How to support C++ in a new OS

[ryx]

I want to get C++ support in my new operating system.
But I do not have much idea how to achieve it.
Could someone give me some guidance?
What functionality does my OS need to support? Now it has a C library, but is not compatible with Linux system call or posix API.
Does gcc have some hard dependency on some C library or system call when it compile c++ program or provide the runtime support?

Thanks a lot.

[MiiNiPaa]

I suggest to start reading from item 12 here: https://gcc.gnu.org/onlinedocs/gcc-2.95.3/gcc.html

http://stackoverflow.com/questions/6245481/porting-gcc-to-new-architectures

[ryx]

I am not trying to port gcc. I will still use gcc to compile my system in Linux.
But I want that the compiled binary can run on my OS.
It seems that gcc will put some its internal libraries in the final binary when compile C++ program, and those libraries have dependency on Linux or C library.
I do not know if this is true. And if it is true, how can I avoid or solve this problem?

Thanks a lot.

[MiiNiPaa]

those libraries have dependency on Linux or C library.

It is actually has dependencies on target platform (OS).
So you will have to implement runtime C and C++ libraries for your OS and make gcc link to it. And, of course, implement standard library itself, so it would use your own runtime library.

[ryx]

Thank you very much for your help.
But I don't know exactly which library is used by gcc, maybe libgcc or libsupc++?
And how can I tell gcc link to my library instead of its own?

[MiiNiPaa]

I don't know exactly which library is used by gcc,

https://gcc.gnu.org/onlinedocs/gcc/Standard-Libraries.html
glibc for C, libstdc++ for C++

And how can I tell gcc link to my library instead of its own?

You compile files with g++, then link it with ld, specifying your libraries. You might need to use -nostdlib switch to avoid automatic inclusion of system libraries, but you are better to read GCC specs for that.