How to compile assembly generated by rustc?

help
1

Hello! Is it possible to emit assembly in rustc and then compile it with GNU Assembler? I tried to do so, but I got these linker errors when I ran as and then ld:

ld: warning: cannot find entry symbol _start; defaulting to 0000000000401000
ld: a.o: in function `std::rt::lang_start':
hello.c3e402144fb7d6b4-cgu.0:(.text._ZN3std2rt10lang_start17hf8754b1fbdb05c66E+0x1a): undefined reference to `std::rt::lang_start_internal'
ld: a.o: in function `hello::main':
hello.c3e402144fb7d6b4-cgu.0:(.text._ZN5hello4main17ha49144bd44429a12E+0x31): undefined reference to `std::io::stdio::_print'
ld: a.o: in function `main':
hello.c3e402144fb7d6b4-cgu.0:(.text.main+0x21): undefined reference to `std::rt::lang_start_internal'

What am I doing wrong here?

2

There is no stable way to compile the emitted assembly to an executable, nor is there a stable way to link emitted object files to an executable. The only stable options are letting rustc do the compilation to object files and letting it invoke the linker or compiling to a staticlib and then manually linking this staticlib. In either case rustc will collect all necessary libraries for you and generate the so called allocator shim. There is no way to get assembly for the allocator shim and there is no stable way to get the full list of required static libraries you need to link.

Why do you want to manually compile emitted assembly?