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use crate::ast::{self, Attribute, Name, PatKind};
use crate::attr::{HasAttrs, Stability, Deprecation};
use crate::source_map::{SourceMap, Spanned, respan};
use crate::edition::Edition;
use crate::ext::expand::{self, AstFragment, Invocation};
use crate::ext::hygiene::{Mark, SyntaxContext, Transparency};
use crate::mut_visit::{self, MutVisitor};
use crate::parse::{self, parser, DirectoryOwnership};
use crate::parse::token;
use crate::ptr::P;
use crate::symbol::{kw, sym, Ident, Symbol};
use crate::{ThinVec, MACRO_ARGUMENTS};
use crate::tokenstream::{self, TokenStream, TokenTree};
use errors::{DiagnosticBuilder, DiagnosticId};
use smallvec::{smallvec, SmallVec};
use syntax_pos::{Span, MultiSpan, DUMMY_SP};
use syntax_pos::hygiene::{ExpnInfo, ExpnKind};
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::sync::{self, Lrc};
use std::iter;
use std::path::PathBuf;
use std::rc::Rc;
use std::default::Default;
pub use syntax_pos::hygiene::MacroKind;
#[derive(Debug,Clone)]
pub enum Annotatable {
Item(P<ast::Item>),
TraitItem(P<ast::TraitItem>),
ImplItem(P<ast::ImplItem>),
ForeignItem(P<ast::ForeignItem>),
Stmt(P<ast::Stmt>),
Expr(P<ast::Expr>),
}
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,
Annotatable::ForeignItem(ref foreign_item) => &foreign_item.attrs,
Annotatable::Stmt(ref stmt) => stmt.attrs(),
Annotatable::Expr(ref expr) => &expr.attrs,
}
}
fn visit_attrs<F: FnOnce(&mut Vec<Attribute>)>(&mut self, f: F) {
match self {
Annotatable::Item(item) => item.visit_attrs(f),
Annotatable::TraitItem(trait_item) => trait_item.visit_attrs(f),
Annotatable::ImplItem(impl_item) => impl_item.visit_attrs(f),
Annotatable::ForeignItem(foreign_item) => foreign_item.visit_attrs(f),
Annotatable::Stmt(stmt) => stmt.visit_attrs(f),
Annotatable::Expr(expr) => expr.visit_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,
Annotatable::ForeignItem(ref foreign_item) => foreign_item.span,
Annotatable::Stmt(ref stmt) => stmt.span,
Annotatable::Expr(ref expr) => expr.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 expect_foreign_item(self) -> ast::ForeignItem {
match self {
Annotatable::ForeignItem(i) => i.into_inner(),
_ => panic!("expected foreign item")
}
}
pub fn expect_stmt(self) -> ast::Stmt {
match self {
Annotatable::Stmt(stmt) => stmt.into_inner(),
_ => panic!("expected statement"),
}
}
pub fn expect_expr(self) -> P<ast::Expr> {
match self {
Annotatable::Expr(expr) => expr,
_ => panic!("expected expression"),
}
}
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,
}
}
}
// `meta_item` is the annotation, and `item` is the item being modified.
// FIXME Decorators should follow the same pattern too.
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 {
// FIXME setup implicit context in TLS before calling self.
(*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 {
// FIXME setup implicit context in TLS before calling self.
(*self)(annotation, annotated)
}
}
/// Represents a thing that maps token trees to Macro Results
pub trait TTMacroExpander {
fn expand<'cx>(
&self,
ecx: &'cx mut ExtCtxt<'_>,
span: Span,
input: TokenStream,
) -> Box<dyn MacResult+'cx>;
}
pub type MacroExpanderFn =
for<'cx> fn(&'cx mut ExtCtxt<'_>, Span, &[tokenstream::TokenTree])
-> Box<dyn MacResult+'cx>;
impl<F> TTMacroExpander for F
where F: for<'cx> Fn(&'cx mut ExtCtxt<'_>, Span, &[tokenstream::TokenTree])
-> Box<dyn MacResult+'cx>
{
fn expand<'cx>(
&self,
ecx: &'cx mut ExtCtxt<'_>,
span: Span,
input: TokenStream,
) -> Box<dyn MacResult+'cx> {
struct AvoidInterpolatedIdents;
impl MutVisitor for AvoidInterpolatedIdents {
fn visit_tt(&mut self, tt: &mut tokenstream::TokenTree) {
if let tokenstream::TokenTree::Token(token) = tt {
if let token::Interpolated(nt) = &token.kind {
if let token::NtIdent(ident, is_raw) = **nt {
*tt = tokenstream::TokenTree::token(
token::Ident(ident.name, is_raw), ident.span
);
}
}
}
mut_visit::noop_visit_tt(tt, self)
}
fn visit_mac(&mut self, mac: &mut ast::Mac) {
mut_visit::noop_visit_mac(mac, self)
}
}
let input: Vec<_> =
input.trees().map(|mut tt| { AvoidInterpolatedIdents.visit_tt(&mut tt); tt }).collect();
(*self)(ecx, span, &input)
}
}
// Use a macro because forwarding to a simple function has type system issues
macro_rules! make_stmts_default {
($me:expr) => {
$me.make_expr().map(|e| smallvec![ast::Stmt {
id: ast::DUMMY_NODE_ID,
span: e.span,
node: ast::StmtKind::Expr(e),
}])
}
}
/// The result of a macro expansion. The return values of the various
/// methods are spliced into the AST at the callsite of the macro.
pub trait MacResult {
/// Creates an expression.
fn make_expr(self: Box<Self>) -> Option<P<ast::Expr>> {
None
}
/// Creates zero or more items.
fn make_items(self: Box<Self>) -> Option<SmallVec<[P<ast::Item>; 1]>> {
None
}
/// Creates zero or more impl items.
fn make_impl_items(self: Box<Self>) -> Option<SmallVec<[ast::ImplItem; 1]>> {
None
}
/// Creates zero or more trait items.
fn make_trait_items(self: Box<Self>) -> Option<SmallVec<[ast::TraitItem; 1]>> {
None
}
/// Creates zero or more items in an `extern {}` block
fn make_foreign_items(self: Box<Self>) -> Option<SmallVec<[ast::ForeignItem; 1]>> { None }
/// Creates a pattern.
fn make_pat(self: Box<Self>) -> Option<P<ast::Pat>> {
None
}
/// Creates zero or more statements.
///
/// By default this attempts to create an expression statement,
/// returning None if that fails.
fn make_stmts(self: Box<Self>) -> Option<SmallVec<[ast::Stmt; 1]>> {
make_stmts_default!(self)
}
fn make_ty(self: Box<Self>) -> Option<P<ast::Ty>> {
None
}
}
macro_rules! make_MacEager {
( $( $fld:ident: $t:ty, )* ) => {
/// `MacResult` implementation for the common case where you've already
/// built each form of AST that you might return.
#[derive(Default)]
pub struct MacEager {
$(
pub $fld: Option<$t>,
)*
}
impl MacEager {
$(
pub fn $fld(v: $t) -> Box<dyn MacResult> {
Box::new(MacEager {
$fld: Some(v),
..Default::default()
})
}
)*
}
}
}
make_MacEager! {
expr: P<ast::Expr>,
pat: P<ast::Pat>,
items: SmallVec<[P<ast::Item>; 1]>,
impl_items: SmallVec<[ast::ImplItem; 1]>,
trait_items: SmallVec<[ast::TraitItem; 1]>,
foreign_items: SmallVec<[ast::ForeignItem; 1]>,
stmts: SmallVec<[ast::Stmt; 1]>,
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<SmallVec<[P<ast::Item>; 1]>> {
self.items
}
fn make_impl_items(self: Box<Self>) -> Option<SmallVec<[ast::ImplItem; 1]>> {
self.impl_items
}
fn make_trait_items(self: Box<Self>) -> Option<SmallVec<[ast::TraitItem; 1]>> {
self.trait_items
}
fn make_foreign_items(self: Box<Self>) -> Option<SmallVec<[ast::ForeignItem; 1]>> {
self.foreign_items
}
fn make_stmts(self: Box<Self>) -> Option<SmallVec<[ast::Stmt; 1]>> {
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
}
}
/// Fill-in macro expansion result, to allow compilation to continue
/// after hitting errors.
#[derive(Copy, Clone)]
pub struct DummyResult {
expr_only: bool,
is_error: bool,
span: Span,
}
impl DummyResult {
/// Creates a default MacResult that can be anything.
///
/// Use this as a return value after hitting any errors and
/// calling `span_err`.
pub fn any(span: Span) -> Box<dyn MacResult+'static> {
Box::new(DummyResult { expr_only: false, is_error: true, span })
}
/// Same as `any`, but must be a valid fragment, not error.
pub fn any_valid(span: Span) -> Box<dyn MacResult+'static> {
Box::new(DummyResult { expr_only: false, is_error: false, span })
}
/// Creates a default MacResult that can only be an expression.
///
/// Use this for macros that must expand to an expression, so even
/// if an error is encountered internally, the user will receive
/// an error that they also used it in the wrong place.
pub fn expr(span: Span) -> Box<dyn MacResult+'static> {
Box::new(DummyResult { expr_only: true, is_error: true, span })
}
/// A plain dummy expression.
pub fn raw_expr(sp: Span, is_error: bool) -> P<ast::Expr> {
P(ast::Expr {
id: ast::DUMMY_NODE_ID,
node: if is_error { ast::ExprKind::Err } else { ast::ExprKind::Tup(Vec::new()) },
span: sp,
attrs: ThinVec::new(),
})
}
/// A plain dummy pattern.
pub fn raw_pat(sp: Span) -> ast::Pat {
ast::Pat {
id: ast::DUMMY_NODE_ID,
node: PatKind::Wild,
span: sp,
}
}
/// A plain dummy type.
pub fn raw_ty(sp: Span, is_error: bool) -> P<ast::Ty> {
P(ast::Ty {
id: ast::DUMMY_NODE_ID,
node: if is_error { ast::TyKind::Err } else { ast::TyKind::Tup(Vec::new()) },
span: sp
})
}
}
impl MacResult for DummyResult {
fn make_expr(self: Box<DummyResult>) -> Option<P<ast::Expr>> {
Some(DummyResult::raw_expr(self.span, self.is_error))
}
fn make_pat(self: Box<DummyResult>) -> Option<P<ast::Pat>> {
Some(P(DummyResult::raw_pat(self.span)))
}
fn make_items(self: Box<DummyResult>) -> Option<SmallVec<[P<ast::Item>; 1]>> {
// this code needs a comment... why not always just return the Some() ?
if self.expr_only {
None
} else {
Some(SmallVec::new())
}
}
fn make_impl_items(self: Box<DummyResult>) -> Option<SmallVec<[ast::ImplItem; 1]>> {
if self.expr_only {
None
} else {
Some(SmallVec::new())
}
}
fn make_trait_items(self: Box<DummyResult>) -> Option<SmallVec<[ast::TraitItem; 1]>> {
if self.expr_only {
None
} else {
Some(SmallVec::new())
}
}
fn make_foreign_items(self: Box<Self>) -> Option<SmallVec<[ast::ForeignItem; 1]>> {
if self.expr_only {
None
} else {
Some(SmallVec::new())
}
}
fn make_stmts(self: Box<DummyResult>) -> Option<SmallVec<[ast::Stmt; 1]>> {
Some(smallvec![ast::Stmt {
id: ast::DUMMY_NODE_ID,
node: ast::StmtKind::Expr(DummyResult::raw_expr(self.span, self.is_error)),
span: self.span,
}])
}
fn make_ty(self: Box<DummyResult>) -> Option<P<ast::Ty>> {
Some(DummyResult::raw_ty(self.span, self.is_error))
}
}
/// A syntax extension kind.
pub enum SyntaxExtensionKind {
/// A token-based function-like macro.
Bang(
/// An expander with signature TokenStream -> TokenStream.
Box<dyn ProcMacro + sync::Sync + sync::Send>,
),
/// An AST-based function-like macro.
LegacyBang(
/// An expander with signature TokenStream -> AST.
Box<dyn TTMacroExpander + sync::Sync + sync::Send>,
),
/// A token-based attribute macro.
Attr(
/// An expander with signature (TokenStream, TokenStream) -> TokenStream.
/// The first TokenSteam is the attribute itself, the second is the annotated item.
/// The produced TokenSteam replaces the input TokenSteam.
Box<dyn AttrProcMacro + sync::Sync + sync::Send>,
),
/// An AST-based attribute macro.
LegacyAttr(
/// An expander with signature (AST, AST) -> AST.
/// The first AST fragment is the attribute itself, the second is the annotated item.
/// The produced AST fragment replaces the input AST fragment.
Box<dyn MultiItemModifier + sync::Sync + sync::Send>,
),
/// A trivial attribute "macro" that does nothing,
/// only keeps the attribute and marks it as inert,
/// thus making it ineligible for further expansion.
NonMacroAttr {
/// Suppresses the `unused_attributes` lint for this attribute.
mark_used: bool,
},
/// A token-based derive macro.
Derive(
/// An expander with signature TokenStream -> TokenStream (not yet).
/// The produced TokenSteam is appended to the input TokenSteam.
Box<dyn MultiItemModifier + sync::Sync + sync::Send>,
),
/// An AST-based derive macro.
LegacyDerive(
/// An expander with signature AST -> AST.
/// The produced AST fragment is appended to the input AST fragment.
Box<dyn MultiItemModifier + sync::Sync + sync::Send>,
),
}
/// A struct representing a macro definition in "lowered" form ready for expansion.
pub struct SyntaxExtension {
/// A syntax extension kind.
pub kind: SyntaxExtensionKind,
/// Span of the macro definition.
pub span: Span,
/// Hygienic properties of spans produced by this macro by default.
pub default_transparency: Transparency,
/// Whitelist of unstable features that are treated as stable inside this macro.
pub allow_internal_unstable: Option<Lrc<[Symbol]>>,
/// Suppresses the `unsafe_code` lint for code produced by this macro.
pub allow_internal_unsafe: bool,
/// Enables the macro helper hack (`ident!(...)` -> `$crate::ident!(...)`) for this macro.
pub local_inner_macros: bool,
/// The macro's stability info.
pub stability: Option<Stability>,
/// The macro's deprecation info.
pub deprecation: Option<Deprecation>,
/// Names of helper attributes registered by this macro.
pub helper_attrs: Vec<Symbol>,
/// Edition of the crate in which this macro is defined.
pub edition: Edition,
}
impl SyntaxExtensionKind {
/// When a syntax extension is constructed,
/// its transparency can often be inferred from its kind.
fn default_transparency(&self) -> Transparency {
match self {
SyntaxExtensionKind::Bang(..) |
SyntaxExtensionKind::Attr(..) |
SyntaxExtensionKind::Derive(..) |
SyntaxExtensionKind::NonMacroAttr { .. } => Transparency::Opaque,
SyntaxExtensionKind::LegacyBang(..) |
SyntaxExtensionKind::LegacyAttr(..) |
SyntaxExtensionKind::LegacyDerive(..) => Transparency::SemiTransparent,
}
}
}
impl SyntaxExtension {
/// Returns which kind of macro calls this syntax extension.
pub fn macro_kind(&self) -> MacroKind {
match self.kind {
SyntaxExtensionKind::Bang(..) |
SyntaxExtensionKind::LegacyBang(..) => MacroKind::Bang,
SyntaxExtensionKind::Attr(..) |
SyntaxExtensionKind::LegacyAttr(..) |
SyntaxExtensionKind::NonMacroAttr { .. } => MacroKind::Attr,
SyntaxExtensionKind::Derive(..) |
SyntaxExtensionKind::LegacyDerive(..) => MacroKind::Derive,
}
}
/// Constructs a syntax extension with default properties.
pub fn default(kind: SyntaxExtensionKind, edition: Edition) -> SyntaxExtension {
SyntaxExtension {
span: DUMMY_SP,
default_transparency: kind.default_transparency(),
allow_internal_unstable: None,
allow_internal_unsafe: false,
local_inner_macros: false,
stability: None,
deprecation: None,
helper_attrs: Vec::new(),
edition,
kind,
}
}
pub fn dummy_bang(edition: Edition) -> SyntaxExtension {
fn expander<'cx>(_: &'cx mut ExtCtxt<'_>, span: Span, _: &[TokenTree])
-> Box<dyn MacResult + 'cx> {
DummyResult::any(span)
}
SyntaxExtension::default(SyntaxExtensionKind::LegacyBang(Box::new(expander)), edition)
}
pub fn dummy_derive(edition: Edition) -> SyntaxExtension {
fn expander(_: &mut ExtCtxt<'_>, _: Span, _: &ast::MetaItem, _: Annotatable)
-> Vec<Annotatable> {
Vec::new()
}
SyntaxExtension::default(SyntaxExtensionKind::Derive(Box::new(expander)), edition)
}
pub fn non_macro_attr(mark_used: bool, edition: Edition) -> SyntaxExtension {
SyntaxExtension::default(SyntaxExtensionKind::NonMacroAttr { mark_used }, edition)
}
pub fn expn_info(&self, call_site: Span, descr: Symbol) -> ExpnInfo {
ExpnInfo {
call_site,
kind: ExpnKind::Macro(self.macro_kind(), descr),
def_site: self.span,
default_transparency: self.default_transparency,
allow_internal_unstable: self.allow_internal_unstable.clone(),
allow_internal_unsafe: self.allow_internal_unsafe,
local_inner_macros: self.local_inner_macros,
edition: self.edition,
}
}
}
pub type NamedSyntaxExtension = (Name, SyntaxExtension);
/// Error type that denotes indeterminacy.
pub struct Indeterminate;
pub trait Resolver {
fn next_node_id(&mut self) -> ast::NodeId;
fn get_module_scope(&mut self, id: ast::NodeId) -> Mark;
fn resolve_dollar_crates(&mut self);
fn visit_ast_fragment_with_placeholders(&mut self, mark: Mark, fragment: &AstFragment,
derives: &[Mark]);
fn add_builtin(&mut self, ident: ast::Ident, ext: Lrc<SyntaxExtension>);
fn resolve_imports(&mut self);
fn resolve_macro_invocation(&mut self, invoc: &Invocation, invoc_id: Mark, force: bool)
-> Result<Option<Lrc<SyntaxExtension>>, Indeterminate>;
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,
}
/// One of these is made during expansion and incrementally updated as we go;
/// when a macro expansion occurs, the resulting nodes have the `backtrace()
/// -> expn_info` of their expansion context stored into their span.
pub struct ExtCtxt<'a> {
pub parse_sess: &'a parse::ParseSess,
pub ecfg: expand::ExpansionConfig<'a>,
pub root_path: PathBuf,
pub resolver: &'a mut dyn Resolver,
pub current_expansion: ExpansionData,
pub expansions: FxHashMap<Span, Vec<String>>,
pub allow_derive_markers: Lrc<[Symbol]>,
}
impl<'a> ExtCtxt<'a> {
pub fn new(parse_sess: &'a parse::ParseSess,
ecfg: expand::ExpansionConfig<'a>,
resolver: &'a mut dyn Resolver)
-> ExtCtxt<'a> {
ExtCtxt {
parse_sess,
ecfg,
root_path: PathBuf::new(),
resolver,
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 },
},
expansions: FxHashMap::default(),
allow_derive_markers: [sym::rustc_attrs, sym::structural_match][..].into(),
}
}
/// Returns a `Folder` for deeply expanding all macros in an AST node.
pub fn expander<'b>(&'b mut self) -> expand::MacroExpander<'b, 'a> {
expand::MacroExpander::new(self, false)
}
/// Returns a `Folder` that deeply expands all macros and assigns all `NodeId`s in an AST node.
/// Once `NodeId`s are assigned, the node may not be expanded, removed, or otherwise modified.
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(), MACRO_ARGUMENTS)
}
pub fn source_map(&self) -> &'a SourceMap { self.parse_sess.source_map() }
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)
}
/// Returns span for the macro which originally caused the current expansion to happen.
///
/// Stops backtracing at include! boundary.
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.kind.descr() == sym::include {
// Stop going up the backtrace once include! is encountered
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)
}
/// Emit `msg` attached to `sp`, and stop compilation immediately.
///
/// `span_err` should be strongly preferred where-ever possible:
/// this should *only* be used when:
///
/// - continuing has a high risk of flow-on errors (e.g., errors in
/// declaring a macro would cause all uses of that macro to
/// complain about "undefined macro"), or
/// - there is literally nothing else that can be done (however,
/// in most cases one can construct a dummy expression/item to
/// substitute; we never hit resolve/type-checking so the dummy
/// value doesn't have to match anything)
pub fn span_fatal<S: Into<MultiSpan>>(&self, sp: S, msg: &str) -> ! {
self.parse_sess.span_diagnostic.span_fatal(sp, msg).raise();
}
/// Emit `msg` attached to `sp`, without immediately stopping
/// compilation.
///
/// Compilation will be stopped in the near future (at the end of
/// the macro expansion phase).
pub fn span_err<S: Into<MultiSpan>>(&self, sp: S, msg: &str) {
self.parse_sess.span_diagnostic.span_err(sp, msg);
}
pub fn span_err_with_code<S: Into<MultiSpan>>(&self, sp: S, msg: &str, code: DiagnosticId) {
self.parse_sess.span_diagnostic.span_err_with_code(sp, msg, code);
}
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();
}
// Fixme: does this result in errors?
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: &[Symbol]) -> Vec<ast::Ident> {
let def_site = DUMMY_SP.apply_mark(self.current_expansion.mark);
iter::once(Ident::new(kw::DollarCrate, def_site))
.chain(components.iter().map(|&s| Ident::with_empty_ctxt(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();
}
}
/// Extracts a string literal from the macro expanded version of `expr`,
/// emitting `err_msg` if `expr` is not a string literal. This does not stop
/// compilation on error, merely emits a non-fatal error and returns `None`.
pub fn expr_to_spanned_string<'a>(
cx: &'a mut ExtCtxt<'_>,
mut expr: P<ast::Expr>,
err_msg: &str,
) -> Result<Spanned<(Symbol, ast::StrStyle)>, Option<DiagnosticBuilder<'a>>> {
// Update `expr.span`'s ctxt now in case expr is an `include!` macro invocation.
expr.span = expr.span.apply_mark(cx.current_expansion.mark);
// we want to be able to handle e.g., `concat!("foo", "bar")`
cx.expander().visit_expr(&mut expr);
Err(match expr.node {
ast::ExprKind::Lit(ref l) => match l.node {
ast::LitKind::Str(s, style) => return Ok(respan(expr.span, (s, style))),
ast::LitKind::Err(_) => None,
_ => Some(cx.struct_span_err(l.span, err_msg))
},
ast::ExprKind::Err => None,
_ => Some(cx.struct_span_err(expr.span, err_msg))
})
}
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_err(|err| err.map(|mut err| err.emit()))
.ok()
.map(|s| s.node)
}
/// Non-fatally assert that `tts` is empty. Note that this function
/// returns even when `tts` is non-empty, macros that *need* to stop
/// compilation should call
/// `cx.parse_sess.span_diagnostic.abort_if_errors()` (this should be
/// done as rarely as possible).
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));
}
}
/// Interpreting `tts` as a comma-separated sequence of expressions,
/// expect exactly one string literal, or emit an error and return `None`.
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()
})
}
/// Extracts comma-separated expressions from `tts`. If there is a
/// parsing error, emit a non-fatal error and return `None`.
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 {
let mut expr = panictry!(p.parse_expr());
cx.expander().visit_expr(&mut expr);
es.push(expr);
if p.eat(&token::Comma) {
continue;
}
if p.token != token::Eof {
cx.span_err(sp, "expected token: `,`");
return None;
}
}
Some(es)
}
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