$2" +.. +. if !\nF==2 \{\ +. nr % 0 +. nr F 2 +. \} +. \} +.\} +.rr rF +.\" ======================================================================== +.\" +.IX Title "PERLDEPRECATION 1" +.TH PERLDEPRECATION 1 "2023-11-25" "perl v5.36.0" "Perl Programmers Reference Guide" +.\" For nroff, turn off justification. Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. +.if n .ad l +.nh +.SH "NAME" +perldeprecation \- list Perl deprecations +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +The purpose of this document is to document what has been deprecated +in Perl, and by which version the deprecated feature will disappear, +or, for already removed features, when it was removed. +.PP +This document will try to discuss what alternatives for the deprecated +features are available. +.PP +The deprecated features will be grouped by the version of Perl in +which they will be removed. +.SS "Perl 5.40" +.IX Subsection "Perl 5.40" +\fIDowngrading a \f(CI\*(C`use VERSION\*(C'\fI to below v5.11\fR +.IX Subsection "Downgrading a use VERSION to below v5.11" +.PP +Once Perl has seen a \f(CW\*(C`use VERSION\*(C'\fR declaration that requests a version +\&\f(CW\*(C`v5.11\*(C'\fR or above, a subsequent second declaration that requests an earlier +version will print a deprecation warning. For example, +.PP +.Vb 2 +\& use v5.14; +\& say "We can use v5.14\*(Aqs features here"; +\& +\& use v5.10; # This prints a warning +.Ve +.PP +This behaviour will be removed in Perl 5.40; such a subsequent request will +become a compile-time error. +.PP +This is because of an intended related change to the interaction between +\&\f(CW\*(C`use VERSION\*(C'\fR and \f(CW\*(C`use strict\*(C'\fR. If you specify a version >= 5.11, strict is +enabled implicitly. If you request a version < 5.11, strict will become +disabled \fIeven if you had previously written\fR \f(CW\*(C`use strict\*(C'\fR. This was not +the previous behaviour of \f(CW\*(C`use VERSION\*(C'\fR, which at present will track +explicitly-enabled strictness flags independently. +.SS "Perl 5.38" +.IX Subsection "Perl 5.38" +\fIPod::Html utility functions\fR +.IX Subsection "Pod::Html utility functions" +.PP +The definition and documentation of three utility functions previously +importable from Pod::Html were moved to new package Pod::Html::Util in +Perl 5.36. While they remain importable from Pod::Html in Perl 5.36, as of +Perl 5.38 they will only be importable, on request, from Pod::Html::Util. +.SS "Perl 5.34" +.IX Subsection "Perl 5.34" +There are no deprecations or fatalizations scheduled for Perl 5.34. +.SS "Perl 5.32" +.IX Subsection "Perl 5.32" +\fIConstants from lexical variables potentially modified elsewhere\fR +.IX Subsection "Constants from lexical variables potentially modified elsewhere" +.PP +You wrote something like +.PP +.Vb 2 +\& my $var; +\& $sub = sub () { $var }; +.Ve +.PP +but \f(CW$var\fR is referenced elsewhere and could be modified after the \f(CW\*(C`sub\*(C'\fR +expression is evaluated. Either it is explicitly modified elsewhere +(\f(CW\*(C`$var = 3\*(C'\fR) or it is passed to a subroutine or to an operator like +\&\f(CW\*(C`printf\*(C'\fR or \f(CW\*(C`map\*(C'\fR, which may or may not modify the variable. +.PP +Traditionally, Perl has captured the value of the variable at that +point and turned the subroutine into a constant eligible for inlining. +In those cases where the variable can be modified elsewhere, this +breaks the behavior of closures, in which the subroutine captures +the variable itself, rather than its value, so future changes to the +variable are reflected in the subroutine's return value. +.PP +If you intended for the subroutine to be eligible for inlining, then +make sure the variable is not referenced elsewhere, possibly by +copying it: +.PP +.Vb 2 +\& my $var2 = $var; +\& $sub = sub () { $var2 }; +.Ve +.PP +If you do want this subroutine to be a closure that reflects future +changes to the variable that it closes over, add an explicit \f(CW\*(C`return\*(C'\fR: +.PP +.Vb 2 +\& my $var; +\& $sub = sub () { return $var }; +.Ve +.PP +This usage was deprecated and as of Perl 5.32 is no longer allowed. +.PP +\fIUse of strings with code points over 0xFF as arguments to \f(CI\*(C`vec\*(C'\fI\fR +.IX Subsection "Use of strings with code points over 0xFF as arguments to vec" +.PP +\&\f(CW\*(C`vec\*(C'\fR views its string argument as a sequence of bits. A string +containing a code point over 0xFF is nonsensical. This usage is +deprecated in Perl 5.28, and was removed in Perl 5.32. +.PP +\fIUse of code points over 0xFF in string bitwise operators\fR +.IX Subsection "Use of code points over 0xFF in string bitwise operators" +.PP +The string bitwise operators, \f(CW\*(C`&\*(C'\fR, \f(CW\*(C`|\*(C'\fR, \f(CW\*(C`^\*(C'\fR, and \f(CW\*(C`~\*(C'\fR, treat their +operands as strings of bytes. As such, values above 0xFF are +nonsensical. Some instances of these have been deprecated since Perl +5.24, and were made fatal in 5.28, but it turns out that in cases where +the wide characters did not affect the end result, no deprecation +notice was raised, and so remain legal. Now, all occurrences either are +fatal or raise a deprecation warning, so that the remaining legal +occurrences became fatal in 5.32. +.PP +An example of this is +.PP +.Vb 1 +\& "" & "\ex{100}" +.Ve +.PP +The wide character is not used in the \f(CW\*(C`&\*(C'\fR operation because the left +operand is shorter. This now throws an exception. +.PP +\fI\f(BIhostname()\fI doesn't accept any arguments\fR +.IX Subsection "hostname() doesn't accept any arguments" +.PP +The function \f(CW\*(C`hostname()\*(C'\fR in the Sys::Hostname module has always +been documented to be called with no arguments. Historically it has not +enforced this, and has actually accepted and ignored any arguments. As a +result, some users have got the mistaken impression that an argument does +something useful. To avoid these bugs, the function is being made strict. +Passing arguments was deprecated in Perl 5.28 and became fatal in Perl 5.32. +.PP +\fIUnescaped left braces in regular expressions\fR +.IX Subsection "Unescaped left braces in regular expressions" +.PP +The simple rule to remember, if you want to match a literal \f(CW\*(C`{\*(C'\fR +character (U+007B \f(CW\*(C`LEFT CURLY BRACKET\*(C'\fR) in a regular expression +pattern, is to escape each literal instance of it in some way. +Generally easiest is to precede it with a backslash, like \f(CW\*(C`\e{\*(C'\fR +or enclose it in square brackets (\f(CW\*(C`[{]\*(C'\fR). If the pattern +delimiters are also braces, any matching right brace (\f(CW\*(C`}\*(C'\fR) should +also be escaped to avoid confusing the parser, for example, +.PP +.Vb 1 +\& qr{abc\e{def\e}ghi} +.Ve +.PP +Forcing literal \f(CW\*(C`{\*(C'\fR characters to be escaped will enable the Perl +language to be extended in various ways in future releases. To avoid +needlessly breaking existing code, the restriction is not enforced in +contexts where there are unlikely to ever be extensions that could +conflict with the use there of \f(CW\*(C`{\*(C'\fR as a literal. A non-deprecation +warning that the left brace is being taken literally is raised in +contexts where there could be confusion about it. +.PP +Literal uses of \f(CW\*(C`{\*(C'\fR were deprecated in Perl 5.20, and some uses of it +started to give deprecation warnings since. These cases were made fatal +in Perl 5.26. Due to an oversight, not all cases of a use of a literal +\&\f(CW\*(C`{\*(C'\fR got a deprecation warning. Some cases started warning in Perl 5.26, +and were made fatal in Perl 5.30. Other cases started in Perl 5.28, +and were made fatal in 5.32. +.PP +\fIIn \s-1XS\s0 code, use of various macros dealing with \s-1UTF\-8.\s0\fR +.IX Subsection "In XS code, use of various macros dealing with UTF-8." +.PP +The macros below now require an extra parameter than in versions prior +to Perl 5.32. The final parameter in each one is a pointer into the +string supplied by the first parameter beyond which the input will not +be read. This prevents potential reading beyond the end of the buffer. +\&\f(CW\*(C`isALPHANUMERIC_utf8\*(C'\fR, +\&\f(CW\*(C`isASCII_utf8\*(C'\fR, +\&\f(CW\*(C`isBLANK_utf8\*(C'\fR, +\&\f(CW\*(C`isCNTRL_utf8\*(C'\fR, +\&\f(CW\*(C`isDIGIT_utf8\*(C'\fR, +\&\f(CW\*(C`isIDFIRST_utf8\*(C'\fR, +\&\f(CW\*(C`isPSXSPC_utf8\*(C'\fR, +\&\f(CW\*(C`isSPACE_utf8\*(C'\fR, +\&\f(CW\*(C`isVERTWS_utf8\*(C'\fR, +\&\f(CW\*(C`isWORDCHAR_utf8\*(C'\fR, +\&\f(CW\*(C`isXDIGIT_utf8\*(C'\fR, +\&\f(CW\*(C`isALPHANUMERIC_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isALPHA_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isASCII_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isBLANK_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isCNTRL_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isDIGIT_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isGRAPH_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isIDCONT_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isIDFIRST_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isLOWER_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isPRINT_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isPSXSPC_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isPUNCT_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isSPACE_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isUPPER_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isWORDCHAR_LC_utf8\*(C'\fR, +\&\f(CW\*(C`isXDIGIT_LC_utf8\*(C'\fR, +\&\f(CW\*(C`toFOLD_utf8\*(C'\fR, +\&\f(CW\*(C`toLOWER_utf8\*(C'\fR, +\&\f(CW\*(C`toTITLE_utf8\*(C'\fR, +and +\&\f(CW\*(C`toUPPER_utf8\*(C'\fR. +.PP +Since Perl 5.26, this functionality with the extra parameter has been +available by using a corresponding macro to each one of these, and whose +name is formed by appending \f(CW\*(C`_safe\*(C'\fR to the base name. There is no +change to the functionality of those. For example, \f(CW\*(C`isDIGIT_utf8_safe\*(C'\fR +corresponds to \f(CW\*(C`isDIGIT_utf8\*(C'\fR, and both now behave identically. All +are documented in \*(L"Character case changing\*(R" in perlapi and +\&\*(L"Character classification\*(R" in perlapi. +.PP +This change was originally scheduled for 5.30, but was delayed until +5.32. +.PP +\fI\f(CI\*(C`File::Glob::glob()\*(C'\fI was removed\fR +.IX Subsection "File::Glob::glob() was removed" +.PP +\&\f(CW\*(C`File::Glob\*(C'\fR has a function called \f(CW\*(C`glob\*(C'\fR, which just calls +\&\f(CW\*(C`bsd_glob\*(C'\fR. +.PP +\&\f(CW\*(C`File::Glob::glob()\*(C'\fR was deprecated in Perl 5.8. A deprecation +message was issued from Perl 5.26 onwards, the function became fatal +in Perl 5.30, and was removed entirely in Perl 5.32. +.PP +Code using \f(CW\*(C`File::Glob::glob()\*(C'\fR should call +\&\f(CW\*(C`File::Glob::bsd_glob()\*(C'\fR instead. +.SS "Perl 5.30" +.IX Subsection "Perl 5.30" +\fI\f(CI$*\fI is no longer supported\fR +.IX Subsection "$* is no longer supported" +.PP +Before Perl 5.10, setting \f(CW$*\fR to a true value globally enabled +multi-line matching within a string. This relique from the past lost +its special meaning in 5.10. Use of this variable became a fatal error +in Perl 5.30, freeing the variable up for a future special meaning. +.PP +To enable multiline matching one should use the \f(CW\*(C`/m\*(C'\fR regexp +modifier (possibly in combination with \f(CW\*(C`/s\*(C'\fR). This can be set +on a per match bases, or can be enabled per lexical scope (including +a whole file) with \f(CW\*(C`use re \*(Aq/m\*(Aq\*(C'\fR. +.PP +\fI\f(CI$#\fI is no longer supported\fR +.IX Subsection "$# is no longer supported" +.PP +This variable used to have a special meaning \*(-- it could be used +to control how numbers were formatted when printed. This seldom +used functionality was removed in Perl 5.10. In order to free up +the variable for a future special meaning, its use became a fatal +error in Perl 5.30. +.PP +To specify how numbers are formatted when printed, one is advised +to use \f(CW\*(C`printf\*(C'\fR or \f(CW\*(C`sprintf\*(C'\fR instead. +.PP +\fIAssigning non-zero to \f(CI$[\fI is fatal\fR +.IX Subsection "Assigning non-zero to $[ is fatal" +.PP +This variable (and the corresponding \f(CW\*(C`array_base\*(C'\fR feature and +arybase module) allowed changing the base for array and string +indexing operations. +.PP +Setting this to a non-zero value has been deprecated since Perl 5.12 and +throws a fatal error as of Perl 5.30. +.PP +\fI\f(CI\*(C`File::Glob::glob()\*(C'\fI will disappear\fR +.IX Subsection "File::Glob::glob() will disappear" +.PP +\&\f(CW\*(C`File::Glob\*(C'\fR has a function called \f(CW\*(C`glob\*(C'\fR, which just calls +\&\f(CW\*(C`bsd_glob\*(C'\fR. However, its prototype is different from the prototype +of \f(CW\*(C`CORE::glob\*(C'\fR, and hence, \f(CW\*(C`File::Glob::glob\*(C'\fR should not +be used. +.PP +\&\f(CW\*(C`File::Glob::glob()\*(C'\fR was deprecated in Perl 5.8. A deprecation +message was issued from Perl 5.26 onwards, and in Perl 5.30 this was +turned into a fatal error. +.PP +Code using \f(CW\*(C`File::Glob::glob()\*(C'\fR should call +\&\f(CW\*(C`File::Glob::bsd_glob()\*(C'\fR instead. +.PP +\fIUnescaped left braces in regular expressions (for 5.30)\fR +.IX Subsection "Unescaped left braces in regular expressions (for 5.30)" +.PP +See \*(L"Unescaped left braces in regular expressions\*(R" above. +.PP +\fIUnqualified \f(CI\*(C`dump()\*(C'\fI\fR +.IX Subsection "Unqualified dump()" +.PP +Use of \f(CW\*(C`dump()\*(C'\fR instead of \f(CW\*(C`CORE::dump()\*(C'\fR was deprecated in Perl 5.8, +and an unqualified \f(CW\*(C`dump()\*(C'\fR is no longer available as of Perl 5.30. +.PP +See \*(L"dump\*(R" in perlfunc. +.PP +\fIUsing \f(BImy()\fI in false conditional.\fR +.IX Subsection "Using my() in false conditional." +.PP +There has been a long-standing bug in Perl that causes a lexical variable +not to be cleared at scope exit when its declaration includes a false +conditional. Some people have exploited this bug to achieve a kind of +static variable. To allow us to fix this bug, people should not be +relying on this behavior. +.PP +Instead, it's recommended one uses \f(CW\*(C`state\*(C'\fR variables to achieve the +same effect: +.PP +.Vb 4 +\& use 5.10.0; +\& sub count {state $counter; return ++ $counter} +\& say count (); # Prints 1 +\& say count (); # Prints 2 +.Ve +.PP +\&\f(CW\*(C`state\*(C'\fR variables were introduced in Perl 5.10. +.PP +Alternatively, you can achieve a similar static effect by +declaring the variable in a separate block outside the function, e.g., +.PP +.Vb 1 +\& sub f { my $x if 0; return $x++ } +.Ve +.PP +becomes +.PP +.Vb 1 +\& { my $x; sub f { return $x++ } } +.Ve +.PP +The use of \f(CW\*(C`my()\*(C'\fR in a false conditional has been deprecated in +Perl 5.10, and became a fatal error in Perl 5.30. +.PP +\fIReading/writing bytes from/to :utf8 handles.\fR +.IX Subsection "Reading/writing bytes from/to :utf8 handles." +.PP +The \fBsysread()\fR, \fBrecv()\fR, \fBsyswrite()\fR and \fBsend()\fR operators are +deprecated on handles that have the \f(CW\*(C`:utf8\*(C'\fR layer, either explicitly, or +implicitly, eg., with the \f(CW\*(C`:encoding(UTF\-16LE)\*(C'\fR layer. +.PP +Both \fBsysread()\fR and \fBrecv()\fR currently use only the \f(CW\*(C`:utf8\*(C'\fR flag for the stream, +ignoring the actual layers. Since \fBsysread()\fR and \fBrecv()\fR do no \s-1UTF\-8\s0 +validation they can end up creating invalidly encoded scalars. +.PP +Similarly, \fBsyswrite()\fR and \fBsend()\fR use only the \f(CW\*(C`:utf8\*(C'\fR flag, otherwise ignoring +any layers. If the flag is set, both write the value \s-1UTF\-8\s0 encoded, even if +the layer is some different encoding, such as the example above. +.PP +Ideally, all of these operators would completely ignore the \f(CW\*(C`:utf8\*(C'\fR state, +working only with bytes, but this would result in silently breaking existing +code. To avoid this a future version of perl will throw an exception when +any of \fBsysread()\fR, \fBrecv()\fR, \fBsyswrite()\fR or \fBsend()\fR are called on handle with the +\&\f(CW\*(C`:utf8\*(C'\fR layer. +.PP +As of Perl 5.30, it is no longer be possible to use \fBsysread()\fR, \fBrecv()\fR, +\&\fBsyswrite()\fR or \fBsend()\fR to read or send bytes from/to :utf8 handles. +.PP +\fIUse of unassigned code point or non-standalone grapheme for a delimiter.\fR +.IX Subsection "Use of unassigned code point or non-standalone grapheme for a delimiter." +.PP +A grapheme is what appears to a native-speaker of a language to be a +character. In Unicode (and hence Perl) a grapheme may actually be +several adjacent characters that together form a complete grapheme. For +example, there can be a base character, like \*(L"R\*(R" and an accent, like a +circumflex \*(L"^\*(R", that appear to be a single character when displayed, +with the circumflex hovering over the \*(L"R\*(R". +.PP +As of Perl 5.30, use of delimiters which are non-standalone graphemes is +fatal, in order to move the language to be able to accept +multi-character graphemes as delimiters. +.PP +Also, as of Perl 5.30, delimiters which are unassigned code points +but that may someday become assigned are prohibited. Otherwise, code +that works today would fail to compile if the currently unassigned +delimiter ends up being something that isn't a stand-alone grapheme. +Because Unicode is never going to assign non-character code +points, nor code points that are +above the legal Unicode maximum, those can be delimiters. +.SS "Perl 5.28" +.IX Subsection "Perl 5.28" +\fIAttributes \f(CI\*(C`:locked\*(C'\fI and \f(CI\*(C`:unique\*(C'\fI\fR +.IX Subsection "Attributes :locked and :unique" +.PP +The attributes \f(CW\*(C`:locked\*(C'\fR (on code references) and \f(CW\*(C`:unique\*(C'\fR +(on array, hash and scalar references) have had no effect since +Perl 5.005 and Perl 5.8.8 respectively. Their use has been deprecated +since. +.PP +As of Perl 5.28, these attributes are syntax errors. Since the +attributes do not do anything, removing them from your code fixes +the syntax error; and removing them will not influence the behaviour +of your code. +.PP +\fIBare here-document terminators\fR +.IX Subsection "Bare here-document terminators" +.PP +Perl has allowed you to use a bare here-document terminator to have the +here-document end at the first empty line. This practise was deprecated +in Perl 5.000; as of Perl 5.28, using a bare here-document terminator +throws a fatal error. +.PP +You are encouraged to use the explicitly quoted form if you wish to +use an empty line as the terminator of the here-document: +.PP +.Vb 2 +\& print <<""; +\& Print this line. +\& +\& # Previous blank line ends the here\-document. +.Ve +.PP +\fISetting $/ to a reference to a non-positive integer\fR +.IX Subsection "Setting $/ to a reference to a non-positive integer" +.PP +You assigned a reference to a scalar to \f(CW$/\fR where the +referenced item is not a positive integer. In older perls this \fBappeared\fR +to work the same as setting it to \f(CW\*(C`undef\*(C'\fR but was in fact internally +different, less efficient and with very bad luck could have resulted in +your file being split by a stringified form of the reference. +.PP +In Perl 5.20.0 this was changed so that it would be \fBexactly\fR the same as +setting \f(CW$/\fR to undef, with the exception that this warning would be +thrown. +.PP +As of Perl 5.28, setting \f(CW$/\fR to a reference of a non-positive +integer throws a fatal error. +.PP +You are recommended to change your code to set \f(CW$/\fR to \f(CW\*(C`undef\*(C'\fR explicitly +if you wish to slurp the file. +.PP +\fILimit on the value of Unicode code points.\fR +.IX Subsection "Limit on the value of Unicode code points." +.PP +Unicode only allows code points up to 0x10FFFF, but Perl allows +much larger ones. Up till Perl 5.28, it was allowed to use code +points exceeding the maximum value of an integer (\f(CW\*(C`IV_MAX\*(C'\fR). +However, that did break the perl interpreter in some constructs, +including causing it to hang in a few cases. The known problem +areas were in \f(CW\*(C`tr///\*(C'\fR, regular expression pattern matching using +quantifiers, as quote delimiters in \f(CW\*(C`q\f(CIX\f(CW...\f(CIX\f(CW\*(C'\fR (where \fIX\fR is +the \f(CW\*(C`chr()\*(C'\fR of a large code point), and as the upper limits in +loops. +.PP +The use of out of range code points was deprecated in Perl 5.24; as of +Perl 5.28 using a code point exceeding \f(CW\*(C`IV_MAX\*(C'\fR throws a fatal error. +.PP +If your code is to run on various platforms, keep in mind that the upper +limit depends on the platform. It is much larger on 64\-bit word sizes +than 32\-bit ones. For 32\-bit integers, \f(CW\*(C`IV_MAX\*(C'\fR equals \f(CW0x7FFFFFFF\fR, +for 64\-bit integers, \f(CW\*(C`IV_MAX\*(C'\fR equals \f(CW0x7FFFFFFFFFFFFFFF\fR. +.PP +\fIUse of comma-less variable list in formats.\fR +.IX Subsection "Use of comma-less variable list in formats." +.PP +It was allowed to use a list of variables in a format, without +separating them with commas. This usage has been deprecated +for a long time, and as of Perl 5.28, this throws a fatal error. +.PP +\fIUse of \f(CI\*(C`\eN{}\*(C'\fI\fR +.IX Subsection "Use of N{}" +.PP +Use of \f(CW\*(C`\eN{}\*(C'\fR with nothing between the braces was deprecated in +Perl 5.24, and throws a fatal error as of Perl 5.28. +.PP +Since such a construct is equivalent to using an empty string, +you are recommended to remove such \f(CW\*(C`\eN{}\*(C'\fR constructs. +.PP +\fIUsing the same symbol to open a filehandle and a dirhandle\fR +.IX Subsection "Using the same symbol to open a filehandle and a dirhandle" +.PP +It used to be legal to use \f(CW\*(C`open()\*(C'\fR to associate both a +filehandle and a dirhandle to the same symbol (glob or scalar). +This idiom is likely to be confusing, and it was deprecated in +Perl 5.10. +.PP +Using the same symbol to \f(CW\*(C`open()\*(C'\fR a filehandle and a dirhandle +throws a fatal error as of Perl 5.28. +.PP +You should be using two different symbols instead. +.PP +\fI${^ENCODING} is no longer supported.\fR +.IX Subsection "${^ENCODING} is no longer supported." +.PP +The special variable \f(CW\*(C`${^ENCODING}\*(C'\fR was used to implement +the \f(CW\*(C`encoding\*(C'\fR pragma. Setting this variable to anything other +than \f(CW\*(C`undef\*(C'\fR was deprecated in Perl 5.22. Full deprecation +of the variable happened in Perl 5.25.3. +.PP +Setting this variable to anything other than an undefined value +throws a fatal error as of Perl 5.28. +.PP +\fI\f(CI\*(C`B::OP::terse\*(C'\fI\fR +.IX Subsection "B::OP::terse" +.PP +This method, which just calls \f(CW\*(C`B::Concise::b_terse\*(C'\fR, has been +deprecated, and disappeared in Perl 5.28. Please use +\&\f(CW\*(C`B::Concise\*(C'\fR instead. +.PP +\fIUse of inherited \s-1AUTOLOAD\s0 for non-method \f(CI%s::\fI%s() is no longer allowed\fR +.IX Subsection "Use of inherited AUTOLOAD for non-method %s::%s() is no longer allowed" +.PP +As an (ahem) accidental feature, \f(CW\*(C`AUTOLOAD\*(C'\fR subroutines were looked +up as methods (using the \f(CW@ISA\fR hierarchy) even when the subroutines +to be autoloaded were called as plain functions (e.g. \f(CW\*(C`Foo::bar()\*(C'\fR), +not as methods (e.g. \f(CW\*(C`Foo\->bar()\*(C'\fR or \f(CW\*(C`$obj\->bar()\*(C'\fR). +.PP +This bug was deprecated in Perl 5.004, has been rectified in Perl 5.28 +by using method lookup only for methods' \f(CW\*(C`AUTOLOAD\*(C'\fRs. +.PP +The simple rule is: Inheritance will not work when autoloading +non-methods. The simple fix for old code is: In any module that used +to depend on inheriting \f(CW\*(C`AUTOLOAD\*(C'\fR for non-methods from a base class +named \f(CW\*(C`BaseClass\*(C'\fR, execute \f(CW\*(C`*AUTOLOAD = \e&BaseClass::AUTOLOAD\*(C'\fR during +startup. +.PP +In code that currently says \f(CW\*(C`use AutoLoader; @ISA = qw(AutoLoader);\*(C'\fR +you should remove AutoLoader from \f(CW@ISA\fR and change \f(CW\*(C`use AutoLoader;\*(C'\fR to +\&\f(CW\*(C`use AutoLoader \*(AqAUTOLOAD\*(Aq;\*(C'\fR. +.PP +\fIUse of code points over 0xFF in string bitwise operators\fR +.IX Subsection "Use of code points over 0xFF in string bitwise operators" +.PP +The string bitwise operators, \f(CW\*(C`&\*(C'\fR, \f(CW\*(C`|\*(C'\fR, \f(CW\*(C`^\*(C'\fR, and \f(CW\*(C`~\*(C'\fR, treat +their operands as strings of bytes. As such, values above 0xFF +are nonsensical. Using such code points with these operators +was deprecated in Perl 5.24, and is fatal as of Perl 5.28. +.PP +\fIIn \s-1XS\s0 code, use of \f(CI\*(C`to_utf8_case()\*(C'\fI\fR +.IX Subsection "In XS code, use of to_utf8_case()" +.PP +This function has been removed as of Perl 5.28; instead convert to call +the appropriate one of: +\&\f(CW\*(C`toFOLD_utf8_safe\*(C'\fR. +\&\f(CW\*(C`toLOWER_utf8_safe\*(C'\fR, +\&\f(CW\*(C`toTITLE_utf8_safe\*(C'\fR, +or +\&\f(CW\*(C`toUPPER_utf8_safe\*(C'\fR. +.SS "Perl 5.26" +.IX Subsection "Perl 5.26" +\fI\f(CI\*(C`\-\-libpods\*(C'\fI in \f(CI\*(C`Pod::Html\*(C'\fI\fR +.IX Subsection "--libpods in Pod::Html" +.PP +Since Perl 5.18, the option \f(CW\*(C`\-\-libpods\*(C'\fR has been deprecated, and +using this option did not do anything other than producing a warning. +.PP +The \f(CW\*(C`\-\-libpods\*(C'\fR option is no longer recognized as of Perl 5.26. +.PP +\fIThe utilities \f(CI\*(C`c2ph\*(C'\fI and \f(CI\*(C`pstruct\*(C'\fI\fR +.IX Subsection "The utilities c2ph and pstruct" +.PP +These old, perl3\-era utilities have been deprecated in favour of +\&\f(CW\*(C`h2xs\*(C'\fR for a long time. As of Perl 5.26, they have been removed. +.PP +\fITrapping \f(CI\*(C`$SIG {_\|_DIE_\|_}\*(C'\fI other than during program exit.\fR +.IX Subsection "Trapping $SIG {__DIE__} other than during program exit." +.PP +The \f(CW$SIG{_\|_DIE_\|_}\fR hook is called even inside an \f(CW\*(C`eval()\*(C'\fR. It was +never intended to happen this way, but an implementation glitch made +this possible. This used to be deprecated, as it allowed strange action +at a distance like rewriting a pending exception in \f(CW$@\fR. Plans to +rectify this have been scrapped, as users found that rewriting a +pending exception is actually a useful feature, and not a bug. +.PP +Perl never issued a deprecation warning for this; the deprecation +was by documentation policy only. But this deprecation has been +lifted as of Perl 5.26. +.PP +\fIMalformed \s-1UTF\-8\s0 string in \*(L"%s\*(R"\fR +.IX Subsection "Malformed UTF-8 string in %s" +.PP +This message indicates a bug either in the Perl core or in \s-1XS\s0 +code. Such code was trying to find out if a character, allegedly +stored internally encoded as \s-1UTF\-8,\s0 was of a given type, such as +being punctuation or a digit. But the character was not encoded +in legal \s-1UTF\-8.\s0 The \f(CW%s\fR is replaced by a string that can be used +by knowledgeable people to determine what the type being checked +against was. +.PP +Passing malformed strings was deprecated in Perl 5.18, and +became fatal in Perl 5.26. +.SS "Perl 5.24" +.IX Subsection "Perl 5.24" +\fIUse of \f(CI*glob{FILEHANDLE}\fI\fR +.IX Subsection "Use of *glob{FILEHANDLE}" +.PP +The use of \f(CW*glob{FILEHANDLE}\fR was deprecated in Perl 5.8. +The intention was to use \f(CW*glob{IO}\fR instead, for which +\&\f(CW*glob{FILEHANDLE}\fR is an alias. +.PP +However, this feature was undeprecated in Perl 5.24. +.PP +\fICalling POSIX::%s() is deprecated\fR +.IX Subsection "Calling POSIX::%s() is deprecated" +.PP +The following functions in the \f(CW\*(C`POSIX\*(C'\fR module are no longer available: +\&\f(CW\*(C`isalnum\*(C'\fR, \f(CW\*(C`isalpha\*(C'\fR, \f(CW\*(C`iscntrl\*(C'\fR, \f(CW\*(C`isdigit\*(C'\fR, \f(CW\*(C`isgraph\*(C'\fR, \f(CW\*(C`islower\*(C'\fR, +\&\f(CW\*(C`isprint\*(C'\fR, \f(CW\*(C`ispunct\*(C'\fR, \f(CW\*(C`isspace\*(C'\fR, \f(CW\*(C`isupper\*(C'\fR, and \f(CW\*(C`isxdigit\*(C'\fR. The +functions are buggy and don't work on \s-1UTF\-8\s0 encoded strings. See their +entries in \s-1POSIX\s0 for more information. +.PP +The functions were deprecated in Perl 5.20, and removed in Perl 5.24. +.SS "Perl 5.16" +.IX Subsection "Perl 5.16" +\fIUse of \f(CI%s\fI on a handle without * is deprecated\fR +.IX Subsection "Use of %s on a handle without * is deprecated" +.PP +It used to be possible to use \f(CW\*(C`tie\*(C'\fR, \f(CW\*(C`tied\*(C'\fR or \f(CW\*(C`untie\*(C'\fR on a scalar +while the scalar holds a typeglob. This caused its filehandle to be +tied. It left no way to tie the scalar itself when it held a typeglob, +and no way to untie a scalar that had had a typeglob assigned to it. +.PP +This was deprecated in Perl 5.14, and the bug was fixed in Perl 5.16. +.PP +So now \f(CW\*(C`tie $scalar\*(C'\fR will always tie the scalar, not the handle it holds. +To tie the handle, use \f(CW\*(C`tie *$scalar\*(C'\fR (with an explicit asterisk). The same +applies to \f(CW\*(C`tied *$scalar\*(C'\fR and \f(CW\*(C`untie *$scalar\*(C'\fR. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +warnings, diagnostics. |