/rust/registry/src/index.crates.io-6f17d22bba15001f/getrandom-0.3.3/src/error.rs

Source (jump to first uncovered line)
#[cfg(feature = "std")]
extern crate std;

use core::fmt;

// This private alias mirrors `std::io::RawOsError`:
// https://doc.rust-lang.org/std/io/type.RawOsError.html)
cfg_if::cfg_if!(
    if #[cfg(target_os = "uefi")] {
        // See the UEFI spec for more information:
        // https://uefi.org/specs/UEFI/2.10/Apx_D_Status_Codes.html
        type RawOsError = usize;
        type NonZeroRawOsError = core::num::NonZeroUsize;
        const UEFI_ERROR_FLAG: RawOsError = 1 << (RawOsError::BITS - 1);
    } else {
        type RawOsError = i32;
        type NonZeroRawOsError = core::num::NonZeroI32;
    }
);

/// A small and `no_std` compatible error type
///
/// The [`Error::raw_os_error()`] will indicate if the error is from the OS, and
/// if so, which error code the OS gave the application. If such an error is
/// encountered, please consult with your system documentation.
///
/// *If this crate's `"std"` Cargo feature is enabled*, then:
/// - [`getrandom::Error`][Error] implements
///   [`std::error::Error`](https://doc.rust-lang.org/std/error/trait.Error.html)
/// - [`std::io::Error`](https://doc.rust-lang.org/std/io/struct.Error.html) implements
///   [`From<getrandom::Error>`](https://doc.rust-lang.org/std/convert/trait.From.html).

// note: on non-UEFI targets OS errors are represented as negative integers,
// while on UEFI targets OS errors have the highest bit set to 1.
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct Error(NonZeroRawOsError);

impl Error {
    /// This target/platform is not supported by `getrandom`.
    pub const UNSUPPORTED: Error = Self::new_internal(0);
    /// The platform-specific `errno` returned a non-positive value.
    pub const ERRNO_NOT_POSITIVE: Error = Self::new_internal(1);
    /// Encountered an unexpected situation which should not happen in practice.
    pub const UNEXPECTED: Error = Self::new_internal(2);

    /// Internal errors can be in the range of 2^16..2^17
    const INTERNAL_START: RawOsError = 1 << 16;
    /// Custom errors can be in the range of 2^17..(2^17 + 2^16)
    const CUSTOM_START: RawOsError = 1 << 17;

    /// Creates a new instance of an `Error` from a negative error code.
    #[cfg(not(target_os = "uefi"))]
    #[allow(dead_code)]
    pub(super) fn from_neg_error_code(code: RawOsError) -> Self {
        if code < 0 {
            let code = NonZeroRawOsError::new(code).expect("`code` is negative");
            Self(code)
        } else {
            Error::UNEXPECTED
        }
    }

    /// Creates a new instance of an `Error` from an UEFI error code.
    #[cfg(target_os = "uefi")]
    #[allow(dead_code)]
    pub(super) fn from_uefi_code(code: RawOsError) -> Self {
        if code & UEFI_ERROR_FLAG != 0 {
            let code = NonZeroRawOsError::new(code).expect("The highest bit of `code` is set to 1");
            Self(code)
        } else {
            Self::UNEXPECTED
        }
    }

    /// Extract the raw OS error code (if this error came from the OS)
    ///
    /// This method is identical to [`std::io::Error::raw_os_error()`][1], except
    /// that it works in `no_std` contexts. On most targets this method returns
    /// `Option<i32>`, but some platforms (e.g. UEFI) may use a different primitive
    /// type like `usize`. Consult with the [`RawOsError`] docs for more information.
    ///
    /// If this method returns `None`, the error value can still be formatted via
    /// the `Display` implementation.
    ///
    /// [1]: https://doc.rust-lang.org/std/io/struct.Error.html#method.raw_os_error
    /// [`RawOsError`]: https://doc.rust-lang.org/std/io/type.RawOsError.html
    #[inline]
    pub fn raw_os_error(self) -> Option<RawOsError> {
        let code = self.0.get();

        // note: in this method we need to cover only backends which rely on
        // `Error::{from_error_code, from_errno, from_uefi_code}` methods,
        // on all other backends this method always returns `None`.

        #[cfg(target_os = "uefi")]
        {
            if code & UEFI_ERROR_FLAG != 0 {
                Some(code)
            } else {
                None
            }
        }

        #[cfg(not(target_os = "uefi"))]
        {
            // On most targets `std` expects positive error codes while retrieving error strings:
            // - `libc`-based targets use `strerror_r` which expects positive error codes.
            // - Hermit relies on the `hermit-abi` crate, which expects positive error codes:
            //   https://docs.rs/hermit-abi/0.4.0/src/hermit_abi/errno.rs.html#400-532
            // - WASIp1 uses the same conventions as `libc`:
            //   https://github.com/rust-lang/rust/blob/1.85.0/library/std/src/sys/pal/wasi/os.rs#L57-L67
            //
            // The only exception is Solid, `std` expects negative system error codes, see:
            // https://github.com/rust-lang/rust/blob/1.85.0/library/std/src/sys/pal/solid/error.rs#L5-L31
            if code >= 0 {
                None
            } else if cfg!(not(target_os = "solid_asp3")) {
                code.checked_neg()
            } else {
                Some(code)
            }
        }
    }

    /// Creates a new instance of an `Error` from a particular custom error code.
    pub const fn new_custom(n: u16) -> Error {
        // SAFETY: code > 0 as CUSTOM_START > 0 and adding `n` won't overflow `RawOsError`.
        let code = Error::CUSTOM_START + (n as RawOsError);
        Error(unsafe { NonZeroRawOsError::new_unchecked(code) })
    }

    /// Creates a new instance of an `Error` from a particular internal error code.
    pub(crate) const fn new_internal(n: u16) -> Error {
        // SAFETY: code > 0 as INTERNAL_START > 0 and adding `n` won't overflow `RawOsError`.
        let code = Error::INTERNAL_START + (n as RawOsError);
        Error(unsafe { NonZeroRawOsError::new_unchecked(code) })
    }

    fn internal_desc(&self) -> Option<&'static str> {
        let desc = match *self {
            Error::UNSUPPORTED => "getrandom: this target is not supported",
            Error::ERRNO_NOT_POSITIVE => "errno: did not return a positive value",
            Error::UNEXPECTED => "unexpected situation",
            #[cfg(any(
                target_os = "ios",
                target_os = "visionos",
                target_os = "watchos",
                target_os = "tvos",
            ))]
            Error::IOS_RANDOM_GEN => "SecRandomCopyBytes: iOS Security framework failure",
            #[cfg(all(windows, target_vendor = "win7"))]
            Error::WINDOWS_RTL_GEN_RANDOM => "RtlGenRandom: Windows system function failure",
            #[cfg(all(feature = "wasm_js", getrandom_backend = "wasm_js"))]
            Error::WEB_CRYPTO => "Web Crypto API is unavailable",
            #[cfg(target_os = "vxworks")]
            Error::VXWORKS_RAND_SECURE => "randSecure: VxWorks RNG module is not initialized",

            #[cfg(any(
                getrandom_backend = "rdrand",
                all(target_arch = "x86_64", target_env = "sgx")
            ))]
            Error::FAILED_RDRAND => "RDRAND: failed multiple times: CPU issue likely",
            #[cfg(any(
                getrandom_backend = "rdrand",
                all(target_arch = "x86_64", target_env = "sgx")
            ))]
            Error::NO_RDRAND => "RDRAND: instruction not supported",

            #[cfg(getrandom_backend = "rndr")]
            Error::RNDR_FAILURE => "RNDR: Could not generate a random number",
            #[cfg(getrandom_backend = "rndr")]
            Error::RNDR_NOT_AVAILABLE => "RNDR: Register not supported",
            _ => return None,
        };
        Some(desc)
    }
}

impl fmt::Debug for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        let mut dbg = f.debug_struct("Error");
        if let Some(errno) = self.raw_os_error() {
            dbg.field("os_error", &errno);
            #[cfg(feature = "std")]
            dbg.field("description", &std::io::Error::from_raw_os_error(errno));
        } else if let Some(desc) = self.internal_desc() {
            dbg.field("internal_code", &self.0.get());
            dbg.field("description", &desc);
        } else {
            dbg.field("unknown_code", &self.0.get());
        }
        dbg.finish()
    }
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        if let Some(errno) = self.raw_os_error() {
            cfg_if! {
                if #[cfg(feature = "std")] {
                    std::io::Error::from_raw_os_error(errno).fmt(f)
                } else {
                    write!(f, "OS Error: {}", errno)
                }
            }
        } else if let Some(desc) = self.internal_desc() {
            f.write_str(desc)
        } else {
            write!(f, "Unknown Error: {}", self.0.get())
        }
    }
}

Coverage Report

Created: 2025-07-11 06:22

Line	Count	Source (jump to first uncovered line)
1		#[cfg(feature = "std")]
2		extern crate std;
3
4		use core::fmt;
5
6		// This private alias mirrors `std::io::RawOsError`:
7		// https://doc.rust-lang.org/std/io/type.RawOsError.html)
8		cfg_if::cfg_if!(
9		if #[cfg(target_os = "uefi")] {
10		// See the UEFI spec for more information:
11		// https://uefi.org/specs/UEFI/2.10/Apx_D_Status_Codes.html
12		type RawOsError = usize;
13		type NonZeroRawOsError = core::num::NonZeroUsize;
14		const UEFI_ERROR_FLAG: RawOsError = 1 << (RawOsError::BITS - 1);
15		} else {
16		type RawOsError = i32;
17		type NonZeroRawOsError = core::num::NonZeroI32;
18		}
19		);
20
21		/// A small and `no_std` compatible error type
22		///
23		/// The [`Error::raw_os_error()`] will indicate if the error is from the OS, and
24		/// if so, which error code the OS gave the application. If such an error is
25		/// encountered, please consult with your system documentation.
26		///
27		/// If this crate's `"std"` Cargo feature is enabled, then:
28		/// - [`getrandom::Error`][Error] implements
29		/// [`std::error::Error`](https://doc.rust-lang.org/std/error/trait.Error.html)
30		/// - [`std::io::Error`](https://doc.rust-lang.org/std/io/struct.Error.html) implements
31		/// [`From<getrandom::Error>`](https://doc.rust-lang.org/std/convert/trait.From.html).
32
33		// note: on non-UEFI targets OS errors are represented as negative integers,
34		// while on UEFI targets OS errors have the highest bit set to 1.
35		#[derive(Copy, Clone, Eq, PartialEq)]
36		pub struct Error(NonZeroRawOsError);
37
38		impl Error {
39		/// This target/platform is not supported by `getrandom`.
40		pub const UNSUPPORTED: Error = Self::new_internal(0);
41		/// The platform-specific `errno` returned a non-positive value.
42		pub const ERRNO_NOT_POSITIVE: Error = Self::new_internal(1);
43		/// Encountered an unexpected situation which should not happen in practice.
44		pub const UNEXPECTED: Error = Self::new_internal(2);
45
46		/// Internal errors can be in the range of 2^16..2^17
47		const INTERNAL_START: RawOsError = 1 << 16;
48		/// Custom errors can be in the range of 2^17..(2^17 + 2^16)
49		const CUSTOM_START: RawOsError = 1 << 17;
50
51		/// Creates a new instance of an `Error` from a negative error code.
52		#[cfg(not(target_os = "uefi"))]
53		#[allow(dead_code)]
54	0	pub(super) fn from_neg_error_code(code: RawOsError) -> Self {
55	0	if code < 0 {
56	0	let code = NonZeroRawOsError::new(code).expect("`code` is negative");
57	0	Self(code)
58		} else {
59	0	Error::UNEXPECTED
60		}
61	0	}
62
63		/// Creates a new instance of an `Error` from an UEFI error code.
64		#[cfg(target_os = "uefi")]
65		#[allow(dead_code)]
66		pub(super) fn from_uefi_code(code: RawOsError) -> Self {
67		if code & UEFI_ERROR_FLAG != 0 {
68		let code = NonZeroRawOsError::new(code).expect("The highest bit of `code` is set to 1");
69		Self(code)
70		} else {
71		Self::UNEXPECTED
72		}
73		}
74
75		/// Extract the raw OS error code (if this error came from the OS)
76		///
77		/// This method is identical to [`std::io::Error::raw_os_error()`][1], except
78		/// that it works in `no_std` contexts. On most targets this method returns
79		/// `Option<i32>`, but some platforms (e.g. UEFI) may use a different primitive
80		/// type like `usize`. Consult with the [`RawOsError`] docs for more information.
81		///
82		/// If this method returns `None`, the error value can still be formatted via
83		/// the `Display` implementation.
84		///
85		/// [1]: https://doc.rust-lang.org/std/io/struct.Error.html#method.raw_os_error
86		/// [`RawOsError`]: https://doc.rust-lang.org/std/io/type.RawOsError.html
87		#[inline]
88	0	pub fn raw_os_error(self) -> Option<RawOsError> {
89	0	let code = self.0.get();
90	0
91	0	// note: in this method we need to cover only backends which rely on
92	0	// `Error::{from_error_code, from_errno, from_uefi_code}` methods,
93	0	// on all other backends this method always returns `None`.
94	0
95	0	#[cfg(target_os = "uefi")]
96	0	{
97	0	if code & UEFI_ERROR_FLAG != 0 {
98	0	Some(code)
99	0	} else {
100	0	None
101	0	}
102	0	}
103	0
104	0	#[cfg(not(target_os = "uefi"))]
105	0	{
106	0	// On most targets `std` expects positive error codes while retrieving error strings:
107	0	// - `libc`-based targets use `strerror_r` which expects positive error codes.
108	0	// - Hermit relies on the `hermit-abi` crate, which expects positive error codes:
109	0	// https://docs.rs/hermit-abi/0.4.0/src/hermit_abi/errno.rs.html#400-532
110	0	// - WASIp1 uses the same conventions as `libc`:
111	0	// https://github.com/rust-lang/rust/blob/1.85.0/library/std/src/sys/pal/wasi/os.rs#L57-L67
112	0	//
113	0	// The only exception is Solid, `std` expects negative system error codes, see:
114	0	// https://github.com/rust-lang/rust/blob/1.85.0/library/std/src/sys/pal/solid/error.rs#L5-L31
115	0	if code >= 0 {
116	0	None
117	0	} else if cfg!(not(target_os = "solid_asp3")) {
118	0	code.checked_neg()
119		} else {
120	0	Some(code)
121		}
122		}
123	0	} Unexecuted instantiation: <getrandom::error::Error>::raw_os_error Unexecuted instantiation: <getrandom::error::Error>::raw_os_error
124
125		/// Creates a new instance of an `Error` from a particular custom error code.
126	0	pub const fn new_custom(n: u16) -> Error {
127	0	// SAFETY: code > 0 as CUSTOM_START > 0 and adding `n` won't overflow `RawOsError`.
128	0	let code = Error::CUSTOM_START + (n as RawOsError);
129	0	Error(unsafe { NonZeroRawOsError::new_unchecked(code) })
130	0	}
131
132		/// Creates a new instance of an `Error` from a particular internal error code.
133	0	pub(crate) const fn new_internal(n: u16) -> Error {
134	0	// SAFETY: code > 0 as INTERNAL_START > 0 and adding `n` won't overflow `RawOsError`.
135	0	let code = Error::INTERNAL_START + (n as RawOsError);
136	0	Error(unsafe { NonZeroRawOsError::new_unchecked(code) })
137	0	}
138
139	0	fn internal_desc(&self) -> Option<&'static str> {
140	0	let desc = match *self {
141	0	Error::UNSUPPORTED => "getrandom: this target is not supported",
142	0	Error::ERRNO_NOT_POSITIVE => "errno: did not return a positive value",
143	0	Error::UNEXPECTED => "unexpected situation",
144		#[cfg(any(
145		target_os = "ios",
146		target_os = "visionos",
147		target_os = "watchos",
148		target_os = "tvos",
149		))]
150		Error::IOS_RANDOM_GEN => "SecRandomCopyBytes: iOS Security framework failure",
151		#[cfg(all(windows, target_vendor = "win7"))]
152		Error::WINDOWS_RTL_GEN_RANDOM => "RtlGenRandom: Windows system function failure",
153		#[cfg(all(feature = "wasm_js", getrandom_backend = "wasm_js"))]
154		Error::WEB_CRYPTO => "Web Crypto API is unavailable",
155		#[cfg(target_os = "vxworks")]
156		Error::VXWORKS_RAND_SECURE => "randSecure: VxWorks RNG module is not initialized",
157
158		#[cfg(any(
159		getrandom_backend = "rdrand",
160		all(target_arch = "x86_64", target_env = "sgx")
161		))]
162		Error::FAILED_RDRAND => "RDRAND: failed multiple times: CPU issue likely",
163		#[cfg(any(
164		getrandom_backend = "rdrand",
165		all(target_arch = "x86_64", target_env = "sgx")
166		))]
167		Error::NO_RDRAND => "RDRAND: instruction not supported",
168
169		#[cfg(getrandom_backend = "rndr")]
170		Error::RNDR_FAILURE => "RNDR: Could not generate a random number",
171		#[cfg(getrandom_backend = "rndr")]
172		Error::RNDR_NOT_AVAILABLE => "RNDR: Register not supported",
173	0	_ => return None,
174		};
175	0	Some(desc)
176	0	}
177		}
178
179		impl fmt::Debug for Error {
180	0	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
181	0	let mut dbg = f.debug_struct("Error");
182	0	if let Some(errno) = self.raw_os_error() {
183	0	dbg.field("os_error", &errno);
184	0	#[cfg(feature = "std")]
185	0	dbg.field("description", &std::io::Error::from_raw_os_error(errno));
186	0	} else if let Some(desc) = self.internal_desc() {
187	0	dbg.field("internal_code", &self.0.get());
188	0	dbg.field("description", &desc);
189	0	} else {
190	0	dbg.field("unknown_code", &self.0.get());
191	0	}
192	0	dbg.finish()
193	0	}
194		}
195
196		impl fmt::Display for Error {
197	0	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
198	0	if let Some(errno) = self.raw_os_error() {
199		cfg_if! {
200		if #[cfg(feature = "std")] {
201	0	std::io::Error::from_raw_os_error(errno).fmt(f)
202		} else {
203		write!(f, "OS Error: {}", errno)
204		}
205		}
206	0	} else if let Some(desc) = self.internal_desc() {
207	0	f.write_str(desc)
208		} else {
209	0	write!(f, "Unknown Error: {}", self.0.get())
210		}
211	0	}
212		}