PCRE for use with Hercules

This repository contains an unmodified copy of PCRE 8.41, retrieved October 2017 from http://www.pcre.org/ and stored in the pkg\_src subdirectory. This should allow a complete replacement of the pkg\_src directory contents when an uplevel upstream PCRE distribution becomes available.

A substantially modified CMake build script has been added. The CMake script, while based on the original CMakeLists.txt script in the upstream PCRE distribution, is specific to Hercules' requirements and only builds the pcre and pcreposix shared libraries and only does so for Windows target systems. The build script exports targets for the build directory, and for the installation directory if the pcre and pcreposix shared libraries are installed. The CMake build for Hercules can import either target. If PCRE is built by the CMake build for Hercules, the build directory target is used.

The CMake build for Hercules will clone and build this repository if PCRE is not installed on the target system. This is the likely case, as PCRE or its equivalent functionality is not part of Microsoft Windows.

Build scripts and other programming in the top level is copyright by Stephen Orso and is licensed under the same BSD license as is used for the original PCRE distribution. Documentation and other writing is licensed using the Creative Commons By-SA 4.0 license.

Each file contains specific copyright and license information.

The PCRE package retains its original copyright and license, which can be found at pkg_src/LICENCE.

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CMake -D Configuration Option Variables

Except for BUILD_TESTING, the configuration options used by the CMake build for Hercules ensure that the PCRE library is built in a manner consistent with the options and target for which Hercules is being built.

• PCRE_BUILD_TESTS ON | OFF, default is OFF When ON, include the pcretest executable in the build tree and generate test cases to verify the operation of PCRE
• DEBUG ON | OFF, default is OFF Applicable to single-configuration generators like Nmake. When ON, generate a Debug configuration build script. When OFF, generate a Release script. The configuration used for Microsoft Visual Studio, a multi-configuration generator, is determined at build time.)
• WINTARGET blank | HOST | DIST | windows-version Applicable when building on Windows. Option windows-version may be any of WinXP364, WinVista, Win7, Win8, Win10 and is case insensitive. When blank or HOST, build for the version of Windows on the host. When DIST, build for the earliest version of Windows supported by Hercules, Windows XP SP3 64-bit. Otherwise build for the Windows version specified.

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CMakeLists.txt Functional Differences

Functional changes made to the PCRE CMakeLists.txt provided in the base PCRE distribution:

• Removed lookups to packages that are not required for Hercules' use PCRE (BZip2, Editline, Readline, and Zlib), and removed tests for C++ headers that are not required.
• Removed tests for headers and functions that were only required for pcregrep or the C++ wrapper.
• Removed all references to the 16- and 32-bit versions of PCRE.
  Hercules requires the POSIX wrapper and that wrapper only supports the 8-bit character version of PCRE.
• Removed JIT compiler support. JIT support is not available using the POSIX wrapper, and Hercules only uses the POSIX wrapper.
• Changed option defaults to build only an 8-bit PCRE shared library. The POSIX wrapper only supports 8-bit PCRE.

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Testing-related changes to CMakeLists.txt

• If PCRE_BUILD_TESTS is ON, the pcretest program compiled. It is compiled without readline() support, as Windows does not have a native readline() function.
• Executable pcretest is linked with a 16mb stack. Test 2 requires at least 8mb of stack according to test script comments. This large stack affects only the pcretest executable and does not impact the resources required by the shared library.
• Only tests 1, 2, 3, 8, 13, and 14 are run when running pcretest. The other tests involve functionality not included in this build (16, 32-bit characters, JIT, Unicode, or UTF-8).
• NOTE: in the Windows command files that run the tests, comments state tha pcregrep is needed to run the tests. This does not seem to be true, at least for tests of just 8-bit character sets, and pcregrep is not built.

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Other changes to CMakeLists.txt

• Removed support for building static libraries or linking with the static Microsoft C runtime library.
• Changed all references to source files to reflect their movement to the pkg-src directory.
• Exported both targets of the installation tree in a single target import script in the pcre-targets sub-directory.
• Exported the target of the build tree to allow for a build that references the build directory.
• Copied public Headers to the build tree include subdirectory so that the exported build tree target does not make any references to the source tree.
• Removed configuration options MinSizeRel and RelWithDebInfo if they are present in CMAKE_CONFIGURATION_TYPES.
• Replaced references to the LOCATION property in get_target_properties with generator expressions to remove a requirement for policy CMP0026.
• Miscelaneous removals: MinGW/Cygwin support, UNIX-like target systems.

CMake 3.4 is the minimum version required to build PCRE from this repository because it is the same minimum version required for Hercules.

 

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This README.md file Copyright © 2017 by Stephen R. Orso.

This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.

To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.