fix test

lib/system/ansi_c.nim

@@ -117,15 +117,25 @@ type
   CFilePtr* = ptr CFile ## The type representing a file handle.
 
 # duplicated between io and ansi_c
-const stdioUsesMacros = (defined(osx) or defined(freebsd) or defined(dragonfly)) and not defined(emscripten)
-const stderrName = when stdioUsesMacros: "__stderrp" else: "stderr"
-const stdoutName = when stdioUsesMacros: "__stdoutp" else: "stdout"
-const stdinName = when stdioUsesMacros: "__stdinp" else: "stdin"
+# xxx super hacky, can be fixed by calling preprocessor
+# see https://github.com/nim-lang/RFCs/issues/205 prop 5
+when (defined(osx) or defined(freebsd) or defined(dragonfly)) and not defined(emscripten):
+  const stdinName = "__stdinp"
+  const stdoutName = "__stdoutp"
+  const stderrName = "__stderrp"
+elif defined(openbsd) and not defined(emscripten):
+  const stdinName = "(&__sF[0])"
+  const stdoutName = "(&__sF[1])"
+  const stderrName = "(&__sF[2])"
+else:
+  const stdinName = "stdin"
+  const stdoutName = "stdout"
+  const stderrName = "stderr"
 
 var
-  cstderr* {.importc: stderrName, header: "<stdio.h>".}: CFilePtr
-  cstdout* {.importc: stdoutName, header: "<stdio.h>".}: CFilePtr
   cstdin* {.importc: stdinName, header: "<stdio.h>".}: CFilePtr
+  cstdout* {.importc: stdoutName, header: "<stdio.h>".}: CFilePtr
+  cstderr* {.importc: stderrName, header: "<stdio.h>".}: CFilePtr
 
 proc c_fprintf*(f: CFilePtr, frmt: cstring): cint {.
   importc: "fprintf", header: "<stdio.h>", varargs, discardable.}