Question

我在安装版本的libsasl2（Cyrus SASL）时遇到了一些麻烦。

特别是，似乎本地头文件和sasl_version报告版本2.1.26，但没有为全局函数sasl_client_done提供符号。

我很确定我应该有这个符号，因为：

它位于提供的sasl / sasl.h标题
cyrsus sasl NEWS文件列出“已实施的sasl_client_done（）/ sasl_server_done（）”作为2.1.24功能
在约塞米蒂以外的任何地方提供2.1.26

复制：

请注意下面的示例打印
- “impl：'Cyrus SASL'，版本：33619994，专业：2，未成年人：1，步骤：26”
示例在取消注释代码

未注释的代码在yosemite上产生链接错误

Undefined symbols for architecture x86_64:
  "_sasl_client_done", referenced from:
      _main in foo-072675.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

使用：

调用编译器

clang -Wall -Werror -lsasl2 -o foo foo.c -v

with clang -v of：

Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)
Target: x86_64-apple-darwin14.0.0
Thread model: posix
 "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang" -cc1 -triple x86_64-apple-macosx10.10.0 -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -main-file-name foo.c -mrelocation-model pic -pic-level 2 -mdisable-fp-elim -masm-verbose -munwind-tables -target-cpu core2 -target-linker-version 241.9 -v -resource-dir /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/6.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk -Wall -Werror -fdebug-compilation-dir /Users/jcarey/work -ferror-limit 19 -fmessage-length 0 -stack-protector 1 -mstackrealign -fblocks -fobjc-runtime=macosx-10.10.0 -fencode-extended-block-signature -fdiagnostics-show-option -vectorize-slp -o /var/folders/wq/jypwqgv976n0db5l5qxw900r0000gq/T/foo-92054e.o -x c foo.c
clang -cc1 version 6.0 based upon LLVM 3.5svn default target x86_64-apple-darwin14.0.0
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/local/include"
ignoring nonexistent directory "/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/Library/Frameworks"
#include "..." search starts here:
#include <...> search starts here:
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/6.0/include
 /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include
 /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/System/Library/Frameworks (framework directory)
End of search list.
 "/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ld" -demangle -dynamic -arch x86_64 -macosx_version_min 10.10.0 -syslibroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk -o foo -lsasl2 /var/folders/wq/jypwqgv976n0db5l5qxw900r0000gq/T/foo-92054e.o -lSystem /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/6.0/lib/darwin/libclang_rt.osx.a
Undefined symbols for architecture x86_64:
  "_sasl_client_done", referenced from:
      _main in foo-92054e.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

有问题的代码：

#include <sasl/sasl.h>
#include <stdio.h>
#include <stdint.h>

int main(int argc, char ** argv) {
    const char *impl;
    int version;
    uint32_t buf;
    uint16_t major;
    uint8_t minor;
    uint8_t step;

    sasl_version(&impl, &version);

    buf = version;

    major = buf >> 24;
    minor = (buf << 8) >> 24;
    step = (buf << 24) >> 24;

    printf("impl: '%s', version: %d, major: %d, minor: %d, step: %d\n", impl, version, major, minor, step);

    /*
    {
        int (* scd)(void);

        scd = &sasl_client_done;

        printf("sasl_client_done: %p\n", scd);
    }
    */

    return 0;
}

我认为cyrus sasl为Yosemite打包的方式有些麻烦（或许是使用Mavericks的符号列表？）。

Answer 1

感兴趣的是，我刚用10.10.4检查过，我看到符号现在在那里：

$ nm /usr/lib/libsasl2.dylib |grep sasl_client_done
000000000000724a T _sasl_client_done

示例代码现在工作正常（注释部分现在取消注释）。仍然返回相同的Cyrus SASL版本：

impl: 'Cyrus SASL', version: 33619994, major: 2, minor: 1, step: 26
sasl_client_done: 0x7fff8e3dc24a

在OSX Yosemite上是否破坏了libsasl2？缺少sasl_client_done

1 个答案: