Change environment variable getters to error recoverably

library/std/src/env.rs

@@ -185,15 +185,9 @@ impl fmt::Debug for VarsOs {
 ///
 /// # Errors
 ///
-/// Errors if the environment variable is not present.
-/// Errors if the environment variable is not valid Unicode. If this is not desired, consider using
-/// [`var_os`].
-///
-/// # Panics
-///
-/// This function may panic if `key` is empty, contains an ASCII equals sign
-/// `'='` or the NUL character `'\0'`, or when the value contains the NUL
-/// character.
+/// Returns `[None]` if the environment variable isn't set.
+/// Returns `[None]` if the environment variable is not valid Unicode. If this is not
+/// desired, consider using [`var_os`].
 ///
 /// # Examples
 ///
@@ -219,18 +213,17 @@ fn _var(key: &OsStr) -> Result<String, VarError> {
 }
 
 /// Fetches the environment variable `key` from the current process, returning
-/// [`None`] if the variable isn't set.
-///
-/// # Panics
-///
-/// This function may panic if `key` is empty, contains an ASCII equals sign
-/// `'='` or the NUL character `'\0'`, or when the value contains the NUL
-/// character.
+/// [`None`] if the variable isn't set or there's another error.
 ///
 /// Note that the method will not check if the environment variable
 /// is valid Unicode. If you want to have an error on invalid UTF-8,
 /// use the [`var`] function instead.
 ///
+/// # Errors
+///
+/// Returns `[None]` if the variable isn't set.
+/// May return `[None]` if the variable value contains the NUL character.
+///
 /// # Examples
 ///
 /// ```
@@ -249,7 +242,6 @@ pub fn var_os<K: AsRef<OsStr>>(key: K) -> Option<OsString> {
 
 fn _var_os(key: &OsStr) -> Option<OsString> {
     os_imp::getenv(key)
-        .unwrap_or_else(|e| panic!("failed to get environment variable `{:?}`: {}", key, e))
 }
 
 /// The error type for operations interacting with environment variables.

library/std/src/sys/hermit/os.rs

@@ -140,13 +140,8 @@ pub fn env() -> Env {
     }
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
-    unsafe {
-        match ENV.as_ref().unwrap().lock().unwrap().get_mut(k) {
-            Some(value) => Ok(Some(value.clone())),
-            None => Ok(None),
-        }
-    }
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    unsafe { ENV.as_ref().unwrap().lock().unwrap().get_mut(k).cloned() }
 }
 
 pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {

library/std/src/sys/sgx/os.rs

@@ -106,8 +106,8 @@ pub fn env() -> Env {
     get_env_store().map(|env| clone_to_vec(&env.lock().unwrap())).unwrap_or_default().into_iter()
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
-    Ok(get_env_store().and_then(|s| s.lock().unwrap().get(k).cloned()))
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    get_env_store().and_then(|s| s.lock().unwrap().get(k).cloned())
 }
 
 pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {

library/std/src/sys/unix/os.rs

@@ -532,19 +532,18 @@ pub fn env() -> Env {
     }
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
+pub fn getenv(k: &OsStr) -> Option<OsString> {
     // environment variables with a nul byte can't be set, so their value is
     // always None as well
-    let k = CString::new(k.as_bytes())?;
+    let k = CString::new(k.as_bytes()).ok()?;
     unsafe {
         let _guard = env_read_lock();
         let s = libc::getenv(k.as_ptr()) as *const libc::c_char;
-        let ret = if s.is_null() {
+        if s.is_null() {
             None
         } else {
             Some(OsStringExt::from_vec(CStr::from_ptr(s).to_bytes().to_vec()))
-        };
-        Ok(ret)
+        }
     }
 }
 

library/std/src/sys/unsupported/os.rs

@@ -76,8 +76,8 @@ pub fn env() -> Env {
     panic!("not supported on this platform")
 }
 
-pub fn getenv(_: &OsStr) -> io::Result<Option<OsString>> {
-    Ok(None)
+pub fn getenv(_: &OsStr) -> Option<OsString> {
+    None
 }
 
 pub fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> {

library/std/src/sys/wasi/os.rs

@@ -175,17 +175,16 @@ pub fn env() -> Env {
     }
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
-    let k = CString::new(k.as_bytes())?;
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    let k = CString::new(k.as_bytes()).ok()?;
     unsafe {
         let _guard = env_lock();
         let s = libc::getenv(k.as_ptr()) as *const libc::c_char;
-        let ret = if s.is_null() {
+        if s.is_null() {
             None
         } else {
             Some(OsStringExt::from_vec(CStr::from_ptr(s).to_bytes().to_vec()))
-        };
-        Ok(ret)
+        }
     }
 }
 

library/std/src/sys/windows/os.rs

@@ -253,22 +253,13 @@ pub fn chdir(p: &path::Path) -> io::Result<()> {
     cvt(unsafe { c::SetCurrentDirectoryW(p.as_ptr()) }).map(drop)
 }
 
-pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
-    let k = to_u16s(k)?;
-    let res = super::fill_utf16_buf(
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    let k = to_u16s(k).ok()?;
+    super::fill_utf16_buf(
         |buf, sz| unsafe { c::GetEnvironmentVariableW(k.as_ptr(), buf, sz) },
         |buf| OsStringExt::from_wide(buf),
-    );
-    match res {
-        Ok(value) => Ok(Some(value)),
-        Err(e) => {
-            if e.raw_os_error() == Some(c::ERROR_ENVVAR_NOT_FOUND as i32) {
-                Ok(None)
-            } else {
-                Err(e)
-            }
-        }
-    }
+    )
+    .ok()
 }
 
 pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {

src/test/ui/macros/issue-86082-option-env-invalid-char.rs

@@ -0,0 +1,10 @@
+// check-pass
+//
+// Regression test for issue #86082
+//
+// Checks that option_env! does not panic on receiving an invalid
+// environment variable name.
+
+fn main() {
+    option_env!("\0=");
+}