osproc: Define and select spawn/fork same way

Previously startProcessAuxFork was defined even when it was unused, also the
compile time condition to select spawn vs fork was not always the same for
definitions and calls.

This change just defines the condition in one place as constant, then in other
places we just check for `when useProcessAuxSpawn`.

1 files changed, 39 insertions, 38 deletions

diff --git a/lib/pure/osproc.nim b/lib/pure/osproc.nim
index 81befccff..7431be702 100644
--- a/lib/pure/osproc.nim
+++ b/lib/pure/osproc.nim
@@ -614,11 +614,14 @@ elif not defined(useNimRtl):
     optionPoStdErrToStdOut: bool
   {.deprecated: [TStartProcessData: StartProcessData].}
 
-  when not defined(useFork):
+  const useProcessAuxSpawn = declared(posix_spawn) and not defined(useFork) and
+                             not defined(useClone) and not defined(linux)
+  when useProcessAuxSpawn:
     proc startProcessAuxSpawn(data: StartProcessData): Pid {.
       tags: [ExecIOEffect, ReadEnvEffect], gcsafe.}
-  proc startProcessAuxFork(data: StartProcessData): Pid {.
-    tags: [ExecIOEffect, ReadEnvEffect], gcsafe.}
+  else:
+    proc startProcessAuxFork(data: StartProcessData): Pid {.
+      tags: [ExecIOEffect, ReadEnvEffect], gcsafe.}
   {.push stacktrace: off, profiler: off.}
   proc startProcessAfterFork(data: ptr StartProcessData) {.
     tags: [ExecIOEffect, ReadEnvEffect], cdecl, gcsafe.}
@@ -674,9 +677,7 @@ elif not defined(useNimRtl):
     data.optionPoStdErrToStdOut = poStdErrToStdOut in options
     data.workingDir = workingDir
 
-
-    when declared(posix_spawn) and not defined(useFork) and
-        not defined(useClone) and not defined(linux):
+    when useProcessAuxSpawn:
       pid = startProcessAuxSpawn(data)
     else:
       pid = startProcessAuxFork(data)
@@ -706,7 +707,7 @@ elif not defined(useNimRtl):
       discard close(pStdin[readIdx])
       discard close(pStdout[writeIdx])
 
-  when not defined(useFork):
+  when useProcessAuxSpawn:
     proc startProcessAuxSpawn(data: StartProcessData): Pid =
       var attr: Tposix_spawnattr
       var fops: Tposix_spawn_file_actions
@@ -752,43 +753,43 @@ elif not defined(useNimRtl):
       discard posix_spawnattr_destroy(attr)
       chck res
       return pid
+  else:
+    proc startProcessAuxFork(data: StartProcessData): Pid =
+      if pipe(data.pErrorPipe) != 0:
+        raiseOSError(osLastError())
 
-  proc startProcessAuxFork(data: StartProcessData): Pid =
-    if pipe(data.pErrorPipe) != 0:
-      raiseOSError(osLastError())
+      defer:
+        discard close(data.pErrorPipe[readIdx])
 
-    defer:
-      discard close(data.pErrorPipe[readIdx])
+      var pid: Pid
+      var dataCopy = data
+
+      when defined(useClone):
+        const stackSize = 65536
+        let stackEnd = cast[clong](alloc(stackSize))
+        let stack = cast[pointer](stackEnd + stackSize)
+        let fn: pointer = startProcessAfterFork
+        pid = clone(fn, stack,
+                    cint(CLONE_VM or CLONE_VFORK or SIGCHLD),
+                    pointer(addr dataCopy), nil, nil, nil)
+        discard close(data.pErrorPipe[writeIdx])
+        dealloc(stack)
+      else:
+        pid = fork()
+        if pid == 0:
+          startProcessAfterFork(addr(dataCopy))
+          exitnow(1)
 
-    var pid: Pid
-    var dataCopy = data
-
-    when defined(useClone):
-      const stackSize = 65536
-      let stackEnd = cast[clong](alloc(stackSize))
-      let stack = cast[pointer](stackEnd + stackSize)
-      let fn: pointer = startProcessAfterFork
-      pid = clone(fn, stack,
-                  cint(CLONE_VM or CLONE_VFORK or SIGCHLD),
-                  pointer(addr dataCopy), nil, nil, nil)
       discard close(data.pErrorPipe[writeIdx])
-      dealloc(stack)
-    else:
-      pid = fork()
-      if pid == 0:
-        startProcessAfterFork(addr(dataCopy))
-        exitnow(1)
-
-    discard close(data.pErrorPipe[writeIdx])
-    if pid < 0: raiseOSError(osLastError())
+      if pid < 0: raiseOSError(osLastError())
 
-    var error: cint
-    let sizeRead = read(data.pErrorPipe[readIdx], addr error, sizeof(error))
-    if sizeRead == sizeof(error):
-      raiseOSError("Could not find command: '$1'. OS error: $2" %
-          [$data.sysCommand, $strerror(error)])
+      var error: cint
+      let sizeRead = read(data.pErrorPipe[readIdx], addr error, sizeof(error))
+      if sizeRead == sizeof(error):
+        raiseOSError("Could not find command: '$1'. OS error: $2" %
+            [$data.sysCommand, $strerror(error)])
 
-    return pid
+      return pid
 
   {.push stacktrace: off, profiler: off.}
   proc startProcessFail(data: ptr StartProcessData) =