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Remove all ExprRange

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Rustup to rustc 1.9.0-nightly (998a6720b 2016-03-07)
This commit is contained in:
mcarton 2016-03-07 16:31:38 +01:00
parent eb0a493442
commit 13bb22a68b
7 changed files with 125 additions and 45 deletions
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41
src/loops.rs
View File

@ -12,8 +12,10 @@ use std::borrow::Cow;
use std::collections::HashMap;
use utils::{snippet, span_lint, get_parent_expr, match_trait_method, match_type, in_external_macro,
span_help_and_lint, is_integer_literal, get_enclosing_block, span_lint_and_then, walk_ptrs_ty};
span_help_and_lint, is_integer_literal, get_enclosing_block, span_lint_and_then,
unsugar_range, walk_ptrs_ty};
use utils::{BTREEMAP_PATH, HASHMAP_PATH, LL_PATH, OPTION_PATH, RESULT_PATH, VEC_PATH};
use utils::UnsugaredRange;
/// **What it does:** This lint checks for looping over the range of `0..len` of some collection just to get the values by index.
///
@ -323,10 +325,9 @@ fn check_for_loop(cx: &LateContext, pat: &Pat, arg: &Expr, body: &Expr, expr: &E
/// Check for looping over a range and then indexing a sequence with it.
/// The iteratee must be a range literal.
fn check_for_loop_range(cx: &LateContext, pat: &Pat, arg: &Expr, body: &Expr, expr: &Expr) {
if let ExprRange(Some(ref l), ref r) = arg.node {
if let Some(UnsugaredRange { start: Some(ref start), ref end, .. }) = unsugar_range(&arg) {
// the var must be a single name
if let PatKind::Ident(_, ref ident, _) = pat.node {
let mut visitor = VarVisitor {
cx: cx,
var: ident.node.name,
@ -348,19 +349,19 @@ fn check_for_loop_range(cx: &LateContext, pat: &Pat, arg: &Expr, body: &Expr, ex
return;
}
let starts_at_zero = is_integer_literal(l, 0);
let starts_at_zero = is_integer_literal(start, 0);
let skip: Cow<_> = if starts_at_zero {
"".into()
} else {
format!(".skip({})", snippet(cx, l.span, "..")).into()
format!(".skip({})", snippet(cx, start.span, "..")).into()
};
let take: Cow<_> = if let Some(ref r) = *r {
if is_len_call(&r, &indexed) {
let take: Cow<_> = if let Some(ref end) = *end {
if is_len_call(&end, &indexed) {
"".into()
} else {
format!(".take({})", snippet(cx, r.span, "..")).into()
format!(".take({})", snippet(cx, end.span, "..")).into()
}
} else {
"".into()
@ -416,27 +417,27 @@ fn is_len_call(expr: &Expr, var: &Name) -> bool {
fn check_for_loop_reverse_range(cx: &LateContext, arg: &Expr, expr: &Expr) {
// if this for loop is iterating over a two-sided range...
if let ExprRange(Some(ref start_expr), Some(ref stop_expr)) = arg.node {
if let Some(UnsugaredRange { start: Some(ref start), end: Some(ref end), .. }) = unsugar_range(&arg) {
// ...and both sides are compile-time constant integers...
if let Ok(start_idx) = eval_const_expr_partial(&cx.tcx, start_expr, ExprTypeChecked, None) {
if let Ok(stop_idx) = eval_const_expr_partial(&cx.tcx, stop_expr, ExprTypeChecked, None) {
// ...and the start index is greater than the stop index,
if let Ok(start_idx) = eval_const_expr_partial(&cx.tcx, start, ExprTypeChecked, None) {
if let Ok(end_idx) = eval_const_expr_partial(&cx.tcx, end, ExprTypeChecked, None) {
// ...and the start index is greater than the end index,
// this loop will never run. This is often confusing for developers
// who think that this will iterate from the larger value to the
// smaller value.
let (sup, eq) = match (start_idx, stop_idx) {
(ConstVal::Int(start_idx), ConstVal::Int(stop_idx)) => {
(start_idx > stop_idx, start_idx == stop_idx)
let (sup, eq) = match (start_idx, end_idx) {
(ConstVal::Int(start_idx), ConstVal::Int(end_idx)) => {
(start_idx > end_idx, start_idx == end_idx)
}
(ConstVal::Uint(start_idx), ConstVal::Uint(stop_idx)) => {
(start_idx > stop_idx, start_idx == stop_idx)
(ConstVal::Uint(start_idx), ConstVal::Uint(end_idx)) => {
(start_idx > end_idx, start_idx == end_idx)
}
_ => (false, false),
};
if sup {
let start_snippet = snippet(cx, start_expr.span, "_");
let stop_snippet = snippet(cx, stop_expr.span, "_");
let start_snippet = snippet(cx, start.span, "_");
let end_snippet = snippet(cx, end.span, "_");
span_lint_and_then(cx,
REVERSE_RANGE_LOOP,
@ -447,7 +448,7 @@ fn check_for_loop_reverse_range(cx: &LateContext, arg: &Expr, expr: &Expr) {
"consider using the following if \
you are attempting to iterate \
over this range in reverse",
format!("({}..{}).rev()` ", stop_snippet, start_snippet));
format!("({}..{}).rev()` ", end_snippet, start_snippet));
});
} else if eq {
// if they are equal, it's also problematic - this loop

11
src/no_effect.rs
View File

@ -23,15 +23,11 @@ fn has_no_effect(cx: &LateContext, expr: &Expr) -> bool {
match expr.node {
Expr_::ExprLit(..) |
Expr_::ExprClosure(..) |
Expr_::ExprRange(None, None) |
Expr_::ExprPath(..) => true,
Expr_::ExprIndex(ref a, ref b) |
Expr_::ExprRange(Some(ref a), Some(ref b)) |
Expr_::ExprBinary(_, ref a, ref b) => has_no_effect(cx, a) && has_no_effect(cx, b),
Expr_::ExprVec(ref v) |
Expr_::ExprTup(ref v) => v.iter().all(|val| has_no_effect(cx, val)),
Expr_::ExprRange(Some(ref inner), None) |
Expr_::ExprRange(None, Some(ref inner)) |
Expr_::ExprRepeat(ref inner, _) |
Expr_::ExprCast(ref inner, _) |
Expr_::ExprType(ref inner, _) |
@ -55,6 +51,13 @@ fn has_no_effect(cx: &LateContext, expr: &Expr) -> bool {
_ => false,
}
}
Expr_::ExprBlock(ref block) => {
block.stmts.is_empty() && if let Some(ref expr) = block.expr {
has_no_effect(cx, expr)
} else {
false
}
}
_ => false,
}
}

10
src/ranges.rs
View File

@ -1,7 +1,7 @@
use rustc::lint::*;
use rustc_front::hir::*;
use syntax::codemap::Spanned;
use utils::{is_integer_literal, match_type, snippet};
use utils::{is_integer_literal, match_type, snippet, unsugar_range, UnsugaredRange};
/// **What it does:** This lint checks for iterating over ranges with a `.step_by(0)`, which never terminates.
///
@ -47,17 +47,17 @@ impl LateLintPass for StepByZero {
instead")
} else if name.as_str() == "zip" && args.len() == 2 {
let iter = &args[0].node;
let zip_arg = &args[1].node;
let zip_arg = &args[1];
if_let_chain! {
[
// .iter() call
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,
is_integer_literal(from, 0),
let Some(UnsugaredRange { start: Some(ref start), end: Some(ref end), .. }) = unsugar_range(zip_arg),
is_integer_literal(start, 0),
// .len() call
let ExprMethodCall(Spanned { node: ref len_name, .. }, _, ref len_args) = to.node,
let ExprMethodCall(Spanned { node: ref len_name, .. }, _, ref len_args) = end.node,
len_name.as_str() == "len" && len_args.len() == 1,
// .iter() and .len() called on same Path
let ExprPath(_, Path { segments: ref iter_path, .. }) = iter_args[0].node,

13
src/utils/hir.rs
View File

@ -109,9 +109,6 @@ impl<'a, 'tcx: 'a> SpanlessEq<'a, 'tcx> {
!self.ignore_fn && lname.node == rname.node && ltys.is_empty() && rtys.is_empty() &&
self.eq_exprs(largs, rargs)
}
(&ExprRange(ref lb, ref le), &ExprRange(ref rb, ref re)) => {
both(lb, rb, |l, r| self.eq_expr(l, r)) && both(le, re, |l, r| self.eq_expr(l, r))
}
(&ExprRepeat(ref le, ref ll), &ExprRepeat(ref re, ref rl)) => self.eq_expr(le, re) && self.eq_expr(ll, rl),
(&ExprRet(ref l), &ExprRet(ref r)) => both(l, r, |l, r| self.eq_expr(l, r)),
(&ExprPath(ref lqself, ref lsubpath), &ExprPath(ref rqself, ref rsubpath)) => {
@ -384,16 +381,6 @@ impl<'a, 'tcx: 'a> SpanlessHash<'a, 'tcx> {
self.hash_name(&name.node);
self.hash_exprs(args);
}
ExprRange(ref b, ref e) => {
let c: fn(_, _) -> _ = ExprRange;
c.hash(&mut self.s);
if let Some(ref b) = *b {
self.hash_expr(b);
}
if let Some(ref e) = *e {
self.hash_expr(e);
}
}
ExprRepeat(ref e, ref l) => {
let c: fn(_, _) -> _ = ExprRepeat;
c.hash(&mut self.s);

60
src/utils/mod.rs
View File

@ -9,7 +9,7 @@ use std::borrow::Cow;
use std::mem;
use std::ops::{Deref, DerefMut};
use std::str::FromStr;
use syntax::ast::{self, LitKind};
use syntax::ast::{self, LitKind, RangeLimits};
use syntax::codemap::{ExpnInfo, Span, ExpnFormat};
use syntax::errors::DiagnosticBuilder;
use syntax::ptr::P;
@ -40,6 +40,12 @@ pub const LL_PATH: [&'static str; 3] = ["collections", "linked_list", "LinkedLis
pub const MUTEX_PATH: [&'static str; 4] = ["std", "sync", "mutex", "Mutex"];
pub const OPEN_OPTIONS_PATH: [&'static str; 3] = ["std", "fs", "OpenOptions"];
pub const OPTION_PATH: [&'static str; 3] = ["core", "option", "Option"];
pub const RANGE_FROM_PATH: [&'static str; 3] = ["std", "ops", "RangeFrom"];
pub const RANGE_FULL_PATH: [&'static str; 3] = ["std", "ops", "RangeFull"];
pub const RANGE_INCLUSIVE_NON_EMPTY_PATH: [&'static str; 4] = ["std", "ops", "RangeInclusive", "NonEmpty"];
pub const RANGE_PATH: [&'static str; 3] = ["std", "ops", "Range"];
pub const RANGE_TO_INCLUSIVE_PATH: [&'static str; 3] = ["std", "ops", "RangeToInclusive"];
pub const RANGE_TO_PATH: [&'static str; 3] = ["std", "ops", "RangeTo"];
pub const REGEX_NEW_PATH: [&'static str; 3] = ["regex", "Regex", "new"];
pub const RESULT_PATH: [&'static str; 3] = ["core", "result", "Result"];
pub const STRING_PATH: [&'static str; 3] = ["collections", "string", "String"];
@ -673,3 +679,55 @@ pub fn camel_case_from(s: &str) -> usize {
}
last_i
}
/// Represents a range akin to `ast::ExprKind::Range`.
pub struct UnsugaredRange<'a> {
pub start: Option<&'a Expr>,
pub end: Option<&'a Expr>,
pub limits: RangeLimits,
}
/// Unsugar a `hir` range.
pub fn unsugar_range(expr: &Expr) -> Option<UnsugaredRange> {
// To be removed when ranges get stable.
fn unwrap_unstable(expr: &Expr) -> &Expr {
if let ExprBlock(ref block) = expr.node {
if block.rules == BlockCheckMode::PushUnstableBlock || block.rules == BlockCheckMode::PopUnstableBlock {
if let Some(ref expr) = block.expr {
return expr;
}
}
}
expr
}
fn get_field<'a>(name: &str, fields: &'a [Field]) -> Option<&'a Expr> {
let expr = &fields.iter()
.find(|field| field.name.node.as_str() == name)
.unwrap_or_else(|| panic!("missing {} field for range", name))
.expr;
Some(unwrap_unstable(expr))
}
if let ExprStruct(ref path, ref fields, None) = unwrap_unstable(&expr).node {
if match_path(path, &RANGE_FROM_PATH) {
Some(UnsugaredRange { start: get_field("start", fields), end: None, limits: RangeLimits::HalfOpen })
} else if match_path(path, &RANGE_FULL_PATH) {
Some(UnsugaredRange { start: None, end: None, limits: RangeLimits::HalfOpen })
} else if match_path(path, &RANGE_INCLUSIVE_NON_EMPTY_PATH) {
Some(UnsugaredRange { start: get_field("start", fields), end: get_field("end", fields), limits: RangeLimits::Closed })
} else if match_path(path, &RANGE_PATH) {
Some(UnsugaredRange { start: get_field("start", fields), end: get_field("end", fields), limits: RangeLimits::HalfOpen })
} else if match_path(path, &RANGE_TO_INCLUSIVE_PATH) {
Some(UnsugaredRange { start: None, end: get_field("end", fields), limits: RangeLimits::Closed })
} else if match_path(path, &RANGE_TO_PATH) {
Some(UnsugaredRange { start: None, end: get_field("end", fields), limits: RangeLimits::HalfOpen })
} else {
None
}
} else {
None
}
}

32
tests/compile-fail/copies.rs
View File

@ -1,4 +1,4 @@
#![feature(plugin)]
#![feature(plugin, inclusive_range_syntax)]
#![plugin(clippy)]
#![allow(dead_code, no_effect)]
@ -10,16 +10,46 @@
fn bar<T>(_: T) {}
fn foo() -> bool { unimplemented!() }
struct Foo {
bar: u8,
}
#[deny(if_same_then_else)]
#[deny(match_same_arms)]
fn if_same_then_else() -> Result<&'static str, ()> {
if true {
Foo { bar: 42 };
0..10;
..;
0..;
..10;
0...10;
foo();
}
else { //~ERROR this `if` has identical blocks
Foo { bar: 42 };
0..10;
..;
0..;
..10;
0...10;
foo();
}
if true {
Foo { bar: 42 };
}
else {
Foo { bar: 43 };
}
if true {
0..10;
}
else {
0...10;
}
if true {
foo();
foo();

3
tests/compile-fail/no_effect.rs
View File

@ -1,4 +1,4 @@
#![feature(plugin, box_syntax)]
#![feature(plugin, box_syntax, inclusive_range_syntax)]
#![plugin(clippy)]
#![deny(no_effect)]
@ -39,6 +39,7 @@ fn main() {
5..; //~ERROR statement with no effect
..5; //~ERROR statement with no effect
5..6; //~ERROR statement with no effect
5...6; //~ERROR statement with no effect
[42, 55]; //~ERROR statement with no effect
[42, 55][1]; //~ERROR statement with no effect
(42, 55).1; //~ERROR statement with no effect