fix(wasi): date clock resolution and system datetime support

date implements get_clock_resolution via libc::clock_getres (rustix's
excludes WASI) and set_system_datetime for WASI, the latter reporting
"not supported" since the sandbox has no wall-clock-set syscall.

Author: eduardomourar

src/uu/date/Cargo.toml

@@ -43,6 +43,9 @@ uucore = { workspace = true, features = ["parser", "i18n-datetime"] }
 libc = { workspace = true }
 rustix = { workspace = true, features = ["time"] }
 
+[target.'cfg(target_os = "wasi")'.dependencies]
+libc = { workspace = true }
+
 [target.'cfg(windows)'.dependencies]
 windows-sys = { workspace = true, features = [
   "Win32_Foundation",

src/uu/date/locales/en-US.ftl

@@ -103,6 +103,7 @@ date-error-expected-file-got-directory = expected file, got directory {$path}
 date-error-date-overflow = date overflow '{$date}'
 date-error-setting-date-not-supported-macos = setting the date is not supported by macOS
 date-error-setting-date-not-supported-redox = setting the date is not supported by Redox
+date-error-setting-date-not-supported-wasi = setting the date is not supported by WASI
 date-error-cannot-set-date = cannot set date
 date-error-extra-operand = extra operand '{$operand}'
 date-error-write = write error: {$error}

src/uu/date/locales/fr-FR.ftl

@@ -98,6 +98,7 @@ date-error-expected-file-got-directory = fichier attendu, répertoire obtenu {$p
 date-error-date-overflow = débordement de date '{$date}'
 date-error-setting-date-not-supported-macos = la définition de la date n'est pas prise en charge par macOS
 date-error-setting-date-not-supported-redox = la définition de la date n'est pas prise en charge par Redox
+date-error-setting-date-not-supported-wasi = la définition de la date n'est pas prise en charge par WASI
 date-error-cannot-set-date = impossible de définir la date
 date-error-extra-operand = opérande supplémentaire '{$operand}'
 date-error-write = erreur d'écriture: {$error}

src/uu/date/src/date.rs

@@ -1173,7 +1173,23 @@ fn parse_date<S: AsRef<str>>(
     }
 }
 
-#[cfg(not(any(unix, windows)))]
+#[cfg(target_os = "wasi")]
+/// Returns the resolution of the system's realtime clock.
+///
+/// `rustix::time::clock_getres` excludes WASI, so call `libc::clock_getres`
+/// (available on WASI) directly instead.
+fn get_clock_resolution() -> Timestamp {
+    let timespec = unsafe {
+        let mut timespec: libc::timespec = std::mem::zeroed();
+        libc::clock_getres(libc::CLOCK_REALTIME, &raw mut timespec);
+        timespec
+    };
+
+    #[allow(clippy::unnecessary_cast, reason = "needed for 32 bit target")]
+    Timestamp::constant(timespec.tv_sec as _, timespec.tv_nsec as _)
+}
+
+#[cfg(not(any(unix, windows, target_os = "wasi")))]
 fn get_clock_resolution() -> Timestamp {
     unimplemented!("getting clock resolution not implemented (unsupported target)");
 }
@@ -1212,7 +1228,7 @@ fn get_clock_resolution() -> Timestamp {
     Timestamp::constant(0, 100)
 }
 
-#[cfg(not(any(unix, windows)))]
+#[cfg(not(any(unix, windows, target_os = "wasi")))]
 fn set_system_datetime(_date: Zoned) -> UResult<()> {
     unimplemented!("setting date not implemented (unsupported target)");
 }
@@ -1234,6 +1250,15 @@ fn set_system_datetime(_date: Zoned) -> UResult<()> {
     ))
 }
 
+#[cfg(target_os = "wasi")]
+/// The WASI sandbox has no syscall for setting the wall clock.
+fn set_system_datetime(_date: Zoned) -> UResult<()> {
+    Err(USimpleError::new(
+        1,
+        translate!("date-error-setting-date-not-supported-wasi"),
+    ))
+}
+
 #[cfg(target_os = "redox")]
 fn set_system_datetime(_date: Zoned) -> UResult<()> {
     Err(USimpleError::new(