-static-libstdc ++可以在g ++上使用，但不能在纯gcc上使用? [英] -static-libstdc++ works on g++ but not on pure gcc?

问题描述

作为参考，我正在使用MinGW(GCC 5.3).使用

For the reference I'm using MinGW (GCC 5.3). When compiling a file with

g++ file.cc -static-libstdc++

它静态链接C ++标准库(libstdc++)并生成1.9MB可执行文件.

it statically links the C++ standard lib (libstdc++) and produces a 1.9MB executable.

但是正在运行

gcc -lstdc++ -static-libstdc++ file.cc

它仍然动态链接到libstdc++-6.dll并生成34KB可执行文件.

it still dynamically links to libstdc++-6.dll and produces a 34KB executable.

为什么-static-libstdc++仅适用于g++，而不适用于纯gcc?

Why does -static-libstdc++ only work with g++ but not with pure gcc?

推荐答案

说:

-static-libstdc ++

-static-libstdc++

使用g ++程序链接C ++程序时，通常会自动链接 针对libstdc ++.如果libstdc ++可作为共享库使用，则-static 选项未使用，则此链接指向libstdc ++的共享版本. 通常没关系.不过，冻结版本有时会很有用 程序使用的libstdc ++不会一直到完全静态的链接. -static-libstdc ++选项指示g ++驱动程序静态链接libstdc ++， 不必静态链接其他库.

When the g++ program is used to link a C++ program, it normally automatically links against libstdc++. If libstdc++ is available as a shared library, and the -static option is not used, then this links against the shared version of libstdc++. That is normally fine. However, it is sometimes useful to freeze the version of libstdc++ used by the program without going all the way to a fully static link. The -static-libstdc++ option directs the g++ driver to link libstdc++ statically, without necessarily linking other libraries statically.

这清楚表明选项-static-libstdc++仅对 g++编译器驱动程序，而不是gcc或其他任何驱动程序.

This makes clear that the option -static-libstdc++ is meaningful only to the g++ compiler driver, not gcc or any other.

另一方面，选项-l<name>是有意义的，并且含义相同 所有GCC编译器驱动程序.在此基础上不足为奇:

On the other hand the option -l<name> is meaningful and means the same thing to all GCC compiler drivers. On that basis it is not surprising that:

gcc file.cc -lstdc++ -static-libstdc++

与以下含义相同:

gcc file.cc -lstdc++ 

然而，这种观察并不能真正说明为什么第一个 命令行动态链接libstdc++:-

However, that observation does not truly illuminate why the first of those commandlines dynamically links libstdc++:-

-static-libstdc++仅对g++有意义，因为仅g++链接 libstdc++自动.因此，仅对于g++才出现问题 自动链接的libstdc++是否为动态版本 或静态版本.动态版本是默认版本:-static-libstdc++ 坚持使用静态版本.

-static-libstdc++ is meaningful only to g++ because only g++ links libstdc++ automatically. So it is only for g++ that the question arises whether the automatically linked libstdc++ will be the dynamic version or the static version. The dynamic version is the default: -static-libstdc++ insists on the static version.

g++的 libstdc++自动链接 libstdc++的意思是:g++静默 将-lstdc++附加到您指定的 链接选项中(以及 还有很多其他用于C ++链接的样板).你可以揭示所有 通过请求详细链接(g++ ... -Wl,-v ...)来制作样板.

The automatic linking of libstdc++ by g++ means this: g++ silently appends -lstdc++ to whatever linkage options you specify (along with quite a lot of other boiler-plate for a C++ linkage). You can reveal all the boilerplate by requesting verbose linkage (g++ ... -Wl,-v ...).

本身，附加的-lstdc++将使链接器链接动态版本 根据其默认行为，为libstdc++的值.唯一的不同 -static-libstdc++是在-lstdc++否则会出现的地方 被悄悄地传递给链接器，这些选项:

By itself, the appended -lstdc++ will cause the linker to link the dynamic version of libstdc++, per its default behaviour. The only difference made by -static-libstdc++ is that in the place where -lstdc++ would otherwise be silently passed to the linker, the options:

-Bstatic -lstdc++ -Bdynamic

却无声地传递给它.这些告诉链接器:

are silently passed to it instead. These tell the linker:

• -Bstatic:除非另行通知，否则不要链接动态库
• -lstdc++:链接libstdc++
• -Bdynamic:链接动态库，直到另行通知.

• -Bstatic: Do not link dynamic libraries until further notice
• -lstdc++: Link libstdc++
• -Bdynamic: Link dynamic libraries until further notice.

您将了解如何在不使用libstdc++的情况下确保libstdc++的静态链接的安全性 消除了对其他任何库的链接的副作用.

You see how that works to secure the static linkage of libstdc++ without out side-effects on the linkage of any other library.

但是您还可以看到libstdc++的自动链接，无论 动态地或静态地，对链接没有追溯作用 您指定自己的所有库中的任何一个.

But you can also see that the automatic linkage of libstdc++, whether dynamically or statically, has no retroactive effect on the linkage of any libraries you have specified yourself.

因此，如果您的链接在任何样板之前已经包含-lstdc++ 选项由编译器驱动程序静默附加，然后将链接libstdc++ 与链接中该位置的任何-l<name>相同 顺序.并且，如果无声附加的样板选项导致-lstdc++ 稍后会在链接序列中重新出现，无论是单独出现还是与 环境:

Hence, if your linkage already includes -lstdc++ before any boiler-plate options are silently appended by the compiler driver, then libstdc++ will be linked in just the same way as any -l<name> at that position in the linkage sequence. And if silently appended boiler-plate options result in -lstdc++ reappearing later in the linkage sequence, whether by itself or with the surroundings:

-Bstatic -lstdc++ -Bdynamic

然后，以后的外观将只是 redundant ，因为该库具有 已经被链接.

then the later appearance will simply be redundant, because the library has already been linked.

因此，gcc并没有什么特别的结果:

So there is nothing peculiar about gcc that results in:

gcc file.cc -lstdc++ -static-libstdc++

生成其中libstdc++是动态链接的 程序.

producing a program in which libstdc++ is dynamically linked. So does

g++ file.cc -lstdc++ -static-libstdc++

或者实际上:

g++ file.cc -static-libstdc++ -lstdc++

因为生成的链接器命令行格式为:

because the generated linker commandline is of the form:

... file.o -lstdc++ ... -Bstatic -lstdc++ -Bdynamic ...

其中-Bstatic -lstdc++ -Bdynamic为时已晚，没有任何区别.

where -Bstatic -lstdc++ -Bdynamic is too late to make any difference.

签出:

file.cc

#include <iostream>

int main()
{
    std::cout << "Hello World" << std::endl;
    return 0;
}

正常编译和链接，并使用ldd检查动态依赖项:

Compile and link normally and inspect the dynamic dependencies with ldd:

$ g++ -o prog file.cc
$ ldd prog
linux-vdso.so.1 =>  (0x00007ffede76a000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007f42fa74c000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f42fa385000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f42fa07c000)
/lib64/ld-linux-x86-64.so.2 (0x0000558ab42bc000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007f42f9e65000)

libstdc++.so存在.

现在只使用-static-libstdc++:

$ g++ -o prog file.cc -static-libstdc++
$ ldd prog
linux-vdso.so.1 =>  (0x00007fff448d7000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fe5f7c71000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fe5f78aa000)
/lib64/ld-linux-x86-64.so.2 (0x0000556ebf272000)

libstdc++.so不存在.

最后是-static-libstdc++ -lstdc++:

$ g++ -o prog file.cc -static-libstdc++ -lstdc++
$ ldd prog
linux-vdso.so.1 =>  (0x00007ffd12de9000)
libstdc++.so.6 => /usr/lib/x86_64-linux-gnu/libstdc++.so.6 (0x00007fd5a1823000)
libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fd5a145c000)
libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007fd5a1153000)
/lib64/ld-linux-x86-64.so.2 (0x000055bbe31c3000)
libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fd5a0f3c000)

libstdc++.so又回来了.

(当然，这是Linux，但是在Windows上会发现相同的东西.)

(This is Linux, of course, but you'll find the same thing on Windows).

因此，无论您是使用g++还是gcc进行链接，其原因都是

So whether you drive your linkage with g++ or gcc, the reason that

{gcc|g++} file.cc -lstdc++ ...

将导致libstdc++被动态链接，仅仅是因为

will result in libstdc++ being dynamically linked is simply that

{gcc|g++} file.cc -lfoo ...

会导致libfoo动态链接，无论如何 什么是...，前提是...不包含选项-static.

will cause libfoo to be dynamically linked, if it can be, regardless of what ... is, provided only that ... does not contain the option -static.

这篇关于-static-libstdc ++可以在g ++上使用，但不能在纯gcc上使用?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！