rust/src/librustc/middle/lint.rs

1685 lines
55 KiB
Rust

// Copyright 2012 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.
use driver::session;
use middle::ty;
use middle::pat_util;
use metadata::csearch;
use util::ppaux::{ty_to_str};
use std::cmp;
use std::hashmap::HashMap;
use std::i16;
use std::i32;
use std::i64;
use std::i8;
use std::u16;
use std::u32;
use std::u64;
use std::u8;
use extra::smallintmap::SmallIntMap;
use syntax::ast_map;
use syntax::attr;
use syntax::attr::{AttrMetaMethods, AttributeMethods};
use syntax::codemap::Span;
use syntax::codemap;
use syntax::parse::token;
use syntax::{ast, ast_util, visit};
use syntax::visit::Visitor;
/**
* A 'lint' check is a kind of miscellaneous constraint that a user _might_
* want to enforce, but might reasonably want to permit as well, on a
* module-by-module basis. They contrast with static constraints enforced by
* other phases of the compiler, which are generally required to hold in order
* to compile the program at all.
*
* The lint checking is all consolidated into one pass which runs just before
* translation to LLVM bytecode. Throughout compilation, lint warnings can be
* added via the `add_lint` method on the Session structure. This requires a
* span and an id of the node that the lint is being added to. The lint isn't
* actually emitted at that time because it is unknown what the actual lint
* level at that location is.
*
* To actually emit lint warnings/errors, a separate pass is used just before
* translation. A context keeps track of the current state of all lint levels.
* Upon entering a node of the ast which can modify the lint settings, the
* previous lint state is pushed onto a stack and the ast is then recursed upon.
* As the ast is traversed, this keeps track of the current lint level for all
* lint attributes.
*
* At each node of the ast which can modify lint attributes, all known lint
* passes are also applied. Each lint pass is a visit::Visitor implementator.
* The visitors are constructed via the lint_*() functions below. There are
* also some lint checks which operate directly on ast nodes (such as
* @ast::item), and those are organized as check_item_*(). Each visitor added
* to the lint context is modified to stop once it reaches a node which could
* alter the lint levels. This means that everything is looked at once and
* only once by every lint pass.
*
* With this all in place, to add a new lint warning, all you need to do is to
* either invoke `add_lint` on the session at the appropriate time, or write a
* lint pass in this module which is just an ast visitor. The context used when
* traversing the ast has a `span_lint` method which only needs the span of the
* item that's being warned about.
*/
#[deriving(Clone, Eq)]
pub enum lint {
ctypes,
cstack,
unused_imports,
unnecessary_qualification,
while_true,
path_statement,
unrecognized_lint,
non_camel_case_types,
non_uppercase_statics,
non_uppercase_pattern_statics,
type_limits,
unused_unsafe,
managed_heap_memory,
owned_heap_memory,
heap_memory,
unused_variable,
dead_assignment,
unused_mut,
unnecessary_allocation,
missing_doc,
unreachable_code,
deprecated,
experimental,
unstable,
warnings,
}
pub fn level_to_str(lv: level) -> &'static str {
match lv {
allow => "allow",
warn => "warn",
deny => "deny",
forbid => "forbid"
}
}
#[deriving(Clone, Eq, Ord)]
pub enum level {
allow, warn, deny, forbid
}
#[deriving(Clone, Eq)]
pub struct LintSpec {
lint: lint,
desc: &'static str,
default: level
}
impl Ord for LintSpec {
fn lt(&self, other: &LintSpec) -> bool { self.default < other.default }
}
pub type LintDict = HashMap<&'static str, LintSpec>;
enum AttributedNode<'self> {
Item(@ast::item),
Method(&'self ast::method),
Crate(&'self ast::Crate),
}
#[deriving(Eq)]
enum LintSource {
Node(Span),
Default,
CommandLine
}
static lint_table: &'static [(&'static str, LintSpec)] = &[
("ctypes",
LintSpec {
lint: ctypes,
desc: "proper use of std::libc types in foreign modules",
default: warn
}),
("cstack",
LintSpec {
lint: cstack,
desc: "only invoke foreign functions from fixedstacksegment fns",
default: deny
}),
("unused_imports",
LintSpec {
lint: unused_imports,
desc: "imports that are never used",
default: warn
}),
("unnecessary_qualification",
LintSpec {
lint: unnecessary_qualification,
desc: "detects unnecessarily qualified names",
default: allow
}),
("while_true",
LintSpec {
lint: while_true,
desc: "suggest using loop { } instead of while(true) { }",
default: warn
}),
("path_statement",
LintSpec {
lint: path_statement,
desc: "path statements with no effect",
default: warn
}),
("unrecognized_lint",
LintSpec {
lint: unrecognized_lint,
desc: "unrecognized lint attribute",
default: warn
}),
("non_camel_case_types",
LintSpec {
lint: non_camel_case_types,
desc: "types, variants and traits should have camel case names",
default: allow
}),
("non_uppercase_statics",
LintSpec {
lint: non_uppercase_statics,
desc: "static constants should have uppercase identifiers",
default: allow
}),
("non_uppercase_pattern_statics",
LintSpec {
lint: non_uppercase_pattern_statics,
desc: "static constants in match patterns should be all caps",
default: warn
}),
("managed_heap_memory",
LintSpec {
lint: managed_heap_memory,
desc: "use of managed (@ type) heap memory",
default: allow
}),
("owned_heap_memory",
LintSpec {
lint: owned_heap_memory,
desc: "use of owned (~ type) heap memory",
default: allow
}),
("heap_memory",
LintSpec {
lint: heap_memory,
desc: "use of any (~ type or @ type) heap memory",
default: allow
}),
("type_limits",
LintSpec {
lint: type_limits,
desc: "comparisons made useless by limits of the types involved",
default: warn
}),
("unused_unsafe",
LintSpec {
lint: unused_unsafe,
desc: "unnecessary use of an `unsafe` block",
default: warn
}),
("unused_variable",
LintSpec {
lint: unused_variable,
desc: "detect variables which are not used in any way",
default: warn
}),
("dead_assignment",
LintSpec {
lint: dead_assignment,
desc: "detect assignments that will never be read",
default: warn
}),
("unused_mut",
LintSpec {
lint: unused_mut,
desc: "detect mut variables which don't need to be mutable",
default: warn
}),
("unnecessary_allocation",
LintSpec {
lint: unnecessary_allocation,
desc: "detects unnecessary allocations that can be eliminated",
default: warn
}),
("missing_doc",
LintSpec {
lint: missing_doc,
desc: "detects missing documentation for public members",
default: allow
}),
("unreachable_code",
LintSpec {
lint: unreachable_code,
desc: "detects unreachable code",
default: warn
}),
("deprecated",
LintSpec {
lint: deprecated,
desc: "detects use of #[deprecated] items",
default: warn
}),
("experimental",
LintSpec {
lint: experimental,
desc: "detects use of #[experimental] items",
default: warn
}),
("unstable",
LintSpec {
lint: unstable,
desc: "detects use of #[unstable] items (incl. items with no stability attribute)",
default: allow
}),
("warnings",
LintSpec {
lint: warnings,
desc: "mass-change the level for lints which produce warnings",
default: warn
}),
];
/*
Pass names should not contain a '-', as the compiler normalizes
'-' to '_' in command-line flags
*/
pub fn get_lint_dict() -> LintDict {
let mut map = HashMap::new();
for &(k, v) in lint_table.iter() {
map.insert(k, v);
}
return map;
}
trait OuterLint {
fn process_item(@mut self, i:@ast::item, e:@mut Context);
fn process_fn(@mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context);
// Returned inner variant will not proceed past subitems.
// Supports decomposition of simple lints into subitem-traversing
// outer lint visitor and subitem-stopping inner lint visitor.
fn inner_variant(@mut self) -> @mut InnerLint;
}
trait InnerLint {
fn descend_item(@mut self, i:&ast::item, e:@mut Context);
fn descend_crate(@mut self, crate: &ast::Crate, env: @mut Context);
fn descend_fn(@mut self,
function_kind: &visit::fn_kind,
function_declaration: &ast::fn_decl,
function_body: &ast::Block,
sp: Span,
id: ast::NodeId,
env: @mut Context);
}
impl<V:Visitor<@mut Context>> InnerLint for V {
fn descend_item(@mut self, i:&ast::item, e:@mut Context) {
visit::walk_item(self, i, e);
}
fn descend_crate(@mut self, crate: &ast::Crate, env: @mut Context) {
visit::walk_crate(self, crate, env);
}
fn descend_fn(@mut self, fk: &visit::fn_kind, fd: &ast::fn_decl, fb: &ast::Block,
sp: Span, id: ast::NodeId, env: @mut Context) {
visit::walk_fn(self, fk, fd, fb, sp, id, env);
}
}
enum AnyVisitor {
// This is a pair so every visitor can visit every node. When a lint pass
// is registered, another visitor is created which stops at all items
// which can alter the attributes of the ast. This "item stopping visitor"
// is the second element of the pair, while the original visitor is the
// first element. This means that when visiting a node, the original
// recursive call can use the original visitor's method, although the
// recursing visitor supplied to the method is the item stopping visitor.
OldVisitor(@mut OuterLint, @mut InnerLint),
NewVisitor(@mut visit::Visitor<()>),
}
struct Context {
// All known lint modes (string versions)
dict: @LintDict,
// Current levels of each lint warning
curr: SmallIntMap<(level, LintSource)>,
// context we're checking in (used to access fields like sess)
tcx: ty::ctxt,
// Just a simple flag if we're currently recursing into a trait
// implementation. This is only used by the lint_missing_doc() pass
in_trait_impl: bool,
// Another flag for doc lint emissions. Does some parent of the current node
// have the doc(hidden) attribute? Treating this as allow(missing_doc) would
// play badly with forbid(missing_doc) when it shouldn't.
doc_hidden: bool,
// When recursing into an attributed node of the ast which modifies lint
// levels, this stack keeps track of the previous lint levels of whatever
// was modified.
lint_stack: ~[(lint, level, LintSource)],
// Each of these visitors represents a lint pass. A number of the lint
// attributes are registered by adding a visitor to iterate over the ast.
// Others operate directly on @ast::item structures (or similar). Finally,
// others still are added to the Session object via `add_lint`, and these
// are all passed with the lint_session visitor.
visitors: ~[AnyVisitor],
}
impl Context {
fn get_level(&self, lint: lint) -> level {
match self.curr.find(&(lint as uint)) {
Some(&(lvl, _)) => lvl,
None => allow
}
}
fn get_source(&self, lint: lint) -> LintSource {
match self.curr.find(&(lint as uint)) {
Some(&(_, src)) => src,
None => Default
}
}
fn set_level(&mut self, lint: lint, level: level, src: LintSource) {
if level == allow {
self.curr.remove(&(lint as uint));
} else {
self.curr.insert(lint as uint, (level, src));
}
}
fn lint_to_str(&self, lint: lint) -> &'static str {
for (k, v) in self.dict.iter() {
if v.lint == lint {
return *k;
}
}
fail2!("unregistered lint {:?}", lint);
}
fn span_lint(&self, lint: lint, span: Span, msg: &str) {
let (level, src) = match self.curr.find(&(lint as uint)) {
None => { return }
Some(&(warn, src)) => (self.get_level(warnings), src),
Some(&pair) => pair,
};
if level == allow { return }
let mut note = None;
let msg = match src {
Default | CommandLine => {
format!("{} [-{} {}{}]", msg, match level {
warn => 'W', deny => 'D', forbid => 'F',
allow => fail2!()
}, self.lint_to_str(lint).replace("_", "-"),
if src == Default { " (default)" } else { "" })
},
Node(src) => {
note = Some(src);
msg.to_str()
}
};
match level {
warn => { self.tcx.sess.span_warn(span, msg); }
deny | forbid => { self.tcx.sess.span_err(span, msg); }
allow => fail2!(),
}
for &span in note.iter() {
self.tcx.sess.span_note(span, "lint level defined here");
}
}
/**
* Merge the lints specified by any lint attributes into the
* current lint context, call the provided function, then reset the
* lints in effect to their previous state.
*/
fn with_lint_attrs(@mut self, attrs: &[ast::Attribute], f: &fn()) {
// Parse all of the lint attributes, and then add them all to the
// current dictionary of lint information. Along the way, keep a history
// of what we changed so we can roll everything back after invoking the
// specified closure
let mut pushed = 0u;
do each_lint(self.tcx.sess, attrs) |meta, level, lintname| {
match self.dict.find_equiv(&lintname) {
None => {
self.span_lint(
unrecognized_lint,
meta.span,
format!("unknown `{}` attribute: `{}`",
level_to_str(level), lintname));
}
Some(lint) => {
let lint = lint.lint;
let now = self.get_level(lint);
if now == forbid && level != forbid {
self.tcx.sess.span_err(meta.span,
format!("{}({}) overruled by outer forbid({})",
level_to_str(level),
lintname, lintname));
} else if now != level {
let src = self.get_source(lint);
self.lint_stack.push((lint, now, src));
pushed += 1;
self.set_level(lint, level, Node(meta.span));
}
}
}
true
};
// detect doc(hidden)
let mut doc_hidden = do attrs.iter().any |attr| {
"doc" == attr.name() &&
match attr.meta_item_list() {
Some(l) => attr::contains_name(l, "hidden"),
None => false // not of the form #[doc(...)]
}
};
if doc_hidden && !self.doc_hidden {
self.doc_hidden = true;
} else {
doc_hidden = false;
}
f();
// rollback
if doc_hidden && self.doc_hidden {
self.doc_hidden = false;
}
do pushed.times {
let (lint, lvl, src) = self.lint_stack.pop();
self.set_level(lint, lvl, src);
}
}
fn add_old_lint(&mut self, v: @mut OuterLint) {
self.visitors.push(OldVisitor(v, v.inner_variant()));
}
fn add_lint(&mut self, v: @mut visit::Visitor<()>) {
self.visitors.push(NewVisitor(v));
}
fn process(@mut self, n: AttributedNode) {
// see comment of the `visitors` field in the struct for why there's a
// pair instead of just one visitor.
match n {
Item(it) => {
for visitor in self.visitors.iter() {
match *visitor {
OldVisitor(orig, stopping) => {
orig.process_item(it, self);
stopping.descend_item(it, self);
}
NewVisitor(new_visitor) => {
let new_visitor = new_visitor;
new_visitor.visit_item(it, ());
}
}
}
}
Crate(c) => {
for visitor in self.visitors.iter() {
match *visitor {
OldVisitor(_, stopping) => {
stopping.descend_crate(c, self)
}
NewVisitor(new_visitor) => {
let mut new_visitor = new_visitor;
visit::walk_crate(&mut new_visitor, c, ())
}
}
}
}
// Can't use visit::walk_method_helper because the
// item_stopping_visitor has overridden visit_fn(&fk_method(... ))
// to be a no-op, so manually invoke visit_fn.
Method(m) => {
for visitor in self.visitors.iter() {
match *visitor {
OldVisitor(orig, stopping) => {
let fk = visit::fk_method(m.ident, &m.generics, m);
orig.process_fn(&fk, &m.decl, &m.body, m.span, m.id, self);
stopping.descend_fn(&fk, &m.decl, &m.body, m.span, m.id, self);
}
NewVisitor(new_visitor) => {
let fk = visit::fk_method(m.ident,
&m.generics,
m);
let new_visitor = new_visitor;
new_visitor.visit_fn(&fk,
&m.decl,
&m.body,
m.span,
m.id,
())
}
}
}
}
}
}
}
pub fn each_lint(sess: session::Session,
attrs: &[ast::Attribute],
f: &fn(@ast::MetaItem, level, @str) -> bool) -> bool {
let xs = [allow, warn, deny, forbid];
for &level in xs.iter() {
let level_name = level_to_str(level);
for attr in attrs.iter().filter(|m| level_name == m.name()) {
let meta = attr.node.value;
let metas = match meta.node {
ast::MetaList(_, ref metas) => metas,
_ => {
sess.span_err(meta.span, "malformed lint attribute");
continue;
}
};
for meta in metas.iter() {
match meta.node {
ast::MetaWord(lintname) => {
if !f(*meta, level, lintname) {
return false;
}
}
_ => {
sess.span_err(meta.span, "malformed lint attribute");
}
}
}
}
}
true
}
trait SubitemStoppableVisitor : Visitor<@mut Context> {
fn is_running_on_items(&mut self) -> bool;
fn visit_item_action(&mut self, _i:@ast::item, _e:@mut Context) {
// fill in with particular action without recursion if desired
}
fn visit_fn_action(&mut self, _fk:&visit::fn_kind, _fd:&ast::fn_decl,
_b:&ast::Block, _s:Span, _n:ast::NodeId, _e:@mut Context) {
// fill in with particular action without recursion if desired
}
// The two OVERRIDE methods:
//
// OVERRIDE_visit_item
// OVERRIDE_visit_fn
//
// *must* be included as initial reimplementations of the standard
// default behavior of visit_item and visit_fn for every impl of
// Visitor, in order to recreate the effect of having two variant
// Outer/Inner behaviors of lint visitors. (See earlier versions
// of this module to see what the original encoding was of this
// emulated behavior.)
fn OVERRIDE_visit_item(&mut self, i:@ast::item, e:@mut Context) {
if self.is_running_on_items() {
self.visit_item_action(i, e);
visit::walk_item(self, i, e);
}
}
fn OVERRIDE_visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
if self.is_running_on_items() {
self.visit_fn_action(fk, fd, b, s, n, e);
visit::walk_fn(self, fk, fd, b, s, n, e);
} else {
match *fk {
visit::fk_method(*) => {}
_ => {
self.visit_fn_action(fk, fd, b, s, n, e);
visit::walk_fn(self, fk, fd, b, s, n, e);
}
}
}
}
}
struct WhileTrueLintVisitor { stopping_on_items: bool }
impl SubitemStoppableVisitor for WhileTrueLintVisitor {
fn is_running_on_items(&mut self) -> bool { !self.stopping_on_items }
}
impl Visitor<@mut Context> for WhileTrueLintVisitor {
fn visit_item(&mut self, i:@ast::item, e:@mut Context) {
self.OVERRIDE_visit_item(i, e);
}
fn visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.OVERRIDE_visit_fn(fk, fd, b, s, n, e);
}
fn visit_expr(&mut self, e:@ast::Expr, cx:@mut Context) {
match e.node {
ast::ExprWhile(cond, _) => {
match cond.node {
ast::ExprLit(@codemap::Spanned {
node: ast::lit_bool(true), _}) =>
{
cx.span_lint(while_true, e.span,
"denote infinite loops with \
loop { ... }");
}
_ => ()
}
}
_ => ()
}
visit::walk_expr(self, e, cx);
}
}
macro_rules! outer_lint_boilerplate_impl(
($Visitor:ident) =>
(
impl OuterLint for $Visitor {
fn process_item(@mut self, i:@ast::item, e:@mut Context) {
self.visit_item_action(i, e);
}
fn process_fn(@mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.visit_fn_action(fk, fd, b, s, n, e);
}
fn inner_variant(@mut self) -> @mut InnerLint {
@mut $Visitor { stopping_on_items: true } as @mut InnerLint
}
}
))
outer_lint_boilerplate_impl!(WhileTrueLintVisitor)
fn lint_while_true() -> @mut OuterLint {
@mut WhileTrueLintVisitor{ stopping_on_items: false } as @mut OuterLint
}
struct TypeLimitsLintVisitor { stopping_on_items: bool }
impl SubitemStoppableVisitor for TypeLimitsLintVisitor {
fn is_running_on_items(&mut self) -> bool { !self.stopping_on_items }
}
impl TypeLimitsLintVisitor {
fn is_valid<T:cmp::Ord>(&mut self, binop: ast::BinOp, v: T,
min: T, max: T) -> bool {
match binop {
ast::BiLt => v <= max,
ast::BiLe => v < max,
ast::BiGt => v >= min,
ast::BiGe => v > min,
ast::BiEq | ast::BiNe => v >= min && v <= max,
_ => fail2!()
}
}
fn rev_binop(&mut self, binop: ast::BinOp) -> ast::BinOp {
match binop {
ast::BiLt => ast::BiGt,
ast::BiLe => ast::BiGe,
ast::BiGt => ast::BiLt,
ast::BiGe => ast::BiLe,
_ => 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(&mut self, int_ty: ast::int_ty) -> (i64, i64) {
match int_ty {
ast::ty_i => (i64::min_value, i64::max_value),
ast::ty_i8 => (i8::min_value as i64, i8::max_value as i64),
ast::ty_i16 => (i16::min_value as i64, i16::max_value as i64),
ast::ty_i32 => (i32::min_value as i64, i32::max_value as i64),
ast::ty_i64 => (i64::min_value, i64::max_value)
}
}
fn uint_ty_range(&mut self, uint_ty: ast::uint_ty) -> (u64, u64) {
match uint_ty {
ast::ty_u => (u64::min_value, u64::max_value),
ast::ty_u8 => (u8::min_value as u64, u8::max_value as u64),
ast::ty_u16 => (u16::min_value as u64, u16::max_value as u64),
ast::ty_u32 => (u32::min_value as u64, u32::max_value as u64),
ast::ty_u64 => (u64::min_value, u64::max_value)
}
}
fn check_limits(&mut self,
cx: &Context,
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 {
self.rev_binop(binop)
} else {
binop
};
match ty::get(ty::expr_ty(cx.tcx, expr)).sty {
ty::ty_int(int_ty) => {
let (min, max) = self.int_ty_range(int_ty);
let lit_val: i64 = match lit.node {
ast::ExprLit(@li) => match li.node {
ast::lit_int(v, _) => v,
ast::lit_uint(v, _) => v as i64,
ast::lit_int_unsuffixed(v) => v,
_ => return true
},
_ => fail2!()
};
self.is_valid(norm_binop, lit_val, min, max)
}
ty::ty_uint(uint_ty) => {
let (min, max): (u64, u64) = self.uint_ty_range(uint_ty);
let lit_val: u64 = match lit.node {
ast::ExprLit(@li) => match li.node {
ast::lit_int(v, _) => v as u64,
ast::lit_uint(v, _) => v,
ast::lit_int_unsuffixed(v) => v as u64,
_ => return true
},
_ => fail2!()
};
self.is_valid(norm_binop, lit_val, min, max)
}
_ => true
}
}
fn is_comparison(&mut self, binop: ast::BinOp) -> bool {
match binop {
ast::BiEq | ast::BiLt | ast::BiLe |
ast::BiNe | ast::BiGe | ast::BiGt => true,
_ => false
}
}
}
impl Visitor<@mut Context> for TypeLimitsLintVisitor {
fn visit_item(&mut self, i:@ast::item, e:@mut Context) {
self.OVERRIDE_visit_item(i, e);
}
fn visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.OVERRIDE_visit_fn(fk, fd, b, s, n, e);
}
fn visit_expr(&mut self, e:@ast::Expr, cx:@mut Context) {
match e.node {
ast::ExprBinary(_, ref binop, l, r) => {
if self.is_comparison(*binop)
&& !self.check_limits(cx, *binop, l, r) {
cx.span_lint(type_limits, e.span,
"comparison is useless due to type limits");
}
}
_ => ()
}
visit::walk_expr(self, e, cx);
}
}
outer_lint_boilerplate_impl!(TypeLimitsLintVisitor)
fn lint_type_limits() -> @mut OuterLint {
@mut TypeLimitsLintVisitor{ stopping_on_items: false } as @mut OuterLint
}
fn check_item_ctypes(cx: &Context, it: &ast::item) {
fn check_ty(cx: &Context, ty: &ast::Ty) {
match ty.node {
ast::ty_path(_, _, id) => {
match cx.tcx.def_map.get_copy(&id) {
ast::DefPrimTy(ast::ty_int(ast::ty_i)) => {
cx.span_lint(ctypes, ty.span,
"found rust type `int` in foreign module, while \
libc::c_int or libc::c_long should be used");
}
ast::DefPrimTy(ast::ty_uint(ast::ty_u)) => {
cx.span_lint(ctypes, ty.span,
"found rust type `uint` in foreign module, while \
libc::c_uint or libc::c_ulong should be used");
}
_ => ()
}
}
ast::ty_ptr(ref mt) => { check_ty(cx, mt.ty) }
_ => ()
}
}
fn check_foreign_fn(cx: &Context, decl: &ast::fn_decl) {
for input in decl.inputs.iter() {
check_ty(cx, &input.ty);
}
check_ty(cx, &decl.output)
}
match it.node {
ast::item_foreign_mod(ref nmod) if !nmod.abis.is_intrinsic() => {
for ni in nmod.items.iter() {
match ni.node {
ast::foreign_item_fn(ref decl, _) => {
check_foreign_fn(cx, decl);
}
ast::foreign_item_static(ref t, _) => { check_ty(cx, t); }
}
}
}
_ => {/* nothing to do */ }
}
}
fn check_type_for_lint(cx: &Context, lint: lint, span: Span, ty: ty::t) {
if cx.get_level(lint) == allow { return }
let mut n_box = 0;
let mut n_uniq = 0;
ty::fold_ty(cx.tcx, ty, |t| {
match ty::get(t).sty {
ty::ty_box(_) => n_box += 1,
ty::ty_uniq(_) => n_uniq += 1,
_ => ()
};
t
});
if n_uniq > 0 && lint != managed_heap_memory {
let s = ty_to_str(cx.tcx, ty);
let m = ~"type uses owned (~ type) pointers: " + s;
cx.span_lint(lint, span, m);
}
if n_box > 0 && lint != owned_heap_memory {
let s = ty_to_str(cx.tcx, ty);
let m = ~"type uses managed (@ type) pointers: " + s;
cx.span_lint(lint, span, m);
}
}
fn check_type(cx: &Context, span: Span, ty: ty::t) {
let xs = [managed_heap_memory, owned_heap_memory, heap_memory];
for lint in xs.iter() {
check_type_for_lint(cx, *lint, span, ty);
}
}
fn check_item_heap(cx: &Context, it: &ast::item) {
match it.node {
ast::item_fn(*) |
ast::item_ty(*) |
ast::item_enum(*) |
ast::item_struct(*) => check_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::item_struct(struct_def, _) => {
for struct_field in struct_def.fields.iter() {
check_type(cx, struct_field.span,
ty::node_id_to_type(cx.tcx,
struct_field.node.id));
}
}
_ => ()
}
}
struct HeapLintVisitor { stopping_on_items: bool }
impl SubitemStoppableVisitor for HeapLintVisitor {
fn is_running_on_items(&mut self) -> bool { !self.stopping_on_items }
}
impl Visitor<@mut Context> for HeapLintVisitor {
fn visit_item(&mut self, i:@ast::item, e:@mut Context) {
self.OVERRIDE_visit_item(i, e);
}
fn visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.OVERRIDE_visit_fn(fk, fd, b, s, n, e);
}
fn visit_expr(&mut self, e:@ast::Expr, cx:@mut Context) {
let ty = ty::expr_ty(cx.tcx, e);
check_type(cx, e.span, ty);
visit::walk_expr(self, e, cx);
}
}
outer_lint_boilerplate_impl!(HeapLintVisitor)
fn lint_heap() -> @mut OuterLint {
@mut HeapLintVisitor { stopping_on_items: false } as @mut OuterLint
}
struct PathStatementLintVisitor {
stopping_on_items: bool
}
impl SubitemStoppableVisitor for PathStatementLintVisitor {
fn is_running_on_items(&mut self) -> bool { !self.stopping_on_items }
}
impl Visitor<@mut Context> for PathStatementLintVisitor {
fn visit_item(&mut self, i:@ast::item, e:@mut Context) {
self.OVERRIDE_visit_item(i, e);
}
fn visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.OVERRIDE_visit_fn(fk, fd, b, s, n, e);
}
fn visit_stmt(&mut self, s:@ast::Stmt, cx:@mut Context) {
match s.node {
ast::StmtSemi(
@ast::Expr { node: ast::ExprPath(_), _ },
_
) => {
cx.span_lint(path_statement, s.span,
"path statement with no effect");
}
_ => ()
}
visit::walk_stmt(self, s, cx);
}
}
outer_lint_boilerplate_impl!(PathStatementLintVisitor)
fn lint_path_statement() -> @mut OuterLint {
@mut PathStatementLintVisitor{ stopping_on_items: false } as @mut OuterLint
}
fn check_item_non_camel_case_types(cx: &Context, it: &ast::item) {
fn is_camel_case(cx: ty::ctxt, ident: ast::Ident) -> bool {
let ident = cx.sess.str_of(ident);
assert!(!ident.is_empty());
let ident = ident.trim_chars(&'_');
// start with a non-lowercase letter rather than non-uppercase
// ones (some scripts don't have a concept of upper/lowercase)
!ident.char_at(0).is_lowercase() &&
!ident.contains_char('_')
}
fn check_case(cx: &Context, sort: &str, ident: ast::Ident, span: Span) {
if !is_camel_case(cx.tcx, ident) {
cx.span_lint(
non_camel_case_types, span,
format!("{} `{}` should have a camel case identifier",
sort, cx.tcx.sess.str_of(ident)));
}
}
match it.node {
ast::item_ty(*) | ast::item_struct(*) => {
check_case(cx, "type", it.ident, it.span)
}
ast::item_trait(*) => {
check_case(cx, "trait", it.ident, it.span)
}
ast::item_enum(ref enum_definition, _) => {
check_case(cx, "type", it.ident, it.span);
for variant in enum_definition.variants.iter() {
check_case(cx, "variant", variant.node.name, variant.span);
}
}
_ => ()
}
}
fn check_item_non_uppercase_statics(cx: &Context, it: &ast::item) {
match it.node {
// only check static constants
ast::item_static(_, ast::MutImmutable, _) => {
let s = cx.tcx.sess.str_of(it.ident);
// check for lowercase letters rather than non-uppercase
// ones (some scripts don't have a concept of
// upper/lowercase)
if s.iter().any(|c| c.is_lowercase()) {
cx.span_lint(non_uppercase_statics, it.span,
"static constant should have an uppercase identifier");
}
}
_ => {}
}
}
fn check_pat_non_uppercase_statics(cx: &Context, p: &ast::Pat) {
// Lint for constants that look like binding identifiers (#7526)
match (&p.node, cx.tcx.def_map.find(&p.id)) {
(&ast::PatIdent(_, ref path, _), Some(&ast::DefStatic(_, false))) => {
// last identifier alone is right choice for this lint.
let ident = path.segments.last().identifier;
let s = cx.tcx.sess.str_of(ident);
if s.iter().any(|c| c.is_lowercase()) {
cx.span_lint(non_uppercase_pattern_statics, path.span,
"static constant in pattern should be all caps");
}
}
_ => {}
}
}
struct UnusedUnsafeLintVisitor { stopping_on_items: bool }
impl SubitemStoppableVisitor for UnusedUnsafeLintVisitor {
fn is_running_on_items(&mut self) -> bool { !self.stopping_on_items }
}
impl Visitor<@mut Context> for UnusedUnsafeLintVisitor {
fn visit_item(&mut self, i:@ast::item, e:@mut Context) {
self.OVERRIDE_visit_item(i, e);
}
fn visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.OVERRIDE_visit_fn(fk, fd, b, s, n, e);
}
fn visit_expr(&mut self, e:@ast::Expr, cx:@mut Context) {
match e.node {
// Don't warn about generated blocks, that'll just pollute the
// output.
ast::ExprBlock(ref blk) => {
if blk.rules == ast::UnsafeBlock(ast::UserProvided) &&
!cx.tcx.used_unsafe.contains(&blk.id) {
cx.span_lint(unused_unsafe, blk.span,
"unnecessary `unsafe` block");
}
}
_ => ()
}
visit::walk_expr(self, e, cx);
}
}
outer_lint_boilerplate_impl!(UnusedUnsafeLintVisitor)
fn lint_unused_unsafe() -> @mut OuterLint {
@mut UnusedUnsafeLintVisitor{ stopping_on_items: false } as @mut OuterLint
}
struct UnusedMutLintVisitor { stopping_on_items: bool }
impl UnusedMutLintVisitor {
fn check_pat(&mut self, cx: &Context, p: @ast::Pat) {
let mut used = false;
let mut bindings = 0;
do pat_util::pat_bindings(cx.tcx.def_map, p) |_, id, _, _| {
used = used || cx.tcx.used_mut_nodes.contains(&id);
bindings += 1;
}
if !used {
let msg = if bindings == 1 {
"variable does not need to be mutable"
} else {
"variables do not need to be mutable"
};
cx.span_lint(unused_mut, p.span, msg);
}
}
fn visit_fn_decl(&mut self, cx: &Context, fd: &ast::fn_decl) {
for arg in fd.inputs.iter() {
if arg.is_mutbl {
self.check_pat(cx, arg.pat);
}
}
}
}
impl SubitemStoppableVisitor for UnusedMutLintVisitor {
fn is_running_on_items(&mut self) -> bool { !self.stopping_on_items }
fn visit_fn_action(&mut self, _a:&visit::fn_kind, fd:&ast::fn_decl,
_b:&ast::Block, _c:Span, _d:ast::NodeId, cx:@mut Context) {
self.visit_fn_decl(cx, fd);
}
}
impl Visitor<@mut Context> for UnusedMutLintVisitor {
fn visit_item(&mut self, i:@ast::item, e:@mut Context) {
self.OVERRIDE_visit_item(i, e);
}
fn visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.OVERRIDE_visit_fn(fk, fd, b, s, n, e);
}
fn visit_local(&mut self, l:@ast::Local, cx:@mut Context) {
if l.is_mutbl {
self.check_pat(cx, l.pat);
}
visit::walk_local(self, l, cx);
}
fn visit_ty_method(&mut self, tm:&ast::TypeMethod, cx:@mut Context) {
self.visit_fn_decl(cx, &tm.decl);
visit::walk_ty_method(self, tm, cx);
}
fn visit_trait_method(&mut self, tm:&ast::trait_method, cx:@mut Context) {
match *tm {
ast::required(ref tm) => self.visit_fn_decl(cx, &tm.decl),
ast::provided(m) => self.visit_fn_decl(cx, &m.decl)
}
visit::walk_trait_method(self, tm, cx);
}
}
outer_lint_boilerplate_impl!(UnusedMutLintVisitor)
fn lint_unused_mut() -> @mut OuterLint {
@mut UnusedMutLintVisitor{ stopping_on_items: false } as @mut OuterLint
}
struct LintReportingIdVisitor {
cx: @mut Context,
}
impl ast_util::IdVisitingOperation for LintReportingIdVisitor {
fn visit_id(&self, id: ast::NodeId) {
match self.cx.tcx.sess.lints.pop(&id) {
None => {}
Some(l) => {
for (lint, span, msg) in l.move_iter() {
self.cx.span_lint(lint, span, msg)
}
}
}
}
}
fn lint_session(cx: @mut Context) -> @mut visit::Visitor<()> {
ast_util::id_visitor(@LintReportingIdVisitor {
cx: cx,
} as @ast_util::IdVisitingOperation, false)
}
struct UnnecessaryAllocationLintVisitor { stopping_on_items: bool }
impl SubitemStoppableVisitor for UnnecessaryAllocationLintVisitor {
fn is_running_on_items(&mut self) -> bool { !self.stopping_on_items }
}
impl Visitor<@mut Context> for UnnecessaryAllocationLintVisitor {
fn visit_item(&mut self, i:@ast::item, e:@mut Context) {
self.OVERRIDE_visit_item(i, e);
}
fn visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.OVERRIDE_visit_fn(fk, fd, b, s, n, e);
}
fn visit_expr(&mut self, e:@ast::Expr, cx:@mut Context) {
self.check(cx, e);
visit::walk_expr(self, e, cx);
}
}
impl UnnecessaryAllocationLintVisitor {
// Warn if string and vector literals with sigils are immediately borrowed.
// Those can have the sigil removed.
fn check(&mut self, cx: &Context, e: &ast::Expr) {
match e.node {
ast::ExprVstore(e2, ast::ExprVstoreUniq) |
ast::ExprVstore(e2, ast::ExprVstoreBox) => {
match e2.node {
ast::ExprLit(@codemap::Spanned{
node: ast::lit_str(*), _}) |
ast::ExprVec(*) => {}
_ => return
}
}
_ => return
}
match cx.tcx.adjustments.find_copy(&e.id) {
Some(@ty::AutoDerefRef(ty::AutoDerefRef {
autoref: Some(ty::AutoBorrowVec(*)), _ })) => {
cx.span_lint(unnecessary_allocation,
e.span, "unnecessary allocation, the sigil can be \
removed");
}
_ => ()
}
}
}
outer_lint_boilerplate_impl!(UnnecessaryAllocationLintVisitor)
fn lint_unnecessary_allocations() -> @mut OuterLint {
@mut UnnecessaryAllocationLintVisitor{ stopping_on_items: false } as @mut OuterLint
}
struct MissingDocLintVisitor { stopping_on_items: bool }
impl MissingDocLintVisitor {
fn check_attrs(&mut self,
cx: @mut Context,
attrs: &[ast::Attribute],
sp: Span,
msg: &str) {
// If we're building a test harness, then warning about documentation is
// probably not really relevant right now
if cx.tcx.sess.opts.test { return }
// If we have doc(hidden), nothing to do
if cx.doc_hidden { return }
// If we're documented, nothing to do
if attrs.iter().any(|a| a.node.is_sugared_doc) { return }
// otherwise, warn!
cx.span_lint(missing_doc, sp, msg);
}
fn check_struct(&mut self, cx: @mut Context, sdef: @ast::struct_def) {
for field in sdef.fields.iter() {
match field.node.kind {
ast::named_field(_, vis) if vis != ast::private => {
self.check_attrs(cx, field.node.attrs, field.span,
"missing documentation for a field");
}
ast::unnamed_field | ast::named_field(*) => {}
}
}
}
}
impl Visitor<@mut Context> for MissingDocLintVisitor {
fn visit_item(&mut self, i:@ast::item, e:@mut Context) {
self.OVERRIDE_visit_item(i, e);
}
fn visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.OVERRIDE_visit_fn(fk, fd, b, s, n, e);
}
fn visit_ty_method(&mut self, m:&ast::TypeMethod, cx:@mut Context) {
// All ty_method objects are linted about because they're part of a
// trait (no visibility)
self.check_attrs(cx, m.attrs, m.span,
"missing documentation for a method");
visit::walk_ty_method(self, m, cx);
}
}
impl SubitemStoppableVisitor for MissingDocLintVisitor {
fn is_running_on_items(&mut self) -> bool { !self.stopping_on_items }
fn visit_fn_action(&mut self, fk:&visit::fn_kind, _d:&ast::fn_decl,
_b:&ast::Block, sp:Span, _id:ast::NodeId, cx:@mut Context) {
// Only warn about explicitly public methods. Soon implicit
// public-ness will hopefully be going away.
match *fk {
visit::fk_method(_, _, m) if m.vis == ast::public => {
// If we're in a trait implementation, no need to duplicate
// documentation
if !cx.in_trait_impl {
self.check_attrs(cx, m.attrs, sp,
"missing documentation for a method");
}
}
_ => {}
}
}
fn visit_item_action(&mut self, it:@ast::item, cx:@mut Context) {
if it.vis != ast::public {
return;
}
match it.node {
// Go ahead and match the fields here instead of using
// visit_struct_field while we have access to the enclosing
// struct's visibility
ast::item_struct(sdef, _) => {
self.check_attrs(cx, it.attrs, it.span,
"missing documentation for a struct");
self.check_struct(cx, sdef);
}
ast::item_trait(*) => {
self.check_attrs(cx, it.attrs, it.span,
"missing documentation for a trait");
}
ast::item_fn(*) => {
self.check_attrs(cx, it.attrs, it.span,
"missing documentation for a function");
}
ast::item_enum(ref edef, _) => {
self.check_attrs(cx, it.attrs, it.span,
"missing documentation for an enum");
for variant in edef.variants.iter() {
if variant.node.vis == ast::private {
continue;
}
self.check_attrs(cx, variant.node.attrs, variant.span,
"missing documentation for a variant");
match variant.node.kind {
ast::struct_variant_kind(sdef) => {
self.check_struct(cx, sdef);
}
_ => ()
}
}
}
_ => {}
}
}
}
outer_lint_boilerplate_impl!(MissingDocLintVisitor)
fn lint_missing_doc() -> @mut OuterLint {
@mut MissingDocLintVisitor { stopping_on_items: false } as @mut OuterLint
}
/// Checks for use of items with #[deprecated], #[experimental] and
/// #[unstable] (or none of them) attributes.
struct StabilityLintVisitor { stopping_on_items: bool }
impl StabilityLintVisitor {
fn handle_def(&mut self, sp: Span, def: &ast::Def, cx: @mut Context) {
let id = ast_util::def_id_of_def(*def);
let stability = if ast_util::is_local(id) {
// this crate
match cx.tcx.items.find(&id.node) {
Some(ast_node) => {
let s = do ast_node.with_attrs |attrs| {
do attrs.map_move |a| {
attr::find_stability(a.iter().map(|a| a.meta()))
}
};
match s {
Some(s) => s,
// no possibility of having attributes
// (e.g. it's a local variable), so just
// ignore it.
None => return
}
}
_ => cx.tcx.sess.bug(format!("handle_def: {:?} not found", id))
}
} else {
// cross-crate
let mut s = None;
// run through all the attributes and take the first
// stability one.
do csearch::get_item_attrs(cx.tcx.cstore, id) |meta_items| {
if s.is_none() {
s = attr::find_stability(meta_items.move_iter())
}
}
s
};
let (lint, label) = match stability {
// no stability attributes == Unstable
None => (unstable, "unmarked"),
Some(attr::Stability { level: attr::Unstable, _ }) => (unstable, "unstable"),
Some(attr::Stability { level: attr::Experimental, _ }) => {
(experimental, "experimental")
}
Some(attr::Stability { level: attr::Deprecated, _ }) => (deprecated, "deprecated"),
_ => return
};
let msg = match stability {
Some(attr::Stability { text: Some(ref s), _ }) => {
format!("use of {} item: {}", label, *s)
}
_ => format!("use of {} item", label)
};
cx.span_lint(lint, sp, msg);
}
}
impl SubitemStoppableVisitor for StabilityLintVisitor {
fn is_running_on_items(&mut self) -> bool { !self.stopping_on_items }
}
impl Visitor<@mut Context> for StabilityLintVisitor {
fn visit_item(&mut self, i:@ast::item, e:@mut Context) {
self.OVERRIDE_visit_item(i, e);
}
fn visit_fn(&mut self, fk:&visit::fn_kind, fd:&ast::fn_decl,
b:&ast::Block, s:Span, n:ast::NodeId, e:@mut Context) {
self.OVERRIDE_visit_fn(fk, fd, b, s, n, e);
}
fn visit_expr(&mut self, ex: @ast::Expr, cx: @mut Context) {
match ex.node {
ast::ExprMethodCall(*) |
ast::ExprPath(*) |
ast::ExprStruct(*) => {
match cx.tcx.def_map.find(&ex.id) {
Some(def) => self.handle_def(ex.span, def, cx),
None => {}
}
}
_ => {}
}
visit::walk_expr(self, ex, cx)
}
}
outer_lint_boilerplate_impl!(StabilityLintVisitor)
fn lint_stability() -> @mut OuterLint {
@mut StabilityLintVisitor { stopping_on_items: false } as @mut OuterLint
}
struct LintCheckVisitor;
impl Visitor<@mut Context> for LintCheckVisitor {
fn visit_pat(&mut self, p:@ast::Pat, cx: @mut Context) {
check_pat_non_uppercase_statics(cx, p);
visit::walk_pat(self, p, cx);
}
fn visit_item(&mut self, it:@ast::item, cx: @mut Context) {
do cx.with_lint_attrs(it.attrs) {
match it.node {
ast::item_impl(_, Some(*), _, _) => {
cx.in_trait_impl = true;
}
_ => {}
}
check_item_ctypes(cx, it);
check_item_non_camel_case_types(cx, it);
check_item_non_uppercase_statics(cx, it);
check_item_heap(cx, it);
cx.process(Item(it));
visit::walk_item(self, it, cx);
cx.in_trait_impl = false;
}
}
fn visit_fn(&mut self, fk:&visit::fn_kind, decl:&ast::fn_decl,
body:&ast::Block, span:Span, id:ast::NodeId, cx:@mut Context) {
match *fk {
visit::fk_method(_, _, m) => {
do cx.with_lint_attrs(m.attrs) {
cx.process(Method(m));
visit::walk_fn(self,
fk,
decl,
body,
span,
id,
cx);
}
}
_ => {
visit::walk_fn(self,
fk,
decl,
body,
span,
id,
cx);
}
}
}
}
pub fn check_crate(tcx: ty::ctxt, crate: &ast::Crate) {
let cx = @mut Context {
dict: @get_lint_dict(),
curr: SmallIntMap::new(),
tcx: tcx,
lint_stack: ~[],
visitors: ~[],
in_trait_impl: false,
doc_hidden: false,
};
// Install defaults.
for (_, spec) in cx.dict.iter() {
cx.set_level(spec.lint, spec.default, Default);
}
// Install command-line options, overriding defaults.
for &(lint, level) in tcx.sess.opts.lint_opts.iter() {
cx.set_level(lint, level, CommandLine);
}
// Register each of the lint passes with the context
cx.add_old_lint(lint_while_true());
cx.add_old_lint(lint_path_statement());
cx.add_old_lint(lint_heap());
cx.add_old_lint(lint_type_limits());
cx.add_old_lint(lint_unused_unsafe());
cx.add_old_lint(lint_unused_mut());
cx.add_old_lint(lint_unnecessary_allocations());
cx.add_old_lint(lint_missing_doc());
cx.add_old_lint(lint_stability());
cx.add_lint(lint_session(cx));
// Actually perform the lint checks (iterating the ast)
do cx.with_lint_attrs(crate.attrs) {
cx.process(Crate(crate));
let mut visitor = LintCheckVisitor;
visit::walk_crate(&mut visitor, crate, cx);
}
// If we missed any lints added to the session, then there's a bug somewhere
// in the iteration code.
for (id, v) in tcx.sess.lints.iter() {
for t in v.iter() {
match *t {
(lint, span, ref msg) =>
tcx.sess.span_bug(span, format!("unprocessed lint {:?} at {}: \
{}",
lint,
ast_map::node_id_to_str(
tcx.items,
*id,
token::get_ident_interner()),
*msg))
}
}
}
tcx.sess.abort_if_errors();
}