Mark assembly routines that don't need to be exported as hidden

native_client/src/trusted/service_runtime/nacl_config.h

 /*
  * Copyright 2008, 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.
@@ skipping 102 matching lines @@
  * NACL_TRAMPOLINE_END gives the address of the first byte after the
  * trampolines.
  */
 #define NACL_NULL_REGION_SHIFT  16
 #define NACL_TRAMPOLINE_START   (1 << NACL_NULL_REGION_SHIFT)
 #define NACL_TRAMPOLINE_SHIFT   16
 #define NACL_TRAMPOLINE_SIZE    (1 << NACL_TRAMPOLINE_SHIFT)
 #define NACL_TRAMPOLINE_END     (NACL_TRAMPOLINE_START + NACL_TRAMPOLINE_SIZE)
 /*
  * macros to provide uniform access to identifiers from assembly due
- * to different C -> asm name mangling convention
+ * to different C -> asm name mangling conventions and other platform-specific
+ * requirements
  */
 #if NACL_WINDOWS || NACL_OSX
 # define IDENTIFIER(n)  _##n
 #else /* Linux */
 # define IDENTIFIER(n)  n
 #endif
 
+#if NACL_OSX
+# define HIDDEN(n)  .private_extern IDENTIFIER(n)
+#elif NACL_LINUX
+# define HIDDEN(n)  .hidden IDENTIFIER(n)
+#else /* Windows */
+/* On Windows, symbols are hidden by default. */
+# define HIDDEN(n)
+#endif
+
 #if NACL_ARCH(NACL_BUILD_ARCH) == NACL_x86
 
 #if NACL_BUILD_SUBARCH == 32
 #define NACL_USERRET_FIX  0x8
 #elif NACL_BUILD_SUBARCH == 64
 #define NACL_USERRET_FIX  0xc
 #else /* NACL_BUILD_SUBARCH */
 #error Unknown platform!
 #endif /* NACL_BUILD_SUBARCH */
 
 #elif NACL_ARCH(NACL_BUILD_ARCH) == NACL_arm
 
 #define NACL_HALT         mov pc, #0
 #define NACL_CF_MASK      0xF000000F /* assumes 16-byte bundles */
 #define NACL_USERRET_FIX  0x4
 
 #else /* NACL_ARCH(NACL_BUILD_ARCH) */
 
 #error Unknown platform!
 
 #endif /* NACL_ARCH(NACL_BUILD_ARCH) */
 
 #define NACL_SYSARGS_FIX  NACL_USERRET_FIX + 0x4
 
 #endif  /* NATIVE_CLIENT_SERVICE_RUNTIME_NACL_CONFIG_H_ */