//! The core of the module-level name resolution algorithm.
//!
//! `DefCollector::collect` contains the fixed-point iteration loop which
//! resolves imports and expands macros.
use std::iter;
use base_db::{CrateId, Edition, FileId, ProcMacroId};
use cfg::{CfgExpr, CfgOptions};
use hir_expand::{
ast_id_map::FileAstId,
builtin_attr::find_builtin_attr,
builtin_derive::find_builtin_derive,
builtin_macro::find_builtin_macro,
name::{name, AsName, Name},
proc_macro::ProcMacroExpander,
FragmentKind, HirFileId, MacroCallId, MacroCallKind, MacroDefId, MacroDefKind,
};
use hir_expand::{InFile, MacroCallLoc};
use itertools::Itertools;
use la_arena::Idx;
use rustc_hash::{FxHashMap, FxHashSet};
use syntax::ast;
use crate::{
attr::{Attr, AttrId, AttrInput, Attrs},
attr_macro_as_call_id, builtin_attr,
db::DefDatabase,
derive_macro_as_call_id,
intern::Interned,
item_scope::{ImportType, PerNsGlobImports},
item_tree::{
self, Fields, FileItemTreeId, ItemTree, ItemTreeId, MacroCall, MacroDef, MacroRules, Mod,
ModItem, ModKind,
},
macro_call_as_call_id,
nameres::{
diagnostics::DefDiagnostic,
mod_resolution::ModDir,
path_resolution::ReachedFixedPoint,
proc_macro::{ProcMacroDef, ProcMacroKind},
BuiltinShadowMode, DefMap, ModuleData, ModuleOrigin, ResolveMode,
},
path::{ImportAlias, ModPath, PathKind},
per_ns::PerNs,
visibility::{RawVisibility, Visibility},
AdtId, AstId, AstIdWithPath, ConstLoc, EnumLoc, EnumVariantId, FunctionLoc, ImplLoc, Intern,
LocalModuleId, ModuleDefId, StaticLoc, StructLoc, TraitLoc, TypeAliasLoc, UnionLoc,
UnresolvedMacro,
};
const GLOB_RECURSION_LIMIT: usize = 100;
const EXPANSION_DEPTH_LIMIT: usize = 128;
const FIXED_POINT_LIMIT: usize = 8192;
pub(super) fn collect_defs(
db: &dyn DefDatabase,
mut def_map: DefMap,
block: Option<AstId<ast::BlockExpr>>,
) -> DefMap {
let crate_graph = db.crate_graph();
if block.is_none() {
// populate external prelude
for dep in &crate_graph[def_map.krate].dependencies {
log::debug!("crate dep {:?} -> {:?}", dep.name, dep.crate_id);
let dep_def_map = db.crate_def_map(dep.crate_id);
def_map
.extern_prelude
.insert(dep.as_name(), dep_def_map.module_id(dep_def_map.root).into());
}
}
let cfg_options = &crate_graph[def_map.krate].cfg_options;
let proc_macros = &crate_graph[def_map.krate].proc_macro;
let proc_macros = proc_macros
.iter()
.enumerate()
.map(|(idx, it)| {
// FIXME: a hacky way to create a Name from string.
let name = tt::Ident { text: it.name.clone(), id: tt::TokenId::unspecified() };
(name.as_name(), ProcMacroExpander::new(def_map.krate, ProcMacroId(idx as u32)))
})
.collect();
let mut collector = DefCollector {
db,
def_map,
glob_imports: FxHashMap::default(),
unresolved_imports: Vec::new(),
resolved_imports: Vec::new(),
unresolved_macros: Vec::new(),
mod_dirs: FxHashMap::default(),
cfg_options,
proc_macros,
exports_proc_macros: false,
from_glob_import: Default::default(),
skip_attrs: Default::default(),
derive_helpers_in_scope: Default::default(),
registered_attrs: Default::default(),
registered_tools: Default::default(),
};
match block {
Some(block) => {
collector.seed_with_inner(block);
}
None => {
collector.seed_with_top_level();
}
}
collector.collect();
let mut def_map = collector.finish();
def_map.shrink_to_fit();
def_map
}
#[derive(Copy, Clone, Debug, Eq, PartialEq)]
enum PartialResolvedImport {
/// None of any namespaces is resolved
Unresolved,
/// One of namespaces is resolved
Indeterminate(PerNs),
/// All namespaces are resolved, OR it is came from other crate
Resolved(PerNs),
}
impl PartialResolvedImport {
fn namespaces(&self) -> PerNs {
match self {
PartialResolvedImport::Unresolved => PerNs::none(),
PartialResolvedImport::Indeterminate(ns) => *ns,
PartialResolvedImport::Resolved(ns) => *ns,
}
}
}
#[derive(Clone, Debug, Eq, PartialEq)]
enum ImportSource {
Import { id: ItemTreeId<item_tree::Import>, use_tree: Idx<ast::UseTree> },
ExternCrate(ItemTreeId<item_tree::ExternCrate>),
}
#[derive(Clone, Debug, Eq, PartialEq)]
struct Import {
path: Interned<ModPath>,
alias: Option<ImportAlias>,
visibility: RawVisibility,
is_glob: bool,
is_prelude: bool,
is_extern_crate: bool,
is_macro_use: bool,
source: ImportSource,
}
impl Import {
fn from_use(
db: &dyn DefDatabase,
krate: CrateId,
tree: &ItemTree,
id: ItemTreeId<item_tree::Import>,
) -> Vec<Self> {
let it = &tree[id.value];
let attrs = &tree.attrs(db, krate, ModItem::from(id.value).into());
let visibility = &tree[it.visibility];
let is_prelude = attrs.by_key("prelude_import").exists();
let mut res = Vec::new();
it.use_tree.expand(|idx, path, is_glob, alias| {
res.push(Self {
path: Interned::new(path), // FIXME this makes little sense
alias,
visibility: visibility.clone(),
is_glob,
is_prelude,
is_extern_crate: false,
is_macro_use: false,
source: ImportSource::Import { id, use_tree: idx },
});
});
res
}
fn from_extern_crate(
db: &dyn DefDatabase,
krate: CrateId,
tree: &ItemTree,
id: ItemTreeId<item_tree::ExternCrate>,
) -> Self {
let it = &tree[id.value];
let attrs = &tree.attrs(db, krate, ModItem::from(id.value).into());
let visibility = &tree[it.visibility];
Self {
path: Interned::new(ModPath::from_segments(
PathKind::Plain,
iter::once(it.name.clone()),
)),
alias: it.alias.clone(),
visibility: visibility.clone(),
is_glob: false,
is_prelude: false,
is_extern_crate: true,
is_macro_use: attrs.by_key("macro_use").exists(),
source: ImportSource::ExternCrate(id),
}
}
}
#[derive(Clone, Debug, Eq, PartialEq)]
struct ImportDirective {
module_id: LocalModuleId,
import: Import,
status: PartialResolvedImport,
}
#[derive(Clone, Debug, Eq, PartialEq)]
struct MacroDirective {
module_id: LocalModuleId,
depth: usize,
kind: MacroDirectiveKind,
}
#[derive(Clone, Debug, Eq, PartialEq)]
enum MacroDirectiveKind {
FnLike { ast_id: AstIdWithPath<ast::MacroCall>, fragment: FragmentKind },
Derive { ast_id: AstIdWithPath<ast::Item>, derive_attr: AttrId },
Attr { ast_id: AstIdWithPath<ast::Item>, attr: Attr, mod_item: ModItem },
}
struct DefData<'a> {
id: ModuleDefId,
name: &'a Name,
visibility: &'a RawVisibility,
has_constructor: bool,
}
/// Walks the tree of module recursively
struct DefCollector<'a> {
db: &'a dyn DefDatabase,
def_map: DefMap,
glob_imports: FxHashMap<LocalModuleId, Vec<(LocalModuleId, Visibility)>>,
unresolved_imports: Vec<ImportDirective>,
resolved_imports: Vec<ImportDirective>,
unresolved_macros: Vec<MacroDirective>,
mod_dirs: FxHashMap<LocalModuleId, ModDir>,
cfg_options: &'a CfgOptions,
/// List of procedural macros defined by this crate. This is read from the dynamic library
/// built by the build system, and is the list of proc. macros we can actually expand. It is
/// empty when proc. macro support is disabled (in which case we still do name resolution for
/// them).
proc_macros: Vec<(Name, ProcMacroExpander)>,
exports_proc_macros: bool,
from_glob_import: PerNsGlobImports,
/// If we fail to resolve an attribute on a `ModItem`, we fall back to ignoring the attribute.
/// This map is used to skip all attributes up to and including the one that failed to resolve,
/// in order to not expand them twice.
///
/// This also stores the attributes to skip when we resolve derive helpers and non-macro
/// non-builtin attributes in general.
skip_attrs: FxHashMap<InFile<ModItem>, AttrId>,
/// Tracks which custom derives are in scope for an item, to allow resolution of derive helper
/// attributes.
derive_helpers_in_scope: FxHashMap<AstId<ast::Item>, Vec<Name>>,
/// Custom attributes registered with `#![register_attr]`.
registered_attrs: Vec<String>,
/// Custom tool modules registered with `#![register_tool]`.
registered_tools: Vec<String>,
}
impl DefCollector<'_> {
fn seed_with_top_level(&mut self) {
let file_id = self.db.crate_graph()[self.def_map.krate].root_file_id;
let item_tree = self.db.file_item_tree(file_id.into());
let module_id = self.def_map.root;
self.def_map.modules[module_id].origin = ModuleOrigin::CrateRoot { definition: file_id };
let attrs = item_tree.top_level_attrs(self.db, self.def_map.krate);
if attrs.cfg().map_or(true, |cfg| self.cfg_options.check(&cfg) != Some(false)) {
self.inject_prelude(&attrs);
// Process other crate-level attributes.
for attr in &*attrs {
let attr_name = match attr.path.as_ident() {
Some(name) => name,
None => continue,
};
let registered_name = if *attr_name == hir_expand::name![register_attr]
|| *attr_name == hir_expand::name![register_tool]
{
match attr.input.as_deref() {
Some(AttrInput::TokenTree(subtree)) => match &*subtree.token_trees {
[tt::TokenTree::Leaf(tt::Leaf::Ident(name))] => name.as_name(),
_ => continue,
},
_ => continue,
}
} else {
continue;
};
if *attr_name == hir_expand::name![register_attr] {
self.registered_attrs.push(registered_name.to_string());
cov_mark::hit!(register_attr);
} else {
self.registered_tools.push(registered_name.to_string());
cov_mark::hit!(register_tool);
}
}
ModCollector {
def_collector: &mut *self,
macro_depth: 0,
module_id,
file_id: file_id.into(),
item_tree: &item_tree,
mod_dir: ModDir::root(),
}
.collect(item_tree.top_level_items());
}
}
fn seed_with_inner(&mut self, block: AstId<ast::BlockExpr>) {
let item_tree = self.db.file_item_tree(block.file_id);
let module_id = self.def_map.root;
self.def_map.modules[module_id].origin = ModuleOrigin::BlockExpr { block };
if item_tree
.top_level_attrs(self.db, self.def_map.krate)
.cfg()
.map_or(true, |cfg| self.cfg_options.check(&cfg) != Some(false))
{
ModCollector {
def_collector: &mut *self,
macro_depth: 0,
module_id,
file_id: block.file_id,
item_tree: &item_tree,
mod_dir: ModDir::root(),
}
.collect(item_tree.inner_items_of_block(block.value));
}
}
fn collect(&mut self) {
// main name resolution fixed-point loop.
let mut i = 0;
'outer: loop {
loop {
self.db.unwind_if_cancelled();
loop {
if self.resolve_imports() == ReachedFixedPoint::Yes {
break;
}
}
if self.resolve_macros() == ReachedFixedPoint::Yes {
break;
}
i += 1;
if i == FIXED_POINT_LIMIT {
log::error!("name resolution is stuck");
break 'outer;
}
}
if self.reseed_with_unresolved_attribute() == ReachedFixedPoint::Yes {
break;
}
}
// Resolve all indeterminate resolved imports again
// As some of the macros will expand newly import shadowing partial resolved imports
// FIXME: We maybe could skip this, if we handle the indeterminate imports in `resolve_imports`
// correctly
let partial_resolved = self.resolved_imports.iter().filter_map(|directive| {
if let PartialResolvedImport::Indeterminate(_) = directive.status {
let mut directive = directive.clone();
directive.status = PartialResolvedImport::Unresolved;
Some(directive)
} else {
None
}
});
self.unresolved_imports.extend(partial_resolved);
self.resolve_imports();
let unresolved_imports = std::mem::replace(&mut self.unresolved_imports, Vec::new());
// show unresolved imports in completion, etc
for directive in &unresolved_imports {
self.record_resolved_import(directive)
}
self.unresolved_imports = unresolved_imports;
// FIXME: This condition should instead check if this is a `proc-macro` type crate.
if self.exports_proc_macros {
// A crate exporting procedural macros is not allowed to export anything else.
//
// Additionally, while the proc macro entry points must be `pub`, they are not publicly
// exported in type/value namespace. This function reduces the visibility of all items
// in the crate root that aren't proc macros.
let root = self.def_map.root;
let module_id = self.def_map.module_id(root);
let root = &mut self.def_map.modules[root];
root.scope.censor_non_proc_macros(module_id);
}
}
/// When the fixed-point loop reaches a stable state, we might still have some unresolved
/// attributes (or unexpanded attribute proc macros) left over. This takes one of them, and
/// feeds the item it's applied to back into name resolution.
///
/// This effectively ignores the fact that the macro is there and just treats the items as
/// normal code.
///
/// This improves UX when proc macros are turned off or don't work, and replicates the behavior
/// before we supported proc. attribute macros.
fn reseed_with_unresolved_attribute(&mut self) -> ReachedFixedPoint {
cov_mark::hit!(unresolved_attribute_fallback);
let mut unresolved_macros = std::mem::replace(&mut self.unresolved_macros, Vec::new());
let pos = unresolved_macros.iter().position(|directive| {
if let MacroDirectiveKind::Attr { ast_id, mod_item, attr } = &directive.kind {
self.skip_attrs.insert(ast_id.ast_id.with_value(*mod_item), attr.id);
let file_id = ast_id.ast_id.file_id;
let item_tree = self.db.file_item_tree(file_id);
let mod_dir = self.mod_dirs[&directive.module_id].clone();
ModCollector {
def_collector: &mut *self,
macro_depth: directive.depth,
module_id: directive.module_id,
file_id,
item_tree: &item_tree,
mod_dir,
}
.collect(&[*mod_item]);
true
} else {
false
}
});
if let Some(pos) = pos {
unresolved_macros.remove(pos);
}
// The collection above might add new unresolved macros (eg. derives), so merge the lists.
self.unresolved_macros.extend(unresolved_macros);
if pos.is_some() {
// Continue name resolution with the new data.
ReachedFixedPoint::No
} else {
ReachedFixedPoint::Yes
}
}
fn inject_prelude(&mut self, crate_attrs: &Attrs) {
// See compiler/rustc_builtin_macros/src/standard_library_imports.rs
if crate_attrs.by_key("no_core").exists() {
// libcore does not get a prelude.
return;
}
let krate = if crate_attrs.by_key("no_std").exists() {
name![core]
} else {
let std = name![std];
if self.def_map.extern_prelude().any(|(name, _)| *name == std) {
std
} else {
// If `std` does not exist for some reason, fall back to core. This mostly helps
// keep r-a's own tests minimal.
name![core]
}
};
let edition = match self.def_map.edition {
Edition::Edition2015 => name![rust_2015],
Edition::Edition2018 => name![rust_2018],
Edition::Edition2021 => name![rust_2021],
};
let path_kind = if self.def_map.edition == Edition::Edition2015 {
PathKind::Plain
} else {
PathKind::Abs
};
let path = ModPath::from_segments(
path_kind.clone(),
[krate.clone(), name![prelude], edition].iter().cloned(),
);
// Fall back to the older `std::prelude::v1` for compatibility with Rust <1.52.0
// FIXME remove this fallback
let fallback_path =
ModPath::from_segments(path_kind, [krate, name![prelude], name![v1]].iter().cloned());
for path in &[path, fallback_path] {
let (per_ns, _) = self.def_map.resolve_path(
self.db,
self.def_map.root,
path,
BuiltinShadowMode::Other,
);
match &per_ns.types {
Some((ModuleDefId::ModuleId(m), _)) => {
self.def_map.prelude = Some(*m);
return;
}
_ => {
log::debug!(
"could not resolve prelude path `{}` to module (resolved to {:?})",
path,
per_ns.types
);
}
}
}
}
/// Adds a definition of procedural macro `name` to the root module.
///
/// # Notes on procedural macro resolution
///
/// Procedural macro functionality is provided by the build system: It has to build the proc
/// macro and pass the resulting dynamic library to rust-analyzer.
///
/// When procedural macro support is enabled, the list of proc macros exported by a crate is
/// known before we resolve names in the crate. This list is stored in `self.proc_macros` and is
/// derived from the dynamic library.
///
/// However, we *also* would like to be able to at least *resolve* macros on our own, without
/// help by the build system. So, when the macro isn't found in `self.proc_macros`, we instead
/// use a dummy expander that always errors. This comes with the drawback of macros potentially
/// going out of sync with what the build system sees (since we resolve using VFS state, but
/// Cargo builds only on-disk files). We could and probably should add diagnostics for that.
fn export_proc_macro(&mut self, def: ProcMacroDef, ast_id: AstId<ast::Fn>) {
let kind = def.kind.to_basedb_kind();
self.exports_proc_macros = true;
let macro_def = match self.proc_macros.iter().find(|(n, _)| n == &def.name) {
Some((_, expander)) => MacroDefId {
krate: self.def_map.krate,
kind: MacroDefKind::ProcMacro(*expander, kind, ast_id),
local_inner: false,
},
None => MacroDefId {
krate: self.def_map.krate,
kind: MacroDefKind::ProcMacro(
ProcMacroExpander::dummy(self.def_map.krate),
kind,
ast_id,
),
local_inner: false,
},
};
self.define_proc_macro(def.name.clone(), macro_def);
self.def_map.exported_proc_macros.insert(macro_def, def);
}
/// Define a macro with `macro_rules`.
///
/// It will define the macro in legacy textual scope, and if it has `#[macro_export]`,
/// then it is also defined in the root module scope.
/// You can `use` or invoke it by `crate::macro_name` anywhere, before or after the definition.
///
/// It is surprising that the macro will never be in the current module scope.
/// These code fails with "unresolved import/macro",
/// ```rust,compile_fail
/// mod m { macro_rules! foo { () => {} } }
/// use m::foo as bar;
/// ```
///
/// ```rust,compile_fail
/// macro_rules! foo { () => {} }
/// self::foo!();
/// crate::foo!();
/// ```
///
/// Well, this code compiles, because the plain path `foo` in `use` is searched
/// in the legacy textual scope only.
/// ```rust
/// macro_rules! foo { () => {} }
/// use foo as bar;
/// ```
fn define_macro_rules(
&mut self,
module_id: LocalModuleId,
name: Name,
macro_: MacroDefId,
export: bool,
) {
// Textual scoping
self.define_legacy_macro(module_id, name.clone(), macro_);
// Module scoping
// In Rust, `#[macro_export]` macros are unconditionally visible at the
// crate root, even if the parent modules is **not** visible.
if export {
self.update(
self.def_map.root,
&[(Some(name), PerNs::macros(macro_, Visibility::Public))],
Visibility::Public,
ImportType::Named,
);
}
}
/// Define a legacy textual scoped macro in module
///
/// We use a map `legacy_macros` to store all legacy textual scoped macros visible per module.
/// It will clone all macros from parent legacy scope, whose definition is prior to
/// the definition of current module.
/// And also, `macro_use` on a module will import all legacy macros visible inside to
/// current legacy scope, with possible shadowing.
fn define_legacy_macro(&mut self, module_id: LocalModuleId, name: Name, mac: MacroDefId) {
// Always shadowing
self.def_map.modules[module_id].scope.define_legacy_macro(name, mac);
}
/// Define a macro 2.0 macro
///
/// The scoped of macro 2.0 macro is equal to normal function
fn define_macro_def(
&mut self,
module_id: LocalModuleId,
name: Name,
macro_: MacroDefId,
vis: &RawVisibility,
) {
let vis =
self.def_map.resolve_visibility(self.db, module_id, vis).unwrap_or(Visibility::Public);
self.update(module_id, &[(Some(name), PerNs::macros(macro_, vis))], vis, ImportType::Named);
}
/// Define a proc macro
///
/// A proc macro is similar to normal macro scope, but it would not visible in legacy textual scoped.
/// And unconditionally exported.
fn define_proc_macro(&mut self, name: Name, macro_: MacroDefId) {
self.update(
self.def_map.root,
&[(Some(name), PerNs::macros(macro_, Visibility::Public))],
Visibility::Public,
ImportType::Named,
);
}
/// Import macros from `#[macro_use] extern crate`.
fn import_macros_from_extern_crate(
&mut self,
current_module_id: LocalModuleId,
extern_crate: &item_tree::ExternCrate,
) {
log::debug!(
"importing macros from extern crate: {:?} ({:?})",
extern_crate,
self.def_map.edition,
);
let res = self.def_map.resolve_name_in_extern_prelude(self.db, &extern_crate.name);
if let Some(ModuleDefId::ModuleId(m)) = res.take_types() {
if m == self.def_map.module_id(current_module_id) {
cov_mark::hit!(ignore_macro_use_extern_crate_self);
return;
}
cov_mark::hit!(macro_rules_from_other_crates_are_visible_with_macro_use);
self.import_all_macros_exported(current_module_id, m.krate);
}
}
/// Import all exported macros from another crate
///
/// Exported macros are just all macros in the root module scope.
/// Note that it contains not only all `#[macro_export]` macros, but also all aliases
/// created by `use` in the root module, ignoring the visibility of `use`.
fn import_all_macros_exported(&mut self, current_module_id: LocalModuleId, krate: CrateId) {
let def_map = self.db.crate_def_map(krate);
for (name, def) in def_map[def_map.root].scope.macros() {
// `macro_use` only bring things into legacy scope.
self.define_legacy_macro(current_module_id, name.clone(), def);
}
}
/// Tries to resolve every currently unresolved import.
fn resolve_imports(&mut self) -> ReachedFixedPoint {
let mut res = ReachedFixedPoint::Yes;
let imports = std::mem::replace(&mut self.unresolved_imports, Vec::new());
let imports = imports
.into_iter()
.filter_map(|mut directive| {
directive.status = self.resolve_import(directive.module_id, &directive.import);
match directive.status {
PartialResolvedImport::Indeterminate(_) => {
self.record_resolved_import(&directive);
// FIXME: For avoid performance regression,
// we consider an imported resolved if it is indeterminate (i.e not all namespace resolved)
self.resolved_imports.push(directive);
res = ReachedFixedPoint::No;
None
}
PartialResolvedImport::Resolved(_) => {
self.record_resolved_import(&directive);
self.resolved_imports.push(directive);
res = ReachedFixedPoint::No;
None
}
PartialResolvedImport::Unresolved => Some(directive),
}
})
.collect();
self.unresolved_imports = imports;
res
}
fn resolve_import(&self, module_id: LocalModuleId, import: &Import) -> PartialResolvedImport {
log::debug!("resolving import: {:?} ({:?})", import, self.def_map.edition);
if import.is_extern_crate {
let res = self.def_map.resolve_name_in_extern_prelude(
self.db,
import
.path
.as_ident()
.expect("extern crate should have been desugared to one-element path"),
);
if res.is_none() {
PartialResolvedImport::Unresolved
} else {
PartialResolvedImport::Resolved(res)
}
} else {
let res = self.def_map.resolve_path_fp_with_macro(
self.db,
ResolveMode::Import,
module_id,
&import.path,
BuiltinShadowMode::Module,
);
let def = res.resolved_def;
if res.reached_fixedpoint == ReachedFixedPoint::No || def.is_none() {
return PartialResolvedImport::Unresolved;
}
if let Some(krate) = res.krate {
if krate != self.def_map.krate {
return PartialResolvedImport::Resolved(def);
}
}
// Check whether all namespace is resolved
if def.take_types().is_some()
&& def.take_values().is_some()
&& def.take_macros().is_some()
{
PartialResolvedImport::Resolved(def)
} else {
PartialResolvedImport::Indeterminate(def)
}
}
}
fn record_resolved_import(&mut self, directive: &ImportDirective) {
let module_id = directive.module_id;
let import = &directive.import;
let def = directive.status.namespaces();
let vis = self
.def_map
.resolve_visibility(self.db, module_id, &directive.import.visibility)
.unwrap_or(Visibility::Public);
if import.is_glob {
log::debug!("glob import: {:?}", import);
match def.take_types() {
Some(ModuleDefId::ModuleId(m)) => {
if import.is_prelude {
// Note: This dodgily overrides the injected prelude. The rustc
// implementation seems to work the same though.
cov_mark::hit!(std_prelude);
self.def_map.prelude = Some(m);
} else if m.krate != self.def_map.krate {
cov_mark::hit!(glob_across_crates);
// glob import from other crate => we can just import everything once
let item_map = m.def_map(self.db);
let scope = &item_map[m.local_id].scope;
// Module scoped macros is included
let items = scope
.resolutions()
// only keep visible names...
.map(|(n, res)| {
(n, res.filter_visibility(|v| v.is_visible_from_other_crate()))
})
.filter(|(_, res)| !res.is_none())
.collect::<Vec<_>>();
self.update(module_id, &items, vis, ImportType::Glob);
} else {
// glob import from same crate => we do an initial
// import, and then need to propagate any further
// additions
let def_map;
let scope = if m.block == self.def_map.block_id() {
&self.def_map[m.local_id].scope
} else {
def_map = m.def_map(self.db);
&def_map[m.local_id].scope
};
// Module scoped macros is included
let items = scope
.resolutions()
// only keep visible names...
.map(|(n, res)| {
(
n,
res.filter_visibility(|v| {
v.is_visible_from_def_map(self.db, &self.def_map, module_id)
}),
)
})
.filter(|(_, res)| !res.is_none())
.collect::<Vec<_>>();
self.update(module_id, &items, vis, ImportType::Glob);
// record the glob import in case we add further items
let glob = self.glob_imports.entry(m.local_id).or_default();
if !glob.iter().any(|(mid, _)| *mid == module_id) {
glob.push((module_id, vis));
}
}
}
Some(ModuleDefId::AdtId(AdtId::EnumId(e))) => {
cov_mark::hit!(glob_enum);
// glob import from enum => just import all the variants
// XXX: urgh, so this works by accident! Here, we look at
// the enum data, and, in theory, this might require us to
// look back at the crate_def_map, creating a cycle. For
// example, `enum E { crate::some_macro!(); }`. Luckily, the
// only kind of macro that is allowed inside enum is a
// `cfg_macro`, and we don't need to run name resolution for
// it, but this is sheer luck!
let enum_data = self.db.enum_data(e);
let resolutions = enum_data
.variants
.iter()
.map(|(local_id, variant_data)| {
let name = variant_data.name.clone();
let variant = EnumVariantId { parent: e, local_id };
let res = PerNs::both(variant.into(), variant.into(), vis);
(Some(name), res)
})
.collect::<Vec<_>>();
self.update(module_id, &resolutions, vis, ImportType::Glob);
}
Some(d) => {
log::debug!("glob import {:?} from non-module/enum {:?}", import, d);
}
None => {
log::debug!("glob import {:?} didn't resolve as type", import);
}
}
} else {
let name = match &import.alias {
Some(ImportAlias::Alias(name)) => Some(name.clone()),
Some(ImportAlias::Underscore) => None,
None => match import.path.segments().last() {
Some(last_segment) => Some(last_segment.clone()),
None => {
cov_mark::hit!(bogus_paths);
return;
}
},
};
log::debug!("resolved import {:?} ({:?}) to {:?}", name, import, def);
// extern crates in the crate root are special-cased to insert entries into the extern prelude: rust-lang/rust#54658
if import.is_extern_crate && module_id == self.def_map.root {
if let (Some(def), Some(name)) = (def.take_types(), name.as_ref()) {
self.def_map.extern_prelude.insert(name.clone(), def);
}
}
self.update(module_id, &[(name, def)], vis, ImportType::Named);
}
}
fn update(
&mut self,
module_id: LocalModuleId,
resolutions: &[(Option<Name>, PerNs)],
vis: Visibility,
import_type: ImportType,
) {
self.db.unwind_if_cancelled();
self.update_recursive(module_id, resolutions, vis, import_type, 0)
}
fn update_recursive(
&mut self,
module_id: LocalModuleId,
resolutions: &[(Option<Name>, PerNs)],
// All resolutions are imported with this visibility; the visibilities in
// the `PerNs` values are ignored and overwritten
vis: Visibility,
import_type: ImportType,
depth: usize,
) {
if depth > GLOB_RECURSION_LIMIT {
// prevent stack overflows (but this shouldn't be possible)
panic!("infinite recursion in glob imports!");
}
let mut changed = false;
for (name, res) in resolutions {
match name {
Some(name) => {
let scope = &mut self.def_map.modules[module_id].scope;
changed |= scope.push_res_with_import(
&mut self.from_glob_import,
(module_id, name.clone()),
res.with_visibility(vis),
import_type,
);
}
None => {
let tr = match res.take_types() {
Some(ModuleDefId::TraitId(tr)) => tr,
Some(other) => {
log::debug!("non-trait `_` import of {:?}", other);
continue;
}
None => continue,
};
let old_vis = self.def_map.modules[module_id].scope.unnamed_trait_vis(tr);
let should_update = match old_vis {
None => true,
Some(old_vis) => {
let max_vis = old_vis.max(vis, &self.def_map).unwrap_or_else(|| {
panic!("`Tr as _` imports with unrelated visibilities {:?} and {:?} (trait {:?})", old_vis, vis, tr);
});
if max_vis == old_vis {
false
} else {
cov_mark::hit!(upgrade_underscore_visibility);
true
}
}
};
if should_update {
changed = true;
self.def_map.modules[module_id].scope.push_unnamed_trait(tr, vis);
}
}
}
}
if !changed {
return;
}
let glob_imports = self
.glob_imports
.get(&module_id)
.into_iter()
.flat_map(|v| v.iter())
.filter(|(glob_importing_module, _)| {
// we know all resolutions have the same visibility (`vis`), so we
// just need to check that once
vis.is_visible_from_def_map(self.db, &self.def_map, *glob_importing_module)
})
.cloned()
.collect::<Vec<_>>();
for (glob_importing_module, glob_import_vis) in glob_imports {
self.update_recursive(
glob_importing_module,
resolutions,
glob_import_vis,
ImportType::Glob,
depth + 1,
);
}
}
fn resolve_macros(&mut self) -> ReachedFixedPoint {
let mut macros = std::mem::replace(&mut self.unresolved_macros, Vec::new());
let mut resolved = Vec::new();
let mut res = ReachedFixedPoint::Yes;
macros.retain(|directive| {
let resolver = |path| {
let resolved_res = self.def_map.resolve_path_fp_with_macro(
self.db,
ResolveMode::Other,
directive.module_id,
&path,
BuiltinShadowMode::Module,
);
resolved_res.resolved_def.take_macros()
};
match &directive.kind {
MacroDirectiveKind::FnLike { ast_id, fragment } => {
match macro_call_as_call_id(
ast_id,
*fragment,
self.db,
self.def_map.krate,
&resolver,
&mut |_err| (),
) {
Ok(Ok(call_id)) => {
resolved.push((directive.module_id, call_id, directive.depth));
res = ReachedFixedPoint::No;
return false;
}
Err(UnresolvedMacro { .. }) | Ok(Err(_)) => {}
}
}
MacroDirectiveKind::Derive { ast_id, derive_attr } => {
match derive_macro_as_call_id(
ast_id,
*derive_attr,
self.db,
self.def_map.krate,
&resolver,
) {
Ok(call_id) => {
resolved.push((directive.module_id, call_id, directive.depth));
res = ReachedFixedPoint::No;
return false;
}
Err(UnresolvedMacro { .. }) => (),
}
}
MacroDirectiveKind::Attr { ast_id, mod_item, attr } => {
if let Some(ident) = ast_id.path.as_ident() {
if let Some(helpers) = self.derive_helpers_in_scope.get(&ast_id.ast_id) {
if helpers.contains(ident) {
cov_mark::hit!(resolved_derive_helper);
// Resolved to derive helper. Collect the item's attributes again,
// starting after the derive helper.
let file_id = ast_id.ast_id.file_id;
let item_tree = self.db.file_item_tree(file_id);
let mod_dir = self.mod_dirs[&directive.module_id].clone();
self.skip_attrs.insert(InFile::new(file_id, *mod_item), attr.id);
ModCollector {
def_collector: &mut *self,
macro_depth: directive.depth,
module_id: directive.module_id,
file_id,
item_tree: &item_tree,
mod_dir,
}
.collect(&[*mod_item]);
// Remove the original directive since we resolved it.
res = ReachedFixedPoint::No;
return false;
}
}
}
if !self.db.enable_proc_attr_macros() {
return true;
}
// Not resolved to a derive helper, so try to resolve as a macro.
match attr_macro_as_call_id(
ast_id,
attr,
self.db,
self.def_map.krate,
&resolver,
) {
Ok(call_id) => {
let loc: MacroCallLoc = self.db.lookup_intern_macro(call_id);
if let MacroDefKind::ProcMacro(exp, ..) = &loc.def.kind {
if exp.is_dummy() {
// Proc macros that cannot be expanded are treated as not
// resolved, in order to fall back later.
self.def_map.diagnostics.push(
DefDiagnostic::unresolved_proc_macro(
directive.module_id,
loc.kind,
),
);
let file_id = ast_id.ast_id.file_id;
let item_tree = self.db.file_item_tree(file_id);
let mod_dir = self.mod_dirs[&directive.module_id].clone();
self.skip_attrs
.insert(InFile::new(file_id, *mod_item), attr.id);
ModCollector {
def_collector: &mut *self,
macro_depth: directive.depth,
module_id: directive.module_id,
file_id,
item_tree: &item_tree,
mod_dir,
}
.collect(&[*mod_item]);
// Remove the macro directive.
return false;
}
}
self.def_map.modules[directive.module_id]
.scope
.add_attr_macro_invoc(ast_id.ast_id, call_id);
resolved.push((directive.module_id, call_id, directive.depth));
res = ReachedFixedPoint::No;
return false;
}
Err(UnresolvedMacro { .. }) => (),
}
}
}
true
});
// Attribute resolution can add unresolved macro invocations, so concatenate the lists.
self.unresolved_macros.extend(macros);
for (module_id, macro_call_id, depth) in resolved {
self.collect_macro_expansion(module_id, macro_call_id, depth);
}
res
}
fn collect_macro_expansion(
&mut self,
module_id: LocalModuleId,
macro_call_id: MacroCallId,
depth: usize,
) {
if depth > EXPANSION_DEPTH_LIMIT {
cov_mark::hit!(macro_expansion_overflow);
log::warn!("macro expansion is too deep");
return;
}
let file_id = macro_call_id.as_file();
// First, fetch the raw expansion result for purposes of error reporting. This goes through
// `macro_expand_error` to avoid depending on the full expansion result (to improve
// incrementality).
let loc: MacroCallLoc = self.db.lookup_intern_macro(macro_call_id);
let err = self.db.macro_expand_error(macro_call_id);
if let Some(err) = err {
let diag = match err {
hir_expand::ExpandError::UnresolvedProcMacro => {
// Missing proc macros are non-fatal, so they are handled specially.
DefDiagnostic::unresolved_proc_macro(module_id, loc.kind.clone())
}
_ => DefDiagnostic::macro_error(module_id, loc.kind.clone(), err.to_string()),
};
self.def_map.diagnostics.push(diag);
}
// If we've just resolved a derive, record its helper attributes.
if let MacroCallKind::Derive { ast_id, .. } = &loc.kind {
if loc.def.krate != self.def_map.krate {
let def_map = self.db.crate_def_map(loc.def.krate);
if let Some(def) = def_map.exported_proc_macros.get(&loc.def) {
if let ProcMacroKind::CustomDerive { helpers } = &def.kind {
self.derive_helpers_in_scope
.entry(*ast_id)
.or_default()
.extend(helpers.iter().cloned());
}
}
}
}
// Then, fetch and process the item tree. This will reuse the expansion result from above.
let item_tree = self.db.file_item_tree(file_id);
let mod_dir = self.mod_dirs[&module_id].clone();
ModCollector {
def_collector: &mut *self,
macro_depth: depth,
file_id,
module_id,
item_tree: &item_tree,
mod_dir,
}
.collect(item_tree.top_level_items());
}
fn finish(mut self) -> DefMap {
// Emit diagnostics for all remaining unexpanded macros.
for directive in &self.unresolved_macros {
match &directive.kind {
MacroDirectiveKind::FnLike { ast_id, fragment } => match macro_call_as_call_id(
ast_id,
*fragment,
self.db,
self.def_map.krate,
|path| {
let resolved_res = self.def_map.resolve_path_fp_with_macro(
self.db,
ResolveMode::Other,
directive.module_id,
&path,
BuiltinShadowMode::Module,
);
resolved_res.resolved_def.take_macros()
},
&mut |_| (),
) {
Ok(_) => (),
Err(UnresolvedMacro { path }) => {
self.def_map.diagnostics.push(DefDiagnostic::unresolved_macro_call(
directive.module_id,
ast_id.ast_id,
path,
));
}
},
MacroDirectiveKind::Derive { .. } | MacroDirectiveKind::Attr { .. } => {
// FIXME: we might want to diagnose this too
}
}
}
// Emit diagnostics for all remaining unresolved imports.
// We'd like to avoid emitting a diagnostics avalanche when some `extern crate` doesn't
// resolve. We first emit diagnostics for unresolved extern crates and collect the missing
// crate names. Then we emit diagnostics for unresolved imports, but only if the import
// doesn't start with an unresolved crate's name. Due to renaming and reexports, this is a
// heuristic, but it works in practice.
let mut diagnosed_extern_crates = FxHashSet::default();
for directive in &self.unresolved_imports {
if let ImportSource::ExternCrate(krate) = directive.import.source {
let item_tree = krate.item_tree(self.db);
let extern_crate = &item_tree[krate.value];
diagnosed_extern_crates.insert(extern_crate.name.clone());
self.def_map.diagnostics.push(DefDiagnostic::unresolved_extern_crate(
directive.module_id,
InFile::new(krate.file_id(), extern_crate.ast_id),
));
}
}
for directive in &self.unresolved_imports {
if let ImportSource::Import { id: import, use_tree } = &directive.import.source {
match (directive.import.path.segments().first(), &directive.import.path.kind) {
(Some(krate), PathKind::Plain | PathKind::Abs) => {
if diagnosed_extern_crates.contains(krate) {
continue;
}
}
_ => {}
}
self.def_map.diagnostics.push(DefDiagnostic::unresolved_import(
directive.module_id,
*import,
*use_tree,
));
}
}
self.def_map
}
}
/// Walks a single module, populating defs, imports and macros
struct ModCollector<'a, 'b> {
def_collector: &'a mut DefCollector<'b>,
macro_depth: usize,
module_id: LocalModuleId,
file_id: HirFileId,
item_tree: &'a ItemTree,
mod_dir: ModDir,
}
impl ModCollector<'_, '_> {
fn collect(&mut self, items: &[ModItem]) {
let krate = self.def_collector.def_map.krate;
// Note: don't assert that inserted value is fresh: it's simply not true
// for macros.
self.def_collector.mod_dirs.insert(self.module_id, self.mod_dir.clone());
// Prelude module is always considered to be `#[macro_use]`.
if let Some(prelude_module) = self.def_collector.def_map.prelude {
if prelude_module.krate != krate {
cov_mark::hit!(prelude_is_macro_use);
self.def_collector.import_all_macros_exported(self.module_id, prelude_module.krate);
}
}
// This should be processed eagerly instead of deferred to resolving.
// `#[macro_use] extern crate` is hoisted to imports macros before collecting
// any other items.
for item in items {
let attrs = self.item_tree.attrs(self.def_collector.db, krate, (*item).into());
if attrs.cfg().map_or(true, |cfg| self.is_cfg_enabled(&cfg)) {
if let ModItem::ExternCrate(id) = item {
let import = self.item_tree[*id].clone();
let attrs = self.item_tree.attrs(
self.def_collector.db,
krate,
ModItem::from(*id).into(),
);
if attrs.by_key("macro_use").exists() {
self.def_collector.import_macros_from_extern_crate(self.module_id, &import);
}
}
}
}
for &item in items {
let attrs = self.item_tree.attrs(self.def_collector.db, krate, item.into());
if let Some(cfg) = attrs.cfg() {
if !self.is_cfg_enabled(&cfg) {
self.emit_unconfigured_diagnostic(item, &cfg);
continue;
}
}
if let Err(()) = self.resolve_attributes(&attrs, item) {
// Do not process the item. It has at least one non-builtin attribute, so the
// fixed-point algorithm is required to resolve the rest of them.
continue;
}
let module = self.def_collector.def_map.module_id(self.module_id);
let mut def = None;
match item {
ModItem::Mod(m) => self.collect_module(&self.item_tree[m], &attrs),
ModItem::Import(import_id) => {
let module_id = self.module_id;
let imports = Import::from_use(
self.def_collector.db,
krate,
self.item_tree,
ItemTreeId::new(self.file_id, import_id),
);
self.def_collector.unresolved_imports.extend(imports.into_iter().map(
|import| ImportDirective {
module_id,
import,
status: PartialResolvedImport::Unresolved,
},
));
}
ModItem::ExternCrate(import_id) => {
self.def_collector.unresolved_imports.push(ImportDirective {
module_id: self.module_id,
import: Import::from_extern_crate(
self.def_collector.db,
krate,
self.item_tree,
ItemTreeId::new(self.file_id, import_id),
),
status: PartialResolvedImport::Unresolved,
})
}
ModItem::ExternBlock(block) => self.collect(&self.item_tree[block].children),
ModItem::MacroCall(mac) => self.collect_macro_call(&self.item_tree[mac]),
ModItem::MacroRules(id) => self.collect_macro_rules(id),
ModItem::MacroDef(id) => self.collect_macro_def(id),
ModItem::Impl(imp) => {
let module = self.def_collector.def_map.module_id(self.module_id);
let impl_id =
ImplLoc { container: module, id: ItemTreeId::new(self.file_id, imp) }
.intern(self.def_collector.db);
self.def_collector.def_map.modules[self.module_id].scope.define_impl(impl_id)
}
ModItem::Function(id) => {
let func = &self.item_tree[id];
let ast_id = InFile::new(self.file_id, func.ast_id);
self.collect_proc_macro_def(&func.name, ast_id, &attrs);
def = Some(DefData {
id: FunctionLoc {
container: module.into(),
id: ItemTreeId::new(self.file_id, id),
}
.intern(self.def_collector.db)
.into(),
name: &func.name,
visibility: &self.item_tree[func.visibility],
has_constructor: false,
});
}
ModItem::Struct(id) => {
let it = &self.item_tree[id];
def = Some(DefData {
id: StructLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
.intern(self.def_collector.db)
.into(),
name: &it.name,
visibility: &self.item_tree[it.visibility],
has_constructor: !matches!(it.fields, Fields::Record(_)),
});
}
ModItem::Union(id) => {
let it = &self.item_tree[id];
def = Some(DefData {
id: UnionLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
.intern(self.def_collector.db)
.into(),
name: &it.name,
visibility: &self.item_tree[it.visibility],
has_constructor: false,
});
}
ModItem::Enum(id) => {
let it = &self.item_tree[id];
def = Some(DefData {
id: EnumLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
.intern(self.def_collector.db)
.into(),
name: &it.name,
visibility: &self.item_tree[it.visibility],
has_constructor: false,
});
}
ModItem::Const(id) => {
let it = &self.item_tree[id];
let const_id = ConstLoc {
container: module.into(),
id: ItemTreeId::new(self.file_id, id),
}
.intern(self.def_collector.db);
match &it.name {
Some(name) => {
def = Some(DefData {
id: const_id.into(),
name,
visibility: &self.item_tree[it.visibility],
has_constructor: false,
});
}
None => {
// const _: T = ...;
self.def_collector.def_map.modules[self.module_id]
.scope
.define_unnamed_const(const_id);
}
}
}
ModItem::Static(id) => {
let it = &self.item_tree[id];
def = Some(DefData {
id: StaticLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
.intern(self.def_collector.db)
.into(),
name: &it.name,
visibility: &self.item_tree[it.visibility],
has_constructor: false,
});
}
ModItem::Trait(id) => {
let it = &self.item_tree[id];
def = Some(DefData {
id: TraitLoc { container: module, id: ItemTreeId::new(self.file_id, id) }
.intern(self.def_collector.db)
.into(),
name: &it.name,
visibility: &self.item_tree[it.visibility],
has_constructor: false,
});
}
ModItem::TypeAlias(id) => {
let it = &self.item_tree[id];
def = Some(DefData {
id: TypeAliasLoc {
container: module.into(),
id: ItemTreeId::new(self.file_id, id),
}
.intern(self.def_collector.db)
.into(),
name: &it.name,
visibility: &self.item_tree[it.visibility],
has_constructor: false,
});
}
}
if let Some(DefData { id, name, visibility, has_constructor }) = def {
self.def_collector.def_map.modules[self.module_id].scope.define_def(id);
let vis = self
.def_collector
.def_map
.resolve_visibility(self.def_collector.db, self.module_id, visibility)
.unwrap_or(Visibility::Public);
self.def_collector.update(
self.module_id,
&[(Some(name.clone()), PerNs::from_def(id, vis, has_constructor))],
vis,
ImportType::Named,
)
}
}
}
fn collect_module(&mut self, module: &Mod, attrs: &Attrs) {
let path_attr = attrs.by_key("path").string_value();
let is_macro_use = attrs.by_key("macro_use").exists();
match &module.kind {
// inline module, just recurse
ModKind::Inline { items } => {
let module_id = self.push_child_module(
module.name.clone(),
AstId::new(self.file_id, module.ast_id),
None,
&self.item_tree[module.visibility],
);
if let Some(mod_dir) = self.mod_dir.descend_into_definition(&module.name, path_attr)
{
ModCollector {
def_collector: &mut *self.def_collector,
macro_depth: self.macro_depth,
module_id,
file_id: self.file_id,
item_tree: self.item_tree,
mod_dir,
}
.collect(&*items);
if is_macro_use {
self.import_all_legacy_macros(module_id);
}
}
}
// out of line module, resolve, parse and recurse
ModKind::Outline {} => {
let ast_id = AstId::new(self.file_id, module.ast_id);
let db = self.def_collector.db;
match self.mod_dir.resolve_declaration(db, self.file_id, &module.name, path_attr) {
Ok((file_id, is_mod_rs, mod_dir)) => {
let item_tree = db.file_item_tree(file_id.into());
if item_tree
.top_level_attrs(db, self.def_collector.def_map.krate)
.cfg()
.map_or(true, |cfg| {
self.def_collector.cfg_options.check(&cfg) != Some(false)
})
{
let module_id = self.push_child_module(
module.name.clone(),
ast_id,
Some((file_id, is_mod_rs)),
&self.item_tree[module.visibility],
);
ModCollector {
def_collector: &mut *self.def_collector,
macro_depth: self.macro_depth,
module_id,
file_id: file_id.into(),
item_tree: &item_tree,
mod_dir,
}
.collect(item_tree.top_level_items());
if is_macro_use
|| item_tree
.top_level_attrs(db, self.def_collector.def_map.krate)
.by_key("macro_use")
.exists()
{
self.import_all_legacy_macros(module_id);
}
}
}
Err(candidate) => {
self.def_collector.def_map.diagnostics.push(
DefDiagnostic::unresolved_module(self.module_id, ast_id, candidate),
);
}
};
}
}
}
fn push_child_module(
&mut self,
name: Name,
declaration: AstId<ast::Module>,
definition: Option<(FileId, bool)>,
visibility: &crate::visibility::RawVisibility,
) -> LocalModuleId {
let vis = self
.def_collector
.def_map
.resolve_visibility(self.def_collector.db, self.module_id, visibility)
.unwrap_or(Visibility::Public);
let modules = &mut self.def_collector.def_map.modules;
let res = modules.alloc(ModuleData::default());
modules[res].parent = Some(self.module_id);
modules[res].origin = match definition {
None => ModuleOrigin::Inline { definition: declaration },
Some((definition, is_mod_rs)) => {
ModuleOrigin::File { declaration, definition, is_mod_rs }
}
};
for (name, mac) in modules[self.module_id].scope.collect_legacy_macros() {
modules[res].scope.define_legacy_macro(name, mac)
}
modules[self.module_id].children.insert(name.clone(), res);
let module = self.def_collector.def_map.module_id(res);
let def: ModuleDefId = module.into();
self.def_collector.def_map.modules[self.module_id].scope.define_def(def);
self.def_collector.update(
self.module_id,
&[(Some(name), PerNs::from_def(def, vis, false))],
vis,
ImportType::Named,
);
res
}
/// Resolves attributes on an item.
///
/// Returns `Err` when some attributes could not be resolved to builtins and have been
/// registered as unresolved.
///
/// If `ignore_up_to` is `Some`, attributes precending and including that attribute will be
/// assumed to be resolved already.
fn resolve_attributes(&mut self, attrs: &Attrs, mod_item: ModItem) -> Result<(), ()> {
let mut ignore_up_to =
self.def_collector.skip_attrs.get(&InFile::new(self.file_id, mod_item)).copied();
let iter = attrs
.iter()
.dedup_by(|a, b| {
// FIXME: this should not be required, all attributes on an item should have a
// unique ID!
// Still, this occurs because `#[cfg_attr]` can "expand" to multiple attributes:
// #[cfg_attr(not(off), unresolved, unresolved)]
// struct S;
// We should come up with a different way to ID attributes.
a.id == b.id
})
.skip_while(|attr| match ignore_up_to {
Some(id) if attr.id == id => {
ignore_up_to = None;
true
}
Some(_) => true,
None => false,
});
for attr in iter {
if attr.path.as_ident() == Some(&hir_expand::name![derive]) {
self.collect_derive(attr, mod_item);
} else if self.is_builtin_or_registered_attr(&attr.path) {
continue;
} else {
log::debug!("non-builtin attribute {}", attr.path);
let ast_id = AstIdWithPath::new(
self.file_id,
mod_item.ast_id(self.item_tree),
attr.path.as_ref().clone(),
);
self.def_collector.unresolved_macros.push(MacroDirective {
module_id: self.module_id,
depth: self.macro_depth + 1,
kind: MacroDirectiveKind::Attr { ast_id, attr: attr.clone(), mod_item },
});
return Err(());
}
}
Ok(())
}
fn is_builtin_or_registered_attr(&self, path: &ModPath) -> bool {
if path.kind == PathKind::Plain {
if let Some(tool_module) = path.segments().first() {
let tool_module = tool_module.to_string();
if builtin_attr::TOOL_MODULES
.iter()
.copied()
.chain(self.def_collector.registered_tools.iter().map(|s| &**s))
.any(|m| tool_module == *m)
{
return true;
}
}
if let Some(name) = path.as_ident() {
let name = name.to_string();
if builtin_attr::INERT_ATTRIBUTES
.iter()
.chain(builtin_attr::EXTRA_ATTRIBUTES)
.copied()
.chain(self.def_collector.registered_attrs.iter().map(|s| &**s))
.any(|attr| name == *attr)
{
return true;
}
}
}
false
}
fn collect_derive(&mut self, attr: &Attr, mod_item: ModItem) {
let ast_id: FileAstId<ast::Item> = match mod_item {
ModItem::Struct(it) => self.item_tree[it].ast_id.upcast(),
ModItem::Union(it) => self.item_tree[it].ast_id.upcast(),
ModItem::Enum(it) => self.item_tree[it].ast_id.upcast(),
_ => {
// Cannot use derive on this item.
// FIXME: diagnose
return;
}
};
match attr.parse_derive() {
Some(derive_macros) => {
for path in derive_macros {
let ast_id = AstIdWithPath::new(self.file_id, ast_id, path);
self.def_collector.unresolved_macros.push(MacroDirective {
module_id: self.module_id,
depth: self.macro_depth + 1,
kind: MacroDirectiveKind::Derive { ast_id, derive_attr: attr.id },
});
}
}
None => {
// FIXME: diagnose
log::debug!("malformed derive: {:?}", attr);
}
}
}
/// If `attrs` registers a procedural macro, collects its definition.
fn collect_proc_macro_def(&mut self, func_name: &Name, ast_id: AstId<ast::Fn>, attrs: &Attrs) {
// FIXME: this should only be done in the root module of `proc-macro` crates, not everywhere
if let Some(proc_macro) = attrs.parse_proc_macro_decl(func_name) {
self.def_collector.export_proc_macro(proc_macro, ast_id);
}
}
fn collect_macro_rules(&mut self, id: FileItemTreeId<MacroRules>) {
let krate = self.def_collector.def_map.krate;
let mac = &self.item_tree[id];
let attrs = self.item_tree.attrs(self.def_collector.db, krate, ModItem::from(id).into());
let ast_id = InFile::new(self.file_id, mac.ast_id.upcast());
let export_attr = attrs.by_key("macro_export");
let is_export = export_attr.exists();
let is_local_inner = if is_export {
export_attr.tt_values().map(|it| &it.token_trees).flatten().any(|it| match it {
tt::TokenTree::Leaf(tt::Leaf::Ident(ident)) => {
ident.text.contains("local_inner_macros")
}
_ => false,
})
} else {
false
};
// Case 1: builtin macros
if attrs.by_key("rustc_builtin_macro").exists() {
// `#[rustc_builtin_macro = "builtin_name"]` overrides the `macro_rules!` name.
let name;
let name = match attrs.by_key("rustc_builtin_macro").string_value() {
Some(it) => {
// FIXME: a hacky way to create a Name from string.
name = tt::Ident { text: it.clone(), id: tt::TokenId::unspecified() }.as_name();
&name
}
None => &mac.name,
};
let krate = self.def_collector.def_map.krate;
match find_builtin_macro(name, krate, ast_id) {
Some(macro_id) => {
self.def_collector.define_macro_rules(
self.module_id,
mac.name.clone(),
macro_id,
is_export,
);
return;
}
None => {
self.def_collector
.def_map
.diagnostics
.push(DefDiagnostic::unimplemented_builtin_macro(self.module_id, ast_id));
}
}
}
// Case 2: normal `macro_rules!` macro
let macro_id = MacroDefId {
krate: self.def_collector.def_map.krate,
kind: MacroDefKind::Declarative(ast_id),
local_inner: is_local_inner,
};
self.def_collector.define_macro_rules(
self.module_id,
mac.name.clone(),
macro_id,
is_export,
);
}
fn collect_macro_def(&mut self, id: FileItemTreeId<MacroDef>) {
let krate = self.def_collector.def_map.krate;
let mac = &self.item_tree[id];
let ast_id = InFile::new(self.file_id, mac.ast_id.upcast());
// Case 1: bulitin macros
let attrs = self.item_tree.attrs(self.def_collector.db, krate, ModItem::from(id).into());
if attrs.by_key("rustc_builtin_macro").exists() {
let macro_id = find_builtin_macro(&mac.name, krate, ast_id)
.or_else(|| find_builtin_derive(&mac.name, krate, ast_id))
.or_else(|| find_builtin_attr(&mac.name, krate, ast_id));
match macro_id {
Some(macro_id) => {
self.def_collector.define_macro_def(
self.module_id,
mac.name.clone(),
macro_id,
&self.item_tree[mac.visibility],
);
return;
}
None => {
self.def_collector
.def_map
.diagnostics
.push(DefDiagnostic::unimplemented_builtin_macro(self.module_id, ast_id));
}
}
}
// Case 2: normal `macro`
let macro_id = MacroDefId {
krate: self.def_collector.def_map.krate,
kind: MacroDefKind::Declarative(ast_id),
local_inner: false,
};
self.def_collector.define_macro_def(
self.module_id,
mac.name.clone(),
macro_id,
&self.item_tree[mac.visibility],
);
}
fn collect_macro_call(&mut self, mac: &MacroCall) {
let mut ast_id = AstIdWithPath::new(self.file_id, mac.ast_id, (*mac.path).clone());
// Case 1: try to resolve in legacy scope and expand macro_rules
let mut error = None;
match macro_call_as_call_id(
&ast_id,
mac.fragment,
self.def_collector.db,
self.def_collector.def_map.krate,
|path| {
path.as_ident().and_then(|name| {
self.def_collector.def_map.with_ancestor_maps(
self.def_collector.db,
self.module_id,
&mut |map, module| map[module].scope.get_legacy_macro(name),
)
})
},
&mut |err| {
error.get_or_insert(err);
},
) {
Ok(Ok(macro_call_id)) => {
// Legacy macros need to be expanded immediately, so that any macros they produce
// are in scope.
self.def_collector.collect_macro_expansion(
self.module_id,
macro_call_id,
self.macro_depth + 1,
);
return;
}
Ok(Err(_)) => {
// Built-in macro failed eager expansion.
// FIXME: don't parse the file here
let fragment = hir_expand::to_fragment_kind(
&ast_id.ast_id.to_node(self.def_collector.db.upcast()),
);
self.def_collector.def_map.diagnostics.push(DefDiagnostic::macro_error(
self.module_id,
MacroCallKind::FnLike { ast_id: ast_id.ast_id, fragment },
error.unwrap().to_string(),
));
return;
}
Err(UnresolvedMacro { .. }) => (),
}
// Case 2: resolve in module scope, expand during name resolution.
// We rewrite simple path `macro_name` to `self::macro_name` to force resolve in module scope only.
if ast_id.path.is_ident() {
ast_id.path.kind = PathKind::Super(0);
}
self.def_collector.unresolved_macros.push(MacroDirective {
module_id: self.module_id,
depth: self.macro_depth + 1,
kind: MacroDirectiveKind::FnLike { ast_id, fragment: mac.fragment },
});
}
fn import_all_legacy_macros(&mut self, module_id: LocalModuleId) {
let macros = self.def_collector.def_map[module_id].scope.collect_legacy_macros();
for (name, macro_) in macros {
self.def_collector.define_legacy_macro(self.module_id, name.clone(), macro_);
}
}
fn is_cfg_enabled(&self, cfg: &CfgExpr) -> bool {
self.def_collector.cfg_options.check(cfg) != Some(false)
}
fn emit_unconfigured_diagnostic(&mut self, item: ModItem, cfg: &CfgExpr) {
let ast_id = item.ast_id(self.item_tree);
let ast_id = InFile::new(self.file_id, ast_id);
self.def_collector.def_map.diagnostics.push(DefDiagnostic::unconfigured_code(
self.module_id,
ast_id,
cfg.clone(),
self.def_collector.cfg_options.clone(),
));
}
}
#[cfg(test)]
mod tests {
use crate::{db::DefDatabase, test_db::TestDB};
use base_db::{fixture::WithFixture, SourceDatabase};
use super::*;
fn do_collect_defs(db: &dyn DefDatabase, def_map: DefMap) -> DefMap {
let mut collector = DefCollector {
db,
def_map,
glob_imports: FxHashMap::default(),
unresolved_imports: Vec::new(),
resolved_imports: Vec::new(),
unresolved_macros: Vec::new(),
mod_dirs: FxHashMap::default(),
cfg_options: &CfgOptions::default(),
proc_macros: Default::default(),
exports_proc_macros: false,
from_glob_import: Default::default(),
skip_attrs: Default::default(),
derive_helpers_in_scope: Default::default(),
registered_attrs: Default::default(),
registered_tools: Default::default(),
};
collector.seed_with_top_level();
collector.collect();
collector.def_map
}
fn do_resolve(not_ra_fixture: &str) -> DefMap {
let (db, _file_id) = TestDB::with_single_file(not_ra_fixture);
let krate = db.test_crate();
let edition = db.crate_graph()[krate].edition;
let def_map = DefMap::empty(krate, edition);
do_collect_defs(&db, def_map)
}
#[test]
fn test_macro_expand_will_stop_1() {
do_resolve(
r#"
macro_rules! foo {
($($ty:ty)*) => { foo!($($ty)*); }
}
foo!(KABOOM);
"#,
);
do_resolve(
r#"
macro_rules! foo {
($($ty:ty)*) => { foo!(() $($ty)*); }
}
foo!(KABOOM);
"#,
);
}
#[ignore]
#[test]
fn test_macro_expand_will_stop_2() {
// FIXME: this test does succeed, but takes quite a while: 90 seconds in
// the release mode. That's why the argument is not an ra_fixture --
// otherwise injection highlighting gets stuck.
//
// We need to find a way to fail this faster.
do_resolve(
r#"
macro_rules! foo {
($($ty:ty)*) => { foo!($($ty)* $($ty)*); }
}
foo!(KABOOM);
"#,
);
}
}