From 8f3f1c30058e13987833525a6c7d0f33ce070480 Mon Sep 17 00:00:00 2001
From: Dev <9416650+aoinoikaz@users.noreply.github.com>
Date: Tue, 3 Nov 2026 18:11:01 -0500
Subject: [PATCH] lib: windows: _read: Call NtReadFile, rather than read.

lib/windows/_read.c answered with read, which kaem.windows.run builds
from lib/windows/read.c, the bare NtReadFile, beside the stub
__buffered_read.  configure-lib.sh's lists build read from
lib/posix/buffered-read.c instead, whose __buffered_read fills its buffer
with _read, so read, __buffered_read and _read called one another until
the stack ran out.  Mes compiled by MesCC died with STATUS_STACK_OVERFLOW
once it had opened boot-5.scm, having printed nothing.  _read is now the
bare NtReadFile, as lib/linux/_read.c is the bare SYS_read, and read.c,
which only the build without the buffer uses, calls it.

* lib/windows/_read.c (_read): Call NtReadFile, moved here from read.c.
* lib/windows/read.c (read): Call _read.
* kaem.windows.run: Build lib/windows/_read.c ahead of read.c.
---
 kaem.windows.run    |  1 +
 lib/windows/_read.c | 32 +++++++++++++++++++++++++-------
 lib/windows/read.c  | 26 +++++---------------------
 3 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/kaem.windows.run b/kaem.windows.run
index e18c8176..3caa60e5 100755
--- a/kaem.windows.run
+++ b/kaem.windows.run
@@ -84,6 +84,7 @@ M2-Planet                                               \
     -f ${srcdest}lib/linux/malloc.c                    \
     -f ${srcdest}lib/windows/ntdll.c                   \
     -f ${srcdest}lib/string/memset.c                   \
+    -f ${srcdest}lib/windows/_read.c                   \
     -f ${srcdest}lib/windows/read.c                    \
     -f ${srcdest}lib/mes/fdgetc.c                      \
     -f ${srcdest}lib/stdio/getchar.c                   \
diff --git a/lib/windows/_read.c b/lib/windows/_read.c
index fd411091..97596fc6 100644
--- a/lib/windows/_read.c
+++ b/lib/windows/_read.c
@@ -16,16 +16,34 @@
  * You should have received a copy of the GNU General Public License
  * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
  */
-
-/* Stands in for lib/linux/_read.c.  On Linux _read is the bare SYS_read and
- * read is the same call; here read (lib/windows/read.c) is already the bare
- * NtReadFile with nothing between, so this is that. */
-
+#include <windows/ntcall.h>
+#include <windows/ntdll.h>
 #include <mes/lib.h>
-#include <unistd.h>
+#include <fcntl.h>
+
+/* Stands in for lib/linux/_read.c: the bare read, with nothing above it.
+ * configure-lib.sh's lists build read from lib/posix/buffered-read.c, whose
+ * __buffered_read fills its buffer with this, so this must not call read.
+ * NtReadFile is NtWriteFile's twin, and an NTSTATUS below zero is how the end
+ * of the file arrives as much as how a failure does -- both mean nothing more
+ * was read, which is what a caller of read wants to hear as 0. */
 
 ssize_t
 _read (int filedes, void *buffer, size_t size)
 {
-  return read (filedes, buffer, size);
+  int NtReadFile;
+  int *iosb;
+  int handle;
+  int rc;
+
+  NtReadFile = __ntdll_resolve ("NtReadFile");
+  iosb = __iosb ();
+  iosb[0] = 0;
+  iosb[1] = 0;
+  handle = __handle (filedes);
+
+  rc = __ntcall9 (NtReadFile, handle, 0, 0, 0, iosb, buffer, size, 0, 0);
+  if (rc < 0)
+    return 0;
+  return iosb[1];
 }
diff --git a/lib/windows/read.c b/lib/windows/read.c
index 06d0c1e9..375256c5 100644
--- a/lib/windows/read.c
+++ b/lib/windows/read.c
@@ -16,32 +16,16 @@
  * You should have received a copy of the GNU General Public License
  * along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.
  */
-#include <windows/ntcall.h>
-#include <windows/ntdll.h>
 #include <mes/lib.h>
 #include <fcntl.h>
 
-/* Stands in for lib/linux/read.c.  NtReadFile is NtWriteFile's twin, and an
- * NTSTATUS below zero is how the end of the file arrives as much as how a
- * failure does -- both mean nothing more was read, which is what a caller of
- * read wants to hear as 0. */
+/* Stands in for lib/linux/read.c, for a build that buffers nothing, as
+ * kaem.windows.run's does: there read is lib/windows/_read.c's bare
+ * NtReadFile.  configure-lib.sh's lists take read from
+ * lib/posix/buffered-read.c instead, and do not build this file. */
 
 ssize_t
 read (int filedes, void *buffer, size_t size)
 {
-  int NtReadFile;
-  int *iosb;
-  int handle;
-  int rc;
-
-  NtReadFile = __ntdll_resolve ("NtReadFile");
-  iosb = __iosb ();
-  iosb[0] = 0;
-  iosb[1] = 0;
-  handle = __handle (filedes);
-
-  rc = __ntcall9 (NtReadFile, handle, 0, 0, 0, iosb, buffer, size, 0, 0);
-  if (rc < 0)
-    return 0;
-  return iosb[1];
+  return _read (filedes, buffer, size);
 }