Merge pull request #470 from sanxiyn/match-ref-pats

Extend match_ref_pats to desugared matches
This commit is contained in:
Manish Goregaokar 2015-11-25 10:37:09 +05:30
commit c61c776308
13 changed files with 74 additions and 39 deletions

View file

@ -44,7 +44,7 @@ impl LintPass for ApproxConstant {
impl LateLintPass for ApproxConstant {
fn check_expr(&mut self, cx: &LateContext, e: &Expr) {
if let &ExprLit(ref lit) = &e.node {
if let ExprLit(ref lit) = e.node {
check_lit(cx, lit, e);
}
}

View file

@ -42,7 +42,7 @@ impl LateLintPass for AttrPass {
}
fn is_relevant_item(item: &Item) -> bool {
if let &ItemFn(_, _, _, _, _, ref block) = &item.node {
if let ItemFn(_, _, _, _, _, ref block) = item.node {
is_relevant_block(block)
} else { false }
}

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@ -182,7 +182,7 @@ fn check_ineffective_gt(cx: &LateContext, span: Span, m: u64, c: u64, op: &str)
fn fetch_int_literal(cx: &LateContext, lit : &Expr) -> Option<u64> {
match lit.node {
ExprLit(ref lit_ptr) => {
if let &LitInt(value, _) = &lit_ptr.node {
if let LitInt(value, _) = lit_ptr.node {
Option::Some(value) //TODO: Handle sign
} else { Option::None }
}

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@ -125,7 +125,7 @@ fn check_len_zero(cx: &LateContext, span: Span, name: &Name,
fn has_is_empty(cx: &LateContext, expr: &Expr) -> bool {
/// get a ImplOrTraitItem and return true if it matches is_empty(self)
fn is_is_empty(cx: &LateContext, id: &ImplOrTraitItemId) -> bool {
if let &MethodTraitItemId(def_id) = id {
if let MethodTraitItemId(def_id) = *id {
if let ty::MethodTraitItem(ref method) =
cx.tcx.impl_or_trait_item(def_id) {
method.name.as_str() == "is_empty"

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@ -168,7 +168,7 @@ impl <'v, 't> RefVisitor<'v, 't> {
}
fn record(&mut self, lifetime: &Option<Lifetime>) {
if let &Some(ref lt) = lifetime {
if let Some(ref lt) = *lifetime {
if lt.name.as_str() == "'static" {
self.lts.push(Static);
} else {

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@ -2,6 +2,7 @@ use rustc::lint::*;
use rustc_front::hir::*;
use rustc::middle::ty;
use syntax::ast::Lit_::LitBool;
use syntax::codemap::Span;
use utils::{snippet, span_lint, span_help_and_lint, in_external_macro, expr_block};
@ -25,9 +26,8 @@ impl LintPass for MatchPass {
impl LateLintPass for MatchPass {
fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
if in_external_macro(cx, expr.span) { return; }
if let ExprMatch(ref ex, ref arms, MatchSource::Normal) = expr.node {
if in_external_macro(cx, expr.span) { return; }
// check preconditions for SINGLE_MATCH
// only two arms
if arms.len() == 2 &&
@ -53,19 +53,6 @@ impl LateLintPass for MatchPass {
expr_block(cx, &arms[0].body, None, "..")));
}
// check preconditions for MATCH_REF_PATS
if has_only_ref_pats(arms) {
if let ExprAddrOf(Mutability::MutImmutable, ref inner) = ex.node {
span_lint(cx, MATCH_REF_PATS, expr.span, &format!(
"you don't need to add `&` to both the expression to match \
and the patterns: use `match {} {{ ...`", snippet(cx, inner.span, "..")));
} else {
span_lint(cx, MATCH_REF_PATS, expr.span, &format!(
"instead of prefixing all patterns with `&`, you can dereference the \
expression to match: `match *{} {{ ...`", snippet(cx, ex.span, "..")));
}
}
// check preconditions for MATCH_BOOL
// type of expression == bool
if cx.tcx.expr_ty(ex).sty == ty::TyBool {
@ -123,6 +110,22 @@ impl LateLintPass for MatchPass {
}
}
}
if let ExprMatch(ref ex, ref arms, source) = expr.node {
// check preconditions for MATCH_REF_PATS
if has_only_ref_pats(arms) {
if let ExprAddrOf(Mutability::MutImmutable, ref inner) = ex.node {
let template = match_template(cx, expr.span, source, "", inner);
span_lint(cx, MATCH_REF_PATS, expr.span, &format!(
"you don't need to add `&` to both the expression \
and the patterns: use `{}`", template));
} else {
let template = match_template(cx, expr.span, source, "*", ex);
span_lint(cx, MATCH_REF_PATS, expr.span, &format!(
"instead of prefixing all patterns with `&`, you can dereference the \
expression: `{}`", template));
}
}
}
}
}
@ -143,3 +146,25 @@ fn has_only_ref_pats(arms: &[Arm]) -> bool {
// look for Some(v) where there's at least one true element
mapped.map_or(false, |v| v.iter().any(|el| *el))
}
fn match_template(cx: &LateContext,
span: Span,
source: MatchSource,
op: &str,
expr: &Expr) -> String {
let expr_snippet = snippet(cx, expr.span, "..");
match source {
MatchSource::Normal => {
format!("match {}{} {{ ...", op, expr_snippet)
}
MatchSource::IfLetDesugar { .. } => {
format!("if let ... = {}{} {{", op, expr_snippet)
}
MatchSource::WhileLetDesugar => {
format!("while let ... = {}{} {{", op, expr_snippet)
}
MatchSource::ForLoopDesugar => {
cx.sess().span_bug(span, "for loop desugared to match with &-patterns!")
}
}
}

View file

@ -84,10 +84,10 @@ impl LateLintPass for CmpNan {
fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
if let ExprBinary(ref cmp, ref left, ref right) = expr.node {
if is_comparison_binop(cmp.node) {
if let &ExprPath(_, ref path) = &left.node {
if let ExprPath(_, ref path) = left.node {
check_nan(cx, path, expr.span);
}
if let &ExprPath(_, ref path) = &right.node {
if let ExprPath(_, ref path) = right.node {
check_nan(cx, path, expr.span);
}
}
@ -189,7 +189,7 @@ fn check_to_owned(cx: &LateContext, expr: &Expr, other_span: Span, left: bool, o
}
}
ExprCall(ref path, ref v) if v.len() == 1 => {
if let &ExprPath(None, ref path) = &path.node {
if let ExprPath(None, ref path) = path.node {
if match_path(path, &["String", "from_str"]) ||
match_path(path, &["String", "from"]) {
snippet(cx, v[0].span, "..")
@ -235,7 +235,7 @@ impl LintPass for ModuloOne {
impl LateLintPass for ModuloOne {
fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
if let ExprBinary(ref cmp, _, ref right) = expr.node {
if let &Spanned {node: BinOp_::BiRem, ..} = cmp {
if let Spanned {node: BinOp_::BiRem, ..} = *cmp {
if is_integer_literal(right, 1) {
cx.span_lint(MODULO_ONE, expr.span, "any number modulo 1 will be 0");
}

View file

@ -34,7 +34,7 @@ pub struct MutexAtomic;
impl LateLintPass for MutexAtomic {
fn check_expr(&mut self, cx: &LateContext, expr: &Expr) {
let ty = cx.tcx.expr_ty(expr);
if let &ty::TyStruct(_, subst) = &ty.sty {
if let ty::TyStruct(_, subst) = ty.sty {
if match_type(cx, ty, &MUTEX_PATH) {
let mutex_param = &subst.types.get(ParamSpace::TypeSpace, 0).sty;
if let Some(atomic_name) = get_atomic_name(mutex_param) {

View file

@ -28,13 +28,13 @@ impl LintPass for PtrArg {
impl LateLintPass for PtrArg {
fn check_item(&mut self, cx: &LateContext, item: &Item) {
if let &ItemFn(ref decl, _, _, _, _, _) = &item.node {
if let ItemFn(ref decl, _, _, _, _, _) = item.node {
check_fn(cx, decl);
}
}
fn check_impl_item(&mut self, cx: &LateContext, item: &ImplItem) {
if let &ImplItemKind::Method(ref sig, _) = &item.node {
if let ImplItemKind::Method(ref sig, _) = item.node {
if let Some(Node::NodeItem(it)) = cx.tcx.map.find(cx.tcx.map.get_parent(item.id)) {
if let ItemImpl(_, _, _, Some(_), _, _) = it.node {
return; // ignore trait impls
@ -45,7 +45,7 @@ impl LateLintPass for PtrArg {
}
fn check_trait_item(&mut self, cx: &LateContext, item: &TraitItem) {
if let &MethodTraitItem(ref sig, _) = &item.node {
if let MethodTraitItem(ref sig, _) = item.node {
check_fn(cx, &sig.decl);
}
}

View file

@ -40,10 +40,10 @@ impl LateLintPass for StepByZero {
if_let_chain! {
[
// .iter() call
let &ExprMethodCall( Spanned { node: ref iter_name, .. }, _, ref iter_args ) = iter,
let ExprMethodCall( Spanned { node: ref iter_name, .. }, _, ref iter_args ) = *iter,
iter_name.as_str() == "iter",
// range expression in .zip() call: 0..x.len()
let &ExprRange(Some(ref from), Some(ref to)) = zip_arg,
let ExprRange(Some(ref from), Some(ref to)) = *zip_arg,
is_integer_literal(from, 0),
// .len() call
let ExprMethodCall(Spanned { node: ref len_name, .. }, _, ref len_args) = to.node,

View file

@ -63,8 +63,8 @@ fn check_decl(cx: &LateContext, decl: &Decl, bindings: &mut Vec<(Name, Span)>) {
if is_from_for_desugar(decl) { return; }
if let DeclLocal(ref local) = decl.node {
let Local{ ref pat, ref ty, ref init, id: _, span } = **local;
if let &Some(ref t) = ty { check_ty(cx, t, bindings) }
if let &Some(ref o) = init {
if let Some(ref t) = *ty { check_ty(cx, t, bindings) }
if let Some(ref o) = *init {
check_expr(cx, o, bindings);
check_pat(cx, pat, &Some(o), span, bindings);
} else {
@ -210,7 +210,7 @@ fn check_expr(cx: &LateContext, expr: &Expr, bindings: &mut Vec<(Name, Span)>) {
ExprIf(ref cond, ref then, ref otherwise) => {
check_expr(cx, cond, bindings);
check_block(cx, then, bindings);
if let &Some(ref o) = otherwise { check_expr(cx, o, bindings); }
if let Some(ref o) = *otherwise { check_expr(cx, o, bindings); }
}
ExprWhile(ref cond, ref block, _) => {
check_expr(cx, cond, bindings);

View file

@ -34,14 +34,14 @@ impl LintPass for StringAdd {
impl LateLintPass for StringAdd {
fn check_expr(&mut self, cx: &LateContext, e: &Expr) {
if let &ExprBinary(Spanned{ node: BiAdd, .. }, ref left, _) = &e.node {
if let ExprBinary(Spanned{ node: BiAdd, .. }, ref left, _) = e.node {
if is_string(cx, left) {
if let Allow = cx.current_level(STRING_ADD_ASSIGN) {
// the string_add_assign is allow, so no duplicates
} else {
let parent = get_parent_expr(cx, e);
if let Some(ref p) = parent {
if let &ExprAssign(ref target, _) = &p.node {
if let ExprAssign(ref target, _) = p.node {
// avoid duplicate matches
if is_exp_equal(cx, target, left) { return; }
}
@ -51,7 +51,7 @@ impl LateLintPass for StringAdd {
"you added something to a string. \
Consider using `String::push_str()` instead")
}
} else if let &ExprAssign(ref target, ref src) = &e.node {
} else if let ExprAssign(ref target, ref src) = e.node {
if is_string(cx, target) && is_add(cx, src, target) {
span_lint(cx, STRING_ADD_ASSIGN, e.span,
"you assigned the result of adding something to this string. \

View file

@ -78,7 +78,7 @@ fn match_bool() {
fn ref_pats() {
{
let v = &Some(0);
match v { //~ERROR instead of prefixing all patterns with `&`
match v { //~ERROR dereference the expression: `match *v { ...`
&Some(v) => println!("{:?}", v),
&None => println!("none"),
}
@ -88,13 +88,13 @@ fn ref_pats() {
}
}
let tup =& (1, 2);
match tup { //~ERROR instead of prefixing all patterns with `&`
match tup { //~ERROR dereference the expression: `match *tup { ...`
&(v, 1) => println!("{}", v),
_ => println!("none"),
}
// special case: using & both in expr and pats
let w = Some(0);
match &w { //~ERROR you don't need to add `&` to both
match &w { //~ERROR use `match w { ...`
&Some(v) => println!("{:?}", v),
&None => println!("none"),
}
@ -103,6 +103,16 @@ fn ref_pats() {
match w {
_ => println!("none"),
}
let a = &Some(0);
if let &None = a { //~ERROR dereference the expression: `if let ... = *a {`
println!("none");
}
let b = Some(0);
if let &None = &b { //~ERROR use `if let ... = b {`
println!("none");
}
}
fn main() {