unix,win: accept NAN/INFINITY as file timestamps (#4702)

Extend uv_fs_utime, uv_fs_futime and uv_fs_lutime to accept NAN and
INFINITY, with NAN meaning "don't touch the timestamp" and INFINITY
meaning "set to the current timestamp."

Ugly, but it avoids having to add uv_fs_utime2, etc.

UV_FS_UTIME_NOW and UV_FS_UTIME_OMIT constants have been added to make
it more palatable.

Fixes: https://github.com/libuv/libuv/issues/4665

3 files changed, 82 insertions, 61 deletions

diff --git a/src/unix/fs.c b/src/unix/fs.c
index 1631d934..717f3fab 100644
--- a/src/unix/fs.c
+++ b/src/unix/fs.c
@@ -203,8 +203,23 @@ static ssize_t uv__fs_fdatasync(uv_fs_t* req) {
 }
 
 
-UV_UNUSED(static struct timespec uv__fs_to_timespec(double time)) {
+#if defined(__APPLE__)                                                        \
+    || defined(_AIX71)                                                        \
+    || defined(__DragonFly__)                                                 \
+    || defined(__FreeBSD__)                                                   \
+    || defined(__HAIKU__)                                                     \
+    || defined(__NetBSD__)                                                    \
+    || defined(__OpenBSD__)                                                   \
+    || defined(__linux__)                                                     \
+    || defined(__sun)
+static struct timespec uv__fs_to_timespec(double time) {
   struct timespec ts;
+
+  if (uv__isinf(time))
+    return (struct timespec){UTIME_NOW, UTIME_NOW};
+  if (uv__isnan(time))
+    return (struct timespec){UTIME_OMIT, UTIME_OMIT};
+
   ts.tv_sec  = time;
   ts.tv_nsec = (time - ts.tv_sec) * 1e9;
 
@@ -221,41 +236,23 @@ UV_UNUSED(static struct timespec uv__fs_to_timespec(double time)) {
   }
   return ts;
 }
+#endif
 
-UV_UNUSED(static struct timeval uv__fs_to_timeval(double time)) {
-  struct timeval tv;
-  tv.tv_sec  = time;
-  tv.tv_usec = (time - tv.tv_sec) * 1e6;
-  if (tv.tv_usec < 0) {
-    tv.tv_usec += 1e6;
-    tv.tv_sec -= 1;
-  }
-  return tv;
-}
 
 static ssize_t uv__fs_futime(uv_fs_t* req) {
-#if defined(__linux__)                                                        \
+#if defined(__APPLE__)                                                        \
     || defined(_AIX71)                                                        \
-    || defined(__HAIKU__)                                                     \
-    || defined(__GNU__)
-  struct timespec ts[2];
-  ts[0] = uv__fs_to_timespec(req->atime);
-  ts[1] = uv__fs_to_timespec(req->mtime);
-  return futimens(req->file, ts);
-#elif defined(__APPLE__)                                                      \
     || defined(__DragonFly__)                                                 \
     || defined(__FreeBSD__)                                                   \
+    || defined(__HAIKU__)                                                     \
     || defined(__NetBSD__)                                                    \
     || defined(__OpenBSD__)                                                   \
+    || defined(__linux__)                                                     \
     || defined(__sun)
-  struct timeval tv[2];
-  tv[0] = uv__fs_to_timeval(req->atime);
-  tv[1] = uv__fs_to_timeval(req->mtime);
-# if defined(__sun)
-  return futimesat(req->file, NULL, tv);
-# else
-  return futimes(req->file, tv);
-# endif
+  struct timespec ts[2];
+  ts[0] = uv__fs_to_timespec(req->atime);
+  ts[1] = uv__fs_to_timespec(req->mtime);
+  return futimens(req->file, ts);
 #elif defined(__MVS__)
   attrib_t atr;
   memset(&atr, 0, sizeof(atr));
@@ -1142,25 +1139,20 @@ static ssize_t uv__fs_sendfile(uv_fs_t* req) {
 
 
 static ssize_t uv__fs_utime(uv_fs_t* req) {
-#if defined(__linux__)                                                         \
-    || defined(_AIX71)                                                         \
-    || defined(__sun)                                                          \
-    || defined(__HAIKU__)
+#if defined(__APPLE__)                                                        \
+    || defined(_AIX71)                                                        \
+    || defined(__DragonFly__)                                                 \
+    || defined(__FreeBSD__)                                                   \
+    || defined(__HAIKU__)                                                     \
+    || defined(__NetBSD__)                                                    \
+    || defined(__OpenBSD__)                                                   \
+    || defined(__linux__)                                                     \
+    || defined(__sun)
   struct timespec ts[2];
   ts[0] = uv__fs_to_timespec(req->atime);
   ts[1] = uv__fs_to_timespec(req->mtime);
   return utimensat(AT_FDCWD, req->path, ts, 0);
-#elif defined(__APPLE__)                                                      \
-    || defined(__DragonFly__)                                                 \
-    || defined(__FreeBSD__)                                                   \
-    || defined(__NetBSD__)                                                    \
-    || defined(__OpenBSD__)
-  struct timeval tv[2];
-  tv[0] = uv__fs_to_timeval(req->atime);
-  tv[1] = uv__fs_to_timeval(req->mtime);
-  return utimes(req->path, tv);
-#elif defined(_AIX)                                                           \
-    && !defined(_AIX71)
+#elif defined(_AIX) && !defined(_AIX71)
   struct utimbuf buf;
   buf.actime = req->atime;
   buf.modtime = req->mtime;
@@ -1181,24 +1173,19 @@ static ssize_t uv__fs_utime(uv_fs_t* req) {
 
 
 static ssize_t uv__fs_lutime(uv_fs_t* req) {
-#if defined(__linux__)            ||                                           \
-    defined(_AIX71)               ||                                           \
-    defined(__sun)                ||                                           \
-    defined(__HAIKU__)            ||                                           \
-    defined(__GNU__)              ||                                           \
-    defined(__OpenBSD__)
+#if defined(__APPLE__)                                                        \
+    || defined(_AIX71)                                                        \
+    || defined(__DragonFly__)                                                 \
+    || defined(__FreeBSD__)                                                   \
+    || defined(__HAIKU__)                                                     \
+    || defined(__NetBSD__)                                                    \
+    || defined(__OpenBSD__)                                                   \
+    || defined(__linux__)                                                     \
+    || defined(__sun)
   struct timespec ts[2];
   ts[0] = uv__fs_to_timespec(req->atime);
   ts[1] = uv__fs_to_timespec(req->mtime);
   return utimensat(AT_FDCWD, req->path, ts, AT_SYMLINK_NOFOLLOW);
-#elif defined(__APPLE__)          ||                                          \
-      defined(__DragonFly__)      ||                                          \
-      defined(__FreeBSD__)        ||                                          \
-      defined(__NetBSD__)
-  struct timeval tv[2];
-  tv[0] = uv__fs_to_timeval(req->atime);
-  tv[1] = uv__fs_to_timeval(req->mtime);
-  return lutimes(req->path, tv);
 #else
   errno = ENOSYS;
   return -1;
diff --git a/src/uv-common.h b/src/uv-common.h
index 372f0c4b..8e779ba5 100644
--- a/src/uv-common.h
+++ b/src/uv-common.h
@@ -31,6 +31,7 @@
 #include <stdarg.h>
 #include <stddef.h>
 #include <stdint.h>
+#include <string.h>
 
 #include "uv.h"
 #include "uv/tree.h"
@@ -448,4 +449,22 @@ struct uv__loop_internal_fields_s {
 # define UV_PTHREAD_MAX_NAMELEN_NP 16
 #endif
 
+/* Open-coded so downstream users don't have to link libm. */
+static inline int uv__isinf(double d) {
+  uint64_t v;
+
+  STATIC_ASSERT(sizeof(v) == sizeof(d));
+  memcpy(&v, &d, sizeof(v));
+  return (v << 1 >> 53) == 2047 && !(v << 12);
+}
+
+/* Open-coded so downstream users don't have to link libm. */
+static inline int uv__isnan(double d) {
+  uint64_t v;
+
+  STATIC_ASSERT(sizeof(v) == sizeof(d));
+  memcpy(&v, &d, sizeof(v));
+  return (v << 1 >> 53) == 2047 && !!(v << 12);
+}
+
 #endif /* UV_COMMON_H_ */
diff --git a/src/win/fs.c b/src/win/fs.c
index b4ed760e..27248f64 100644
--- a/src/win/fs.c
+++ b/src/win/fs.c
@@ -2580,14 +2580,29 @@ fchmod_cleanup:
 
 
 INLINE static int fs__utime_handle(HANDLE handle, double atime, double mtime) {
-  FILETIME filetime_a, filetime_m;
+  FILETIME filetime_as, *filetime_a = &filetime_as;
+  FILETIME filetime_ms, *filetime_m = &filetime_ms;
+  FILETIME now;
 
-  TIME_T_TO_FILETIME(atime, &filetime_a);
-  TIME_T_TO_FILETIME(mtime, &filetime_m);
+  if (uv__isinf(atime) || uv__isinf(mtime))
+    GetSystemTimeAsFileTime(&now);
 
-  if (!SetFileTime(handle, NULL, &filetime_a, &filetime_m)) {
+  if (uv__isinf(atime))
+    filetime_a = &now;
+  else if (uv__isnan(atime))
+    filetime_a = NULL;
+  else
+    TIME_T_TO_FILETIME(atime, filetime_a);
+
+  if (uv__isinf(mtime))
+    filetime_m = &now;
+  else if (uv__isnan(mtime))
+    filetime_m = NULL;
+  else
+    TIME_T_TO_FILETIME(mtime, filetime_m);
+
+  if (!SetFileTime(handle, NULL, filetime_a, filetime_m))
     return -1;
-  }
 
   return 0;
 }