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