rust/src/librustc/middle/lint.rs

1057 lines
34 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 core::prelude::*;
use driver::session::Session;
use driver::session;
use middle::ty;
use util::ppaux::{ty_to_str};
use core::char;
use core::cmp;
use core::either;
use core::i8;
use core::i16;
use core::i32;
use core::i64;
use core::int;
use core::str;
use core::u8;
use core::u16;
use core::u32;
use core::u64;
use core::uint;
use core::vec;
use std::oldmap::{Map, HashMap};
use std::oldmap;
use std::smallintmap::SmallIntMap;
use syntax::attr;
use syntax::codemap::span;
use syntax::codemap;
use syntax::print::pprust::{expr_to_str, mode_to_str, pat_to_str};
use syntax::{ast, ast_util, visit};
/**
* 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.
*
* We also build up a table containing information about lint settings, in
* order to allow other passes to take advantage of the lint attribute
* infrastructure. To save space, the table is keyed by the id of /items/, not
* of every expression. When an item has the default settings, the entry will
* be omitted. If we start allowing lint attributes on expressions, we will
* start having entries for expressions that do not share their enclosing
* items settings.
*
* This module then, exports two passes: one that populates the lint
* settings table in the session and is run early in the compile process, and
* one that does a variety of lint checks, and is run late in the compile
* process.
*/
#[deriving_eq]
pub enum lint {
ctypes,
unused_imports,
while_true,
path_statement,
implicit_copies,
unrecognized_lint,
non_implicitly_copyable_typarams,
vecs_implicitly_copyable,
deprecated_mode,
deprecated_pattern,
non_camel_case_types,
type_limits,
default_methods,
deprecated_self,
deprecated_mutable_fields,
managed_heap_memory,
owned_heap_memory,
heap_memory,
legacy_modes,
// FIXME(#3266)--make liveness warnings lintable
// unused_variable,
// dead_assignment
}
pub fn level_to_str(lv: level) -> &static/str {
match lv {
allow => "allow",
warn => "warn",
deny => "deny",
forbid => "forbid"
}
}
#[deriving_eq]
pub enum level {
allow, warn, deny, forbid
}
struct LintSpec {
lint: lint,
desc: &static/str,
default: level
}
pub type LintDict = HashMap<@~str, @LintSpec>;
/*
Pass names should not contain a '-', as the compiler normalizes
'-' to '_' in command-line flags
*/
pub fn get_lint_dict() -> LintDict {
let v = ~[
(@~"ctypes",
@LintSpec {
lint: ctypes,
desc: "proper use of core::libc types in foreign modules",
default: warn
}),
(@~"unused_imports",
@LintSpec {
lint: unused_imports,
desc: "imports that are never used",
default: warn
}),
(@~"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_implicitly_copyable_typarams",
@LintSpec {
lint: non_implicitly_copyable_typarams,
desc: "passing non implicitly copyable types as copy type params",
default: warn
}),
(@~"vecs_implicitly_copyable",
@LintSpec {
lint: vecs_implicitly_copyable,
desc: "make vecs and strs not implicitly copyable \
(only checked at top level)",
default: warn
}),
(@~"implicit_copies",
@LintSpec {
lint: implicit_copies,
desc: "implicit copies of non implicitly copyable data",
default: warn
}),
(@~"deprecated_mode",
@LintSpec {
lint: deprecated_mode,
desc: "warn about deprecated uses of modes",
default: warn
}),
(@~"deprecated_pattern",
@LintSpec {
lint: deprecated_pattern,
desc: "warn about deprecated uses of pattern bindings",
default: allow
}),
(@~"non_camel_case_types",
@LintSpec {
lint: non_camel_case_types,
desc: "types, variants and traits should have camel case names",
default: allow
}),
(@~"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
}),
(@~"legacy modes",
@LintSpec {
lint: legacy_modes,
desc: "allow legacy modes",
default: forbid
}),
(@~"type_limits",
@LintSpec {
lint: type_limits,
desc: "comparisons made useless by limits of the types involved",
default: warn
}),
(@~"default_methods",
@LintSpec {
lint: default_methods,
desc: "allow default methods",
default: deny
}),
(@~"deprecated_self",
@LintSpec {
lint: deprecated_self,
desc: "warn about deprecated uses of `self`",
default: warn
}),
(@~"deprecated_mutable_fields",
@LintSpec {
lint: deprecated_mutable_fields,
desc: "deprecated mutable fields in structures",
default: deny
}),
/* FIXME(#3266)--make liveness warnings lintable
(@~"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
}),
*/
];
oldmap::hash_from_vec(v)
}
// This is a highly not-optimal set of data structure decisions.
type LintModes = @mut SmallIntMap<level>;
type LintModeMap = HashMap<ast::node_id, LintModes>;
// settings_map maps node ids of items with non-default lint settings
// to their settings; default_settings contains the settings for everything
// not in the map.
pub struct LintSettings {
default_settings: LintModes,
settings_map: LintModeMap
}
pub fn mk_lint_settings() -> LintSettings {
LintSettings {
default_settings: @mut SmallIntMap::new(),
settings_map: HashMap()
}
}
pub fn get_lint_level(modes: LintModes, lint: lint) -> level {
match modes.find(&(lint as uint)) {
Some(&c) => c,
None => allow
}
}
pub fn get_lint_settings_level(settings: LintSettings,
lint_mode: lint,
_expr_id: ast::node_id,
item_id: ast::node_id)
-> level {
match settings.settings_map.find(&item_id) {
Some(modes) => get_lint_level(modes, lint_mode),
None => get_lint_level(settings.default_settings, lint_mode)
}
}
// This is kind of unfortunate. It should be somewhere else, or we should use
// a persistent data structure...
fn clone_lint_modes(modes: LintModes) -> LintModes {
@mut (copy *modes)
}
struct Context {
dict: LintDict,
curr: LintModes,
is_default: bool,
sess: Session
}
pub impl Context {
fn get_level(&self, lint: lint) -> level {
get_lint_level(self.curr, lint)
}
fn set_level(&self, lint: lint, level: level) {
if level == allow {
self.curr.remove(&(lint as uint));
} else {
self.curr.insert(lint as uint, level);
}
}
fn span_lint(&self, level: level, span: span, +msg: ~str) {
self.sess.span_lint_level(level, span, msg);
}
/**
* 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(&self, attrs: ~[ast::attribute], f: fn(Context)) {
let mut new_ctxt = *self;
let mut triples = ~[];
for [allow, warn, deny, forbid].each |level| {
let level_name = level_to_str(*level);
let metas =
attr::attr_metas(attr::find_attrs_by_name(attrs, level_name));
for metas.each |meta| {
match /*bad*/copy meta.node {
ast::meta_list(_, metas) => {
for metas.each |meta| {
match meta.node {
ast::meta_word(ref lintname) => {
triples.push((*meta,
*level,
/*bad*/copy *lintname));
}
_ => {
self.sess.span_err(
meta.span,
~"malformed lint attribute");
}
}
}
}
_ => {
self.sess.span_err(meta.span,
~"malformed lint attribute");
}
}
}
}
for triples.each |triple| {
// FIXME(#3874): it would be nicer to write this...
// let (meta, level, lintname) = /*bad*/copy *pair;
let (meta, level, lintname) = match *triple {
(ref meta, level, lintname) => (meta, level, lintname)
};
match self.dict.find(&lintname) {
None => {
self.span_lint(
new_ctxt.get_level(unrecognized_lint),
meta.span,
fmt!("unknown `%s` attribute: `%s`",
level_to_str(level), *lintname));
}
Some(lint) => {
if new_ctxt.get_level(lint.lint) == forbid &&
level != forbid {
self.span_lint(
forbid,
meta.span,
fmt!("%s(%s) overruled by outer forbid(%s)",
level_to_str(level),
*lintname, *lintname));
}
// we do multiple unneeded copies of the
// map if many attributes are set, but
// this shouldn't actually be a problem...
let c = clone_lint_modes(new_ctxt.curr);
new_ctxt = Context {
is_default: false,
curr: c,
.. new_ctxt
};
new_ctxt.set_level(lint.lint, level);
}
}
}
f(new_ctxt);
}
}
fn build_settings_item(i: @ast::item, &&cx: Context, v: visit::vt<Context>) {
do cx.with_lint_attrs(/*bad*/copy i.attrs) |cx| {
if !cx.is_default {
cx.sess.lint_settings.settings_map.insert(i.id, cx.curr);
}
visit::visit_item(i, cx, v);
}
}
pub fn build_settings_crate(sess: session::Session, crate: @ast::crate) {
let cx = Context {
dict: get_lint_dict(),
curr: @mut SmallIntMap::new(),
is_default: true,
sess: sess
};
// Install defaults.
for cx.dict.each_value |&spec| {
cx.set_level(spec.lint, spec.default);
}
// Install command-line options, overriding defaults.
for sess.opts.lint_opts.each |pair| {
let (lint,level) = *pair;
cx.set_level(lint, level);
}
do cx.with_lint_attrs(/*bad*/copy crate.node.attrs) |cx| {
// Copy out the default settings
for cx.curr.each |&(k, &v)| {
sess.lint_settings.default_settings.insert(k, v);
}
let cx = Context {
is_default: true,
.. cx
};
let visit = visit::mk_vt(@visit::Visitor {
visit_item: build_settings_item,
.. *visit::default_visitor()
});
visit::visit_crate(*crate, cx, visit);
}
sess.abort_if_errors();
}
fn check_item(i: @ast::item, cx: ty::ctxt) {
check_item_ctypes(cx, i);
check_item_while_true(cx, i);
check_item_path_statement(cx, i);
check_item_non_camel_case_types(cx, i);
check_item_heap(cx, i);
check_item_deprecated_modes(cx, i);
check_item_type_limits(cx, i);
check_item_default_methods(cx, i);
check_item_deprecated_self(cx, i);
check_item_deprecated_mutable_fields(cx, i);
}
// Take a visitor, and modify it so that it will not proceed past subitems.
// This is used to make the simple visitors used for the lint passes
// not traverse into subitems, since that is handled by the outer
// lint visitor.
fn item_stopping_visitor<E>(v: visit::vt<E>) -> visit::vt<E> {
visit::mk_vt(@visit::Visitor {visit_item: |_i, _e, _v| { },.. **v})
}
fn check_item_while_true(cx: ty::ctxt, it: @ast::item) {
let visit = item_stopping_visitor(
visit::mk_simple_visitor(@visit::SimpleVisitor {
visit_expr: |e: @ast::expr| {
match e.node {
ast::expr_while(cond, _) => {
match cond.node {
ast::expr_lit(@codemap::spanned {
node: ast::lit_bool(true), _}) =>
{
cx.sess.span_lint(
while_true, e.id, it.id,
e.span,
~"denote infinite loops \
with loop { ... }");
}
_ => ()
}
}
_ => ()
}
},
.. *visit::default_simple_visitor()
}));
visit::visit_item(it, (), visit);
}
fn check_item_type_limits(cx: ty::ctxt, it: @ast::item) {
pure fn is_valid<T:cmp::Ord>(binop: ast::binop, v: T,
min: T, max: T) -> bool {
match binop {
ast::lt => v <= max,
ast::le => v < max,
ast::gt => v >= min,
ast::ge => v > min,
ast::eq | ast::ne => v >= min && v <= max,
_ => fail!()
}
}
pure fn rev_binop(binop: ast::binop) -> ast::binop {
match binop {
ast::lt => ast::gt,
ast::le => ast::ge,
ast::gt => ast::lt,
ast::ge => ast::le,
_ => binop
}
}
pure fn int_ty_range(int_ty: ast::int_ty) -> (i64, i64) {
match int_ty {
ast::ty_i => (int::min_value as i64, int::max_value as i64),
ast::ty_char => (u32::min_value as i64, u32::max_value as i64),
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)
}
}
pure fn uint_ty_range(uint_ty: ast::uint_ty) -> (u64, u64) {
match uint_ty {
ast::ty_u => (uint::min_value as u64, uint::max_value as u64),
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(cx: ty::ctxt, binop: ast::binop, l: &ast::expr,
r: &ast::expr) -> bool {
let (lit, expr, swap) = match (&l.node, &r.node) {
(&ast::expr_lit(_), _) => (l, r, true),
(_, &ast::expr_lit(_)) => (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::get(ty::expr_ty(cx, @/*bad*/copy *expr)).sty {
ty::ty_int(int_ty) => {
let (min, max) = int_ty_range(int_ty);
let lit_val: i64 = match lit.node {
ast::expr_lit(@li) => match li.node {
ast::lit_int(v, _) => v,
ast::lit_uint(v, _) => v as i64,
ast::lit_int_unsuffixed(v) => v,
_ => return true
},
_ => fail!()
};
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::expr_lit(@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
},
_ => fail!()
};
is_valid(norm_binop, lit_val, min, max)
}
_ => true
}
}
pure fn is_comparison(binop: ast::binop) -> bool {
match binop {
ast::eq | ast::lt | ast::le |
ast::ne | ast::ge | ast::gt => true,
_ => false
}
}
let visit_expr: @fn(@ast::expr) = |e| {
match e.node {
ast::expr_binary(ref binop, @ref l, @ref r) => {
if is_comparison(*binop)
&& !check_limits(cx, *binop, l, r) {
cx.sess.span_lint(
type_limits, e.id, it.id, e.span,
~"comparison is useless due to type limits");
}
}
_ => ()
}
};
let visit = item_stopping_visitor(
visit::mk_simple_visitor(@visit::SimpleVisitor {
visit_expr: visit_expr,
.. *visit::default_simple_visitor()
}));
visit::visit_item(it, (), visit);
}
fn check_item_default_methods(cx: ty::ctxt, item: @ast::item) {
match /*bad*/copy item.node {
ast::item_trait(_, _, methods) => {
for methods.each |method| {
match *method {
ast::required(*) => {}
ast::provided(*) => {
cx.sess.span_lint(
default_methods,
item.id,
item.id,
item.span,
~"default methods are experimental");
}
}
}
}
_ => {}
}
}
fn check_item_deprecated_self(cx: ty::ctxt, item: @ast::item) {
fn maybe_warn(cx: ty::ctxt,
item: @ast::item,
self_ty: ast::self_ty) {
match self_ty.node {
ast::sty_by_ref => {
cx.sess.span_lint(
deprecated_self,
item.id,
item.id,
self_ty.span,
~"this method form is deprecated; use an explicit `self` \
parameter or mark the method as static");
}
_ => {}
}
}
match /*bad*/copy item.node {
ast::item_trait(_, _, methods) => {
for methods.each |method| {
match /*bad*/copy *method {
ast::required(ty_method) => {
maybe_warn(cx, item, ty_method.self_ty);
}
ast::provided(method) => {
maybe_warn(cx, item, method.self_ty);
}
}
}
}
ast::item_impl(_, _, _, methods) => {
for methods.each |method| {
maybe_warn(cx, item, method.self_ty);
}
}
_ => {}
}
}
fn check_item_deprecated_mutable_fields(cx: ty::ctxt, item: @ast::item) {
match item.node {
ast::item_struct(struct_def, _) => {
for struct_def.fields.each |field| {
match field.node.kind {
ast::named_field(_, ast::struct_mutable, _) => {
cx.sess.span_lint(deprecated_mutable_fields,
item.id,
item.id,
field.span,
~"mutable fields are deprecated");
}
ast::named_field(*) | ast::unnamed_field => {}
}
}
}
_ => {}
}
}
fn check_item_ctypes(cx: ty::ctxt, it: @ast::item) {
fn check_foreign_fn(cx: ty::ctxt, fn_id: ast::node_id,
decl: &ast::fn_decl) {
let tys = vec::map(decl.inputs, |a| a.ty );
for vec::each(vec::append_one(tys, decl.output)) |ty| {
match ty.node {
ast::ty_path(_, id) => {
match cx.def_map.get(&id) {
ast::def_prim_ty(ast::ty_int(ast::ty_i)) => {
cx.sess.span_lint(
ctypes, id, fn_id,
ty.span,
~"found rust type `int` in foreign module, while \
libc::c_int or libc::c_long should be used");
}
ast::def_prim_ty(ast::ty_uint(ast::ty_u)) => {
cx.sess.span_lint(
ctypes, id, fn_id,
ty.span,
~"found rust type `uint` in foreign module, while \
libc::c_uint or libc::c_ulong should be used");
}
_ => ()
}
}
_ => ()
}
}
}
match it.node {
ast::item_foreign_mod(ref nmod)
if attr::foreign_abi(it.attrs) !=
either::Right(ast::foreign_abi_rust_intrinsic) => {
for nmod.items.each |ni| {
match /*bad*/copy ni.node {
ast::foreign_item_fn(ref decl, _, _) => {
check_foreign_fn(cx, it.id, decl);
}
// FIXME #4622: Not implemented.
ast::foreign_item_const(*) => {}
}
}
}
_ => {/* nothing to do */ }
}
}
fn check_item_heap(cx: ty::ctxt, it: @ast::item) {
fn check_type_for_lint(cx: ty::ctxt, lint: lint,
node: ast::node_id,
item: ast::node_id,
span: span, ty: ty::t) {
if get_lint_settings_level(cx.sess.lint_settings,
lint, node, item) != allow {
let mut n_box = 0;
let mut n_uniq = 0;
ty::fold_ty(cx, 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, ty);
let m = ~"type uses owned (~ type) pointers: " + s;
cx.sess.span_lint(lint, node, item, span, m);
}
if (n_box > 0 && lint != owned_heap_memory) {
let s = ty_to_str(cx, ty);
let m = ~"type uses managed (@ type) pointers: " + s;
cx.sess.span_lint(lint, node, item, span, m);
}
}
}
fn check_type(cx: ty::ctxt,
node: ast::node_id,
item: ast::node_id,
span: span, ty: ty::t) {
for [managed_heap_memory,
owned_heap_memory,
heap_memory].each |lint| {
check_type_for_lint(cx, *lint, node, item, span, ty);
}
}
match it.node {
ast::item_fn(*) |
ast::item_ty(*) |
ast::item_enum(*) |
ast::item_struct(*) |
ast::item_trait(*) => check_type(cx, it.id, it.id, it.span,
ty::node_id_to_type(cx, 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_def.fields.each |struct_field| {
check_type(cx, struct_field.node.id, it.id,
struct_field.span,
ty::node_id_to_type(cx, struct_field.node.id));
}
}
_ => ()
}
let visit = item_stopping_visitor(
visit::mk_simple_visitor(@visit::SimpleVisitor {
visit_expr: |e: @ast::expr| {
let ty = ty::expr_ty(cx, e);
check_type(cx, e.id, it.id, e.span, ty);
},
.. *visit::default_simple_visitor()
}));
visit::visit_item(it, (), visit);
}
fn check_item_path_statement(cx: ty::ctxt, it: @ast::item) {
let visit = item_stopping_visitor(
visit::mk_simple_visitor(@visit::SimpleVisitor {
visit_stmt: |s: @ast::stmt| {
match s.node {
ast::stmt_semi(
@ast::expr { id: id, node: ast::expr_path(_), _ },
_
) => {
cx.sess.span_lint(
path_statement, id, it.id,
s.span,
~"path statement with no effect");
}
_ => ()
}
},
.. *visit::default_simple_visitor()
}));
visit::visit_item(it, (), visit);
}
fn check_item_non_camel_case_types(cx: ty::ctxt, it: @ast::item) {
fn is_camel_case(cx: ty::ctxt, ident: ast::ident) -> bool {
let ident = cx.sess.str_of(ident);
fail_unless!(!ident.is_empty());
let ident = ident_without_trailing_underscores(*ident);
let ident = ident_without_leading_underscores(ident);
char::is_uppercase(str::char_at(ident, 0)) &&
!ident.contains_char('_')
}
fn ident_without_trailing_underscores(ident: &r/str) -> &r/str {
match str::rfind(ident, |c| c != '_') {
Some(idx) => str::view(ident, 0, idx + 1),
None => ident, // all underscores
}
}
fn ident_without_leading_underscores(ident: &r/str) -> &r/str {
match str::find(ident, |c| c != '_') {
Some(idx) => str::view(ident, idx, ident.len()),
None => ident // all underscores
}
}
fn check_case(cx: ty::ctxt, ident: ast::ident,
expr_id: ast::node_id, item_id: ast::node_id,
span: span) {
if !is_camel_case(cx, ident) {
cx.sess.span_lint(
non_camel_case_types, expr_id, item_id, span,
~"type, variant, or trait should have \
a camel case identifier");
}
}
match it.node {
ast::item_ty(*) | ast::item_struct(*) |
ast::item_trait(*) => {
check_case(cx, it.ident, it.id, it.id, it.span)
}
ast::item_enum(ref enum_definition, _) => {
check_case(cx, it.ident, it.id, it.id, it.span);
for enum_definition.variants.each |variant| {
check_case(cx, variant.node.name,
variant.node.id, it.id, variant.span);
}
}
_ => ()
}
}
fn check_fn(tcx: ty::ctxt, fk: &visit::fn_kind, decl: &ast::fn_decl,
_body: &ast::blk, span: span, id: ast::node_id) {
debug!("lint check_fn fk=%? id=%?", fk, id);
// don't complain about blocks, since they tend to get their modes
// specified from the outside
match *fk {
visit::fk_fn_block(*) => { return; }
_ => {}
}
let fn_ty = ty::node_id_to_type(tcx, id);
check_fn_deprecated_modes(tcx, fn_ty, decl, span, id);
}
fn check_fn_deprecated_modes(tcx: ty::ctxt, fn_ty: ty::t, decl: &ast::fn_decl,
span: span, id: ast::node_id) {
match ty::get(fn_ty).sty {
ty::ty_closure(ty::ClosureTy {sig: ref sig, _}) |
ty::ty_bare_fn(ty::BareFnTy {sig: ref sig, _}) => {
let mut counter = 0;
for vec::each2(sig.inputs, decl.inputs) |arg_ty, arg_ast| {
counter += 1;
debug!("arg %d, ty=%s, mode=%s",
counter,
ty_to_str(tcx, arg_ty.ty),
mode_to_str(arg_ast.mode));
match arg_ast.mode {
ast::expl(ast::by_copy) => {
if !tcx.legacy_modes {
tcx.sess.span_lint(
deprecated_mode, id, id, span,
fmt!("argument %d uses by-copy mode",
counter));
}
}
ast::expl(_) => {
tcx.sess.span_lint(
deprecated_mode, id, id,
span,
fmt!("argument %d uses an explicit mode", counter));
}
ast::infer(_) => {
if tcx.legacy_modes {
let kind = ty::type_contents(tcx, arg_ty.ty);
if !kind.is_safe_for_default_mode(tcx) {
tcx.sess.span_lint(
deprecated_mode, id, id,
span,
fmt!("argument %d uses the default mode \
but shouldn't",
counter));
}
}
}
}
match ty::get(arg_ty.ty).sty {
ty::ty_closure(*) | ty::ty_bare_fn(*) => {
let span = arg_ast.ty.span;
// Recurse to check fn-type argument
match arg_ast.ty.node {
ast::ty_closure(@ast::TyClosure{decl: ref d, _}) |
ast::ty_bare_fn(@ast::TyBareFn{decl: ref d, _})=>{
check_fn_deprecated_modes(tcx, arg_ty.ty,
d, span, id);
}
ast::ty_path(*) => {
// This is probably a typedef, so we can't
// see the actual fn decl
// e.g. fn foo(f: InitOp<T>)
}
_ => {
tcx.sess.span_warn(span, ~"what");
error!("arg %d, ty=%s, mode=%s",
counter,
ty_to_str(tcx, arg_ty.ty),
mode_to_str(arg_ast.mode));
error!("%?",arg_ast.ty.node);
fail!()
}
};
}
_ => ()
}
}
}
_ => tcx.sess.impossible_case(span, ~"check_fn: function has \
non-fn type")
}
}
fn check_item_deprecated_modes(tcx: ty::ctxt, it: @ast::item) {
match it.node {
ast::item_ty(ty, _) => {
match ty.node {
ast::ty_closure(@ast::TyClosure {decl: ref decl, _}) |
ast::ty_bare_fn(@ast::TyBareFn {decl: ref decl, _}) => {
let fn_ty = ty::node_id_to_type(tcx, it.id);
check_fn_deprecated_modes(
tcx, fn_ty, decl, ty.span, it.id)
}
_ => ()
}
}
_ => ()
}
}
pub fn check_crate(tcx: ty::ctxt, crate: @ast::crate) {
let v = visit::mk_simple_visitor(@visit::SimpleVisitor {
visit_item: |it|
check_item(it, tcx),
visit_fn: |fk, decl, body, span, id|
check_fn(tcx, fk, decl, body, span, id),
.. *visit::default_simple_visitor()
});
visit::visit_crate(*crate, (), v);
tcx.sess.abort_if_errors();
}
//
// Local Variables:
// mode: rust
// fill-column: 78;
// indent-tabs-mode: nil
// c-basic-offset: 4
// buffer-file-coding-system: utf-8-unix
// End:
//