1B::Hooks::EndOfScope(3)User Contributed Perl DocumentatioBn::Hooks::EndOfScope(3)
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6 B::Hooks::EndOfScope - Execute code after a scope finished compilation
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9 version 0.26
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12 on_scope_end { ... };
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15 This module allows you to execute code when perl finished compiling the
16 surrounding scope.
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19 on_scope_end
20 on_scope_end { ... };
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22 on_scope_end $code;
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24 Registers $code to be executed after the surrounding scope has been
25 compiled.
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27 This is exported by default. See Sub::Exporter on how to customize it.
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30 Pure-perl mode caveat
31 This caveat applies to any version of perl where Variable::Magic is
32 unavailable or otherwise disabled.
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34 While Variable::Magic has access to some very dark sorcery to make it
35 possible to throw an exception from within a callback, the pure-perl
36 implementation does not have access to these hacks. Therefore, what
37 would have been a compile-time exception is instead converted to a
38 warning, and your execution will continue as if the exception never
39 happened.
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41 To explicitly request an XS (or PP) implementation one has two choices.
42 Either to import from the desired implementation explicitly:
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44 use B::Hooks::EndOfScope::XS
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46 use B::Hooks::EndOfScope::PP
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48 or by setting $ENV{B_HOOKS_ENDOFSCOPE_IMPLEMENTATION} to either "XS" or
49 "PP".
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51 Perl 5.8.0 ~ 5.8.3
52 Due to a core interpreter bug
53 <https://rt.perl.org/Public/Bug/Display.html?id=27040#txn-82797>
54 present in older perl versions, the implementation of
55 B::Hooks::EndOfScope deliberately leaks a single empty hash for every
56 scope being cleaned. This is done to avoid the memory corruption
57 associated with the bug mentioned above.
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59 In order to stabilize this workaround use of Variable::Magic is
60 disabled on perls prior to version 5.8.4. On such systems
61 loading/requesting B::Hooks::EndOfScope::XS explicitly will result in a
62 compile-time exception.
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64 Perl versions 5.6.x
65 Versions of perl before 5.8.0 lack a feature allowing changing the
66 visibility of "%^H" via setting bit 17 within $^H. As such the only way
67 to achieve the effect necessary for this module to work, is to use the
68 "local" operator explicitly on these platforms. This might lead to
69 unexpected interference with other scope-driven libraries relying on
70 the same mechanism. On the flip side there are no such known
71 incompatibilities at the time this note was written.
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73 For further details on the unavailable behavior please refer to the
74 test file t/02-localise.t included with the distribution.
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77 Sub::Exporter
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79 Variable::Magic
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82 Bugs may be submitted through the RT bug tracker
83 <https://rt.cpan.org/Public/Dist/Display.html?Name=B-Hooks-EndOfScope>
84 (or bug-B-Hooks-EndOfScope@rt.cpan.org <mailto:bug-B-Hooks-
85 EndOfScope@rt.cpan.org>).
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88 • Florian Ragwitz <rafl@debian.org>
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90 • Peter Rabbitson <ribasushi@leporine.io>
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93 • Karen Etheridge <ether@cpan.org>
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95 • Christian Walde <walde.christian@googlemail.com>
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97 • Graham Knop <haarg@haarg.org>
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99 • Simon Wilper <sxw@chronowerks.de>
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101 • Tatsuhiko Miyagawa <miyagawa@bulknews.net>
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103 • Tomas Doran <bobtfish@bobtfish.net>
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106 This software is copyright (c) 2008 by Florian Ragwitz.
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108 This is free software; you can redistribute it and/or modify it under
109 the same terms as the Perl 5 programming language system itself.
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113perl v5.36.0 2022-07-22 B::Hooks::EndOfScope(3)