/
builtin.rs
2116 lines (1866 loc) · 70.6 KB
/
builtin.rs
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// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
//! Lints built in to rustc.
//!
//! This is a sibling of `lint::context` in order to ensure that
//! lints implemented here use the same public API as lint plugins.
//!
//! To add a new lint to rustc, declare it here using `declare_lint!()`.
//! Then add code to emit the new lint in the appropriate circumstances.
//! You can do that in an existing `LintPass` if it makes sense, or in
//! a new `LintPass`, or using `Session::add_lint` elsewhere in the
//! compiler. Only do the latter if the check can't be written cleanly
//! as a `LintPass`.
//!
//! If you define a new `LintPass`, you will also need to add it to the
//! `add_builtin!` or `add_builtin_with_new!` invocation in `context.rs`.
//! Use the former for unit-like structs and the latter for structs with
//! a `pub fn new()`.
use self::MethodContext::*;
use metadata::csearch;
use middle::def::*;
use middle::subst::Substs;
use middle::ty::{self, Ty};
use middle::{def, pat_util, stability};
use middle::const_eval::{eval_const_expr_partial, const_int, const_uint};
use middle::cfg;
use util::ppaux::{ty_to_string};
use util::nodemap::{FnvHashMap, NodeSet};
use lint::{Level, Context, LintPass, LintArray, Lint};
use std::collections::BitvSet;
use std::collections::hash_map::Entry::{Occupied, Vacant};
use std::num::SignedInt;
use std::{cmp, slice};
use std::{i8, i16, i32, i64, u8, u16, u32, u64, f32, f64};
use syntax::{abi, ast, ast_map};
use syntax::ast_util::is_shift_binop;
use syntax::attr::{self, AttrMetaMethods};
use syntax::codemap::{self, Span};
use syntax::parse::token;
use syntax::ast::{TyIs, TyUs, TyI8, TyU8, TyI16, TyU16, TyI32, TyU32, TyI64, TyU64};
use syntax::ast_util;
use syntax::ptr::P;
use syntax::visit::{self, Visitor};
declare_lint! {
WHILE_TRUE,
Warn,
"suggest using `loop { }` instead of `while true { }`"
}
#[derive(Copy)]
pub struct WhileTrue;
impl LintPass for WhileTrue {
fn get_lints(&self) -> LintArray {
lint_array!(WHILE_TRUE)
}
fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
if let ast::ExprWhile(ref cond, _, _) = e.node {
if let ast::ExprLit(ref lit) = cond.node {
if let ast::LitBool(true) = lit.node {
cx.span_lint(WHILE_TRUE, e.span,
"denote infinite loops with loop { ... }");
}
}
}
}
}
declare_lint! {
UNUSED_TYPECASTS,
Allow,
"detects unnecessary type casts that can be removed"
}
#[derive(Copy)]
pub struct UnusedCasts;
impl LintPass for UnusedCasts {
fn get_lints(&self) -> LintArray {
lint_array!(UNUSED_TYPECASTS)
}
fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
if let ast::ExprCast(ref expr, ref ty) = e.node {
let t_t = ty::expr_ty(cx.tcx, e);
if ty::expr_ty(cx.tcx, &**expr) == t_t {
cx.span_lint(UNUSED_TYPECASTS, ty.span, "unnecessary type cast");
}
}
}
}
declare_lint! {
UNSIGNED_NEGATION,
Warn,
"using an unary minus operator on unsigned type"
}
declare_lint! {
UNUSED_COMPARISONS,
Warn,
"comparisons made useless by limits of the types involved"
}
declare_lint! {
OVERFLOWING_LITERALS,
Warn,
"literal out of range for its type"
}
declare_lint! {
EXCEEDING_BITSHIFTS,
Deny,
"shift exceeds the type's number of bits"
}
#[derive(Copy)]
pub struct TypeLimits {
/// Id of the last visited negated expression
negated_expr_id: ast::NodeId,
}
impl TypeLimits {
pub fn new() -> TypeLimits {
TypeLimits {
negated_expr_id: -1,
}
}
}
impl LintPass for TypeLimits {
fn get_lints(&self) -> LintArray {
lint_array!(UNSIGNED_NEGATION, UNUSED_COMPARISONS, OVERFLOWING_LITERALS,
EXCEEDING_BITSHIFTS)
}
fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
match e.node {
ast::ExprUnary(ast::UnNeg, ref expr) => {
match expr.node {
ast::ExprLit(ref lit) => {
match lit.node {
ast::LitInt(_, ast::UnsignedIntLit(_)) => {
cx.span_lint(UNSIGNED_NEGATION, e.span,
"negation of unsigned int literal may \
be unintentional");
},
_ => ()
}
},
_ => {
let t = ty::expr_ty(cx.tcx, &**expr);
match t.sty {
ty::ty_uint(_) => {
cx.span_lint(UNSIGNED_NEGATION, e.span,
"negation of unsigned int variable may \
be unintentional");
},
_ => ()
}
}
};
// propagate negation, if the negation itself isn't negated
if self.negated_expr_id != e.id {
self.negated_expr_id = expr.id;
}
},
ast::ExprParen(ref expr) if self.negated_expr_id == e.id => {
self.negated_expr_id = expr.id;
},
ast::ExprBinary(binop, ref l, ref r) => {
if is_comparison(binop) && !check_limits(cx.tcx, binop, &**l, &**r) {
cx.span_lint(UNUSED_COMPARISONS, e.span,
"comparison is useless due to type limits");
}
if is_shift_binop(binop.node) {
let opt_ty_bits = match ty::expr_ty(cx.tcx, &**l).sty {
ty::ty_int(t) => Some(int_ty_bits(t, cx.sess().target.int_type)),
ty::ty_uint(t) => Some(uint_ty_bits(t, cx.sess().target.uint_type)),
_ => None
};
if let Some(bits) = opt_ty_bits {
let exceeding = if let ast::ExprLit(ref lit) = r.node {
if let ast::LitInt(shift, _) = lit.node { shift >= bits }
else { false }
} else {
match eval_const_expr_partial(cx.tcx, &**r) {
Ok(const_int(shift)) => { shift as u64 >= bits },
Ok(const_uint(shift)) => { shift >= bits },
_ => { false }
}
};
if exceeding {
cx.span_lint(EXCEEDING_BITSHIFTS, e.span,
"bitshift exceeds the type's number of bits");
}
};
}
},
ast::ExprLit(ref lit) => {
match ty::expr_ty(cx.tcx, e).sty {
ty::ty_int(t) => {
match lit.node {
ast::LitInt(v, ast::SignedIntLit(_, ast::Plus)) |
ast::LitInt(v, ast::UnsuffixedIntLit(ast::Plus)) => {
let int_type = if let ast::TyIs(_) = t {
cx.sess().target.int_type
} else { t };
let (min, max) = int_ty_range(int_type);
let negative = self.negated_expr_id == e.id;
if (negative && v > (min.abs() as u64)) ||
(!negative && v > (max.abs() as u64)) {
cx.span_lint(OVERFLOWING_LITERALS, e.span,
&*format!("literal out of range for {:?}", t));
return;
}
}
_ => panic!()
};
},
ty::ty_uint(t) => {
let uint_type = if let ast::TyUs(_) = t {
cx.sess().target.uint_type
} else { t };
let (min, max) = uint_ty_range(uint_type);
let lit_val: u64 = match lit.node {
ast::LitByte(_v) => return, // _v is u8, within range by definition
ast::LitInt(v, _) => v,
_ => panic!()
};
if lit_val < min || lit_val > max {
cx.span_lint(OVERFLOWING_LITERALS, e.span,
&*format!("literal out of range for {:?}", t));
}
},
ty::ty_float(t) => {
let (min, max) = float_ty_range(t);
let lit_val: f64 = match lit.node {
ast::LitFloat(ref v, _) |
ast::LitFloatUnsuffixed(ref v) => {
match v.parse().ok() {
Some(f) => f,
None => return
}
}
_ => panic!()
};
if lit_val < min || lit_val > max {
cx.span_lint(OVERFLOWING_LITERALS, e.span,
&*format!("literal out of range for {:?}", t));
}
},
_ => ()
};
},
_ => ()
};
fn is_valid<T:cmp::PartialOrd>(binop: ast::BinOp, v: T,
min: T, max: T) -> bool {
match binop.node {
ast::BiLt => v > min && v <= max,
ast::BiLe => v >= min && v < max,
ast::BiGt => v >= min && v < max,
ast::BiGe => v > min && v <= max,
ast::BiEq | ast::BiNe => v >= min && v <= max,
_ => panic!()
}
}
fn rev_binop(binop: ast::BinOp) -> ast::BinOp {
codemap::respan(binop.span, match binop.node {
ast::BiLt => ast::BiGt,
ast::BiLe => ast::BiGe,
ast::BiGt => ast::BiLt,
ast::BiGe => ast::BiLe,
_ => return binop
})
}
// for int & uint, be conservative with the warnings, so that the
// warnings are consistent between 32- and 64-bit platforms
fn int_ty_range(int_ty: ast::IntTy) -> (i64, i64) {
match int_ty {
ast::TyIs(_) => (i64::MIN, i64::MAX),
ast::TyI8 => (i8::MIN as i64, i8::MAX as i64),
ast::TyI16 => (i16::MIN as i64, i16::MAX as i64),
ast::TyI32 => (i32::MIN as i64, i32::MAX as i64),
ast::TyI64 => (i64::MIN, i64::MAX)
}
}
fn uint_ty_range(uint_ty: ast::UintTy) -> (u64, u64) {
match uint_ty {
ast::TyUs(_) => (u64::MIN, u64::MAX),
ast::TyU8 => (u8::MIN as u64, u8::MAX as u64),
ast::TyU16 => (u16::MIN as u64, u16::MAX as u64),
ast::TyU32 => (u32::MIN as u64, u32::MAX as u64),
ast::TyU64 => (u64::MIN, u64::MAX)
}
}
fn float_ty_range(float_ty: ast::FloatTy) -> (f64, f64) {
match float_ty {
ast::TyF32 => (f32::MIN_VALUE as f64, f32::MAX_VALUE as f64),
ast::TyF64 => (f64::MIN_VALUE, f64::MAX_VALUE)
}
}
fn int_ty_bits(int_ty: ast::IntTy, target_int_ty: ast::IntTy) -> u64 {
match int_ty {
ast::TyIs(_) => int_ty_bits(target_int_ty, target_int_ty),
ast::TyI8 => i8::BITS as u64,
ast::TyI16 => i16::BITS as u64,
ast::TyI32 => i32::BITS as u64,
ast::TyI64 => i64::BITS as u64
}
}
fn uint_ty_bits(uint_ty: ast::UintTy, target_uint_ty: ast::UintTy) -> u64 {
match uint_ty {
ast::TyUs(_) => uint_ty_bits(target_uint_ty, target_uint_ty),
ast::TyU8 => u8::BITS as u64,
ast::TyU16 => u16::BITS as u64,
ast::TyU32 => u32::BITS as u64,
ast::TyU64 => u64::BITS as u64
}
}
fn check_limits(tcx: &ty::ctxt, binop: ast::BinOp,
l: &ast::Expr, r: &ast::Expr) -> bool {
let (lit, expr, swap) = match (&l.node, &r.node) {
(&ast::ExprLit(_), _) => (l, r, true),
(_, &ast::ExprLit(_)) => (r, l, false),
_ => return true
};
// Normalize the binop so that the literal is always on the RHS in
// the comparison
let norm_binop = if swap { rev_binop(binop) } else { binop };
match ty::expr_ty(tcx, expr).sty {
ty::ty_int(int_ty) => {
let (min, max) = int_ty_range(int_ty);
let lit_val: i64 = match lit.node {
ast::ExprLit(ref li) => match li.node {
ast::LitInt(v, ast::SignedIntLit(_, ast::Plus)) |
ast::LitInt(v, ast::UnsuffixedIntLit(ast::Plus)) => v as i64,
ast::LitInt(v, ast::SignedIntLit(_, ast::Minus)) |
ast::LitInt(v, ast::UnsuffixedIntLit(ast::Minus)) => -(v as i64),
_ => return true
},
_ => panic!()
};
is_valid(norm_binop, lit_val, min, max)
}
ty::ty_uint(uint_ty) => {
let (min, max): (u64, u64) = uint_ty_range(uint_ty);
let lit_val: u64 = match lit.node {
ast::ExprLit(ref li) => match li.node {
ast::LitInt(v, _) => v,
_ => return true
},
_ => panic!()
};
is_valid(norm_binop, lit_val, min, max)
}
_ => true
}
}
fn is_comparison(binop: ast::BinOp) -> bool {
match binop.node {
ast::BiEq | ast::BiLt | ast::BiLe |
ast::BiNe | ast::BiGe | ast::BiGt => true,
_ => false
}
}
}
}
declare_lint! {
IMPROPER_CTYPES,
Warn,
"proper use of libc types in foreign modules"
}
struct ImproperCTypesVisitor<'a, 'tcx: 'a> {
cx: &'a Context<'a, 'tcx>
}
impl<'a, 'tcx> ImproperCTypesVisitor<'a, 'tcx> {
fn check_def(&mut self, sp: Span, ty_id: ast::NodeId, path_id: ast::NodeId) {
match self.cx.tcx.def_map.borrow()[path_id].clone() {
def::DefPrimTy(ast::TyInt(ast::TyIs(_))) => {
self.cx.span_lint(IMPROPER_CTYPES, sp,
"found rust type `isize` in foreign module, while \
libc::c_int or libc::c_long should be used");
}
def::DefPrimTy(ast::TyUint(ast::TyUs(_))) => {
self.cx.span_lint(IMPROPER_CTYPES, sp,
"found rust type `usize` in foreign module, while \
libc::c_uint or libc::c_ulong should be used");
}
def::DefTy(..) => {
let tty = match self.cx.tcx.ast_ty_to_ty_cache.borrow().get(&ty_id) {
Some(&ty::atttce_resolved(t)) => t,
_ => panic!("ast_ty_to_ty_cache was incomplete after typeck!")
};
if !ty::is_ffi_safe(self.cx.tcx, tty) {
self.cx.span_lint(IMPROPER_CTYPES, sp,
"found type without foreign-function-safe
representation annotation in foreign module, consider \
adding a #[repr(...)] attribute to the type");
}
}
_ => ()
}
}
}
impl<'a, 'tcx, 'v> Visitor<'v> for ImproperCTypesVisitor<'a, 'tcx> {
fn visit_ty(&mut self, ty: &ast::Ty) {
match ty.node {
ast::TyPath(_, id) => self.check_def(ty.span, ty.id, id),
_ => (),
}
visit::walk_ty(self, ty);
}
}
#[derive(Copy)]
pub struct ImproperCTypes;
impl LintPass for ImproperCTypes {
fn get_lints(&self) -> LintArray {
lint_array!(IMPROPER_CTYPES)
}
fn check_item(&mut self, cx: &Context, it: &ast::Item) {
fn check_ty(cx: &Context, ty: &ast::Ty) {
let mut vis = ImproperCTypesVisitor { cx: cx };
vis.visit_ty(ty);
}
fn check_foreign_fn(cx: &Context, decl: &ast::FnDecl) {
for input in &decl.inputs {
check_ty(cx, &*input.ty);
}
if let ast::Return(ref ret_ty) = decl.output {
check_ty(cx, &**ret_ty);
}
}
match it.node {
ast::ItemForeignMod(ref nmod) if nmod.abi != abi::RustIntrinsic => {
for ni in &nmod.items {
match ni.node {
ast::ForeignItemFn(ref decl, _) => check_foreign_fn(cx, &**decl),
ast::ForeignItemStatic(ref t, _) => check_ty(cx, &**t)
}
}
}
_ => (),
}
}
}
declare_lint! {
BOX_POINTERS,
Allow,
"use of owned (Box type) heap memory"
}
#[derive(Copy)]
pub struct BoxPointers;
impl BoxPointers {
fn check_heap_type<'a, 'tcx>(&self, cx: &Context<'a, 'tcx>,
span: Span, ty: Ty<'tcx>) {
let mut n_uniq = 0us;
ty::fold_ty(cx.tcx, ty, |t| {
match t.sty {
ty::ty_uniq(_) => {
n_uniq += 1;
}
_ => ()
};
t
});
if n_uniq > 0 {
let s = ty_to_string(cx.tcx, ty);
let m = format!("type uses owned (Box type) pointers: {}", s);
cx.span_lint(BOX_POINTERS, span, &m[]);
}
}
}
impl LintPass for BoxPointers {
fn get_lints(&self) -> LintArray {
lint_array!(BOX_POINTERS)
}
fn check_item(&mut self, cx: &Context, it: &ast::Item) {
match it.node {
ast::ItemFn(..) |
ast::ItemTy(..) |
ast::ItemEnum(..) |
ast::ItemStruct(..) =>
self.check_heap_type(cx, it.span,
ty::node_id_to_type(cx.tcx, it.id)),
_ => ()
}
// If it's a struct, we also have to check the fields' types
match it.node {
ast::ItemStruct(ref struct_def, _) => {
for struct_field in &struct_def.fields {
self.check_heap_type(cx, struct_field.span,
ty::node_id_to_type(cx.tcx, struct_field.node.id));
}
}
_ => ()
}
}
fn check_expr(&mut self, cx: &Context, e: &ast::Expr) {
let ty = ty::expr_ty(cx.tcx, e);
self.check_heap_type(cx, e.span, ty);
}
}
declare_lint! {
RAW_POINTER_DERIVE,
Warn,
"uses of #[derive] with raw pointers are rarely correct"
}
struct RawPtrDeriveVisitor<'a, 'tcx: 'a> {
cx: &'a Context<'a, 'tcx>
}
impl<'a, 'tcx, 'v> Visitor<'v> for RawPtrDeriveVisitor<'a, 'tcx> {
fn visit_ty(&mut self, ty: &ast::Ty) {
static MSG: &'static str = "use of `#[derive]` with a raw pointer";
if let ast::TyPtr(..) = ty.node {
self.cx.span_lint(RAW_POINTER_DERIVE, ty.span, MSG);
}
visit::walk_ty(self, ty);
}
// explicit override to a no-op to reduce code bloat
fn visit_expr(&mut self, _: &ast::Expr) {}
fn visit_block(&mut self, _: &ast::Block) {}
}
pub struct RawPointerDerive {
checked_raw_pointers: NodeSet,
}
impl RawPointerDerive {
pub fn new() -> RawPointerDerive {
RawPointerDerive {
checked_raw_pointers: NodeSet(),
}
}
}
impl LintPass for RawPointerDerive {
fn get_lints(&self) -> LintArray {
lint_array!(RAW_POINTER_DERIVE)
}
fn check_item(&mut self, cx: &Context, item: &ast::Item) {
if !attr::contains_name(&item.attrs[], "automatically_derived") {
return
}
let did = match item.node {
ast::ItemImpl(_, _, _, ref t_ref_opt, _, _) => {
// Deriving the Copy trait does not cause a warning
if let &Some(ref trait_ref) = t_ref_opt {
let def_id = ty::trait_ref_to_def_id(cx.tcx, trait_ref);
if Some(def_id) == cx.tcx.lang_items.copy_trait() {
return
}
}
match ty::node_id_to_type(cx.tcx, item.id).sty {
ty::ty_enum(did, _) => did,
ty::ty_struct(did, _) => did,
_ => return,
}
}
_ => return,
};
if !ast_util::is_local(did) { return }
let item = match cx.tcx.map.find(did.node) {
Some(ast_map::NodeItem(item)) => item,
_ => return,
};
if !self.checked_raw_pointers.insert(item.id) { return }
match item.node {
ast::ItemStruct(..) | ast::ItemEnum(..) => {
let mut visitor = RawPtrDeriveVisitor { cx: cx };
visit::walk_item(&mut visitor, &*item);
}
_ => {}
}
}
}
declare_lint! {
UNUSED_ATTRIBUTES,
Warn,
"detects attributes that were not used by the compiler"
}
#[derive(Copy)]
pub struct UnusedAttributes;
impl LintPass for UnusedAttributes {
fn get_lints(&self) -> LintArray {
lint_array!(UNUSED_ATTRIBUTES)
}
fn check_attribute(&mut self, cx: &Context, attr: &ast::Attribute) {
static ATTRIBUTE_WHITELIST: &'static [&'static str] = &[
// FIXME: #14408 whitelist docs since rustdoc looks at them
"doc",
// FIXME: #14406 these are processed in trans, which happens after the
// lint pass
"cold",
"export_name",
"inline",
"link",
"link_name",
"link_section",
"linkage",
"no_builtins",
"no_mangle",
"no_split_stack",
"no_stack_check",
"packed",
"static_assert",
"thread_local",
"no_debug",
"omit_gdb_pretty_printer_section",
"unsafe_no_drop_flag",
// used in resolve
"prelude_import",
// FIXME: #14407 these are only looked at on-demand so we can't
// guarantee they'll have already been checked
"deprecated",
"must_use",
"stable",
"unstable",
"rustc_on_unimplemented",
// FIXME: #19470 this shouldn't be needed forever
"old_orphan_check",
"old_impl_check",
"rustc_paren_sugar", // FIXME: #18101 temporary unboxed closure hack
];
static CRATE_ATTRS: &'static [&'static str] = &[
"crate_name",
"crate_type",
"feature",
"no_start",
"no_main",
"no_std",
"no_builtins",
];
for &name in ATTRIBUTE_WHITELIST {
if attr.check_name(name) {
break;
}
}
if !attr::is_used(attr) {
cx.span_lint(UNUSED_ATTRIBUTES, attr.span, "unused attribute");
if CRATE_ATTRS.contains(&&attr.name()[]) {
let msg = match attr.node.style {
ast::AttrOuter => "crate-level attribute should be an inner \
attribute: add an exclamation mark: #![foo]",
ast::AttrInner => "crate-level attribute should be in the \
root module",
};
cx.span_lint(UNUSED_ATTRIBUTES, attr.span, msg);
}
}
}
}
declare_lint! {
pub PATH_STATEMENTS,
Warn,
"path statements with no effect"
}
#[derive(Copy)]
pub struct PathStatements;
impl LintPass for PathStatements {
fn get_lints(&self) -> LintArray {
lint_array!(PATH_STATEMENTS)
}
fn check_stmt(&mut self, cx: &Context, s: &ast::Stmt) {
match s.node {
ast::StmtSemi(ref expr, _) => {
match expr.node {
ast::ExprPath(_) => cx.span_lint(PATH_STATEMENTS, s.span,
"path statement with no effect"),
_ => ()
}
}
_ => ()
}
}
}
declare_lint! {
pub UNUSED_MUST_USE,
Warn,
"unused result of a type flagged as #[must_use]"
}
declare_lint! {
pub UNUSED_RESULTS,
Allow,
"unused result of an expression in a statement"
}
#[derive(Copy)]
pub struct UnusedResults;
impl LintPass for UnusedResults {
fn get_lints(&self) -> LintArray {
lint_array!(UNUSED_MUST_USE, UNUSED_RESULTS)
}
fn check_stmt(&mut self, cx: &Context, s: &ast::Stmt) {
let expr = match s.node {
ast::StmtSemi(ref expr, _) => &**expr,
_ => return
};
if let ast::ExprRet(..) = expr.node {
return;
}
let t = ty::expr_ty(cx.tcx, expr);
let mut warned = false;
match t.sty {
ty::ty_tup(ref tys) if tys.is_empty() => return,
ty::ty_bool => return,
ty::ty_struct(did, _) |
ty::ty_enum(did, _) => {
if ast_util::is_local(did) {
if let ast_map::NodeItem(it) = cx.tcx.map.get(did.node) {
warned |= check_must_use(cx, &it.attrs[], s.span);
}
} else {
let attrs = csearch::get_item_attrs(&cx.sess().cstore, did);
warned |= check_must_use(cx, &attrs[], s.span);
}
}
_ => {}
}
if !warned {
cx.span_lint(UNUSED_RESULTS, s.span, "unused result");
}
fn check_must_use(cx: &Context, attrs: &[ast::Attribute], sp: Span) -> bool {
for attr in attrs {
if attr.check_name("must_use") {
let mut msg = "unused result which must be used".to_string();
// check for #[must_use="..."]
match attr.value_str() {
None => {}
Some(s) => {
msg.push_str(": ");
msg.push_str(&s[]);
}
}
cx.span_lint(UNUSED_MUST_USE, sp, &msg[]);
return true;
}
}
false
}
}
}
declare_lint! {
pub NON_CAMEL_CASE_TYPES,
Warn,
"types, variants, traits and type parameters should have camel case names"
}
#[derive(Copy)]
pub struct NonCamelCaseTypes;
impl NonCamelCaseTypes {
fn check_case(&self, cx: &Context, sort: &str, ident: ast::Ident, span: Span) {
fn is_camel_case(ident: ast::Ident) -> bool {
let ident = token::get_ident(ident);
if ident.is_empty() { return true; }
let ident = ident.trim_matches('_');
// start with a non-lowercase letter rather than non-uppercase
// ones (some scripts don't have a concept of upper/lowercase)
ident.len() > 0 && !ident.char_at(0).is_lowercase() && !ident.contains_char('_')
}
fn to_camel_case(s: &str) -> String {
s.split('_').flat_map(|word| word.chars().enumerate().map(|(i, c)|
if i == 0 { c.to_uppercase() }
else { c }
)).collect()
}
let s = token::get_ident(ident);
if !is_camel_case(ident) {
let c = to_camel_case(&s[]);
let m = if c.is_empty() {
format!("{} `{}` should have a camel case name such as `CamelCase`", sort, s)
} else {
format!("{} `{}` should have a camel case name such as `{}`", sort, s, c)
};
cx.span_lint(NON_CAMEL_CASE_TYPES, span, &m[]);
}
}
}
impl LintPass for NonCamelCaseTypes {
fn get_lints(&self) -> LintArray {
lint_array!(NON_CAMEL_CASE_TYPES)
}
fn check_item(&mut self, cx: &Context, it: &ast::Item) {
let has_extern_repr = it.attrs.iter().map(|attr| {
attr::find_repr_attrs(cx.tcx.sess.diagnostic(), attr).iter()
.any(|r| r == &attr::ReprExtern)
}).any(|x| x);
if has_extern_repr { return }
match it.node {
ast::ItemTy(..) | ast::ItemStruct(..) => {
self.check_case(cx, "type", it.ident, it.span)
}
ast::ItemTrait(..) => {
self.check_case(cx, "trait", it.ident, it.span)
}
ast::ItemEnum(ref enum_definition, _) => {
if has_extern_repr { return }
self.check_case(cx, "type", it.ident, it.span);
for variant in &enum_definition.variants {
self.check_case(cx, "variant", variant.node.name, variant.span);
}
}
_ => ()
}
}
fn check_generics(&mut self, cx: &Context, it: &ast::Generics) {
for gen in &*it.ty_params {
self.check_case(cx, "type parameter", gen.ident, gen.span);
}
}
}
#[derive(PartialEq)]
enum MethodContext {
TraitDefaultImpl,
TraitImpl,
PlainImpl
}
fn method_context(cx: &Context, m: &ast::Method) -> MethodContext {
let did = ast::DefId {
krate: ast::LOCAL_CRATE,
node: m.id
};
match cx.tcx.impl_or_trait_items.borrow().get(&did).cloned() {
None => cx.sess().span_bug(m.span, "missing method descriptor?!"),
Some(md) => {
match md {
ty::MethodTraitItem(md) => {
match md.container {
ty::TraitContainer(..) => TraitDefaultImpl,
ty::ImplContainer(cid) => {
match ty::impl_trait_ref(cx.tcx, cid) {
Some(..) => TraitImpl,
None => PlainImpl
}
}
}
}
ty::TypeTraitItem(typedef) => {
match typedef.container {
ty::TraitContainer(..) => TraitDefaultImpl,
ty::ImplContainer(cid) => {
match ty::impl_trait_ref(cx.tcx, cid) {
Some(..) => TraitImpl,
None => PlainImpl
}
}
}
}
}
}
}
}
declare_lint! {
pub NON_SNAKE_CASE,
Warn,
"methods, functions, lifetime parameters and modules should have snake case names"
}
#[derive(Copy)]
pub struct NonSnakeCase;
impl NonSnakeCase {
fn to_snake_case(mut str: &str) -> String {
let mut words = vec![];
// Preserve leading underscores
str = str.trim_left_matches(|c: char| {
if c == '_' {
words.push(String::new());
true
} else { false }
});
for s in str.split('_') {
let mut last_upper = false;
let mut buf = String::new();
if s.is_empty() { continue; }
for ch in s.chars() {
if !buf.is_empty() && buf != "'"
&& ch.is_uppercase()
&& !last_upper {
words.push(buf);
buf = String::new();
}
last_upper = ch.is_uppercase();
buf.push(ch.to_lowercase());
}
words.push(buf);
}
words.connect("_")
}
fn check_snake_case(&self, cx: &Context, sort: &str, ident: ast::Ident, span: Span) {
fn is_snake_case(ident: ast::Ident) -> bool {
let ident = token::get_ident(ident);
if ident.is_empty() { return true; }
let ident = ident.trim_left_matches('\'');
let ident = ident.trim_matches('_');
let mut allow_underscore = true;
ident.chars().all(|c| {
allow_underscore = match c {
'_' if !allow_underscore => return false,
'_' => false,
c if !c.is_uppercase() => true,
_ => return false,
};
true
})
}
let s = token::get_ident(ident);
if !is_snake_case(ident) {
let sc = NonSnakeCase::to_snake_case(&s[]);
if sc != &s[] {