feat(Lib/signal): pidfd_send_signal

Author: litlighilit

src/pylib/Lib/signal_impl/signal_util.nim

@@ -1,4 +1,6 @@
 import ../../private/iph_utils
+import ../../pyconfig/ver
+import ./siginfo_decl
 import ./[state, chk_util, pylifecycle, pynsig, c_api]
 
 when HAVE_STRSIGNAL:
@@ -55,3 +57,15 @@ proc raise_signal*(signalnum: int) =
   if err != 0:
     raiseErrno()
   PyErr_CheckSignalsAndRaises()
+
+when defined(linux) and not (
+    defined(android) and ANDROID_API < 31):
+  proc syscall(sysno: cint): cint {.varargs, importc: "syscall", header: "<sys/syscall.h>".}
+  let NR_pidfd_send_signal{.importc: "__NR_pidfd_send_signal", header: "<unistd.h>".}: cint
+  # SYS_pidfd_send_signal is its newer name
+  proc pidfd_send_signal*(pid: int, sig: int,
+      siginfo: struct_siginfo = nil, flags = 0) =
+    let pid = cint(pid)
+    let sig = cint(sig)
+    if syscall(NR_pidfd_send_signal, pid, sig, nil, flags) < 0:
+      raiseErrno()

src/pylib/pyconfig/util.nim

@@ -1,8 +1,8 @@
 
 
 import std/os
-from std/strutils import parseInt
-
+from std/strutils import parseInt, strip
+import std/macros
 
 const weirdTarget = defined(js) or defined(nimscript)
 
@@ -60,6 +60,13 @@ template from_c_int*(variable; defval: int; precode): int =
     let variable{.importc, nodecl.}: cint
     stdout.write variable
 
+macro from_c_int_underlined*(variable: static[string]; defval: int): int =
+  let pureVar = variable.strip(chars = {'_'})
+  let pureVarId = newLit pureVar
+  result = quote do:
+    from_c_int(`variable`, `defval`):
+      {.emit: ["/*VARSECTION*/\n#define ", `pureVarId`, " ", `variable`].}
+
 template from_c_int*(variable; includeFile: static[string], defval = low(int)): int =
   ## we know int.low is smaller than low(cint)
   bind handle_int_or_strint

src/pylib/pyconfig/ver.nim

@@ -0,0 +1,7 @@
+
+
+when defined(android):
+  import ./util
+  const ANDROID_API* = from_c_int_underlined("__ANDROID_API__", 0)
+else:
+  const ANDROID_API* = 0