How to build a DLL from the command line in Windows using MSVC

Question

I've been doing C for about 20 years but I've never built a DLL; I've always prefered to statically link.

I use the command line - cl.exe, etc - and gnumake makefiles, to build my Windows applications.

I now want to build a DLL and I'm confused.

Ultimately, I will end up with both a .lib and a .dll. The .lib contains stub code which at run time loads the DLL and uses the code therein.

I've been looking at the command lines for lib and link and it is not apparent to me exactly what is supposed to be done, to produce this output.

So I have some questions;

Does cl need any additional arguments, to indicate it is compiling for a DLL? (I know the DLL exported prototypes need __declspec(dllexport)).

I know link needs /dll as an argument.

Will I run lib and link, to produce the .lib and .dll respectively, or will link produce both?

What else do I need to know?

Answer 1

On the command line use:

cl.exe /LD <files-to-compile>

or, if you prefer the more verbose & explicit version:

cl.exe /D_USRDLL /D_WINDLL <files-to-compile> <files-to-link> /link /DLL /OUT:<desired-dll-name>.dll

Answer 2

Simlar to Ebow Halm's answer, but using a .def file for listing the exported functions and newer command line arguments:

"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\vcvars32.bat" && cl /O2 /Iall /Iyour /Iincludes /D_USRDLL /D_WINDLL /DOTHER_DEFINES <libs> <source files> /LD /Fe<dll name> /link /DEF:<def name>.def

References:

• https://msdn.microsoft.com/en-us/library/34c30xs1.aspx
• https://msdn.microsoft.com/en-us/library/19z1t1wy.aspx

Answer 3

Turns out it happens automatically.

If you have exported functions (eg /export, __declspec(dllexport), etc) the linker will automatically generate the .lib file (you do of course need /dll on the linker command line).

Answer 4

Does cl need any additional arguments, to indicate it is compiling for a DLL? (I know the DLL exported prototypes need __declspec(dllexport)).

Not since Win3x went away, now you just just need either __declspec(dllexport) or a .DEF file which defines the names of the symbols you want exported. a .def file allows you to export symbols with modified names, so it can still be useful for special cases.

I know link needs /dll as an argument.

Yep.

Will I run lib and link, to produce the .lib and .dll respectively, or will link produce both?

lib is used only to create static libraries (or to add .objs to your implib) Link will produce both a .dll and an import .lib for it.

Answer 5

最简单的查找方法是创建一个MSVC项目，在其中您可以随意设置所有内容，然后启用构建日志记录，进行构建并分析所有命令及其参数的构建日志。