rust/src/libsyntax/ast_util.rs
Kiet Tran 9faa2a58f2 Suggest explicit lifetime parameter on some errors
Some types of error are caused by missing lifetime parameter on function
or method declaration. In such cases, this commit generates some
suggestion about what the function declaration could be. This does not
support method declaration yet.
2014-03-12 16:34:05 -04:00

733 lines
20 KiB
Rust

// Copyright 2012-2013 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 ast::*;
use ast;
use ast_util;
use codemap;
use codemap::Span;
use opt_vec;
use parse::token;
use print::pprust;
use visit::Visitor;
use visit;
use std::cell::Cell;
use std::cmp;
use std::u32;
use std::vec_ng::Vec;
pub fn path_name_i(idents: &[Ident]) -> ~str {
// FIXME: Bad copies (#2543 -- same for everything else that says "bad")
idents.map(|i| {
token::get_ident(*i).get().to_str()
}).connect("::")
}
// totally scary function: ignores all but the last element, should have
// a different name
pub fn path_to_ident(path: &Path) -> Ident {
path.segments.last().unwrap().identifier
}
pub fn local_def(id: NodeId) -> DefId {
ast::DefId { krate: LOCAL_CRATE, node: id }
}
pub fn is_local(did: ast::DefId) -> bool { did.krate == LOCAL_CRATE }
pub fn stmt_id(s: &Stmt) -> NodeId {
match s.node {
StmtDecl(_, id) => id,
StmtExpr(_, id) => id,
StmtSemi(_, id) => id,
StmtMac(..) => fail!("attempted to analyze unexpanded stmt")
}
}
pub fn variant_def_ids(d: Def) -> Option<(DefId, DefId)> {
match d {
DefVariant(enum_id, var_id, _) => {
Some((enum_id, var_id))
}
_ => None
}
}
pub fn def_id_of_def(d: Def) -> DefId {
match d {
DefFn(id, _) | DefStaticMethod(id, _, _) | DefMod(id) |
DefForeignMod(id) | DefStatic(id, _) |
DefVariant(_, id, _) | DefTy(id) | DefTyParam(id, _) |
DefUse(id) | DefStruct(id) | DefTrait(id) | DefMethod(id, _) => {
id
}
DefArg(id, _) | DefLocal(id, _) | DefSelfTy(id)
| DefUpvar(id, _, _, _) | DefBinding(id, _) | DefRegion(id)
| DefTyParamBinder(id) | DefLabel(id) => {
local_def(id)
}
DefPrimTy(_) => fail!()
}
}
pub fn binop_to_str(op: BinOp) -> &'static str {
match op {
BiAdd => "+",
BiSub => "-",
BiMul => "*",
BiDiv => "/",
BiRem => "%",
BiAnd => "&&",
BiOr => "||",
BiBitXor => "^",
BiBitAnd => "&",
BiBitOr => "|",
BiShl => "<<",
BiShr => ">>",
BiEq => "==",
BiLt => "<",
BiLe => "<=",
BiNe => "!=",
BiGe => ">=",
BiGt => ">"
}
}
pub fn lazy_binop(b: BinOp) -> bool {
match b {
BiAnd => true,
BiOr => true,
_ => false
}
}
pub fn is_shift_binop(b: BinOp) -> bool {
match b {
BiShl => true,
BiShr => true,
_ => false
}
}
pub fn unop_to_str(op: UnOp) -> &'static str {
match op {
UnBox => "@",
UnUniq => "~",
UnDeref => "*",
UnNot => "!",
UnNeg => "-",
}
}
pub fn is_path(e: @Expr) -> bool {
return match e.node { ExprPath(_) => true, _ => false };
}
pub fn int_ty_to_str(t: IntTy) -> ~str {
match t {
TyI => ~"",
TyI8 => ~"i8",
TyI16 => ~"i16",
TyI32 => ~"i32",
TyI64 => ~"i64"
}
}
pub fn int_ty_max(t: IntTy) -> u64 {
match t {
TyI8 => 0x80u64,
TyI16 => 0x8000u64,
TyI | TyI32 => 0x80000000u64, // actually ni about TyI
TyI64 => 0x8000000000000000u64
}
}
pub fn uint_ty_to_str(t: UintTy) -> ~str {
match t {
TyU => ~"u",
TyU8 => ~"u8",
TyU16 => ~"u16",
TyU32 => ~"u32",
TyU64 => ~"u64"
}
}
pub fn uint_ty_max(t: UintTy) -> u64 {
match t {
TyU8 => 0xffu64,
TyU16 => 0xffffu64,
TyU | TyU32 => 0xffffffffu64, // actually ni about TyU
TyU64 => 0xffffffffffffffffu64
}
}
pub fn float_ty_to_str(t: FloatTy) -> ~str {
match t { TyF32 => ~"f32", TyF64 => ~"f64" }
}
pub fn is_call_expr(e: @Expr) -> bool {
match e.node { ExprCall(..) => true, _ => false }
}
pub fn block_from_expr(e: @Expr) -> P<Block> {
P(Block {
view_items: Vec::new(),
stmts: Vec::new(),
expr: Some(e),
id: e.id,
rules: DefaultBlock,
span: e.span
})
}
pub fn ident_to_path(s: Span, identifier: Ident) -> Path {
ast::Path {
span: s,
global: false,
segments: vec!(
ast::PathSegment {
identifier: identifier,
lifetimes: Vec::new(),
types: opt_vec::Empty,
}
),
}
}
pub fn ident_to_pat(id: NodeId, s: Span, i: Ident) -> @Pat {
@ast::Pat { id: id,
node: PatIdent(BindByValue(MutImmutable), ident_to_path(s, i), None),
span: s }
}
pub fn name_to_dummy_lifetime(name: Name) -> Lifetime {
Lifetime { id: DUMMY_NODE_ID,
span: codemap::DUMMY_SP,
name: name }
}
pub fn is_unguarded(a: &Arm) -> bool {
match a.guard {
None => true,
_ => false
}
}
pub fn unguarded_pat(a: &Arm) -> Option<Vec<@Pat> > {
if is_unguarded(a) {
Some(/* FIXME (#2543) */ a.pats.clone())
} else {
None
}
}
/// Generate a "pretty" name for an `impl` from its type and trait.
/// This is designed so that symbols of `impl`'d methods give some
/// hint of where they came from, (previously they would all just be
/// listed as `__extensions__::method_name::hash`, with no indication
/// of the type).
pub fn impl_pretty_name(trait_ref: &Option<TraitRef>, ty: &Ty) -> Ident {
let mut pretty = pprust::ty_to_str(ty);
match *trait_ref {
Some(ref trait_ref) => {
pretty.push_char('.');
pretty.push_str(pprust::path_to_str(&trait_ref.path));
}
None => {}
}
token::gensym_ident(pretty)
}
pub fn public_methods(ms: Vec<@Method> ) -> Vec<@Method> {
ms.move_iter().filter(|m| {
match m.vis {
Public => true,
_ => false
}
}).collect()
}
// extract a TypeMethod from a TraitMethod. if the TraitMethod is
// a default, pull out the useful fields to make a TypeMethod
pub fn trait_method_to_ty_method(method: &TraitMethod) -> TypeMethod {
match *method {
Required(ref m) => (*m).clone(),
Provided(ref m) => {
TypeMethod {
ident: m.ident,
attrs: m.attrs.clone(),
purity: m.purity,
decl: m.decl,
generics: m.generics.clone(),
explicit_self: m.explicit_self,
id: m.id,
span: m.span,
}
}
}
}
pub fn split_trait_methods(trait_methods: &[TraitMethod])
-> (Vec<TypeMethod> , Vec<@Method> ) {
let mut reqd = Vec::new();
let mut provd = Vec::new();
for trt_method in trait_methods.iter() {
match *trt_method {
Required(ref tm) => reqd.push((*tm).clone()),
Provided(m) => provd.push(m)
}
};
(reqd, provd)
}
pub fn struct_field_visibility(field: ast::StructField) -> Visibility {
match field.node.kind {
ast::NamedField(_, visibility) => visibility,
ast::UnnamedField => ast::Public
}
}
/// Maps a binary operator to its precedence
pub fn operator_prec(op: ast::BinOp) -> uint {
match op {
// 'as' sits here with 12
BiMul | BiDiv | BiRem => 11u,
BiAdd | BiSub => 10u,
BiShl | BiShr => 9u,
BiBitAnd => 8u,
BiBitXor => 7u,
BiBitOr => 6u,
BiLt | BiLe | BiGe | BiGt => 4u,
BiEq | BiNe => 3u,
BiAnd => 2u,
BiOr => 1u
}
}
/// Precedence of the `as` operator, which is a binary operator
/// not appearing in the prior table.
pub static as_prec: uint = 12u;
pub fn empty_generics() -> Generics {
Generics {lifetimes: Vec::new(),
ty_params: opt_vec::Empty}
}
// ______________________________________________________________________
// Enumerating the IDs which appear in an AST
#[deriving(Encodable, Decodable)]
pub struct IdRange {
min: NodeId,
max: NodeId,
}
impl IdRange {
pub fn max() -> IdRange {
IdRange {
min: u32::MAX,
max: u32::MIN,
}
}
pub fn empty(&self) -> bool {
self.min >= self.max
}
pub fn add(&mut self, id: NodeId) {
self.min = cmp::min(self.min, id);
self.max = cmp::max(self.max, id + 1);
}
}
pub trait IdVisitingOperation {
fn visit_id(&self, node_id: NodeId);
}
pub struct IdVisitor<'a, O> {
operation: &'a O,
pass_through_items: bool,
visited_outermost: bool,
}
impl<'a, O: IdVisitingOperation> IdVisitor<'a, O> {
fn visit_generics_helper(&self, generics: &Generics) {
for type_parameter in generics.ty_params.iter() {
self.operation.visit_id(type_parameter.id)
}
for lifetime in generics.lifetimes.iter() {
self.operation.visit_id(lifetime.id)
}
}
}
impl<'a, O: IdVisitingOperation> Visitor<()> for IdVisitor<'a, O> {
fn visit_mod(&mut self,
module: &Mod,
_: Span,
node_id: NodeId,
env: ()) {
self.operation.visit_id(node_id);
visit::walk_mod(self, module, env)
}
fn visit_view_item(&mut self, view_item: &ViewItem, env: ()) {
match view_item.node {
ViewItemExternCrate(_, _, node_id) => {
self.operation.visit_id(node_id)
}
ViewItemUse(ref view_paths) => {
for view_path in view_paths.iter() {
match view_path.node {
ViewPathSimple(_, _, node_id) |
ViewPathGlob(_, node_id) => {
self.operation.visit_id(node_id)
}
ViewPathList(_, ref paths, node_id) => {
self.operation.visit_id(node_id);
for path in paths.iter() {
self.operation.visit_id(path.node.id)
}
}
}
}
}
}
visit::walk_view_item(self, view_item, env)
}
fn visit_foreign_item(&mut self, foreign_item: &ForeignItem, env: ()) {
self.operation.visit_id(foreign_item.id);
visit::walk_foreign_item(self, foreign_item, env)
}
fn visit_item(&mut self, item: &Item, env: ()) {
if !self.pass_through_items {
if self.visited_outermost {
return
} else {
self.visited_outermost = true
}
}
self.operation.visit_id(item.id);
match item.node {
ItemEnum(ref enum_definition, _) => {
for variant in enum_definition.variants.iter() {
self.operation.visit_id(variant.node.id)
}
}
_ => {}
}
visit::walk_item(self, item, env);
self.visited_outermost = false
}
fn visit_local(&mut self, local: &Local, env: ()) {
self.operation.visit_id(local.id);
visit::walk_local(self, local, env)
}
fn visit_block(&mut self, block: &Block, env: ()) {
self.operation.visit_id(block.id);
visit::walk_block(self, block, env)
}
fn visit_stmt(&mut self, statement: &Stmt, env: ()) {
self.operation.visit_id(ast_util::stmt_id(statement));
visit::walk_stmt(self, statement, env)
}
fn visit_pat(&mut self, pattern: &Pat, env: ()) {
self.operation.visit_id(pattern.id);
visit::walk_pat(self, pattern, env)
}
fn visit_expr(&mut self, expression: &Expr, env: ()) {
self.operation.visit_id(expression.id);
visit::walk_expr(self, expression, env)
}
fn visit_ty(&mut self, typ: &Ty, env: ()) {
self.operation.visit_id(typ.id);
match typ.node {
TyPath(_, _, id) => self.operation.visit_id(id),
_ => {}
}
visit::walk_ty(self, typ, env)
}
fn visit_generics(&mut self, generics: &Generics, env: ()) {
self.visit_generics_helper(generics);
visit::walk_generics(self, generics, env)
}
fn visit_fn(&mut self,
function_kind: &visit::FnKind,
function_declaration: &FnDecl,
block: &Block,
span: Span,
node_id: NodeId,
env: ()) {
if !self.pass_through_items {
match *function_kind {
visit::FkMethod(..) if self.visited_outermost => return,
visit::FkMethod(..) => self.visited_outermost = true,
_ => {}
}
}
self.operation.visit_id(node_id);
match *function_kind {
visit::FkItemFn(_, generics, _, _) |
visit::FkMethod(_, generics, _) => {
self.visit_generics_helper(generics)
}
visit::FkFnBlock => {}
}
for argument in function_declaration.inputs.iter() {
self.operation.visit_id(argument.id)
}
visit::walk_fn(self,
function_kind,
function_declaration,
block,
span,
node_id,
env);
if !self.pass_through_items {
match *function_kind {
visit::FkMethod(..) => self.visited_outermost = false,
_ => {}
}
}
}
fn visit_struct_field(&mut self, struct_field: &StructField, env: ()) {
self.operation.visit_id(struct_field.node.id);
visit::walk_struct_field(self, struct_field, env)
}
fn visit_struct_def(&mut self,
struct_def: &StructDef,
ident: ast::Ident,
generics: &ast::Generics,
id: NodeId,
_: ()) {
self.operation.visit_id(id);
struct_def.ctor_id.map(|ctor_id| self.operation.visit_id(ctor_id));
visit::walk_struct_def(self, struct_def, ident, generics, id, ());
}
fn visit_trait_method(&mut self, tm: &ast::TraitMethod, _: ()) {
match *tm {
ast::Required(ref m) => self.operation.visit_id(m.id),
ast::Provided(ref m) => self.operation.visit_id(m.id),
}
visit::walk_trait_method(self, tm, ());
}
}
pub fn visit_ids_for_inlined_item<O: IdVisitingOperation>(item: &InlinedItem,
operation: &O) {
let mut id_visitor = IdVisitor {
operation: operation,
pass_through_items: true,
visited_outermost: false,
};
visit::walk_inlined_item(&mut id_visitor, item, ());
}
struct IdRangeComputingVisitor {
result: Cell<IdRange>,
}
impl IdVisitingOperation for IdRangeComputingVisitor {
fn visit_id(&self, id: NodeId) {
let mut id_range = self.result.get();
id_range.add(id);
self.result.set(id_range)
}
}
pub fn compute_id_range_for_inlined_item(item: &InlinedItem) -> IdRange {
let visitor = IdRangeComputingVisitor {
result: Cell::new(IdRange::max())
};
visit_ids_for_inlined_item(item, &visitor);
visitor.result.get()
}
pub fn is_item_impl(item: @ast::Item) -> bool {
match item.node {
ItemImpl(..) => true,
_ => false
}
}
pub fn walk_pat(pat: &Pat, it: |&Pat| -> bool) -> bool {
if !it(pat) {
return false;
}
match pat.node {
PatIdent(_, _, Some(p)) => walk_pat(p, it),
PatStruct(_, ref fields, _) => {
fields.iter().advance(|f| walk_pat(f.pat, |p| it(p)))
}
PatEnum(_, Some(ref s)) | PatTup(ref s) => {
s.iter().advance(|&p| walk_pat(p, |p| it(p)))
}
PatUniq(s) | PatRegion(s) => {
walk_pat(s, it)
}
PatVec(ref before, ref slice, ref after) => {
before.iter().advance(|&p| walk_pat(p, |p| it(p))) &&
slice.iter().advance(|&p| walk_pat(p, |p| it(p))) &&
after.iter().advance(|&p| walk_pat(p, |p| it(p)))
}
PatWild | PatWildMulti | PatLit(_) | PatRange(_, _) | PatIdent(_, _, _) |
PatEnum(_, _) => {
true
}
}
}
pub trait EachViewItem {
fn each_view_item(&self, f: |&ast::ViewItem| -> bool) -> bool;
}
struct EachViewItemData<'a> {
callback: 'a |&ast::ViewItem| -> bool,
}
impl<'a> Visitor<()> for EachViewItemData<'a> {
fn visit_view_item(&mut self, view_item: &ast::ViewItem, _: ()) {
let _ = (self.callback)(view_item);
}
}
impl EachViewItem for ast::Crate {
fn each_view_item(&self, f: |&ast::ViewItem| -> bool) -> bool {
let mut visit = EachViewItemData {
callback: f,
};
visit::walk_crate(&mut visit, self, ());
true
}
}
pub fn view_path_id(p: &ViewPath) -> NodeId {
match p.node {
ViewPathSimple(_, _, id) | ViewPathGlob(_, id)
| ViewPathList(_, _, id) => id
}
}
/// Returns true if the given struct def is tuple-like; i.e. that its fields
/// are unnamed.
pub fn struct_def_is_tuple_like(struct_def: &ast::StructDef) -> bool {
struct_def.ctor_id.is_some()
}
/// Returns true if the given pattern consists solely of an identifier
/// and false otherwise.
pub fn pat_is_ident(pat: @ast::Pat) -> bool {
match pat.node {
ast::PatIdent(..) => true,
_ => false,
}
}
// are two paths equal when compared unhygienically?
// since I'm using this to replace ==, it seems appropriate
// to compare the span, global, etc. fields as well.
pub fn path_name_eq(a : &ast::Path, b : &ast::Path) -> bool {
(a.span == b.span)
&& (a.global == b.global)
&& (segments_name_eq(a.segments.as_slice(), b.segments.as_slice()))
}
// are two arrays of segments equal when compared unhygienically?
pub fn segments_name_eq(a : &[ast::PathSegment], b : &[ast::PathSegment]) -> bool {
if a.len() != b.len() {
false
} else {
for (idx,seg) in a.iter().enumerate() {
if (seg.identifier.name != b[idx].identifier.name)
// FIXME #7743: ident -> name problems in lifetime comparison?
|| (seg.lifetimes != b[idx].lifetimes)
// can types contain idents?
|| (seg.types != b[idx].types) {
return false;
}
}
true
}
}
// Returns true if this literal is a string and false otherwise.
pub fn lit_is_str(lit: @Lit) -> bool {
match lit.node {
LitStr(..) => true,
_ => false,
}
}
pub fn get_inner_tys(ty: P<Ty>) -> Vec<P<Ty>> {
match ty.node {
ast::TyRptr(_, mut_ty) | ast::TyPtr(mut_ty) => {
vec!(mut_ty.ty)
}
ast::TyBox(ty)
| ast::TyVec(ty)
| ast::TyUniq(ty)
| ast::TyFixedLengthVec(ty, _) => vec!(ty),
ast::TyTup(ref tys) => tys.clone(),
_ => Vec::new()
}
}
#[cfg(test)]
mod test {
use ast::*;
use super::*;
use opt_vec;
use std::vec_ng::Vec;
fn ident_to_segment(id : &Ident) -> PathSegment {
PathSegment {identifier:id.clone(),
lifetimes: Vec::new(),
types: opt_vec::Empty}
}
#[test] fn idents_name_eq_test() {
assert!(segments_name_eq([Ident{name:3,ctxt:4},
Ident{name:78,ctxt:82}].map(ident_to_segment),
[Ident{name:3,ctxt:104},
Ident{name:78,ctxt:182}].map(ident_to_segment)));
assert!(!segments_name_eq([Ident{name:3,ctxt:4},
Ident{name:78,ctxt:82}].map(ident_to_segment),
[Ident{name:3,ctxt:104},
Ident{name:77,ctxt:182}].map(ident_to_segment)));
}
}