-use rustc::lint::*;
+use crate::utils::{snippet, span_lint_and_then};
+use if_chain::if_chain;
use rustc::hir;
-use rustc::hir::BindingAnnotation;
use rustc::hir::def::Def;
-use syntax::ast;
-use crate::utils::{snippet, span_lint_and_then};
+use rustc::hir::BindingAnnotation;
+use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use rustc::{declare_lint_pass, declare_tool_lint};
+use rustc_errors::Applicability;
-/// **What it does:** Checks for variable declarations immediately followed by a
-/// conditional affectation.
-///
-/// **Why is this bad?** This is not idiomatic Rust.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust,ignore
-/// let foo;
-///
-/// if bar() {
-/// foo = 42;
-/// } else {
-/// foo = 0;
-/// }
-///
-/// let mut baz = None;
-///
-/// if bar() {
-/// baz = Some(42);
-/// }
-/// ```
-///
-/// should be written
-///
-/// ```rust,ignore
-/// let foo = if bar() {
-/// 42
-/// } else {
-/// 0
-/// };
-///
-/// let baz = if bar() {
-/// Some(42)
-/// } else {
-/// None
-/// };
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for variable declarations immediately followed by a
+ /// conditional affectation.
+ ///
+ /// **Why is this bad?** This is not idiomatic Rust.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// let foo;
+ ///
+ /// if bar() {
+ /// foo = 42;
+ /// } else {
+ /// foo = 0;
+ /// }
+ ///
+ /// let mut baz = None;
+ ///
+ /// if bar() {
+ /// baz = Some(42);
+ /// }
+ /// ```
+ ///
+ /// should be written
+ ///
+ /// ```rust,ignore
+ /// let foo = if bar() {
+ /// 42
+ /// } else {
+ /// 0
+ /// };
+ ///
+ /// let baz = if bar() {
+ /// Some(42)
+ /// } else {
+ /// None
+ /// };
+ /// ```
pub USELESS_LET_IF_SEQ,
style,
"unidiomatic `let mut` declaration followed by initialization in `if`"
}
-#[derive(Copy, Clone)]
-pub struct LetIfSeq;
-
-impl LintPass for LetIfSeq {
- fn get_lints(&self) -> LintArray {
- lint_array!(USELESS_LET_IF_SEQ)
- }
-}
+declare_lint_pass!(LetIfSeq => [USELESS_LET_IF_SEQ]);
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetIfSeq {
fn check_block(&mut self, cx: &LateContext<'a, 'tcx>, block: &'tcx hir::Block) {
while let Some(stmt) = it.next() {
if_chain! {
if let Some(expr) = it.peek();
- if let hir::StmtDecl(ref decl, _) = stmt.node;
- if let hir::DeclLocal(ref decl) = decl.node;
- if let hir::PatKind::Binding(mode, canonical_id, ref name, None) = decl.pat.node;
- if let hir::StmtExpr(ref if_, _) = expr.node;
- if let hir::ExprIf(ref cond, ref then, ref else_) = if_.node;
+ if let hir::StmtKind::Local(ref local) = stmt.node;
+ if let hir::PatKind::Binding(mode, canonical_id, ident, None) = local.pat.node;
+ if let hir::StmtKind::Expr(ref if_) = expr.node;
+ if let hir::ExprKind::If(ref cond, ref then, ref else_) = if_.node;
if !used_in_expr(cx, canonical_id, cond);
- if let hir::ExprBlock(ref then, _) = then.node;
+ if let hir::ExprKind::Block(ref then, _) = then.node;
if let Some(value) = check_assign(cx, canonical_id, &*then);
if !used_in_expr(cx, canonical_id, value);
then {
let span = stmt.span.to(if_.span);
let (default_multi_stmts, default) = if let Some(ref else_) = *else_ {
- if let hir::ExprBlock(ref else_, _) = else_.node {
+ if let hir::ExprKind::Block(ref else_, _) = else_.node {
if let Some(default) = check_assign(cx, canonical_id, else_) {
(else_.stmts.len() > 1, default)
- } else if let Some(ref default) = decl.init {
+ } else if let Some(ref default) = local.init {
(true, &**default)
} else {
continue;
} else {
continue;
}
- } else if let Some(ref default) = decl.init {
+ } else if let Some(ref default) = local.init {
(false, &**default)
} else {
continue;
let sug = format!(
"let {mut}{name} = if {cond} {{{then} {value} }} else {{{else} {default} }};",
mut=mutability,
- name=name.node,
+ name=ident.name,
cond=snippet(cx, cond.span, "_"),
then=if then.stmts.len() > 1 { " ..;" } else { "" },
else=if default_multi_stmts { " ..;" } else { "" },
span,
"`if _ { .. } else { .. }` is an expression",
|db| {
- db.span_suggestion(span,
- "it is more idiomatic to write",
- sug);
+ db.span_suggestion(
+ span,
+ "it is more idiomatic to write",
+ sug,
+ Applicability::HasPlaceholders,
+ );
if !mutability.is_empty() {
db.note("you might not need `mut` at all");
}
struct UsedVisitor<'a, 'tcx: 'a> {
cx: &'a LateContext<'a, 'tcx>,
- id: ast::NodeId,
+ id: hir::HirId,
used: bool,
}
impl<'a, 'tcx> hir::intravisit::Visitor<'tcx> for UsedVisitor<'a, 'tcx> {
fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
if_chain! {
- if let hir::ExprPath(ref qpath) = expr.node;
+ if let hir::ExprKind::Path(ref qpath) = expr.node;
if let Def::Local(local_id) = self.cx.tables.qpath_def(qpath, expr.hir_id);
if self.id == local_id;
then {
fn check_assign<'a, 'tcx>(
cx: &LateContext<'a, 'tcx>,
- decl: ast::NodeId,
+ decl: hir::HirId,
block: &'tcx hir::Block,
) -> Option<&'tcx hir::Expr> {
if_chain! {
if block.expr.is_none();
if let Some(expr) = block.stmts.iter().last();
- if let hir::StmtSemi(ref expr, _) = expr.node;
- if let hir::ExprAssign(ref var, ref value) = expr.node;
- if let hir::ExprPath(ref qpath) = var.node;
+ if let hir::StmtKind::Semi(ref expr) = expr.node;
+ if let hir::ExprKind::Assign(ref var, ref value) = expr.node;
+ if let hir::ExprKind::Path(ref qpath) = var.node;
if let Def::Local(local_id) = cx.tables.qpath_def(qpath, var.hir_id);
if decl == local_id;
then {
None
}
-fn used_in_expr<'a, 'tcx: 'a>(cx: &LateContext<'a, 'tcx>, id: ast::NodeId, expr: &'tcx hir::Expr) -> bool {
- let mut v = UsedVisitor {
- cx,
- id,
- used: false,
- };
+fn used_in_expr<'a, 'tcx: 'a>(cx: &LateContext<'a, 'tcx>, id: hir::HirId, expr: &'tcx hir::Expr) -> bool {
+ let mut v = UsedVisitor { cx, id, used: false };
hir::intravisit::walk_expr(&mut v, expr);
v.used
}
projects / rust.git / blobdiff