X-Git-Url: http://git.vpit.fr/?p=perl%2Fmodules%2Findirect.git;a=blobdiff_plain;f=lib%2Findirect.pm;h=ff3d34e02b2e8ad8f608f9b22d715a3dcfcad414;hp=c068be73fa8e42e43bbf961f4343ff698cc3c1ec;hb=c88f53009246bbc1af1789f746acc5d841fc0ae8;hpb=12f5aa96d0f4d2275aafa29bc76c96a0d4f215a9 diff --git a/lib/indirect.pm b/lib/indirect.pm index c068be7..ff3d34e 100644 --- a/lib/indirect.pm +++ b/lib/indirect.pm @@ -1,6 +1,6 @@ package indirect; -use 5.008; +use 5.008001; use strict; use warnings; @@ -11,78 +11,228 @@ indirect - Lexically warn about using the indirect object syntax. =head1 VERSION -Version 0.11 +Version 0.25 =cut our $VERSION; BEGIN { - $VERSION = '0.11'; + $VERSION = '0.25'; } =head1 SYNOPSIS + # In a script no indirect; my $x = new Apple 1, 2, 3; # warns { use indirect; my $y = new Pear; # ok + { + no indirect hook => sub { + die "You really wanted $_[0]\->$_[1] at $_[2]:$_[3]" + }; + # croaks 'You really wanted Pineapple->new at blurp.pm:13' + my $z = new Pineapple 'fresh'; + } } - no indirect ':fatal'; + try { ... }; # warns + + no indirect ':fatal'; # or 'FATAL', or ':Fatal' ... if (defied $foo) { ... } # croaks, note the typo + # Globally enabled from the command-line + perl -M-indirect=global -e 'my $x = new Banana;' # warns + + # Or globally enabled each time perl is executed + export PERL5OPT="-M-indirect=global" + perl -e 'my $y = new Coconut;' # warns + =head1 DESCRIPTION -When enabled (or disabled as some may prefer to say, since you actually turn it on by calling C), this pragma warns about indirect object syntax constructs that may have slipped into your code. This syntax is now considered harmful, since its parsing has many quirks and its use is error prone (when C isn't defined, C is actually interpreted as C<< $x->sub >>). +When enabled (or disabled as some may prefer to say, since you actually turn it on by calling C), this pragma warns about indirect object syntax constructs that may have slipped into your code. + +This syntax is now considered harmful, since its parsing has many quirks and its use is error prone (when C is not defined, C actually compiles to C<< $x->swoosh >>). +In L, Matt S. Trout gives an example of an indirect construct that can cause a particularly bewildering error. -It currently does not warn when the object is enclosed between braces (like C) or for core functions (C or C). This may change in the future, or may be added as optional features that would be enabled by passing options to C. +It currently does not warn for core functions (C, C, C or C). +This may change in the future, or may be added as optional features that would be enabled by passing options to C. This module is B a source filter. +=cut + +BEGIN { + if ($ENV{PERL_INDIRECT_PM_DISABLE}) { + *_tag = sub ($) { 1 }; + *I_THREADSAFE = sub () { 1 }; + *I_FORKSAFE = sub () { 1 }; + } else { + require XSLoader; + XSLoader::load(__PACKAGE__, $VERSION); + } +} + =head1 METHODS -=head2 C +=head2 C<< unimport [ 'global', hook => $hook | 'fatal' ] >> -Magically called when C is encountered. Turns the module on. If C<@opts> contains C<':fatal'>, the module will croak on the first indirect syntax met. +Magically called when C is encountered. +Turns the module on. +The policy to apply depends on what is first found in C<@opts> : -=head2 C +=over 4 -Magically called at each C. Turns the module off. +=item * + +If it is a string that matches C, the compilation will croak on the first indirect syntax met. + +=item * + +If the key/value pair C<< hook => $hook >> comes first, C<$hook> will be called for each error with a string representation of the object as C<$_[0]>, the method name as C<$_[1]>, the current file as C<$_[2]> and the line number as C<$_[3]>. +If and only if the object is actually a block, C<$_[0]> is assured to start by C<'{'>. + +=item * + +If none of C and C are specified, a warning will be emitted for each indirect construct. + +=item * + +If C<@opts> contains a string that matches C, the pragma will be globally enabled for B code compiled after the current C statement, except for code that is in the lexical scope of C. +This option may come indifferently before or after the C or C options, in the case they are also passed to L. + +The global policy applied is the one resulting of the C or C options, thus defaults to a warning when none of those are specified : + + no indirect 'global'; # warn for any indirect call + no indirect qw; # die on any indirect call + no indirect 'global', hook => \&hook # custom global action + +Note that if another policy is installed by a C statement further in the code, it will overrule the global policy : + + no indirect 'global'; # warn globally + { + no indirect 'fatal'; # throw exceptions for this lexical scope + ... + require Some::Module; # the global policy will apply for the + # compilation phase of this module + } + +=back =cut -BEGIN { - require XSLoader; - XSLoader::load(__PACKAGE__, $VERSION); -} +sub unimport { + shift; + + my $hook; + my $global; + while (@_) { + my $arg = shift; + if ($arg eq 'hook') { + last if $hook; + $hook = shift; + } elsif ($arg =~ /^:?fatal$/i) { + last if $hook; + $hook = sub { die msg(@_) }; + } elsif ($arg =~ /^:?global$/i) { + $global = 1; + } + } + $hook = sub { warn msg(@_) } unless defined $hook; -sub import { - $^H{+(__PACKAGE__)} = undef; - (); + $^H |= 0x00020000; + if ($global) { + delete $^H{+(__PACKAGE__)}; + _global($hook); + } else { + $^H{+(__PACKAGE__)} = _tag($hook); + } + + return; } -my $msg = sub { "Indirect call of method \"$_[1]\" on object \"$_[0]\"" }; +=head2 C -sub unimport { - (undef, my $type) = @_; +Magically called at each C. Turns the module off. + +As explained in L's description, an C statement will lexically override a global policy previously installed by C (if there's one). + +=cut + +sub import { $^H |= 0x00020000; - my $cb = (defined $type and $type eq ':fatal') - ? sub { die $msg->(@_) } - : sub { warn $msg->(@_) }; - $^H{+(__PACKAGE__)} = _tag($cb); - (); + $^H{+(__PACKAGE__)} = _tag(undef); + + return; } +=head1 FUNCTIONS + +=head2 C + +Returns the default error message generated by C when an invalid construct is reported. + +=cut + +sub msg { + my $obj = $_[0]; + + join ' ', "Indirect call of method \"$_[1]\" on", + ($obj =~ /^\s*\{/ ? "a block" : "object \"$obj\""), + "at $_[2] line $_[3].\n"; +}; + +=head1 CONSTANTS + +=head2 C + +True iff the module could have been built with thread-safety features enabled. + +=head2 C + +True iff this module could have been built with fork-safety features enabled. +This will always be true except on Windows where it's false for perl 5.10.0 and below . + +=head1 DIAGNOSTICS + +=head2 C + +The default warning/exception message thrown when an indirect call on an object is found. + +=head2 C + +The default warning/exception message thrown when an indirect call on a block is found. + +=head1 ENVIRONMENT + +=head2 C + +If this environment variable is set to true when the pragma is used for the first time, the XS code won't be loaded and, although the C<'indirect'> lexical hint will be set to true in the scope of use, the pragma itself won't do anything. +In this case, the pragma will always be considered to be thread-safe, and as such L will be true. +This is useful for disabling C in production environments. + +Note that clearing this variable after C was loaded has no effect. +If you want to re-enable the pragma later, you also need to reload it by deleting the C<'indirect.pm'> entry from C<%INC>. + =head1 CAVEATS -C (no semicolon) at the end of a file won't be seen as an indirect object syntax, although it will as soon as there is another token before the end (as in C or C). +The implementation was tweaked to work around several limitations of vanilla C pragmas : it's thread safe, and does not suffer from a C bug that causes all pragmas to propagate into Cd scopes. + +Before C 5.12, C (no semicolon) at the end of a file is not seen as an indirect object syntax, although it is as soon as there is another token before the end (as in C or C). +If you use C 5.12 or greater, those constructs are correctly reported. With 5.8 perls, the pragma does not propagate into C. This is due to a shortcoming in the way perl handles the hints hash, which is addressed in perl 5.10. +The search for indirect method calls happens before constant folding. +Hence C will be caught. + =head1 DEPENDENCIES -L 5.8. +L 5.8.1. + +A C compiler. +This module may happen to build with a C++ compiler as well, but don't rely on it, as no guarantee is made in this regard. L (standard since perl 5.006). @@ -94,7 +244,8 @@ You can contact me by mail or on C (vincent). =head1 BUGS -Please report any bugs or feature requests to C, or through the web interface at L. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. +Please report any bugs or feature requests to C, or through the web interface at L. +I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. =head1 SUPPORT @@ -108,9 +259,11 @@ Tests code coverage report is available at L