/
lint.rs
1829 lines (1639 loc) · 58.6 KB
/
lint.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.
//! 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.
//!
//! 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 few linting functions and
//! modify the Context visitor appropriately. If you're adding lints from the
//! Context itself, span_lint should be used instead of add_lint.
#[allow(non_camel_case_types)];
use driver::session;
use metadata::csearch;
use middle::dead::DEAD_CODE_LINT_STR;
use middle::pat_util;
use middle::privacy;
use middle::trans::adt; // for `adt::is_ffi_safe`
use middle::ty;
use middle::typeck::astconv::{ast_ty_to_ty, AstConv};
use middle::typeck::infer;
use middle::typeck;
use util::ppaux::{ty_to_str};
use std::cmp;
use collections::HashMap;
use std::i16;
use std::i32;
use std::i64;
use std::i8;
use std::to_str::ToStr;
use std::u16;
use std::u32;
use std::u64;
use std::u8;
use collections::SmallIntMap;
use syntax::ast_map;
use syntax::ast_util::IdVisitingOperation;
use syntax::attr::{AttrMetaMethods, AttributeMethods};
use syntax::attr;
use syntax::codemap::Span;
use syntax::parse::token::InternedString;
use syntax::parse::token;
use syntax::visit::Visitor;
use syntax::{ast, ast_util, visit};
#[deriving(Clone, Eq, Ord, TotalEq, TotalOrd)]
pub enum Lint {
CTypes,
UnusedImports,
UnnecessaryQualification,
WhileTrue,
PathStatement,
UnrecognizedLint,
NonCamelCaseTypes,
NonUppercaseStatics,
NonUppercasePatternStatics,
UppercaseVariables,
UnnecessaryParens,
TypeLimits,
TypeOverflow,
UnusedUnsafe,
UnsafeBlock,
AttributeUsage,
UnknownFeatures,
UnknownCrateType,
ManagedHeapMemory,
OwnedHeapMemory,
HeapMemory,
UnusedVariable,
DeadAssignment,
UnusedMut,
UnnecessaryAllocation,
DeadCode,
VisiblePrivateTypes,
UnnecessaryTypecast,
MissingDoc,
UnreachableCode,
Deprecated,
Experimental,
Unstable,
UnusedMustUse,
UnusedResult,
DeprecatedOwnedVector,
Warnings,
RawPointerDeriving,
}
pub fn level_to_str(lv: level) -> &'static str {
match lv {
allow => "allow",
warn => "warn",
deny => "deny",
forbid => "forbid"
}
}
#[deriving(Clone, Eq, Ord, TotalEq, TotalOrd)]
pub enum level {
allow, warn, deny, forbid
}
#[deriving(Clone, Eq, Ord, TotalEq, TotalOrd)]
pub struct LintSpec {
default: level,
lint: Lint,
desc: &'static str,
}
pub type LintDict = HashMap<&'static str, LintSpec>;
#[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
}),
("unused_imports",
LintSpec {
lint: UnusedImports,
desc: "imports that are never used",
default: warn
}),
("unnecessary_qualification",
LintSpec {
lint: UnnecessaryQualification,
desc: "detects unnecessarily qualified names",
default: allow
}),
("while_true",
LintSpec {
lint: WhileTrue,
desc: "suggest using `loop { }` instead of `while true { }`",
default: warn
}),
("path_statement",
LintSpec {
lint: PathStatement,
desc: "path statements with no effect",
default: warn
}),
("unrecognized_lint",
LintSpec {
lint: UnrecognizedLint,
desc: "unrecognized lint attribute",
default: warn
}),
("non_camel_case_types",
LintSpec {
lint: NonCamelCaseTypes,
desc: "types, variants and traits should have camel case names",
default: warn
}),
("non_uppercase_statics",
LintSpec {
lint: NonUppercaseStatics,
desc: "static constants should have uppercase identifiers",
default: allow
}),
("non_uppercase_pattern_statics",
LintSpec {
lint: NonUppercasePatternStatics,
desc: "static constants in match patterns should be all caps",
default: warn
}),
("uppercase_variables",
LintSpec {
lint: UppercaseVariables,
desc: "variable and structure field names should start with a lowercase character",
default: warn
}),
("unnecessary_parens",
LintSpec {
lint: UnnecessaryParens,
desc: "`if`, `match`, `while` and `return` do not need parentheses",
default: warn
}),
("managed_heap_memory",
LintSpec {
lint: ManagedHeapMemory,
desc: "use of managed (@ type) heap memory",
default: allow
}),
("owned_heap_memory",
LintSpec {
lint: OwnedHeapMemory,
desc: "use of owned (~ type) heap memory",
default: allow
}),
("heap_memory",
LintSpec {
lint: HeapMemory,
desc: "use of any (~ type or @ type) heap memory",
default: allow
}),
("type_limits",
LintSpec {
lint: TypeLimits,
desc: "comparisons made useless by limits of the types involved",
default: warn
}),
("type_overflow",
LintSpec {
lint: TypeOverflow,
desc: "literal out of range for its type",
default: warn
}),
("unused_unsafe",
LintSpec {
lint: UnusedUnsafe,
desc: "unnecessary use of an `unsafe` block",
default: warn
}),
("unsafe_block",
LintSpec {
lint: UnsafeBlock,
desc: "usage of an `unsafe` block",
default: allow
}),
("attribute_usage",
LintSpec {
lint: AttributeUsage,
desc: "detects bad use of attributes",
default: warn
}),
("unused_variable",
LintSpec {
lint: UnusedVariable,
desc: "detect variables which are not used in any way",
default: warn
}),
("dead_assignment",
LintSpec {
lint: DeadAssignment,
desc: "detect assignments that will never be read",
default: warn
}),
("unnecessary_typecast",
LintSpec {
lint: UnnecessaryTypecast,
desc: "detects unnecessary type casts, that can be removed",
default: allow,
}),
("unused_mut",
LintSpec {
lint: UnusedMut,
desc: "detect mut variables which don't need to be mutable",
default: warn
}),
("unnecessary_allocation",
LintSpec {
lint: UnnecessaryAllocation,
desc: "detects unnecessary allocations that can be eliminated",
default: warn
}),
(DEAD_CODE_LINT_STR,
LintSpec {
lint: DeadCode,
desc: "detect piece of code that will never be used",
default: warn
}),
("visible_private_types",
LintSpec {
lint: VisiblePrivateTypes,
desc: "detect use of private types in exported type signatures",
default: warn
}),
("missing_doc",
LintSpec {
lint: MissingDoc,
desc: "detects missing documentation for public members",
default: allow
}),
("unreachable_code",
LintSpec {
lint: UnreachableCode,
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
}),
("unknown_features",
LintSpec {
lint: UnknownFeatures,
desc: "unknown features found in crate-level #[feature] directives",
default: deny,
}),
("unknown_crate_type",
LintSpec {
lint: UnknownCrateType,
desc: "unknown crate type found in #[crate_type] directive",
default: deny,
}),
("unused_must_use",
LintSpec {
lint: UnusedMustUse,
desc: "unused result of a type flagged as #[must_use]",
default: warn,
}),
("unused_result",
LintSpec {
lint: UnusedResult,
desc: "unused result of an expression in a statement",
default: allow,
}),
("deprecated_owned_vector",
LintSpec {
lint: DeprecatedOwnedVector,
desc: "use of a `~[T]` vector",
default: allow,
}),
("raw_pointer_deriving",
LintSpec {
lint: RawPointerDeriving,
desc: "uses of #[deriving] with raw pointers are rarely correct",
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;
}
struct Context<'a> {
// All known lint modes (string versions)
dict: @LintDict,
// Current levels of each lint warning
cur: SmallIntMap<(level, LintSource)>,
// context we're checking in (used to access fields like sess)
tcx: &'a ty::ctxt,
// maps from an expression id that corresponds to a method call to the
// details of the method to be invoked
method_map: typeck::MethodMap,
// Items exported by the crate; used by the missing_doc lint.
exported_items: &'a privacy::ExportedItems,
// The id of the current `ast::StructDef` being walked.
cur_struct_def_id: ast::NodeId,
// Whether some ancestor of the current node was marked
// #[doc(hidden)].
is_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: Vec<(Lint, level, LintSource)> ,
// id of the last visited negated expression
negated_expr_id: ast::NodeId
}
impl<'a> Context<'a> {
fn get_level(&self, lint: Lint) -> level {
match self.cur.find(&(lint as uint)) {
Some(&(lvl, _)) => lvl,
None => allow
}
}
fn get_source(&self, lint: Lint) -> LintSource {
match self.cur.find(&(lint as uint)) {
Some(&(_, src)) => src,
None => Default
}
}
fn set_level(&mut self, lint: Lint, level: level, src: LintSource) {
if level == allow {
self.cur.remove(&(lint as uint));
} else {
self.cur.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;
}
}
fail!("unregistered lint {:?}", lint);
}
fn span_lint(&self, lint: Lint, span: Span, msg: &str) {
let (level, src) = match self.cur.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 => {
format!("{}, \\#[{}({})] on by default", msg,
level_to_str(level), self.lint_to_str(lint))
},
CommandLine => {
format!("{} [-{} {}]", msg,
match level {
warn => 'W', deny => 'D', forbid => 'F',
allow => fail!()
}, self.lint_to_str(lint).replace("_", "-"))
},
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 => fail!(),
}
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: |&mut Context|) {
// 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;
each_lint(&self.tcx.sess, attrs, |meta, level, lintname| {
match self.dict.find_equiv(&lintname) {
None => {
self.span_lint(
UnrecognizedLint,
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
});
let old_is_doc_hidden = self.is_doc_hidden;
self.is_doc_hidden =
self.is_doc_hidden ||
attrs.iter()
.any(|attr| {
attr.name().equiv(&("doc")) &&
match attr.meta_item_list() {
None => false,
Some(l) => {
attr::contains_name(l.as_slice(), "hidden")
}
}
});
f(self);
// rollback
self.is_doc_hidden = old_is_doc_hidden;
for _ in range(0, pushed) {
let (lint, lvl, src) = self.lint_stack.pop().unwrap();
self.set_level(lint, lvl, src);
}
}
fn visit_ids(&self, f: |&mut ast_util::IdVisitor<Context>|) {
let mut v = ast_util::IdVisitor {
operation: self,
pass_through_items: false,
visited_outermost: false,
};
f(&mut v);
}
}
// Check that every lint from the list of attributes satisfies `f`.
// Return true if that's the case. Otherwise return false.
pub fn each_lint(sess: &session::Session,
attrs: &[ast::Attribute],
f: |@ast::MetaItem, level, InternedString| -> 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| m.name().equiv(&level_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(ref lintname) => {
if !f(*meta, level, (*lintname).clone()) {
return false;
}
}
_ => {
sess.span_err(meta.span, "malformed lint attribute");
}
}
}
}
}
true
}
// Check from a list of attributes if it contains the appropriate
// `#[level(lintname)]` attribute (e.g. `#[allow(dead_code)]).
pub fn contains_lint(attrs: &[ast::Attribute],
level: level,
lintname: &'static str)
-> bool {
let level_name = level_to_str(level);
for attr in attrs.iter().filter(|m| m.name().equiv(&level_name)) {
if attr.meta_item_list().is_none() {
continue
}
let list = attr.meta_item_list().unwrap();
for meta_item in list.iter() {
if meta_item.name().equiv(&lintname) {
return true;
}
}
}
false
}
fn check_while_true_expr(cx: &Context, e: &ast::Expr) {
match e.node {
ast::ExprWhile(cond, _) => {
match cond.node {
ast::ExprLit(lit) => {
match lit.node {
ast::LitBool(true) => {
cx.span_lint(WhileTrue,
e.span,
"denote infinite loops with loop \
{ ... }");
}
_ => {}
}
}
_ => ()
}
}
_ => ()
}
}
impl<'a> AstConv for Context<'a>{
fn tcx<'a>(&'a self) -> &'a ty::ctxt { self.tcx }
fn get_item_ty(&self, id: ast::DefId) -> ty::ty_param_bounds_and_ty {
ty::lookup_item_type(self.tcx, id)
}
fn get_trait_def(&self, id: ast::DefId) -> @ty::TraitDef {
ty::lookup_trait_def(self.tcx, id)
}
fn ty_infer(&self, _span: Span) -> ty::t {
infer::new_infer_ctxt(self.tcx).next_ty_var()
}
}
fn check_unused_casts(cx: &Context, e: &ast::Expr) {
return match e.node {
ast::ExprCast(expr, ty) => {
let t_t = ast_ty_to_ty(cx, &infer::new_infer_ctxt(cx.tcx), ty);
if ty::get(ty::expr_ty(cx.tcx, expr)).sty == ty::get(t_t).sty {
cx.span_lint(UnnecessaryTypecast, ty.span,
"unnecessary type cast");
}
}
_ => ()
};
}
fn check_type_limits(cx: &Context, e: &ast::Expr) {
return match e.node {
ast::ExprBinary(binop, l, r) => {
if is_comparison(binop) && !check_limits(cx.tcx, binop, l, r) {
cx.span_lint(TypeLimits, e.span,
"comparison is useless due to type limits");
}
},
ast::ExprLit(lit) => {
match ty::get(ty::expr_ty(cx.tcx, e)).sty {
ty::ty_int(t) => {
let int_type = if t == ast::TyI {
cx.tcx.sess.targ_cfg.int_type
} else { t };
let (min, max) = int_ty_range(int_type);
let mut lit_val: i64 = match lit.node {
ast::LitInt(v, _) => v,
ast::LitUint(v, _) => v as i64,
ast::LitIntUnsuffixed(v) => v,
_ => fail!()
};
if cx.negated_expr_id == e.id {
lit_val *= -1;
}
if lit_val < min || lit_val > max {
cx.span_lint(TypeOverflow, e.span,
"literal out of range for its type");
}
},
ty::ty_uint(t) => {
let uint_type = if t == ast::TyU {
cx.tcx.sess.targ_cfg.uint_type
} else { t };
let (min, max) = uint_ty_range(uint_type);
let lit_val: u64 = match lit.node {
ast::LitInt(v, _) => v as u64,
ast::LitUint(v, _) => v,
ast::LitIntUnsuffixed(v) => v as u64,
_ => fail!()
};
if lit_val < min || lit_val > max {
cx.span_lint(TypeOverflow, e.span,
"literal out of range for its type");
}
},
_ => ()
};
},
_ => ()
};
fn is_valid<T:cmp::Ord>(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,
_ => fail!()
}
}
fn rev_binop(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(int_ty: ast::IntTy) -> (i64, i64) {
match int_ty {
ast::TyI => (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::TyU => (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 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::get(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(li) => match li.node {
ast::LitInt(v, _) => v,
ast::LitUint(v, _) => v as i64,
ast::LitIntUnsuffixed(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::ExprLit(li) => match li.node {
ast::LitInt(v, _) => v as u64,
ast::LitUint(v, _) => v,
ast::LitIntUnsuffixed(v) => v as u64,
_ => return true
},
_ => fail!()
};
is_valid(norm_binop, lit_val, min, max)
}
_ => true
}
}
fn is_comparison(binop: ast::BinOp) -> bool {
match binop {
ast::BiEq | ast::BiLt | ast::BiLe |
ast::BiNe | ast::BiGe | ast::BiGt => true,
_ => false
}
}
}
fn check_item_ctypes(cx: &Context, it: &ast::Item) {
fn check_ty(cx: &Context, ty: &ast::Ty) {
match ty.node {
ast::TyPath(_, _, id) => {
match cx.tcx.def_map.borrow().get_copy(&id) {
ast::DefPrimTy(ast::TyInt(ast::TyI)) => {
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::TyUint(ast::TyU)) => {
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::DefTy(def_id) => {
if !adt::is_ffi_safe(cx.tcx, def_id) {
cx.span_lint(CTypes, ty.span,
"found enum type without foreign-function-safe \
representation annotation in foreign module");
// hmm... this message could be more helpful
}
}
_ => ()
}
}
ast::TyPtr(ref mt) => { check_ty(cx, mt.ty) }
_ => {}
}
}
fn check_foreign_fn(cx: &Context, decl: &ast::FnDecl) {
for input in decl.inputs.iter() {
check_ty(cx, input.ty);
}
check_ty(cx, decl.output)
}
match it.node {
ast::ItemForeignMod(ref nmod) if !nmod.abis.is_intrinsic() => {
for ni in nmod.items.iter() {
match ni.node {
ast::ForeignItemFn(decl, _) => check_foreign_fn(cx, decl),
ast::ForeignItemStatic(t, _) => check_ty(cx, t)
}
}
}
_ => {/* nothing to do */ }
}
}
fn check_heap_type(cx: &Context, span: Span, ty: ty::t) {
let xs = [ManagedHeapMemory, OwnedHeapMemory, HeapMemory];
for &lint in xs.iter() {
if cx.get_level(lint) == allow { continue }
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(_) | ty::ty_str(ty::vstore_uniq) |
ty::ty_vec(_, ty::vstore_uniq) |
ty::ty_trait(~ty::TyTrait { store: ty::UniqTraitStore, .. }) => {
n_uniq += 1;
}
ty::ty_closure(ref c) if c.sigil == ast::OwnedSigil => {
n_uniq += 1;
}
_ => ()
};
t
});
if n_uniq > 0 && lint != ManagedHeapMemory {
let s = ty_to_str(cx.tcx, ty);
let m = format!("type uses owned (~ type) pointers: {}", s);
cx.span_lint(lint, span, m);
}
if n_box > 0 && lint != OwnedHeapMemory {
let s = ty_to_str(cx.tcx, ty);
let m = format!("type uses managed (@ type) pointers: {}", s);
cx.span_lint(lint, span, m);
}
}
}
fn check_heap_item(cx: &Context, it: &ast::Item) {
match it.node {
ast::ItemFn(..) |
ast::ItemTy(..) |
ast::ItemEnum(..) |
ast::ItemStruct(..) => 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(struct_def, _) => {
for struct_field in struct_def.fields.iter() {
check_heap_type(cx, struct_field.span,
ty::node_id_to_type(cx.tcx,
struct_field.node.id));
}
}
_ => ()
}
}
struct RawPtrDerivingVisitor<'a> {
cx: &'a Context<'a>
}
impl<'a> Visitor<()> for RawPtrDerivingVisitor<'a> {
fn visit_ty(&mut self, ty: &ast::Ty, _: ()) {
static MSG: &'static str = "use of `#[deriving]` with a raw pointer";
match ty.node {
ast::TyPtr(..) => self.cx.span_lint(RawPointerDeriving, 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, _: ()) {}
}
fn check_raw_ptr_deriving(cx: &Context, item: &ast::Item) {
if !attr::contains_name(item.attrs.as_slice(), "deriving") {
return
}
match item.node {
ast::ItemStruct(..) | ast::ItemEnum(..) => {
let mut visitor = RawPtrDerivingVisitor { cx: cx };
visit::walk_item(&mut visitor, item, ());
}
_ => {}
}
}