Loading symbols that begin with an underscore - winapi

Question

My google-fu's weak regarding this issue… (edit/spoiler: _ isn't the issue after all, see below)
To provide some context, I'm developing a tiny portable program using Nim. At some time, I wanted to use getch() on win32 (using an old windows XP)…
The Nim doc says:
proc getch(): char {.raises: [], tags: [].}
Read a single character from the terminal, blocking until it is entered. The character is not printed to the terminal. This is not available for Windows.
… so eventually I used:
proc getch(): cint {.importc: "_getch", header: "<conio.h>".}
and that works fine for my needs. Later however, I tried using the dynlib pragma instead:
proc getch(): cint {.importc, dynlib: "msvcrt.dll".}
That fails at runtime: could not import: getch. No magic there, the symbol should start with an underscore! But _getch or even `_getch` are illegal in Nim.
(Note: there was allegedly a getch in the CRT but MS tells it's deprecated and we should use _getch instead.)
To make sure, I tried the same thing with a libc symbol Nim doesn't know about:
proc atoi(s: cstring): cint {.importc: "atoi", header: "<stdlib.h>".}
and
proc atoi(s: cstring): cint {.importc, dynlib: "msvcrt.dll".}
That works in both cases; atoi (obviously) doesn't begin with _.
I can do with the header pragma for now in this case, but that's a general issue I'm probably going to face again, hence my question:
How do I get to import symbols that begin with _ with the dynlibpragma?
The best would be an additional pragma in the same {. .}, as opposed to a flag when invoking the toolchain, but at this point any hint is welcome. I'm looking for a solution that doesn't rely on external libs or other languages.
Cheers.
(Nim 0.13.0)
EDIT: (in case others run in the same trouble)
OK, so I was chasing the wrong problem. As commented by #flyx, importc: "symbol" can be used with dynlib in the same way as in the header. The thing is, I had tried before and dismissed this combination for the wrong reasons (since Nim is still under heavy development, sometimes I have to take a guess… unlucky this time).
In fact:
proc getch(): cint {.importc: "_getch", dynlib: "msvcrt.dll".}
proc kbhit(): cint {.importc: "_kbhit", dynlib: "msvcrt.dll".}
didn't work for me. Not at compile time but at run time.
That still doesn't: _getch doesn't return until I Ctrl-C it (perhaps that's why it's not implemented on Windows in the first place!) and with a loop on _kbhit I need to kill the task.
proc getch(): cint {.importc: "_getch", header: "<conio.h>".}
proc kbhit(): cint {.importc: "_kbhit", header: "<conio.h>".}
DO work.
But because now I tested successfully
proc atoi64(s: cstring): clonglong {.importc: "_atoi64", dynlib: "msvcrt.dll".}
I can tell that the underscore is a non-issue.

Answer 1

Use:
proc getch(): cint {.importc: "_getch", dynlib: "msvcrt.dll".}