From 48124d170635f4abcd7440c5beeb6ea9878de32b Mon Sep 17 00:00:00 2001
From: Cyndy Ishida <cyndy_ishida@apple.com>
Date: Thu, 23 Jun 2022 06:50:39 -0700
Subject: [PATCH] ICU-22072 Update Darwin Specific Macros

* Update `U_PF_IPHONE` to be 0 when building for macOS/macCatalyst.
* add macro definition for `attribute((visibility("hidden")))` for cases
  where internal structs exist within exposed classes.
---
 icu4c/source/common/unicode/platform.h    | 10 +++++++++-
 icu4c/source/i18n/unicode/dtitvinf.h      |  2 +-
 icu4c/source/i18n/unicode/dtptngen.h      |  6 +++---
 icu4c/source/i18n/unicode/listformatter.h |  2 +-
 4 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/icu4c/source/common/unicode/platform.h b/icu4c/source/common/unicode/platform.h
index b7e514442ce..6d370efc31f 100644
--- a/icu4c/source/common/unicode/platform.h
+++ b/icu4c/source/common/unicode/platform.h
@@ -168,7 +168,7 @@
 #   define U_PLATFORM U_PF_LINUX
 #elif defined(__APPLE__) && defined(__MACH__)
 #   include <TargetConditionals.h>
-#   if defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE  /* variant of TARGET_OS_MAC */
+#   if (defined(TARGET_OS_IPHONE) && TARGET_OS_IPHONE) && (defined(TARGET_OS_MACCATALYST) && !TARGET_OS_MACCATALYST)   /* variant of TARGET_OS_MAC */
 #       define U_PLATFORM U_PF_IPHONE
 #   else
 #       define U_PLATFORM U_PF_DARWIN
@@ -847,6 +847,14 @@ namespace std {
 #   define U_IMPORT 
 #endif
 
+#ifdef U_HIDDEN
+    /* Use the predefined value. */
+#elif defined(__GNUC__)
+#   define U_HIDDEN __attribute__((visibility("hidden")))
+#else
+#   define U_HIDDEN 
+#endif
+
 /**
  * \def U_CALLCONV
  * Similar to U_CDECL_BEGIN/U_CDECL_END, this qualifier is necessary
diff --git a/icu4c/source/i18n/unicode/dtitvinf.h b/icu4c/source/i18n/unicode/dtitvinf.h
index b5afc064678..a1f4f426a1c 100644
--- a/icu4c/source/i18n/unicode/dtitvinf.h
+++ b/icu4c/source/i18n/unicode/dtitvinf.h
@@ -343,7 +343,7 @@ private:
     /**
      * Internal struct used to load resource bundle data.
      */
-    struct DateIntervalSink;
+    struct U_HIDDEN DateIntervalSink;
 
     /**
      * Following is for saving the interval patterns.
diff --git a/icu4c/source/i18n/unicode/dtptngen.h b/icu4c/source/i18n/unicode/dtptngen.h
index e70d1923c98..6d2351ffca8 100644
--- a/icu4c/source/i18n/unicode/dtptngen.h
+++ b/icu4c/source/i18n/unicode/dtptngen.h
@@ -658,9 +658,9 @@ private:
     static void U_CALLCONV loadAllowedHourFormatsData(UErrorCode &status);
     void getAllowedHourFormats(const Locale &locale, UErrorCode &status);
 
-    struct AppendItemFormatsSink;
-    struct AppendItemNamesSink;
-    struct AvailableFormatsSink;
+    struct U_HIDDEN AppendItemFormatsSink;
+    struct U_HIDDEN AppendItemNamesSink;
+    struct U_HIDDEN AvailableFormatsSink;
 } ;// end class DateTimePatternGenerator
 
 U_NAMESPACE_END
diff --git a/icu4c/source/i18n/unicode/listformatter.h b/icu4c/source/i18n/unicode/listformatter.h
index af94a9f2319..0277afd1671 100644
--- a/icu4c/source/i18n/unicode/listformatter.h
+++ b/icu4c/source/i18n/unicode/listformatter.h
@@ -268,7 +268,7 @@ class U_I18N_API ListFormatter : public UObject{
 
     static void initializeHash(UErrorCode& errorCode);
     static const ListFormatInternal* getListFormatInternal(const Locale& locale, const char *style, UErrorCode& errorCode);
-    struct ListPatternsSink;
+    struct U_HIDDEN ListPatternsSink;
     static ListFormatInternal* loadListFormatInternal(const Locale& locale, const char* style, UErrorCode& errorCode);
 
     ListFormatter() = delete;