use ast::{self, Block, Ident, NodeId, PatKind, Path};
use ast::{MacStmtStyle, StmtKind, ItemKind};
use attr::{self, HasAttrs};
use codemap::{ExpnInfo, MacroBang, MacroAttribute, dummy_spanned, respan};
use config::{is_test_or_bench, StripUnconfigured};
use errors::{Applicability, FatalError};
use ext::base::*;
use ext::derive::{add_derived_markers, collect_derives};
use ext::hygiene::{self, Mark, SyntaxContext};
use ext::placeholders::{placeholder, PlaceholderExpander};
use feature_gate::{self, Features, GateIssue, is_builtin_attr, emit_feature_err};
use fold;
use fold::*;
use parse::{DirectoryOwnership, PResult, ParseSess};
use parse::token::{self, Token};
use parse::parser::Parser;
use ptr::P;
use symbol::Symbol;
use symbol::keywords;
use syntax_pos::{Span, DUMMY_SP, FileName};
use syntax_pos::hygiene::ExpnFormat;
use tokenstream::{TokenStream, TokenTree};
use util::small_vector::SmallVector;
use visit::{self, Visitor};
use std::collections::HashMap;
use std::fs::File;
use std::io::Read;
use std::mem;
use std::rc::Rc;
use std::path::PathBuf;
macro_rules! ast_fragments {
(
$($Kind:ident($AstTy:ty) {
$kind_name:expr;
$(one fn $fold_ast:ident; fn $visit_ast:ident;)?
$(many fn $fold_ast_elt:ident; fn $visit_ast_elt:ident;)?
fn $make_ast:ident;
})*
) => {
pub enum AstFragment {
OptExpr(Option<P<ast::Expr>>),
$($Kind($AstTy),)*
}
#[derive(Copy, Clone, PartialEq, Eq)]
pub enum AstFragmentKind {
OptExpr,
$($Kind,)*
}
impl AstFragmentKind {
pub fn name(self) -> &'static str {
match self {
AstFragmentKind::OptExpr => "expression",
$(AstFragmentKind::$Kind => $kind_name,)*
}
}
fn make_from<'a>(self, result: Box<MacResult + 'a>) -> Option<AstFragment> {
match self {
AstFragmentKind::OptExpr =>
result.make_expr().map(Some).map(AstFragment::OptExpr),
$(AstFragmentKind::$Kind => result.$make_ast().map(AstFragment::$Kind),)*
}
}
}
impl AstFragment {
pub fn make_opt_expr(self) -> Option<P<ast::Expr>> {
match self {
AstFragment::OptExpr(expr) => expr,
_ => panic!("AstFragment::make_* called on the wrong kind of fragment"),
}
}
$(pub fn $make_ast(self) -> $AstTy {
match self {
AstFragment::$Kind(ast) => ast,
_ => panic!("AstFragment::make_* called on the wrong kind of fragment"),
}
})*
pub fn fold_with<F: Folder>(self, folder: &mut F) -> Self {
match self {
AstFragment::OptExpr(expr) =>
AstFragment::OptExpr(expr.and_then(|expr| folder.fold_opt_expr(expr))),
$($(AstFragment::$Kind(ast) =>
AstFragment::$Kind(folder.$fold_ast(ast)),)?)*
$($(AstFragment::$Kind(ast) =>
AstFragment::$Kind(ast.into_iter()
.flat_map(|ast| folder.$fold_ast_elt(ast))
.collect()),)?)*
}
}
pub fn visit_with<'a, V: Visitor<'a>>(&'a self, visitor: &mut V) {
match *self {
AstFragment::OptExpr(Some(ref expr)) => visitor.visit_expr(expr),
AstFragment::OptExpr(None) => {}
$($(AstFragment::$Kind(ref ast) => visitor.$visit_ast(ast),)?)*
$($(AstFragment::$Kind(ref ast) => for ast_elt in &ast[..] {
visitor.$visit_ast_elt(ast_elt);
})?)*
}
}
}
impl<'a, 'b> Folder for MacroExpander<'a, 'b> {
fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
self.expand_fragment(AstFragment::OptExpr(Some(expr))).make_opt_expr()
}
$($(fn $fold_ast(&mut self, ast: $AstTy) -> $AstTy {
self.expand_fragment(AstFragment::$Kind(ast)).$make_ast()
})?)*
$($(fn $fold_ast_elt(&mut self, ast_elt: <$AstTy as IntoIterator>::Item) -> $AstTy {
self.expand_fragment(AstFragment::$Kind(SmallVector::one(ast_elt))).$make_ast()
})?)*
}
impl<'a> MacResult for ::ext::tt::macro_rules::ParserAnyMacro<'a> {
$(fn $make_ast(self: Box<::ext::tt::macro_rules::ParserAnyMacro<'a>>)
-> Option<$AstTy> {
Some(self.make(AstFragmentKind::$Kind).$make_ast())
})*
}
}
}
ast_fragments! {
Expr(P<ast::Expr>) { "expression"; one fn fold_expr; fn visit_expr; fn make_expr; }
Pat(P<ast::Pat>) { "pattern"; one fn fold_pat; fn visit_pat; fn make_pat; }
Ty(P<ast::Ty>) { "type"; one fn fold_ty; fn visit_ty; fn make_ty; }
Stmts(SmallVector<ast::Stmt>) { "statement"; many fn fold_stmt; fn visit_stmt; fn make_stmts; }
Items(SmallVector<P<ast::Item>>) { "item"; many fn fold_item; fn visit_item; fn make_items; }
TraitItems(SmallVector<ast::TraitItem>) {
"trait item"; many fn fold_trait_item; fn visit_trait_item; fn make_trait_items;
}
ImplItems(SmallVector<ast::ImplItem>) {
"impl item"; many fn fold_impl_item; fn visit_impl_item; fn make_impl_items;
}
ForeignItems(SmallVector<ast::ForeignItem>) {
"foreign item"; many fn fold_foreign_item; fn visit_foreign_item; fn make_foreign_items;
}
}
impl AstFragmentKind {
fn dummy(self, span: Span) -> Option<AstFragment> {
self.make_from(DummyResult::any(span))
}
fn expect_from_annotatables<I: IntoIterator<Item = Annotatable>>(self, items: I)
-> AstFragment {
let mut items = items.into_iter();
match self {
AstFragmentKind::Items =>
AstFragment::Items(items.map(Annotatable::expect_item).collect()),
AstFragmentKind::ImplItems =>
AstFragment::ImplItems(items.map(Annotatable::expect_impl_item).collect()),
AstFragmentKind::TraitItems =>
AstFragment::TraitItems(items.map(Annotatable::expect_trait_item).collect()),
AstFragmentKind::ForeignItems =>
AstFragment::ForeignItems(items.map(Annotatable::expect_foreign_item).collect()),
AstFragmentKind::Stmts =>
AstFragment::Stmts(items.map(Annotatable::expect_stmt).collect()),
AstFragmentKind::Expr => AstFragment::Expr(
items.next().expect("expected exactly one expression").expect_expr()
),
AstFragmentKind::OptExpr =>
AstFragment::OptExpr(items.next().map(Annotatable::expect_expr)),
AstFragmentKind::Pat | AstFragmentKind::Ty =>
panic!("patterns and types aren't annotatable"),
}
}
}
fn macro_bang_format(path: &ast::Path) -> ExpnFormat {
let mut path_str = String::with_capacity(64);
for (i, segment) in path.segments.iter().enumerate() {
if i != 0 {
path_str.push_str("::");
}
if segment.ident.name != keywords::CrateRoot.name() &&
segment.ident.name != keywords::DollarCrate.name()
{
path_str.push_str(&segment.ident.as_str())
}
}
MacroBang(Symbol::intern(&path_str))
}
pub struct Invocation {
pub kind: InvocationKind,
fragment_kind: AstFragmentKind,
pub expansion_data: ExpansionData,
}
pub enum InvocationKind {
Bang {
mac: ast::Mac,
ident: Option<Ident>,
span: Span,
},
Attr {
attr: Option<ast::Attribute>,
traits: Vec<Path>,
item: Annotatable,
},
Derive {
path: Path,
item: Annotatable,
},
}
impl Invocation {
fn span(&self) -> Span {
match self.kind {
InvocationKind::Bang { span, .. } => span,
InvocationKind::Attr { attr: Some(ref attr), .. } => attr.span,
InvocationKind::Attr { attr: None, .. } => DUMMY_SP,
InvocationKind::Derive { ref path, .. } => path.span,
}
}
}
pub struct MacroExpander<'a, 'b:'a> {
pub cx: &'a mut ExtCtxt<'b>,
monotonic: bool, }
impl<'a, 'b> MacroExpander<'a, 'b> {
pub fn new(cx: &'a mut ExtCtxt<'b>, monotonic: bool) -> Self {
MacroExpander { cx: cx, monotonic: monotonic }
}
pub fn expand_crate(&mut self, mut krate: ast::Crate) -> ast::Crate {
let mut module = ModuleData {
mod_path: vec![Ident::from_str(&self.cx.ecfg.crate_name)],
directory: match self.cx.codemap().span_to_unmapped_path(krate.span) {
FileName::Real(path) => path,
other => PathBuf::from(other.to_string()),
},
};
module.directory.pop();
self.cx.root_path = module.directory.clone();
self.cx.current_expansion.module = Rc::new(module);
self.cx.current_expansion.crate_span = Some(krate.span);
let orig_mod_span = krate.module.inner;
let krate_item = AstFragment::Items(SmallVector::one(P(ast::Item {
attrs: krate.attrs,
span: krate.span,
node: ast::ItemKind::Mod(krate.module),
ident: keywords::Invalid.ident(),
id: ast::DUMMY_NODE_ID,
vis: respan(krate.span.shrink_to_lo(), ast::VisibilityKind::Public),
tokens: None,
})));
match self.expand_fragment(krate_item).make_items().pop().map(P::into_inner) {
Some(ast::Item { attrs, node: ast::ItemKind::Mod(module), .. }) => {
krate.attrs = attrs;
krate.module = module;
},
None => {
krate.attrs = vec![];
krate.module = ast::Mod {
inner: orig_mod_span,
items: vec![],
};
},
_ => unreachable!(),
};
self.cx.trace_macros_diag();
krate
}
fn expand_fragment(&mut self, input_fragment: AstFragment) -> AstFragment {
let orig_expansion_data = self.cx.current_expansion.clone();
self.cx.current_expansion.depth = 0;
let (fragment_with_placeholders, mut invocations)
= self.collect_invocations(input_fragment, &[]);
self.resolve_imports();
invocations.reverse();
let mut expanded_fragments = Vec::new();
let mut derives = HashMap::new();
let mut undetermined_invocations = Vec::new();
let (mut progress, mut force) = (false, !self.monotonic);
loop {
let mut invoc = if let Some(invoc) = invocations.pop() {
invoc
} else {
self.resolve_imports();
if undetermined_invocations.is_empty() { break }
invocations = mem::replace(&mut undetermined_invocations, Vec::new());
force = !mem::replace(&mut progress, false);
continue
};
let scope =
if self.monotonic { invoc.expansion_data.mark } else { orig_expansion_data.mark };
let ext = match self.cx.resolver.resolve_invoc(&mut invoc, scope, force) {
Ok(ext) => Some(ext),
Err(Determinacy::Determined) => None,
Err(Determinacy::Undetermined) => {
undetermined_invocations.push(invoc);
continue
}
};
progress = true;
let ExpansionData { depth, mark, .. } = invoc.expansion_data;
self.cx.current_expansion = invoc.expansion_data.clone();
self.cx.current_expansion.mark = scope;
let (expanded_fragment, new_invocations) = if let Some(ext) = ext {
if let Some(ext) = ext {
let dummy = invoc.fragment_kind.dummy(invoc.span()).unwrap();
let fragment = self.expand_invoc(invoc, &*ext).unwrap_or(dummy);
self.collect_invocations(fragment, &[])
} else if let InvocationKind::Attr { attr: None, traits, item } = invoc.kind {
if !item.derive_allowed() {
let attr = attr::find_by_name(item.attrs(), "derive")
.expect("`derive` attribute should exist");
let span = attr.span;
let mut err = self.cx.mut_span_err(span,
"`derive` may only be applied to \
structs, enums and unions");
if let ast::AttrStyle::Inner = attr.style {
let trait_list = traits.iter()
.map(|t| format!("{}", t)).collect::<Vec<_>>();
let suggestion = format!("#[derive({})]", trait_list.join(", "));
err.span_suggestion_with_applicability(
span, "try an outer attribute", suggestion,
Applicability::MaybeIncorrect
);
}
err.emit();
}
let item = self.fully_configure(item)
.map_attrs(|mut attrs| { attrs.retain(|a| a.path != "derive"); attrs });
let item_with_markers =
add_derived_markers(&mut self.cx, item.span(), &traits, item.clone());
let derives = derives.entry(invoc.expansion_data.mark).or_insert_with(Vec::new);
for path in &traits {
let mark = Mark::fresh(self.cx.current_expansion.mark);
derives.push(mark);
let item = match self.cx.resolver.resolve_macro(
Mark::root(), path, MacroKind::Derive, false) {
Ok(ext) => match *ext {
BuiltinDerive(..) => item_with_markers.clone(),
_ => item.clone(),
},
_ => item.clone(),
};
invocations.push(Invocation {
kind: InvocationKind::Derive { path: path.clone(), item: item },
fragment_kind: invoc.fragment_kind,
expansion_data: ExpansionData {
mark,
..invoc.expansion_data.clone()
},
});
}
let fragment = invoc.fragment_kind
.expect_from_annotatables(::std::iter::once(item_with_markers));
self.collect_invocations(fragment, derives)
} else {
unreachable!()
}
} else {
self.collect_invocations(invoc.fragment_kind.dummy(invoc.span()).unwrap(), &[])
};
if expanded_fragments.len() < depth {
expanded_fragments.push(Vec::new());
}
expanded_fragments[depth - 1].push((mark, expanded_fragment));
if !self.cx.ecfg.single_step {
invocations.extend(new_invocations.into_iter().rev());
}
}
self.cx.current_expansion = orig_expansion_data;
let mut placeholder_expander = PlaceholderExpander::new(self.cx, self.monotonic);
while let Some(expanded_fragments) = expanded_fragments.pop() {
for (mark, expanded_fragment) in expanded_fragments.into_iter().rev() {
let derives = derives.remove(&mark).unwrap_or_else(Vec::new);
placeholder_expander.add(NodeId::placeholder_from_mark(mark),
expanded_fragment, derives);
}
}
fragment_with_placeholders.fold_with(&mut placeholder_expander)
}
fn resolve_imports(&mut self) {
if self.monotonic {
let err_count = self.cx.parse_sess.span_diagnostic.err_count();
self.cx.resolver.resolve_imports();
self.cx.resolve_err_count += self.cx.parse_sess.span_diagnostic.err_count() - err_count;
}
}
fn collect_invocations(&mut self, fragment: AstFragment, derives: &[Mark])
-> (AstFragment, Vec<Invocation>) {
let (fragment_with_placeholders, invocations) = {
let mut collector = InvocationCollector {
cfg: StripUnconfigured {
should_test: self.cx.ecfg.should_test,
sess: self.cx.parse_sess,
features: self.cx.ecfg.features,
},
cx: self.cx,
invocations: Vec::new(),
monotonic: self.monotonic,
};
(fragment.fold_with(&mut collector), collector.invocations)
};
if self.monotonic {
let err_count = self.cx.parse_sess.span_diagnostic.err_count();
let mark = self.cx.current_expansion.mark;
self.cx.resolver.visit_ast_fragment_with_placeholders(mark, &fragment_with_placeholders,
derives);
self.cx.resolve_err_count += self.cx.parse_sess.span_diagnostic.err_count() - err_count;
}
(fragment_with_placeholders, invocations)
}
fn fully_configure(&mut self, item: Annotatable) -> Annotatable {
let mut cfg = StripUnconfigured {
should_test: self.cx.ecfg.should_test,
sess: self.cx.parse_sess,
features: self.cx.ecfg.features,
};
match item {
Annotatable::Item(item) => {
Annotatable::Item(cfg.fold_item(item).pop().unwrap())
}
Annotatable::TraitItem(item) => {
Annotatable::TraitItem(item.map(|item| cfg.fold_trait_item(item).pop().unwrap()))
}
Annotatable::ImplItem(item) => {
Annotatable::ImplItem(item.map(|item| cfg.fold_impl_item(item).pop().unwrap()))
}
Annotatable::ForeignItem(item) => {
Annotatable::ForeignItem(
item.map(|item| cfg.fold_foreign_item(item).pop().unwrap())
)
}
Annotatable::Stmt(stmt) => {
Annotatable::Stmt(stmt.map(|stmt| cfg.fold_stmt(stmt).pop().unwrap()))
}
Annotatable::Expr(expr) => {
Annotatable::Expr(cfg.fold_expr(expr))
}
}
}
fn expand_invoc(&mut self, invoc: Invocation, ext: &SyntaxExtension) -> Option<AstFragment> {
let result = match invoc.kind {
InvocationKind::Bang { .. } => self.expand_bang_invoc(invoc, ext)?,
InvocationKind::Attr { .. } => self.expand_attr_invoc(invoc, ext)?,
InvocationKind::Derive { .. } => self.expand_derive_invoc(invoc, ext)?,
};
if self.cx.current_expansion.depth > self.cx.ecfg.recursion_limit {
let info = self.cx.current_expansion.mark.expn_info().unwrap();
let suggested_limit = self.cx.ecfg.recursion_limit * 2;
let mut err = self.cx.struct_span_err(info.call_site,
&format!("recursion limit reached while expanding the macro `{}`",
info.format.name()));
err.help(&format!(
"consider adding a `#![recursion_limit=\"{}\"]` attribute to your crate",
suggested_limit));
err.emit();
self.cx.trace_macros_diag();
FatalError.raise();
}
Some(result)
}
fn expand_attr_invoc(&mut self,
invoc: Invocation,
ext: &SyntaxExtension)
-> Option<AstFragment> {
let (attr, item) = match invoc.kind {
InvocationKind::Attr { attr, item, .. } => (attr?, item),
_ => unreachable!(),
};
attr::mark_used(&attr);
invoc.expansion_data.mark.set_expn_info(ExpnInfo {
call_site: attr.span,
def_site: None,
format: MacroAttribute(Symbol::intern(&format!("{}", attr.path))),
allow_internal_unstable: false,
allow_internal_unsafe: false,
local_inner_macros: false,
edition: ext.edition(),
});
match *ext {
MultiModifier(ref mac) => {
let meta = attr.parse_meta(self.cx.parse_sess)
.map_err(|mut e| { e.emit(); }).ok()?;
let item = mac.expand(self.cx, attr.span, &meta, item);
Some(invoc.fragment_kind.expect_from_annotatables(item))
}
MultiDecorator(ref mac) => {
let mut items = Vec::new();
let meta = attr.parse_meta(self.cx.parse_sess)
.expect("derive meta should already have been parsed");
mac.expand(self.cx, attr.span, &meta, &item, &mut |item| items.push(item));
items.push(item);
Some(invoc.fragment_kind.expect_from_annotatables(items))
}
AttrProcMacro(ref mac, ..) => {
self.gate_proc_macro_attr_item(attr.span, &item);
let item_tok = TokenTree::Token(DUMMY_SP, Token::interpolated(match item {
Annotatable::Item(item) => token::NtItem(item),
Annotatable::TraitItem(item) => token::NtTraitItem(item.into_inner()),
Annotatable::ImplItem(item) => token::NtImplItem(item.into_inner()),
Annotatable::ForeignItem(item) => token::NtForeignItem(item.into_inner()),
Annotatable::Stmt(stmt) => token::NtStmt(stmt.into_inner()),
Annotatable::Expr(expr) => token::NtExpr(expr),
})).into();
let input = self.extract_proc_macro_attr_input(attr.tokens, attr.span);
let tok_result = mac.expand(self.cx, attr.span, input, item_tok);
let res = self.parse_ast_fragment(tok_result, invoc.fragment_kind,
&attr.path, attr.span);
self.gate_proc_macro_expansion(attr.span, &res);
res
}
ProcMacroDerive(..) | BuiltinDerive(..) => {
self.cx.span_err(attr.span, &format!("`{}` is a derive mode", attr.path));
self.cx.trace_macros_diag();
invoc.fragment_kind.dummy(attr.span)
}
_ => {
let msg = &format!("macro `{}` may not be used in attributes", attr.path);
self.cx.span_err(attr.span, msg);
self.cx.trace_macros_diag();
invoc.fragment_kind.dummy(attr.span)
}
}
}
fn extract_proc_macro_attr_input(&self, tokens: TokenStream, span: Span) -> TokenStream {
let mut trees = tokens.trees();
match trees.next() {
Some(TokenTree::Delimited(_, delim)) => {
if trees.next().is_none() {
return delim.tts.into()
}
}
Some(TokenTree::Token(..)) => {}
None => return TokenStream::empty(),
}
self.cx.span_err(span, "custom attribute invocations must be \
of the form #[foo] or #[foo(..)], the macro name must only be \
followed by a delimiter token");
TokenStream::empty()
}
fn gate_proc_macro_attr_item(&self, span: Span, item: &Annotatable) {
let (kind, gate) = match *item {
Annotatable::Item(ref item) => {
match item.node {
ItemKind::Mod(_) if self.cx.ecfg.proc_macro_mod() => return,
ItemKind::Mod(_) => ("modules", "proc_macro_mod"),
_ => return,
}
}
Annotatable::TraitItem(_) => return,
Annotatable::ImplItem(_) => return,
Annotatable::ForeignItem(_) => return,
Annotatable::Stmt(_) |
Annotatable::Expr(_) if self.cx.ecfg.proc_macro_expr() => return,
Annotatable::Stmt(_) => ("statements", "proc_macro_expr"),
Annotatable::Expr(_) => ("expressions", "proc_macro_expr"),
};
emit_feature_err(
self.cx.parse_sess,
gate,
span,
GateIssue::Language,
&format!("custom attributes cannot be applied to {}", kind),
);
}
fn gate_proc_macro_expansion(&self, span: Span, fragment: &Option<AstFragment>) {
if self.cx.ecfg.proc_macro_gen() {
return
}
let fragment = match fragment {
Some(fragment) => fragment,
None => return,
};
fragment.visit_with(&mut DisallowModules {
span,
parse_sess: self.cx.parse_sess,
});
struct DisallowModules<'a> {
span: Span,
parse_sess: &'a ParseSess,
}
impl<'ast, 'a> Visitor<'ast> for DisallowModules<'a> {
fn visit_item(&mut self, i: &'ast ast::Item) {
let name = match i.node {
ast::ItemKind::Mod(_) => Some("modules"),
ast::ItemKind::MacroDef(_) => Some("macro definitions"),
_ => None,
};
if let Some(name) = name {
emit_feature_err(
self.parse_sess,
"proc_macro_gen",
self.span,
GateIssue::Language,
&format!("procedural macros cannot expand to {}", name),
);
}
visit::walk_item(self, i);
}
fn visit_mac(&mut self, _mac: &'ast ast::Mac) {
}
}
}
fn expand_bang_invoc(&mut self,
invoc: Invocation,
ext: &SyntaxExtension)
-> Option<AstFragment> {
let (mark, kind) = (invoc.expansion_data.mark, invoc.fragment_kind);
let (mac, ident, span) = match invoc.kind {
InvocationKind::Bang { mac, ident, span } => (mac, ident, span),
_ => unreachable!(),
};
let path = &mac.node.path;
let ident = ident.unwrap_or_else(|| keywords::Invalid.ident());
let validate_and_set_expn_info = |this: &mut Self, // arg instead of capture
def_site_span: Option<Span>,
allow_internal_unstable,
allow_internal_unsafe,
local_inner_macros,
unstable_feature: Option<(Symbol, u32)>,
edition| {
if let Some((feature, issue)) = unstable_feature {
let crate_span = this.cx.current_expansion.crate_span.unwrap();
if def_site_span.map_or(false, |def_span| !crate_span.contains(def_span))
&& !span.allows_unstable() && this.cx.ecfg.features.map_or(true, |feats| {
!feats.declared_lib_features.iter().any(|&(feat, _)| feat == feature)
}) {
let explain = format!("macro {}! is unstable", path);
emit_feature_err(this.cx.parse_sess, &*feature.as_str(), span,
GateIssue::Library(Some(issue)), &explain);
this.cx.trace_macros_diag();
return Err(kind.dummy(span));
}
}
if ident.name != keywords::Invalid.name() {
let msg = format!("macro {}! expects no ident argument, given '{}'", path, ident);
this.cx.span_err(path.span, &msg);
this.cx.trace_macros_diag();
return Err(kind.dummy(span));
}
mark.set_expn_info(ExpnInfo {
call_site: span,
def_site: def_site_span,
format: macro_bang_format(path),
allow_internal_unstable,
allow_internal_unsafe,
local_inner_macros,
edition,
});
Ok(())
};
let opt_expanded = match *ext {
DeclMacro(ref expand, def_span, edition) => {
if let Err(dummy_span) = validate_and_set_expn_info(self, def_span.map(|(_, s)| s),
false, false, false, None,
edition) {
dummy_span
} else {
kind.make_from(expand.expand(self.cx, span, mac.node.stream()))
}
}
NormalTT {
ref expander,
def_info,
allow_internal_unstable,
allow_internal_unsafe,
local_inner_macros,
unstable_feature,
edition,
} => {
if let Err(dummy_span) = validate_and_set_expn_info(self, def_info.map(|(_, s)| s),
allow_internal_unstable,
allow_internal_unsafe,
local_inner_macros,
unstable_feature,
edition) {
dummy_span
} else {
kind.make_from(expander.expand(self.cx, span, mac.node.stream()))
}
}
IdentTT(ref expander, tt_span, allow_internal_unstable) => {
if ident.name == keywords::Invalid.name() {
self.cx.span_err(path.span,
&format!("macro {}! expects an ident argument", path));
self.cx.trace_macros_diag();
kind.dummy(span)
} else {
invoc.expansion_data.mark.set_expn_info(ExpnInfo {
call_site: span,
def_site: tt_span,
format: macro_bang_format(path),
allow_internal_unstable,
allow_internal_unsafe: false,
local_inner_macros: false,
edition: hygiene::default_edition(),
});
let input: Vec<_> = mac.node.stream().into_trees().collect();
kind.make_from(expander.expand(self.cx, span, ident, input))
}
}
MultiDecorator(..) | MultiModifier(..) | AttrProcMacro(..) => {
self.cx.span_err(path.span,
&format!("`{}` can only be used in attributes", path));
self.cx.trace_macros_diag();
kind.dummy(span)
}
ProcMacroDerive(..) | BuiltinDerive(..) => {
self.cx.span_err(path.span, &format!("`{}` is a derive mode", path));
self.cx.trace_macros_diag();
kind.dummy(span)
}
ProcMacro(ref expandfun, allow_internal_unstable, edition) => {
if ident.name != keywords::Invalid.name() {
let msg =
format!("macro {}! expects no ident argument, given '{}'", path, ident);
self.cx.span_err(path.span, &msg);
self.cx.trace_macros_diag();
kind.dummy(span)
} else {
self.gate_proc_macro_expansion_kind(span, kind);
invoc.expansion_data.mark.set_expn_info(ExpnInfo {
call_site: span,
def_site: None,
format: macro_bang_format(path),
allow_internal_unstable,
allow_internal_unsafe: false,
local_inner_macros: false,
edition,
});
let tok_result = expandfun.expand(self.cx, span, mac.node.stream());
let result = self.parse_ast_fragment(tok_result, kind, path, span);
self.gate_proc_macro_expansion(span, &result);
result
}
}
};
if opt_expanded.is_some() {
opt_expanded
} else {
let msg = format!("non-{kind} macro in {kind} position: {name}",
name = path.segments[0].ident.name, kind = kind.name());
self.cx.span_err(path.span, &msg);
self.cx.trace_macros_diag();
kind.dummy(span)
}
}
fn gate_proc_macro_expansion_kind(&self, span: Span, kind: AstFragmentKind) {
let kind = match kind {
AstFragmentKind::Expr => "expressions",
AstFragmentKind::OptExpr => "expressions",
AstFragmentKind::Pat => "patterns",
AstFragmentKind::Ty => "types",
AstFragmentKind::Stmts => "statements",
AstFragmentKind::Items => return,
AstFragmentKind::TraitItems => return,
AstFragmentKind::ImplItems => return,
AstFragmentKind::ForeignItems => return,
};
if self.cx.ecfg.proc_macro_non_items() {
return
}
emit_feature_err(
self.cx.parse_sess,
"proc_macro_non_items",
span,
GateIssue::Language,
&format!("procedural macros cannot be expanded to {}", kind),
);
}
fn expand_derive_invoc(&mut self,
invoc: Invocation,
ext: &SyntaxExtension)
-> Option<AstFragment> {
let (path, item) = match invoc.kind {
InvocationKind::Derive { path, item } => (path, item),
_ => unreachable!(),
};
if !item.derive_allowed() {
return None;
}
let pretty_name = Symbol::intern(&format!("derive({})", path));
let span = path.span;
let attr = ast::Attribute {
path, span,
tokens: TokenStream::empty(),
id: ast::AttrId(0), style: ast::AttrStyle::Outer, is_sugared_doc: false,
};
let mut expn_info = ExpnInfo {
call_site: span,
def_site: None,
format: MacroAttribute(pretty_name),
allow_internal_unstable: false,
allow_internal_unsafe: false,
local_inner_macros: false,
edition: ext.edition(),
};
match *ext {
ProcMacroDerive(ref ext, ..) => {
invoc.expansion_data.mark.set_expn_info(expn_info);
let span = span.with_ctxt(self.cx.backtrace());
let dummy = ast::MetaItem { ident: Path::from_ident(keywords::Invalid.ident()),
span: DUMMY_SP,
node: ast::MetaItemKind::Word,
};
let items = ext.expand(self.cx, span, &dummy, item);
Some(invoc.fragment_kind.expect_from_annotatables(items))
}
BuiltinDerive(func) => {
expn_info.allow_internal_unstable = true;
invoc.expansion_data.mark.set_expn_info(expn_info);
let span = span.with_ctxt(self.cx.backtrace());
let mut items = Vec::new();
func(self.cx, span, &attr.meta()?, &item, &mut |a| items.push(a));
Some(invoc.fragment_kind.expect_from_annotatables(items))
}
_ => {
let msg = &format!("macro `{}` may not be used for derive attributes", attr.path);
self.cx.span_err(span, msg);
self.cx.trace_macros_diag();
invoc.fragment_kind.dummy(span)
}
}
}
fn parse_ast_fragment(&mut self,
toks: TokenStream,
kind: AstFragmentKind,
path: &Path,
span: Span)
-> Option<AstFragment> {
let mut parser = self.cx.new_parser_from_tts(&toks.into_trees().collect::<Vec<_>>());
match parser.parse_ast_fragment(kind, false) {
Ok(fragment) => {
parser.ensure_complete_parse(path, kind.name(), span);
Some(fragment)
}
Err(mut err) => {
err.set_span(span);
err.emit();
self.cx.trace_macros_diag();
kind.dummy(span)
}
}
}
}
impl<'a> Parser<'a> {
pub fn parse_ast_fragment(&mut self, kind: AstFragmentKind, macro_legacy_warnings: bool)
-> PResult<'a, AstFragment> {
Ok(match kind {
AstFragmentKind::Items => {
let mut items = SmallVector::new();
while let Some(item) = self.parse_item()? {
items.push(item);
}
AstFragment::Items(items)
}
AstFragmentKind::TraitItems => {
let mut items = SmallVector::new();
while self.token != token::Eof {
items.push(self.parse_trait_item(&mut false)?);
}
AstFragment::TraitItems(items)
}
AstFragmentKind::ImplItems => {
let mut items = SmallVector::new();
while self.token != token::Eof {
items.push(self.parse_impl_item(&mut false)?);
}
AstFragment::ImplItems(items)
}
AstFragmentKind::ForeignItems => {
let mut items = SmallVector::new();
while self.token != token::Eof {
if let Some(item) = self.parse_foreign_item()? {
items.push(item);
}
}
AstFragment::ForeignItems(items)
}
AstFragmentKind::Stmts => {
let mut stmts = SmallVector::new();
while self.token != token::Eof &&
self.token != token::CloseDelim(token::Brace) {
if let Some(stmt) = self.parse_full_stmt(macro_legacy_warnings)? {
stmts.push(stmt);
}
}
AstFragment::Stmts(stmts)
}
AstFragmentKind::Expr => AstFragment::Expr(self.parse_expr()?),
AstFragmentKind::OptExpr => {
if self.token != token::Eof {
AstFragment::OptExpr(Some(self.parse_expr()?))
} else {
AstFragment::OptExpr(None)
}
},
AstFragmentKind::Ty => AstFragment::Ty(self.parse_ty()?),
AstFragmentKind::Pat => AstFragment::Pat(self.parse_pat()?),
})
}
pub fn ensure_complete_parse(&mut self, macro_path: &Path, kind_name: &str, span: Span) {
if self.token != token::Eof {
let msg = format!("macro expansion ignores token `{}` and any following",
self.this_token_to_string());
let def_site_span = self.span.with_ctxt(SyntaxContext::empty());
let mut err = self.diagnostic().struct_span_err(def_site_span, &msg);
let msg = format!("caused by the macro expansion here; the usage \
of `{}!` is likely invalid in {} context",
macro_path, kind_name);
err.span_note(span, &msg).emit();
}
}
}
struct InvocationCollector<'a, 'b: 'a> {
cx: &'a mut ExtCtxt<'b>,
cfg: StripUnconfigured<'a>,
invocations: Vec<Invocation>,
monotonic: bool,
}
impl<'a, 'b> InvocationCollector<'a, 'b> {
fn collect(&mut self, fragment_kind: AstFragmentKind, kind: InvocationKind) -> AstFragment {
let mark = Mark::fresh(self.cx.current_expansion.mark);
self.invocations.push(Invocation {
kind,
fragment_kind,
expansion_data: ExpansionData {
mark,
depth: self.cx.current_expansion.depth + 1,
..self.cx.current_expansion.clone()
},
});
placeholder(fragment_kind, NodeId::placeholder_from_mark(mark))
}
fn collect_bang(&mut self, mac: ast::Mac, span: Span, kind: AstFragmentKind) -> AstFragment {
self.collect(kind, InvocationKind::Bang { mac: mac, ident: None, span: span })
}
fn collect_attr(&mut self,
attr: Option<ast::Attribute>,
traits: Vec<Path>,
item: Annotatable,
kind: AstFragmentKind)
-> AstFragment {
self.collect(kind, InvocationKind::Attr { attr, traits, item })
}
fn classify_item<T>(&mut self, mut item: T) -> (Option<ast::Attribute>, Vec<Path>, T)
where T: HasAttrs,
{
let (mut attr, mut traits) = (None, Vec::new());
item = item.map_attrs(|mut attrs| {
if let Some(legacy_attr_invoc) = self.cx.resolver.find_legacy_attr_invoc(&mut attrs,
true) {
attr = Some(legacy_attr_invoc);
return attrs;
}
if self.cx.ecfg.proc_macro_enabled() {
attr = find_attr_invoc(&mut attrs);
}
traits = collect_derives(&mut self.cx, &mut attrs);
attrs
});
(attr, traits, item)
}
fn classify_nonitem<T: HasAttrs>(&mut self, mut item: T) -> (Option<ast::Attribute>, T) {
let mut attr = None;
item = item.map_attrs(|mut attrs| {
if let Some(legacy_attr_invoc) = self.cx.resolver.find_legacy_attr_invoc(&mut attrs,
false) {
attr = Some(legacy_attr_invoc);
return attrs;
}
if self.cx.ecfg.proc_macro_enabled() {
attr = find_attr_invoc(&mut attrs);
}
attrs
});
(attr, item)
}
fn configure<T: HasAttrs>(&mut self, node: T) -> Option<T> {
self.cfg.configure(node)
}
fn check_attributes(&mut self, attrs: &[ast::Attribute]) {
let features = self.cx.ecfg.features.unwrap();
for attr in attrs.iter() {
self.check_attribute_inner(attr, features);
if attr.path == "derive" {
self.cx.struct_span_warn(attr.span, "`#[derive]` does nothing on macro invocations")
.note("this may become a hard error in a future release")
.emit();
}
}
}
fn check_attribute(&mut self, at: &ast::Attribute) {
let features = self.cx.ecfg.features.unwrap();
self.check_attribute_inner(at, features);
}
fn check_attribute_inner(&mut self, at: &ast::Attribute, features: &Features) {
feature_gate::check_attribute(at, self.cx.parse_sess, features);
}
}
pub fn find_attr_invoc(attrs: &mut Vec<ast::Attribute>) -> Option<ast::Attribute> {
attrs.iter()
.position(|a| !attr::is_known(a) && !is_builtin_attr(a))
.map(|i| attrs.remove(i))
}
impl<'a, 'b> Folder for InvocationCollector<'a, 'b> {
fn fold_expr(&mut self, expr: P<ast::Expr>) -> P<ast::Expr> {
let mut expr = self.cfg.configure_expr(expr).into_inner();
expr.node = self.cfg.configure_expr_kind(expr.node);
let (attr, expr) = self.classify_nonitem(expr);
if attr.is_some() {
attr.as_ref().map(|a| self.cfg.maybe_emit_expr_attr_err(a));
return self.collect_attr(attr, vec![], Annotatable::Expr(P(expr)),
AstFragmentKind::Expr).make_expr();
}
if let ast::ExprKind::Mac(mac) = expr.node {
self.check_attributes(&expr.attrs);
self.collect_bang(mac, expr.span, AstFragmentKind::Expr).make_expr()
} else {
P(noop_fold_expr(expr, self))
}
}
fn fold_opt_expr(&mut self, expr: P<ast::Expr>) -> Option<P<ast::Expr>> {
let mut expr = configure!(self, expr).into_inner();
expr.node = self.cfg.configure_expr_kind(expr.node);
let (attr, expr) = self.classify_nonitem(expr);
if attr.is_some() {
attr.as_ref().map(|a| self.cfg.maybe_emit_expr_attr_err(a));
return self.collect_attr(attr, vec![], Annotatable::Expr(P(expr)),
AstFragmentKind::OptExpr)
.make_opt_expr();
}
if let ast::ExprKind::Mac(mac) = expr.node {
self.check_attributes(&expr.attrs);
self.collect_bang(mac, expr.span, AstFragmentKind::OptExpr).make_opt_expr()
} else {
Some(P(noop_fold_expr(expr, self)))
}
}
fn fold_pat(&mut self, pat: P<ast::Pat>) -> P<ast::Pat> {
let pat = self.cfg.configure_pat(pat);
match pat.node {
PatKind::Mac(_) => {}
_ => return noop_fold_pat(pat, self),
}
pat.and_then(|pat| match pat.node {
PatKind::Mac(mac) => self.collect_bang(mac, pat.span, AstFragmentKind::Pat).make_pat(),
_ => unreachable!(),
})
}
fn fold_stmt(&mut self, stmt: ast::Stmt) -> SmallVector<ast::Stmt> {
let mut stmt = match self.cfg.configure_stmt(stmt) {
Some(stmt) => stmt,
None => return SmallVector::new(),
};
if !stmt.is_expr() {
let (attr, derives, stmt_) = if stmt.is_item() {
self.classify_item(stmt)
} else {
let (attr, stmt) = self.classify_nonitem(stmt);
(attr, vec![], stmt)
};
if attr.is_some() || !derives.is_empty() {
return self.collect_attr(attr, derives,
Annotatable::Stmt(P(stmt_)), AstFragmentKind::Stmts)
.make_stmts();
}
stmt = stmt_;
}
if let StmtKind::Mac(mac) = stmt.node {
let (mac, style, attrs) = mac.into_inner();
self.check_attributes(&attrs);
let mut placeholder = self.collect_bang(mac, stmt.span, AstFragmentKind::Stmts)
.make_stmts();
if style == MacStmtStyle::Semicolon {
if let Some(stmt) = placeholder.pop() {
placeholder.push(stmt.add_trailing_semicolon());
}
}
return placeholder;
}
let ast::Stmt { id, node, span } = stmt;
noop_fold_stmt_kind(node, self).into_iter().map(|node| {
ast::Stmt { id, node, span }
}).collect()
}
fn fold_block(&mut self, block: P<Block>) -> P<Block> {
let old_directory_ownership = self.cx.current_expansion.directory_ownership;
self.cx.current_expansion.directory_ownership = DirectoryOwnership::UnownedViaBlock;
let result = noop_fold_block(block, self);
self.cx.current_expansion.directory_ownership = old_directory_ownership;
result
}
fn fold_item(&mut self, item: P<ast::Item>) -> SmallVector<P<ast::Item>> {
let item = configure!(self, item);
let (attr, traits, mut item) = self.classify_item(item);
if attr.is_some() || !traits.is_empty() {
let item = Annotatable::Item(item);
return self.collect_attr(attr, traits, item, AstFragmentKind::Items).make_items();
}
match item.node {
ast::ItemKind::Mac(..) => {
self.check_attributes(&item.attrs);
item.and_then(|item| match item.node {
ItemKind::Mac(mac) => {
self.collect(AstFragmentKind::Items, InvocationKind::Bang {
mac,
ident: Some(item.ident),
span: item.span,
}).make_items()
}
_ => unreachable!(),
})
}
ast::ItemKind::Mod(ast::Mod { inner, .. }) => {
if item.ident == keywords::Invalid.ident() {
return noop_fold_item(item, self);
}
let orig_directory_ownership = self.cx.current_expansion.directory_ownership;
let mut module = (*self.cx.current_expansion.module).clone();
module.mod_path.push(item.ident);
let inline_module = item.span.contains(inner) || inner == DUMMY_SP;
if inline_module {
if let Some(path) = attr::first_attr_value_str_by_name(&item.attrs, "path") {
self.cx.current_expansion.directory_ownership =
DirectoryOwnership::Owned { relative: None };
module.directory.push(&*path.as_str());
} else {
module.directory.push(&*item.ident.as_str());
}
} else {
let path = self.cx.parse_sess.codemap().span_to_unmapped_path(inner);
let mut path = match path {
FileName::Real(path) => path,
other => PathBuf::from(other.to_string()),
};
let directory_ownership = match path.file_name().unwrap().to_str() {
Some("mod.rs") => DirectoryOwnership::Owned { relative: None },
Some(_) => DirectoryOwnership::Owned {
relative: Some(item.ident),
},
None => DirectoryOwnership::UnownedViaMod(false),
};
path.pop();
module.directory = path;
self.cx.current_expansion.directory_ownership = directory_ownership;
}
let orig_module =
mem::replace(&mut self.cx.current_expansion.module, Rc::new(module));
let result = noop_fold_item(item, self);
self.cx.current_expansion.module = orig_module;
self.cx.current_expansion.directory_ownership = orig_directory_ownership;
result
}
ast::ItemKind::Fn(..) if self.cx.ecfg.should_test => {
if item.attrs.iter().any(|attr| is_test_or_bench(attr)) {
item = item.map(|mut item| {
item.vis = respan(item.vis.span, ast::VisibilityKind::Public);
item
});
}
noop_fold_item(item, self)
}
_ => noop_fold_item(item, self),
}
}
fn fold_trait_item(&mut self, item: ast::TraitItem) -> SmallVector<ast::TraitItem> {
let item = configure!(self, item);
let (attr, traits, item) = self.classify_item(item);
if attr.is_some() || !traits.is_empty() {
let item = Annotatable::TraitItem(P(item));
return self.collect_attr(attr, traits, item, AstFragmentKind::TraitItems)
.make_trait_items()
}
match item.node {
ast::TraitItemKind::Macro(mac) => {
let ast::TraitItem { attrs, span, .. } = item;
self.check_attributes(&attrs);
self.collect_bang(mac, span, AstFragmentKind::TraitItems).make_trait_items()
}
_ => fold::noop_fold_trait_item(item, self),
}
}
fn fold_impl_item(&mut self, item: ast::ImplItem) -> SmallVector<ast::ImplItem> {
let item = configure!(self, item);
let (attr, traits, item) = self.classify_item(item);
if attr.is_some() || !traits.is_empty() {
let item = Annotatable::ImplItem(P(item));
return self.collect_attr(attr, traits, item, AstFragmentKind::ImplItems)
.make_impl_items();
}
match item.node {
ast::ImplItemKind::Macro(mac) => {
let ast::ImplItem { attrs, span, .. } = item;
self.check_attributes(&attrs);
self.collect_bang(mac, span, AstFragmentKind::ImplItems).make_impl_items()
}
_ => fold::noop_fold_impl_item(item, self),
}
}
fn fold_ty(&mut self, ty: P<ast::Ty>) -> P<ast::Ty> {
let ty = match ty.node {
ast::TyKind::Mac(_) => ty.into_inner(),
_ => return fold::noop_fold_ty(ty, self),
};
match ty.node {
ast::TyKind::Mac(mac) => self.collect_bang(mac, ty.span, AstFragmentKind::Ty).make_ty(),
_ => unreachable!(),
}
}
fn fold_foreign_mod(&mut self, foreign_mod: ast::ForeignMod) -> ast::ForeignMod {
noop_fold_foreign_mod(self.cfg.configure_foreign_mod(foreign_mod), self)
}
fn fold_foreign_item(&mut self,
foreign_item: ast::ForeignItem) -> SmallVector<ast::ForeignItem> {
let (attr, traits, foreign_item) = self.classify_item(foreign_item);
let explain = if self.cx.ecfg.proc_macro_enabled() {
feature_gate::EXPLAIN_PROC_MACROS_IN_EXTERN
} else {
feature_gate::EXPLAIN_MACROS_IN_EXTERN
};
if attr.is_some() || !traits.is_empty() {
if !self.cx.ecfg.macros_in_extern_enabled() {
if let Some(ref attr) = attr {
emit_feature_err(&self.cx.parse_sess, "macros_in_extern", attr.span,
GateIssue::Language, explain);
}
}
let item = Annotatable::ForeignItem(P(foreign_item));
return self.collect_attr(attr, traits, item, AstFragmentKind::ForeignItems)
.make_foreign_items();
}
if let ast::ForeignItemKind::Macro(mac) = foreign_item.node {
self.check_attributes(&foreign_item.attrs);
if !self.cx.ecfg.macros_in_extern_enabled() {
emit_feature_err(&self.cx.parse_sess, "macros_in_extern", foreign_item.span,
GateIssue::Language, explain);
}
return self.collect_bang(mac, foreign_item.span, AstFragmentKind::ForeignItems)
.make_foreign_items();
}
noop_fold_foreign_item(foreign_item, self)
}
fn fold_item_kind(&mut self, item: ast::ItemKind) -> ast::ItemKind {
match item {
ast::ItemKind::MacroDef(..) => item,
_ => noop_fold_item_kind(self.cfg.configure_item_kind(item), self),
}
}
fn fold_generic_param(&mut self, param: ast::GenericParam) -> ast::GenericParam {
self.cfg.disallow_cfg_on_generic_param(¶m);
noop_fold_generic_param(param, self)
}
fn fold_attribute(&mut self, at: ast::Attribute) -> Option<ast::Attribute> {
if !at.check_name("doc") {
return noop_fold_attribute(at, self);
}
if let Some(list) = at.meta_item_list() {
if !list.iter().any(|it| it.check_name("include")) {
return noop_fold_attribute(at, self);
}
let mut items = vec![];
for it in list {
if !it.check_name("include") {
items.push(noop_fold_meta_list_item(it, self));
continue;
}
if let Some(file) = it.value_str() {
let err_count = self.cx.parse_sess.span_diagnostic.err_count();
self.check_attribute(&at);
if self.cx.parse_sess.span_diagnostic.err_count() > err_count {
return noop_fold_attribute(at, self);
}
let mut buf = vec![];
let filename = self.cx.root_path.join(file.to_string());
match File::open(&filename).and_then(|mut f| f.read_to_end(&mut buf)) {
Ok(..) => {}
Err(e) => {
self.cx.span_err(at.span,
&format!("couldn't read {}: {}",
filename.display(),
e));
}
}
match String::from_utf8(buf) {
Ok(src) => {
let src_interned = Symbol::intern(&src);
self.cx.codemap().new_filemap(filename.into(), src);
let include_info = vec![
dummy_spanned(ast::NestedMetaItemKind::MetaItem(
attr::mk_name_value_item_str(Ident::from_str("file"),
dummy_spanned(file)))),
dummy_spanned(ast::NestedMetaItemKind::MetaItem(
attr::mk_name_value_item_str(Ident::from_str("contents"),
dummy_spanned(src_interned)))),
];
let include_ident = Ident::from_str("include");
let item = attr::mk_list_item(DUMMY_SP, include_ident, include_info);
items.push(dummy_spanned(ast::NestedMetaItemKind::MetaItem(item)));
}
Err(_) => {
self.cx.span_err(at.span,
&format!("{} wasn't a utf-8 file",
filename.display()));
}
}
} else {
items.push(noop_fold_meta_list_item(it, self));
}
}
let meta = attr::mk_list_item(DUMMY_SP, Ident::from_str("doc"), items);
match at.style {
ast::AttrStyle::Inner =>
Some(attr::mk_spanned_attr_inner(at.span, at.id, meta)),
ast::AttrStyle::Outer =>
Some(attr::mk_spanned_attr_outer(at.span, at.id, meta)),
}
} else {
noop_fold_attribute(at, self)
}
}
fn new_id(&mut self, id: ast::NodeId) -> ast::NodeId {
if self.monotonic {
assert_eq!(id, ast::DUMMY_NODE_ID);
self.cx.resolver.next_node_id()
} else {
id
}
}
}
pub struct ExpansionConfig<'feat> {
pub crate_name: String,
pub features: Option<&'feat Features>,
pub recursion_limit: usize,
pub trace_mac: bool,
pub should_test: bool, pub single_step: bool,
pub keep_macs: bool,
}
macro_rules! feature_tests {
($( fn $getter:ident = $field:ident, )*) => {
$(
pub fn $getter(&self) -> bool {
match self.features {
Some(&Features { $field: true, .. }) => true,
_ => false,
}
}
)*
}
}
impl<'feat> ExpansionConfig<'feat> {
pub fn default(crate_name: String) -> ExpansionConfig<'static> {
ExpansionConfig {
crate_name,
features: None,
recursion_limit: 1024,
trace_mac: false,
should_test: false,
single_step: false,
keep_macs: false,
}
}
feature_tests! {
fn enable_quotes = quote,
fn enable_asm = asm,
fn enable_global_asm = global_asm,
fn enable_log_syntax = log_syntax,
fn enable_concat_idents = concat_idents,
fn enable_trace_macros = trace_macros,
fn enable_allow_internal_unstable = allow_internal_unstable,
fn enable_custom_derive = custom_derive,
fn proc_macro_enabled = proc_macro,
fn macros_in_extern_enabled = macros_in_extern,
fn proc_macro_mod = proc_macro_mod,
fn proc_macro_gen = proc_macro_gen,
fn proc_macro_expr = proc_macro_expr,
fn proc_macro_non_items = proc_macro_non_items,
}
}
#[derive(Debug)]
pub struct Marker(pub Mark);
impl Folder for Marker {
fn new_span(&mut self, span: Span) -> Span {
span.apply_mark(self.0)
}
fn fold_mac(&mut self, mac: ast::Mac) -> ast::Mac {
noop_fold_mac(mac, self)
}
}