2019-04-07 17:44:10 +00:00
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use crate::utils::{last_path_segment, paths, snippet, span_lint, span_lint_and_then, sugg};
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2018-11-27 20:14:15 +00:00
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use if_chain::if_chain;
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2018-12-29 15:04:45 +00:00
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use rustc::hir::*;
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use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
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use rustc::ty::{self, Ty};
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2019-04-08 20:43:55 +00:00
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use rustc::{declare_lint_pass, declare_tool_lint};
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2018-12-29 15:04:45 +00:00
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use rustc_errors::Applicability;
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2018-11-27 20:14:15 +00:00
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use std::borrow::Cow;
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2018-12-29 15:04:45 +00:00
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use syntax::ast;
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2015-11-11 14:28:31 +00:00
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for transmutes that can't ever be correct on any
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/// architecture.
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///
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/// **Why is this bad?** It's basically guaranteed to be undefined behaviour.
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///
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/// **Known problems:** When accessing C, users might want to store pointer
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/// sized objects in `extradata` arguments to save an allocation.
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///
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/// **Example:**
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2019-03-05 22:23:50 +00:00
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/// ```ignore
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2019-03-05 16:50:33 +00:00
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/// let ptr: *const T = core::intrinsics::transmute('x')
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/// ```
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2016-06-28 12:08:08 +00:00
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pub WRONG_TRANSMUTE,
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2018-03-28 13:24:26 +00:00
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correctness,
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2016-06-28 12:08:08 +00:00
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"transmutes that are confusing at best, undefined behaviour at worst and always useless"
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}
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for transmutes to the original type of the object
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/// and transmutes that could be a cast.
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///
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/// **Why is this bad?** Readability. The code tricks people into thinking that
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/// something complex is going on.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// core::intrinsics::transmute(t) // where the result type is the same as `t`'s
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/// ```
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2015-11-11 14:28:31 +00:00
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pub USELESS_TRANSMUTE,
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2018-03-28 13:24:26 +00:00
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complexity,
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2016-06-28 12:08:08 +00:00
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"transmutes that have the same to and from types or could be a cast/coercion"
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2015-11-11 14:28:31 +00:00
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}
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for transmutes between a type `T` and `*T`.
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///
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/// **Why is this bad?** It's easy to mistakenly transmute between a type and a
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/// pointer to that type.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// core::intrinsics::transmute(t) // where the result type is the same as
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/// // `*t` or `&t`'s
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/// ```
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2016-03-24 22:48:38 +00:00
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pub CROSSPOINTER_TRANSMUTE,
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2018-03-28 13:24:26 +00:00
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complexity,
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2016-03-24 22:48:38 +00:00
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"transmutes that have to or from types that are a pointer to the other"
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}
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for transmutes from a pointer to a reference.
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///
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/// **Why is this bad?** This can always be rewritten with `&` and `*`.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// let _: &T = std::mem::transmute(p); // where p: *const T
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///
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/// // can be written:
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/// let _: &T = &*p;
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/// ```
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2016-03-25 22:22:17 +00:00
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pub TRANSMUTE_PTR_TO_REF,
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2018-03-28 13:24:26 +00:00
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complexity,
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2016-03-25 22:22:17 +00:00
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"transmutes from a pointer to a reference type"
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}
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for transmutes from an integer to a `char`.
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///
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/// **Why is this bad?** Not every integer is a Unicode scalar value.
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///
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/// **Known problems:**
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/// - [`from_u32`] which this lint suggests using is slower than `transmute`
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/// as it needs to validate the input.
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/// If you are certain that the input is always a valid Unicode scalar value,
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/// use [`from_u32_unchecked`] which is as fast as `transmute`
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/// but has a semantically meaningful name.
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/// - You might want to handle `None` returned from [`from_u32`] instead of calling `unwrap`.
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///
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/// [`from_u32`]: https://doc.rust-lang.org/std/char/fn.from_u32.html
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/// [`from_u32_unchecked`]: https://doc.rust-lang.org/std/char/fn.from_u32_unchecked.html
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///
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/// **Example:**
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/// ```rust
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/// let _: char = std::mem::transmute(x); // where x: u32
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///
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/// // should be:
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/// let _ = std::char::from_u32(x).unwrap();
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/// ```
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2017-10-02 15:23:24 +00:00
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pub TRANSMUTE_INT_TO_CHAR,
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2018-03-28 13:24:26 +00:00
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complexity,
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2017-10-02 15:23:24 +00:00
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"transmutes from an integer to a `char`"
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}
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for transmutes from a `&[u8]` to a `&str`.
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///
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/// **Why is this bad?** Not every byte slice is a valid UTF-8 string.
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///
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/// **Known problems:**
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/// - [`from_utf8`] which this lint suggests using is slower than `transmute`
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/// as it needs to validate the input.
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/// If you are certain that the input is always a valid UTF-8,
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/// use [`from_utf8_unchecked`] which is as fast as `transmute`
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/// but has a semantically meaningful name.
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/// - You might want to handle errors returned from [`from_utf8`] instead of calling `unwrap`.
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///
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/// [`from_utf8`]: https://doc.rust-lang.org/std/str/fn.from_utf8.html
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/// [`from_utf8_unchecked`]: https://doc.rust-lang.org/std/str/fn.from_utf8_unchecked.html
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///
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/// **Example:**
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/// ```rust
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/// let _: &str = std::mem::transmute(b); // where b: &[u8]
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///
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/// // should be:
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/// let _ = std::str::from_utf8(b).unwrap();
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/// ```
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2017-10-29 01:27:45 +00:00
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pub TRANSMUTE_BYTES_TO_STR,
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2018-03-28 13:24:26 +00:00
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complexity,
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2017-10-29 01:27:45 +00:00
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"transmutes from a `&[u8]` to a `&str`"
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}
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for transmutes from an integer to a `bool`.
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///
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/// **Why is this bad?** This might result in an invalid in-memory representation of a `bool`.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// let _: bool = std::mem::transmute(x); // where x: u8
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///
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/// // should be:
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/// let _: bool = x != 0;
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/// ```
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2017-10-02 15:23:24 +00:00
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pub TRANSMUTE_INT_TO_BOOL,
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2018-03-28 13:24:26 +00:00
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complexity,
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2017-10-02 15:23:24 +00:00
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"transmutes from an integer to a `bool`"
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}
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2018-03-28 13:24:26 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for transmutes from an integer to a float.
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///
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/// **Why is this bad?** Transmutes are dangerous and error-prone, whereas `from_bits` is intuitive
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/// and safe.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// let _: f32 = std::mem::transmute(x); // where x: u32
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///
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/// // should be:
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/// let _: f32 = f32::from_bits(x);
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/// ```
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2017-10-02 15:23:24 +00:00
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pub TRANSMUTE_INT_TO_FLOAT,
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2018-03-28 13:24:26 +00:00
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complexity,
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2017-10-02 15:23:24 +00:00
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"transmutes from an integer to a float"
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}
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2018-04-11 09:17:59 +00:00
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declare_clippy_lint! {
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2019-03-05 16:50:33 +00:00
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/// **What it does:** Checks for transmutes from a pointer to a pointer, or
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/// from a reference to a reference.
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///
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/// **Why is this bad?** Transmutes are dangerous, and these can instead be
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/// written as casts.
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///
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/// **Known problems:** None.
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///
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/// **Example:**
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/// ```rust
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/// let ptr = &1u32 as *const u32;
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/// unsafe {
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/// // pointer-to-pointer transmute
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/// let _: *const f32 = std::mem::transmute(ptr);
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/// // ref-ref transmute
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/// let _: &f32 = std::mem::transmute(&1u32);
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/// }
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/// // These can be respectively written:
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/// let _ = ptr as *const f32
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/// let _ = unsafe{ &*(&1u32 as *const u32 as *const f32) };
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/// ```
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2018-04-11 09:17:59 +00:00
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pub TRANSMUTE_PTR_TO_PTR,
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complexity,
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2018-05-14 17:24:31 +00:00
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"transmutes from a pointer to a pointer / a reference to a reference"
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2018-04-11 09:17:59 +00:00
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}
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2019-04-08 20:43:55 +00:00
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declare_lint_pass!(Transmute => [
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CROSSPOINTER_TRANSMUTE,
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TRANSMUTE_PTR_TO_REF,
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TRANSMUTE_PTR_TO_PTR,
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USELESS_TRANSMUTE,
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WRONG_TRANSMUTE,
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TRANSMUTE_INT_TO_CHAR,
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TRANSMUTE_BYTES_TO_STR,
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TRANSMUTE_INT_TO_BOOL,
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TRANSMUTE_INT_TO_FLOAT,
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]);
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2015-11-11 14:28:31 +00:00
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2016-12-07 12:13:40 +00:00
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impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Transmute {
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2019-01-13 15:19:02 +00:00
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#[allow(clippy::similar_names, clippy::too_many_lines)]
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2016-12-07 12:13:40 +00:00
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fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, e: &'tcx Expr) {
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2018-07-12 07:30:57 +00:00
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if let ExprKind::Call(ref path_expr, ref args) = e.node {
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if let ExprKind::Path(ref qpath) = path_expr.node {
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2019-05-04 00:03:12 +00:00
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if let Some(def_id) = cx.tables.qpath_res(qpath, path_expr.hir_id).opt_def_id() {
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2019-04-07 17:44:10 +00:00
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if cx.match_def_path(def_id, &paths::TRANSMUTE) {
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2017-09-12 12:26:40 +00:00
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let from_ty = cx.tables.expr_ty(&args[0]);
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let to_ty = cx.tables.expr_ty(e);
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2015-11-11 14:28:31 +00:00
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2017-09-12 12:26:40 +00:00
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match (&from_ty.sty, &to_ty.sty) {
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_ if from_ty == to_ty => span_lint(
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cx,
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USELESS_TRANSMUTE,
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e.span,
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&format!("transmute from a type (`{}`) to itself", from_ty),
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),
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2018-08-22 21:34:52 +00:00
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(&ty::Ref(_, rty, rty_mutbl), &ty::RawPtr(ptr_ty)) => span_lint_and_then(
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2017-09-12 12:26:40 +00:00
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cx,
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USELESS_TRANSMUTE,
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e.span,
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"transmute from a reference to a pointer",
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2018-11-27 20:14:15 +00:00
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|db| {
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if let Some(arg) = sugg::Sugg::hir_opt(cx, &args[0]) {
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let rty_and_mut = ty::TypeAndMut {
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ty: rty,
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mutbl: rty_mutbl,
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};
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2018-05-11 06:37:48 +00:00
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2018-11-27 20:14:15 +00:00
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let sugg = if ptr_ty == rty_and_mut {
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arg.as_ty(to_ty)
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} else {
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arg.as_ty(cx.tcx.mk_ptr(rty_and_mut)).as_ty(to_ty)
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};
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2016-06-27 14:12:48 +00:00
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2019-01-27 12:34:23 +00:00
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db.span_suggestion(e.span, "try", sugg.to_string(), Applicability::Unspecified);
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2018-11-27 20:14:15 +00:00
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}
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2017-09-12 12:26:40 +00:00
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},
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),
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2018-11-27 20:14:15 +00:00
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(&ty::Int(_), &ty::RawPtr(_)) | (&ty::Uint(_), &ty::RawPtr(_)) => span_lint_and_then(
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cx,
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USELESS_TRANSMUTE,
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e.span,
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"transmute from an integer to a pointer",
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|db| {
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if let Some(arg) = sugg::Sugg::hir_opt(cx, &args[0]) {
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2019-01-27 12:33:56 +00:00
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db.span_suggestion(
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2018-09-18 15:07:54 +00:00
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e.span,
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"try",
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arg.as_ty(&to_ty.to_string()).to_string(),
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Applicability::Unspecified,
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);
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2018-11-27 20:14:15 +00:00
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}
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},
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),
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(&ty::Float(_), &ty::Ref(..))
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| (&ty::Float(_), &ty::RawPtr(_))
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| (&ty::Char, &ty::Ref(..))
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| (&ty::Char, &ty::RawPtr(_)) => span_lint(
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2017-09-12 12:26:40 +00:00
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cx,
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WRONG_TRANSMUTE,
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e.span,
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&format!("transmute from a `{}` to a pointer", from_ty),
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2017-09-05 09:33:04 +00:00
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),
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2018-08-22 21:34:52 +00:00
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(&ty::RawPtr(from_ptr), _) if from_ptr.ty == to_ty => span_lint(
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2017-09-12 12:26:40 +00:00
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cx,
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CROSSPOINTER_TRANSMUTE,
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|
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e.span,
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&format!(
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"transmute from a type (`{}`) to the type that it points to (`{}`)",
|
2018-11-27 20:14:15 +00:00
|
|
|
from_ty, to_ty
|
2017-09-12 12:26:40 +00:00
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),
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2017-09-05 09:33:04 +00:00
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),
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2018-08-22 21:34:52 +00:00
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|
|
(_, &ty::RawPtr(to_ptr)) if to_ptr.ty == from_ty => span_lint(
|
2017-09-12 12:26:40 +00:00
|
|
|
cx,
|
|
|
|
CROSSPOINTER_TRANSMUTE,
|
|
|
|
e.span,
|
2017-11-04 19:55:56 +00:00
|
|
|
&format!(
|
|
|
|
"transmute from a type (`{}`) to a pointer to that type (`{}`)",
|
2018-11-27 20:14:15 +00:00
|
|
|
from_ty, to_ty
|
2017-11-04 19:55:56 +00:00
|
|
|
),
|
2017-09-12 12:26:40 +00:00
|
|
|
),
|
2018-08-22 21:34:52 +00:00
|
|
|
(&ty::RawPtr(from_pty), &ty::Ref(_, to_ref_ty, mutbl)) => span_lint_and_then(
|
2017-09-12 12:26:40 +00:00
|
|
|
cx,
|
|
|
|
TRANSMUTE_PTR_TO_REF,
|
|
|
|
e.span,
|
|
|
|
&format!(
|
|
|
|
"transmute from a pointer type (`{}`) to a reference type \
|
2017-11-04 19:55:56 +00:00
|
|
|
(`{}`)",
|
2018-11-27 20:14:15 +00:00
|
|
|
from_ty, to_ty
|
2017-09-12 12:26:40 +00:00
|
|
|
),
|
|
|
|
|db| {
|
|
|
|
let arg = sugg::Sugg::hir(cx, &args[0], "..");
|
2018-05-11 06:37:48 +00:00
|
|
|
let (deref, cast) = if mutbl == Mutability::MutMutable {
|
2017-09-12 12:26:40 +00:00
|
|
|
("&mut *", "*mut")
|
|
|
|
} else {
|
|
|
|
("&*", "*const")
|
|
|
|
};
|
2016-03-24 22:48:38 +00:00
|
|
|
|
2018-05-11 06:37:48 +00:00
|
|
|
let arg = if from_pty.ty == to_ref_ty {
|
2017-09-12 12:26:40 +00:00
|
|
|
arg
|
|
|
|
} else {
|
2018-05-11 06:37:48 +00:00
|
|
|
arg.as_ty(&format!("{} {}", cast, get_type_snippet(cx, qpath, to_ref_ty)))
|
2017-09-12 12:26:40 +00:00
|
|
|
};
|
2016-03-24 22:48:38 +00:00
|
|
|
|
2019-01-27 12:33:56 +00:00
|
|
|
db.span_suggestion(
|
2018-09-18 15:07:54 +00:00
|
|
|
e.span,
|
|
|
|
"try",
|
|
|
|
sugg::make_unop(deref, arg).to_string(),
|
|
|
|
Applicability::Unspecified,
|
|
|
|
);
|
2017-09-12 12:26:40 +00:00
|
|
|
},
|
|
|
|
),
|
2018-11-27 20:14:15 +00:00
|
|
|
(&ty::Int(ast::IntTy::I32), &ty::Char) | (&ty::Uint(ast::UintTy::U32), &ty::Char) => {
|
|
|
|
span_lint_and_then(
|
|
|
|
cx,
|
|
|
|
TRANSMUTE_INT_TO_CHAR,
|
|
|
|
e.span,
|
|
|
|
&format!("transmute from a `{}` to a `char`", from_ty),
|
|
|
|
|db| {
|
|
|
|
let arg = sugg::Sugg::hir(cx, &args[0], "..");
|
|
|
|
let arg = if let ty::Int(_) = from_ty.sty {
|
2019-03-15 22:44:42 +00:00
|
|
|
arg.as_ty(ast::UintTy::U32)
|
2018-11-27 20:14:15 +00:00
|
|
|
} else {
|
|
|
|
arg
|
|
|
|
};
|
2019-01-27 12:33:56 +00:00
|
|
|
db.span_suggestion(
|
2018-11-27 20:14:15 +00:00
|
|
|
e.span,
|
|
|
|
"consider using",
|
|
|
|
format!("std::char::from_u32({}).unwrap()", arg.to_string()),
|
|
|
|
Applicability::Unspecified,
|
|
|
|
);
|
|
|
|
},
|
|
|
|
)
|
|
|
|
},
|
2018-08-22 21:34:52 +00:00
|
|
|
(&ty::Ref(_, ty_from, from_mutbl), &ty::Ref(_, ty_to, to_mutbl)) => {
|
2017-10-29 01:27:45 +00:00
|
|
|
if_chain! {
|
2018-08-22 21:34:52 +00:00
|
|
|
if let (&ty::Slice(slice_ty), &ty::Str) = (&ty_from.sty, &ty_to.sty);
|
|
|
|
if let ty::Uint(ast::UintTy::U8) = slice_ty.sty;
|
2018-05-11 06:37:48 +00:00
|
|
|
if from_mutbl == to_mutbl;
|
2017-10-29 01:27:45 +00:00
|
|
|
then {
|
2018-05-11 06:37:48 +00:00
|
|
|
let postfix = if from_mutbl == Mutability::MutMutable {
|
2017-10-29 01:27:45 +00:00
|
|
|
"_mut"
|
|
|
|
} else {
|
|
|
|
""
|
|
|
|
};
|
|
|
|
|
|
|
|
span_lint_and_then(
|
|
|
|
cx,
|
|
|
|
TRANSMUTE_BYTES_TO_STR,
|
|
|
|
e.span,
|
|
|
|
&format!("transmute from a `{}` to a `{}`", from_ty, to_ty),
|
|
|
|
|db| {
|
2019-01-27 12:33:56 +00:00
|
|
|
db.span_suggestion(
|
2017-10-29 01:27:45 +00:00
|
|
|
e.span,
|
|
|
|
"consider using",
|
|
|
|
format!(
|
|
|
|
"std::str::from_utf8{}({}).unwrap()",
|
|
|
|
postfix,
|
|
|
|
snippet(cx, args[0].span, ".."),
|
|
|
|
),
|
2018-09-15 16:14:08 +00:00
|
|
|
Applicability::Unspecified,
|
2017-10-29 01:27:45 +00:00
|
|
|
);
|
|
|
|
}
|
|
|
|
)
|
2018-04-11 09:17:59 +00:00
|
|
|
} else {
|
2018-05-29 05:12:42 +00:00
|
|
|
if cx.tcx.erase_regions(&from_ty) != cx.tcx.erase_regions(&to_ty) {
|
2018-05-14 17:24:31 +00:00
|
|
|
span_lint_and_then(
|
|
|
|
cx,
|
|
|
|
TRANSMUTE_PTR_TO_PTR,
|
|
|
|
e.span,
|
|
|
|
"transmute from a reference to a reference",
|
|
|
|
|db| if let Some(arg) = sugg::Sugg::hir_opt(cx, &args[0]) {
|
2018-11-27 20:14:15 +00:00
|
|
|
let ty_from_and_mut = ty::TypeAndMut {
|
|
|
|
ty: ty_from,
|
|
|
|
mutbl: from_mutbl
|
|
|
|
};
|
2018-05-14 17:24:31 +00:00
|
|
|
let ty_to_and_mut = ty::TypeAndMut { ty: ty_to, mutbl: to_mutbl };
|
2018-11-27 20:14:15 +00:00
|
|
|
let sugg_paren = arg
|
|
|
|
.as_ty(cx.tcx.mk_ptr(ty_from_and_mut))
|
|
|
|
.as_ty(cx.tcx.mk_ptr(ty_to_and_mut));
|
2018-05-14 17:24:31 +00:00
|
|
|
let sugg = if to_mutbl == Mutability::MutMutable {
|
|
|
|
sugg_paren.mut_addr_deref()
|
|
|
|
} else {
|
|
|
|
sugg_paren.addr_deref()
|
|
|
|
};
|
2019-01-27 12:33:56 +00:00
|
|
|
db.span_suggestion(
|
2018-09-18 15:07:54 +00:00
|
|
|
e.span,
|
|
|
|
"try",
|
|
|
|
sugg.to_string(),
|
|
|
|
Applicability::Unspecified,
|
|
|
|
);
|
2018-05-14 17:24:31 +00:00
|
|
|
},
|
|
|
|
)
|
|
|
|
}
|
2017-10-29 01:27:45 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
},
|
2018-08-22 21:34:52 +00:00
|
|
|
(&ty::RawPtr(_), &ty::RawPtr(to_ty)) => span_lint_and_then(
|
2018-04-11 09:17:59 +00:00
|
|
|
cx,
|
|
|
|
TRANSMUTE_PTR_TO_PTR,
|
|
|
|
e.span,
|
|
|
|
"transmute from a pointer to a pointer",
|
2018-11-27 20:14:15 +00:00
|
|
|
|db| {
|
|
|
|
if let Some(arg) = sugg::Sugg::hir_opt(cx, &args[0]) {
|
|
|
|
let sugg = arg.as_ty(cx.tcx.mk_ptr(to_ty));
|
2019-01-27 12:34:23 +00:00
|
|
|
db.span_suggestion(e.span, "try", sugg.to_string(), Applicability::Unspecified);
|
2018-11-27 20:14:15 +00:00
|
|
|
}
|
2018-04-11 09:17:59 +00:00
|
|
|
},
|
|
|
|
),
|
2018-08-22 21:34:52 +00:00
|
|
|
(&ty::Int(ast::IntTy::I8), &ty::Bool) | (&ty::Uint(ast::UintTy::U8), &ty::Bool) => {
|
2017-11-04 19:55:56 +00:00
|
|
|
span_lint_and_then(
|
|
|
|
cx,
|
|
|
|
TRANSMUTE_INT_TO_BOOL,
|
|
|
|
e.span,
|
|
|
|
&format!("transmute from a `{}` to a `bool`", from_ty),
|
|
|
|
|db| {
|
|
|
|
let arg = sugg::Sugg::hir(cx, &args[0], "..");
|
|
|
|
let zero = sugg::Sugg::NonParen(Cow::from("0"));
|
2019-01-27 12:33:56 +00:00
|
|
|
db.span_suggestion(
|
2017-11-04 19:55:56 +00:00
|
|
|
e.span,
|
|
|
|
"consider using",
|
|
|
|
sugg::make_binop(ast::BinOpKind::Ne, &arg, &zero).to_string(),
|
2018-09-15 16:14:08 +00:00
|
|
|
Applicability::Unspecified,
|
2017-11-04 19:55:56 +00:00
|
|
|
);
|
|
|
|
},
|
|
|
|
)
|
|
|
|
},
|
2018-11-27 20:14:15 +00:00
|
|
|
(&ty::Int(_), &ty::Float(_)) | (&ty::Uint(_), &ty::Float(_)) => span_lint_and_then(
|
|
|
|
cx,
|
|
|
|
TRANSMUTE_INT_TO_FLOAT,
|
|
|
|
e.span,
|
|
|
|
&format!("transmute from a `{}` to a `{}`", from_ty, to_ty),
|
|
|
|
|db| {
|
|
|
|
let arg = sugg::Sugg::hir(cx, &args[0], "..");
|
|
|
|
let arg = if let ty::Int(int_ty) = from_ty.sty {
|
|
|
|
arg.as_ty(format!(
|
|
|
|
"u{}",
|
|
|
|
int_ty.bit_width().map_or_else(|| "size".to_string(), |v| v.to_string())
|
|
|
|
))
|
|
|
|
} else {
|
|
|
|
arg
|
|
|
|
};
|
2019-01-27 12:33:56 +00:00
|
|
|
db.span_suggestion(
|
2018-11-27 20:14:15 +00:00
|
|
|
e.span,
|
|
|
|
"consider using",
|
|
|
|
format!("{}::from_bits({})", to_ty, arg.to_string()),
|
|
|
|
Applicability::Unspecified,
|
|
|
|
);
|
|
|
|
},
|
|
|
|
),
|
2017-09-12 12:26:40 +00:00
|
|
|
_ => return,
|
|
|
|
};
|
|
|
|
}
|
2016-03-24 22:48:38 +00:00
|
|
|
}
|
2016-06-27 11:46:21 +00:00
|
|
|
}
|
2016-03-24 22:48:38 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
2016-09-19 15:59:12 +00:00
|
|
|
|
2019-01-31 01:15:29 +00:00
|
|
|
/// Gets the snippet of `Bar` in `…::transmute<Foo, &Bar>`. If that snippet is
|
2017-08-09 07:30:56 +00:00
|
|
|
/// not available , use
|
|
|
|
/// the type's `ToString` implementation. In weird cases it could lead to types
|
|
|
|
/// with invalid `'_`
|
2016-09-19 15:59:12 +00:00
|
|
|
/// lifetime, but it should be rare.
|
2018-07-23 11:01:12 +00:00
|
|
|
fn get_type_snippet(cx: &LateContext<'_, '_>, path: &QPath, to_ref_ty: Ty<'_>) -> String {
|
2016-12-02 16:38:31 +00:00
|
|
|
let seg = last_path_segment(path);
|
2017-10-23 19:18:02 +00:00
|
|
|
if_chain! {
|
2018-06-24 13:32:40 +00:00
|
|
|
if let Some(ref params) = seg.args;
|
2017-10-23 19:18:02 +00:00
|
|
|
if !params.parenthesized;
|
2018-06-24 21:42:52 +00:00
|
|
|
if let Some(to_ty) = params.args.iter().filter_map(|arg| match arg {
|
|
|
|
GenericArg::Type(ty) => Some(ty),
|
2019-02-19 07:34:43 +00:00
|
|
|
_ => None,
|
2018-06-24 21:42:52 +00:00
|
|
|
}).nth(1);
|
2018-07-12 08:03:06 +00:00
|
|
|
if let TyKind::Rptr(_, ref to_ty) = to_ty.node;
|
2017-10-23 19:18:02 +00:00
|
|
|
then {
|
2017-10-27 08:51:43 +00:00
|
|
|
return snippet(cx, to_ty.ty.span, &to_ref_ty.to_string()).to_string();
|
2017-10-23 19:18:02 +00:00
|
|
|
}
|
|
|
|
}
|
2016-09-19 15:59:12 +00:00
|
|
|
|
2017-10-27 08:51:43 +00:00
|
|
|
to_ref_ty.to_string()
|
2016-09-19 15:59:12 +00:00
|
|
|
}
|