c++ - g++命令中 ".map"文件有什么用？

Question

我正在构建一个 RPM，在构建过程中我发现以下命令用于构建 RPM 的一个共享对象。

g++ /*some compiler options*/ -O1 -Wl,--version-script abc.map -L<some paths> and the remaining command.

我不明白命令中“--version-script”选项和“abc.map”文件的用途。它能做什么？以下是“abc.map”文件的内容。

URE_1{
    global:
       _ZTI*; _ZTS*; # weak RTTI symbols for C++ exceptions
    /*some method names explicitly*/
    local:
     *;
}

我认为它与使“共享对象”文件中的符号可用有关，但我不确定。

Answer 1

I think its related to making availability of symbols in the "shared object" file but I'm not sure.

你是对的。

参见 3.9 VERSION Command :

The linker supports symbol versions when using ELF. Symbol versions are only useful when using shared libraries. The dynamic linker can use symbol versions to select a specific version of a function when it runs a program that may have been linked against an earlier version of the shared library.