-use rustc::lint::*;
-use rustc::{declare_lint, lint_array};
+use crate::utils::{constants, snippet, snippet_opt, span_help_and_lint, span_lint, span_lint_and_then};
use if_chain::if_chain;
-use std::collections::HashMap;
+use rustc::lint::{in_external_macro, EarlyContext, EarlyLintPass, LintArray, LintContext, LintPass};
+use rustc::{declare_tool_lint, lint_array};
+use rustc_data_structures::fx::FxHashMap;
+use rustc_errors::Applicability;
use std::char;
use syntax::ast::*;
-use syntax::codemap::Span;
-use syntax::visit::FnKind;
-use crate::utils::{constants, in_external_macro, snippet, snippet_opt, span_help_and_lint, span_lint, span_lint_and_then};
+use syntax::source_map::Span;
+use syntax::visit::{walk_expr, FnKind, Visitor};
-/// **What it does:** Checks for structure field patterns bound to wildcards.
-///
-/// **Why is this bad?** Using `..` instead is shorter and leaves the focus on
-/// the fields that are actually bound.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// let { a: _, b: ref b, c: _ } = ..
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for structure field patterns bound to wildcards.
+ ///
+ /// **Why is this bad?** Using `..` instead is shorter and leaves the focus on
+ /// the fields that are actually bound.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// let { a: _, b: ref b, c: _ } = ..
+ /// ```
pub UNNEEDED_FIELD_PATTERN,
style,
"struct fields bound to a wildcard instead of using `..`"
}
-/// **What it does:** Checks for function arguments having the similar names
-/// differing by an underscore.
-///
-/// **Why is this bad?** It affects code readability.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// fn foo(a: i32, _a: i32) {}
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for function arguments having the similar names
+ /// differing by an underscore.
+ ///
+ /// **Why is this bad?** It affects code readability.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// fn foo(a: i32, _a: i32) {}
+ /// ```
pub DUPLICATE_UNDERSCORE_ARGUMENT,
style,
"function arguments having names which only differ by an underscore"
}
-/// **What it does:** Detects closures called in the same expression where they
-/// are defined.
-///
-/// **Why is this bad?** It is unnecessarily adding to the expression's
-/// complexity.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// (|| 42)()
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Detects closures called in the same expression where they
+ /// are defined.
+ ///
+ /// **Why is this bad?** It is unnecessarily adding to the expression's
+ /// complexity.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// (|| 42)()
+ /// ```
pub REDUNDANT_CLOSURE_CALL,
complexity,
"throwaway closures called in the expression they are defined"
}
-/// **What it does:** Detects expressions of the form `--x`.
-///
-/// **Why is this bad?** It can mislead C/C++ programmers to think `x` was
-/// decremented.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// --x;
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Detects expressions of the form `--x`.
+ ///
+ /// **Why is this bad?** It can mislead C/C++ programmers to think `x` was
+ /// decremented.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let mut x = 3;
+ /// --x;
+ /// ```
pub DOUBLE_NEG,
style,
"`--x`, which is a double negation of `x` and not a pre-decrement as in C/C++"
}
-/// **What it does:** Warns on hexadecimal literals with mixed-case letter
-/// digits.
-///
-/// **Why is this bad?** It looks confusing.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// let y = 0x1a9BAcD;
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Warns on hexadecimal literals with mixed-case letter
+ /// digits.
+ ///
+ /// **Why is this bad?** It looks confusing.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let y = 0x1a9BAcD;
+ /// ```
pub MIXED_CASE_HEX_LITERALS,
style,
"hex literals whose letter digits are not consistently upper- or lowercased"
}
-/// **What it does:** Warns if literal suffixes are not separated by an
-/// underscore.
-///
-/// **Why is this bad?** It is much less readable.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// let y = 123832i32;
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Warns if literal suffixes are not separated by an
+ /// underscore.
+ ///
+ /// **Why is this bad?** It is much less readable.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// let y = 123832i32;
+ /// ```
pub UNSEPARATED_LITERAL_SUFFIX,
pedantic,
"literals whose suffix is not separated by an underscore"
}
-/// **What it does:** Warns if an integral constant literal starts with `0`.
-///
-/// **Why is this bad?** In some languages (including the infamous C language
-/// and most of its
-/// family), this marks an octal constant. In Rust however, this is a decimal
-/// constant. This could
-/// be confusing for both the writer and a reader of the constant.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-///
-/// In Rust:
-/// ```rust
-/// fn main() {
-/// let a = 0123;
-/// println!("{}", a);
-/// }
-/// ```
-///
-/// prints `123`, while in C:
-///
-/// ```c
-/// #include <stdio.h>
-///
-/// int main() {
-/// int a = 0123;
-/// printf("%d\n", a);
-/// }
-/// ```
-///
-/// prints `83` (as `83 == 0o123` while `123 == 0o173`).
declare_clippy_lint! {
+ /// **What it does:** Warns if an integral constant literal starts with `0`.
+ ///
+ /// **Why is this bad?** In some languages (including the infamous C language
+ /// and most of its
+ /// family), this marks an octal constant. In Rust however, this is a decimal
+ /// constant. This could
+ /// be confusing for both the writer and a reader of the constant.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// In Rust:
+ /// ```rust
+ /// fn main() {
+ /// let a = 0123;
+ /// println!("{}", a);
+ /// }
+ /// ```
+ ///
+ /// prints `123`, while in C:
+ ///
+ /// ```c
+ /// #include <stdio.h>
+ ///
+ /// int main() {
+ /// int a = 0123;
+ /// printf("%d\n", a);
+ /// }
+ /// ```
+ ///
+ /// prints `83` (as `83 == 0o123` while `123 == 0o173`).
pub ZERO_PREFIXED_LITERAL,
complexity,
"integer literals starting with `0`"
}
-/// **What it does:** Warns if a generic shadows a built-in type.
-///
-/// **Why is this bad?** This gives surprising type errors.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-///
-/// ```rust
-/// impl<u32> Foo<u32> {
-/// fn impl_func(&self) -> u32 {
-/// 42
-/// }
-/// }
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Warns if a generic shadows a built-in type.
+ ///
+ /// **Why is this bad?** This gives surprising type errors.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ ///
+ /// ```ignore
+ /// impl<u32> Foo<u32> {
+ /// fn impl_func(&self) -> u32 {
+ /// 42
+ /// }
+ /// }
+ /// ```
pub BUILTIN_TYPE_SHADOW,
style,
"shadowing a builtin type"
BUILTIN_TYPE_SHADOW
)
}
+
+ fn name(&self) -> &'static str {
+ "MiscEarlyLints"
+ }
+}
+
+// Used to find `return` statements or equivalents e.g., `?`
+struct ReturnVisitor {
+ found_return: bool,
+}
+
+impl ReturnVisitor {
+ fn new() -> Self {
+ Self { found_return: false }
+ }
+}
+
+impl<'ast> Visitor<'ast> for ReturnVisitor {
+ fn visit_expr(&mut self, ex: &'ast Expr) {
+ if let ExprKind::Ret(_) = ex.node {
+ self.found_return = true;
+ } else if let ExprKind::Try(_) = ex.node {
+ self.found_return = true;
+ }
+
+ walk_expr(self, ex)
+ }
}
impl EarlyLintPass for MiscEarly {
}
}
- fn check_pat(&mut self, cx: &EarlyContext<'_>, pat: &Pat) {
+ fn check_pat(&mut self, cx: &EarlyContext<'_>, pat: &Pat, _: &mut bool) {
if let PatKind::Struct(ref npat, ref pfields, _) = pat.node {
let mut wilds = 0;
- let type_name = npat.segments
+ let type_name = npat
+ .segments
.last()
.expect("A path must have at least one segment")
.ident
for field in pfields {
match field.node.pat.node {
PatKind::Wild => {},
- _ => if let Ok(n) = cx.sess().codemap().span_to_snippet(field.span) {
- normal.push(n);
+ _ => {
+ if let Ok(n) = cx.sess().source_map().span_to_snippet(field.span) {
+ normal.push(n);
+ }
},
}
}
}
fn check_fn(&mut self, cx: &EarlyContext<'_>, _: FnKind<'_>, decl: &FnDecl, _: Span, _: NodeId) {
- let mut registered_names: HashMap<String, Span> = HashMap::new();
+ let mut registered_names: FxHashMap<String, Span> = FxHashMap::default();
for arg in &decl.inputs {
if let PatKind::Ident(_, ident, None) = arg.pat.node {
}
fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) {
- if in_external_macro(cx, expr.span) {
+ if in_external_macro(cx.sess(), expr.span) {
return;
}
match expr.node {
- ExprKind::Call(ref paren, _) => if let ExprKind::Paren(ref closure) = paren.node {
- if let ExprKind::Closure(_, _, _, ref decl, ref block, _) = closure.node {
- span_lint_and_then(
+ ExprKind::Call(ref paren, _) => {
+ if let ExprKind::Paren(ref closure) = paren.node {
+ if let ExprKind::Closure(_, _, _, ref decl, ref block, _) = closure.node {
+ let mut visitor = ReturnVisitor::new();
+ visitor.visit_expr(block);
+ if !visitor.found_return {
+ span_lint_and_then(
+ cx,
+ REDUNDANT_CLOSURE_CALL,
+ expr.span,
+ "Try not to call a closure in the expression where it is declared.",
+ |db| {
+ if decl.inputs.is_empty() {
+ let hint = snippet(cx, block.span, "..").into_owned();
+ db.span_suggestion(
+ expr.span,
+ "Try doing something like: ",
+ hint,
+ Applicability::MachineApplicable, // snippet
+ );
+ }
+ },
+ );
+ }
+ }
+ }
+ },
+ ExprKind::Unary(UnOp::Neg, ref inner) => {
+ if let ExprKind::Unary(UnOp::Neg, _) = inner.node {
+ span_lint(
cx,
- REDUNDANT_CLOSURE_CALL,
+ DOUBLE_NEG,
expr.span,
- "Try not to call a closure in the expression where it is declared.",
- |db| if decl.inputs.is_empty() {
- let hint = snippet(cx, block.span, "..").into_owned();
- db.span_suggestion(expr.span, "Try doing something like: ", hint);
- },
+ "`--x` could be misinterpreted as pre-decrement by C programmers, is usually a no-op",
);
}
},
- ExprKind::Unary(UnOp::Neg, ref inner) => if let ExprKind::Unary(UnOp::Neg, _) = inner.node {
- span_lint(
- cx,
- DOUBLE_NEG,
- expr.span,
- "`--x` could be misinterpreted as pre-decrement by C programmers, is usually a no-op",
- );
- },
ExprKind::Lit(ref lit) => self.check_lit(cx, lit),
_ => (),
}
db.span_suggestion(
lit.span,
"if you mean to use a decimal constant, remove the `0` to remove confusion",
- src.trim_left_matches(|c| c == '_' || c == '0').to_string(),
+ src.trim_start_matches(|c| c == '_' || c == '0').to_string(),
+ Applicability::MaybeIncorrect,
);
db.span_suggestion(
lit.span,
"if you mean to use an octal constant, use `0o`",
- format!("0o{}", src.trim_left_matches(|c| c == '_' || c == '0')),
+ format!("0o{}", src.trim_start_matches(|c| c == '_' || c == '0')),
+ Applicability::MaybeIncorrect,
);
});
}