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13965 :: {.compile.} for submodules and pathing for os=any

• dwhall256 (orginal) [2026-06-06T15:41:32+02:00] view original

  I have one problem where the straightforward fix leads to a second problem. My host pc is Win 11 and I'm building from a cmd.exe terminal. The project I'm trying to build cross-compiles to arm32 and is configured with switch("os", "any") (among many others for embedded cross-compilation).

  Problem 1: Using the .compile pragma in a submodule

  • Root project: D:\folder\myproj
  • Submodule: D:\folder\myproj\deps\krnl
  • Build target: D:\folder\myproj\deps\krnl\src\krnlpkg\debug_rtt.nim:

  
  import std/os
  
  when defined(debug):
    const rttDir = currentSourcePath().parentDir()
    static:
      echo "A: " & currentSourcePath()
      echo "B: " & $currentSourcePath().splitPath()
      echo "C: " & currentSourcePath().parentDir()
      echo "D: " & rttDir
    {.localPassC: "-I" & (rttDir / "RTT").}
    {.localPassC: "-I" & (rttDir / "Config").}
    {.compile: rttDir / "RTT" / "SEGGER_RTT.c".}
    {.compile: rttDir / "RTT" / "SEGGER_RTT_printf.c".}
  Run

  I first tried passing a relative path to the .localPassC pragma. But because the Nim compiler was targeting myproj, a path relative to the submodule was incorrect for the "-I" argument. Now, in the code above you see me trying to build an absolute path to give to -I.

  The C files compile successfully, but I'm getting "No such file or directory" for the header files.

  Problem 2: splitPath() and parentDir() aren't working

  The output of the snippet above is:

  
  A: d:\folder\myproj\deps\krnl\src\krnlpkg\debug_rtt.nim
  B: (head: "", tail: "d:\\folder\\myproj\\deps\\krnl\\src\\krnlpkg\\debug_rtt.nim")
  C:
  D: .
  Run

  This is where I'm stuck. Is this due to os=any? Is it the correct approach to try to build the absolute address for the -I argument? Is there a better way?

  thanks,

  !!Dean

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• elcritch (orginal) [2026-06-06T17:41:40+02:00] view original

  Yeah likely due to --os:any? There was some discussion on Discord a while back about this sort of issue where the compile time env != runtime env.

  If you do --verbosity:3 Nim compiler will print out the C compiler commands it's using as well.

  splitPath uses the DirSep const.

  Probably the quickest is to do your own "splitPath", but there may be some way to set the os of the compile time VM differently than the runtime.

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• Araq (orginal) [2026-06-06T17:41:52+02:00] view original

  I don't know. Let an AI convert https://github.com/SEGGERMicro/RTT/blob/main/RTT/SEGGER_RTT.c to Nim and use that instead. The code is full of unverifiable memory accesses btw, avoid it.

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• elcritch (orginal) [2026-06-06T17:42:24+02:00] view original

  It'd be nice if splitPath and friends took DirSep as a default arg.

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• Araq (orginal) [2026-06-06T17:45:20+02:00] view original

  The real solution here is to patch the stdlib to always produce / even on Windows as it works there too.

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