pub use self::SyntaxExtension::*;
use ast::{self, Attribute, Name, PatKind, MetaItem};
use attr::HasAttrs;
use codemap::{self, CodeMap, Spanned, respan};
use syntax_pos::{Span, MultiSpan, DUMMY_SP};
use errors::DiagnosticBuilder;
use ext::expand::{self, Expansion, Invocation};
use ext::hygiene::{Mark, SyntaxContext};
use fold::{self, Folder};
use parse::{self, parser, DirectoryOwnership};
use parse::token;
use ptr::P;
use symbol::{keywords, Ident, Symbol};
use util::small_vector::SmallVector;
use std::collections::HashMap;
use std::iter;
use std::path::PathBuf;
use std::rc::Rc;
use rustc_data_structures::sync::Lrc;
use std::default::Default;
use tokenstream::{self, TokenStream};
#[derive(Debug,Clone)]
pub enum Annotatable {
Item(P<ast::Item>),
TraitItem(P<ast::TraitItem>),
ImplItem(P<ast::ImplItem>),
}
impl HasAttrs for Annotatable {
fn attrs(&self) -> &[Attribute] {
match *self {
Annotatable::Item(ref item) => &item.attrs,
Annotatable::TraitItem(ref trait_item) => &trait_item.attrs,
Annotatable::ImplItem(ref impl_item) => &impl_item.attrs,
}
}
fn map_attrs<F: FnOnce(Vec<Attribute>) -> Vec<Attribute>>(self, f: F) -> Self {
match self {
Annotatable::Item(item) => Annotatable::Item(item.map_attrs(f)),
Annotatable::TraitItem(trait_item) => Annotatable::TraitItem(trait_item.map_attrs(f)),
Annotatable::ImplItem(impl_item) => Annotatable::ImplItem(impl_item.map_attrs(f)),
}
}
}
impl Annotatable {
pub fn span(&self) -> Span {
match *self {
Annotatable::Item(ref item) => item.span,
Annotatable::TraitItem(ref trait_item) => trait_item.span,
Annotatable::ImplItem(ref impl_item) => impl_item.span,
}
}
pub fn expect_item(self) -> P<ast::Item> {
match self {
Annotatable::Item(i) => i,
_ => panic!("expected Item")
}
}
pub fn map_item_or<F, G>(self, mut f: F, mut or: G) -> Annotatable
where F: FnMut(P<ast::Item>) -> P<ast::Item>,
G: FnMut(Annotatable) -> Annotatable
{
match self {
Annotatable::Item(i) => Annotatable::Item(f(i)),
_ => or(self)
}
}
pub fn expect_trait_item(self) -> ast::TraitItem {
match self {
Annotatable::TraitItem(i) => i.into_inner(),
_ => panic!("expected Item")
}
}
pub fn expect_impl_item(self) -> ast::ImplItem {
match self {
Annotatable::ImplItem(i) => i.into_inner(),
_ => panic!("expected Item")
}
}
pub fn derive_allowed(&self) -> bool {
match *self {
Annotatable::Item(ref item) => match item.node {
ast::ItemKind::Struct(..) |
ast::ItemKind::Enum(..) |
ast::ItemKind::Union(..) => true,
_ => false,
},
_ => false,
}
}
}
pub trait MultiItemDecorator {
fn expand(&self,
ecx: &mut ExtCtxt,
sp: Span,
meta_item: &ast::MetaItem,
item: &Annotatable,
push: &mut FnMut(Annotatable));
}
impl<F> MultiItemDecorator for F
where F : Fn(&mut ExtCtxt, Span, &ast::MetaItem, &Annotatable, &mut FnMut(Annotatable))
{
fn expand(&self,
ecx: &mut ExtCtxt,
sp: Span,
meta_item: &ast::MetaItem,
item: &Annotatable,
push: &mut FnMut(Annotatable)) {
(*self)(ecx, sp, meta_item, item, push)
}
}
pub trait MultiItemModifier {
fn expand(&self,
ecx: &mut ExtCtxt,
span: Span,
meta_item: &ast::MetaItem,
item: Annotatable)
-> Vec<Annotatable>;
}
impl<F, T> MultiItemModifier for F
where F: Fn(&mut ExtCtxt, Span, &ast::MetaItem, Annotatable) -> T,
T: Into<Vec<Annotatable>>,
{
fn expand(&self,
ecx: &mut ExtCtxt,
span: Span,
meta_item: &ast::MetaItem,
item: Annotatable)
-> Vec<Annotatable> {
(*self)(ecx, span, meta_item, item).into()
}
}
impl Into<Vec<Annotatable>> for Annotatable {
fn into(self) -> Vec<Annotatable> {
vec![self]
}
}
pub trait ProcMacro {
fn expand<'cx>(&self,
ecx: &'cx mut ExtCtxt,
span: Span,
ts: TokenStream)
-> TokenStream;
}
impl<F> ProcMacro for F
where F: Fn(TokenStream) -> TokenStream
{
fn expand<'cx>(&self,
_ecx: &'cx mut ExtCtxt,
_span: Span,
ts: TokenStream)
-> TokenStream {
(*self)(ts)
}
}
pub trait AttrProcMacro {
fn expand<'cx>(&self,
ecx: &'cx mut ExtCtxt,
span: Span,
annotation: TokenStream,
annotated: TokenStream)
-> TokenStream;
}
impl<F> AttrProcMacro for F
where F: Fn(TokenStream, TokenStream) -> TokenStream
{
fn expand<'cx>(&self,
_ecx: &'cx mut ExtCtxt,
_span: Span,
annotation: TokenStream,
annotated: TokenStream)
-> TokenStream {
(*self)(annotation, annotated)
}
}
pub trait TTMacroExpander {
fn expand<'cx>(&self, ecx: &'cx mut ExtCtxt, span: Span, input: TokenStream)
-> Box<MacResult+'cx>;
}
pub type MacroExpanderFn =
for<'cx> fn(&'cx mut ExtCtxt, Span, &[tokenstream::TokenTree])
-> Box<MacResult+'cx>;
impl<F> TTMacroExpander for F
where F: for<'cx> Fn(&'cx mut ExtCtxt, Span, &[tokenstream::TokenTree]) -> Box<MacResult+'cx>
{
fn expand<'cx>(&self, ecx: &'cx mut ExtCtxt, span: Span, input: TokenStream)
-> Box<MacResult+'cx> {
struct AvoidInterpolatedIdents;
impl Folder for AvoidInterpolatedIdents {
fn fold_tt(&mut self, tt: tokenstream::TokenTree) -> tokenstream::TokenTree {
if let tokenstream::TokenTree::Token(_, token::Interpolated(ref nt)) = tt {
if let token::NtIdent(ident, is_raw) = nt.0 {
return tokenstream::TokenTree::Token(ident.span,
token::Ident(ident.node, is_raw));
}
}
fold::noop_fold_tt(tt, self)
}
fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
fold::noop_fold_mac(mac, self)
}
}
let input: Vec<_> =
input.trees().map(|tt| AvoidInterpolatedIdents.fold_tt(tt)).collect();
(*self)(ecx, span, &input)
}
}
pub trait IdentMacroExpander {
fn expand<'cx>(&self,
cx: &'cx mut ExtCtxt,
sp: Span,
ident: ast::Ident,
token_tree: Vec<tokenstream::TokenTree>)
-> Box<MacResult+'cx>;
}
pub type IdentMacroExpanderFn =
for<'cx> fn(&'cx mut ExtCtxt, Span, ast::Ident, Vec<tokenstream::TokenTree>)
-> Box<MacResult+'cx>;
impl<F> IdentMacroExpander for F
where F : for<'cx> Fn(&'cx mut ExtCtxt, Span, ast::Ident,
Vec<tokenstream::TokenTree>) -> Box<MacResult+'cx>
{
fn expand<'cx>(&self,
cx: &'cx mut ExtCtxt,
sp: Span,
ident: ast::Ident,
token_tree: Vec<tokenstream::TokenTree>)
-> Box<MacResult+'cx>
{
(*self)(cx, sp, ident, token_tree)
}
}
macro_rules! make_stmts_default {
($me:expr) => {
$me.make_expr().map(|e| SmallVector::one(ast::Stmt {
id: ast::DUMMY_NODE_ID,
span: e.span,
node: ast::StmtKind::Expr(e),
}))
}
}
pub trait MacResult {
fn make_expr(self: Box<Self>) -> Option<P<ast::Expr>> {
None
}
fn make_items(self: Box<Self>) -> Option<SmallVector<P<ast::Item>>> {
None
}
fn make_impl_items(self: Box<Self>) -> Option<SmallVector<ast::ImplItem>> {
None
}
fn make_trait_items(self: Box<Self>) -> Option<SmallVector<ast::TraitItem>> {
None
}
fn make_pat(self: Box<Self>) -> Option<P<ast::Pat>> {
None
}
fn make_stmts(self: Box<Self>) -> Option<SmallVector<ast::Stmt>> {
make_stmts_default!(self)
}
fn make_ty(self: Box<Self>) -> Option<P<ast::Ty>> {
None
}
}
macro_rules! make_MacEager {
( $( $fld:ident: $t:ty, )* ) => {
#[derive(Default)]
pub struct MacEager {
$(
pub $fld: Option<$t>,
)*
}
impl MacEager {
$(
pub fn $fld(v: $t) -> Box<MacResult> {
Box::new(MacEager {
$fld: Some(v),
..Default::default()
})
}
)*
}
}
}
make_MacEager! {
expr: P<ast::Expr>,
pat: P<ast::Pat>,
items: SmallVector<P<ast::Item>>,
impl_items: SmallVector<ast::ImplItem>,
trait_items: SmallVector<ast::TraitItem>,
stmts: SmallVector<ast::Stmt>,
ty: P<ast::Ty>,
}
impl MacResult for MacEager {
fn make_expr(self: Box<Self>) -> Option<P<ast::Expr>> {
self.expr
}
fn make_items(self: Box<Self>) -> Option<SmallVector<P<ast::Item>>> {
self.items
}
fn make_impl_items(self: Box<Self>) -> Option<SmallVector<ast::ImplItem>> {
self.impl_items
}
fn make_trait_items(self: Box<Self>) -> Option<SmallVector<ast::TraitItem>> {
self.trait_items
}
fn make_stmts(self: Box<Self>) -> Option<SmallVector<ast::Stmt>> {
match self.stmts.as_ref().map_or(0, |s| s.len()) {
0 => make_stmts_default!(self),
_ => self.stmts,
}
}
fn make_pat(self: Box<Self>) -> Option<P<ast::Pat>> {
if let Some(p) = self.pat {
return Some(p);
}
if let Some(e) = self.expr {
if let ast::ExprKind::Lit(_) = e.node {
return Some(P(ast::Pat {
id: ast::DUMMY_NODE_ID,
span: e.span,
node: PatKind::Lit(e),
}));
}
}
None
}
fn make_ty(self: Box<Self>) -> Option<P<ast::Ty>> {
self.ty
}
}
#[derive(Copy, Clone)]
pub struct DummyResult {
expr_only: bool,
span: Span
}
impl DummyResult {
pub fn any(sp: Span) -> Box<MacResult+'static> {
Box::new(DummyResult { expr_only: false, span: sp })
}
pub fn expr(sp: Span) -> Box<MacResult+'static> {
Box::new(DummyResult { expr_only: true, span: sp })
}
pub fn raw_expr(sp: Span) -> P<ast::Expr> {
P(ast::Expr {
id: ast::DUMMY_NODE_ID,
node: ast::ExprKind::Lit(P(codemap::respan(sp, ast::LitKind::Bool(false)))),
span: sp,
attrs: ast::ThinVec::new(),
})
}
pub fn raw_pat(sp: Span) -> ast::Pat {
ast::Pat {
id: ast::DUMMY_NODE_ID,
node: PatKind::Wild,
span: sp,
}
}
pub fn raw_ty(sp: Span) -> P<ast::Ty> {
P(ast::Ty {
id: ast::DUMMY_NODE_ID,
node: ast::TyKind::Infer,
span: sp
})
}
}
impl MacResult for DummyResult {
fn make_expr(self: Box<DummyResult>) -> Option<P<ast::Expr>> {
Some(DummyResult::raw_expr(self.span))
}
fn make_pat(self: Box<DummyResult>) -> Option<P<ast::Pat>> {
Some(P(DummyResult::raw_pat(self.span)))
}
fn make_items(self: Box<DummyResult>) -> Option<SmallVector<P<ast::Item>>> {
if self.expr_only {
None
} else {
Some(SmallVector::new())
}
}
fn make_impl_items(self: Box<DummyResult>) -> Option<SmallVector<ast::ImplItem>> {
if self.expr_only {
None
} else {
Some(SmallVector::new())
}
}
fn make_trait_items(self: Box<DummyResult>) -> Option<SmallVector<ast::TraitItem>> {
if self.expr_only {
None
} else {
Some(SmallVector::new())
}
}
fn make_stmts(self: Box<DummyResult>) -> Option<SmallVector<ast::Stmt>> {
Some(SmallVector::one(ast::Stmt {
id: ast::DUMMY_NODE_ID,
node: ast::StmtKind::Expr(DummyResult::raw_expr(self.span)),
span: self.span,
}))
}
fn make_ty(self: Box<DummyResult>) -> Option<P<ast::Ty>> {
Some(DummyResult::raw_ty(self.span))
}
}
pub type BuiltinDeriveFn =
for<'cx> fn(&'cx mut ExtCtxt, Span, &MetaItem, &Annotatable, &mut FnMut(Annotatable));
#[derive(Clone, Copy, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
pub enum MacroKind {
Bang,
Attr,
Derive,
}
pub enum SyntaxExtension {
MultiDecorator(Box<MultiItemDecorator>),
MultiModifier(Box<MultiItemModifier>),
ProcMacro(Box<ProcMacro>),
AttrProcMacro(Box<AttrProcMacro>),
NormalTT {
expander: Box<TTMacroExpander>,
def_info: Option<(ast::NodeId, Span)>,
allow_internal_unstable: bool,
allow_internal_unsafe: bool,
unstable_feature: Option<(Symbol, u32)>,
},
IdentTT(Box<IdentMacroExpander>, Option<Span>, bool),
ProcMacroDerive(Box<MultiItemModifier>, Vec<Symbol> ),
BuiltinDerive(BuiltinDeriveFn),
DeclMacro(Box<TTMacroExpander>, Option<(ast::NodeId, Span)>),
}
impl SyntaxExtension {
pub fn kind(&self) -> MacroKind {
match *self {
SyntaxExtension::DeclMacro(..) |
SyntaxExtension::NormalTT { .. } |
SyntaxExtension::IdentTT(..) |
SyntaxExtension::ProcMacro(..) =>
MacroKind::Bang,
SyntaxExtension::MultiDecorator(..) |
SyntaxExtension::MultiModifier(..) |
SyntaxExtension::AttrProcMacro(..) =>
MacroKind::Attr,
SyntaxExtension::ProcMacroDerive(..) |
SyntaxExtension::BuiltinDerive(..) =>
MacroKind::Derive,
}
}
pub fn is_modern(&self) -> bool {
match *self {
SyntaxExtension::DeclMacro(..) |
SyntaxExtension::ProcMacro(..) |
SyntaxExtension::AttrProcMacro(..) |
SyntaxExtension::ProcMacroDerive(..) => true,
_ => false,
}
}
}
pub type NamedSyntaxExtension = (Name, SyntaxExtension);
pub trait Resolver {
fn next_node_id(&mut self) -> ast::NodeId;
fn get_module_scope(&mut self, id: ast::NodeId) -> Mark;
fn eliminate_crate_var(&mut self, item: P<ast::Item>) -> P<ast::Item>;
fn is_whitelisted_legacy_custom_derive(&self, name: Name) -> bool;
fn visit_expansion(&mut self, mark: Mark, expansion: &Expansion, derives: &[Mark]);
fn add_builtin(&mut self, ident: ast::Ident, ext: Lrc<SyntaxExtension>);
fn resolve_imports(&mut self);
fn find_legacy_attr_invoc(&mut self, attrs: &mut Vec<Attribute>) -> Option<Attribute>;
fn resolve_invoc(&mut self, invoc: &mut Invocation, scope: Mark, force: bool)
-> Result<Option<Lrc<SyntaxExtension>>, Determinacy>;
fn resolve_macro(&mut self, scope: Mark, path: &ast::Path, kind: MacroKind, force: bool)
-> Result<Lrc<SyntaxExtension>, Determinacy>;
fn check_unused_macros(&self);
}
#[derive(Copy, Clone, Debug, PartialEq)]
pub enum Determinacy {
Determined,
Undetermined,
}
pub struct DummyResolver;
impl Resolver for DummyResolver {
fn next_node_id(&mut self) -> ast::NodeId { ast::DUMMY_NODE_ID }
fn get_module_scope(&mut self, _id: ast::NodeId) -> Mark { Mark::root() }
fn eliminate_crate_var(&mut self, item: P<ast::Item>) -> P<ast::Item> { item }
fn is_whitelisted_legacy_custom_derive(&self, _name: Name) -> bool { false }
fn visit_expansion(&mut self, _invoc: Mark, _expansion: &Expansion, _derives: &[Mark]) {}
fn add_builtin(&mut self, _ident: ast::Ident, _ext: Lrc<SyntaxExtension>) {}
fn resolve_imports(&mut self) {}
fn find_legacy_attr_invoc(&mut self, _attrs: &mut Vec<Attribute>) -> Option<Attribute> { None }
fn resolve_invoc(&mut self, _invoc: &mut Invocation, _scope: Mark, _force: bool)
-> Result<Option<Lrc<SyntaxExtension>>, Determinacy> {
Err(Determinacy::Determined)
}
fn resolve_macro(&mut self, _scope: Mark, _path: &ast::Path, _kind: MacroKind,
_force: bool) -> Result<Lrc<SyntaxExtension>, Determinacy> {
Err(Determinacy::Determined)
}
fn check_unused_macros(&self) {}
}
#[derive(Clone)]
pub struct ModuleData {
pub mod_path: Vec<ast::Ident>,
pub directory: PathBuf,
}
#[derive(Clone)]
pub struct ExpansionData {
pub mark: Mark,
pub depth: usize,
pub module: Rc<ModuleData>,
pub directory_ownership: DirectoryOwnership,
pub crate_span: Option<Span>,
}
pub struct ExtCtxt<'a> {
pub parse_sess: &'a parse::ParseSess,
pub ecfg: expand::ExpansionConfig<'a>,
pub root_path: PathBuf,
pub resolver: &'a mut Resolver,
pub resolve_err_count: usize,
pub current_expansion: ExpansionData,
pub expansions: HashMap<Span, Vec<String>>,
}
impl<'a> ExtCtxt<'a> {
pub fn new(parse_sess: &'a parse::ParseSess,
ecfg: expand::ExpansionConfig<'a>,
resolver: &'a mut Resolver)
-> ExtCtxt<'a> {
ExtCtxt {
parse_sess,
ecfg,
root_path: PathBuf::new(),
resolver,
resolve_err_count: 0,
current_expansion: ExpansionData {
mark: Mark::root(),
depth: 0,
module: Rc::new(ModuleData { mod_path: Vec::new(), directory: PathBuf::new() }),
directory_ownership: DirectoryOwnership::Owned { relative: None },
crate_span: None,
},
expansions: HashMap::new(),
}
}
pub fn expander<'b>(&'b mut self) -> expand::MacroExpander<'b, 'a> {
expand::MacroExpander::new(self, false)
}
pub fn monotonic_expander<'b>(&'b mut self) -> expand::MacroExpander<'b, 'a> {
expand::MacroExpander::new(self, true)
}
pub fn new_parser_from_tts(&self, tts: &[tokenstream::TokenTree]) -> parser::Parser<'a> {
parse::stream_to_parser(self.parse_sess, tts.iter().cloned().collect())
}
pub fn codemap(&self) -> &'a CodeMap { self.parse_sess.codemap() }
pub fn parse_sess(&self) -> &'a parse::ParseSess { self.parse_sess }
pub fn cfg(&self) -> &ast::CrateConfig { &self.parse_sess.config }
pub fn call_site(&self) -> Span {
match self.current_expansion.mark.expn_info() {
Some(expn_info) => expn_info.call_site,
None => DUMMY_SP,
}
}
pub fn backtrace(&self) -> SyntaxContext {
SyntaxContext::empty().apply_mark(self.current_expansion.mark)
}
pub fn expansion_cause(&self) -> Option<Span> {
let mut ctxt = self.backtrace();
let mut last_macro = None;
loop {
if ctxt.outer().expn_info().map_or(None, |info| {
if info.callee.name() == "include" {
return None;
}
ctxt = info.call_site.ctxt();
last_macro = Some(info.call_site);
Some(())
}).is_none() {
break
}
}
last_macro
}
pub fn struct_span_warn<S: Into<MultiSpan>>(&self,
sp: S,
msg: &str)
-> DiagnosticBuilder<'a> {
self.parse_sess.span_diagnostic.struct_span_warn(sp, msg)
}
pub fn struct_span_err<S: Into<MultiSpan>>(&self,
sp: S,
msg: &str)
-> DiagnosticBuilder<'a> {
self.parse_sess.span_diagnostic.struct_span_err(sp, msg)
}
pub fn struct_span_fatal<S: Into<MultiSpan>>(&self,
sp: S,
msg: &str)
-> DiagnosticBuilder<'a> {
self.parse_sess.span_diagnostic.struct_span_fatal(sp, msg)
}
pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
self.parse_sess.span_diagnostic.span_fatal(sp, msg).raise();
}
pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
self.parse_sess.span_diagnostic.span_err(sp, msg);
}
pub fn mut_span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str)
-> DiagnosticBuilder<'a> {
self.parse_sess.span_diagnostic.mut_span_err(sp, msg)
}
pub fn span_warn<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
self.parse_sess.span_diagnostic.span_warn(sp, msg);
}
pub fn span_unimpl<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
self.parse_sess.span_diagnostic.span_unimpl(sp, msg);
}
pub fn span_bug<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
self.parse_sess.span_diagnostic.span_bug(sp, msg);
}
pub fn trace_macros_diag(&mut self) {
for (sp, notes) in self.expansions.iter() {
let mut db = self.parse_sess.span_diagnostic.span_note_diag(*sp, "trace_macro");
for note in notes {
db.note(note);
}
db.emit();
}
self.expansions.clear();
}
pub fn bug(&self, msg: &str) -> ! {
self.parse_sess.span_diagnostic.bug(msg);
}
pub fn trace_macros(&self) -> bool {
self.ecfg.trace_mac
}
pub fn set_trace_macros(&mut self, x: bool) {
self.ecfg.trace_mac = x
}
pub fn ident_of(&self, st: &str) -> ast::Ident {
ast::Ident::from_str(st)
}
pub fn std_path(&self, components: &[&str]) -> Vec<ast::Ident> {
let def_site = SyntaxContext::empty().apply_mark(self.current_expansion.mark);
iter::once(Ident { ctxt: def_site, ..keywords::DollarCrate.ident() })
.chain(components.iter().map(|s| self.ident_of(s)))
.collect()
}
pub fn name_of(&self, st: &str) -> ast::Name {
Symbol::intern(st)
}
pub fn check_unused_macros(&self) {
self.resolver.check_unused_macros();
}
}
pub fn expr_to_spanned_string(cx: &mut ExtCtxt, expr: P<ast::Expr>, err_msg: &str)
-> Option<Spanned<(Symbol, ast::StrStyle)>> {
let expr = expr.map(|mut expr| {
expr.span = expr.span.with_ctxt(expr.span.ctxt().apply_mark(cx.current_expansion.mark));
expr
});
let expr = cx.expander().fold_expr(expr);
match expr.node {
ast::ExprKind::Lit(ref l) => match l.node {
ast::LitKind::Str(s, style) => return Some(respan(expr.span, (s, style))),
_ => cx.span_err(l.span, err_msg)
},
_ => cx.span_err(expr.span, err_msg)
}
None
}
pub fn expr_to_string(cx: &mut ExtCtxt, expr: P<ast::Expr>, err_msg: &str)
-> Option<(Symbol, ast::StrStyle)> {
expr_to_spanned_string(cx, expr, err_msg).map(|s| s.node)
}
pub fn check_zero_tts(cx: &ExtCtxt,
sp: Span,
tts: &[tokenstream::TokenTree],
name: &str) {
if !tts.is_empty() {
cx.span_err(sp, &format!("{} takes no arguments", name));
}
}
pub fn get_single_str_from_tts(cx: &mut ExtCtxt,
sp: Span,
tts: &[tokenstream::TokenTree],
name: &str)
-> Option<String> {
let mut p = cx.new_parser_from_tts(tts);
if p.token == token::Eof {
cx.span_err(sp, &format!("{} takes 1 argument", name));
return None
}
let ret = panictry!(p.parse_expr());
let _ = p.eat(&token::Comma);
if p.token != token::Eof {
cx.span_err(sp, &format!("{} takes 1 argument", name));
}
expr_to_string(cx, ret, "argument must be a string literal").map(|(s, _)| {
s.to_string()
})
}
pub fn get_exprs_from_tts(cx: &mut ExtCtxt,
sp: Span,
tts: &[tokenstream::TokenTree]) -> Option<Vec<P<ast::Expr>>> {
let mut p = cx.new_parser_from_tts(tts);
let mut es = Vec::new();
while p.token != token::Eof {
es.push(cx.expander().fold_expr(panictry!(p.parse_expr())));
if p.eat(&token::Comma) {
continue;
}
if p.token != token::Eof {
cx.span_err(sp, "expected token: `,`");
return None;
}
}
Some(es)
}