From 314b584cef019fb569c676a93e1e469a680244a7 Mon Sep 17 00:00:00 2001
From: ada <ada@cubething.dev>
Date: Wed, 29 Apr 2026 11:48:09 -0500
Subject: [PATCH 1/3] Enable mmap

Empirical enablement per
.vault/designs/stdlib-modules-enablement/design.md.
Drop [mmap] from the Nanvix arm of PY_STDLIB_MOD_SET_NA in
configure.ac and the matching py_cv_module_mmap=n/a in configure.

Closes #301 (pending verification).
---
 configure    | 1 -
 configure.ac | 1 -
 2 files changed, 2 deletions(-)

diff --git a/configure b/configure
index 36793a809578bb..417d3a1842d7b8 100755
--- a/configure
+++ b/configure
@@ -28622,7 +28622,6 @@ case $ac_sys_system in #(
     py_cv_module__lsprof=n/a
     py_cv_module__multiprocessing=n/a
     py_cv_module_audioop=n/a
-    py_cv_module_mmap=n/a
     py_cv_module__posixshmem=n/a
     py_cv_module_fcntl=n/a
     py_cv_module_grp=n/a
diff --git a/configure.ac b/configure.ac
index 95a47ba57cec8e..416d77b6dc265d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -7270,7 +7270,6 @@ AS_CASE([$ac_sys_system],
       [_lsprof],
       [_multiprocessing],
       [audioop],
-      [mmap],
       [_posixshmem],
       [fcntl],
       [grp],

From 1b2f873e5f99d7ea01d158996abf20c47e6c71a2 Mon Sep 17 00:00:00 2001
From: ada <ada@cubething.dev>
Date: Wed, 29 Apr 2026 11:53:01 -0500
Subject: [PATCH 2/3] mmap: gate msync() on HAVE_MSYNC

Cycle 2 of the empirical enablement of issue #301. Cycle 1 (commit
8dd17c2fde3) flipped the configure switch and confirmed that
Modules/mmapmodule.c:683 calls msync() unconditionally inside
mmap.flush(), and that nanvix's libposix.a does not export msync
(see .vault/designs/stdlib-modules-enablement/findings.md).

This commit:
- adds msync to the AC_CHECK_FUNCS list in configure.ac (alongside
  the existing mmap/mremap entries) and mirrors the change in the
  generated configure script (no autoreconf, per port convention).
- adds HAVE_MSYNC to pyconfig.h.in so the autoconf substitution
  has a target.
- guards the UNIX msync() branch in mmap_flush_method() with
  defined(HAVE_MSYNC); platforms without msync fall through to the
  existing 'flush not supported on this system' ValueError path.

On any platform that has msync (every existing in-tree target),
HAVE_MSYNC will be defined and behaviour is unchanged. On nanvix,
mmap.flush() will raise ValueError instead of failing to link.
---
 Modules/mmapmodule.c | 2 +-
 configure            | 7 +++++++
 configure.ac         | 2 +-
 pyconfig.h.in        | 3 +++
 4 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/Modules/mmapmodule.c b/Modules/mmapmodule.c
index 827f619e6eb8b6..22524f8f632b52 100644
--- a/Modules/mmapmodule.c
+++ b/Modules/mmapmodule.c
@@ -678,7 +678,7 @@ mmap_flush_method(mmap_object *self, PyObject *args)
         return NULL;
     }
     Py_RETURN_NONE;
-#elif defined(UNIX)
+#elif defined(UNIX) && defined(HAVE_MSYNC)
     /* XXX flags for msync? */
     if (-1 == msync(self->data + offset, size, MS_SYNC)) {
         PyErr_SetFromErrno(PyExc_OSError);
diff --git a/configure b/configure
index 417d3a1842d7b8..0eb5dd4e1c1534 100755
--- a/configure
+++ b/configure
@@ -18042,6 +18042,12 @@ if test "x$ac_cv_func_mremap" = xyes
 then :
   printf "%s\n" "#define HAVE_MREMAP 1" >>confdefs.h
 
+fi
+ac_fn_c_check_func "$LINENO" "msync" "ac_cv_func_msync"
+if test "x$ac_cv_func_msync" = xyes
+then :
+  printf "%s\n" "#define HAVE_MSYNC 1" >>confdefs.h
+
 fi
 ac_fn_c_check_func "$LINENO" "nice" "ac_cv_func_nice"
 if test "x$ac_cv_func_nice" = xyes
@@ -28656,6 +28662,7 @@ case $ac_sys_system in #(
     py_cv_module__testmultiphase=n/a
     py_cv_module__testsinglephase=n/a
     py_cv_module__testclinic=n/a
+    py_cv_module_=n/a
 
    ;; #(
   Emscripten|WASI) :
diff --git a/configure.ac b/configure.ac
index 416d77b6dc265d..a9aa01a5347c96 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4908,7 +4908,7 @@ AC_CHECK_FUNCS([ \
   getpwent getpwnam_r getpwuid getpwuid_r getresgid getresuid getrusage getsid getspent \
   getspnam getuid getwd if_nameindex initgroups kill killpg lchown linkat \
   lockf lstat lutimes madvise mbrtowc memrchr mkdirat mkfifo mkfifoat \
-  mknod mknodat mktime mmap mremap nice openat opendir pathconf pause pipe \
+  mknod mknodat mktime mmap mremap msync nice openat opendir pathconf pause pipe \
   pipe2 plock poll posix_fadvise posix_fallocate posix_spawn posix_spawnp \
   pread preadv preadv2 pthread_condattr_setclock pthread_init pthread_kill \
   pwrite pwritev pwritev2 readlink readlinkat readv realpath renameat \
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 6d370f6664c10c..002b619d798b74 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -823,6 +823,9 @@
 /* Define to 1 if you have the `mremap' function. */
 #undef HAVE_MREMAP
 
+/* Define to 1 if you have the `msync' function. */
+#undef HAVE_MSYNC
+
 /* Define to 1 if you have the `nanosleep' function. */
 #undef HAVE_NANOSLEEP
 

From 6845007d356ceefd8445639e01a06bb6ad47e5d2 Mon Sep 17 00:00:00 2001
From: ada <ada@cubething.dev>
Date: Wed, 29 Apr 2026 15:14:53 -0500
Subject: [PATCH 3/3] revert configure change

---
 configure | 1 -
 1 file changed, 1 deletion(-)

diff --git a/configure b/configure
index 0eb5dd4e1c1534..2b29d7d8e80805 100755
--- a/configure
+++ b/configure
@@ -28662,7 +28662,6 @@ case $ac_sys_system in #(
     py_cv_module__testmultiphase=n/a
     py_cv_module__testsinglephase=n/a
     py_cv_module__testclinic=n/a
-    py_cv_module_=n/a
 
    ;; #(
   Emscripten|WASI) :