blob: 8ac103856dcd17fe4b799789066cc993132f689a [file] [log] [blame]
//! A Folder represents an AST->AST fold; it accepts an AST piece,
//! and returns a piece of the same type. So, for instance, macro
//! expansion is a Folder that walks over an AST and produces another
//! AST.
//!
//! Note: using a Folder (other than the MacroExpander Folder) on
//! an AST before macro expansion is probably a bad idea. For instance,
//! a folder renaming item names in a module will miss all of those
//! that are created by the expansion of a macro.
use ast::*;
use ast;
use syntax_pos::Span;
use source_map::{Spanned, respan};
use parse::token::{self, Token};
use ptr::P;
use smallvec::{Array, SmallVec};
use symbol::keywords;
use ThinVec;
use tokenstream::*;
use util::move_map::MoveMap;
use rustc_data_structures::sync::Lrc;
pub trait ExpectOne<A: Array> {
fn expect_one(self, err: &'static str) -> A::Item;
}
impl<A: Array> ExpectOne<A> for SmallVec<A> {
fn expect_one(self, err: &'static str) -> A::Item {
assert!(self.len() == 1, err);
self.into_iter().next().unwrap()
}
}
pub trait Folder : Sized {
// Any additions to this trait should happen in form
// of a call to a public `noop_*` function that only calls
// out to the folder again, not other `noop_*` functions.
//
// This is a necessary API workaround to the problem of not
// being able to call out to the super default method
// in an overridden default method.
fn fold_crate(&mut self, c: Crate) -> Crate {
noop_fold_crate(c, self)
}
fn fold_meta_items(&mut self, meta_items: Vec<MetaItem>) -> Vec<MetaItem> {
noop_fold_meta_items(meta_items, self)
}
fn fold_meta_list_item(&mut self, list_item: NestedMetaItem) -> NestedMetaItem {
noop_fold_meta_list_item(list_item, self)
}
fn fold_meta_item(&mut self, meta_item: MetaItem) -> MetaItem {
noop_fold_meta_item(meta_item, self)
}
fn fold_use_tree(&mut self, use_tree: UseTree) -> UseTree {
noop_fold_use_tree(use_tree, self)
}
fn fold_foreign_item(&mut self, ni: ForeignItem) -> SmallVec<[ForeignItem; 1]> {
noop_fold_foreign_item(ni, self)
}
fn fold_foreign_item_simple(&mut self, ni: ForeignItem) -> ForeignItem {
noop_fold_foreign_item_simple(ni, self)
}
fn fold_item(&mut self, i: P<Item>) -> SmallVec<[P<Item>; 1]> {
noop_fold_item(i, self)
}
fn fold_item_simple(&mut self, i: Item) -> Item {
noop_fold_item_simple(i, self)
}
fn fold_fn_header(&mut self, header: FnHeader) -> FnHeader {
noop_fold_fn_header(header, self)
}
fn fold_struct_field(&mut self, sf: StructField) -> StructField {
noop_fold_struct_field(sf, self)
}
fn fold_item_kind(&mut self, i: ItemKind) -> ItemKind {
noop_fold_item_kind(i, self)
}
fn fold_trait_item(&mut self, i: TraitItem) -> SmallVec<[TraitItem; 1]> {
noop_fold_trait_item(i, self)
}
fn fold_impl_item(&mut self, i: ImplItem) -> SmallVec<[ImplItem; 1]> {
noop_fold_impl_item(i, self)
}
fn fold_fn_decl(&mut self, d: P<FnDecl>) -> P<FnDecl> {
noop_fold_fn_decl(d, self)
}
fn fold_asyncness(&mut self, a: IsAsync) -> IsAsync {
noop_fold_asyncness(a, self)
}
fn fold_block(&mut self, b: P<Block>) -> P<Block> {
noop_fold_block(b, self)
}
fn fold_stmt(&mut self, s: Stmt) -> SmallVec<[Stmt; 1]> {
noop_fold_stmt(s, self)
}
fn fold_arm(&mut self, a: Arm) -> Arm {
noop_fold_arm(a, self)
}
fn fold_guard(&mut self, g: Guard) -> Guard {
noop_fold_guard(g, self)
}
fn fold_pat(&mut self, p: P<Pat>) -> P<Pat> {
noop_fold_pat(p, self)
}
fn fold_anon_const(&mut self, c: AnonConst) -> AnonConst {
noop_fold_anon_const(c, self)
}
fn fold_expr(&mut self, e: P<Expr>) -> P<Expr> {
e.map(|e| noop_fold_expr(e, self))
}
fn fold_range_end(&mut self, re: RangeEnd) -> RangeEnd {
noop_fold_range_end(re, self)
}
fn fold_opt_expr(&mut self, e: P<Expr>) -> Option<P<Expr>> {
noop_fold_opt_expr(e, self)
}
fn fold_exprs(&mut self, es: Vec<P<Expr>>) -> Vec<P<Expr>> {
noop_fold_exprs(es, self)
}
fn fold_generic_arg(&mut self, arg: GenericArg) -> GenericArg {
match arg {
GenericArg::Lifetime(lt) => GenericArg::Lifetime(self.fold_lifetime(lt)),
GenericArg::Type(ty) => GenericArg::Type(self.fold_ty(ty)),
}
}
fn fold_ty(&mut self, t: P<Ty>) -> P<Ty> {
noop_fold_ty(t, self)
}
fn fold_lifetime(&mut self, l: Lifetime) -> Lifetime {
noop_fold_lifetime(l, self)
}
fn fold_ty_binding(&mut self, t: TypeBinding) -> TypeBinding {
noop_fold_ty_binding(t, self)
}
fn fold_mod(&mut self, m: Mod) -> Mod {
noop_fold_mod(m, self)
}
fn fold_foreign_mod(&mut self, nm: ForeignMod) -> ForeignMod {
noop_fold_foreign_mod(nm, self)
}
fn fold_global_asm(&mut self, ga: P<GlobalAsm>) -> P<GlobalAsm> {
noop_fold_global_asm(ga, self)
}
fn fold_variant(&mut self, v: Variant) -> Variant {
noop_fold_variant(v, self)
}
fn fold_ident(&mut self, i: Ident) -> Ident {
noop_fold_ident(i, self)
}
fn fold_usize(&mut self, i: usize) -> usize {
noop_fold_usize(i, self)
}
fn fold_path(&mut self, p: Path) -> Path {
noop_fold_path(p, self)
}
fn fold_qpath(&mut self, qs: Option<QSelf>, p: Path) -> (Option<QSelf>, Path) {
noop_fold_qpath(qs, p, self)
}
fn fold_generic_args(&mut self, p: GenericArgs) -> GenericArgs {
noop_fold_generic_args(p, self)
}
fn fold_angle_bracketed_parameter_data(&mut self, p: AngleBracketedArgs)
-> AngleBracketedArgs
{
noop_fold_angle_bracketed_parameter_data(p, self)
}
fn fold_parenthesized_parameter_data(&mut self, p: ParenthesisedArgs)
-> ParenthesisedArgs
{
noop_fold_parenthesized_parameter_data(p, self)
}
fn fold_local(&mut self, l: P<Local>) -> P<Local> {
noop_fold_local(l, self)
}
fn fold_mac(&mut self, _mac: Mac) -> Mac {
panic!("fold_mac disabled by default");
// N.B., see note about macros above.
// if you really want a folder that
// works on macros, use this
// definition in your trait impl:
// fold::noop_fold_mac(_mac, self)
}
fn fold_macro_def(&mut self, def: MacroDef) -> MacroDef {
noop_fold_macro_def(def, self)
}
fn fold_label(&mut self, label: Label) -> Label {
noop_fold_label(label, self)
}
fn fold_attribute(&mut self, at: Attribute) -> Option<Attribute> {
noop_fold_attribute(at, self)
}
fn fold_arg(&mut self, a: Arg) -> Arg {
noop_fold_arg(a, self)
}
fn fold_generics(&mut self, generics: Generics) -> Generics {
noop_fold_generics(generics, self)
}
fn fold_trait_ref(&mut self, p: TraitRef) -> TraitRef {
noop_fold_trait_ref(p, self)
}
fn fold_poly_trait_ref(&mut self, p: PolyTraitRef) -> PolyTraitRef {
noop_fold_poly_trait_ref(p, self)
}
fn fold_variant_data(&mut self, vdata: VariantData) -> VariantData {
noop_fold_variant_data(vdata, self)
}
fn fold_generic_param(&mut self, param: GenericParam) -> GenericParam {
noop_fold_generic_param(param, self)
}
fn fold_generic_params(&mut self, params: Vec<GenericParam>) -> Vec<GenericParam> {
noop_fold_generic_params(params, self)
}
fn fold_tt(&mut self, tt: TokenTree) -> TokenTree {
noop_fold_tt(tt, self)
}
fn fold_tts(&mut self, tts: TokenStream) -> TokenStream {
noop_fold_tts(tts, self)
}
fn fold_token(&mut self, t: token::Token) -> token::Token {
noop_fold_token(t, self)
}
fn fold_interpolated(&mut self, nt: token::Nonterminal) -> token::Nonterminal {
noop_fold_interpolated(nt, self)
}
fn fold_opt_bounds(&mut self, b: Option<GenericBounds>) -> Option<GenericBounds> {
noop_fold_opt_bounds(b, self)
}
fn fold_bounds(&mut self, b: GenericBounds) -> GenericBounds {
noop_fold_bounds(b, self)
}
fn fold_param_bound(&mut self, tpb: GenericBound) -> GenericBound {
noop_fold_param_bound(tpb, self)
}
fn fold_mt(&mut self, mt: MutTy) -> MutTy {
noop_fold_mt(mt, self)
}
fn fold_field(&mut self, field: Field) -> Field {
noop_fold_field(field, self)
}
fn fold_where_clause(&mut self, where_clause: WhereClause)
-> WhereClause {
noop_fold_where_clause(where_clause, self)
}
fn fold_where_predicate(&mut self, where_predicate: WherePredicate)
-> WherePredicate {
noop_fold_where_predicate(where_predicate, self)
}
fn fold_vis(&mut self, vis: Visibility) -> Visibility {
noop_fold_vis(vis, self)
}
fn new_id(&mut self, i: NodeId) -> NodeId {
i
}
fn new_span(&mut self, sp: Span) -> Span {
sp
}
}
pub fn noop_fold_meta_items<T: Folder>(meta_items: Vec<MetaItem>, fld: &mut T) -> Vec<MetaItem> {
meta_items.move_map(|x| fld.fold_meta_item(x))
}
pub fn noop_fold_use_tree<T: Folder>(use_tree: UseTree, fld: &mut T) -> UseTree {
UseTree {
span: fld.new_span(use_tree.span),
prefix: fld.fold_path(use_tree.prefix),
kind: match use_tree.kind {
UseTreeKind::Simple(rename, id1, id2) =>
UseTreeKind::Simple(rename.map(|ident| fld.fold_ident(ident)),
fld.new_id(id1), fld.new_id(id2)),
UseTreeKind::Glob => UseTreeKind::Glob,
UseTreeKind::Nested(items) => UseTreeKind::Nested(items.move_map(|(tree, id)| {
(fld.fold_use_tree(tree), fld.new_id(id))
})),
},
}
}
pub fn fold_attrs<T: Folder>(attrs: Vec<Attribute>, fld: &mut T) -> Vec<Attribute> {
attrs.move_flat_map(|x| fld.fold_attribute(x))
}
pub fn fold_thin_attrs<T: Folder>(attrs: ThinVec<Attribute>, fld: &mut T) -> ThinVec<Attribute> {
fold_attrs(attrs.into(), fld).into()
}
pub fn noop_fold_arm<T: Folder>(Arm {attrs, pats, guard, body}: Arm,
fld: &mut T) -> Arm {
Arm {
attrs: fold_attrs(attrs, fld),
pats: pats.move_map(|x| fld.fold_pat(x)),
guard: guard.map(|x| fld.fold_guard(x)),
body: fld.fold_expr(body),
}
}
pub fn noop_fold_guard<T: Folder>(g: Guard, fld: &mut T) -> Guard {
match g {
Guard::If(e) => Guard::If(fld.fold_expr(e)),
}
}
pub fn noop_fold_ty_binding<T: Folder>(b: TypeBinding, fld: &mut T) -> TypeBinding {
TypeBinding {
id: fld.new_id(b.id),
ident: fld.fold_ident(b.ident),
ty: fld.fold_ty(b.ty),
span: fld.new_span(b.span),
}
}
pub fn noop_fold_ty<T: Folder>(t: P<Ty>, fld: &mut T) -> P<Ty> {
t.map(|Ty {id, node, span}| Ty {
id: fld.new_id(id),
node: match node {
TyKind::Infer | TyKind::ImplicitSelf | TyKind::Err => node,
TyKind::Slice(ty) => TyKind::Slice(fld.fold_ty(ty)),
TyKind::Ptr(mt) => TyKind::Ptr(fld.fold_mt(mt)),
TyKind::Rptr(region, mt) => {
TyKind::Rptr(region.map(|lt| noop_fold_lifetime(lt, fld)), fld.fold_mt(mt))
}
TyKind::BareFn(f) => {
TyKind::BareFn(f.map(|BareFnTy {generic_params, unsafety, abi, decl}| BareFnTy {
generic_params: fld.fold_generic_params(generic_params),
unsafety,
abi,
decl: fld.fold_fn_decl(decl)
}))
}
TyKind::Never => node,
TyKind::Tup(tys) => TyKind::Tup(tys.move_map(|ty| fld.fold_ty(ty))),
TyKind::Paren(ty) => TyKind::Paren(fld.fold_ty(ty)),
TyKind::Path(qself, path) => {
let (qself, path) = fld.fold_qpath(qself, path);
TyKind::Path(qself, path)
}
TyKind::Array(ty, length) => {
TyKind::Array(fld.fold_ty(ty), fld.fold_anon_const(length))
}
TyKind::Typeof(expr) => {
TyKind::Typeof(fld.fold_anon_const(expr))
}
TyKind::TraitObject(bounds, syntax) => {
TyKind::TraitObject(bounds.move_map(|b| fld.fold_param_bound(b)), syntax)
}
TyKind::ImplTrait(id, bounds) => {
TyKind::ImplTrait(fld.new_id(id), bounds.move_map(|b| fld.fold_param_bound(b)))
}
TyKind::Mac(mac) => {
TyKind::Mac(fld.fold_mac(mac))
}
},
span: fld.new_span(span)
})
}
pub fn noop_fold_foreign_mod<T: Folder>(ForeignMod {abi, items}: ForeignMod,
fld: &mut T) -> ForeignMod {
ForeignMod {
abi,
items: items.move_flat_map(|x| fld.fold_foreign_item(x)),
}
}
pub fn noop_fold_global_asm<T: Folder>(ga: P<GlobalAsm>,
_: &mut T) -> P<GlobalAsm> {
ga
}
pub fn noop_fold_variant<T: Folder>(v: Variant, fld: &mut T) -> Variant {
Spanned {
node: Variant_ {
ident: fld.fold_ident(v.node.ident),
attrs: fold_attrs(v.node.attrs, fld),
data: fld.fold_variant_data(v.node.data),
disr_expr: v.node.disr_expr.map(|e| fld.fold_anon_const(e)),
},
span: fld.new_span(v.span),
}
}
pub fn noop_fold_ident<T: Folder>(ident: Ident, fld: &mut T) -> Ident {
Ident::new(ident.name, fld.new_span(ident.span))
}
pub fn noop_fold_usize<T: Folder>(i: usize, _: &mut T) -> usize {
i
}
pub fn noop_fold_path<T: Folder>(Path { segments, span }: Path, fld: &mut T) -> Path {
Path {
segments: segments.move_map(|PathSegment { ident, id, args }| PathSegment {
ident: fld.fold_ident(ident),
id: fld.new_id(id),
args: args.map(|args| args.map(|args| fld.fold_generic_args(args))),
}),
span: fld.new_span(span)
}
}
pub fn noop_fold_qpath<T: Folder>(qself: Option<QSelf>,
path: Path,
fld: &mut T) -> (Option<QSelf>, Path) {
let qself = qself.map(|QSelf { ty, path_span, position }| {
QSelf {
ty: fld.fold_ty(ty),
path_span: fld.new_span(path_span),
position,
}
});
(qself, fld.fold_path(path))
}
pub fn noop_fold_generic_args<T: Folder>(generic_args: GenericArgs, fld: &mut T) -> GenericArgs
{
match generic_args {
GenericArgs::AngleBracketed(data) => {
GenericArgs::AngleBracketed(fld.fold_angle_bracketed_parameter_data(data))
}
GenericArgs::Parenthesized(data) => {
GenericArgs::Parenthesized(fld.fold_parenthesized_parameter_data(data))
}
}
}
pub fn noop_fold_angle_bracketed_parameter_data<T: Folder>(data: AngleBracketedArgs,
fld: &mut T)
-> AngleBracketedArgs
{
let AngleBracketedArgs { args, bindings, span } = data;
AngleBracketedArgs {
args: args.move_map(|arg| fld.fold_generic_arg(arg)),
bindings: bindings.move_map(|b| fld.fold_ty_binding(b)),
span: fld.new_span(span)
}
}
pub fn noop_fold_parenthesized_parameter_data<T: Folder>(data: ParenthesisedArgs,
fld: &mut T)
-> ParenthesisedArgs
{
let ParenthesisedArgs { inputs, output, span } = data;
ParenthesisedArgs {
inputs: inputs.move_map(|ty| fld.fold_ty(ty)),
output: output.map(|ty| fld.fold_ty(ty)),
span: fld.new_span(span)
}
}
pub fn noop_fold_local<T: Folder>(l: P<Local>, fld: &mut T) -> P<Local> {
l.map(|Local {id, pat, ty, init, span, attrs}| Local {
id: fld.new_id(id),
pat: fld.fold_pat(pat),
ty: ty.map(|t| fld.fold_ty(t)),
init: init.map(|e| fld.fold_expr(e)),
span: fld.new_span(span),
attrs: fold_attrs(attrs.into(), fld).into(),
})
}
pub fn noop_fold_attribute<T: Folder>(attr: Attribute, fld: &mut T) -> Option<Attribute> {
Some(Attribute {
id: attr.id,
style: attr.style,
path: fld.fold_path(attr.path),
tokens: fld.fold_tts(attr.tokens),
is_sugared_doc: attr.is_sugared_doc,
span: fld.new_span(attr.span),
})
}
pub fn noop_fold_mac<T: Folder>(Spanned {node, span}: Mac, fld: &mut T) -> Mac {
Spanned {
node: Mac_ {
tts: fld.fold_tts(node.stream()).into(),
path: fld.fold_path(node.path),
delim: node.delim,
},
span: fld.new_span(span)
}
}
pub fn noop_fold_macro_def<T: Folder>(def: MacroDef, fld: &mut T) -> MacroDef {
MacroDef {
tokens: fld.fold_tts(def.tokens.into()).into(),
legacy: def.legacy,
}
}
pub fn noop_fold_meta_list_item<T: Folder>(li: NestedMetaItem, fld: &mut T)
-> NestedMetaItem {
Spanned {
node: match li.node {
NestedMetaItemKind::MetaItem(mi) => {
NestedMetaItemKind::MetaItem(fld.fold_meta_item(mi))
},
NestedMetaItemKind::Literal(lit) => NestedMetaItemKind::Literal(lit)
},
span: fld.new_span(li.span)
}
}
pub fn noop_fold_meta_item<T: Folder>(mi: MetaItem, fld: &mut T) -> MetaItem {
MetaItem {
ident: mi.ident,
node: match mi.node {
MetaItemKind::Word => MetaItemKind::Word,
MetaItemKind::List(mis) => {
MetaItemKind::List(mis.move_map(|e| fld.fold_meta_list_item(e)))
},
MetaItemKind::NameValue(s) => MetaItemKind::NameValue(s),
},
span: fld.new_span(mi.span)
}
}
pub fn noop_fold_arg<T: Folder>(Arg {id, pat, ty}: Arg, fld: &mut T) -> Arg {
Arg {
id: fld.new_id(id),
pat: fld.fold_pat(pat),
ty: fld.fold_ty(ty)
}
}
pub fn noop_fold_tt<T: Folder>(tt: TokenTree, fld: &mut T) -> TokenTree {
match tt {
TokenTree::Token(span, tok) =>
TokenTree::Token(fld.new_span(span), fld.fold_token(tok)),
TokenTree::Delimited(span, delim, tts) => TokenTree::Delimited(
DelimSpan::from_pair(fld.new_span(span.open), fld.new_span(span.close)),
delim,
fld.fold_tts(tts.stream()).into(),
),
}
}
pub fn noop_fold_tts<T: Folder>(tts: TokenStream, fld: &mut T) -> TokenStream {
tts.map(|tt| fld.fold_tt(tt))
}
// apply ident folder if it's an ident, apply other folds to interpolated nodes
pub fn noop_fold_token<T: Folder>(t: token::Token, fld: &mut T) -> token::Token {
match t {
token::Ident(id, is_raw) => token::Ident(fld.fold_ident(id), is_raw),
token::Lifetime(id) => token::Lifetime(fld.fold_ident(id)),
token::Interpolated(nt) => {
let nt = match Lrc::try_unwrap(nt) {
Ok(nt) => nt,
Err(nt) => (*nt).clone(),
};
Token::interpolated(fld.fold_interpolated(nt.0))
}
_ => t
}
}
/// apply folder to elements of interpolated nodes
//
// N.B., this can occur only when applying a fold to partially expanded code, where
// parsed pieces have gotten implanted ito *other* macro invocations. This is relevant
// for macro hygiene, but possibly not elsewhere.
//
// One problem here occurs because the types for fold_item, fold_stmt, etc. allow the
// folder to return *multiple* items; this is a problem for the nodes here, because
// they insist on having exactly one piece. One solution would be to mangle the fold
// trait to include one-to-many and one-to-one versions of these entry points, but that
// would probably confuse a lot of people and help very few. Instead, I'm just going
// to put in dynamic checks. I think the performance impact of this will be pretty much
// nonexistent. The danger is that someone will apply a fold to a partially expanded
// node, and will be confused by the fact that their "fold_item" or "fold_stmt" isn't
// getting called on NtItem or NtStmt nodes. Hopefully they'll wind up reading this
// comment, and doing something appropriate.
//
// BTW, design choice: I considered just changing the type of, e.g., NtItem to contain
// multiple items, but decided against it when I looked at parse_item_or_view_item and
// tried to figure out what I would do with multiple items there....
pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T)
-> token::Nonterminal {
match nt {
token::NtItem(item) =>
token::NtItem(fld.fold_item(item)
// this is probably okay, because the only folds likely
// to peek inside interpolated nodes will be renamings/markings,
// which map single items to single items
.expect_one("expected fold to produce exactly one item")),
token::NtBlock(block) => token::NtBlock(fld.fold_block(block)),
token::NtStmt(stmt) =>
token::NtStmt(fld.fold_stmt(stmt)
// this is probably okay, because the only folds likely
// to peek inside interpolated nodes will be renamings/markings,
// which map single items to single items
.expect_one("expected fold to produce exactly one statement")),
token::NtPat(pat) => token::NtPat(fld.fold_pat(pat)),
token::NtExpr(expr) => token::NtExpr(fld.fold_expr(expr)),
token::NtTy(ty) => token::NtTy(fld.fold_ty(ty)),
token::NtIdent(ident, is_raw) => token::NtIdent(fld.fold_ident(ident), is_raw),
token::NtLifetime(ident) => token::NtLifetime(fld.fold_ident(ident)),
token::NtLiteral(expr) => token::NtLiteral(fld.fold_expr(expr)),
token::NtMeta(meta) => token::NtMeta(fld.fold_meta_item(meta)),
token::NtPath(path) => token::NtPath(fld.fold_path(path)),
token::NtTT(tt) => token::NtTT(fld.fold_tt(tt)),
token::NtArm(arm) => token::NtArm(fld.fold_arm(arm)),
token::NtImplItem(item) =>
token::NtImplItem(fld.fold_impl_item(item)
.expect_one("expected fold to produce exactly one item")),
token::NtTraitItem(item) =>
token::NtTraitItem(fld.fold_trait_item(item)
.expect_one("expected fold to produce exactly one item")),
token::NtGenerics(generics) => token::NtGenerics(fld.fold_generics(generics)),
token::NtWhereClause(where_clause) =>
token::NtWhereClause(fld.fold_where_clause(where_clause)),
token::NtArg(arg) => token::NtArg(fld.fold_arg(arg)),
token::NtVis(vis) => token::NtVis(fld.fold_vis(vis)),
token::NtForeignItem(ni) =>
token::NtForeignItem(fld.fold_foreign_item(ni)
// see reasoning above
.expect_one("expected fold to produce exactly one item")),
}
}
pub fn noop_fold_asyncness<T: Folder>(asyncness: IsAsync, fld: &mut T) -> IsAsync {
match asyncness {
IsAsync::Async { closure_id, return_impl_trait_id } => IsAsync::Async {
closure_id: fld.new_id(closure_id),
return_impl_trait_id: fld.new_id(return_impl_trait_id),
},
IsAsync::NotAsync => IsAsync::NotAsync,
}
}
pub fn noop_fold_fn_decl<T: Folder>(decl: P<FnDecl>, fld: &mut T) -> P<FnDecl> {
decl.map(|FnDecl {inputs, output, variadic}| FnDecl {
inputs: inputs.move_map(|x| fld.fold_arg(x)),
output: match output {
FunctionRetTy::Ty(ty) => FunctionRetTy::Ty(fld.fold_ty(ty)),
FunctionRetTy::Default(span) => FunctionRetTy::Default(fld.new_span(span)),
},
variadic,
})
}
pub fn noop_fold_param_bound<T>(pb: GenericBound, fld: &mut T) -> GenericBound where T: Folder {
match pb {
GenericBound::Trait(ty, modifier) => {
GenericBound::Trait(fld.fold_poly_trait_ref(ty), modifier)
}
GenericBound::Outlives(lifetime) => {
GenericBound::Outlives(noop_fold_lifetime(lifetime, fld))
}
}
}
pub fn noop_fold_generic_param<T: Folder>(param: GenericParam, fld: &mut T) -> GenericParam {
let attrs: Vec<_> = param.attrs.into();
GenericParam {
ident: fld.fold_ident(param.ident),
id: fld.new_id(param.id),
attrs: attrs.into_iter()
.flat_map(|x| fld.fold_attribute(x).into_iter())
.collect::<Vec<_>>()
.into(),
bounds: param.bounds.move_map(|l| noop_fold_param_bound(l, fld)),
kind: match param.kind {
GenericParamKind::Lifetime => GenericParamKind::Lifetime,
GenericParamKind::Type { default } => GenericParamKind::Type {
default: default.map(|ty| fld.fold_ty(ty))
}
}
}
}
pub fn noop_fold_generic_params<T: Folder>(
params: Vec<GenericParam>,
fld: &mut T
) -> Vec<GenericParam> {
params.move_map(|p| fld.fold_generic_param(p))
}
pub fn noop_fold_label<T: Folder>(label: Label, fld: &mut T) -> Label {
Label {
ident: fld.fold_ident(label.ident),
}
}
fn noop_fold_lifetime<T: Folder>(l: Lifetime, fld: &mut T) -> Lifetime {
Lifetime {
id: fld.new_id(l.id),
ident: fld.fold_ident(l.ident),
}
}
pub fn noop_fold_generics<T: Folder>(Generics { params, where_clause, span }: Generics,
fld: &mut T) -> Generics {
Generics {
params: fld.fold_generic_params(params),
where_clause: fld.fold_where_clause(where_clause),
span: fld.new_span(span),
}
}
pub fn noop_fold_where_clause<T: Folder>(
WhereClause {id, predicates, span}: WhereClause,
fld: &mut T)
-> WhereClause {
WhereClause {
id: fld.new_id(id),
predicates: predicates.move_map(|predicate| {
fld.fold_where_predicate(predicate)
}),
span,
}
}
pub fn noop_fold_where_predicate<T: Folder>(
pred: WherePredicate,
fld: &mut T)
-> WherePredicate {
match pred {
ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate{bound_generic_params,
bounded_ty,
bounds,
span}) => {
ast::WherePredicate::BoundPredicate(ast::WhereBoundPredicate {
bound_generic_params: fld.fold_generic_params(bound_generic_params),
bounded_ty: fld.fold_ty(bounded_ty),
bounds: bounds.move_map(|x| fld.fold_param_bound(x)),
span: fld.new_span(span)
})
}
ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate{lifetime,
bounds,
span}) => {
ast::WherePredicate::RegionPredicate(ast::WhereRegionPredicate {
span: fld.new_span(span),
lifetime: noop_fold_lifetime(lifetime, fld),
bounds: bounds.move_map(|bound| noop_fold_param_bound(bound, fld))
})
}
ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{id,
lhs_ty,
rhs_ty,
span}) => {
ast::WherePredicate::EqPredicate(ast::WhereEqPredicate{
id: fld.new_id(id),
lhs_ty: fld.fold_ty(lhs_ty),
rhs_ty: fld.fold_ty(rhs_ty),
span: fld.new_span(span)
})
}
}
}
pub fn noop_fold_variant_data<T: Folder>(vdata: VariantData, fld: &mut T) -> VariantData {
match vdata {
ast::VariantData::Struct(fields, id) => {
ast::VariantData::Struct(fields.move_map(|f| fld.fold_struct_field(f)),
fld.new_id(id))
}
ast::VariantData::Tuple(fields, id) => {
ast::VariantData::Tuple(fields.move_map(|f| fld.fold_struct_field(f)),
fld.new_id(id))
}
ast::VariantData::Unit(id) => ast::VariantData::Unit(fld.new_id(id))
}
}
pub fn noop_fold_trait_ref<T: Folder>(p: TraitRef, fld: &mut T) -> TraitRef {
let id = fld.new_id(p.ref_id);
let TraitRef {
path,
ref_id: _,
} = p;
ast::TraitRef {
path: fld.fold_path(path),
ref_id: id,
}
}
pub fn noop_fold_poly_trait_ref<T: Folder>(p: PolyTraitRef, fld: &mut T) -> PolyTraitRef {
ast::PolyTraitRef {
bound_generic_params: fld.fold_generic_params(p.bound_generic_params),
trait_ref: fld.fold_trait_ref(p.trait_ref),
span: fld.new_span(p.span),
}
}
pub fn noop_fold_struct_field<T: Folder>(f: StructField, fld: &mut T) -> StructField {
StructField {
span: fld.new_span(f.span),
id: fld.new_id(f.id),
ident: f.ident.map(|ident| fld.fold_ident(ident)),
vis: fld.fold_vis(f.vis),
ty: fld.fold_ty(f.ty),
attrs: fold_attrs(f.attrs, fld),
}
}
pub fn noop_fold_field<T: Folder>(f: Field, folder: &mut T) -> Field {
Field {
ident: folder.fold_ident(f.ident),
expr: folder.fold_expr(f.expr),
span: folder.new_span(f.span),
is_shorthand: f.is_shorthand,
attrs: fold_thin_attrs(f.attrs, folder),
}
}
pub fn noop_fold_mt<T: Folder>(MutTy {ty, mutbl}: MutTy, folder: &mut T) -> MutTy {
MutTy {
ty: folder.fold_ty(ty),
mutbl,
}
}
pub fn noop_fold_opt_bounds<T: Folder>(b: Option<GenericBounds>, folder: &mut T)
-> Option<GenericBounds> {
b.map(|bounds| folder.fold_bounds(bounds))
}
fn noop_fold_bounds<T: Folder>(bounds: GenericBounds, folder: &mut T)
-> GenericBounds {
bounds.move_map(|bound| folder.fold_param_bound(bound))
}
pub fn noop_fold_block<T: Folder>(b: P<Block>, folder: &mut T) -> P<Block> {
b.map(|Block {id, stmts, rules, span}| Block {
id: folder.new_id(id),
stmts: stmts.move_flat_map(|s| folder.fold_stmt(s).into_iter()),
rules,
span: folder.new_span(span),
})
}
pub fn noop_fold_item_kind<T: Folder>(i: ItemKind, folder: &mut T) -> ItemKind {
match i {
ItemKind::ExternCrate(orig_name) => ItemKind::ExternCrate(orig_name),
ItemKind::Use(use_tree) => {
ItemKind::Use(use_tree.map(|tree| folder.fold_use_tree(tree)))
}
ItemKind::Static(t, m, e) => {
ItemKind::Static(folder.fold_ty(t), m, folder.fold_expr(e))
}
ItemKind::Const(t, e) => {
ItemKind::Const(folder.fold_ty(t), folder.fold_expr(e))
}
ItemKind::Fn(decl, header, generics, body) => {
let generics = folder.fold_generics(generics);
let header = folder.fold_fn_header(header);
let decl = folder.fold_fn_decl(decl);
let body = folder.fold_block(body);
ItemKind::Fn(decl, header, generics, body)
}
ItemKind::Mod(m) => ItemKind::Mod(folder.fold_mod(m)),
ItemKind::ForeignMod(nm) => ItemKind::ForeignMod(folder.fold_foreign_mod(nm)),
ItemKind::GlobalAsm(ga) => ItemKind::GlobalAsm(folder.fold_global_asm(ga)),
ItemKind::Ty(t, generics) => {
ItemKind::Ty(folder.fold_ty(t), folder.fold_generics(generics))
}
ItemKind::Existential(bounds, generics) => ItemKind::Existential(
folder.fold_bounds(bounds),
folder.fold_generics(generics),
),
ItemKind::Enum(enum_definition, generics) => {
let generics = folder.fold_generics(generics);
let variants = enum_definition.variants.move_map(|x| folder.fold_variant(x));
ItemKind::Enum(ast::EnumDef { variants }, generics)
}
ItemKind::Struct(struct_def, generics) => {
let generics = folder.fold_generics(generics);
ItemKind::Struct(folder.fold_variant_data(struct_def), generics)
}
ItemKind::Union(struct_def, generics) => {
let generics = folder.fold_generics(generics);
ItemKind::Union(folder.fold_variant_data(struct_def), generics)
}
ItemKind::Impl(unsafety,
polarity,
defaultness,
generics,
ifce,
ty,
impl_items) => ItemKind::Impl(
unsafety,
polarity,
defaultness,
folder.fold_generics(generics),
ifce.map(|trait_ref| folder.fold_trait_ref(trait_ref)),
folder.fold_ty(ty),
impl_items.move_flat_map(|item| folder.fold_impl_item(item)),
),
ItemKind::Trait(is_auto, unsafety, generics, bounds, items) => ItemKind::Trait(
is_auto,
unsafety,
folder.fold_generics(generics),
folder.fold_bounds(bounds),
items.move_flat_map(|item| folder.fold_trait_item(item)),
),
ItemKind::TraitAlias(generics, bounds) => ItemKind::TraitAlias(
folder.fold_generics(generics),
folder.fold_bounds(bounds)),
ItemKind::Mac(m) => ItemKind::Mac(folder.fold_mac(m)),
ItemKind::MacroDef(def) => ItemKind::MacroDef(folder.fold_macro_def(def)),
}
}
pub fn noop_fold_trait_item<T: Folder>(i: TraitItem, folder: &mut T) -> SmallVec<[TraitItem; 1]> {
smallvec![TraitItem {
id: folder.new_id(i.id),
ident: folder.fold_ident(i.ident),
attrs: fold_attrs(i.attrs, folder),
generics: folder.fold_generics(i.generics),
node: match i.node {
TraitItemKind::Const(ty, default) => {
TraitItemKind::Const(folder.fold_ty(ty),
default.map(|x| folder.fold_expr(x)))
}
TraitItemKind::Method(sig, body) => {
TraitItemKind::Method(noop_fold_method_sig(sig, folder),
body.map(|x| folder.fold_block(x)))
}
TraitItemKind::Type(bounds, default) => {
TraitItemKind::Type(folder.fold_bounds(bounds),
default.map(|x| folder.fold_ty(x)))
}
ast::TraitItemKind::Macro(mac) => {
TraitItemKind::Macro(folder.fold_mac(mac))
}
},
span: folder.new_span(i.span),
tokens: i.tokens,
}]
}
pub fn noop_fold_impl_item<T: Folder>(i: ImplItem, folder: &mut T)-> SmallVec<[ImplItem; 1]> {
smallvec![ImplItem {
id: folder.new_id(i.id),
vis: folder.fold_vis(i.vis),
ident: folder.fold_ident(i.ident),
attrs: fold_attrs(i.attrs, folder),
generics: folder.fold_generics(i.generics),
defaultness: i.defaultness,
node: match i.node {
ast::ImplItemKind::Const(ty, expr) => {
ast::ImplItemKind::Const(folder.fold_ty(ty), folder.fold_expr(expr))
}
ast::ImplItemKind::Method(sig, body) => {
ast::ImplItemKind::Method(noop_fold_method_sig(sig, folder),
folder.fold_block(body))
}
ast::ImplItemKind::Type(ty) => ast::ImplItemKind::Type(folder.fold_ty(ty)),
ast::ImplItemKind::Existential(bounds) => {
ast::ImplItemKind::Existential(folder.fold_bounds(bounds))
},
ast::ImplItemKind::Macro(mac) => ast::ImplItemKind::Macro(folder.fold_mac(mac))
},
span: folder.new_span(i.span),
tokens: i.tokens,
}]
}
pub fn noop_fold_fn_header<T: Folder>(mut header: FnHeader, folder: &mut T) -> FnHeader {
header.asyncness = folder.fold_asyncness(header.asyncness);
header
}
pub fn noop_fold_mod<T: Folder>(Mod {inner, items, inline}: Mod, folder: &mut T) -> Mod {
Mod {
inner: folder.new_span(inner),
items: items.move_flat_map(|x| folder.fold_item(x)),
inline: inline,
}
}
pub fn noop_fold_crate<T: Folder>(Crate {module, attrs, span}: Crate,
folder: &mut T) -> Crate {
let mut items = folder.fold_item(P(ast::Item {
ident: keywords::Invalid.ident(),
attrs,
id: ast::DUMMY_NODE_ID,
vis: respan(span.shrink_to_lo(), ast::VisibilityKind::Public),
span,
node: ast::ItemKind::Mod(module),
tokens: None,
})).into_iter();
let (module, attrs, span) = match items.next() {
Some(item) => {
assert!(items.next().is_none(),
"a crate cannot expand to more than one item");
item.and_then(|ast::Item { attrs, span, node, .. }| {
match node {
ast::ItemKind::Mod(m) => (m, attrs, span),
_ => panic!("fold converted a module to not a module"),
}
})
}
None => (ast::Mod {
inner: span,
items: vec![],
inline: true,
}, vec![], span)
};
Crate {
module,
attrs,
span,
}
}
// fold one item into possibly many items
pub fn noop_fold_item<T: Folder>(i: P<Item>, folder: &mut T) -> SmallVec<[P<Item>; 1]> {
smallvec![i.map(|i| folder.fold_item_simple(i))]
}
// fold one item into exactly one item
pub fn noop_fold_item_simple<T: Folder>(Item {id, ident, attrs, node, vis, span, tokens}: Item,
folder: &mut T) -> Item {
Item {
id: folder.new_id(id),
vis: folder.fold_vis(vis),
ident: folder.fold_ident(ident),
attrs: fold_attrs(attrs, folder),
node: folder.fold_item_kind(node),
span: folder.new_span(span),
// FIXME: if this is replaced with a call to `folder.fold_tts` it causes
// an ICE during resolve... odd!
tokens,
}
}
pub fn noop_fold_foreign_item<T: Folder>(ni: ForeignItem, folder: &mut T)
-> SmallVec<[ForeignItem; 1]>
{
smallvec![folder.fold_foreign_item_simple(ni)]
}
pub fn noop_fold_foreign_item_simple<T: Folder>(ni: ForeignItem, folder: &mut T) -> ForeignItem {
ForeignItem {
id: folder.new_id(ni.id),
vis: folder.fold_vis(ni.vis),
ident: folder.fold_ident(ni.ident),
attrs: fold_attrs(ni.attrs, folder),
node: match ni.node {
ForeignItemKind::Fn(fdec, generics) => {
ForeignItemKind::Fn(folder.fold_fn_decl(fdec), folder.fold_generics(generics))
}
ForeignItemKind::Static(t, m) => {
ForeignItemKind::Static(folder.fold_ty(t), m)
}
ForeignItemKind::Ty => ForeignItemKind::Ty,
ForeignItemKind::Macro(mac) => ForeignItemKind::Macro(folder.fold_mac(mac)),
},
span: folder.new_span(ni.span)
}
}
pub fn noop_fold_method_sig<T: Folder>(sig: MethodSig, folder: &mut T) -> MethodSig {
MethodSig {
header: folder.fold_fn_header(sig.header),
decl: folder.fold_fn_decl(sig.decl)
}
}
pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> {
p.map(|Pat {id, node, span}| Pat {
id: folder.new_id(id),
node: match node {
PatKind::Wild => PatKind::Wild,
PatKind::Ident(binding_mode, ident, sub) => {
PatKind::Ident(binding_mode,
folder.fold_ident(ident),
sub.map(|x| folder.fold_pat(x)))
}
PatKind::Lit(e) => PatKind::Lit(folder.fold_expr(e)),
PatKind::TupleStruct(pth, pats, ddpos) => {
PatKind::TupleStruct(folder.fold_path(pth),
pats.move_map(|x| folder.fold_pat(x)), ddpos)
}
PatKind::Path(qself, pth) => {
let (qself, pth) = folder.fold_qpath(qself, pth);
PatKind::Path(qself, pth)
}
PatKind::Struct(pth, fields, etc) => {
let pth = folder.fold_path(pth);
let fs = fields.move_map(|f| {
Spanned { span: folder.new_span(f.span),
node: ast::FieldPat {
ident: folder.fold_ident(f.node.ident),
pat: folder.fold_pat(f.node.pat),
is_shorthand: f.node.is_shorthand,
attrs: fold_attrs(f.node.attrs.into(), folder).into()
}}
});
PatKind::Struct(pth, fs, etc)
}
PatKind::Tuple(elts, ddpos) => {
PatKind::Tuple(elts.move_map(|x| folder.fold_pat(x)), ddpos)
}
PatKind::Box(inner) => PatKind::Box(folder.fold_pat(inner)),
PatKind::Ref(inner, mutbl) => PatKind::Ref(folder.fold_pat(inner), mutbl),
PatKind::Range(e1, e2, Spanned { span, node: end }) => {
PatKind::Range(folder.fold_expr(e1),
folder.fold_expr(e2),
Spanned { span, node: folder.fold_range_end(end) })
},
PatKind::Slice(before, slice, after) => {
PatKind::Slice(before.move_map(|x| folder.fold_pat(x)),
slice.map(|x| folder.fold_pat(x)),
after.move_map(|x| folder.fold_pat(x)))
}
PatKind::Paren(inner) => PatKind::Paren(folder.fold_pat(inner)),
PatKind::Mac(mac) => PatKind::Mac(folder.fold_mac(mac))
},
span: folder.new_span(span)
})
}
pub fn noop_fold_range_end<T: Folder>(end: RangeEnd, _folder: &mut T) -> RangeEnd {
end
}
pub fn noop_fold_anon_const<T: Folder>(constant: AnonConst, folder: &mut T) -> AnonConst {
let AnonConst {id, value} = constant;
AnonConst {
id: folder.new_id(id),
value: folder.fold_expr(value),
}
}
pub fn noop_fold_expr<T: Folder>(Expr {id, node, span, attrs}: Expr, folder: &mut T) -> Expr {
Expr {
node: match node {
ExprKind::Box(e) => {
ExprKind::Box(folder.fold_expr(e))
}
ExprKind::ObsoleteInPlace(a, b) => {
ExprKind::ObsoleteInPlace(folder.fold_expr(a), folder.fold_expr(b))
}
ExprKind::Array(exprs) => {
ExprKind::Array(folder.fold_exprs(exprs))
}
ExprKind::Repeat(expr, count) => {
ExprKind::Repeat(folder.fold_expr(expr), folder.fold_anon_const(count))
}
ExprKind::Tup(exprs) => ExprKind::Tup(folder.fold_exprs(exprs)),
ExprKind::Call(f, args) => {
ExprKind::Call(folder.fold_expr(f),
folder.fold_exprs(args))
}
ExprKind::MethodCall(seg, args) => {
ExprKind::MethodCall(
PathSegment {
ident: folder.fold_ident(seg.ident),
id: folder.new_id(seg.id),
args: seg.args.map(|args| {
args.map(|args| folder.fold_generic_args(args))
}),
},
folder.fold_exprs(args))
}
ExprKind::Binary(binop, lhs, rhs) => {
ExprKind::Binary(binop,
folder.fold_expr(lhs),
folder.fold_expr(rhs))
}
ExprKind::Unary(binop, ohs) => {
ExprKind::Unary(binop, folder.fold_expr(ohs))
}
ExprKind::Lit(l) => ExprKind::Lit(l),
ExprKind::Cast(expr, ty) => {
ExprKind::Cast(folder.fold_expr(expr), folder.fold_ty(ty))
}
ExprKind::Type(expr, ty) => {
ExprKind::Type(folder.fold_expr(expr), folder.fold_ty(ty))
}
ExprKind::AddrOf(m, ohs) => ExprKind::AddrOf(m, folder.fold_expr(ohs)),
ExprKind::If(cond, tr, fl) => {
ExprKind::If(folder.fold_expr(cond),
folder.fold_block(tr),
fl.map(|x| folder.fold_expr(x)))
}
ExprKind::IfLet(pats, expr, tr, fl) => {
ExprKind::IfLet(pats.move_map(|pat| folder.fold_pat(pat)),
folder.fold_expr(expr),
folder.fold_block(tr),
fl.map(|x| folder.fold_expr(x)))
}
ExprKind::While(cond, body, opt_label) => {
ExprKind::While(folder.fold_expr(cond),
folder.fold_block(body),
opt_label.map(|label| folder.fold_label(label)))
}
ExprKind::WhileLet(pats, expr, body, opt_label) => {
ExprKind::WhileLet(pats.move_map(|pat| folder.fold_pat(pat)),
folder.fold_expr(expr),
folder.fold_block(body),
opt_label.map(|label| folder.fold_label(label)))
}
ExprKind::ForLoop(pat, iter, body, opt_label) => {
ExprKind::ForLoop(folder.fold_pat(pat),
folder.fold_expr(iter),
folder.fold_block(body),
opt_label.map(|label| folder.fold_label(label)))
}
ExprKind::Loop(body, opt_label) => {
ExprKind::Loop(folder.fold_block(body),
opt_label.map(|label| folder.fold_label(label)))
}
ExprKind::Match(expr, arms) => {
ExprKind::Match(folder.fold_expr(expr),
arms.move_map(|x| folder.fold_arm(x)))
}
ExprKind::Closure(capture_clause, asyncness, movability, decl, body, span) => {
ExprKind::Closure(capture_clause,
folder.fold_asyncness(asyncness),
movability,
folder.fold_fn_decl(decl),
folder.fold_expr(body),
folder.new_span(span))
}
ExprKind::Block(blk, opt_label) => {
ExprKind::Block(folder.fold_block(blk),
opt_label.map(|label| folder.fold_label(label)))
}
ExprKind::Async(capture_clause, node_id, body) => {
ExprKind::Async(
capture_clause,
folder.new_id(node_id),
folder.fold_block(body),
)
}
ExprKind::Assign(el, er) => {
ExprKind::Assign(folder.fold_expr(el), folder.fold_expr(er))
}
ExprKind::AssignOp(op, el, er) => {
ExprKind::AssignOp(op,
folder.fold_expr(el),
folder.fold_expr(er))
}
ExprKind::Field(el, ident) => {
ExprKind::Field(folder.fold_expr(el), folder.fold_ident(ident))
}
ExprKind::Index(el, er) => {
ExprKind::Index(folder.fold_expr(el), folder.fold_expr(er))
}
ExprKind::Range(e1, e2, lim) => {
ExprKind::Range(e1.map(|x| folder.fold_expr(x)),
e2.map(|x| folder.fold_expr(x)),
lim)
}
ExprKind::Path(qself, path) => {
let (qself, path) = folder.fold_qpath(qself, path);
ExprKind::Path(qself, path)
}
ExprKind::Break(opt_label, opt_expr) => {
ExprKind::Break(opt_label.map(|label| folder.fold_label(label)),
opt_expr.map(|e| folder.fold_expr(e)))
}
ExprKind::Continue(opt_label) => {
ExprKind::Continue(opt_label.map(|label| folder.fold_label(label)))
}
ExprKind::Ret(e) => ExprKind::Ret(e.map(|x| folder.fold_expr(x))),
ExprKind::InlineAsm(asm) => ExprKind::InlineAsm(asm.map(|asm| {
InlineAsm {
inputs: asm.inputs.move_map(|(c, input)| {
(c, folder.fold_expr(input))
}),
outputs: asm.outputs.move_map(|out| {
InlineAsmOutput {
constraint: out.constraint,
expr: folder.fold_expr(out.expr),
is_rw: out.is_rw,
is_indirect: out.is_indirect,
}
}),
..asm
}
})),
ExprKind::Mac(mac) => ExprKind::Mac(folder.fold_mac(mac)),
ExprKind::Struct(path, fields, maybe_expr) => {
ExprKind::Struct(folder.fold_path(path),
fields.move_map(|x| folder.fold_field(x)),
maybe_expr.map(|x| folder.fold_expr(x)))
},
ExprKind::Paren(ex) => {
let sub_expr = folder.fold_expr(ex);
return Expr {
// Nodes that are equal modulo `Paren` sugar no-ops should have the same ids.
id: sub_expr.id,
node: ExprKind::Paren(sub_expr),
span: folder.new_span(span),
attrs: fold_attrs(attrs.into(), folder).into(),
};
}
ExprKind::Yield(ex) => ExprKind::Yield(ex.map(|x| folder.fold_expr(x))),
ExprKind::Try(ex) => ExprKind::Try(folder.fold_expr(ex)),
ExprKind::TryBlock(body) => ExprKind::TryBlock(folder.fold_block(body)),
ExprKind::Err => ExprKind::Err,
},
id: folder.new_id(id),
span: folder.new_span(span),
attrs: fold_attrs(attrs.into(), folder).into(),
}
}
pub fn noop_fold_opt_expr<T: Folder>(e: P<Expr>, folder: &mut T) -> Option<P<Expr>> {
Some(folder.fold_expr(e))
}
pub fn noop_fold_exprs<T: Folder>(es: Vec<P<Expr>>, folder: &mut T) -> Vec<P<Expr>> {
es.move_flat_map(|e| folder.fold_opt_expr(e))
}
pub fn noop_fold_stmt<T: Folder>(Stmt {node, span, id}: Stmt, folder: &mut T) -> SmallVec<[Stmt; 1]>
{
let id = folder.new_id(id);
let span = folder.new_span(span);
noop_fold_stmt_kind(node, folder).into_iter().map(|node| {
Stmt { id: id, node: node, span: span }
}).collect()
}
pub fn noop_fold_stmt_kind<T: Folder>(node: StmtKind, folder: &mut T) -> SmallVec<[StmtKind; 1]> {
match node {
StmtKind::Local(local) => smallvec![StmtKind::Local(folder.fold_local(local))],
StmtKind::Item(item) => folder.fold_item(item).into_iter().map(StmtKind::Item).collect(),
StmtKind::Expr(expr) => {
folder.fold_opt_expr(expr).into_iter().map(StmtKind::Expr).collect()
}
StmtKind::Semi(expr) => {
folder.fold_opt_expr(expr).into_iter().map(StmtKind::Semi).collect()
}
StmtKind::Mac(mac) => smallvec![StmtKind::Mac(mac.map(|(mac, semi, attrs)| {
(folder.fold_mac(mac), semi, fold_attrs(attrs.into(), folder).into())
}))],
}
}
pub fn noop_fold_vis<T: Folder>(vis: Visibility, folder: &mut T) -> Visibility {
match vis.node {
VisibilityKind::Restricted { path, id } => {
respan(vis.span, VisibilityKind::Restricted {
path: path.map(|path| folder.fold_path(path)),
id: folder.new_id(id),
})
}
_ => vis,
}
}
#[cfg(test)]
mod tests {
use std::io;
use ast::{self, Ident};
use util::parser_testing::{string_to_crate, matches_codepattern};
use print::pprust;
use fold;
use with_globals;
use super::*;
// this version doesn't care about getting comments or docstrings in.
fn fake_print_crate(s: &mut pprust::State,
krate: &ast::Crate) -> io::Result<()> {
s.print_mod(&krate.module, &krate.attrs)
}
// change every identifier to "zz"
struct ToZzIdentFolder;
impl Folder for ToZzIdentFolder {
fn fold_ident(&mut self, _: ast::Ident) -> ast::Ident {
Ident::from_str("zz")
}
fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
fold::noop_fold_mac(mac, self)
}
}
// maybe add to expand.rs...
macro_rules! assert_pred {
($pred:expr, $predname:expr, $a:expr , $b:expr) => (
{
let pred_val = $pred;
let a_val = $a;
let b_val = $b;
if !(pred_val(&a_val, &b_val)) {
panic!("expected args satisfying {}, got {} and {}",
$predname, a_val, b_val);
}
}
)
}
// make sure idents get transformed everywhere
#[test] fn ident_transformation () {
with_globals(|| {
let mut zz_fold = ToZzIdentFolder;
let ast = string_to_crate(
"#[a] mod b {fn c (d : e, f : g) {h!(i,j,k);l;m}}".to_string());
let folded_crate = zz_fold.fold_crate(ast);
assert_pred!(
matches_codepattern,
"matches_codepattern",
pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
"#[zz]mod zz{fn zz(zz:zz,zz:zz){zz!(zz,zz,zz);zz;zz}}".to_string());
})
}
// even inside macro defs....
#[test] fn ident_transformation_in_defs () {
with_globals(|| {
let mut zz_fold = ToZzIdentFolder;
let ast = string_to_crate(
"macro_rules! a {(b $c:expr $(d $e:token)f+ => \
(g $(d $d $e)+))} ".to_string());
let folded_crate = zz_fold.fold_crate(ast);
assert_pred!(
matches_codepattern,
"matches_codepattern",
pprust::to_string(|s| fake_print_crate(s, &folded_crate)),
"macro_rules! zz((zz$zz:zz$(zz $zz:zz)zz+=>(zz$(zz$zz$zz)+)));".to_string());
})
}
}