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-rw-r--r--Master/tlpkg/tlperl/lib/pods/perldebguts.pod373
1 files changed, 247 insertions, 126 deletions
diff --git a/Master/tlpkg/tlperl/lib/pods/perldebguts.pod b/Master/tlpkg/tlperl/lib/pods/perldebguts.pod
index 402b67c242f..9bc0b63de46 100644
--- a/Master/tlpkg/tlperl/lib/pods/perldebguts.pod
+++ b/Master/tlpkg/tlperl/lib/pods/perldebguts.pod
@@ -53,7 +53,7 @@ C<"$break_condition\0$action">.
The same holds for evaluated strings that contain subroutines, or
which are currently being executed. The $filename for C<eval>ed strings
-looks like C<(eval 34)> or C<(re_eval 19)>.
+looks like C<(eval 34)> or C<(re_eval 19)>.
=item *
@@ -151,9 +151,9 @@ after the debugger completes its own initialization.)
After the rc file is read, the debugger reads the PERLDB_OPTS
environment variable and uses it to set debugger options. The
contents of this variable are treated as if they were the argument
-of an C<o ...> debugger command (q.v. in L<perldebug/Options>).
+of an C<o ...> debugger command (q.v. in L<perldebug/"Configurable Options">).
-=head3 Debugger internal variables
+=head3 Debugger Internal Variables
In addition to the file and subroutine-related variables mentioned above,
the debugger also maintains various magical internal variables.
@@ -172,7 +172,7 @@ equal to zero only if the line is not breakable.
=item *
-C<%DB::dbline>, is an alias for C<%{"::_<current_file"}>, which
+C<%DB::dbline> is an alias for C<%{"::_<current_file"}>, which
contains breakpoints and actions keyed by line number in
the currently-selected file, either explicitly chosen with the
debugger's C<f> command, or implicitly by flow of execution.
@@ -184,7 +184,7 @@ C<"$break_condition\0$action">.
=back
-=head3 Debugger customization functions
+=head3 Debugger Customization Functions
Some functions are provided to simplify customization.
@@ -257,8 +257,8 @@ with this one, once the C<o>ption C<frame=2> has been set:
By way of demonstration, we present below a laborious listing
resulting from setting your C<PERLDB_OPTS> environment variable to
the value C<f=n N>, and running I<perl -d -V> from the command line.
-Examples use various values of C<n> are shown to give you a feel
-for the difference between settings. Long those it may be, this
+Examples using various values of C<n> are shown to give you a feel
+for the difference between settings. Long though it may be, this
is not a complete listing, but only excerpts.
=over 4
@@ -397,7 +397,7 @@ When a package is compiled, a line like this
is printed with proper indentation.
-=head1 Debugging regular expressions
+=head1 Debugging Regular Expressions
There are two ways to enable debugging output for regular expressions.
@@ -408,7 +408,7 @@ Otherwise, one can C<use re 'debug'>, which has effects at
compile time and run time. Since Perl 5.9.5, this pragma is lexically
scoped.
-=head2 Compile-time output
+=head2 Compile-time Output
The debugging output at compile time looks like this:
@@ -514,7 +514,7 @@ C<(??{ code })>.
=item C<anchored(TYPE)>
-If the pattern may match only at a handful of places, (with C<TYPE>
+If the pattern may match only at a handful of places, with C<TYPE>
being C<BOL>, C<MBOL>, or C<GPOS>. See the table below.
=back
@@ -532,119 +532,240 @@ form of the regex. Each line has format
C< >I<id>: I<TYPE> I<OPTIONAL-INFO> (I<next-id>)
-=head2 Types of nodes
+=head2 Types of Nodes
Here are the possible types, with short descriptions:
- # TYPE arg-description [num-args] [longjump-len] DESCRIPTION
-
- # Exit points
- END no End of program.
- SUCCEED no Return from a subroutine, basically.
-
- # Anchors:
- BOL no Match "" at beginning of line.
- MBOL no Same, assuming multiline.
- SBOL no Same, assuming singleline.
- EOS no Match "" at end of string.
- EOL no Match "" at end of line.
- MEOL no Same, assuming multiline.
- SEOL no Same, assuming singleline.
- BOUND no Match "" at any word boundary
- BOUNDL no Match "" at any word boundary
- NBOUND no Match "" at any word non-boundary
- NBOUNDL no Match "" at any word non-boundary
- GPOS no Matches where last m//g left off.
-
- # [Special] alternatives
- ANY no Match any one character (except newline).
- SANY no Match any one character.
- ANYOF sv Match character in (or not in) this class.
- ALNUM no Match any alphanumeric character
- ALNUML no Match any alphanumeric char in locale
- NALNUM no Match any non-alphanumeric character
- NALNUML no Match any non-alphanumeric char in locale
- SPACE no Match any whitespace character
- SPACEL no Match any whitespace char in locale
- NSPACE no Match any non-whitespace character
- NSPACEL no Match any non-whitespace char in locale
- DIGIT no Match any numeric character
- NDIGIT no Match any non-numeric character
-
- # BRANCH The set of branches constituting a single choice are hooked
- # together with their "next" pointers, since precedence prevents
- # anything being concatenated to any individual branch. The
- # "next" pointer of the last BRANCH in a choice points to the
- # thing following the whole choice. This is also where the
- # final "next" pointer of each individual branch points; each
- # branch starts with the operand node of a BRANCH node.
- #
- BRANCH node Match this alternative, or the next...
-
- # BACK Normal "next" pointers all implicitly point forward; BACK
- # exists to make loop structures possible.
- # not used
- BACK no Match "", "next" ptr points backward.
-
- # Literals
- EXACT sv Match this string (preceded by length).
- EXACTF sv Match this string, folded (prec. by length).
- EXACTFL sv Match this string, folded in locale (w/len).
-
- # Do nothing
- NOTHING no Match empty string.
- # A variant of above which delimits a group, thus stops optimizations
- TAIL no Match empty string. Can jump here from outside.
-
- # STAR,PLUS '?', and complex '*' and '+', are implemented as circular
- # BRANCH structures using BACK. Simple cases (one character
- # per match) are implemented with STAR and PLUS for speed
- # and to minimize recursive plunges.
- #
- STAR node Match this (simple) thing 0 or more times.
- PLUS node Match this (simple) thing 1 or more times.
-
- CURLY sv 2 Match this simple thing {n,m} times.
- CURLYN no 2 Match next-after-this simple thing
- # {n,m} times, set parens.
- CURLYM no 2 Match this medium-complex thing {n,m} times.
- CURLYX sv 2 Match this complex thing {n,m} times.
-
- # This terminator creates a loop structure for CURLYX
- WHILEM no Do curly processing and see if rest matches.
-
- # OPEN,CLOSE,GROUPP ...are numbered at compile time.
- OPEN num 1 Mark this point in input as start of #n.
- CLOSE num 1 Analogous to OPEN.
-
- REF num 1 Match some already matched string
- REFF num 1 Match already matched string, folded
- REFFL num 1 Match already matched string, folded in loc.
-
- # grouping assertions
- IFMATCH off 1 2 Succeeds if the following matches.
- UNLESSM off 1 2 Fails if the following matches.
- SUSPEND off 1 1 "Independent" sub-regex.
- IFTHEN off 1 1 Switch, should be preceded by switcher .
- GROUPP num 1 Whether the group matched.
-
- # Support for long regex
- LONGJMP off 1 1 Jump far away.
- BRANCHJ off 1 1 BRANCH with long offset.
-
- # The heavy worker
- EVAL evl 1 Execute some Perl code.
-
- # Modifiers
- MINMOD no Next operator is not greedy.
- LOGICAL no Next opcode should set the flag only.
-
- # This is not used yet
- RENUM off 1 1 Group with independently numbered parens.
-
- # This is not really a node, but an optimized away piece of a "long" node.
- # To simplify debugging output, we mark it as if it were a node
- OPTIMIZED off Placeholder for dump.
+ # TYPE arg-description [num-args] [longjump-len] DESCRIPTION
+
+ # Exit points
+ END no End of program.
+ SUCCEED no Return from a subroutine, basically.
+
+ # Anchors:
+
+ BOL no Match "" at beginning of line.
+ MBOL no Same, assuming multiline.
+ SBOL no Same, assuming singleline.
+ EOS no Match "" at end of string.
+ EOL no Match "" at end of line.
+ MEOL no Same, assuming multiline.
+ SEOL no Same, assuming singleline.
+ BOUND no Match "" at any word boundary using native charset
+ semantics for non-utf8
+ BOUNDL no Match "" at any locale word boundary
+ BOUNDU no Match "" at any word boundary using Unicode semantics
+ BOUNDA no Match "" at any word boundary using ASCII semantics
+ NBOUND no Match "" at any word non-boundary using native charset
+ semantics for non-utf8
+ NBOUNDL no Match "" at any locale word non-boundary
+ NBOUNDU no Match "" at any word non-boundary using Unicode semantics
+ NBOUNDA no Match "" at any word non-boundary using ASCII semantics
+ GPOS no Matches where last m//g left off.
+
+ # [Special] alternatives:
+
+ REG_ANY no Match any one character (except newline).
+ SANY no Match any one character.
+ CANY no Match any one byte.
+ ANYOF sv Match character in (or not in) this class, single char
+ match only
+ ANYOFV sv Match character in (or not in) this class, can
+ match-multiple chars
+ ALNUM no Match any alphanumeric character using native charset
+ semantics for non-utf8
+ ALNUML no Match any alphanumeric char in locale
+ ALNUMU no Match any alphanumeric char using Unicode semantics
+ ALNUMA no Match [A-Za-z_0-9]
+ NALNUM no Match any non-alphanumeric character using native charset
+ semantics for non-utf8
+ NALNUML no Match any non-alphanumeric char in locale
+ NALNUMU no Match any non-alphanumeric char using Unicode semantics
+ NALNUMA no Match [^A-Za-z_0-9]
+ SPACE no Match any whitespace character using native charset
+ semantics for non-utf8
+ SPACEL no Match any whitespace char in locale
+ SPACEU no Match any whitespace char using Unicode semantics
+ SPACEA no Match [ \t\n\f\r]
+ NSPACE no Match any non-whitespace character using native charset
+ semantics for non-utf8
+ NSPACEL no Match any non-whitespace char in locale
+ NSPACEU no Match any non-whitespace char using Unicode semantics
+ NSPACEA no Match [^ \t\n\f\r]
+ DIGIT no Match any numeric character using native charset semantics
+ for non-utf8
+ DIGITL no Match any numeric character in locale
+ DIGITA no Match [0-9]
+ NDIGIT no Match any non-numeric character using native charset
+ i semantics for non-utf8
+ NDIGITL no Match any non-numeric character in locale
+ NDIGITA no Match [^0-9]
+ CLUMP no Match any extended grapheme cluster sequence
+
+ # Alternation
+
+ # BRANCH The set of branches constituting a single choice are hooked
+ # together with their "next" pointers, since precedence prevents
+ # anything being concatenated to any individual branch. The
+ # "next" pointer of the last BRANCH in a choice points to the
+ # thing following the whole choice. This is also where the
+ # final "next" pointer of each individual branch points; each
+ # branch starts with the operand node of a BRANCH node.
+ #
+ BRANCH node Match this alternative, or the next...
+
+ # Back pointer
+
+ # BACK Normal "next" pointers all implicitly point forward; BACK
+ # exists to make loop structures possible.
+ # not used
+ BACK no Match "", "next" ptr points backward.
+
+ # Literals
+
+ EXACT str Match this string (preceded by length).
+ EXACTF str Match this string, folded, native charset semantics for
+ non-utf8 (prec. by length).
+ EXACTFL str Match this string, folded in locale (w/len).
+ EXACTFU str Match this string, folded, Unicode semantics for non-utf8
+ (prec. by length).
+ EXACTFA str Match this string, folded, Unicode semantics for non-utf8,
+ but no ASCII-range character matches outside ASCII (prec.
+ by length),.
+
+ # Do nothing types
+
+ NOTHING no Match empty string.
+ # A variant of above which delimits a group, thus stops optimizations
+ TAIL no Match empty string. Can jump here from outside.
+
+ # Loops
+
+ # STAR,PLUS '?', and complex '*' and '+', are implemented as circular
+ # BRANCH structures using BACK. Simple cases (one character
+ # per match) are implemented with STAR and PLUS for speed
+ # and to minimize recursive plunges.
+ #
+ STAR node Match this (simple) thing 0 or more times.
+ PLUS node Match this (simple) thing 1 or more times.
+
+ CURLY sv 2 Match this simple thing {n,m} times.
+ CURLYN no 2 Capture next-after-this simple thing
+ CURLYM no 2 Capture this medium-complex thing {n,m} times.
+ CURLYX sv 2 Match this complex thing {n,m} times.
+
+ # This terminator creates a loop structure for CURLYX
+ WHILEM no Do curly processing and see if rest matches.
+
+ # Buffer related
+
+ # OPEN,CLOSE,GROUPP ...are numbered at compile time.
+ OPEN num 1 Mark this point in input as start of #n.
+ CLOSE num 1 Analogous to OPEN.
+
+ REF num 1 Match some already matched string
+ REFF num 1 Match already matched string, folded using native charset
+ semantics for non-utf8
+ REFFL num 1 Match already matched string, folded in loc.
+ REFFU num 1 Match already matched string, folded using unicode
+ semantics for non-utf8
+ REFFA num 1 Match already matched string, folded using unicode
+ semantics for non-utf8, no mixing ASCII, non-ASCII
+
+ # Named references. Code in regcomp.c assumes that these all are after the
+ # numbered references
+ NREF no-sv 1 Match some already matched string
+ NREFF no-sv 1 Match already matched string, folded using native charset
+ semantics for non-utf8
+ NREFFL no-sv 1 Match already matched string, folded in loc.
+ NREFFU num 1 Match already matched string, folded using unicode
+ semantics for non-utf8
+ NREFFA num 1 Match already matched string, folded using unicode
+ semantics for non-utf8, no mixing ASCII, non-ASCII
+
+ IFMATCH off 1 2 Succeeds if the following matches.
+ UNLESSM off 1 2 Fails if the following matches.
+ SUSPEND off 1 1 "Independent" sub-RE.
+ IFTHEN off 1 1 Switch, should be preceded by switcher.
+ GROUPP num 1 Whether the group matched.
+
+ # Support for long RE
+
+ LONGJMP off 1 1 Jump far away.
+ BRANCHJ off 1 1 BRANCH with long offset.
+
+ # The heavy worker
+
+ EVAL evl 1 Execute some Perl code.
+
+ # Modifiers
+
+ MINMOD no Next operator is not greedy.
+ LOGICAL no Next opcode should set the flag only.
+
+ # This is not used yet
+ RENUM off 1 1 Group with independently numbered parens.
+
+ # Trie Related
+
+ # Behave the same as A|LIST|OF|WORDS would. The '..C' variants have
+ # inline charclass data (ascii only), the 'C' store it in the structure.
+ # NOTE: the relative order of the TRIE-like regops is significant
+
+ TRIE trie 1 Match many EXACT(F[ALU]?)? at once. flags==type
+ TRIEC charclass Same as TRIE, but with embedded charclass data
+
+ # For start classes, contains an added fail table.
+ AHOCORASICK trie 1 Aho Corasick stclass. flags==type
+ AHOCORASICKC charclass Same as AHOCORASICK, but with embedded charclass data
+
+ # Regex Subroutines
+ GOSUB num/ofs 2L recurse to paren arg1 at (signed) ofs arg2
+ GOSTART no recurse to start of pattern
+
+ # Special conditionals
+ NGROUPP no-sv 1 Whether the group matched.
+ INSUBP num 1 Whether we are in a specific recurse.
+ DEFINEP none 1 Never execute directly.
+
+ # Backtracking Verbs
+ ENDLIKE none Used only for the type field of verbs
+ OPFAIL none Same as (?!)
+ ACCEPT parno 1 Accepts the current matched string.
+
+
+ # Verbs With Arguments
+ VERB no-sv 1 Used only for the type field of verbs
+ PRUNE no-sv 1 Pattern fails at this startpoint if no-backtracking through this
+ MARKPOINT no-sv 1 Push the current location for rollback by cut.
+ SKIP no-sv 1 On failure skip forward (to the mark) before retrying
+ COMMIT no-sv 1 Pattern fails outright if backtracking through this
+ CUTGROUP no-sv 1 On failure go to the next alternation in the group
+
+ # Control what to keep in $&.
+ KEEPS no $& begins here.
+
+ # New charclass like patterns
+ LNBREAK none generic newline pattern
+ VERTWS none vertical whitespace (Perl 6)
+ NVERTWS none not vertical whitespace (Perl 6)
+ HORIZWS none horizontal whitespace (Perl 6)
+ NHORIZWS none not horizontal whitespace (Perl 6)
+
+ FOLDCHAR codepoint 1 codepoint with tricky case folding properties.
+
+ # SPECIAL REGOPS
+
+ # This is not really a node, but an optimized away piece of a "long" node.
+ # To simplify debugging output, we mark it as if it were a node
+ OPTIMIZED off Placeholder for dump.
+
+ # Special opcode with the property that no opcode in a compiled program
+ # will ever be of this type. Thus it can be used as a flag value that
+ # no other opcode has been seen. END is used similarly, in that an END
+ # node cant be optimized. So END implies "unoptimizable" and PSEUDO mean
+ # "not seen anything to optimize yet".
+ PSEUDO off Pseudo opcode for internal use.
=for unprinted-credits
Next section M-J. Dominus (mjd-perl-patch+@plover.com) 20010421
@@ -676,7 +797,7 @@ is, it corresponds to the C<+> symbol in the precompiled regex.
C<0[0]> items indicate that there is no corresponding node.
-=head2 Run-time output
+=head2 Run-time Output
First of all, when doing a match, one may get no run-time output even
if debugging is enabled. This means that the regex engine was never
@@ -719,7 +840,7 @@ C< >I<STRING-OFFSET> <I<PRE-STRING>> <I<POST-STRING>> |I<ID>: I<TYPE>
The I<TYPE> info is indented with respect to the backtracking level.
Other incidental information appears interspersed within.
-=head1 Debugging Perl memory usage
+=head1 Debugging Perl Memory Usage
Perl is a profligate wastrel when it comes to memory use. There
is a saying that to estimate memory usage of Perl, assume a reasonable
@@ -755,7 +876,7 @@ The B<-DL> command-line switch is obsolete since circa Perl 5.6.0
The switch was used to track Perl's memory allocations and possible
memory leaks. These days the use of malloc debugging tools like
F<Purify> or F<valgrind> is suggested instead. See also
-L<perlhack/PERL_MEM_LOG>.
+L<perlhacktips/PERL_MEM_LOG>.
One way to find out how much memory is being used by Perl data
structures is to install the Devel::Size module from CPAN: it gives
@@ -764,7 +885,7 @@ structure. Please be mindful of the difference between the size()
and total_size().
If Perl has been compiled using Perl's malloc you can analyze Perl
-memory usage by setting the $ENV{PERL_DEBUG_MSTATS}.
+memory usage by setting $ENV{PERL_DEBUG_MSTATS}.
=head2 Using C<$ENV{PERL_DEBUG_MSTATS}>
@@ -812,7 +933,7 @@ would have usable size 8188, and the memory footprint would be 8192.
In a Perl built for debugging, some buckets may have negative usable
size. This means that these buckets cannot (and will not) be used.
For larger buckets, the memory footprint may be one page greater
-than a power of 2. If so, case the corresponding power of two is
+than a power of 2. If so, the corresponding power of two is
printed in the C<APPROX> field above.
=item Free/Used
@@ -830,7 +951,7 @@ were
free: 8 16 32 64 128 256 512 1024 2048 4096 8192
4 12 24 48 80
-With non-C<DEBUGGING> perl, the buckets starting from C<128> have
+With a non-C<DEBUGGING> perl, the buckets starting from C<128> have
a 4-byte overhead, and thus an 8192-long bucket may take up to
8188-byte allocations.