error: implicit declaration of function 'posix_memalign' [-Werror=implicit-function-declaration]_implicit declaration of function ‘memalign’-优快云博客

本文链接：https://blog.youkuaiyun.com/yangxiao_xiang/article/details/50339503

在使用NDK版本Android-21编译的代码在Android 4.4.2及以下版本时，会遇到'posix_memalign'未定义的引用错误。为解决此问题，可以下载并修改NDK中API 17, 18, 19的libstdc++.h文件，或者在Android-19的arch-arm/usr/include下添加stdlib.h。" 136224369,11357560,技术预研规程与实施,"['软件研发', '项目管理', '流程规范', '技术预研']

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

采用NDK版本Android-21编译的文件在android-21以下版本(4.4.2)可能出现以下问题：

error: undefined reference to 'atof'

参考:https://code.google.com/p/android/issues/detail?id=77861

When i use NDK r10b build success

APP_ABI := armeabi-v7a-hard
APP_PLATFORM := android-19
but when use NDK r10c, platform targe android-21, compile ok, but run error: dlopen failed: cannot locate symbol "atof" referenced
APP_ABI := armeabi-v7a-hard
APP_PLATFORM := android-21

解决办法：

下载并修改NDK中API 17,18,19中的libstd.h文件

下载地址：unzip -v posix_memalign_decl_17_18_19.zip

Ubuntu下操作方法：
unzip -v posix_memalign_decl_17_18_19.zip 


Archive:  posix_memalign_decl_17_18_19.zip
 Length   Method    Size  Cmpr    Date    Time   CRC-32   Name
--------  ------  ------- ---- ---------- ----- --------  ----
    5420  Defl:N     1993  63% 2014-10-22 10:38 85fa17d2  platforms/android-17/arch-arm/usr/include/stdlib.h
    5420  Defl:N     1993  63% 2014-10-22 10:38 85fa17d2  platforms/android-17/arch-mips/usr/include/stdlib.h
    5420  Defl:N     1993  63% 2014-10-22 10:38 85fa17d2  platforms/android-17/arch-x86/usr/include/stdlib.h
    5420  Defl:N     1993  63% 2014-10-22 10:38 85fa17d2  platforms/android-18/arch-arm/usr/include/stdlib.h
    5420  Defl:N     1993  63% 2014-10-22 10:38 85fa17d2  platforms/android-18/arch-mips/usr/include/stdlib.h
    5420  Defl:N     1993  63% 2014-10-22 10:38 85fa17d2  platforms/android-18/arch-x86/usr/include/stdlib.h
    5420  Defl:N     1993  63% 2014-10-22 10:38 85fa17d2  platforms/android-19/arch-arm/usr/include/stdlib.h
    5420  Defl:N     1993  63% 2014-10-22 10:38 85fa17d2  platforms/android-19/arch-mips/usr/include/stdlib.h
    5420  Defl:N     1993  63% 2014-10-22 10:38 85fa17d2  platforms/android-19/arch-x86/usr/include/stdlib.h
--------          -------  ---                            -------
   48780            17937  63%                            9 files

此外，还可以在platform/android-19/arch-arm/usr/include下将stdlib.h文件添加

<span style="font-size:18px;">extern int posix_memalign(void **memptr, size_t alignment, size_t size);</span>