Additional Update Guidelines for ICU

As a reminder, these are guidelines. The version you update to might make some of these steps obsolete, so make sure you understand what they do and why they're necessary.

Generate `icudtXXl.dat.xz` Artifact

The following commands should be executed on Linux.

Create and set up the build directory

mkdir build
cp -rp icuSources/* build/
cd build
chmod +x runConfigureICU && chmod +x configure

Patch tools/icuinfo/icuinfo.cpp to remove references to Mach components.

Example patch for tools/icuinfo/icuinfo.cpp:

--- ../icuSources/tools/icuinfo/icuinfo.cpp	2019-09-07 22:44:27.000000000 -0400
+++ tools/icuinfo/icuinfo.cpp	2020-07-01 10:21:00.796333708 -0400
@@ -308,7 +308,9 @@

 // Apple addition
 #include <unistd.h>
+#if 0
 #include <mach/mach_time.h>
+#endif
 #include <unicode/ustring.h>
 #include <unicode/udat.h>
 enum { kUCharsOutMax = 128, kBytesOutMax = 256 };
@@ -319,15 +321,18 @@
     static const UDate udatTry1 = 1290714600000.0; // 2010 Nov. 25 (Thurs) 11:50:00 AM PT
     static const UDate udatTry2 = 1451736016000.0; // 2016 Jan. 02  ...
     int remaining = 2;
+#if 0
     mach_timebase_info_data_t info;
     mach_timebase_info(&info);
+#endif
     while (remaining-- > 0) {
+#if 0
         uint64_t start, durationOpen, durationUse1, durationUse2;
         UDateFormat *udatfmt;
         int32_t datlen1, datlen2;
         UChar outUChars[kUCharsOutMax];
         UErrorCode status = U_ZERO_ERROR;
-
+
         start = mach_absolute_time();
         udatfmt = udat_open(UDAT_MEDIUM, UDAT_FULL, locale, tzName, -1, NULL, 0, &status);
         durationOpen = ((mach_absolute_time() - start) * info.numer)/info.denom;
@@ -347,8 +352,11 @@
             }
             udat_close(udatfmt);
         } else {
+#endif
             printf("first time %d udat_open failed\n", remaining);
+#if 0
         }
+#endif
     }
 }

Set up the build flags and execute runConfigureICU.

APPLE_INTERNAL_DIR="/AppleInternal" \
LANG="en_US.utf8" \
CPPFLAGS="-DU_DISABLE_RENAMING=1"  \
CFLAGS="-DU_SHOW_CPLUSPLUS_API=1 -DU_SHOW_INTERNAL_API=1 -DICU_DATA_DIR=\"\\\"/usr/local/share/icu/\\\"\" -DICU_DATA_DIR_PREFIX_ENV_VAR=\"\\\"APPLE_FRAMEWORKS_ROOT\\\"\" -m64 -g -Os -fno-exceptions -fvisibility=hidden" \
CXXFLAGS="-std=c++11 -DU_SHOW_CPLUSPLUS_API=1 -DU_SHOW_INTERNAL_API=1 -DICU_DATA_DIR=\"\\\"/usr/local/share/icu/\\\"\" -DICU_DATA_DIR_PREFIX_ENV_VAR=\"\\\"APPLE_FRAMEWORKS_ROOT\\\"\" -m64 -g -Os -fno-exceptions -fvisibility=hidden -fvisibility-inlines-hidden" \
DYLD_LIBRARY_PATH="/usr/local/lib" \
./runConfigureICU Linux --disable-renaming --disable-extras --disable-layout --disable-samples --with-data-packaging=archive --prefix=/usr/local --with-library-bits=64

In a new terminal window, set up the build flags and run make

APPLE_INTERNAL_DIR="/AppleInternal" \
LANG="en_US.utf8" \
CFLAGS="-DU_SHOW_CPLUSPLUS_API=1 -DU_SHOW_INTERNAL_API=1 -DICU_DATA_DIR=\"\\\"/usr/local/share/icu/\\\"\" -DICU_DATA_DIR_PREFIX_ENV_VAR=\"\\\"APPLE_FRAMEWORKS_ROOT\\\"\" -m64 -g -Os -fno-exceptions -fvisibility=hidden" \
CXXFLAGS="-std=c++11 -DU_SHOW_CPLUSPLUS_API=1 -DU_SHOW_INTERNAL_API=1 -DICU_DATA_DIR=\"\\\"/usr/local/share/icu/\\\"\" -DICU_DATA_DIR_PREFIX_ENV_VAR=\"\\\"APPLE_FRAMEWORKS_ROOT\\\"\" -m64 -g -Os -fno-exceptions -fvisibility=hidden -fvisibility-inlines-hidden" \
DYLD_LIBRARY_PATH="/usr/local/lib" \
make

Save and compress the generated icudtXXl.dat artifact

The version number might not be the same as before. If that is the case, you will need to update the CMakeLists.txt as well to use the new icudtXXl.dat file.

# For this example, the version number provided is 64
mkdir ../icuSources/data/out
cp data/out/icudt64l.dat ../icuSources/data/out/icudt64l.dat
xz -z ../icuSources/data/out/icudt64l.dat

Remove the build folder

cd ..
rm -rf build