1--- 2layout: default 3title: ICU4C Readme 4nav_order: 8 5parent: ICU 6--- 7<!-- 8© 2020 and later: Unicode, Inc. and others. 9License & terms of use: http://www.unicode.org/copyright.html 10--> 11 12# ICU4C Readme 13{: .no_toc } 14 15## Contents 16{: .no_toc .text-delta } 17 181. TOC 19{:toc} 20 21--- 22 23 24## Introduction 25 26Today's software market is a global one in which it is desirable to develop and maintain one application (single source/single binary) that supports a wide variety of languages. The International Components for Unicode (ICU) libraries provide robust and full-featured Unicode services on a wide variety of platforms to help this design goal. The ICU libraries provide support for: 27 28* The latest version of the Unicode standard 29* Character set conversions with support for over 220 codepages 30* Locale data for more than 300 locales 31* Language sensitive text collation (sorting) and searching based on the Unicode Collation Algorithm (=ISO 14651) 32* Regular expression matching and Unicode sets 33* Transformations for normalization, upper/lowercase, script transliterations (50+ pairs) 34* Resource bundles for storing and accessing localized information 35* Date/Number/Message formatting and parsing of culture specific input/output formats 36* Calendar specific date and time manipulation 37* Text boundary analysis for finding characters, word and sentence boundaries 38 39ICU has a sister project ICU4J that extends the internationalization capabilities of Java to a level similar to ICU. The ICU C/C++ project is also called ICU4C when a distinction is necessary. 40 41## Getting started 42 43This document describes how to build and install ICU on your machine. For other information about ICU please see the following table of links. 44The ICU homepage also links to related information about writing internationalized software. 45 46**Here are some useful links regarding ICU and internationalization in general.** 47 48 49| ICU, ICU4C & ICU4J Homepage | <http://icu-project.org/> | 50| FAQ - Frequently Asked Questions about ICU | <https://unicode-org.github.io/icu/userguide/icufaq/> | 51| ICU User's Guide | <https://unicode-org.github.io/icu/> | 52| How To Use ICU | <https://unicode-org.github.io/icu/userguide/howtouseicu.html> | 53| Download ICU Releases | <http://site.icu-project.org/download> | 54| ICU4C API Documentation Online | <http://icu-project.org/apiref/icu4c/> | 55| Online ICU Demos | <http://demo.icu-project.org/icu-bin/icudemos> | 56| Contacts and Bug Reports/Feature Requests | <http://site.icu-project.org/contacts> | 57 58**Important:** Please make sure you understand the [Copyright and License Information](http://source.icu-project.org/repos/icu/trunk/icu4c/LICENSE). 59 60## What Is New In The Current Release? 61 62See the [ICU download page](http://site.icu-project.org/download/) to find the subpage for the current release, including any other changes, bug fixes, known issues, changes to supported platforms and build environments, and migration issues for existing applications migrating from previous ICU releases. 63 64The subpage for the current release will also include an API Change Report, both for ICU4C and ICU4J, for a complete list of APIs added, removed, or changed in this release. 65 66The list of API changes since the previous ICU4C release is available [here](https://htmlpreview.github.io/?https://raw.githubusercontent.com/unicode-org/icu/master/icu4c/APIChangeReport.html). 67 68Changes in previous releases can also be found on the main [ICU download page](http://site.icu-project.org/download) in its version-specific subpages. 69 70## How To Download the Source Code 71 72There are two ways to download ICU releases: 73 74* **Official Release Snapshot:** 75 If you want to use ICU (as opposed to developing it), you should download an official packaged version of the ICU source code. These versions are tested more thoroughly than day-to-day development builds of the system, and they are packaged in zip and tar files for convenient download. These packaged files can be found at [http://site.icu-project.org/download](http://site.icu-project.org/download). 76 The packaged snapshots are named `icu-nnnn.zip` or `icu-nnnn.tgz`, where `nnnn` is the version number. The .zip file is used for Windows platforms, while the .tgz file is preferred on most other platforms. 77 Please unzip this file. 78 > :point_right: **Note**: There may be additional commits on the `maint-*` branch for a particular version that are not included in the prepackaged download files. 79* **GitHub Source Repository:** 80 If you are interested in developing features, patches, or bug fixes for ICU, you should probably be working with the latest version of the ICU source code. You will need to clone and checkout the code from our GitHub repository to ensure that you have the most recent version of all of the files. See our [source repository](http://site.icu-project.org/repository) for details. 81 82## ICU Source Code Organization 83 84In the descriptions below, `<ICU>` is the full path name of the ICU directory (the top level directory from the distribution archives) in your file system. You can also view the [ICU Architectural Design](design.md) section of the User's Guide to see which libraries you need for your software product. You need at least the data (`[lib]icudt`) and the common (`[lib]icuuc`) libraries in order to use ICU. 85 86**The following files describe the code drop.** 87 88| File | Description | 89|-------------|----------------------------------------------------------------| 90| readme.html | Describes the International Components for Unicode (this file) | 91| LICENSE | Contains the text of the ICU license | 92 93**The following directories contain source code and data files.** 94 95<table> 96 97 <tr> 98 <th scope="col">Directory</th> 99 100 <th scope="col">Description</th> 101 </tr> 102 103 <tr> 104 <td><i><ICU></i>/source/<b>common</b>/</td> 105 106 <td>The core Unicode and support functionality, such as resource bundles, 107 character properties, locales, codepage conversion, normalization, 108 Unicode properties, Locale, and UnicodeString.</td> 109 </tr> 110 111 <tr> 112 <td><i><ICU></i>/source/<b>i18n</b>/</td> 113 114 <td>Modules in i18n are generally the more data-driven, that is to say 115 resource bundle driven, components. These deal with higher-level 116 internationalization issues such as formatting, collation, text break 117 analysis, and transliteration.</td> 118 </tr> 119 120 <tr> 121 <td><i><ICU></i>/source/<b>layoutex</b>/</td> 122 123 <td>Contains the ICU paragraph layout engine.</td> 124 </tr> 125 126 <tr> 127 <td><i><ICU></i>/source/<b>io</b>/</td> 128 129 <td>Contains the ICU I/O library.</td> 130 </tr> 131 132 <tr> 133 <td><i><ICU></i>/source/<b>data</b>/</td> 134 135 <td> 136 <p>This directory contains the source data in text format, which is 137 compiled into binary form during the ICU build process. It contains 138 several subdirectories, in which the data files are grouped by 139 function. Note that the build process must be run again after any 140 changes are made to this directory.</p> 141 142 <p>If some of the following directories are missing, it's probably 143 because you got an official download. If you need the data source files 144 for customization, then please download the complete ICU source code from <a 145 href="http://site.icu-project.org/repository">the ICU repository</a>.</p> 146 147 <ul> 148 <li><b>in/</b> A directory that contains a pre-built data library for 149 ICU. A standard source code package will contain this file without 150 several of the following directories. This is to simplify the build 151 process for the majority of users and to reduce platform porting 152 issues.</li> 153 154 <li><b>brkitr/</b> Data files for character, word, sentence, title 155 casing and line boundary analysis.</li> 156 157 <li><b>coll/</b> Data for collation tailorings. The makefile 158 <b>colfiles.mk</b> contains the list of resource bundle files.</li> 159 160 <li><b>locales/</b> These .txt files contain ICU language and 161 culture-specific localization data. Two special bundles are 162 <b>root</b>, which is the fallback data and parent of other bundles, 163 and <b>index</b>, which contains a list of installed bundles. The 164 makefile <b>resfiles.mk</b> contains the list of resource bundle 165 files. Some of the locale data is split out into the type-specific 166 directories curr, lang, region, unit, and zone, described below.</li> 167 168 <li><b>curr/</b> Locale data for currency symbols and names (including 169 plural forms), with its own makefile <b>resfiles.mk</b>.</li> 170 171 <li><b>lang/</b> Locale data for names of languages, scripts, and locale 172 key names and values, with its own makefile <b>resfiles.mk</b>.</li> 173 174 <li><b>region/</b> Locale data for names of regions, with its own 175 makefile <b>resfiles.mk</b>.</li> 176 177 <li><b>unit/</b> Locale data for measurement unit patterns and names, 178 with its own makefile <b>resfiles.mk</b>.</li> 179 180 <li><b>zone/</b> Locale data for time zone names, with its own 181 makefile <b>resfiles.mk</b>.</li> 182 183 <li><b>mappings/</b> Here are the code page converter tables. These 184 .ucm files contain mappings to and from Unicode. These are compiled 185 into .cnv files. <b>convrtrs.txt</b> is the alias mapping table from 186 various converter name formats to ICU internal format and vice versa. 187 It produces cnvalias.icu. The makefiles <b>ucmfiles.mk, 188 ucmcore.mk,</b> and <b>ucmebcdic.mk</b> contain the list of 189 converters to be built.</li> 190 191 <li><b>translit/</b> This directory contains transliterator rules as 192 resource bundles, a makefile <b>trnsfiles.mk</b> containing the list 193 of installed system translitaration files, and as well the special 194 bundle <b>translit_index</b> which lists the system transliterator 195 aliases.</li> 196 197 <li><b>unidata/</b> This directory contains the Unicode data files. 198 Please see <a href= 199 "http://www.unicode.org/">http://www.unicode.org/</a> for more 200 information.</li> 201 202 <li><b>misc/</b> The misc directory contains other data files which 203 did not fit into the above categories, including time zone 204 information, region-specific data, and other data derived from CLDR 205 supplemental data.</li> 206 207 <li><b>out/</b> This directory contains the assembled memory mapped 208 files.</li> 209 210 <li><b>out/build/</b> This directory contains intermediate (compiled) 211 files, such as .cnv, .res, etc.</li> 212 </ul> 213 214 <p>If you are creating a special ICU build, you can set the ICU_DATA 215 environment variable to the out/ or the out/build/ directories, but 216 this is generally discouraged because most people set it incorrectly. 217 You can view the <a href= 218 "https://unicode-org.github.io/icu/userguide/icudata">ICU Data 219 Management</a> section of the ICU User's Guide for details.</p> 220 </td> 221 </tr> 222 223 <tr> 224 <td><i><ICU></i>/source/test/<b>intltest</b>/</td> 225 226 <td>A test suite including all C++ APIs. For information about running 227 the test suite, see the build instructions specific to your platform 228 later in this document.</td> 229 </tr> 230 231 <tr> 232 <td><i><ICU></i>/source/test/<b>cintltst</b>/</td> 233 234 <td>A test suite written in C, including all C APIs. For information 235 about running the test suite, see the build instructions specific to your 236 platform later in this document.</td> 237 </tr> 238 239 <tr> 240 <td><i><ICU></i>/source/test/<b>iotest</b>/</td> 241 242 <td>A test suite written in C and C++ to test the icuio library. For 243 information about running the test suite, see the build instructions 244 specific to your platform later in this document.</td> 245 </tr> 246 247 <tr> 248 <td><i><ICU></i>/source/test/<b>testdata</b>/</td> 249 250 <td>Source text files for data, which are read by the tests. It contains 251 the subdirectories <b>out/build/</b> which is used for intermediate 252 files, and <b>out/</b> which contains <b>testdata.dat.</b></td> 253 </tr> 254 255 <tr> 256 <td><i><ICU></i>/source/<b>tools</b>/</td> 257 258 <td>Tools for generating the data files. Data files are generated by 259 invoking <i><ICU></i>/source/data/build/makedata.bat on Win32 or 260 <i><ICU></i>/source/make on UNIX.</td> 261 </tr> 262 263 <tr> 264 <td><i><ICU></i>/source/<b>samples</b>/</td> 265 266 <td>Various sample programs that use ICU</td> 267 </tr> 268 269 <tr> 270 <td><i><ICU></i>/source/<b>extra</b>/</td> 271 272 <td>Non-supported API additions. Currently, it contains the 'uconv' tool 273 to perform codepage conversion on files.</td> 274 </tr> 275 276 <tr> 277 <td><i><ICU></i>/<b>packaging</b>/</td> 278 279 <td>This directory contain scripts and tools for packaging the final 280 ICU build for various release platforms.</td> 281 </tr> 282 283 <tr> 284 <td><i><ICU></i>/source/<b>config</b>/</td> 285 286 <td>Contains helper makefiles for platform specific build commands. Used 287 by 'configure'.</td> 288 </tr> 289 290 <tr> 291 <td><i><ICU></i>/source/<b>allinone</b>/</td> 292 293 <td>Contains top-level ICU workspace and project files, for instance to 294 build all of ICU under one MSVC project.</td> 295 </tr> 296 297 <tr> 298 <td><i><ICU></i>/<b>include</b>/</td> 299 300 <td>Contains the headers needed for developing software that uses ICU on 301 Windows.</td> 302 </tr> 303 304 <tr> 305 <td><i><ICU></i>/<b>lib</b>/</td> 306 307 <td>Contains the import libraries for linking ICU into your Windows 308 application.</td> 309 </tr> 310 311 <tr> 312 <td><i><ICU></i>/<b>bin</b>/</td> 313 314 <td>Contains the libraries and executables for using ICU on Windows.</td> 315 </tr> 316 </table> 317 318 319 320## How To Build And Install ICU 321 322### Recommended Build Options 323 324Depending on the platform and the type of installation, we recommend a small number of modifications and build options. Note that C99 compatibility is now required. 325 326* **Namespace (ICU 61 and later):** Since ICU 61, call sites need to qualify ICU types explicitly, for example `icu::UnicodeString`, or do `using icu::UnicodeString;` where appropriate. If your code relies on the "using namespace icu;" that used to be in `unicode/uversion.h`, then you need to update your code. 327 You could temporarily (until you have more time to update your code) revert to the default "using" via `-DU_USING_ICU_NAMESPACE=1` or by modifying `unicode/uversion.h`: 328 329``` 330 Index: icu4c/source/common/unicode/uversion.h 331 =================================================================== 332 --- icu4c/source/common/unicode/uversion.h (revision 40704) 333 +++ icu4c/source/common/unicode/uversion.h (working copy) 334 @@ -127,7 +127,7 @@ 335 defined(U_LAYOUTEX_IMPLEMENTATION) || defined(U_TOOLUTIL_IMPLEMENTATION) 336 # define U_USING_ICU_NAMESPACE 0 337 # else 338 -# define U_USING_ICU_NAMESPACE 0 339 +# define U_USING_ICU_NAMESPACE 1 340 # endif 341 # endif 342 # if U_USING_ICU_NAMESPACE 343``` 344 345* **Namespace (ICU 60 and earlier):** By default, unicode/uversion.h has "using namespace icu;" which defeats much of the purpose of the namespace. (This is for historical reasons: Originally, ICU4C did not use namespaces, and some compilers did not support them. The default "using" statement preserves source code compatibility.) 346 You should turn this off via `-DU_USING_ICU_NAMESPACE=0` or by modifying unicode/uversion.h: 347 348``` 349 Index: source/common/unicode/uversion.h 350 =================================================================== 351 --- source/common/unicode/uversion.h (revision 26606) 352 +++ source/common/unicode/uversion.h (working copy) 353 @@ -180,7 +180,8 @@ 354 # define U_NAMESPACE_QUALIFIER U_ICU_NAMESPACE:: 355 356 # ifndef U_USING_ICU_NAMESPACE 357 -# define U_USING_ICU_NAMESPACE 1 358 + // Set to 0 to force namespace declarations in ICU usage. 359 +# define U_USING_ICU_NAMESPACE 0 360 # endif 361 # if U_USING_ICU_NAMESPACE 362 U_NAMESPACE_USE 363``` 364 365 ICU call sites then either qualify ICU types explicitly, for example `icu::UnicodeString`, or do `using icu::UnicodeString;` where appropriate. 366* **Hardcode the default charset to UTF-8:** On platforms where the default charset is always UTF-8, like MacOS X and some Linux distributions, we recommend hardcoding ICU's default charset to UTF-8. This means that some implementation code becomes simpler and faster, and statically linked ICU libraries become smaller. (See the [U_CHARSET_IS_UTF8](http://icu-project.org/apiref/icu4c/platform_8h.html#a0a33e1edf3cd23d9e9c972b63c9f7943) API documentation for more details.) 367 You can `-DU_CHARSET_IS_UTF8=1` or modify `unicode/utypes.h` (in ICU 4.8 and below) or modify unicode/platform.h (in ICU 49 and higher): 368 369``` 370 Index: source/common/unicode/utypes.h 371 =================================================================== 372 --- source/common/unicode/utypes.h (revision 26606) 373 +++ source/common/unicode/utypes.h (working copy) 374 @@ -160,7 +160,7 @@ 375 * @see UCONFIG_NO_CONVERSION 376 */ 377 #ifndef U_CHARSET_IS_UTF8 378 -# define U_CHARSET_IS_UTF8 0 379 +# define U_CHARSET_IS_UTF8 1 380 #endif 381 382 /*===========================================================================*/ 383``` 384 385* **UnicodeString constructors:** The UnicodeString class has several single-argument constructors that are not marked "explicit" for historical reasons. This can lead to inadvertent construction of a `UnicodeString` with a single character by using an integer, and it can lead to inadvertent dependency on the conversion framework by using a C string literal. 386 Beginning with ICU 49, you should do the following: 387 * Consider marking the from-`UChar` and from-`UChar32` constructors explicit via `-DUNISTR_FROM_CHAR_EXPLICIT=explicit` or similar. 388 * Consider marking the from-`const char*` and from-`const UChar*` constructors explicit via `-DUNISTR_FROM_STRING_EXPLICIT=explicit` or similar. 389 > :point_right: **Note**: The ICU test suites cannot be compiled with these settings. 390* **utf.h, utf8.h, utf16.h, utf_old.h:** By default, utypes.h (and thus almost every public ICU header) includes all of these header files. Often, none of them are needed, or only one or two of them. All of utf_old.h is deprecated or obsolete. 391 Beginning with ICU 49, you should define `U_NO_DEFAULT_INCLUDE_UTF_HEADERS` to 1 (via -D or uconfig.h, as above) and include those header files explicitly that you actually need. 392 > :point_right: **Note**: The ICU test suites cannot be compiled with this setting. 393* **utf_old.h:** All of utf_old.h is deprecated or obsolete. 394 Beginning with ICU 60, you should define `U_HIDE_OBSOLETE_UTF_OLD_H` to 1 (via -D or uconfig.h, as above). Use of any of these macros should be replaced as noted in the comments for the obsolete macro. 395 > :point_right: **Note**: The ICU test suites _can_ be compiled with this setting. 396* **.dat file:** By default, the ICU data is built into a shared library (DLL). This is convenient because it requires no install-time or runtime configuration, but the library is platform-specific and cannot be modified. A .dat package file makes the opposite trade-off: Platform-portable (except for endianness and charset family, which can be changed with the icupkg tool) and modifiable (also with the icupkg tool). If a path is set, then single data files (e.g., .res files) can be copied to that location to provide new locale data or conversion tables etc. 397 The only drawback with a .dat package file is that the application needs to provide ICU with the file system path to the package file (e.g., by calling `u_setDataDirectory()`) or with a pointer to the data (`udata_setCommonData()`) before other ICU API calls. This is usually easy if ICU is used from an application where `main()` takes care of such initialization. It may be hard if ICU is shipped with another shared library (such as the Xerces-C++ XML parser) which does not control `main()`. 398 See the [User Guide ICU Data](https://unicode-org.github.io/icu/userguide/icudata) chapter for more details. 399 If possible, we recommend building the .dat package. Specify `--with-data-packaging=archive` on the configure command line, as in 400 `runConfigureICU Linux --with-data-packaging=archive` 401 (Read the configure script's output for further instructions. On Windows, the Visual Studio build generates both the .dat package and the data DLL.) 402 Be sure to install and use the tiny stubdata library rather than the large data DLL. 403* **Static libraries:** It may make sense to build the ICU code into static libraries (.a) rather than shared libraries (.so/.dll). Static linking reduces the overall size of the binary by removing code that is never called. 404 Example configure command line: 405 `runConfigureICU Linux --enable-static --disable-shared` 406* **Out-of-source build:** It is usually desirable to keep the ICU source file tree clean and have build output files written to a different location. This is called an "out-of-source build". Simply invoke the configure script from the target location: 407``` 408 ~/icu$ git clone https://github.com/unicode-org/icu.git 409 ~/icu$ mkdir icu4c-build 410 ~/icu$ cd icu4c-build 411 ~/icu/icu4c-build$ ../icu/icu4c/source/runConfigureICU Linux 412 ~/icu/icu4c-build$ make check</pre> 413``` 414 > :point_right: **Note**: this example shows a relative path to `runConfigureICU`. If you experience difficulty, try using an absolute path to `runConfigureICU` instead. 415 416#### ICU as a System-Level Library 417 418If ICU is installed as a system-level library, there are further opportunities and restrictions to consider. For details, see the _Using ICU as an Operating System Level Library_ section of the [User Guide ICU Architectural Design](https://unicode-org.github.io/icu/userguide/design) chapter. 419 420* **Data path:** For a system-level library, it is best to load ICU data from the .dat package file because the file system path to the .dat package file can be hardcoded. ICU will automatically set the path to the final install location using `U_ICU_DATA_DEFAULT_DIR`. Alternatively, you can set `-DICU_DATA_DIR=/path/to/icu/data` when building the ICU code. (Used by source/common/putil.c.) 421 Consider also setting `-DICU_NO_USER_DATA_OVERRIDE` if you do not want the `ICU_DATA` environment variable to be used. (An application can still override the data path via `u_setDataDirectory()` or `udata_setCommonData()`. 422* **Hide draft API:** API marked with `@draft` is new and not yet stable. Applications must not rely on unstable APIs from a system-level library. Define `U_HIDE_DRAFT_API`, `U_HIDE_INTERNAL_API` and `U_HIDE_SYSTEM_API` by modifying `unicode/utypes.h` before installing it. 423* **Only C APIs:** Applications must not rely on C++ APIs from a system-level library because binary C++ compatibility across library and compiler versions is very hard to achieve. Most ICU C++ APIs are in header files that contain a comment with `\brief C++ API`. Consider not installing these header files, or define `U_SHOW_CPLUSPLUS_API` to be `0` by modifying `unicode/utypes.h` before installing it. 424* **Disable renaming:** By default, ICU library entry point names have an ICU version suffix. Turn this off for a system-level installation, to enable upgrading ICU without breaking applications. For example: 425 `runConfigureICU Linux --disable-renaming` 426 The public header files from this configuration must be installed for applications to include and get the correct entry point names. 427 428### User-Configurable Settings 429 430ICU4C can be customized via a number of user-configurable settings. Many of them are controlled by preprocessor macros which are defined in the `source/common/unicode/uconfig.h` header file. Some turn off parts of ICU, for example conversion or collation, trading off a smaller library for reduced functionality. Other settings are recommended (see previous section) but their default values are set for better source code compatibility. 431 432In order to change such user-configurable settings, you can either modify the `uconfig.h` header file by adding a specific `#define ...` for one or more of the macros before they are first tested, or set the compiler's preprocessor flags (`CPPFLAGS`) to include an equivalent `-D` macro definition. 433 434### How To Build And Install On Windows 435 436Building International Components for Unicode requires: 437 438* Microsoft Windows 439* Microsoft Visual C++ (part of [Visual Studio](https://www.visualstudio.com/)) (from either Visual Studio 2015 or Visual Studio 2017) 440* _**Optional:**_ A version of the [Windows 10 SDK](https://developer.microsoft.com/windows/downloads) (if you want to build the UWP projects) 441 442> :point_right: **Note**: [Cygwin](#how-to-build-and-install-on-windows-with-cygwin) is required if using a version of MSVC other than the one compatible with the supplied project files or if other compilers are used to build ICU. (e.g. GCC) 443 444The steps are: 445 4461. Unzip the `icu-XXXX.zip` file into any convenient location. 447 * You can use the built-in zip functionality of Windows Explorer to do this. Right-click on the .zip file and choose the "Extract All" option from the context menu. This will open a new window where you can choose the output location to put the files. 448 * Alternatively, you can use a 3<sup>rd</sup> party GUI tool like 7-Zip or WinZip to do this as well. 4492. Be sure that the ICU binary directory, (ex: `<ICU>\bin\`), is included in the **PATH** environment variable. The tests will not work without the location of the ICU DLL files in the path. Note that the binary directory name can depend on what architecture you select when you compile ICU. For x86 or 32-bit builds, the binary directory is `bin`. Whereas for x64 or 64-bit builds the binary directory is `bin64`. 4503. Open the `<ICU>\source\allinone\allinone.sln` solution file in 'Visual Studio 2017'. (This solution includes all the International Components for Unicode libraries, necessary ICU building tools, and the test suite projects). Please see the [command line note below](#using-msbuild-at-the-command-line) if you want to build from the command line instead. 4514. If you are building using 'Visual Studio 2015' instead, or if you are building the UWP projects and you have a different version of the Windows 10 SDK installed you will first need to modify the two `Build.Windows.*.props` files in the `allinone` directory before you can open the "allinone" solution file. Please see the notes below about [building with other versions of Visual Studio](#building-with-other-versions-of-visual-studio) and the notes on [re-targeting the Windows 10 SDK for the UWP projects](#re-targeting-the-windows-10-sdk-for-the-uwp-projects) for details. Alternatively, you can [skip building the UWP projects](#re-targeting-the-windows-10-sdk-for-the-uwp-projects) entirely as well. 4525. Set the active platform to "Win32" or "x64" (See [Windows platform note](#setting-active-platform) below) and configuration to "Debug" or "Release" (See [Windows configuration note](#setting-active-configuration) below). 4536. Choose the "Build" menu and select "Rebuild Solution". If you want to build the Debug and Release at the same time, see the [batch configuration note](#batch-configuration) below. 4547. Run the tests. They can be run from the command line or from within Visual Studio. 455 456 #### Running the Tests from the Windows Command Line (cmd) 457 458 * The general syntax is: 459 460 <pre> 461 <ICU>\source\allinone\icucheck.bat <i>Platform</i> <i>Configuration</i> 462 </pre> 463 464 * So, for example for x86 (32-bit) and Debug, use the following: 465 ``` 466 <ICU>\source\allinone\icucheck.bat x86 Debug 467 ``` 468 For x86 (32-bit) and Release: 469 ``` 470 <ICU>\source\allinone\icucheck.bat x86 Release 471 ``` 472 For x64 (64-bit) and Debug: 473 ``` 474 <ICU>\source\allinone\icucheck.bat x64 Debug 475 ``` 476 For x64 (64-bit) and Release: 477 ``` 478 <ICU>\source\allinone\icucheck.bat x64 Release 479 ``` 480 481 #### Running the Tests from within Visual Studio 482 483 1. Run the C++ test suite, `intltest`. To do this: set the active startup project to "intltest", and press Ctrl+F5 to run it. Make sure that it passes without any errors. 484 2. Run the C test suite, `cintltst`. To do this: set the active startup project to "cintltst", and press Ctrl+F5 to run it. Make sure that it passes without any errors. 485 3. Run the I/O test suite, `iotest`. To do this: set the active startup project to "iotest", and press Ctrl+F5 to run it. Make sure that it passes without any errors. 4868. You are now able to develop applications with ICU by using the libraries and tools in `<ICU>\bin\`. The headers are in `<ICU>\include\` and the link libraries are in `<ICU>\lib\`. To install the ICU runtime on a machine, or ship it with your application, copy the needed components from `<ICU>\bin\` to a location on the system PATH or to your application directory. 487 488#### Building with other versions of Visual Studio 489 490The particular version of the MSVC compiler tool-set (and thus the corresponding version of Visual Studio) that is used to compile ICU is determined by the `PlatformToolset` property. This property is stored in two different shared files that are used to set common configuration settings amongst the various ICU `*.vcxproj` project files. For the non-UWP projects, this setting is in the shared file called `Build.Windows.ProjectConfiguration.props` located in the `allinone` directory. For the UWP projects, this setting is in the shared file called `Build.Windows.UWP.ProjectConfiguration.props`, also located in the `allinone` directory. 491 492The value of `v140` corresponds to the Visual Studio 2015 compiler tool set, whereas the value of `v141` corresponds to the Visual Studio 2017 compiler tool set. 493 494In order to build the non-UWP projects with Visual Studio 2015 you will need to modify the file called `Build.Windows.ProjectConfiguration.props` to change the value of the `PlatformToolset` property. Note however that Visual Studio 2017 is required for building the UWP projects. 495 496> :point_right: **Note**: Using older versions of the MSVC compiler is generally not recommended due to the improved support for the C++11 standard in newer versions of the compiler. 497 498#### Re-targeting the Windows 10 SDK for the UWP projects 499 500If the version of the Windows 10 SDK that you have installed does not match the version used by the UWP projects, then you will need to "retarget" them to use the version of the SDK that you have installed instead. There are two ways to do this: 501 502* In Visual Studio you can right-click on the UWP projects in the 'Solution Explorer' and select the option 'Retarget Projects' from the context menu. This will open up a window where you can select the SDK version to target from a drop-down list of the various SDKs that are installed on the machine. 503* Alternatively, you can manually edit the shared file called `Build.Windows.UWP.ProjectConfiguration.props` which is located in the `allinone` directory. You will need to change the of the `WindowsTargetPlatformVersion` property to the version of the SDK that you would like to use instead. 504 505#### Using MSBUILD At The Command Line 506 507You can build ICU from the command line instead of using the Visual Studio GUI. Assuming that you have properly installed Visual Studio to support command line building, you should have a shortcut for the "Developer Command Prompt" listed in the Start Menu. (For Visual Studio 2017 you will need to install the "Desktop development with C++" option). 508 509* Open the "Developer Command Prompt" shortcut from the Start Menu. (This will open up a new command line window). 510* From within the "Developer Command Prompt" change directory (`cd`) to the ICU source directory. 511* You can then use either `msbuild` directly, or you can use the `devenv.com` command to build ICU. 512* Using `MSBUILD`: 513 - To build the 32-bit Debug version, use the following command line: 514 ``` 515 msbuild source\allinone\allinone.sln /p:Configuration=Debug /p:Platform=Win32 516 ``` 517 - To build the 64-bit Release version, use the following command line: 518 ``` 519 msbuild source\allinone\allinone.sln /p:Configuration=Release /p:Platform=x64 520 ``` 521* Using `devenv.com`: 522 - To build the 32-bit Debug version, use the following command line: 523 ``` 524 devenv.com source\allinone\allinone.sln /build "Debug|Win32" 525 ``` 526 - To build the 64-bit Release version, use the following command line: 527 ``` 528 devenv.com source\allinone\allinone.sln /build "Release|x64" 529 ``` 530 531#### Skipping the UWP Projects on the Command Line 532 533You can skip (or omit) building the UWP projects on the command line by passing the argument '`SkipUWP=true`' to either MSBUILD or devenv. 534 535* For example, using `MSBUILD`: 536 - To skip building the UWP projects with a 32-bit Debug build, use the following command line: 537 ``` 538 msbuild source\allinone\allinone.sln /p:Configuration=Debug /p:Platform=Win32 /p:SkipUWP=true 539 ``` 540 - To skip building the UWP projects with a 64-bit Release version, use the following command line: 541 ``` 542 msbuild source\allinone\allinone.sln /p:Configuration=Release /p:Platform=x64 /p:SkipUWP=true 543 ``` 544 545You can also use Cygwin with the MSVC compiler to build ICU, and you can refer to the [How To Build And Install On Windows with Cygwin](#how-to-build-and-install-on-windows-with-cygwin) section for more details. 546 547#### Setting Active Platform 548 549Even though you are able to select "x64" as the active platform, if your operating system is not a 64 bit version of Windows, the build will fail. To set the active platform, two different possibilities are: 550 551* Choose "Build" menu, select "Configuration Manager...", and select "Win32" or "x64" for the Active Platform Solution. 552* Another way is to select the desired build configuration from "Solution Platforms" dropdown menu from the standard toolbar. It will say "Win32" or "x64" in the dropdown list. 553 554#### Setting Active Configuration 555 556To set the active configuration, two different possibilities are: 557 558* Choose "Build" menu, select "Configuration Manager...", and select "Release" or "Debug" for the Active Configuration Solution. 559* Another way is to select the desired build configuration from "Solution Configurations" dropdown menu from the standard toolbar. It will say "Release" or "Debug" in the dropdown list. 560 561#### Batch Configuration 562 563If you want to build the Win32 and x64 platforms and Debug and Release configurations at the same time, choose "Build" menu, and select "Batch Build...". Click the "Select All" button, and then click the "Rebuild" button. 564 565### How To Build And Install On Windows with Cygwin 566 567Building International Components for Unicode with this configuration requires: 568 569* Microsoft Windows 570* Microsoft Visual C++ (from Visual Studio 2015 or newer, when gcc isn't used). 571* Cygwin with the following installed: 572 * bash 573 * GNU make 574 * ar 575 * ranlib 576 * man (if you plan to look at the man pages) 577 578There are two ways you can build ICU with Cygwin. You can build with gcc or Microsoft Visual C++. If you use gcc, the resulting libraries and tools will depend on the Cygwin environment. If you use Microsoft Visual C++, the resulting libraries and tools do not depend on Cygwin and can be more easily distributed to other Windows computers (the generated man pages and shell scripts still need Cygwin). To build with gcc, please follow the "[How To Build And Install On UNIX](#how-to-build-and-install-on-unix)" instructions, while you are inside a Cygwin bash shell. To build with Microsoft Visual C++, please use the following instructions: 579 5801. Start the Windows "Command Prompt" window. This is different from the gcc build, which requires the Cygwin Bash command prompt. The Microsoft Visual C++ compiler will not work with a bash command prompt. 5812. If the computer isn't set up to use Visual C++ from the command line, you need to run vcvars32.bat. 582 For example: 583 `C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\vcvars32.bat` can be used for 32-bit builds **or** 584 `C:\Program Files (x86)\Microsoft Visual Studio 14\VC\bin\x86_amd64\vcvarsx86_amd64.bat` can be used for 64-bit builds on Windows x64. 5853. Unzip the icu-XXXX.zip file into any convenient location. Using command line zip, type "unzip -a icu-XXXX.zip -d drive:\directory", or just use WinZip. 5864. Change directory to "icu/source", which is where you unzipped ICU. 5875. Run `bash ./runConfigureICU Cygwin/MSVC` (See [Windows configuration note](#setting-active-configuration) and non-functional configure options below; see source for [./runConfigureICU](https://github.com/unicode-org/icu/blob/master/icu4c/source/runConfigureICU)). 5886. Type `make` to compile the libraries and all the data files. This make command should be GNU make. 5897. Optionally, type `make check` to run the test suite, which checks for ICU's functionality integrity (See [testing note](#running-the-tests-from-the-command-line) below). 5908. Type `make install` to install ICU. If you used the `--prefix=` option on `configure` or `runConfigureICU`, ICU will be installed to the directory you specified. (See [installation note](#installing-icu) below). 591 592#### Configuring ICU on Windows 593 594Ensure that the order of the PATH is MSVC, Cygwin, and then other PATHs. The configure script needs certain tools in Cygwin (e.g. grep). 595 596Also, you may need to run `dos2unix.exe` on all of the scripts (e.g. `configure`) in the top source directory of ICU. To avoid this issue, you can download the ICU source for Unix platforms (icu-xxx.tgz). 597 598In addition to the Unix [configuration note](#configuring-icu) the following configure options currently do not work on Windows with Microsoft's compiler. Some options can work by manually editing `icu/source/common/unicode/pwin32.h`, but manually editing the files is not recommended. 599 600* `--disable-renaming` 601* `--enable-tracing` 602* `--enable-rpath` 603* `--enable-static` (Requires that U_STATIC_IMPLEMENTATION be defined in user code that links against ICU's static libraries.) 604* `--with-data-packaging=files` (The pkgdata tool currently does not work in this mode. Manual packaging is required to use this mode.) 605 606### How To Build And Install On UNIX 607 608Building International Components for Unicode on UNIX requires: 609 610* A C++ compiler installed on the target machine (for example: gcc, CC, xlC_r, aCC, cxx, etc...). 611* An ANSI C compiler installed on the target machine (for example: cc). 612* A recent version of GNU make (3.80+). 613* For a list of z/OS tools please view the [z/OS build section](#how-to-build-and-install-on-zos-os390) of this document for further details. 614 615Here are the steps to build ICU: 616 6171. Decompress the icu-_X_._Y_.tgz (or icu-_X_._Y_.tar.gz) file. For example, 618 ``` 619 gunzip -d < icu-_X_._Y_.tgz | tar xvf - 620 ``` 6211. Change directory to `icu/source`. 622 ``` 623 cd icu/source 624 ``` 6251. Some files may have the wrong permissions. 626 ``` 627 chmod +x runConfigureICU configure install-sh 628 ``` 6291. Run the [`runConfigureICU`](https://github.com/unicode-org/icu/blob/master/icu4c/source/runConfigureICU) script for your platform. (See [configuration note](#configuring-icu) below). 6301. Now build: 631``` 632gmake 633``` 634 (or just `make` if GNU make is the default make on your platform) to compile the libraries and all the data files. The proper name of the GNU make command is printed at the end of the configuration run, as in `"You must use gmake to compile ICU"`. 635 Note that the compilation command output may be simplified on your platform. If this is the case, you will see just: `gcc ... stubdata.c` rather than `gcc -DU_NO_DEFAULT_INCLUDE_UTF_HEADERS=1 -D_REENTRANT -I../common -DU_ATTRIBUTE_DEPRECATED= -O2 -Wall -std=c99 -pedantic -Wshadow -Wpointer-arith -Wmissing-prototypes -Wwrite-strings -c -DPIC -fPIC -o stubdata.o stubdata.c` 636 If you need to see the whole compilation line, use `gmake VERBOSE=1`. The full compilation line will print if an error occurs. 6371. Optionally, 638``` 639gmake check 640``` 641 will run the test suite, which checks for ICU's functionality integrity (See [testing note](#running-the-tests-from-the-command-line) below). 6421. To install, 643``` 644gmake install 645``` 646 to install ICU. If you used the `--prefix=` option on `configure` or `runConfigureICU`, ICU will be installed to the directory you specified. (See [installation note](#installing-icu) below). 647 648#### Configuring ICU 649 650Type `"./runConfigureICU --help"` for help on how to run it and a list of supported platforms. You may also want to type `"./configure --help"` to print the available configure options that you may want to give `runConfigureICU`. If you are not using the `runConfigureICU` script, or your platform is not supported by the script, you may need to set your `CC`, `CXX`, `CFLAGS` and `CXXFLAGS` environment variables, and type `"./configure"`. HP-UX users, please see this [note regarding HP-UX multithreaded build issues](#using-icu-in-a-multithreaded-environment-on-hp-ux) with newer compilers. Solaris users, please see this [note regarding Solaris multithreaded build issues](#linking-on-solaris). 651 652ICU is built with strict compiler warnings enabled by default. If this causes excessive numbers of warnings on your platform, use the `--disable-strict` option to configure to reduce the warning level. 653 654#### Running The Tests From The Command Line 655 656You may have to set certain variables if you with to run test programs individually, that is apart from "gmake check". The environment variable **ICU_DATA** can be set to the full pathname of the data directory to indicate where the locale data files and conversion mapping tables are when you are not using the shared library (e.g. by using the .dat archive or the individual data files). The trailing "/" is required after the directory name (e.g. `$Root/source/data/out/` will work, but the value `$Root/source/data/out` is not acceptable). You do not need to set **ICU_DATA** if the complete shared data library is in your library path. 657 658#### Installing ICU 659 660Some platforms use package management tools to control the installation and uninstallation of files on the system, as well as the integrity of the system configuration. You may want to check if ICU can be packaged for your package management tools by looking into the `packaging` directory. (Please note that if you are using a snapshot of ICU from Git, it is probable that the packaging scripts or related files are not up to date with the contents of ICU at this time, so use them with caution). 661 662### How To Build And Install On z/OS (OS/390) 663 664You can install ICU on z/OS or OS/390 (the previous name of z/OS), but IBM tests only the z/OS installation. You install ICU in a z/OS UNIX system services file system such as HFS or zFS. On this platform, it is important that you understand a few details: 665 666* The makedep and GNU make tools are required for building ICU. If it is not already installed on your system, it is available at the [z/OS UNIX - Tools and Toys](http://www-03.ibm.com/servers/eserver/zseries/zos/unix/bpxa1toy.html) site. The PATH environment variable should be updated to contain the location of this executable prior to build. Failure to add these tools to your PATH will cause ICU build failures or cause pkgdata to fail to run. 667* Since USS does not support using the mmap() function over NFS, it is recommended that you build ICU on a local filesystem. Once ICU has been built, you should not have this problem while using ICU when the data library has been built as a shared library, which is this is the default setting. 668* Encoding considerations: The source code assumes that it is compiled with codepage ibm-1047 (to be exact, the UNIX System Services variant of it). The pax command converts all of the source code files from ASCII to codepage ibm-1047 (USS) EBCDIC. However, some files are binary files and must not be converted, or must be converted back to their original state. You can use the [unpax-icu.sh](https://github.com/unicode-org/icu/blob/master/icu4c/as_is/os390/unpax-icu.sh) script to do this for you automatically. It will unpackage the tar file and convert all the necessary files for you automatically. 669* z/OS supports both native S/390 hexadecimal floating point and (with OS/390 2.6 and later) IEEE 754 binary floating point. This is a compile time option. Applications built with IEEE should use ICU DLLs that are built with IEEE (and vice versa). The environment variable IEEE390=0 will cause the z/OS version of ICU to be built without IEEE floating point support and use the native hexadecimal floating point. By default ICU is built with IEEE 754 support. Native floating point support is sufficient for codepage conversion, resource bundle and UnicodeString operations, but the Format APIs require IEEE binary floating point. 670* z/OS introduced the concept of Extra Performance Linkage (XPLINK) to bring performance improvement opportunities to call-intensive C and C++ applications such as ICU. XPLINK is enabled on a DLL-by-DLL basis, so if you are considering using XPLINK in your application that uses ICU, you should consider building the XPLINK-enabled version of ICU. You need to set ICU's environment variable `OS390_XPLINK=1` prior to invoking the make process to produce binaries that are enabled for XPLINK. The XPLINK option, which is available for z/OS 1.2 and later, requires the PTF PQ69418 to build XPLINK enabled binaries. 671* ICU requires XPLINK for the icuio library. If you want to use the rest of ICU without XPLINK, then you must use the --disable-icuio configure option. 672* The latest versions of z/OS use [XPLINK version (C128) of the C++ standard library](https://www.ibm.com/support/knowledgecenter/SSLTBW_2.2.0/com.ibm.zos.v2r2.cbcux01/oebind6.htm) by default. You may see [an error](https://www.ibm.com/support/knowledgecenter/SSLTBW_2.2.0/com.ibm.zos.v2r2.cbcux01/oebind5.htm) when running with XPLINK disabled. To avoid this error, set the following environment variable or similar: 673 674``` 675export _CXX_PSYSIX="CEE.SCEELIB(C128N)":"CBC.SCLBSID(IOSTREAM,COMPLEX)" 676``` 677 678* When building ICU data, the heap size may need to be increased with the following environment variable: 679 680``` 681export _CEE_RUNOPTS="HEAPPOOLS(ON),HEAP(4M,1M,ANY,FREE,0K,4080)" 682``` 683 684* The rest of the instructions for building and testing ICU on z/OS with UNIX System Services are the same as the [How To Build And Install On UNIX](#how-to-build-and-install-on-unix) section. 685 686#### z/OS (Batch/PDS) support outside the UNIX system services environment 687 688By default, ICU builds its libraries into the UNIX file system (HFS). In addition, there is a z/OS specific environment variable (OS390BATCH) to build some libraries into the z/OS native file system. This is useful, for example, when your application is externalized via Job Control Language (JCL). 689 690The OS390BATCH environment variable enables non-UNIX support including the batch environment. When OS390BATCH is set, the libicui18n_XX_.dll, libicuuc_XX_.dll, and libicudt_XX_e.dll binaries are built into data sets (the native file system). Turning on OS390BATCH does not turn off the normal z/OS UNIX build. This means that the z/OS UNIX (HFS) DLLs will always be created. 691 692Two additional environment variables indicate the names of the z/OS data sets to use. The LOADMOD environment variable identifies the name of the data set that contains the dynamic link libraries (DLLs) and the LOADEXP environment variable identifies the name of the data set that contains the side decks, which are normally the files with the .x suffix in the UNIX file system. 693 694A data set is roughly equivalent to a UNIX or Windows file. For most kinds of data sets the operating system maintains record boundaries. UNIX and Windows files are byte streams. Two kinds of data sets are PDS and PDSE. Each data set of these two types contains a directory. It is like a UNIX directory. Each "file" is called a "member". Each member name is limited to eight bytes, normally EBCDIC. 695 696Here is an example of some environment variables that you can set prior to building ICU: 697 698``` 699OS390BATCH=1 700LOADMOD=_USER_.ICU.LOAD 701LOADEXP=_USER_.ICU.EXP 702``` 703 704The PDS member names for the DLL file names are as follows: 705 706``` 707IXMI_XX_IN --> libicui18n_XX_.dll 708IXMI_XX_UC --> libicuuc_XX_.dll 709IXMI_XX_DA --> libicudt_XX_e.dll 710``` 711 712You should point the LOADMOD environment variable at a partitioned data set extended (PDSE) and point the LOADEXP environment variable at a partitioned data set (PDS). The PDSE can be allocated with the following attributes: 713 714``` 715Data Set Name . . . : USER.ICU.LOAD 716Management class. . : **None** 717Storage class . . . : BASE 718Volume serial . . . : TSO007 719Device type . . . . : 3390 720Data class. . . . . : LOAD 721Organization . . . : PO 722Record format . . . : U 723Record length . . . : 0 724Block size . . . . : 32760 7251st extent cylinders: 1 726Secondary cylinders : 5 727Data set name type : LIBRARY 728``` 729 730The PDS can be allocated with the following attributes: 731 732``` 733Data Set Name . . . : USER.ICU.EXP 734Management class. . : **None** 735Storage class . . . : BASE 736Volume serial . . . : TSO007 737Device type . . . . : 3390 738Data class. . . . . : **None** 739Organization . . . : PO 740Record format . . . : FB 741Record length . . . : 80 742Block size . . . . : 3200 7431st extent cylinders: 3 744Secondary cylinders : 3 745Data set name type : PDS 746``` 747 748### How To Build And Install On The IBM i Family (IBM i, i5/OS OS/400) 749 750Before you start building ICU, ICU requires the following: 751 752* QSHELL interpreter installed (install base option 30, operating system) 753* ILE C/C++ Compiler installed on the system 754* The latest IBM tools for Developers for IBM i — [https://www-356.ibm.com/partnerworld/wps/servlet/ContentHandler/pw_com_porting_tools_index](https://www-356.ibm.com/partnerworld/wps/servlet/ContentHandler/pw_com_porting_tools_index) 755 756The following describes how to setup and build ICU. For background information, you should look at the [UNIX build instructions](#how-to-build-and-install-on-unix). 757 7581. Copy the ICU source .tgz to the IBM i environment, as binary. Also, copy the [unpax-icu.sh](https://github.com/unicode-org/icu/blob/master/icu4c/as_is/os400/unpax-icu.sh) script into the same directory, as a text file. 7592. Create target library. This library will be the target for the resulting modules, programs and service programs. You will specify this library on the OUTPUTDIR environment variable. 760``` 761CRTLIB LIB(_libraryname_) 762ADDENVVAR ENVVAR(OUTPUTDIR) VALUE('_libraryname_') REPLACE(*YES) 763``` 7643. Set up the following environment variables and job characteristics in your build process 765``` 766ADDENVVAR ENVVAR(MAKE) VALUE('gmake') REPLACE(*YES) 767CHGJOB CCSID(37) 768``` 7694. Fire up the QSH _(all subsequent commands are run inside the qsh session.)_ 770``` 771qsh 772``` 7735. Set up the PATH: 774``` 775export PATH=/QIBM/ProdData/DeveloperTools/qsh/bin:$PATH:/QOpenSys/usr/bin 776``` 7776. Unpack the ICU source code archive: 778``` 779gzip -d icu-_X_._Y_.tgz 780``` 7817. Run unpax-icu.sh on the tar file generated from the previous step. 782``` 783unpax-icu.sh icu.tar 784``` 7858. Build the program ICULD which ICU will use for linkage. 786``` 787cd icu/as_is/os400 788qsh bldiculd.sh 789cd ../../.. 790``` 7919. Change into the 'source' directory, and configure ICU. (See [configuration note](#HowToConfigureICU) for details). Note that --with-data-packaging=archive and setting the --prefix are recommended, building in default (dll) mode is currently not supported. 792``` 793cd icu/source 794./runConfigureICU IBMi --prefix=_/path/to/somewhere_ --with-data-packaging=archive 795``` 79610. Build ICU. 797> :point_right: **Note**: Do not use the -j option 798``` 799gmake 800``` 80111. Test ICU. 802``` 803gmake check 804``` 805(The `QIBM_MULTI_THREADED=Y` flag will be automatically applied to intltest - you can look at the [iSeries Information Center](https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_73/rzahw/rzahwceeco.htm) for more details regarding the running of multiple threads on IBM i.) 806 807### How To Cross Compile ICU 808 809This section will explain how to build ICU on one platform, but to produce binaries intended to run on another. This is commonly known as a cross compile. 810 811Normally, in the course of a build, ICU needs to run the tools that it builds in order to generate and package data and test-data. In a cross compilation setting, ICU is built on a different system from that which it eventually runs on. An example might be, if you are building for a small/headless system (such as an embedded device), or a system where you can't easily run the ICU command line tools (any non-UNIX-like system). 812 813To reduce confusion, we will here refer to the "A" and the "B" system. System "A" is the actual system we will be running on - the only requirements on it is are it is able to build ICU from the command line targetting itself (with `configure` or `runConfigureICU`), and secondly, that it also contain the correct toolchain for compiling and linking for the resultant platform, referred to as the "B" system. 814 815The autoconf docs use the term "build" for A, and "host" for B. More details at: [http://www.gnu.org/software/autoconf/manual/html_node/Specifying-Names.html](http://www.gnu.org/software/autoconf/manual/html_node/Specifying-Names.html#Specifying-Names) 816 817Three initially-empty directories will be used in this example: 818 819| **/icu** | a copy of the ICU source | 820| **/buildA** | an empty directory, it will contain ICU built for A (MacOSX in this case) | 821| **/buildB** | an empty directory, it will contain ICU built for B (HaikuOS in this case) | 822 8231. Check out or unpack the ICU source code into the `/icu` directory.You will have the directories `/icu/source`, etc. 8242. Build ICU in `/buildA` normally (using `runConfigureICU` or `configure`): 825``` 826cd /buildA 827sh /icu/source/runConfigureICU MacOSX 828gnumake 829``` 8303. Set `PATH` or other variables as needed, such as `CPPFLAGS`. 8314. Build ICU in `/buildB` 832``` 833cd /buildB 834sh /icu/source/configure --host=i586-pc-haiku--with-cross-build=/buildA 835gnumake 836``` 837> :point_right: **Note**: `--with-cross-build` takes an absolute path. 8385. Tests and testdata can be built with `gnumake tests`. 839 840## How To Package ICU 841 842There are many ways that a person can package ICU with their software products. Usually only the libraries need to be considered for packaging. 843 844On UNIX, you should use `gmake install` to make it easier to develop and package ICU. The bin, lib and include directories are needed to develop applications that use ICU. These directories will be created relative to the `--prefix=`dir" configure option (See the [UNIX build instructions](#how-to-build-and-install-on-unix)). When ICU is built on Windows, a similar directory structure is built. 845 846When changes have been made to the standard ICU distribution, it is recommended that at least one of the following guidelines be followed for special packaging. 847 8481. Add a suffix name to the library names. This can be done with the `--with-library-suffix` configure option. 8492. The installation script should install the ICU libraries into the application's directory. 850 851Following these guidelines prevents other applications that use a standard ICU distribution from conflicting with any libraries that you need. On operating systems that do not have a standard C++ ABI (name mangling) for compilers, it is recommended to do this special packaging anyway. More details on customizing ICU are available in the [User's Guide](https://unicode-org.github.io/icu/userguide/). The [ICU Source Code Organization](#SourceCode) section of this readme.html gives a more complete description of the libraries. 852 853ICU has several libraries for you to use. Here is an example of libraries that are frequently packaged. 854 855| Library Name | Windows Filename | Linux Filename | Comment | 856|-------------------------------------|------------------|------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| 857| Data Library | icudtXYl.dll | libicudata.so.XY.Z | Data required by the Common and I18n libraries. There are many ways to package and [customize this data](https://unicode-org.github.io/icu/userguide/icudata), but by default this is all you need. | 858| Common Library | icuucXY.dll | libicuuc.so.XY.Z | Base library required by all other ICU libraries. | 859| Internationalization (i18n) Library | icuinXY.dll | libicui18n.so.XY.Z | A library that contains many locale based internationalization (i18n) functions. | 860| Layout Extensions Engine | iculxXY.dll | libiculx.so.XY.Z | An optional engine for doing paragraph layout that uses parts of ICU. HarfBuzz is required. | 861| ICU I/O (Unicode stdio) Library | icuioXY.dll | libicuio.so.XY.Z | An optional library that provides a stdio like API with Unicode support. | 862| Tool Utility Library | icutuXY.dll | libicutu.so.XY.Z | An internal library that contains internal APIs that are only used by ICU's tools. If you do not use ICU's tools, you do not need this library. | 863 864 865Normally only the above ICU libraries need to be considered for packaging. The versionless symbolic links to these libraries are only needed for easier development. The _X_, _Y_ and _Z_ parts of the name are the version numbers of ICU. For example, ICU 2.0.2 would have the name libicuuc.so.20.2 for the common library. The exact format of the library names can vary between platforms due to how each platform can handles library versioning. 866 867## Important Notes About Using ICU 868 869### Using ICU in a Multithreaded Environment 870 871Some versions of ICU require calling the `u_init()` function from `uclean.h` to ensure that ICU is initialized properly. In those ICU versions, `u_init()` must be called before ICU is used from multiple threads. There is no harm in calling `u_init()` in a single-threaded application, on a single-CPU machine, or in other cases where `u_init()` is not required. 872 873In addition to ensuring thread safety, `u_init()` also attempts to load at least one ICU data file. Assuming that all data files are packaged together (or are in the same folder in files mode), a failure code from `u_init()` usually means that the data cannot be found. In this case, the data may not be installed properly, or the application may have failed to call `udata_setCommonData()` or `u_setDataDirectory()` which specify to ICU where it can find its data. 874 875Since `u_init()` will load only one or two data files, it cannot guarantee that all of the data that an application needs is available. It cannot check for all data files because the set of files is customizable, and some ICU services work without loading any data at all. An application should always check for error codes when opening ICU service objects (using `ucnv_open()`, `ucol_open()`, C++ constructors, etc.). 876 877#### ICU 3.4 and later 878 879ICU 3.4 self-initializes properly for multi-threaded use. It achieves this without performance penalty by hardcoding the core Unicode properties data, at the cost of some flexibility. (For details see Jitterbug 4497.) 880 881`u_init()` can be used to check for data loading. It tries to load the converter alias table (`cnvalias.icu`). 882 883#### ICU 2.6..3.2 884 885These ICU versions require a call to `u_init()` before multi-threaded use. The services that are directly affected are those that don't have a service object and need to be fast: normalization and character properties. 886 887`u_init()` loads and initializes the data files for normalization and character properties (`unorm.icu` and `uprops.icu`) and can therefore also be used to check for data loading. 888 889#### ICU 2.4 and earlier 890 891ICU 2.4 and earlier versions were not prepared for multithreaded use on multi-CPU platforms where the CPUs implement weak memory coherency. These CPUs include: Power4, Power5, Alpha, Itanium. `u_init()` was not defined yet. 892 893#### Using ICU in a Multithreaded Environment on HP-UX 894 895When ICU is built with aCC on HP-UX, the [`-AA`](http://h21007.www2.hp.com/portal/site/dspp/menuitem.863c3e4cbcdc3f3515b49c108973a801?ciid=eb08b3f1eee02110b3f1eee02110275d6e10RCRD) compiler flag is used. It is required in order to use the latest `<iostream>` API in a thread safe manner. This compiler flag affects the version of the C++ library being used. Your applications will also need to be compiled with `-AA` in order to use ICU. 896 897#### Using ICU in a Multithreaded Environment on Solaris 898 899##### Linking on Solaris 900 901In order to avoid synchronization and threading issues, developers are **suggested** to strictly follow the compiling and linking guidelines for multithreaded applications, specified in the following SUn Solaris document available from Oracle. Most notably, pay strict attention to the following statements from Sun: 902 903> To use libthread, specify `-lthread` before `-lc` on the ld command line, or last on the cc command line. 904> 905> To use libpthread, specify `-lpthread` before `-lc` on the ld command line, or last on the cc command line. 906 907Failure to do this may cause spurious lock conflicts, recursive mutex failure, and deadlock. 908 909Source: "_Multithreaded Programming Guide, Compiling and Debugging_", Sun Microsystems, 2002 910[https://docs.oracle.com/cd/E19683-01/806-6867/compile-74765/index.html](https://docs.oracle.com/cd/E19683-01/806-6867/compile-74765/index.html) 911 912Note, a version of that chapter from a 2008 document update covering both Solaris 9 and Solaris 10 is available here: 913[http://docs.oracle.com/cd/E19253-01/816-5137/compile-94179/index.html](http://docs.oracle.com/cd/E19253-01/816-5137/compile-94179/index.html) 914 915### Windows Platform 916 917If you are building on the Windows platform, it is important that you understand a few of the following build details. 918 919#### DLL directories and the PATH setting 920 921As delivered, the International Components for Unicode build as several DLLs, which are placed in the `<ICU>\bin64` directory. You must add this directory to the PATH environment variable in your system, or any executables you build will not be able to access International Components for Unicode libraries. Alternatively, you can copy the DLL files into a directory already in your PATH, but we do not recommend this. You can wind up with multiple copies of the DLL and wind up using the wrong one. 922 923#### Changing your PATH 924 925##### Windows 2000/XP and above 926 927Use the System Icon in the Control Panel. Pick the "Advanced" tab. Select the "Environment Variables..." button. Select the variable `PATH` in the lower box, and select the lower "Edit..." button. In the "Variable Value" box, append the string `;<ICU>\bin64` to the end of the path string. If there is nothing there, just type in `<ICU>\bin64`. Click the Set button, then the OK button. 928 929> :point_right: **Note**: When packaging a Windows application for distribution and installation on user systems, copies of the ICU DLLs should be included with the application, and installed for exclusive use by the application. This is the only way to insure that your application is running with the same version of ICU, built with exactly the same options, that you developed and tested with. Refer to Microsoft's guidelines on the usage of DLLs, or search for the phrase "DLL hell" on [msdn.microsoft.com](http://msdn.microsoft.com/). 930 931### UNIX Type Platform 932 933If you are building on a UNIX platform, and if you are installing ICU in a non-standard location, you may need to add the location of your ICU libraries to your `LD_LIBRARY_PATH` or `LIBPATH` environment variable (or the equivalent runtime library path environment variable for your system). The ICU libraries may not link or load properly without doing this. 934 935> :point_right: **Note**: If you do not want to have to set this variable, you may instead use the `--enable-rpath` option at configuration time. This option will instruct the linker to always look for the libraries where they are installed. You will need to use the appropriate linker options when linking your own applications and libraries against ICU, too. Please refer to your system's linker manual for information about runtime paths. The use of rpath also means that when building a new version of ICU you should not have an older version installed in the same place as the new version's installation directory, as the older libraries will used during the build, instead of the new ones, likely leading to an incorrectly build ICU. This is the proper behavior of rpath. 936 937## Platform Dependencies 938 939### Porting To A New Platform 940 941If you are using ICU's Makefiles to build ICU on a new platform, there are a few places where you will need to add or modify some files. If you need more help, you can always ask the [icu-support mailing list](http://site.icu-project.org/contacts). Once you have finished porting ICU to a new platform, it is recommended that you contribute your changes back to ICU via the icu-support mailing list. This will make it easier for everyone to benefit from your work. 942 943#### Data For a New Platform 944 945For some people, it may not be necessary for completely build ICU. Most of the makefiles and build targets are for tools that are used for building ICU's data, and an application's data (when an application uses ICU resource bundles for its data). 946 947Data files can be built on a different platform when both platforms share the same endianness and the same charset family. This assertion does not include platform dependent DLLs/shared/static libraries. For details see the User Guide [ICU Data](https://unicode-org.github.io/icu/userguide/icudata) chapter. 948 949ICU 3.6 removes the requirement that ICU be completely built in the native operating environment. It adds the icupkg tool which can be run on any platform to turn binary ICU data files from any one of the three formats into any one of the other data formats. This allows a application to use ICU data built anywhere to be used for any other target platform. 950 951**WARNING!** Building ICU without running the tests is not recommended. The tests verify that ICU is safe to use. It is recommended that you try to completely port and test ICU before using the libraries for your own application. 952 953#### Adapting Makefiles For a New Platform 954 955Try to follow the build steps from the [UNIX](#how-to-build-and-install-on-unix) build instructions. If the configure script fails, then you will need to modify some files. Here are the usual steps for porting to a new platform: 956 9571. Create an mh file in `<ICU>/source/config/`. You can use mh-linux or a similar mh file as your base configuration. 9582. Modify `<ICU>/source/aclocal.m4` to recognize your platform's mh file. 9593. Modify `<ICU>/source/configure.in` to properly set your **platform** C Macro define. 9604. Run [autoconf](http://www.gnu.org/software/autoconf/) in `<ICU>/source/` without any options. The autoconf tool is standard on most Linux systems. 9615. If you have any optimization options that you want to normally use, you can modify `<ICU>/source/runConfigureICU` to specify those options for your platform. 9626. Build and test ICU on your platform. It is very important that you run the tests. If you don't run the tests, there is no guarentee that you have properly ported ICU. 963 964### Platform Dependent Implementations 965 966The platform dependencies have been mostly isolated into the following files in the common library. This information can be useful if you are porting ICU to a new platform. 967 968* **unicode/platform.h.in** (autoconf'ed platforms) 969 **unicode/p_XXXX_.h** (others: pwin32.h, ppalmos.h, ..): Platform-dependent typedefs and defines: 970 * Generic types like `UBool`, `int8_t`, `int16_t`, `int32_t`, `int64_t`, `uint64_t` etc. 971 * `U_EXPORT` and `U_IMPORT` for specifying dynamic library import and export 972 * String handling support for the `char16_t` and `wchar_t` types. 973* **unicode/putil.h, putil.c**: platform-dependent implementations of various functions that are platform dependent: 974 * `uprv_isNaN`, `uprv_isInfinite`, `uprv_getNaN` and `uprv_getInfinity` for handling special floating point values. 975 * `uprv_tzset`, `uprv_timezone`, `uprv_tzname` and `time` for getting platform specific time and time zone information. 976 * `u_getDataDirectory` for getting the default data directory. 977 * `uprv_getDefaultLocaleID` for getting the default locale setting. 978 * `uprv_getDefaultCodepage` for getting the default codepage encoding. 979* **umutex.h, umutex.c**: Code for doing synchronization in multithreaded applications. If you wish to use International Components for Unicode in a multithreaded application, you must provide a synchronization primitive that the classes can use to protect their global data against simultaneous modifications. We already supply working implementations for many platforms that ICU builds on. 980* **umapfile.h, umapfile.c**: functions for mapping or otherwise reading or loading files into memory. All access by ICU to data from files makes use of these functions. 981* Using platform specific `#ifdef` macros are highly discouraged outside of the scope of these files. When the source code gets updated in the future, these `#ifdef`'s can cause testing problems for your platform. 982 983* * * 984 985Copyright © 2016 and later: Unicode, Inc. and others. License & terms of use: [http://www.unicode.org/copyright.html](http://www.unicode.org/copyright.html) 986Copyright © 1997-2016 International Business Machines Corporation and others. All Rights Reserved. 987