use rustc::lint::*;
use std::collections::HashMap;
+use std::char;
use syntax::ast::*;
use syntax::codemap::Span;
use syntax::visit::FnKind;
-use utils::{span_lint, span_help_and_lint, snippet, span_lint_and_then};
-/// **What it does:** This lint checks for structure field patterns bound to wildcards.
+use crate::utils::{constants, in_external_macro, snippet, snippet_opt, span_help_and_lint, span_lint, span_lint_and_then};
+
+/// **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! {
+ 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! {
+ 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! {
+ 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?** Using `..` instead is shorter and leaves the focus on the fields that are actually bound.
+/// **Why is this bad?** It can mislead C/C++ programmers to think `x` was
+/// decremented.
///
/// **Known problems:** None.
///
-/// **Example:** `let { a: _, b: ref b, c: _ } = ..`
-declare_lint! {
- pub UNNEEDED_FIELD_PATTERN, Warn,
- "Struct fields are bound to a wildcard instead of using `..`"
+/// **Example:**
+/// ```rust
+/// --x;
+/// ```
+declare_clippy_lint! {
+ pub DOUBLE_NEG,
+ style,
+ "`--x`, which is a double negation of `x` and not a pre-decrement as in C/C++"
}
-/// **What it does:** This lint checks for function arguments having the similar names differing by an underscore
+/// **What it does:** Warns on hexadecimal literals with mixed-case letter
+/// digits.
///
-/// **Why is this bad?** It affects code readability
+/// **Why is this bad?** It looks confusing.
///
/// **Known problems:** None.
///
-/// **Example:** `fn foo(a: i32, _a: i32) {}`
-declare_lint! {
- pub DUPLICATE_UNDERSCORE_ARGUMENT, Warn,
- "Function arguments having names which only differ by an underscore"
+/// **Example:**
+/// ```rust
+/// let y = 0x1a9BAcD;
+/// ```
+declare_clippy_lint! {
+ pub MIXED_CASE_HEX_LITERALS,
+ style,
+ "hex literals whose letter digits are not consistently upper- or lowercased"
}
-/// **What it does:** This lint detects closures called in the same expression where they are defined.
+/// **What it does:** Warns if literal suffixes are not separated by an
+/// underscore.
///
-/// **Why is this bad?** It is unnecessarily adding to the expression's complexity.
+/// **Why is this bad?** It is much less readable.
///
/// **Known problems:** None.
///
-/// **Example:** `(|| 42)()`
-declare_lint! {
- pub REDUNDANT_CLOSURE_CALL, Warn,
- "Closures should not be called in the expression they are defined"
+/// **Example:**
+/// ```rust
+/// let y = 123832i32;
+/// ```
+declare_clippy_lint! {
+ pub UNSEPARATED_LITERAL_SUFFIX,
+ pedantic,
+ "literals whose suffix is not separated by an underscore"
}
-/// **What it does:** This lint detects expressions of the form `--x`
+/// **What it does:** Warns if an integral constant literal starts with `0`.
///
-/// **Why is this bad?** It can mislead C/C++ programmers to think `x` was decremented.
+/// **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:** `--x;`
-declare_lint! {
- pub DOUBLE_NEG, Warn,
- "`--x` is a double negation of `x` and not a pre-decrement as in C or C++"
+/// **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! {
+ 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! {
+ pub BUILTIN_TYPE_SHADOW,
+ style,
+ "shadowing a builtin type"
+}
#[derive(Copy, Clone)]
pub struct MiscEarly;
impl LintPass for MiscEarly {
fn get_lints(&self) -> LintArray {
- lint_array!(UNNEEDED_FIELD_PATTERN, DUPLICATE_UNDERSCORE_ARGUMENT, REDUNDANT_CLOSURE_CALL, DOUBLE_NEG)
+ lint_array!(
+ UNNEEDED_FIELD_PATTERN,
+ DUPLICATE_UNDERSCORE_ARGUMENT,
+ REDUNDANT_CLOSURE_CALL,
+ DOUBLE_NEG,
+ MIXED_CASE_HEX_LITERALS,
+ UNSEPARATED_LITERAL_SUFFIX,
+ ZERO_PREFIXED_LITERAL,
+ BUILTIN_TYPE_SHADOW
+ )
}
}
impl EarlyLintPass for MiscEarly {
+ fn check_generics(&mut self, cx: &EarlyContext, gen: &Generics) {
+ for param in &gen.params {
+ if let GenericParamKind::Type { .. } = param.kind {
+ let name = param.ident.name.as_str();
+ if constants::BUILTIN_TYPES.contains(&&*name) {
+ span_lint(
+ cx,
+ BUILTIN_TYPE_SHADOW,
+ param.ident.span,
+ &format!("This generic shadows the built-in type `{}`", name),
+ );
+ }
+ }
+ }
+ }
+
fn check_pat(&mut self, cx: &EarlyContext, pat: &Pat) {
if let PatKind::Struct(ref npat, ref pfields, _) = pat.node {
let mut wilds = 0;
- let type_name = npat.segments.last().expect("A path must have at least one segment").identifier.name;
+ let type_name = npat.segments
+ .last()
+ .expect("A path must have at least one segment")
+ .ident
+ .name;
for field in pfields {
if field.node.pat.node == PatKind::Wild {
}
}
if !pfields.is_empty() && wilds == pfields.len() {
- span_help_and_lint(cx,
- UNNEEDED_FIELD_PATTERN,
- pat.span,
- "All the struct fields are matched to a wildcard pattern, consider using `..`.",
- &format!("Try with `{} {{ .. }}` instead", type_name));
+ span_help_and_lint(
+ cx,
+ UNNEEDED_FIELD_PATTERN,
+ pat.span,
+ "All the struct fields are matched to a wildcard pattern, consider using `..`.",
+ &format!("Try with `{} {{ .. }}` instead", type_name),
+ );
return;
}
if wilds > 0 {
if field.node.pat.node == PatKind::Wild {
wilds -= 1;
if wilds > 0 {
- span_lint(cx,
- UNNEEDED_FIELD_PATTERN,
- field.span,
- "You matched a field with a wildcard pattern. Consider using `..` instead");
+ span_lint(
+ cx,
+ UNNEEDED_FIELD_PATTERN,
+ field.span,
+ "You matched a field with a wildcard pattern. Consider using `..` instead",
+ );
} else {
- span_help_and_lint(cx,
- UNNEEDED_FIELD_PATTERN,
- field.span,
- "You matched a field with a wildcard pattern. Consider using `..` \
- instead",
- &format!("Try with `{} {{ {}, .. }}`",
- type_name,
- normal[..].join(", ")));
+ span_help_and_lint(
+ cx,
+ UNNEEDED_FIELD_PATTERN,
+ field.span,
+ "You matched a field with a wildcard pattern. Consider using `..` \
+ instead",
+ &format!("Try with `{} {{ {}, .. }}`", type_name, normal[..].join(", ")),
+ );
}
}
}
}
}
- fn check_fn(&mut self, cx: &EarlyContext, _: FnKind, decl: &FnDecl, _: &Block, _: Span, _: NodeId) {
+ fn check_fn(&mut self, cx: &EarlyContext, _: FnKind, decl: &FnDecl, _: Span, _: NodeId) {
let mut registered_names: HashMap<String, Span> = HashMap::new();
- for ref arg in &decl.inputs {
- if let PatKind::Ident(_, sp_ident, None) = arg.pat.node {
- let arg_name = sp_ident.node.to_string();
+ for arg in &decl.inputs {
+ if let PatKind::Ident(_, ident, None) = arg.pat.node {
+ let arg_name = ident.name.to_string();
if arg_name.starts_with('_') {
if let Some(correspondence) = registered_names.get(&arg_name[1..]) {
- span_lint(cx,
- DUPLICATE_UNDERSCORE_ARGUMENT,
- *correspondence,
- &format!("`{}` already exists, having another argument having almost the same \
- name makes code comprehension and documentation more difficult",
- arg_name[1..].to_owned()));;
+ span_lint(
+ cx,
+ DUPLICATE_UNDERSCORE_ARGUMENT,
+ *correspondence,
+ &format!(
+ "`{}` already exists, having another argument having almost the same \
+ name makes code comprehension and documentation more difficult",
+ arg_name[1..].to_owned()
+ ),
+ );;
}
} else {
registered_names.insert(arg_name, arg.pat.span);
}
fn check_expr(&mut self, cx: &EarlyContext, expr: &Expr) {
+ if in_external_macro(cx, 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(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 = format!("{}", snippet(cx, block.span, ".."));
- db.span_suggestion(expr.span, "Try doing something like: ", hint);
- }
- });
- }
+ 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(
+ 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);
+ },
+ );
}
- }
- 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::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),
+ _ => (),
}
}
fn check_block(&mut self, cx: &EarlyContext, block: &Block) {
for w in block.stmts.windows(2) {
- if_let_chain! {[
- let StmtKind::Decl(ref first, _) = w[0].node,
- let DeclKind::Local(ref local) = first.node,
- let Option::Some(ref t) = local.init,
- let ExprKind::Closure(_,_,_,_) = t.node,
- let PatKind::Ident(_,sp_ident,_) = local.pat.node,
- let StmtKind::Semi(ref second,_) = w[1].node,
- let ExprKind::Assign(_,ref call) = second.node,
- let ExprKind::Call(ref closure,_) = call.node,
- let ExprKind::Path(_,ref path) = closure.node
- ], {
- if sp_ident.node == (&path.segments[0]).identifier {
- span_lint(cx, REDUNDANT_CLOSURE_CALL, second.span, "Closure called just once immediately after it was declared");
+ if_chain! {
+ if let StmtKind::Local(ref local) = w[0].node;
+ if let Option::Some(ref t) = local.init;
+ if let ExprKind::Closure(..) = t.node;
+ if let PatKind::Ident(_, ident, _) = local.pat.node;
+ if let StmtKind::Semi(ref second) = w[1].node;
+ if let ExprKind::Assign(_, ref call) = second.node;
+ if let ExprKind::Call(ref closure, _) = call.node;
+ if let ExprKind::Path(_, ref path) = closure.node;
+ then {
+ if ident == path.segments[0].ident {
+ span_lint(
+ cx,
+ REDUNDANT_CLOSURE_CALL,
+ second.span,
+ "Closure called just once immediately after it was declared",
+ );
+ }
}
- }}
+ }
+ }
+ }
+}
+
+impl MiscEarly {
+ fn check_lit(self, cx: &EarlyContext, lit: &Lit) {
+ if_chain! {
+ if let LitKind::Int(value, ..) = lit.node;
+ if let Some(src) = snippet_opt(cx, lit.span);
+ if let Some(firstch) = src.chars().next();
+ if char::to_digit(firstch, 10).is_some();
+ then {
+ let mut prev = '\0';
+ for ch in src.chars() {
+ if ch == 'i' || ch == 'u' {
+ if prev != '_' {
+ span_lint(cx, UNSEPARATED_LITERAL_SUFFIX, lit.span,
+ "integer type suffix should be separated by an underscore");
+ }
+ break;
+ }
+ prev = ch;
+ }
+ if src.starts_with("0x") {
+ let mut seen = (false, false);
+ for ch in src.chars() {
+ match ch {
+ 'a' ..= 'f' => seen.0 = true,
+ 'A' ..= 'F' => seen.1 = true,
+ 'i' | 'u' => break, // start of suffix already
+ _ => ()
+ }
+ }
+ if seen.0 && seen.1 {
+ span_lint(cx, MIXED_CASE_HEX_LITERALS, lit.span,
+ "inconsistent casing in hexadecimal literal");
+ }
+ } else if src.starts_with("0b") || src.starts_with("0o") {
+ /* nothing to do */
+ } else if value != 0 && src.starts_with('0') {
+ span_lint_and_then(cx,
+ ZERO_PREFIXED_LITERAL,
+ lit.span,
+ "this is a decimal constant",
+ |db| {
+ 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(),
+ );
+ 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')),
+ );
+ });
+ }
+ }
+ }
+ if_chain! {
+ if let LitKind::Float(..) = lit.node;
+ if let Some(src) = snippet_opt(cx, lit.span);
+ if let Some(firstch) = src.chars().next();
+ if char::to_digit(firstch, 10).is_some();
+ then {
+ let mut prev = '\0';
+ for ch in src.chars() {
+ if ch == 'f' {
+ if prev != '_' {
+ span_lint(cx, UNSEPARATED_LITERAL_SUFFIX, lit.span,
+ "float type suffix should be separated by an underscore");
+ }
+ break;
+ }
+ prev = ch;
+ }
+ }
}
}
}
projects / rust.git / blobdiff