From patchwork Tue Feb 18 13:00:47 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andreas Hindborg X-Patchwork-Id: 13979794 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0E68C265CCE; Tue, 18 Feb 2025 13:01:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739883713; cv=none; b=e+PXZZUV+P8gbRrBCRUzjlXj3TpwBh4LqRRjGLVT3FBEThmKZANNsNyHbHAek0iVG8nMk1O0GLcWXjJih7v5tESlPkhzoEyV/fQTuFlYpuql78nSUaKWm80s2d5a/zMFWt1n99yeLLcA0kzduJdDLJgyTpZtCx24DebEBEqnXnc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739883713; c=relaxed/simple; bh=PCV7J741XsLI5Lf1r0pbxVGAOWX7VTsXjZUySE0EkOk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=fOPCsvu70u8Eld7kf2ACKQBqZhK54NrI1beW5tOsmiI1tCsbKofKoboDNT9TPcuuNeQen1Etrh3JhgyiI41g+d41KYpIhraeGWZaYwe6axunFV53n8DpGcgU5Xb77EaQI74xEg6ue5vSTEfzHY7M1SLBI2PmpXAnACKss0/Ac1E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lSYrJnp2; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lSYrJnp2" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2713C4CEE6; Tue, 18 Feb 2025 13:01:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739883712; bh=PCV7J741XsLI5Lf1r0pbxVGAOWX7VTsXjZUySE0EkOk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=lSYrJnp2FzLm0CpyLB6SBQIJlbIovOxZ8UGdoYQKdbrB3tBRFCJcZ0BrXUI4W4vUQ 6qlM1X5UFeTgpkjXz5Uaex4HimhnBGqBwnleIMFn59xDhE9tOpsymX0EP9R2VWKIC9 4WCphnmrK/4OykFt7/JconnZkC+JbKrzn0sHDaqgTxd9GR69Xtnvb/8m3jGYxIkeCd BUVQodJQQr+nJduQHQXe4jDmJk8Wkwa87RDD1I+zVRjlGcpv0fZSpYfkQFYGGquDNT jUImWr9tKeeqT6Md40pZKysxkgN/HN4jUZ9dJzwIaM4dIgjVWaD1WJqVynERC9Abt1 lbzaJ8xgkrJCg== From: Andreas Hindborg Date: Tue, 18 Feb 2025 14:00:47 +0100 Subject: [PATCH v7 5/6] rust: str: add radix prefixed integer parsing functions Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250218-module-params-v3-v7-5-5e1afabcac1b@kernel.org> References: <20250218-module-params-v3-v7-0-5e1afabcac1b@kernel.org> In-Reply-To: <20250218-module-params-v3-v7-0-5e1afabcac1b@kernel.org> To: Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Masahiro Yamada , Nathan Chancellor , Nicolas Schier , Luis Chamberlain Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Adam Bratschi-Kaye , linux-kbuild@vger.kernel.org, Petr Pavlu , Sami Tolvanen , Daniel Gomez , Simona Vetter , Greg KH , linux-modules@vger.kernel.org X-Mailer: b4 0.15-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=5711; i=a.hindborg@kernel.org; h=from:subject:message-id; bh=PCV7J741XsLI5Lf1r0pbxVGAOWX7VTsXjZUySE0EkOk=; b=owEBbQKS/ZANAwAIAeG4Gj55KGN3AcsmYgBntISHnjhpzfw5TGwhNAQrGg0Y+IeXAhe6Le9n/ 7o3cxrm2q2JAjMEAAEIAB0WIQQSwflHVr98KhXWwBLhuBo+eShjdwUCZ7SEhwAKCRDhuBo+eShj d0V2EACQd+cmGOqcfkVRFMfEJ3T9SlONnRMUUxBpd0QLiogLrMFbw6uV+eamk/lqv8rs41TwPr9 o/KPBKzzTZkegvsdel3rElRuMXEgV1rV+RUrOiJY7828nLlPlUKrRjpHLNK1Yc08KgWtE72Gu4I 6QzzfRRXaaxOzVGWkVmdjdCBbmCXQU03aE4orNzFP+DpUGPFGzzdGvJKFHjj4o4W1jrKxLG8ACi jXCLjawwbQL6nJN23aiVOtnvuPSXOTRCukE7AdA4PVsySxbmhy/cIUh1DxAGJJAY8NwhEtLazV2 AnBQAmLyAQ33WNVANDCBm761fPCV+OkLeAAMTg9Gv46Vl+xMAoGalfIP0mE6eJ61w/QN8hZvo7r Md0Jfa47nSnRqt78pReIhL6s1QrOwevIJ+bgb/2qCRPlX8hIpEYnFOUHBqvvvQC0F+Sd7SoFeBu SSMz5EsdcP2P1FeTMRk8FElUjQPgRjwlXGoMzyf6duOgMx9b9ToegGOAvfYKuAldARKaUgWVEvi jlXZQteAGjBbqUsNQCP/yNIYbcdxq6pNR5eF170q6rcr5rQ06a1sBs9pqjLNefggLBSeEgGPsVx HCG9Lysdg3jqd/s0Fq8rYq//CTY78rmbVLrEJlo/yaBVM1qMaizOaqhIEbLoW5pq4u1/X58O//R 7pZksyzWcCgJDtg== X-Developer-Key: i=a.hindborg@kernel.org; a=openpgp; fpr=3108C10F46872E248D1FB221376EB100563EF7A7 Add the trait `ParseInt` for parsing string representations of integers where the string representations are optionally prefixed by a radix specifier. Implement the trait for the primitive integer types. Signed-off-by: Andreas Hindborg --- rust/kernel/str.rs | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs index db272d2198fcc..8b0d814b47f52 100644 --- a/rust/kernel/str.rs +++ b/rust/kernel/str.rs @@ -945,3 +945,121 @@ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { macro_rules! fmt { ($($f:tt)*) => ( core::format_args!($($f)*) ) } + +pub mod parse_int { + //! Integer parsing functions for parsing signed and unsigned integers + //! potentially prefixed with `0x`, `0o`, or `0b`. + + use crate::prelude::*; + use crate::str::BStr; + use core::ops::Deref; + + /// Trait that allows parsing a [`&BStr`] to an integer with a radix. + /// + /// [`&BStr`]: kernel::str::BStr + // This is required because the `from_str_radix` function on the primitive + // integer types is not part of any trait. + pub trait FromStrRadix: Sized { + /// Parse `src` to `Self` using radix `radix`. + fn from_str_radix(src: &BStr, radix: u32) -> Result; + } + + /// Extract the radix from an integer literal optionally prefixed with + /// one of `0x`, `0X`, `0o`, `0O`, `0b`, `0B`, `0`. + fn strip_radix(src: &BStr) -> (u32, &BStr) { + match src.deref() { + [b'0', b'x' | b'X', rest @ ..] => (16, rest.as_ref()), + [b'0', b'o' | b'O', rest @ ..] => (8, rest.as_ref()), + [b'0', b'b' | b'B', rest @ ..] => (2, rest.as_ref()), + // NOTE: We are including the leading zero to be able to parse + // literal 0 here. If we removed it as a radix prefix, we would not + // be able to parse `0`. + [b'0', ..] => (8, src), + _ => (10, src), + } + } + + /// Trait for parsing string representations of integers. + /// + /// Strings beginning with `0x`, `0o`, or `0b` are parsed as hex, octal, or + /// binary respectively. Strings beginning with `0` otherwise are parsed as + /// octal. Anything else is parsed as decimal. A leading `+` or `-` is also + /// permitted. Any string parsed by [`kstrtol()`] or [`kstrtoul()`] will be + /// successfully parsed. + /// + /// [`kstrtol()`]: https://www.kernel.org/doc/html/latest/core-api/kernel-api.html#c.kstrtol + /// [`kstrtoul()`]: https://www.kernel.org/doc/html/latest/core-api/kernel-api.html#c.kstrtoul + /// + /// # Example + /// ``` + /// use kernel::str::parse_int::ParseInt; + /// use kernel::b_str; + /// + /// assert_eq!(Ok(0), u8::from_str(b_str!("0"))); + /// + /// assert_eq!(Ok(0xa2u8), u8::from_str(b_str!("0xa2"))); + /// assert_eq!(Ok(-0xa2i32), i32::from_str(b_str!("-0xa2"))); + /// + /// assert_eq!(Ok(-0o57i8), i8::from_str(b_str!("-0o57"))); + /// assert_eq!(Ok(0o57i8), i8::from_str(b_str!("057"))); + /// + /// assert_eq!(Ok(0b1001i16), i16::from_str(b_str!("0b1001"))); + /// assert_eq!(Ok(-0b1001i16), i16::from_str(b_str!("-0b1001"))); + /// + /// assert_eq!(Ok(127), i8::from_str(b_str!("127"))); + /// assert!(i8::from_str(b_str!("128")).is_err()); + /// assert_eq!(Ok(-128), i8::from_str(b_str!("-128"))); + /// assert!(i8::from_str(b_str!("-129")).is_err()); + /// assert_eq!(Ok(255), u8::from_str(b_str!("255"))); + /// assert!(u8::from_str(b_str!("256")).is_err()); + /// ``` + pub trait ParseInt: FromStrRadix + TryFrom { + /// Parse a string according to the description in [`Self`]. + fn from_str(src: &BStr) -> Result { + match src.deref() { + [b'-', rest @ ..] => { + let (radix, digits) = strip_radix(rest.as_ref()); + // 2's complement values range from -2^(b-1) to 2^(b-1)-1. + // So if we want to parse negative numbers as positive and + // later multiply by -1, we have to parse into a larger + // integer. We choose i128 as sufficiently large. + let val = i128::from_str_radix( + core::str::from_utf8(digits).map_err(|_| EINVAL)?, + radix, + ) + .map_err(|_| EINVAL)?; + let val = -val; + val.try_into().map_err(|_| EINVAL) + } + _ => { + let (radix, digits) = strip_radix(src); + Self::from_str_radix(digits, radix).map_err(|_| EINVAL) + } + } + } + } + + macro_rules! impl_parse_int { + ($ty:ty) => { + impl FromStrRadix for $ty { + fn from_str_radix(src: &BStr, radix: u32) -> Result { + <$ty>::from_str_radix(core::str::from_utf8(src).map_err(|_| EINVAL)?, radix) + .map_err(|_| EINVAL) + } + } + + impl ParseInt for $ty {} + }; + } + + impl_parse_int!(i8); + impl_parse_int!(u8); + impl_parse_int!(i16); + impl_parse_int!(u16); + impl_parse_int!(i32); + impl_parse_int!(u32); + impl_parse_int!(i64); + impl_parse_int!(u64); + impl_parse_int!(isize); + impl_parse_int!(usize); +}