1132 lines
50 KiB
Rust
1132 lines
50 KiB
Rust
//! A bunch of methods and structures more or less related to resolving macros and
|
|
//! interface provided by `Resolver` to macro expander.
|
|
|
|
use crate::imports::ImportResolver;
|
|
use crate::Namespace::*;
|
|
use crate::{AmbiguityError, AmbiguityErrorMisc, AmbiguityKind, BuiltinMacroState, Determinacy};
|
|
use crate::{CrateLint, ParentScope, ResolutionError, Resolver, Scope, ScopeSet, Weak};
|
|
use crate::{ModuleKind, ModuleOrUniformRoot, NameBinding, PathResult, Segment, ToNameBinding};
|
|
use rustc_ast::{self as ast, NodeId};
|
|
use rustc_ast_lowering::ResolverAstLowering;
|
|
use rustc_ast_pretty::pprust;
|
|
use rustc_attr::StabilityLevel;
|
|
use rustc_data_structures::fx::FxHashSet;
|
|
use rustc_data_structures::ptr_key::PtrKey;
|
|
use rustc_errors::struct_span_err;
|
|
use rustc_expand::base::{Indeterminate, InvocationRes, ResolverExpand, SyntaxExtension};
|
|
use rustc_expand::compile_declarative_macro;
|
|
use rustc_expand::expand::{AstFragment, AstFragmentKind, Invocation, InvocationKind};
|
|
use rustc_feature::is_builtin_attr_name;
|
|
use rustc_hir::def::{self, DefKind, NonMacroAttrKind};
|
|
use rustc_hir::def_id;
|
|
use rustc_middle::middle::stability;
|
|
use rustc_middle::ty;
|
|
use rustc_session::lint::builtin::UNUSED_MACROS;
|
|
use rustc_session::Session;
|
|
use rustc_span::edition::Edition;
|
|
use rustc_span::hygiene::{self, ExpnData, ExpnId, ExpnKind};
|
|
use rustc_span::symbol::{kw, sym, Ident, Symbol};
|
|
use rustc_span::{Span, DUMMY_SP};
|
|
|
|
use rustc_data_structures::sync::Lrc;
|
|
use rustc_span::hygiene::{AstPass, MacroKind};
|
|
use std::cell::Cell;
|
|
use std::{mem, ptr};
|
|
|
|
type Res = def::Res<NodeId>;
|
|
|
|
/// Binding produced by a `macro_rules` item.
|
|
/// Not modularized, can shadow previous `macro_rules` bindings, etc.
|
|
#[derive(Debug)]
|
|
pub struct MacroRulesBinding<'a> {
|
|
crate binding: &'a NameBinding<'a>,
|
|
/// `macro_rules` scope into which the `macro_rules` item was planted.
|
|
crate parent_macro_rules_scope: MacroRulesScopeRef<'a>,
|
|
crate ident: Ident,
|
|
}
|
|
|
|
/// The scope introduced by a `macro_rules!` macro.
|
|
/// This starts at the macro's definition and ends at the end of the macro's parent
|
|
/// module (named or unnamed), or even further if it escapes with `#[macro_use]`.
|
|
/// Some macro invocations need to introduce `macro_rules` scopes too because they
|
|
/// can potentially expand into macro definitions.
|
|
#[derive(Copy, Clone, Debug)]
|
|
pub enum MacroRulesScope<'a> {
|
|
/// Empty "root" scope at the crate start containing no names.
|
|
Empty,
|
|
/// The scope introduced by a `macro_rules!` macro definition.
|
|
Binding(&'a MacroRulesBinding<'a>),
|
|
/// The scope introduced by a macro invocation that can potentially
|
|
/// create a `macro_rules!` macro definition.
|
|
Invocation(ExpnId),
|
|
}
|
|
|
|
/// `macro_rules!` scopes are always kept by reference and inside a cell.
|
|
/// The reason is that we update all scopes with value `MacroRulesScope::Invocation(invoc_id)`
|
|
/// in-place immediately after `invoc_id` gets expanded.
|
|
/// This helps to avoid uncontrollable growth of `macro_rules!` scope chains,
|
|
/// which usually grow lineraly with the number of macro invocations
|
|
/// in a module (including derives) and hurt performance.
|
|
pub(crate) type MacroRulesScopeRef<'a> = PtrKey<'a, Cell<MacroRulesScope<'a>>>;
|
|
|
|
// Macro namespace is separated into two sub-namespaces, one for bang macros and
|
|
// one for attribute-like macros (attributes, derives).
|
|
// We ignore resolutions from one sub-namespace when searching names in scope for another.
|
|
fn sub_namespace_match(candidate: Option<MacroKind>, requirement: Option<MacroKind>) -> bool {
|
|
#[derive(PartialEq)]
|
|
enum SubNS {
|
|
Bang,
|
|
AttrLike,
|
|
}
|
|
let sub_ns = |kind| match kind {
|
|
MacroKind::Bang => SubNS::Bang,
|
|
MacroKind::Attr | MacroKind::Derive => SubNS::AttrLike,
|
|
};
|
|
let candidate = candidate.map(sub_ns);
|
|
let requirement = requirement.map(sub_ns);
|
|
// "No specific sub-namespace" means "matches anything" for both requirements and candidates.
|
|
candidate.is_none() || requirement.is_none() || candidate == requirement
|
|
}
|
|
|
|
// We don't want to format a path using pretty-printing,
|
|
// `format!("{}", path)`, because that tries to insert
|
|
// line-breaks and is slow.
|
|
fn fast_print_path(path: &ast::Path) -> Symbol {
|
|
if path.segments.len() == 1 {
|
|
path.segments[0].ident.name
|
|
} else {
|
|
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 != kw::PathRoot {
|
|
path_str.push_str(&segment.ident.as_str())
|
|
}
|
|
}
|
|
Symbol::intern(&path_str)
|
|
}
|
|
}
|
|
|
|
/// The code common between processing `#![register_tool]` and `#![register_attr]`.
|
|
fn registered_idents(
|
|
sess: &Session,
|
|
attrs: &[ast::Attribute],
|
|
attr_name: Symbol,
|
|
descr: &str,
|
|
) -> FxHashSet<Ident> {
|
|
let mut registered = FxHashSet::default();
|
|
for attr in sess.filter_by_name(attrs, attr_name) {
|
|
for nested_meta in attr.meta_item_list().unwrap_or_default() {
|
|
match nested_meta.ident() {
|
|
Some(ident) => {
|
|
if let Some(old_ident) = registered.replace(ident) {
|
|
let msg = format!("{} `{}` was already registered", descr, ident);
|
|
sess.struct_span_err(ident.span, &msg)
|
|
.span_label(old_ident.span, "already registered here")
|
|
.emit();
|
|
}
|
|
}
|
|
None => {
|
|
let msg = format!("`{}` only accepts identifiers", attr_name);
|
|
let span = nested_meta.span();
|
|
sess.struct_span_err(span, &msg).span_label(span, "not an identifier").emit();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
registered
|
|
}
|
|
|
|
crate fn registered_attrs_and_tools(
|
|
sess: &Session,
|
|
attrs: &[ast::Attribute],
|
|
) -> (FxHashSet<Ident>, FxHashSet<Ident>) {
|
|
let registered_attrs = registered_idents(sess, attrs, sym::register_attr, "attribute");
|
|
let mut registered_tools = registered_idents(sess, attrs, sym::register_tool, "tool");
|
|
// We implicitly add `rustfmt` and `clippy` to known tools,
|
|
// but it's not an error to register them explicitly.
|
|
let predefined_tools = [sym::clippy, sym::rustfmt];
|
|
registered_tools.extend(predefined_tools.iter().cloned().map(Ident::with_dummy_span));
|
|
(registered_attrs, registered_tools)
|
|
}
|
|
|
|
impl<'a> ResolverExpand for Resolver<'a> {
|
|
fn next_node_id(&mut self) -> NodeId {
|
|
self.next_node_id()
|
|
}
|
|
|
|
fn resolve_dollar_crates(&mut self) {
|
|
hygiene::update_dollar_crate_names(|ctxt| {
|
|
let ident = Ident::new(kw::DollarCrate, DUMMY_SP.with_ctxt(ctxt));
|
|
match self.resolve_crate_root(ident).kind {
|
|
ModuleKind::Def(.., name) if name != kw::Invalid => name,
|
|
_ => kw::Crate,
|
|
}
|
|
});
|
|
}
|
|
|
|
fn visit_ast_fragment_with_placeholders(&mut self, expansion: ExpnId, fragment: &AstFragment) {
|
|
// Integrate the new AST fragment into all the definition and module structures.
|
|
// We are inside the `expansion` now, but other parent scope components are still the same.
|
|
let parent_scope = ParentScope { expansion, ..self.invocation_parent_scopes[&expansion] };
|
|
let output_macro_rules_scope = self.build_reduced_graph(fragment, parent_scope);
|
|
self.output_macro_rules_scopes.insert(expansion, output_macro_rules_scope);
|
|
|
|
// Update all `macro_rules` scopes referring to this invocation. This is an optimization
|
|
// used to avoid long scope chains, see the comments on `MacroRulesScopeRef`.
|
|
if let Some(invocation_scopes) = self.invocation_macro_rules_scopes.remove(&expansion) {
|
|
for invocation_scope in &invocation_scopes {
|
|
invocation_scope.set(output_macro_rules_scope.get());
|
|
}
|
|
// All `macro_rules` scopes that previously referred to `expansion`
|
|
// are now rerouted to its output scope, if it's also an invocation.
|
|
if let MacroRulesScope::Invocation(invoc_id) = output_macro_rules_scope.get() {
|
|
self.invocation_macro_rules_scopes
|
|
.entry(invoc_id)
|
|
.or_default()
|
|
.extend(invocation_scopes);
|
|
}
|
|
}
|
|
|
|
parent_scope.module.unexpanded_invocations.borrow_mut().remove(&expansion);
|
|
}
|
|
|
|
fn register_builtin_macro(&mut self, ident: Ident, ext: SyntaxExtension) {
|
|
if self.builtin_macros.insert(ident.name, BuiltinMacroState::NotYetSeen(ext)).is_some() {
|
|
self.session
|
|
.span_err(ident.span, &format!("built-in macro `{}` was already defined", ident));
|
|
}
|
|
}
|
|
|
|
// Create a new Expansion with a definition site of the provided module, or
|
|
// a fake empty `#[no_implicit_prelude]` module if no module is provided.
|
|
fn expansion_for_ast_pass(
|
|
&mut self,
|
|
call_site: Span,
|
|
pass: AstPass,
|
|
features: &[Symbol],
|
|
parent_module_id: Option<NodeId>,
|
|
) -> ExpnId {
|
|
let expn_id = ExpnId::fresh(Some(ExpnData::allow_unstable(
|
|
ExpnKind::AstPass(pass),
|
|
call_site,
|
|
self.session.edition(),
|
|
features.into(),
|
|
None,
|
|
)));
|
|
|
|
let parent_scope = if let Some(module_id) = parent_module_id {
|
|
let parent_def_id = self.local_def_id(module_id);
|
|
self.definitions.add_parent_module_of_macro_def(expn_id, parent_def_id.to_def_id());
|
|
self.module_map[&parent_def_id]
|
|
} else {
|
|
self.definitions.add_parent_module_of_macro_def(
|
|
expn_id,
|
|
def_id::DefId::local(def_id::CRATE_DEF_INDEX),
|
|
);
|
|
self.empty_module
|
|
};
|
|
self.ast_transform_scopes.insert(expn_id, parent_scope);
|
|
expn_id
|
|
}
|
|
|
|
fn resolve_imports(&mut self) {
|
|
ImportResolver { r: self }.resolve_imports()
|
|
}
|
|
|
|
fn resolve_macro_invocation(
|
|
&mut self,
|
|
invoc: &Invocation,
|
|
eager_expansion_root: ExpnId,
|
|
force: bool,
|
|
) -> Result<InvocationRes, Indeterminate> {
|
|
let invoc_id = invoc.expansion_data.id;
|
|
let parent_scope = match self.invocation_parent_scopes.get(&invoc_id) {
|
|
Some(parent_scope) => *parent_scope,
|
|
None => {
|
|
// If there's no entry in the table, then we are resolving an eagerly expanded
|
|
// macro, which should inherit its parent scope from its eager expansion root -
|
|
// the macro that requested this eager expansion.
|
|
let parent_scope = *self
|
|
.invocation_parent_scopes
|
|
.get(&eager_expansion_root)
|
|
.expect("non-eager expansion without a parent scope");
|
|
self.invocation_parent_scopes.insert(invoc_id, parent_scope);
|
|
parent_scope
|
|
}
|
|
};
|
|
|
|
let (path, kind, derives, after_derive) = match invoc.kind {
|
|
InvocationKind::Attr { ref attr, ref derives, after_derive, .. } => (
|
|
&attr.get_normal_item().path,
|
|
MacroKind::Attr,
|
|
self.arenas.alloc_ast_paths(derives),
|
|
after_derive,
|
|
),
|
|
InvocationKind::Bang { ref mac, .. } => (&mac.path, MacroKind::Bang, &[][..], false),
|
|
InvocationKind::Derive { ref path, .. } => (path, MacroKind::Derive, &[][..], false),
|
|
InvocationKind::DeriveContainer { ref derives, .. } => {
|
|
// Block expansion of the container until we resolve all derives in it.
|
|
// This is required for two reasons:
|
|
// - Derive helper attributes are in scope for the item to which the `#[derive]`
|
|
// is applied, so they have to be produced by the container's expansion rather
|
|
// than by individual derives.
|
|
// - Derives in the container need to know whether one of them is a built-in `Copy`.
|
|
// FIXME: Try to avoid repeated resolutions for derives here and in expansion.
|
|
let mut exts = Vec::new();
|
|
let mut helper_attrs = Vec::new();
|
|
for path in derives {
|
|
exts.push(
|
|
match self.resolve_macro_path(
|
|
path,
|
|
Some(MacroKind::Derive),
|
|
&parent_scope,
|
|
true,
|
|
force,
|
|
) {
|
|
Ok((Some(ext), _)) => {
|
|
let span = path
|
|
.segments
|
|
.last()
|
|
.unwrap()
|
|
.ident
|
|
.span
|
|
.normalize_to_macros_2_0();
|
|
helper_attrs.extend(
|
|
ext.helper_attrs.iter().map(|name| Ident::new(*name, span)),
|
|
);
|
|
if ext.is_derive_copy {
|
|
self.add_derive_copy(invoc_id);
|
|
}
|
|
ext
|
|
}
|
|
Ok(_) | Err(Determinacy::Determined) => {
|
|
self.dummy_ext(MacroKind::Derive)
|
|
}
|
|
Err(Determinacy::Undetermined) => return Err(Indeterminate),
|
|
},
|
|
)
|
|
}
|
|
self.helper_attrs.insert(invoc_id, helper_attrs);
|
|
return Ok(InvocationRes::DeriveContainer(exts));
|
|
}
|
|
};
|
|
|
|
// Derives are not included when `invocations` are collected, so we have to add them here.
|
|
let parent_scope = &ParentScope { derives, ..parent_scope };
|
|
let node_id = self.lint_node_id(eager_expansion_root);
|
|
let (ext, res) = self.smart_resolve_macro_path(path, kind, parent_scope, node_id, force)?;
|
|
|
|
let span = invoc.span();
|
|
invoc_id.set_expn_data(ext.expn_data(
|
|
parent_scope.expansion,
|
|
span,
|
|
fast_print_path(path),
|
|
res.opt_def_id(),
|
|
));
|
|
|
|
if let Res::Def(_, _) = res {
|
|
if after_derive {
|
|
self.session.span_err(span, "macro attributes must be placed before `#[derive]`");
|
|
}
|
|
let normal_module_def_id = self.macro_def_scope(invoc_id).normal_ancestor_id;
|
|
self.definitions.add_parent_module_of_macro_def(invoc_id, normal_module_def_id);
|
|
}
|
|
|
|
match invoc.fragment_kind {
|
|
AstFragmentKind::Arms
|
|
| AstFragmentKind::Fields
|
|
| AstFragmentKind::FieldPats
|
|
| AstFragmentKind::GenericParams
|
|
| AstFragmentKind::Params
|
|
| AstFragmentKind::StructFields
|
|
| AstFragmentKind::Variants => {
|
|
if let Res::Def(..) = res {
|
|
self.session.span_err(
|
|
span,
|
|
&format!(
|
|
"expected an inert attribute, found {} {}",
|
|
res.article(),
|
|
res.descr()
|
|
),
|
|
);
|
|
return Ok(InvocationRes::Single(self.dummy_ext(kind)));
|
|
}
|
|
}
|
|
_ => {}
|
|
}
|
|
|
|
Ok(InvocationRes::Single(ext))
|
|
}
|
|
|
|
fn check_unused_macros(&mut self) {
|
|
for (_, &(node_id, span)) in self.unused_macros.iter() {
|
|
self.lint_buffer.buffer_lint(UNUSED_MACROS, node_id, span, "unused macro definition");
|
|
}
|
|
}
|
|
|
|
fn lint_node_id(&mut self, expn_id: ExpnId) -> NodeId {
|
|
self.invocation_parents
|
|
.get(&expn_id)
|
|
.map_or(ast::CRATE_NODE_ID, |id| self.def_id_to_node_id[*id])
|
|
}
|
|
|
|
fn has_derive_copy(&self, expn_id: ExpnId) -> bool {
|
|
self.containers_deriving_copy.contains(&expn_id)
|
|
}
|
|
|
|
fn add_derive_copy(&mut self, expn_id: ExpnId) {
|
|
self.containers_deriving_copy.insert(expn_id);
|
|
}
|
|
|
|
// The function that implements the resolution logic of `#[cfg_accessible(path)]`.
|
|
// Returns true if the path can certainly be resolved in one of three namespaces,
|
|
// returns false if the path certainly cannot be resolved in any of the three namespaces.
|
|
// Returns `Indeterminate` if we cannot give a certain answer yet.
|
|
fn cfg_accessible(&mut self, expn_id: ExpnId, path: &ast::Path) -> Result<bool, Indeterminate> {
|
|
let span = path.span;
|
|
let path = &Segment::from_path(path);
|
|
let parent_scope = self.invocation_parent_scopes[&expn_id];
|
|
|
|
let mut indeterminate = false;
|
|
for ns in [TypeNS, ValueNS, MacroNS].iter().copied() {
|
|
match self.resolve_path(path, Some(ns), &parent_scope, false, span, CrateLint::No) {
|
|
PathResult::Module(ModuleOrUniformRoot::Module(_)) => return Ok(true),
|
|
PathResult::NonModule(partial_res) if partial_res.unresolved_segments() == 0 => {
|
|
return Ok(true);
|
|
}
|
|
PathResult::Indeterminate => indeterminate = true,
|
|
// FIXME: `resolve_path` is not ready to report partially resolved paths
|
|
// correctly, so we just report an error if the path was reported as unresolved.
|
|
// This needs to be fixed for `cfg_accessible` to be useful.
|
|
PathResult::NonModule(..) | PathResult::Failed { .. } => {}
|
|
PathResult::Module(_) => panic!("unexpected path resolution"),
|
|
}
|
|
}
|
|
|
|
if indeterminate {
|
|
return Err(Indeterminate);
|
|
}
|
|
|
|
self.session
|
|
.struct_span_err(span, "not sure whether the path is accessible or not")
|
|
.span_note(span, "`cfg_accessible` is not fully implemented")
|
|
.emit();
|
|
Ok(false)
|
|
}
|
|
}
|
|
|
|
impl<'a> Resolver<'a> {
|
|
/// Resolve macro path with error reporting and recovery.
|
|
fn smart_resolve_macro_path(
|
|
&mut self,
|
|
path: &ast::Path,
|
|
kind: MacroKind,
|
|
parent_scope: &ParentScope<'a>,
|
|
node_id: NodeId,
|
|
force: bool,
|
|
) -> Result<(Lrc<SyntaxExtension>, Res), Indeterminate> {
|
|
let (ext, res) = match self.resolve_macro_path(path, Some(kind), parent_scope, true, force)
|
|
{
|
|
Ok((Some(ext), res)) => (ext, res),
|
|
// Use dummy syntax extensions for unresolved macros for better recovery.
|
|
Ok((None, res)) => (self.dummy_ext(kind), res),
|
|
Err(Determinacy::Determined) => (self.dummy_ext(kind), Res::Err),
|
|
Err(Determinacy::Undetermined) => return Err(Indeterminate),
|
|
};
|
|
|
|
// Report errors for the resolved macro.
|
|
for segment in &path.segments {
|
|
if let Some(args) = &segment.args {
|
|
self.session.span_err(args.span(), "generic arguments in macro path");
|
|
}
|
|
if kind == MacroKind::Attr && segment.ident.as_str().starts_with("rustc") {
|
|
self.session.span_err(
|
|
segment.ident.span,
|
|
"attributes starting with `rustc` are reserved for use by the `rustc` compiler",
|
|
);
|
|
}
|
|
}
|
|
|
|
match res {
|
|
Res::Def(DefKind::Macro(_), def_id) => {
|
|
if let Some(def_id) = def_id.as_local() {
|
|
self.unused_macros.remove(&def_id);
|
|
if self.proc_macro_stubs.contains(&def_id) {
|
|
self.session.span_err(
|
|
path.span,
|
|
"can't use a procedural macro from the same crate that defines it",
|
|
);
|
|
}
|
|
}
|
|
}
|
|
Res::NonMacroAttr(..) | Res::Err => {}
|
|
_ => panic!("expected `DefKind::Macro` or `Res::NonMacroAttr`"),
|
|
};
|
|
|
|
self.check_stability_and_deprecation(&ext, path, node_id);
|
|
|
|
Ok(if ext.macro_kind() != kind {
|
|
let expected = kind.descr_expected();
|
|
let path_str = pprust::path_to_string(path);
|
|
let msg = format!("expected {}, found {} `{}`", expected, res.descr(), path_str);
|
|
self.session
|
|
.struct_span_err(path.span, &msg)
|
|
.span_label(path.span, format!("not {} {}", kind.article(), expected))
|
|
.emit();
|
|
// Use dummy syntax extensions for unexpected macro kinds for better recovery.
|
|
(self.dummy_ext(kind), Res::Err)
|
|
} else {
|
|
(ext, res)
|
|
})
|
|
}
|
|
|
|
pub fn resolve_macro_path(
|
|
&mut self,
|
|
path: &ast::Path,
|
|
kind: Option<MacroKind>,
|
|
parent_scope: &ParentScope<'a>,
|
|
trace: bool,
|
|
force: bool,
|
|
) -> Result<(Option<Lrc<SyntaxExtension>>, Res), Determinacy> {
|
|
let path_span = path.span;
|
|
let mut path = Segment::from_path(path);
|
|
|
|
// Possibly apply the macro helper hack
|
|
if kind == Some(MacroKind::Bang)
|
|
&& path.len() == 1
|
|
&& path[0].ident.span.ctxt().outer_expn_data().local_inner_macros
|
|
{
|
|
let root = Ident::new(kw::DollarCrate, path[0].ident.span);
|
|
path.insert(0, Segment::from_ident(root));
|
|
}
|
|
|
|
let res = if path.len() > 1 {
|
|
let res = match self.resolve_path(
|
|
&path,
|
|
Some(MacroNS),
|
|
parent_scope,
|
|
false,
|
|
path_span,
|
|
CrateLint::No,
|
|
) {
|
|
PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => {
|
|
Ok(path_res.base_res())
|
|
}
|
|
PathResult::Indeterminate if !force => return Err(Determinacy::Undetermined),
|
|
PathResult::NonModule(..)
|
|
| PathResult::Indeterminate
|
|
| PathResult::Failed { .. } => Err(Determinacy::Determined),
|
|
PathResult::Module(..) => unreachable!(),
|
|
};
|
|
|
|
if trace {
|
|
let kind = kind.expect("macro kind must be specified if tracing is enabled");
|
|
self.multi_segment_macro_resolutions.push((
|
|
path,
|
|
path_span,
|
|
kind,
|
|
*parent_scope,
|
|
res.ok(),
|
|
));
|
|
}
|
|
|
|
self.prohibit_imported_non_macro_attrs(None, res.ok(), path_span);
|
|
res
|
|
} else {
|
|
let scope_set = kind.map_or(ScopeSet::All(MacroNS, false), ScopeSet::Macro);
|
|
let binding = self.early_resolve_ident_in_lexical_scope(
|
|
path[0].ident,
|
|
scope_set,
|
|
parent_scope,
|
|
false,
|
|
force,
|
|
path_span,
|
|
);
|
|
if let Err(Determinacy::Undetermined) = binding {
|
|
return Err(Determinacy::Undetermined);
|
|
}
|
|
|
|
if trace {
|
|
let kind = kind.expect("macro kind must be specified if tracing is enabled");
|
|
self.single_segment_macro_resolutions.push((
|
|
path[0].ident,
|
|
kind,
|
|
*parent_scope,
|
|
binding.ok(),
|
|
));
|
|
}
|
|
|
|
let res = binding.map(|binding| binding.res());
|
|
self.prohibit_imported_non_macro_attrs(binding.ok(), res.ok(), path_span);
|
|
res
|
|
};
|
|
|
|
res.map(|res| (self.get_macro(res), res))
|
|
}
|
|
|
|
// Resolve an identifier in lexical scope.
|
|
// This is a variation of `fn resolve_ident_in_lexical_scope` that can be run during
|
|
// expansion and import resolution (perhaps they can be merged in the future).
|
|
// The function is used for resolving initial segments of macro paths (e.g., `foo` in
|
|
// `foo::bar!(); or `foo!();`) and also for import paths on 2018 edition.
|
|
crate fn early_resolve_ident_in_lexical_scope(
|
|
&mut self,
|
|
orig_ident: Ident,
|
|
scope_set: ScopeSet,
|
|
parent_scope: &ParentScope<'a>,
|
|
record_used: bool,
|
|
force: bool,
|
|
path_span: Span,
|
|
) -> Result<&'a NameBinding<'a>, Determinacy> {
|
|
bitflags::bitflags! {
|
|
struct Flags: u8 {
|
|
const MACRO_RULES = 1 << 0;
|
|
const MODULE = 1 << 1;
|
|
const DERIVE_HELPER_COMPAT = 1 << 2;
|
|
const MISC_SUGGEST_CRATE = 1 << 3;
|
|
const MISC_SUGGEST_SELF = 1 << 4;
|
|
const MISC_FROM_PRELUDE = 1 << 5;
|
|
}
|
|
}
|
|
|
|
assert!(force || !record_used); // `record_used` implies `force`
|
|
|
|
// Make sure `self`, `super` etc produce an error when passed to here.
|
|
if orig_ident.is_path_segment_keyword() {
|
|
return Err(Determinacy::Determined);
|
|
}
|
|
|
|
let (ns, macro_kind, is_import) = match scope_set {
|
|
ScopeSet::All(ns, is_import) => (ns, None, is_import),
|
|
ScopeSet::AbsolutePath(ns) => (ns, None, false),
|
|
ScopeSet::Macro(macro_kind) => (MacroNS, Some(macro_kind), false),
|
|
};
|
|
|
|
// This is *the* result, resolution from the scope closest to the resolved identifier.
|
|
// However, sometimes this result is "weak" because it comes from a glob import or
|
|
// a macro expansion, and in this case it cannot shadow names from outer scopes, e.g.
|
|
// mod m { ... } // solution in outer scope
|
|
// {
|
|
// use prefix::*; // imports another `m` - innermost solution
|
|
// // weak, cannot shadow the outer `m`, need to report ambiguity error
|
|
// m::mac!();
|
|
// }
|
|
// So we have to save the innermost solution and continue searching in outer scopes
|
|
// to detect potential ambiguities.
|
|
let mut innermost_result: Option<(&NameBinding<'_>, Flags)> = None;
|
|
let mut determinacy = Determinacy::Determined;
|
|
|
|
// Go through all the scopes and try to resolve the name.
|
|
let break_result = self.visit_scopes(
|
|
scope_set,
|
|
parent_scope,
|
|
orig_ident,
|
|
|this, scope, use_prelude, ident| {
|
|
let ok = |res, span, arenas| {
|
|
Ok((
|
|
(res, ty::Visibility::Public, span, ExpnId::root()).to_name_binding(arenas),
|
|
Flags::empty(),
|
|
))
|
|
};
|
|
let result = match scope {
|
|
Scope::DeriveHelpers(expn_id) => {
|
|
if let Some(attr) = this
|
|
.helper_attrs
|
|
.get(&expn_id)
|
|
.and_then(|attrs| attrs.iter().rfind(|i| ident == **i))
|
|
{
|
|
let binding = (
|
|
Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper),
|
|
ty::Visibility::Public,
|
|
attr.span,
|
|
expn_id,
|
|
)
|
|
.to_name_binding(this.arenas);
|
|
Ok((binding, Flags::empty()))
|
|
} else {
|
|
Err(Determinacy::Determined)
|
|
}
|
|
}
|
|
Scope::DeriveHelpersCompat => {
|
|
let mut result = Err(Determinacy::Determined);
|
|
for derive in parent_scope.derives {
|
|
let parent_scope = &ParentScope { derives: &[], ..*parent_scope };
|
|
match this.resolve_macro_path(
|
|
derive,
|
|
Some(MacroKind::Derive),
|
|
parent_scope,
|
|
true,
|
|
force,
|
|
) {
|
|
Ok((Some(ext), _)) => {
|
|
if ext.helper_attrs.contains(&ident.name) {
|
|
let binding = (
|
|
Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper),
|
|
ty::Visibility::Public,
|
|
derive.span,
|
|
ExpnId::root(),
|
|
)
|
|
.to_name_binding(this.arenas);
|
|
result = Ok((binding, Flags::DERIVE_HELPER_COMPAT));
|
|
break;
|
|
}
|
|
}
|
|
Ok(_) | Err(Determinacy::Determined) => {}
|
|
Err(Determinacy::Undetermined) => {
|
|
result = Err(Determinacy::Undetermined)
|
|
}
|
|
}
|
|
}
|
|
result
|
|
}
|
|
Scope::MacroRules(macro_rules_scope) => match macro_rules_scope.get() {
|
|
MacroRulesScope::Binding(macro_rules_binding)
|
|
if ident == macro_rules_binding.ident =>
|
|
{
|
|
Ok((macro_rules_binding.binding, Flags::MACRO_RULES))
|
|
}
|
|
MacroRulesScope::Invocation(invoc_id)
|
|
if !this.output_macro_rules_scopes.contains_key(&invoc_id) =>
|
|
{
|
|
Err(Determinacy::Undetermined)
|
|
}
|
|
_ => Err(Determinacy::Determined),
|
|
},
|
|
Scope::CrateRoot => {
|
|
let root_ident = Ident::new(kw::PathRoot, ident.span);
|
|
let root_module = this.resolve_crate_root(root_ident);
|
|
let binding = this.resolve_ident_in_module_ext(
|
|
ModuleOrUniformRoot::Module(root_module),
|
|
ident,
|
|
ns,
|
|
parent_scope,
|
|
record_used,
|
|
path_span,
|
|
);
|
|
match binding {
|
|
Ok(binding) => Ok((binding, Flags::MODULE | Flags::MISC_SUGGEST_CRATE)),
|
|
Err((Determinacy::Undetermined, Weak::No)) => {
|
|
return Some(Err(Determinacy::determined(force)));
|
|
}
|
|
Err((Determinacy::Undetermined, Weak::Yes)) => {
|
|
Err(Determinacy::Undetermined)
|
|
}
|
|
Err((Determinacy::Determined, _)) => Err(Determinacy::Determined),
|
|
}
|
|
}
|
|
Scope::Module(module) => {
|
|
let adjusted_parent_scope = &ParentScope { module, ..*parent_scope };
|
|
let binding = this.resolve_ident_in_module_unadjusted_ext(
|
|
ModuleOrUniformRoot::Module(module),
|
|
ident,
|
|
ns,
|
|
adjusted_parent_scope,
|
|
true,
|
|
record_used,
|
|
path_span,
|
|
);
|
|
match binding {
|
|
Ok(binding) => {
|
|
let misc_flags = if ptr::eq(module, this.graph_root) {
|
|
Flags::MISC_SUGGEST_CRATE
|
|
} else if module.is_normal() {
|
|
Flags::MISC_SUGGEST_SELF
|
|
} else {
|
|
Flags::empty()
|
|
};
|
|
Ok((binding, Flags::MODULE | misc_flags))
|
|
}
|
|
Err((Determinacy::Undetermined, Weak::No)) => {
|
|
return Some(Err(Determinacy::determined(force)));
|
|
}
|
|
Err((Determinacy::Undetermined, Weak::Yes)) => {
|
|
Err(Determinacy::Undetermined)
|
|
}
|
|
Err((Determinacy::Determined, _)) => Err(Determinacy::Determined),
|
|
}
|
|
}
|
|
Scope::RegisteredAttrs => match this.registered_attrs.get(&ident).cloned() {
|
|
Some(ident) => ok(
|
|
Res::NonMacroAttr(NonMacroAttrKind::Registered),
|
|
ident.span,
|
|
this.arenas,
|
|
),
|
|
None => Err(Determinacy::Determined),
|
|
},
|
|
Scope::MacroUsePrelude => {
|
|
match this.macro_use_prelude.get(&ident.name).cloned() {
|
|
Some(binding) => Ok((binding, Flags::MISC_FROM_PRELUDE)),
|
|
None => Err(Determinacy::determined(
|
|
this.graph_root.unexpanded_invocations.borrow().is_empty(),
|
|
)),
|
|
}
|
|
}
|
|
Scope::BuiltinAttrs => {
|
|
if is_builtin_attr_name(ident.name) {
|
|
ok(Res::NonMacroAttr(NonMacroAttrKind::Builtin), DUMMY_SP, this.arenas)
|
|
} else {
|
|
Err(Determinacy::Determined)
|
|
}
|
|
}
|
|
Scope::ExternPrelude => match this.extern_prelude_get(ident, !record_used) {
|
|
Some(binding) => Ok((binding, Flags::empty())),
|
|
None => Err(Determinacy::determined(
|
|
this.graph_root.unexpanded_invocations.borrow().is_empty(),
|
|
)),
|
|
},
|
|
Scope::ToolPrelude => match this.registered_tools.get(&ident).cloned() {
|
|
Some(ident) => ok(Res::ToolMod, ident.span, this.arenas),
|
|
None => Err(Determinacy::Determined),
|
|
},
|
|
Scope::StdLibPrelude => {
|
|
let mut result = Err(Determinacy::Determined);
|
|
if let Some(prelude) = this.prelude {
|
|
if let Ok(binding) = this.resolve_ident_in_module_unadjusted(
|
|
ModuleOrUniformRoot::Module(prelude),
|
|
ident,
|
|
ns,
|
|
parent_scope,
|
|
false,
|
|
path_span,
|
|
) {
|
|
if use_prelude || this.is_builtin_macro(binding.res()) {
|
|
result = Ok((binding, Flags::MISC_FROM_PRELUDE));
|
|
}
|
|
}
|
|
}
|
|
result
|
|
}
|
|
Scope::BuiltinTypes => {
|
|
match this.primitive_type_table.primitive_types.get(&ident.name).cloned() {
|
|
Some(prim_ty) => ok(Res::PrimTy(prim_ty), DUMMY_SP, this.arenas),
|
|
None => Err(Determinacy::Determined),
|
|
}
|
|
}
|
|
};
|
|
|
|
match result {
|
|
Ok((binding, flags))
|
|
if sub_namespace_match(binding.macro_kind(), macro_kind) =>
|
|
{
|
|
if !record_used {
|
|
return Some(Ok(binding));
|
|
}
|
|
|
|
if let Some((innermost_binding, innermost_flags)) = innermost_result {
|
|
// Found another solution, if the first one was "weak", report an error.
|
|
let (res, innermost_res) = (binding.res(), innermost_binding.res());
|
|
if res != innermost_res {
|
|
let builtin = Res::NonMacroAttr(NonMacroAttrKind::Builtin);
|
|
let is_derive_helper_compat = |res, flags: Flags| {
|
|
res == Res::NonMacroAttr(NonMacroAttrKind::DeriveHelper)
|
|
&& flags.contains(Flags::DERIVE_HELPER_COMPAT)
|
|
};
|
|
|
|
let ambiguity_error_kind = if is_import {
|
|
Some(AmbiguityKind::Import)
|
|
} else if innermost_res == builtin || res == builtin {
|
|
Some(AmbiguityKind::BuiltinAttr)
|
|
} else if is_derive_helper_compat(innermost_res, innermost_flags)
|
|
|| is_derive_helper_compat(res, flags)
|
|
{
|
|
Some(AmbiguityKind::DeriveHelper)
|
|
} else if innermost_flags.contains(Flags::MACRO_RULES)
|
|
&& flags.contains(Flags::MODULE)
|
|
&& !this.disambiguate_macro_rules_vs_modularized(
|
|
innermost_binding,
|
|
binding,
|
|
)
|
|
|| flags.contains(Flags::MACRO_RULES)
|
|
&& innermost_flags.contains(Flags::MODULE)
|
|
&& !this.disambiguate_macro_rules_vs_modularized(
|
|
binding,
|
|
innermost_binding,
|
|
)
|
|
{
|
|
Some(AmbiguityKind::MacroRulesVsModularized)
|
|
} else if innermost_binding.is_glob_import() {
|
|
Some(AmbiguityKind::GlobVsOuter)
|
|
} else if innermost_binding
|
|
.may_appear_after(parent_scope.expansion, binding)
|
|
{
|
|
Some(AmbiguityKind::MoreExpandedVsOuter)
|
|
} else {
|
|
None
|
|
};
|
|
if let Some(kind) = ambiguity_error_kind {
|
|
let misc = |f: Flags| {
|
|
if f.contains(Flags::MISC_SUGGEST_CRATE) {
|
|
AmbiguityErrorMisc::SuggestCrate
|
|
} else if f.contains(Flags::MISC_SUGGEST_SELF) {
|
|
AmbiguityErrorMisc::SuggestSelf
|
|
} else if f.contains(Flags::MISC_FROM_PRELUDE) {
|
|
AmbiguityErrorMisc::FromPrelude
|
|
} else {
|
|
AmbiguityErrorMisc::None
|
|
}
|
|
};
|
|
this.ambiguity_errors.push(AmbiguityError {
|
|
kind,
|
|
ident: orig_ident,
|
|
b1: innermost_binding,
|
|
b2: binding,
|
|
misc1: misc(innermost_flags),
|
|
misc2: misc(flags),
|
|
});
|
|
return Some(Ok(innermost_binding));
|
|
}
|
|
}
|
|
} else {
|
|
// Found the first solution.
|
|
innermost_result = Some((binding, flags));
|
|
}
|
|
}
|
|
Ok(..) | Err(Determinacy::Determined) => {}
|
|
Err(Determinacy::Undetermined) => determinacy = Determinacy::Undetermined,
|
|
}
|
|
|
|
None
|
|
},
|
|
);
|
|
|
|
if let Some(break_result) = break_result {
|
|
return break_result;
|
|
}
|
|
|
|
// The first found solution was the only one, return it.
|
|
if let Some((binding, _)) = innermost_result {
|
|
return Ok(binding);
|
|
}
|
|
|
|
Err(Determinacy::determined(determinacy == Determinacy::Determined || force))
|
|
}
|
|
|
|
crate fn finalize_macro_resolutions(&mut self) {
|
|
let check_consistency = |this: &mut Self,
|
|
path: &[Segment],
|
|
span,
|
|
kind: MacroKind,
|
|
initial_res: Option<Res>,
|
|
res: Res| {
|
|
if let Some(initial_res) = initial_res {
|
|
if res != initial_res {
|
|
// Make sure compilation does not succeed if preferred macro resolution
|
|
// has changed after the macro had been expanded. In theory all such
|
|
// situations should be reported as errors, so this is a bug.
|
|
this.session.delay_span_bug(span, "inconsistent resolution for a macro");
|
|
}
|
|
} else {
|
|
// It's possible that the macro was unresolved (indeterminate) and silently
|
|
// expanded into a dummy fragment for recovery during expansion.
|
|
// Now, post-expansion, the resolution may succeed, but we can't change the
|
|
// past and need to report an error.
|
|
// However, non-speculative `resolve_path` can successfully return private items
|
|
// even if speculative `resolve_path` returned nothing previously, so we skip this
|
|
// less informative error if the privacy error is reported elsewhere.
|
|
if this.privacy_errors.is_empty() {
|
|
let msg = format!(
|
|
"cannot determine resolution for the {} `{}`",
|
|
kind.descr(),
|
|
Segment::names_to_string(path)
|
|
);
|
|
let msg_note = "import resolution is stuck, try simplifying macro imports";
|
|
this.session.struct_span_err(span, &msg).note(msg_note).emit();
|
|
}
|
|
}
|
|
};
|
|
|
|
let macro_resolutions = mem::take(&mut self.multi_segment_macro_resolutions);
|
|
for (mut path, path_span, kind, parent_scope, initial_res) in macro_resolutions {
|
|
// FIXME: Path resolution will ICE if segment IDs present.
|
|
for seg in &mut path {
|
|
seg.id = None;
|
|
}
|
|
match self.resolve_path(
|
|
&path,
|
|
Some(MacroNS),
|
|
&parent_scope,
|
|
true,
|
|
path_span,
|
|
CrateLint::No,
|
|
) {
|
|
PathResult::NonModule(path_res) if path_res.unresolved_segments() == 0 => {
|
|
let res = path_res.base_res();
|
|
check_consistency(self, &path, path_span, kind, initial_res, res);
|
|
}
|
|
path_res @ PathResult::NonModule(..) | path_res @ PathResult::Failed { .. } => {
|
|
let (span, label) = if let PathResult::Failed { span, label, .. } = path_res {
|
|
(span, label)
|
|
} else {
|
|
(
|
|
path_span,
|
|
format!(
|
|
"partially resolved path in {} {}",
|
|
kind.article(),
|
|
kind.descr()
|
|
),
|
|
)
|
|
};
|
|
self.report_error(
|
|
span,
|
|
ResolutionError::FailedToResolve { label, suggestion: None },
|
|
);
|
|
}
|
|
PathResult::Module(..) | PathResult::Indeterminate => unreachable!(),
|
|
}
|
|
}
|
|
|
|
let macro_resolutions = mem::take(&mut self.single_segment_macro_resolutions);
|
|
for (ident, kind, parent_scope, initial_binding) in macro_resolutions {
|
|
match self.early_resolve_ident_in_lexical_scope(
|
|
ident,
|
|
ScopeSet::Macro(kind),
|
|
&parent_scope,
|
|
true,
|
|
true,
|
|
ident.span,
|
|
) {
|
|
Ok(binding) => {
|
|
let initial_res = initial_binding.map(|initial_binding| {
|
|
self.record_use(ident, MacroNS, initial_binding, false);
|
|
initial_binding.res()
|
|
});
|
|
let res = binding.res();
|
|
let seg = Segment::from_ident(ident);
|
|
check_consistency(self, &[seg], ident.span, kind, initial_res, res);
|
|
}
|
|
Err(..) => {
|
|
let expected = kind.descr_expected();
|
|
let msg = format!("cannot find {} `{}` in this scope", expected, ident);
|
|
let mut err = self.session.struct_span_err(ident.span, &msg);
|
|
self.unresolved_macro_suggestions(&mut err, kind, &parent_scope, ident);
|
|
err.emit();
|
|
}
|
|
}
|
|
}
|
|
|
|
let builtin_attrs = mem::take(&mut self.builtin_attrs);
|
|
for (ident, parent_scope) in builtin_attrs {
|
|
let _ = self.early_resolve_ident_in_lexical_scope(
|
|
ident,
|
|
ScopeSet::Macro(MacroKind::Attr),
|
|
&parent_scope,
|
|
true,
|
|
true,
|
|
ident.span,
|
|
);
|
|
}
|
|
}
|
|
|
|
fn check_stability_and_deprecation(
|
|
&mut self,
|
|
ext: &SyntaxExtension,
|
|
path: &ast::Path,
|
|
node_id: NodeId,
|
|
) {
|
|
let span = path.span;
|
|
if let Some(stability) = &ext.stability {
|
|
if let StabilityLevel::Unstable { reason, issue, is_soft } = stability.level {
|
|
let feature = stability.feature;
|
|
if !self.active_features.contains(&feature) && !span.allows_unstable(feature) {
|
|
let lint_buffer = &mut self.lint_buffer;
|
|
let soft_handler =
|
|
|lint, span, msg: &_| lint_buffer.buffer_lint(lint, node_id, span, msg);
|
|
stability::report_unstable(
|
|
self.session,
|
|
feature,
|
|
reason,
|
|
issue,
|
|
is_soft,
|
|
span,
|
|
soft_handler,
|
|
);
|
|
}
|
|
}
|
|
}
|
|
if let Some(depr) = &ext.deprecation {
|
|
let path = pprust::path_to_string(&path);
|
|
let (message, lint) = stability::deprecation_message(depr, "macro", &path);
|
|
stability::early_report_deprecation(
|
|
&mut self.lint_buffer,
|
|
&message,
|
|
depr.suggestion,
|
|
lint,
|
|
span,
|
|
);
|
|
}
|
|
}
|
|
|
|
fn prohibit_imported_non_macro_attrs(
|
|
&self,
|
|
binding: Option<&'a NameBinding<'a>>,
|
|
res: Option<Res>,
|
|
span: Span,
|
|
) {
|
|
if let Some(Res::NonMacroAttr(kind)) = res {
|
|
if kind != NonMacroAttrKind::Tool && binding.map_or(true, |b| b.is_import()) {
|
|
let msg =
|
|
format!("cannot use {} {} through an import", kind.article(), kind.descr());
|
|
let mut err = self.session.struct_span_err(span, &msg);
|
|
if let Some(binding) = binding {
|
|
err.span_note(binding.span, &format!("the {} imported here", kind.descr()));
|
|
}
|
|
err.emit();
|
|
}
|
|
}
|
|
}
|
|
|
|
crate fn check_reserved_macro_name(&mut self, ident: Ident, res: Res) {
|
|
// Reserve some names that are not quite covered by the general check
|
|
// performed on `Resolver::builtin_attrs`.
|
|
if ident.name == sym::cfg || ident.name == sym::cfg_attr || ident.name == sym::derive {
|
|
let macro_kind = self.get_macro(res).map(|ext| ext.macro_kind());
|
|
if macro_kind.is_some() && sub_namespace_match(macro_kind, Some(MacroKind::Attr)) {
|
|
self.session.span_err(
|
|
ident.span,
|
|
&format!("name `{}` is reserved in attribute namespace", ident),
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Compile the macro into a `SyntaxExtension` and possibly replace
|
|
/// its expander to a pre-defined one for built-in macros.
|
|
crate fn compile_macro(&mut self, item: &ast::Item, edition: Edition) -> SyntaxExtension {
|
|
let mut result = compile_declarative_macro(
|
|
&self.session,
|
|
self.session.features_untracked(),
|
|
item,
|
|
edition,
|
|
);
|
|
|
|
if result.is_builtin {
|
|
// The macro was marked with `#[rustc_builtin_macro]`.
|
|
if let Some(builtin_macro) = self.builtin_macros.get_mut(&item.ident.name) {
|
|
// The macro is a built-in, replace its expander function
|
|
// while still taking everything else from the source code.
|
|
// If we already loaded this builtin macro, give a better error message than 'no such builtin macro'.
|
|
match mem::replace(builtin_macro, BuiltinMacroState::AlreadySeen(item.span)) {
|
|
BuiltinMacroState::NotYetSeen(ext) => result.kind = ext.kind,
|
|
BuiltinMacroState::AlreadySeen(span) => {
|
|
struct_span_err!(
|
|
self.session,
|
|
item.span,
|
|
E0773,
|
|
"attempted to define built-in macro more than once"
|
|
)
|
|
.span_note(span, "previously defined here")
|
|
.emit();
|
|
}
|
|
}
|
|
} else {
|
|
let msg = format!("cannot find a built-in macro with name `{}`", item.ident);
|
|
self.session.span_err(item.span, &msg);
|
|
}
|
|
}
|
|
|
|
result
|
|
}
|
|
}
|