rust/src/libsyntax/ast_util.rs
2014-07-09 00:49:54 -07:00

768 lines
22 KiB
Rust

// 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.
use ast::*;
use ast;
use ast_util;
use attr::{InlineNever, InlineNone};
use attr;
use codemap;
use codemap::Span;
use owned_slice::OwnedSlice;
use parse::token;
use print::pprust;
use visit::Visitor;
use visit;
use std::cell::Cell;
use std::cmp;
use std::gc::{Gc, GC};
use std::u32;
pub fn path_name_i(idents: &[Ident]) -> String {
// FIXME: Bad copies (#2543 -- same for everything else that says "bad")
idents.iter().map(|i| {
token::get_ident(*i).get().to_string()
}).collect::<Vec<String>>().connect("::")
}
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 binop_to_string(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_string(op: UnOp) -> &'static str {
match op {
UnBox => "box(GC) ",
UnUniq => "box() ",
UnDeref => "*",
UnNot => "!",
UnNeg => "-",
}
}
pub fn is_path(e: Gc<Expr>) -> bool {
return match e.node { ExprPath(_) => true, _ => false };
}
/// Get a string representation of a signed int type, with its value.
/// We want to avoid "45int" and "-3int" in favor of "45" and "-3"
pub fn int_ty_to_string(t: IntTy, val: Option<i64>) -> String {
let s = match t {
TyI if val.is_some() => "i",
TyI => "int",
TyI8 => "i8",
TyI16 => "i16",
TyI32 => "i32",
TyI64 => "i64"
};
match val {
// cast to a u64 so we can correctly print INT64_MIN. All integral types
// are parsed as u64, so we wouldn't want to print an extra negative
// sign.
Some(n) => format!("{}{}", n as u64, s),
None => s.to_string()
}
}
pub fn int_ty_max(t: IntTy) -> u64 {
match t {
TyI8 => 0x80u64,
TyI16 => 0x8000u64,
TyI | TyI32 => 0x80000000u64, // actually ni about TyI
TyI64 => 0x8000000000000000u64
}
}
/// Get a string representation of an unsigned int type, with its value.
/// We want to avoid "42uint" in favor of "42u"
pub fn uint_ty_to_string(t: UintTy, val: Option<u64>) -> String {
let s = match t {
TyU if val.is_some() => "u",
TyU => "uint",
TyU8 => "u8",
TyU16 => "u16",
TyU32 => "u32",
TyU64 => "u64"
};
match val {
Some(n) => format!("{}{}", n, s),
None => s.to_string()
}
}
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_string(t: FloatTy) -> String {
match t {
TyF32 => "f32".to_string(),
TyF64 => "f64".to_string(),
}
}
pub fn is_call_expr(e: Gc<Expr>) -> bool {
match e.node { ExprCall(..) => true, _ => false }
}
pub fn block_from_expr(e: Gc<Expr>) -> P<Block> {
P(Block {
view_items: Vec::new(),
stmts: Vec::new(),
expr: Some(e),
id: e.id,
rules: DefaultBlock,
span: e.span
})
}
// convert a span and an identifier to the corresponding
// 1-segment path
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: OwnedSlice::empty(),
}
),
}
}
pub fn ident_to_pat(id: NodeId, s: Span, i: Ident) -> Gc<Pat> {
box(GC) ast::Pat { id: id,
node: PatIdent(BindByValue(MutImmutable), codemap::Spanned{span:s, node: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<Gc<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_string(ty);
match *trait_ref {
Some(ref trait_ref) => {
pretty.push_char('.');
pretty.push_str(pprust::path_to_string(&trait_ref.path).as_slice());
}
None => {}
}
token::gensym_ident(pretty.as_slice())
}
pub fn public_methods(ms: Vec<Gc<Method>> ) -> Vec<Gc<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(),
fn_style: m.fn_style,
decl: m.decl,
generics: m.generics.clone(),
explicit_self: m.explicit_self,
id: m.id,
span: m.span,
vis: m.vis,
}
}
}
}
pub fn split_trait_methods(trait_methods: &[TraitMethod])
-> (Vec<TypeMethod> , Vec<Gc<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(_, v) | ast::UnnamedField(v) => v
}
}
/// 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: OwnedSlice::empty()}
}
// ______________________________________________________________________
// Enumerating the IDs which appear in an AST
#[deriving(Encodable, Decodable)]
pub struct IdRange {
pub min: NodeId,
pub 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> {
pub operation: &'a O,
pub pass_through_items: bool,
pub 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: ()) {
if !self.pass_through_items {
if self.visited_outermost {
return;
} else {
self.visited_outermost = true;
}
}
match view_item.node {
ViewItemExternCrate(_, _, node_id) => {
self.operation.visit_id(node_id)
}
ViewItemUse(ref view_path) => {
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);
self.visited_outermost = false;
}
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,
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,
_: ast::Ident,
_: &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, ());
}
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 compute_id_range_for_fn_body(fk: &visit::FnKind,
decl: &FnDecl,
body: &Block,
sp: Span,
id: NodeId)
-> IdRange
{
/*!
* Computes the id range for a single fn body,
* ignoring nested items.
*/
let visitor = IdRangeComputingVisitor {
result: Cell::new(IdRange::max())
};
let mut id_visitor = IdVisitor {
operation: &visitor,
pass_through_items: false,
visited_outermost: false,
};
id_visitor.visit_fn(fk, decl, body, sp, id, ());
visitor.result.get()
}
pub fn is_item_impl(item: Gc<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(ref 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)))
}
PatBox(ref s) | PatRegion(ref 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)))
}
PatMac(_) => fail!("attempted to analyze unexpanded pattern"),
PatWild | PatWildMulti | PatLit(_) | PatRange(_, _) | PatIdent(_, _, _) |
PatEnum(_, _) => {
true
}
}
}
pub trait EachViewItem {
fn each_view_item(&self, f: |&ast::ViewItem| -> bool) -> bool;
}
struct EachViewItemData<'a> {
callback: |&ast::ViewItem|: 'a -> 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: Gc<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: Gc<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(),
ast::TyParen(ty) => get_inner_tys(ty),
_ => Vec::new()
}
}
/// Returns true if the static with the given mutability and attributes
/// has a significant address and false otherwise.
pub fn static_has_significant_address(mutbl: ast::Mutability,
attrs: &[ast::Attribute])
-> bool {
if mutbl == ast::MutMutable {
return true
}
let inline = attr::find_inline_attr(attrs);
inline == InlineNever || inline == InlineNone
}
#[cfg(test)]
mod test {
use ast::*;
use super::*;
use owned_slice::OwnedSlice;
fn ident_to_segment(id : &Ident) -> PathSegment {
PathSegment {identifier:id.clone(),
lifetimes: Vec::new(),
types: OwnedSlice::empty()}
}
#[test] fn idents_name_eq_test() {
assert!(segments_name_eq(
[Ident{name:Name(3),ctxt:4}, Ident{name:Name(78),ctxt:82}]
.iter().map(ident_to_segment).collect::<Vec<PathSegment>>().as_slice(),
[Ident{name:Name(3),ctxt:104}, Ident{name:Name(78),ctxt:182}]
.iter().map(ident_to_segment).collect::<Vec<PathSegment>>().as_slice()));
assert!(!segments_name_eq(
[Ident{name:Name(3),ctxt:4}, Ident{name:Name(78),ctxt:82}]
.iter().map(ident_to_segment).collect::<Vec<PathSegment>>().as_slice(),
[Ident{name:Name(3),ctxt:104}, Ident{name:Name(77),ctxt:182}]
.iter().map(ident_to_segment).collect::<Vec<PathSegment>>().as_slice()));
}
}