如何编译用C编写的64位dll？ [英] How to compile a 64-bit dll written in C?

问题描述

我有一个Java程序，该程序利用一些本机函数调用来加快视频编码。它需要一个DLL，我将用C编写该DLL（我现在只有一个测试）。

I have a Java program which makes use of some native function calls to speed up video encoding. It requires a DLL, which I will write in C (I have just a test one right now).

当我使用 cl编译DLL时/ I java-path / include / java-path / include / win32 -DL -ML Main.c -FeTest.dll 它可以编译，但是得到了32位DLL。在互联网上进行了一些研究之后，我发现我需要一个64位DLL。

When I compile the DLL with cl /I "java-path/include" /"java-path/include/win32" -DL -ML Main.c -FeTest.dll it compiles, but I get a 32-bit DLL. After I did some research on the internet, I found out that I would need a 64-bit DLL instead.

经过更多研究，我发现这篇文章，这是唯一的一篇C语言（甚至很难找到C ++），但这仅在通过Visual Studio 2010进行编写/构建时才有效。我将Elipse用于Java，将CLion用于C，并通过开发人员命令提示符进行编译。所以这对我不起作用。如何将其重新编译为64位DLL？

After more research, I have found this post which is the only one for C (even C++ was hard to find), but this only works if you are writing/building via Visual Studio 2010. I am using Elipse for the Java, CLion for the C, and compiling via the "Developer Command Prompt." so this does not work for me. How might I recompile as a 64-bit DLL?

编辑：我正在使用随附的 cl.exe 使用Visual Studio 2017

I am using the cl.exe that comes with Visual Studio 2017

更新：我在下找到了64位的 cl.exe C：\Program Files（x86）\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.13.26128\bin\Hostx64\x64\cl.exe ，但是在运行它时，我收到一个错误，指出库机器类型（x86）与目标类型（x64）冲突。如何更改库计算机的类型？

UPDATE: I found the 64-bit cl.exe under C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\VC\Tools\MSVC\14.13.26128\bin\Hostx64\x64\cl.exe, however when running it, I get an error that the library machine type (x86) conflicts with the target type (x64). How do I change the library machine type?

推荐答案

正如我在[SO]：如何构建libjpeg 9b的DLL版本？ （@CristiFati的答案）（来自 1。准备地面部分的项目符号），有多种方法可以处理 VStudio 中的命令行构建。
我将重点放在 vcvarsall.bat 。有关 [MSDN]：设置路径和命令行构建的环境变量（ VStudio2017 链接的 VStudio2015 断开了）。
我准备了一个虚拟示例。

As I explained at the beginning of [SO]: How to build a DLL version of libjpeg 9b? (@CristiFati's answer) (bullets from 1. Prepare the ground section), there are different ways to deal with building from command line in VStudio.
I'm going to focus on vcvarsall.bat. More details on [MSDN]: Setting the Path and Environment Variables for Command-Line Builds (It's VStudio2015 as VStudio2017 link is broken).
I prepared a dummy example.

code.c ：

#include <stdio.h>
#include "jni.h"


__declspec(dllexport) int func() {
    JavaVMInitArgs args;
    printf("Pointer size: %lld bits\n", sizeof(void*) * 8);
    printf("JNI_GetDefaultJavaVMInitArgs returned: %d\n", JNI_GetDefaultJavaVMInitArgs(&args));
    return 0;
}

构建：

e:\Work\Dev\StackOverflow\q050164687>"c:\Install\x86\Microsoft\Visual Studio Community\2017\VC\Auxiliary\Build\vcvarsall.bat" amd64
**********************************************************************
** Visual Studio 2017 Developer Command Prompt v15.6.6
** Copyright (c) 2017 Microsoft Corporation
**********************************************************************
[vcvarsall.bat] Environment initialized for: 'x64'

e:\Work\Dev\StackOverflow\q050164687>dir /b
code.c

e:\Work\Dev\StackOverflow\q050164687>cl /nologo /LD /I"c:\Install\x64\Oracle\Java\jdk1.8.0_152\include" /I"c:\Install\x64\Oracle\Java\jdk1.8.0_152\include\win32" /DWIN64 /DWIN32 code.c /link /LIBPATH:"c:\Install\x64\Oracle\Java\jdk1.8.0_152\lib" /OUT:dummy.dll jvm.lib
code.c
   Creating library code.lib and object code.exp

e:\Work\Dev\StackOverflow\q050164687>dir /b
code.c
code.exp
code.lib
code.obj
dummy.dll

注释：

• 我的 vcvarsall 路径是自定义的，因为我安装了< C：\Install\x86\Microsoft\Visual Studio Community\2017 下的em> VStudio2017 。默认路径为 ％SystemDrive％\程序文件（x86）\Microsoft Visual Studio\2017\社区


• 运行 vcvarsall后，我不必指定 cl.exe （或 link.exe ）：
  
  
  
  
  • 完整路径
  
  
  • 构建选项（特定于体系结构，包括路径）
  
  
  • 我仍然必须指定它没有的内容知道（例如 Java 的东西）
  
  
  • My vcvarsall path is custom, because I installed VStudio2017 under "C:\Install\x86\Microsoft\Visual Studio Community\2017". Default path is "%SystemDrive%\Program Files (x86)\Microsoft Visual Studio\2017\Community"
  • After running vcvarsall, I don't have to specify to cl.exe (or link.exe):
    • The full path
    • Build options (architecture specific, including paths)
    • I still have to specify things that it doesn't know about (like Java stuff)

    
    

    e:\Work\Dev\StackOverflow\q050164687>set PATH=%PATH%;c:\Install\x64\Oracle\Java\jdk1.8.0_152\jre\bin\server
    
    e:\Work\Dev\StackOverflow\q050164687>"e:\Work\Dev\VEnvs\py35x64_test\Scripts\python.exe"
    Python 3.5.4 (v3.5.4:3f56838, Aug  8 2017, 02:17:05) [MSC v.1900 64 bit (AMD64)] on win32
    Type "help", "copyright", "credits" or "license" for more information.
    >>> import ctypes
    >>> dummy = ctypes.CDLL("dummy.dll")
    >>> dummy.func()
    Pointer size: 64 bits
    JNI_GetDefaultJavaVMInitArgs returned: -1
    0
    >>>
    

    
    

    这篇关于如何编译用C编写的64位dll？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！