静态链接是在编译时将链接的内容复制到主二进制文件中并变成单个二进制文件的过程。

缺点:

编译时间更长 输出二进制更大

动态链接是在运行时加载链接内容的过程。这项技术允许:

升级链接二进制文件而不重新编译主二进制文件，增加ABI稳定性[关于] 是否有单个共享副本

缺点:

开始时间较慢(应复制链接内容) 链接器错误在运行时抛出

[iOS静态vs动态框架]

1/我曾经参与过一个项目，其中动态链接和静态链接是基准测试，差异并没有小到可以切换到动态链接(我没有参与测试，我只知道结论)

2/ Dynamic linking is often associated with PIC (Position Independent Code, code which doesn't need to be modified depending on the address at which it is loaded). Depending on the architecture PIC may bring another slowdown but is needed in order to get benefit of sharing a dynamically linked library between two executable (and even two process of the same executable if the OS use randomization of load address as a security measure). I'm not sure that all OS allow to separate the two concepts, but Solaris and Linux do and ISTR that HP-UX does as well.

3/我在其他项目中使用了动态链接的“简单补丁”功能。但是这个“简单补丁”使得小补丁的发布更加容易，而复杂补丁的发布则成为版本控制的噩梦。因为错误的版本是token，我们经常不得不推送所有内容，并在客户站点跟踪问题。

我的结论是，我使用静态链接除外:

比如依赖于动态链接的插件 当共享是重要的(大型库被多个进程同时使用，如C/ c++运行时，GUI库，…它们通常是独立管理的，ABI对此有严格的定义)

如果有人想使用“简单的补丁”，我认为库必须像上面的大库一样管理:它们必须几乎独立，具有定义好的ABI，不能被修复更改。

在大量且越来越多的系统中，极端的静态链接可以对应用程序和系统性能产生巨大的积极影响。

我指的是通常所说的“嵌入式系统”，其中许多现在越来越多地使用通用操作系统，这些系统被用于所有可以想象到的事情。

An extremely common example are devices using GNU/Linux systems using Busybox. I've taken this to the extreme with NetBSD by building a bootable i386 (32-bit) system image that includes both a kernel and its root filesystem, the latter which contains a single static-linked (by crunchgen) binary with hard-links to all programs that itself contains all (well at last count 274) of the standard full-feature system programs (most except the toolchain), and it is less than 20 megabytes in size (and probably runs very comfortably in a system with only 64MB of memory (even with the root filesystem uncompressed and entirely in RAM), though I've been unable to find one so small to test it on).

It has been mentioned in earlier posts that the start-up time of a static-linked binaries is faster (and it can be a lot faster), but that is only part of the picture, especially when all object code is linked into the same file, and even more especially when the operating system supports demand paging of code direct from the executable file. In this ideal scenario the startup time of programs is literally negligible since almost all pages of code will already be in memory and be in use by the shell (and and init any other background processes that might be running), even if the requested program has not ever been run since boot since perhaps only one page of memory need be loaded to fulfill the runtime requirements of the program.

However that's still not the whole story. I also usually build and use the NetBSD operating system installs for my full development systems by static-linking all binaries. Even though this takes a tremendous amount more disk space (~6.6GB total for x86_64 with everything, including toolchain and X11 static-linked) (especially if one keeps full debug symbol tables available for all programs another ~2.5GB), the result still runs faster overall, and for some tasks even uses less memory than a typical dynamic-linked system that purports to share library code pages. Disk is cheap (even fast disk), and memory to cache frequently used disk files is also relatively cheap, but CPU cycles really are not, and paying the ld.so startup cost for every process that starts every time it starts will take hours and hours of CPU cycles away from tasks which require starting many processes, especially when the same programs are used over and over, such as compilers on a development system. Static-linked toolchain programs can reduce whole-OS multi-architecture build times for my systems by hours. I have yet to build the toolchain into my single crunchgen'ed binary, but I suspect when I do there will be more hours of build time saved because of the win for the CPU cache.

我同意dnmckee提到的观点，另外:

静态链接的应用程序可能更容易部署，因为很少或没有额外的文件依赖项(.dll / .so)，当它们丢失或安装在错误的位置时，可能会导致问题。

动态链接的最佳示例是库依赖于所使用的硬件。在古代，C数学库是动态的，这样每个平台都可以使用所有的处理器功能来优化它。

一个更好的例子可能是OpenGL。OpenGl是一个由AMD和NVidia实现的不同的API。你不能在AMD卡上使用NVidia实现，因为硬件是不同的。因此，你不能静态地将OpenGL链接到你的程序中。这里使用了动态链接，以便为所有平台优化API。

1)基于这样一个事实，即调用DLL函数总是使用额外的间接跳转。如今，这通常可以忽略不计。在DLL内部，i386 CPU上有一些更多的开销，因为它们不能生成与位置无关的代码。在amd64上，跳转可以相对于程序计数器，因此这是一个巨大的改进。

2)这是正确的。通过分析引导的优化，您通常可以获得大约10- 15%的性能。既然CPU速度已经达到极限，那么这样做可能是值得的。

我想补充的是:(3)链接器可以将函数安排在一个更有效的缓存分组中，从而将昂贵的缓存级别的失败最小化。它还可能特别影响应用程序的启动时间(基于我在Sun c++编译器中看到的结果)

不要忘记，使用dll不能执行死代码消除。根据语言的不同，DLL代码也可能不是最佳的。虚函数总是虚函数，因为编译器不知道客户端是否正在覆盖它。

由于这些原因，如果不需要dll，那么就使用静态编译。

编辑(通过用户下划线回答注释)

这里有一个关于职位独立代码问题的很好的资源http://eli.thegreenplace.net/2011/11/03/position-independent-code-pic-in-shared-libraries/

正如所解释的，x86除了15位跳转范围之外没有其他的AFAIK，也没有无条件跳转和调用。这就是为什么函数(来自生成器)超过32K一直是一个问题，需要嵌入蹦床。

But on popular x86 OS like Linux you do not need to care if the .so/DLL file is not generated with the gcc switch -fpic (which enforces the use of the indirect jump tables). Because if you don't, the code is just fixed like a normal linker would relocate it. But while doing this it makes the code segment non shareable and it would need a full mapping of the code from disk into memory and touching it all before it can be used (emptying most of the caches, hitting TLBs) etc. There was a time when this was considered slow.

这样你就没有任何收益了。

我不记得什么操作系统(Solaris或FreeBSD)给我的Unix构建系统的问题，因为我只是没有这样做，不知道为什么它崩溃，直到我应用-fPIC到gcc。