linux: unexport as many symbols as possible

base/icu38_o3d.scons

 # Copyright 2009, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 379 matching lines @@
 
 def MakeObject(env, source, extra_defines):
   base, ext = os.path.splitext(source)
   return env.ComponentObject(base, '$ICU38_DIR/' + source,
                              CPPDEFINES = env['CPPDEFINES'] + extra_defines)
 
 
 
 if CombinedLib:
 
+  if env.Bit('linux'):
+    # U_STATIC_IMPLEMENTATION gets overridden by U_COMBINED_IMPLEMENTATION,
+    # which on linux causes all the symbols to be exported from the shared
+    # library, conflicting with the browser's definition if it uses icu as well
+    # (e.g.  Chrome).
+    combined_flag = []
+  else:
+    combined_flag = ['U_COMBINED_IMPLEMENTATION']
   # These empirically fail to build when U_COMMON_IMPLEMENTATION
   # isn't defined in addition to U_COMBINED_IMPLEMENTATION.  Remove
   # them from the source file list and re-append them with Nodes
   # for custom-built object files with both defined.
 
   need_common_implementation = [
       'source/common/ubidi.c',
       'source/common/ubidiln.c',
   ]
 
   objects = []
   for n in need_common_implementation:
     common_input_files.remove(n)
-    o = MakeObject(env, n, ['U_COMMON_IMPLEMENTATION',
-                            'U_COMBINED_IMPLEMENTATION'])
+    o = MakeObject(env, n, ['U_COMMON_IMPLEMENTATION'] + combined_flag)
     objects.append(o)
 
   sources = common_input_files + i18n_input_files + stubdata_input_files
-  objects += [MakeObject(env, n, ['U_COMBINED_IMPLEMENTATION'])
-              for n in sources]
+  objects += [MakeObject(env, n, combined_flag) for n in sources]
 
   icu_lib = env.ComponentLibrary('icu', objects);
 
 else:
 
   common_objects = [MakeObject(env, n, ['U_COMMON_IMPLEMENTATION'])
                     for n in common_input_files]
   icu_lib = env.ComponentLibrary('icuuc', common_objects)
 
   i18n_objects = [MakeObject(env, n, ['U_I18N_IMPLEMENTATION'])
@@ skipping 48 matching lines @@
   icu_data = None
 
   # The ICU library isn't useful without the data properly installed.
   if env.Bit('windows'):
     icu_data = env.Replicate('$ARTIFACTS_DIR', 'icudt38.dll')
   else:
     icu_data = env.Replicate('$ARTIFACTS_DIR',
                              '$ICU38_DIR/source/data/in/icudt38l.dat')
 
   env.Requires(icu_lib, icu_data)