From 844c971d8aeb2693bc01739963f5da675b989d03 Mon Sep 17 00:00:00 2001 From: Kirill Volinsky Date: Sat, 2 Aug 2014 14:17:32 +0000 Subject: added pcre16 project git-svn-id: http://svn.miranda-ng.org/main/trunk@10019 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c --- plugins/Pcre16/docs/doc/html/pcrebuild.html | 534 ++++++++++++++++++++++++++++ 1 file changed, 534 insertions(+) create mode 100644 plugins/Pcre16/docs/doc/html/pcrebuild.html (limited to 'plugins/Pcre16/docs/doc/html/pcrebuild.html') diff --git a/plugins/Pcre16/docs/doc/html/pcrebuild.html b/plugins/Pcre16/docs/doc/html/pcrebuild.html new file mode 100644 index 0000000000..03c8cbe0b2 --- /dev/null +++ b/plugins/Pcre16/docs/doc/html/pcrebuild.html @@ -0,0 +1,534 @@ + + +pcrebuild specification + + +

pcrebuild man page

+

+Return to the PCRE index page. +

+

+This page is part of the PCRE HTML documentation. It was generated automatically +from the original man page. If there is any nonsense in it, please consult the +man page, in case the conversion went wrong. +
+

+
BUILDING PCRE
+

+PCRE is distributed with a configure script that can be used to build the +library in Unix-like environments using the applications known as Autotools. +Also in the distribution are files to support building using CMake +instead of configure. The text file +README +contains general information about building with Autotools (some of which is +repeated below), and also has some comments about building on various operating +systems. There is a lot more information about building PCRE without using +Autotools (including information about using CMake and building "by +hand") in the text file called +NON-AUTOTOOLS-BUILD. +You should consult this file as well as the +README +file if you are building in a non-Unix-like environment. +

+
PCRE BUILD-TIME OPTIONS
+

+The rest of this document describes the optional features of PCRE that can be +selected when the library is compiled. It assumes use of the configure +script, where the optional features are selected or deselected by providing +options to configure before running the make command. However, the +same options can be selected in both Unix-like and non-Unix-like environments +using the GUI facility of cmake-gui if you are using CMake instead +of configure to build PCRE. +

+

+If you are not using Autotools or CMake, option selection can be done by +editing the config.h file, or by passing parameter settings to the +compiler, as described in +NON-AUTOTOOLS-BUILD. +

+

+The complete list of options for configure (which includes the standard +ones such as the selection of the installation directory) can be obtained by +running +

+  ./configure --help
+
+The following sections include descriptions of options whose names begin with +--enable or --disable. These settings specify changes to the defaults for the +configure command. Because of the way that configure works, +--enable and --disable always come in pairs, so the complementary option always +exists as well, but as it specifies the default, it is not described. +

+
BUILDING 8-BIT, 16-BIT AND 32-BIT LIBRARIES
+

+By default, a library called libpcre is built, containing functions that +take string arguments contained in vectors of bytes, either as single-byte +characters, or interpreted as UTF-8 strings. You can also build a separate +library, called libpcre16, in which strings are contained in vectors of +16-bit data units and interpreted either as single-unit characters or UTF-16 +strings, by adding +

+  --enable-pcre16
+
+to the configure command. You can also build yet another separate +library, called libpcre32, in which strings are contained in vectors of +32-bit data units and interpreted either as single-unit characters or UTF-32 +strings, by adding +
+  --enable-pcre32
+
+to the configure command. If you do not want the 8-bit library, add +
+  --disable-pcre8
+
+as well. At least one of the three libraries must be built. Note that the C++ +and POSIX wrappers are for the 8-bit library only, and that pcregrep is +an 8-bit program. None of these are built if you select only the 16-bit or +32-bit libraries. +

+
BUILDING SHARED AND STATIC LIBRARIES
+

+The Autotools PCRE building process uses libtool to build both shared and +static libraries by default. You can suppress one of these by adding one of +

+  --disable-shared
+  --disable-static
+
+to the configure command, as required. +

+
C++ SUPPORT
+

+By default, if the 8-bit library is being built, the configure script +will search for a C++ compiler and C++ header files. If it finds them, it +automatically builds the C++ wrapper library (which supports only 8-bit +strings). You can disable this by adding +

+  --disable-cpp
+
+to the configure command. +

+
UTF-8, UTF-16 AND UTF-32 SUPPORT
+

+To build PCRE with support for UTF Unicode character strings, add +

+  --enable-utf
+
+to the configure command. This setting applies to all three libraries, +adding support for UTF-8 to the 8-bit library, support for UTF-16 to the 16-bit +library, and support for UTF-32 to the to the 32-bit library. There are no +separate options for enabling UTF-8, UTF-16 and UTF-32 independently because +that would allow ridiculous settings such as requesting UTF-16 support while +building only the 8-bit library. It is not possible to build one library with +UTF support and another without in the same configuration. (For backwards +compatibility, --enable-utf8 is a synonym of --enable-utf.) +

+

+Of itself, this setting does not make PCRE treat strings as UTF-8, UTF-16 or +UTF-32. As well as compiling PCRE with this option, you also have have to set +the PCRE_UTF8, PCRE_UTF16 or PCRE_UTF32 option (as appropriate) when you call +one of the pattern compiling functions. +

+

+If you set --enable-utf when compiling in an EBCDIC environment, PCRE expects +its input to be either ASCII or UTF-8 (depending on the run-time option). It is +not possible to support both EBCDIC and UTF-8 codes in the same version of the +library. Consequently, --enable-utf and --enable-ebcdic are mutually +exclusive. +

+
UNICODE CHARACTER PROPERTY SUPPORT
+

+UTF support allows the libraries to process character codepoints up to 0x10ffff +in the strings that they handle. On its own, however, it does not provide any +facilities for accessing the properties of such characters. If you want to be +able to use the pattern escapes \P, \p, and \X, which refer to Unicode +character properties, you must add +

+  --enable-unicode-properties
+
+to the configure command. This implies UTF support, even if you have +not explicitly requested it. +

+

+Including Unicode property support adds around 30K of tables to the PCRE +library. Only the general category properties such as Lu and Nd are +supported. Details are given in the +pcrepattern +documentation. +

+
JUST-IN-TIME COMPILER SUPPORT
+

+Just-in-time compiler support is included in the build by specifying +

+  --enable-jit
+
+This support is available only for certain hardware architectures. If this +option is set for an unsupported architecture, a compile time error occurs. +See the +pcrejit +documentation for a discussion of JIT usage. When JIT support is enabled, +pcregrep automatically makes use of it, unless you add +
+  --disable-pcregrep-jit
+
+to the "configure" command. +

+
CODE VALUE OF NEWLINE
+

+By default, PCRE interprets the linefeed (LF) character as indicating the end +of a line. This is the normal newline character on Unix-like systems. You can +compile PCRE to use carriage return (CR) instead, by adding +

+  --enable-newline-is-cr
+
+to the configure command. There is also a --enable-newline-is-lf option, +which explicitly specifies linefeed as the newline character. +
+
+Alternatively, you can specify that line endings are to be indicated by the two +character sequence CRLF. If you want this, add +
+  --enable-newline-is-crlf
+
+to the configure command. There is a fourth option, specified by +
+  --enable-newline-is-anycrlf
+
+which causes PCRE to recognize any of the three sequences CR, LF, or CRLF as +indicating a line ending. Finally, a fifth option, specified by +
+  --enable-newline-is-any
+
+causes PCRE to recognize any Unicode newline sequence. +

+

+Whatever line ending convention is selected when PCRE is built can be +overridden when the library functions are called. At build time it is +conventional to use the standard for your operating system. +

+
WHAT \R MATCHES
+

+By default, the sequence \R in a pattern matches any Unicode newline sequence, +whatever has been selected as the line ending sequence. If you specify +

+  --enable-bsr-anycrlf
+
+the default is changed so that \R matches only CR, LF, or CRLF. Whatever is +selected when PCRE is built can be overridden when the library functions are +called. +

+
POSIX MALLOC USAGE
+

+When the 8-bit library is called through the POSIX interface (see the +pcreposix +documentation), additional working storage is required for holding the pointers +to capturing substrings, because PCRE requires three integers per substring, +whereas the POSIX interface provides only two. If the number of expected +substrings is small, the wrapper function uses space on the stack, because this +is faster than using malloc() for each call. The default threshold above +which the stack is no longer used is 10; it can be changed by adding a setting +such as +

+  --with-posix-malloc-threshold=20
+
+to the configure command. +

+
HANDLING VERY LARGE PATTERNS
+

+Within a compiled pattern, offset values are used to point from one part to +another (for example, from an opening parenthesis to an alternation +metacharacter). By default, in the 8-bit and 16-bit libraries, two-byte values +are used for these offsets, leading to a maximum size for a compiled pattern of +around 64K. This is sufficient to handle all but the most gigantic patterns. +Nevertheless, some people do want to process truly enormous patterns, so it is +possible to compile PCRE to use three-byte or four-byte offsets by adding a +setting such as +

+  --with-link-size=3
+
+to the configure command. The value given must be 2, 3, or 4. For the +16-bit library, a value of 3 is rounded up to 4. In these libraries, using +longer offsets slows down the operation of PCRE because it has to load +additional data when handling them. For the 32-bit library the value is always +4 and cannot be overridden; the value of --with-link-size is ignored. +

+
AVOIDING EXCESSIVE STACK USAGE
+

+When matching with the pcre_exec() function, PCRE implements backtracking +by making recursive calls to an internal function called match(). In +environments where the size of the stack is limited, this can severely limit +PCRE's operation. (The Unix environment does not usually suffer from this +problem, but it may sometimes be necessary to increase the maximum stack size. +There is a discussion in the +pcrestack +documentation.) An alternative approach to recursion that uses memory from the +heap to remember data, instead of using recursive function calls, has been +implemented to work round the problem of limited stack size. If you want to +build a version of PCRE that works this way, add +

+  --disable-stack-for-recursion
+
+to the configure command. With this configuration, PCRE will use the +pcre_stack_malloc and pcre_stack_free variables to call memory +management functions. By default these point to malloc() and +free(), but you can replace the pointers so that your own functions are +used instead. +

+

+Separate functions are provided rather than using pcre_malloc and +pcre_free because the usage is very predictable: the block sizes +requested are always the same, and the blocks are always freed in reverse +order. A calling program might be able to implement optimized functions that +perform better than malloc() and free(). PCRE runs noticeably more +slowly when built in this way. This option affects only the pcre_exec() +function; it is not relevant for pcre_dfa_exec(). +

+
LIMITING PCRE RESOURCE USAGE
+

+Internally, PCRE has a function called match(), which it calls repeatedly +(sometimes recursively) when matching a pattern with the pcre_exec() +function. By controlling the maximum number of times this function may be +called during a single matching operation, a limit can be placed on the +resources used by a single call to pcre_exec(). The limit can be changed +at run time, as described in the +pcreapi +documentation. The default is 10 million, but this can be changed by adding a +setting such as +

+  --with-match-limit=500000
+
+to the configure command. This setting has no effect on the +pcre_dfa_exec() matching function. +

+

+In some environments it is desirable to limit the depth of recursive calls of +match() more strictly than the total number of calls, in order to +restrict the maximum amount of stack (or heap, if --disable-stack-for-recursion +is specified) that is used. A second limit controls this; it defaults to the +value that is set for --with-match-limit, which imposes no additional +constraints. However, you can set a lower limit by adding, for example, +

+  --with-match-limit-recursion=10000
+
+to the configure command. This value can also be overridden at run time. +

+
CREATING CHARACTER TABLES AT BUILD TIME
+

+PCRE uses fixed tables for processing characters whose code values are less +than 256. By default, PCRE is built with a set of tables that are distributed +in the file pcre_chartables.c.dist. These tables are for ASCII codes +only. If you add +

+  --enable-rebuild-chartables
+
+to the configure command, the distributed tables are no longer used. +Instead, a program called dftables is compiled and run. This outputs the +source for new set of tables, created in the default locale of your C run-time +system. (This method of replacing the tables does not work if you are cross +compiling, because dftables is run on the local host. If you need to +create alternative tables when cross compiling, you will have to do so "by +hand".) +

+
USING EBCDIC CODE
+

+PCRE assumes by default that it will run in an environment where the character +code is ASCII (or Unicode, which is a superset of ASCII). This is the case for +most computer operating systems. PCRE can, however, be compiled to run in an +EBCDIC environment by adding +

+  --enable-ebcdic
+
+to the configure command. This setting implies +--enable-rebuild-chartables. You should only use it if you know that you are in +an EBCDIC environment (for example, an IBM mainframe operating system). The +--enable-ebcdic option is incompatible with --enable-utf. +

+

+The EBCDIC character that corresponds to an ASCII LF is assumed to have the +value 0x15 by default. However, in some EBCDIC environments, 0x25 is used. In +such an environment you should use +

+  --enable-ebcdic-nl25
+
+as well as, or instead of, --enable-ebcdic. The EBCDIC character for CR has the +same value as in ASCII, namely, 0x0d. Whichever of 0x15 and 0x25 is not +chosen as LF is made to correspond to the Unicode NEL character (which, in +Unicode, is 0x85). +

+

+The options that select newline behaviour, such as --enable-newline-is-cr, +and equivalent run-time options, refer to these character values in an EBCDIC +environment. +

+
PCREGREP OPTIONS FOR COMPRESSED FILE SUPPORT
+

+By default, pcregrep reads all files as plain text. You can build it so +that it recognizes files whose names end in .gz or .bz2, and reads +them with libz or libbz2, respectively, by adding one or both of +

+  --enable-pcregrep-libz
+  --enable-pcregrep-libbz2
+
+to the configure command. These options naturally require that the +relevant libraries are installed on your system. Configuration will fail if +they are not. +

+
PCREGREP BUFFER SIZE
+

+pcregrep uses an internal buffer to hold a "window" on the file it is +scanning, in order to be able to output "before" and "after" lines when it +finds a match. The size of the buffer is controlled by a parameter whose +default value is 20K. The buffer itself is three times this size, but because +of the way it is used for holding "before" lines, the longest line that is +guaranteed to be processable is the parameter size. You can change the default +parameter value by adding, for example, +

+  --with-pcregrep-bufsize=50K
+
+to the configure command. The caller of \fPpcregrep\fP can, however, +override this value by specifying a run-time option. +

+
PCRETEST OPTION FOR LIBREADLINE SUPPORT
+

+If you add +

+  --enable-pcretest-libreadline
+
+to the configure command, pcretest is linked with the +libreadline library, and when its input is from a terminal, it reads it +using the readline() function. This provides line-editing and history +facilities. Note that libreadline is GPL-licensed, so if you distribute a +binary of pcretest linked in this way, there may be licensing issues. +

+

+Setting this option causes the -lreadline option to be added to the +pcretest build. In many operating environments with a sytem-installed +libreadline this is sufficient. However, in some environments (e.g. +if an unmodified distribution version of readline is in use), some extra +configuration may be necessary. The INSTALL file for libreadline says +this: +

+  "Readline uses the termcap functions, but does not link with the
+  termcap or curses library itself, allowing applications which link
+  with readline the to choose an appropriate library."
+
+If your environment has not been set up so that an appropriate library is +automatically included, you may need to add something like +
+  LIBS="-ncurses"
+
+immediately before the configure command. +

+
DEBUGGING WITH VALGRIND SUPPORT
+

+By adding the +

+  --enable-valgrind
+
+option to to the configure command, PCRE will use valgrind annotations +to mark certain memory regions as unaddressable. This allows it to detect +invalid memory accesses, and is mostly useful for debugging PCRE itself. +

+
CODE COVERAGE REPORTING
+

+If your C compiler is gcc, you can build a version of PCRE that can generate a +code coverage report for its test suite. To enable this, you must install +lcov version 1.6 or above. Then specify +

+  --enable-coverage
+
+to the configure command and build PCRE in the usual way. +

+

+Note that using ccache (a caching C compiler) is incompatible with code +coverage reporting. If you have configured ccache to run automatically +on your system, you must set the environment variable +

+  CCACHE_DISABLE=1
+
+before running make to build PCRE, so that ccache is not used. +

+

+When --enable-coverage is used, the following addition targets are added to the +Makefile: +

+  make coverage
+
+This creates a fresh coverage report for the PCRE test suite. It is equivalent +to running "make coverage-reset", "make coverage-baseline", "make check", and +then "make coverage-report". +
+  make coverage-reset
+
+This zeroes the coverage counters, but does nothing else. +
+  make coverage-baseline
+
+This captures baseline coverage information. +
+  make coverage-report
+
+This creates the coverage report. +
+  make coverage-clean-report
+
+This removes the generated coverage report without cleaning the coverage data +itself. +
+  make coverage-clean-data
+
+This removes the captured coverage data without removing the coverage files +created at compile time (*.gcno). +
+  make coverage-clean
+
+This cleans all coverage data including the generated coverage report. For more +information about code coverage, see the gcov and lcov +documentation. +

+
SEE ALSO
+

+pcreapi(3), pcre16, pcre32, pcre_config(3). +

+
AUTHOR
+

+Philip Hazel +
+University Computing Service +
+Cambridge CB2 3QH, England. +
+

+
REVISION
+

+Last updated: 12 May 2013 +
+Copyright © 1997-2013 University of Cambridge. +
+

+Return to the PCRE index page. +

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