conflicting types for 'wchar_t'

最新推荐文章于 2025-04-19 10:21:16 发布

最新推荐文章于 2025-04-19 10:21:16 发布 · 169 阅读

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#移动开发

本文介绍了Android NDK中wchar_t类型的支持情况。针对不同API级别，wchar_t的大小及可用性有所不同。对于API级别9及以上，wchar_t大小为4字节，并提供了大部分宽字符函数；而对于更早的API级别，wchar_t大小为1字节且宽字符函数不可用。

/host/android-ndk-r7/mytoolchain/bin/../sysroot/usr/include/wchar.h:35: error: conflicting types for 'wchar_t'
/host/android-ndk-r7/mytoolchain/bin/../lib/gcc/arm-linux-androideabi/4.4.3/include/stddef.h:323: note: previous declaration of 'wchar_t' was here

Android NDK Dev Guide(from NDK)

USING THE ANDROID TOOLCHAIN AS A STANDALONE COMPILER

5.2/ wchar_t support:
- - - - - - - - - - -

As documented, the Android platform did not really support wchar_t until
Android 2.3. What this means in practical terms is that:

  - If you target platform android-9 or higher, the size of wchar_t is
    4 bytes, and most wide-char functions are available in the C library
    (with the exception of multi-byte encoding/decoding functions and
     wsprintf/wsscanf).

  - If you target any prior API level, the size of wchar_t will be 1 byte
    and none of the wide-char functions will work anyway.

We recommend any developer to get rid of any dependencies on the wchar_t type
and switch to better representations. The support provided in Android is only
there to help you migrate existing code.