From 5ee3212078e12f28ada17c2db033363029443f4a Mon Sep 17 00:00:00 2001
From: Yonggang Luo <luoyonggang@gmail.com>
Date: Tue, 29 Mar 2022 00:41:50 +0800
Subject: [PATCH] util: Add os_create_anonymous_file support on win32

Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18017>
---
 src/util/anon_file.c | 20 +++++++++++++++++---
 src/util/anon_file.h |  5 +++--
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/util/anon_file.c b/src/util/anon_file.c
index e2d9265194d2f..983ff75ac02ab 100644
--- a/src/util/anon_file.c
+++ b/src/util/anon_file.c
@@ -27,9 +27,10 @@
  * Based on weston shared/os-compatibility.c
  */
 
-#ifndef _WIN32
 #include "anon_file.h"
 
+#ifndef _WIN32
+
 #include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
@@ -112,7 +113,7 @@ create_tmpfile_cloexec(char *tmpname)
  * SCM_RIGHTS methods.
  */
 int
-os_create_anonymous_file(off_t size, const char *debug_name)
+os_create_anonymous_file(int64_t size, const char *debug_name)
 {
    int fd, ret;
 #if defined(HAVE_MEMFD_CREATE)
@@ -155,7 +156,7 @@ os_create_anonymous_file(off_t size, const char *debug_name)
    if (fd < 0)
       return -1;
 
-   ret = ftruncate(fd, size);
+   ret = ftruncate(fd, (off_t)size);
    if (ret < 0) {
       close(fd);
       return -1;
@@ -163,4 +164,17 @@ os_create_anonymous_file(off_t size, const char *debug_name)
 
    return fd;
 }
+#else
+
+#include <windows.h>
+#include <io.h>
+
+int
+os_create_anonymous_file(int64_t size, const char *debug_name)
+{
+   (void)debug_name;
+   HANDLE h = CreateFileMappingW(INVALID_HANDLE_VALUE, NULL,
+      PAGE_READWRITE, (size >> 32), size & 0xFFFFFFFF, NULL);
+   return _open_osfhandle((intptr_t)h, 0);
+}
 #endif
diff --git a/src/util/anon_file.h b/src/util/anon_file.h
index 790537b7aee6f..bdd74205d90e1 100644
--- a/src/util/anon_file.h
+++ b/src/util/anon_file.h
@@ -26,8 +26,9 @@
 #ifndef _ANON_FILE_H_
 #define _ANON_FILE_H_
 
-#include <sys/types.h>
+#include <stdint.h>
 
-int os_create_anonymous_file(off_t size, const char *debug_name);
+/* On win32, off_t is only 32 bit, so always using 64 bit size */
+int os_create_anonymous_file(int64_t size, const char *debug_name);
 
 #endif