From e4edcf23e0e57ef1d7b28420af357378a91261a9 Mon Sep 17 00:00:00 2001
From: Alex Waygood <Alex.Waygood@Gmail.com>
Date: Sun, 8 Oct 2023 00:05:20 +0200
Subject: [PATCH] Fix platform availability of some Unix constants (#10857)

---
 stdlib/_curses.pyi                   |  3 ++-
 stdlib/os/__init__.pyi               | 17 ++++++++++++++---
 stdlib/select.pyi                    |  1 -
 stdlib/signal.pyi                    | 10 ++++++----
 tests/stubtest_allowlists/darwin.txt |  5 -----
 tests/stubtest_allowlists/linux.txt  |  6 ------
 6 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/stdlib/_curses.pyi b/stdlib/_curses.pyi
index e2319a5fc..3604f7abe 100644
--- a/stdlib/_curses.pyi
+++ b/stdlib/_curses.pyi
@@ -61,7 +61,8 @@ if sys.platform != "win32":
     A_DIM: int
     A_HORIZONTAL: int
     A_INVIS: int
-    A_ITALIC: int
+    if sys.platform != "darwin":
+        A_ITALIC: int
     A_LEFT: int
     A_LOW: int
     A_NORMAL: int
diff --git a/stdlib/os/__init__.pyi b/stdlib/os/__init__.pyi
index 27e951e9f..7fd04218f 100644
--- a/stdlib/os/__init__.pyi
+++ b/stdlib/os/__init__.pyi
@@ -70,9 +70,20 @@ if sys.platform != "win32":
         POSIX_FADV_WILLNEED: int
         POSIX_FADV_DONTNEED: int
 
-    SF_NODISKIO: int
-    SF_MNOWAIT: int
-    SF_SYNC: int
+    if sys.platform != "linux" and sys.platform != "darwin":
+        # In the os-module docs, these are marked as being available
+        # on "Unix, not Emscripten, not WASI."
+        # However, in the source code, a comment indicates they're "FreeBSD constants".
+        # sys.platform could have one of many values on a FreeBSD Python build,
+        # so the sys-module docs recommend doing `if sys.platform.startswith('freebsd')`
+        # to detect FreeBSD builds. Unfortunately that would be too dynamic
+        # for type checkers, however.
+        SF_NODISKIO: int
+        SF_MNOWAIT: int
+        SF_SYNC: int
+
+        if sys.version_info >= (3, 11):
+            SF_NOCACHE: int
 
     if sys.platform == "linux":
         XATTR_SIZE_MAX: int
diff --git a/stdlib/select.pyi b/stdlib/select.pyi
index 99b66126a..5e2828e42 100644
--- a/stdlib/select.pyi
+++ b/stdlib/select.pyi
@@ -137,7 +137,6 @@ if sys.platform == "linux":
     EPOLLRDNORM: int
     EPOLLWRBAND: int
     EPOLLWRNORM: int
-    EPOLL_RDHUP: int
     EPOLL_CLOEXEC: int
 
 if sys.platform != "linux" and sys.platform != "darwin" and sys.platform != "win32":
diff --git a/stdlib/signal.pyi b/stdlib/signal.pyi
index b0d1e4417..906a6dabe 100644
--- a/stdlib/signal.pyi
+++ b/stdlib/signal.pyi
@@ -21,8 +21,6 @@ class Signals(IntEnum):
         CTRL_C_EVENT: int
         CTRL_BREAK_EVENT: int
     else:
-        SIGEMT: int
-        SIGINFO: int
         SIGALRM: int
         SIGBUS: int
         SIGCHLD: int
@@ -47,6 +45,9 @@ class Signals(IntEnum):
         SIGWINCH: int
         SIGXCPU: int
         SIGXFSZ: int
+        if sys.platform != "linux":
+            SIGEMT: int
+            SIGINFO: int
         if sys.platform != "darwin":
             SIGCLD: int
             SIGPOLL: int
@@ -88,8 +89,9 @@ if sys.platform == "win32":
     CTRL_C_EVENT: Signals
     CTRL_BREAK_EVENT: Signals
 else:
-    SIGINFO: Signals
-    SIGEMT: Signals
+    if sys.platform != "linux":
+        SIGINFO: Signals
+        SIGEMT: Signals
     SIGALRM: Signals
     SIGBUS: Signals
     SIGCHLD: Signals
diff --git a/tests/stubtest_allowlists/darwin.txt b/tests/stubtest_allowlists/darwin.txt
index d0e3176c6..8e6610488 100644
--- a/tests/stubtest_allowlists/darwin.txt
+++ b/tests/stubtest_allowlists/darwin.txt
@@ -1,9 +1,4 @@
-_?curses.A_ITALIC
-
 _posixsubprocess.cloexec_pipe
-os.SF_MNOWAIT
-os.SF_NODISKIO
-os.SF_SYNC
 (os|posix).sched_param  # system dependent. Unclear if macos has it.
 select.KQ_FILTER_NETDEV  # system dependent
 select.kqueue.__init__  # default C signature is wrong
diff --git a/tests/stubtest_allowlists/linux.txt b/tests/stubtest_allowlists/linux.txt
index 97a4f867c..f2386ae01 100644
--- a/tests/stubtest_allowlists/linux.txt
+++ b/tests/stubtest_allowlists/linux.txt
@@ -1,13 +1,7 @@
 _socket.*
 _posixsubprocess.cloexec_pipe
-os.SF_MNOWAIT
-os.SF_NODISKIO
-os.SF_SYNC
 os.plock
-select.EPOLL_RDHUP
 selectors.KqueueSelector
-signal.SIGEMT
-signal.SIGINFO
 socket.[A-Z0-9_]+
 
 # Exists at runtime, but missing from stubs