Cleanup CMakeLists.txt

There were a few problems that needed to be addressed:

 - Our detection logic around testing if ICU supported a feature was
   still checking for C++ stuff instead of the coresponding C
   code (which we ended up using).

 - There was some cleanup we could do now that the OSX and other Unix
   builds were split apart

2 files changed, 27 insertions, 20 deletions

diff --git a/src/corefx/System.Globalization.Native/CMakeLists.txt b/src/corefx/System.Globalization.Native/CMakeLists.txt
index a4e232d4b9..08d35a0053 100644
--- a/src/corefx/System.Globalization.Native/CMakeLists.txt
+++ b/src/corefx/System.Globalization.Native/CMakeLists.txt
@@ -6,45 +6,49 @@ set(CMAKE_INCLUDE_CURRENT_DIR ON)
 add_definitions(-DPIC=1)
 add_definitions(-DBIT64=1)
 
-set(ICU_HOMEBREW_LIB_PATH "/usr/local/opt/icu4c/lib")
 set(ICU_HOMEBREW_INC_PATH "/usr/local/opt/icu4c/include")
 
+find_path(UTYPES_H "unicode/utypes.h" PATHS ${ICU_HOMEBREW_INC_PATH})
+if(UTYPES_H STREQUAL UTYPES_H-NOTFOUND)
+    message(FATAL_ERROR "Cannont find utypes.h, try installing libicu-dev (or the appropriate package for your platform)")
+    return()
+endif()
+
 if(NOT CLR_CMAKE_PLATFORM_DARWIN)
-    find_library(ICUUC NAMES icuuc PATHS ${ICU_HOMEBREW_LIB_PATH})
+    find_library(ICUUC icuuc)
     if(ICUUC STREQUAL ICUUC-NOTFOUND)
         message(FATAL_ERROR "Cannot find libicuuc, try installing libicu-dev (or the appropriate package for your platform)")
         return()
     endif()
 
-    find_library(ICUI18N NAMES icui18n PATHS ${ICU_HOMEBREW_LIB_PATH})
+    find_library(ICUI18N icui18n)
         if(ICUI18N STREQUAL ICUI18N-NOTFOUND)
         message(FATAL_ERROR "Cannot find libicui18n, try installing libicu-dev (or the appropriate package for your platform)")
         return()
     endif()
 
+    set(CMAKE_REQUIRED_INCLUDES ${ICU_HOMEBREW_INC_PATH})
+    CHECK_CXX_SOURCE_COMPILES("
+     #include <unicode/udat.h>
+     int main() { UDateFormatSymbolType e = UDAT_STANDALONE_SHORTER_WEEKDAYS; }
+    " HAVE_UDAT_STANDALONE_SHORTER_WEEKDAYS)
+
+    if(HAVE_UDAT_STANDALONE_SHORTER_WEEKDAYS)
+        add_definitions(-DHAVE_UDAT_STANDALONE_SHORTER_WEEKDAYS=1)
+    endif(HAVE_UDAT_STANDALONE_SHORTER_WEEKDAYS)
+
 else()
-    find_library(ICUCORE NAMES icucore)
+
+    find_library(ICUCORE icucore)
     if(ICUI18N STREQUAL ICUCORE-NOTFOUND)
         message(FATAL_ERROR "Cannot find libicucore, skipping build for System.Globalization.Native. .NET globalization is not expected to function.")
         return()
     endif()
-endif()
-
-find_path(UTYPES_H "unicode/utypes.h" PATHS ${ICU_HOMEBREW_INC_PATH})
-if(UTYPES_H STREQUAL UTYPES_H-NOTFOUND)
-    message(FATAL_ERROR "Cannont find utypes.h, try installing libicu-dev (or the appropriate package for your platform)")
-    return()
-endif()
 
-set(CMAKE_REQUIRED_INCLUDES ${ICU_HOMEBREW_INC_PATH})
-CHECK_CXX_SOURCE_COMPILES("
- #include <unicode/dtfmtsym.h>
- int main() { DateFormatSymbols::DtWidthType e = DateFormatSymbols::DtWidthType::SHORT; }
-" HAVE_DTWIDTHTYPE_SHORT) 
+    # libicucore supports UDAT_STANDALONE_SHORTER_WEEKDAYS
+    add_definitions(-DHAVE_UDAT_STANDALONE_SHORTER_WEEKDAYS=1)
 
-if(HAVE_DTWIDTHTYPE_SHORT)
-    add_definitions(-DHAVE_DTWIDTHTYPE_SHORT=1)
-endif(HAVE_DTWIDTHTYPE_SHORT)
+endif()
 
 add_compile_options(-fPIC)
 
diff --git a/src/corefx/System.Globalization.Native/calendarData.cpp b/src/corefx/System.Globalization.Native/calendarData.cpp
index aba9e7c8fb..c18bc9de8e 100644
--- a/src/corefx/System.Globalization.Native/calendarData.cpp
+++ b/src/corefx/System.Globalization.Native/calendarData.cpp
@@ -576,7 +576,10 @@ extern "C" int32_t EnumCalendarInfo(EnumCalendarInfoCallback callback,
         case AbbrevMonthNames:
             return EnumSymbols(locale, calendarId, UDAT_STANDALONE_SHORT_MONTHS, 0, callback, context);
         case SuperShortDayNames:
-#ifdef HAVE_DTWIDTHTYPE_SHORT
+            // UDAT_STANDALONE_SHORTER_WEEKDAYS was added in ICU 51, and CentOS 7 currently uses ICU 50.
+            // fallback to UDAT_STANDALONE_NARROW_WEEKDAYS in that case.
+
+#ifdef HAVE_UDAT_STANDALONE_SHORTER_WEEKDAYS
             return EnumSymbols(locale, calendarId, UDAT_STANDALONE_SHORTER_WEEKDAYS, 1, callback, context);
 #else
             return EnumSymbols(locale, calendarId, UDAT_STANDALONE_NARROW_WEEKDAYS, 1, callback, context);