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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /src/librustdoc/clean/utils.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/librustdoc/clean/utils.rs')
-rw-r--r--src/librustdoc/clean/utils.rs616
1 files changed, 616 insertions, 0 deletions
diff --git a/src/librustdoc/clean/utils.rs b/src/librustdoc/clean/utils.rs
new file mode 100644
index 000000000..43e71e90a
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+++ b/src/librustdoc/clean/utils.rs
@@ -0,0 +1,616 @@
+use crate::clean::auto_trait::AutoTraitFinder;
+use crate::clean::blanket_impl::BlanketImplFinder;
+use crate::clean::render_macro_matchers::render_macro_matcher;
+use crate::clean::{
+ clean_middle_const, clean_middle_region, clean_middle_ty, inline, Clean, Crate, ExternalCrate,
+ Generic, GenericArg, GenericArgs, ImportSource, Item, ItemKind, Lifetime, Path, PathSegment,
+ Primitive, PrimitiveType, Type, TypeBinding, Visibility,
+};
+use crate::core::DocContext;
+use crate::formats::item_type::ItemType;
+use crate::visit_lib::LibEmbargoVisitor;
+
+use rustc_ast as ast;
+use rustc_ast::tokenstream::TokenTree;
+use rustc_data_structures::thin_vec::ThinVec;
+use rustc_hir as hir;
+use rustc_hir::def::{DefKind, Res};
+use rustc_hir::def_id::{DefId, LOCAL_CRATE};
+use rustc_middle::mir;
+use rustc_middle::mir::interpret::ConstValue;
+use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
+use rustc_middle::ty::{self, DefIdTree, TyCtxt};
+use rustc_span::symbol::{kw, sym, Symbol};
+use std::fmt::Write as _;
+use std::mem;
+
+#[cfg(test)]
+mod tests;
+
+pub(crate) fn krate(cx: &mut DocContext<'_>) -> Crate {
+ let module = crate::visit_ast::RustdocVisitor::new(cx).visit();
+
+ for &cnum in cx.tcx.crates(()) {
+ // Analyze doc-reachability for extern items
+ LibEmbargoVisitor::new(cx).visit_lib(cnum);
+ }
+
+ // Clean the crate, translating the entire librustc_ast AST to one that is
+ // understood by rustdoc.
+ let mut module = module.clean(cx);
+
+ match *module.kind {
+ ItemKind::ModuleItem(ref module) => {
+ for it in &module.items {
+ // `compiler_builtins` should be masked too, but we can't apply
+ // `#[doc(masked)]` to the injected `extern crate` because it's unstable.
+ if it.is_extern_crate()
+ && (it.attrs.has_doc_flag(sym::masked)
+ || cx.tcx.is_compiler_builtins(it.item_id.krate()))
+ {
+ cx.cache.masked_crates.insert(it.item_id.krate());
+ }
+ }
+ }
+ _ => unreachable!(),
+ }
+
+ let local_crate = ExternalCrate { crate_num: LOCAL_CRATE };
+ let primitives = local_crate.primitives(cx.tcx);
+ let keywords = local_crate.keywords(cx.tcx);
+ {
+ let ItemKind::ModuleItem(ref mut m) = *module.kind
+ else { unreachable!() };
+ m.items.extend(primitives.iter().map(|&(def_id, prim)| {
+ Item::from_def_id_and_parts(
+ def_id,
+ Some(prim.as_sym()),
+ ItemKind::PrimitiveItem(prim),
+ cx,
+ )
+ }));
+ m.items.extend(keywords.into_iter().map(|(def_id, kw)| {
+ Item::from_def_id_and_parts(def_id, Some(kw), ItemKind::KeywordItem, cx)
+ }));
+ }
+
+ Crate { module, primitives, external_traits: cx.external_traits.clone() }
+}
+
+pub(crate) fn substs_to_args<'tcx>(
+ cx: &mut DocContext<'tcx>,
+ substs: &[ty::subst::GenericArg<'tcx>],
+ mut skip_first: bool,
+) -> Vec<GenericArg> {
+ let mut ret_val =
+ Vec::with_capacity(substs.len().saturating_sub(if skip_first { 1 } else { 0 }));
+ ret_val.extend(substs.iter().filter_map(|kind| match kind.unpack() {
+ GenericArgKind::Lifetime(lt) => {
+ Some(GenericArg::Lifetime(clean_middle_region(lt).unwrap_or(Lifetime::elided())))
+ }
+ GenericArgKind::Type(_) if skip_first => {
+ skip_first = false;
+ None
+ }
+ GenericArgKind::Type(ty) => Some(GenericArg::Type(clean_middle_ty(ty, cx, None))),
+ GenericArgKind::Const(ct) => Some(GenericArg::Const(Box::new(clean_middle_const(ct, cx)))),
+ }));
+ ret_val
+}
+
+fn external_generic_args<'tcx>(
+ cx: &mut DocContext<'tcx>,
+ did: DefId,
+ has_self: bool,
+ bindings: Vec<TypeBinding>,
+ substs: SubstsRef<'tcx>,
+) -> GenericArgs {
+ let args = substs_to_args(cx, substs, has_self);
+
+ if cx.tcx.fn_trait_kind_from_lang_item(did).is_some() {
+ let inputs =
+ // The trait's first substitution is the one after self, if there is one.
+ match substs.iter().nth(if has_self { 1 } else { 0 }).unwrap().expect_ty().kind() {
+ ty::Tuple(tys) => tys.iter().map(|t| clean_middle_ty(t, cx, None)).collect::<Vec<_>>().into(),
+ _ => return GenericArgs::AngleBracketed { args: args.into(), bindings: bindings.into() },
+ };
+ let output = None;
+ // FIXME(#20299) return type comes from a projection now
+ // match types[1].kind {
+ // ty::Tuple(ref v) if v.is_empty() => None, // -> ()
+ // _ => Some(types[1].clean(cx))
+ // };
+ GenericArgs::Parenthesized { inputs, output }
+ } else {
+ GenericArgs::AngleBracketed { args: args.into(), bindings: bindings.into() }
+ }
+}
+
+pub(super) fn external_path<'tcx>(
+ cx: &mut DocContext<'tcx>,
+ did: DefId,
+ has_self: bool,
+ bindings: Vec<TypeBinding>,
+ substs: SubstsRef<'tcx>,
+) -> Path {
+ let def_kind = cx.tcx.def_kind(did);
+ let name = cx.tcx.item_name(did);
+ Path {
+ res: Res::Def(def_kind, did),
+ segments: vec![PathSegment {
+ name,
+ args: external_generic_args(cx, did, has_self, bindings, substs),
+ }],
+ }
+}
+
+/// Remove the generic arguments from a path.
+pub(crate) fn strip_path_generics(mut path: Path) -> Path {
+ for ps in path.segments.iter_mut() {
+ ps.args = GenericArgs::AngleBracketed { args: Default::default(), bindings: ThinVec::new() }
+ }
+
+ path
+}
+
+pub(crate) fn qpath_to_string(p: &hir::QPath<'_>) -> String {
+ let segments = match *p {
+ hir::QPath::Resolved(_, path) => &path.segments,
+ hir::QPath::TypeRelative(_, segment) => return segment.ident.to_string(),
+ hir::QPath::LangItem(lang_item, ..) => return lang_item.name().to_string(),
+ };
+
+ let mut s = String::new();
+ for (i, seg) in segments.iter().enumerate() {
+ if i > 0 {
+ s.push_str("::");
+ }
+ if seg.ident.name != kw::PathRoot {
+ s.push_str(seg.ident.as_str());
+ }
+ }
+ s
+}
+
+pub(crate) fn build_deref_target_impls(
+ cx: &mut DocContext<'_>,
+ items: &[Item],
+ ret: &mut Vec<Item>,
+) {
+ let tcx = cx.tcx;
+
+ for item in items {
+ let target = match *item.kind {
+ ItemKind::AssocTypeItem(ref t, _) => &t.type_,
+ _ => continue,
+ };
+
+ if let Some(prim) = target.primitive_type() {
+ let _prof_timer = cx.tcx.sess.prof.generic_activity("build_primitive_inherent_impls");
+ for did in prim.impls(tcx).filter(|did| !did.is_local()) {
+ inline::build_impl(cx, None, did, None, ret);
+ }
+ } else if let Type::Path { path } = target {
+ let did = path.def_id();
+ if !did.is_local() {
+ inline::build_impls(cx, None, did, None, ret);
+ }
+ }
+ }
+}
+
+pub(crate) fn name_from_pat(p: &hir::Pat<'_>) -> Symbol {
+ use rustc_hir::*;
+ debug!("trying to get a name from pattern: {:?}", p);
+
+ Symbol::intern(&match p.kind {
+ PatKind::Wild | PatKind::Struct(..) => return kw::Underscore,
+ PatKind::Binding(_, _, ident, _) => return ident.name,
+ PatKind::TupleStruct(ref p, ..) | PatKind::Path(ref p) => qpath_to_string(p),
+ PatKind::Or(pats) => {
+ pats.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(" | ")
+ }
+ PatKind::Tuple(elts, _) => format!(
+ "({})",
+ elts.iter().map(|p| name_from_pat(p).to_string()).collect::<Vec<String>>().join(", ")
+ ),
+ PatKind::Box(p) => return name_from_pat(&*p),
+ PatKind::Ref(p, _) => return name_from_pat(&*p),
+ PatKind::Lit(..) => {
+ warn!(
+ "tried to get argument name from PatKind::Lit, which is silly in function arguments"
+ );
+ return Symbol::intern("()");
+ }
+ PatKind::Range(..) => return kw::Underscore,
+ PatKind::Slice(begin, ref mid, end) => {
+ let begin = begin.iter().map(|p| name_from_pat(p).to_string());
+ let mid = mid.as_ref().map(|p| format!("..{}", name_from_pat(&**p))).into_iter();
+ let end = end.iter().map(|p| name_from_pat(p).to_string());
+ format!("[{}]", begin.chain(mid).chain(end).collect::<Vec<_>>().join(", "))
+ }
+ })
+}
+
+pub(crate) fn print_const(cx: &DocContext<'_>, n: ty::Const<'_>) -> String {
+ match n.kind() {
+ ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted }) => {
+ let mut s = if let Some(def) = def.as_local() {
+ print_const_expr(cx.tcx, cx.tcx.hir().body_owned_by(def.did))
+ } else {
+ inline::print_inlined_const(cx.tcx, def.did)
+ };
+ if let Some(promoted) = promoted {
+ s.push_str(&format!("::{:?}", promoted))
+ }
+ s
+ }
+ _ => {
+ let mut s = n.to_string();
+ // array lengths are obviously usize
+ if s.ends_with("_usize") {
+ let n = s.len() - "_usize".len();
+ s.truncate(n);
+ if s.ends_with(": ") {
+ let n = s.len() - ": ".len();
+ s.truncate(n);
+ }
+ }
+ s
+ }
+ }
+}
+
+pub(crate) fn print_evaluated_const(tcx: TyCtxt<'_>, def_id: DefId) -> Option<String> {
+ tcx.const_eval_poly(def_id).ok().and_then(|val| {
+ let ty = tcx.type_of(def_id);
+ match (val, ty.kind()) {
+ (_, &ty::Ref(..)) => None,
+ (ConstValue::Scalar(_), &ty::Adt(_, _)) => None,
+ (ConstValue::Scalar(_), _) => {
+ let const_ = mir::ConstantKind::from_value(val, ty);
+ Some(print_const_with_custom_print_scalar(tcx, const_))
+ }
+ _ => None,
+ }
+ })
+}
+
+fn format_integer_with_underscore_sep(num: &str) -> String {
+ let num_chars: Vec<_> = num.chars().collect();
+ let mut num_start_index = if num_chars.get(0) == Some(&'-') { 1 } else { 0 };
+ let chunk_size = match num[num_start_index..].as_bytes() {
+ [b'0', b'b' | b'x', ..] => {
+ num_start_index += 2;
+ 4
+ }
+ [b'0', b'o', ..] => {
+ num_start_index += 2;
+ let remaining_chars = num_chars.len() - num_start_index;
+ if remaining_chars <= 6 {
+ // don't add underscores to Unix permissions like 0755 or 100755
+ return num.to_string();
+ }
+ 3
+ }
+ _ => 3,
+ };
+
+ num_chars[..num_start_index]
+ .iter()
+ .chain(num_chars[num_start_index..].rchunks(chunk_size).rev().intersperse(&['_']).flatten())
+ .collect()
+}
+
+fn print_const_with_custom_print_scalar(tcx: TyCtxt<'_>, ct: mir::ConstantKind<'_>) -> String {
+ // Use a slightly different format for integer types which always shows the actual value.
+ // For all other types, fallback to the original `pretty_print_const`.
+ match (ct, ct.ty().kind()) {
+ (mir::ConstantKind::Val(ConstValue::Scalar(int), _), ty::Uint(ui)) => {
+ format!("{}{}", format_integer_with_underscore_sep(&int.to_string()), ui.name_str())
+ }
+ (mir::ConstantKind::Val(ConstValue::Scalar(int), _), ty::Int(i)) => {
+ let ty = tcx.lift(ct.ty()).unwrap();
+ let size = tcx.layout_of(ty::ParamEnv::empty().and(ty)).unwrap().size;
+ let data = int.assert_bits(size);
+ let sign_extended_data = size.sign_extend(data) as i128;
+ format!(
+ "{}{}",
+ format_integer_with_underscore_sep(&sign_extended_data.to_string()),
+ i.name_str()
+ )
+ }
+ _ => ct.to_string(),
+ }
+}
+
+pub(crate) fn is_literal_expr(tcx: TyCtxt<'_>, hir_id: hir::HirId) -> bool {
+ if let hir::Node::Expr(expr) = tcx.hir().get(hir_id) {
+ if let hir::ExprKind::Lit(_) = &expr.kind {
+ return true;
+ }
+
+ if let hir::ExprKind::Unary(hir::UnOp::Neg, expr) = &expr.kind {
+ if let hir::ExprKind::Lit(_) = &expr.kind {
+ return true;
+ }
+ }
+ }
+
+ false
+}
+
+/// Build a textual representation of an unevaluated constant expression.
+///
+/// If the const expression is too complex, an underscore `_` is returned.
+/// For const arguments, it's `{ _ }` to be precise.
+/// This means that the output is not necessarily valid Rust code.
+///
+/// Currently, only
+///
+/// * literals (optionally with a leading `-`)
+/// * unit `()`
+/// * blocks (`{ … }`) around simple expressions and
+/// * paths without arguments
+///
+/// are considered simple enough. Simple blocks are included since they are
+/// necessary to disambiguate unit from the unit type.
+/// This list might get extended in the future.
+///
+/// Without this censoring, in a lot of cases the output would get too large
+/// and verbose. Consider `match` expressions, blocks and deeply nested ADTs.
+/// Further, private and `doc(hidden)` fields of structs would get leaked
+/// since HIR datatypes like the `body` parameter do not contain enough
+/// semantic information for this function to be able to hide them –
+/// at least not without significant performance overhead.
+///
+/// Whenever possible, prefer to evaluate the constant first and try to
+/// use a different method for pretty-printing. Ideally this function
+/// should only ever be used as a fallback.
+pub(crate) fn print_const_expr(tcx: TyCtxt<'_>, body: hir::BodyId) -> String {
+ let hir = tcx.hir();
+ let value = &hir.body(body).value;
+
+ #[derive(PartialEq, Eq)]
+ enum Classification {
+ Literal,
+ Simple,
+ Complex,
+ }
+
+ use Classification::*;
+
+ fn classify(expr: &hir::Expr<'_>) -> Classification {
+ match &expr.kind {
+ hir::ExprKind::Unary(hir::UnOp::Neg, expr) => {
+ if matches!(expr.kind, hir::ExprKind::Lit(_)) { Literal } else { Complex }
+ }
+ hir::ExprKind::Lit(_) => Literal,
+ hir::ExprKind::Tup([]) => Simple,
+ hir::ExprKind::Block(hir::Block { stmts: [], expr: Some(expr), .. }, _) => {
+ if classify(expr) == Complex { Complex } else { Simple }
+ }
+ // Paths with a self-type or arguments are too “complex” following our measure since
+ // they may leak private fields of structs (with feature `adt_const_params`).
+ // Consider: `<Self as Trait<{ Struct { private: () } }>>::CONSTANT`.
+ // Paths without arguments are definitely harmless though.
+ hir::ExprKind::Path(hir::QPath::Resolved(_, hir::Path { segments, .. })) => {
+ if segments.iter().all(|segment| segment.args.is_none()) { Simple } else { Complex }
+ }
+ // FIXME: Claiming that those kinds of QPaths are simple is probably not true if the Ty
+ // contains const arguments. Is there a *concise* way to check for this?
+ hir::ExprKind::Path(hir::QPath::TypeRelative(..)) => Simple,
+ // FIXME: Can they contain const arguments and thus leak private struct fields?
+ hir::ExprKind::Path(hir::QPath::LangItem(..)) => Simple,
+ _ => Complex,
+ }
+ }
+
+ let classification = classify(value);
+
+ if classification == Literal
+ && !value.span.from_expansion()
+ && let Ok(snippet) = tcx.sess.source_map().span_to_snippet(value.span) {
+ // For literals, we avoid invoking the pretty-printer and use the source snippet instead to
+ // preserve certain stylistic choices the user likely made for the sake legibility like
+ //
+ // * hexadecimal notation
+ // * underscores
+ // * character escapes
+ //
+ // FIXME: This passes through `-/*spacer*/0` verbatim.
+ snippet
+ } else if classification == Simple {
+ // Otherwise we prefer pretty-printing to get rid of extraneous whitespace, comments and
+ // other formatting artifacts.
+ rustc_hir_pretty::id_to_string(&hir, body.hir_id)
+ } else if tcx.def_kind(hir.body_owner_def_id(body).to_def_id()) == DefKind::AnonConst {
+ // FIXME: Omit the curly braces if the enclosing expression is an array literal
+ // with a repeated element (an `ExprKind::Repeat`) as in such case it
+ // would not actually need any disambiguation.
+ "{ _ }".to_owned()
+ } else {
+ "_".to_owned()
+ }
+}
+
+/// Given a type Path, resolve it to a Type using the TyCtxt
+pub(crate) fn resolve_type(cx: &mut DocContext<'_>, path: Path) -> Type {
+ debug!("resolve_type({:?})", path);
+
+ match path.res {
+ Res::PrimTy(p) => Primitive(PrimitiveType::from(p)),
+ Res::SelfTy { .. } if path.segments.len() == 1 => Generic(kw::SelfUpper),
+ Res::Def(DefKind::TyParam, _) if path.segments.len() == 1 => Generic(path.segments[0].name),
+ _ => {
+ let _ = register_res(cx, path.res);
+ Type::Path { path }
+ }
+ }
+}
+
+pub(crate) fn get_auto_trait_and_blanket_impls(
+ cx: &mut DocContext<'_>,
+ item_def_id: DefId,
+) -> impl Iterator<Item = Item> {
+ let auto_impls = cx
+ .sess()
+ .prof
+ .generic_activity("get_auto_trait_impls")
+ .run(|| AutoTraitFinder::new(cx).get_auto_trait_impls(item_def_id));
+ let blanket_impls = cx
+ .sess()
+ .prof
+ .generic_activity("get_blanket_impls")
+ .run(|| BlanketImplFinder { cx }.get_blanket_impls(item_def_id));
+ auto_impls.into_iter().chain(blanket_impls)
+}
+
+/// If `res` has a documentation page associated, store it in the cache.
+///
+/// This is later used by [`href()`] to determine the HTML link for the item.
+///
+/// [`href()`]: crate::html::format::href
+pub(crate) fn register_res(cx: &mut DocContext<'_>, res: Res) -> DefId {
+ use DefKind::*;
+ debug!("register_res({:?})", res);
+
+ let (did, kind) = match res {
+ // These should be added to the cache using `record_extern_fqn`.
+ Res::Def(
+ kind @ (AssocTy | AssocFn | AssocConst | Variant | Fn | TyAlias | Enum | Trait | Struct
+ | Union | Mod | ForeignTy | Const | Static(_) | Macro(..) | TraitAlias),
+ i,
+ ) => (i, kind.into()),
+ // This is part of a trait definition or trait impl; document the trait.
+ Res::SelfTy { trait_: Some(trait_def_id), alias_to: _ } => (trait_def_id, ItemType::Trait),
+ // This is an inherent impl or a type definition; it doesn't have its own page.
+ Res::SelfTy { trait_: None, alias_to: Some((item_def_id, _)) } => return item_def_id,
+ Res::SelfTy { trait_: None, alias_to: None }
+ | Res::PrimTy(_)
+ | Res::ToolMod
+ | Res::SelfCtor(_)
+ | Res::Local(_)
+ | Res::NonMacroAttr(_)
+ | Res::Err => return res.def_id(),
+ Res::Def(
+ TyParam | ConstParam | Ctor(..) | ExternCrate | Use | ForeignMod | AnonConst
+ | InlineConst | OpaqueTy | Field | LifetimeParam | GlobalAsm | Impl | Closure
+ | Generator,
+ id,
+ ) => return id,
+ };
+ if did.is_local() {
+ return did;
+ }
+ inline::record_extern_fqn(cx, did, kind);
+ if let ItemType::Trait = kind {
+ inline::record_extern_trait(cx, did);
+ }
+ did
+}
+
+pub(crate) fn resolve_use_source(cx: &mut DocContext<'_>, path: Path) -> ImportSource {
+ ImportSource {
+ did: if path.res.opt_def_id().is_none() { None } else { Some(register_res(cx, path.res)) },
+ path,
+ }
+}
+
+pub(crate) fn enter_impl_trait<'tcx, F, R>(cx: &mut DocContext<'tcx>, f: F) -> R
+where
+ F: FnOnce(&mut DocContext<'tcx>) -> R,
+{
+ let old_bounds = mem::take(&mut cx.impl_trait_bounds);
+ let r = f(cx);
+ assert!(cx.impl_trait_bounds.is_empty());
+ cx.impl_trait_bounds = old_bounds;
+ r
+}
+
+/// Find the nearest parent module of a [`DefId`].
+pub(crate) fn find_nearest_parent_module(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
+ if def_id.is_top_level_module() {
+ // The crate root has no parent. Use it as the root instead.
+ Some(def_id)
+ } else {
+ let mut current = def_id;
+ // The immediate parent might not always be a module.
+ // Find the first parent which is.
+ while let Some(parent) = tcx.opt_parent(current) {
+ if tcx.def_kind(parent) == DefKind::Mod {
+ return Some(parent);
+ }
+ current = parent;
+ }
+ None
+ }
+}
+
+/// Checks for the existence of `hidden` in the attribute below if `flag` is `sym::hidden`:
+///
+/// ```
+/// #[doc(hidden)]
+/// pub fn foo() {}
+/// ```
+///
+/// This function exists because it runs on `hir::Attributes` whereas the other is a
+/// `clean::Attributes` method.
+pub(crate) fn has_doc_flag(tcx: TyCtxt<'_>, did: DefId, flag: Symbol) -> bool {
+ tcx.get_attrs(did, sym::doc).any(|attr| {
+ attr.meta_item_list().map_or(false, |l| rustc_attr::list_contains_name(&l, flag))
+ })
+}
+
+/// A link to `doc.rust-lang.org` that includes the channel name. Use this instead of manual links
+/// so that the channel is consistent.
+///
+/// Set by `bootstrap::Builder::doc_rust_lang_org_channel` in order to keep tests passing on beta/stable.
+pub(crate) const DOC_RUST_LANG_ORG_CHANNEL: &str = env!("DOC_RUST_LANG_ORG_CHANNEL");
+
+/// Render a sequence of macro arms in a format suitable for displaying to the user
+/// as part of an item declaration.
+pub(super) fn render_macro_arms<'a>(
+ tcx: TyCtxt<'_>,
+ matchers: impl Iterator<Item = &'a TokenTree>,
+ arm_delim: &str,
+) -> String {
+ let mut out = String::new();
+ for matcher in matchers {
+ writeln!(out, " {} => {{ ... }}{}", render_macro_matcher(tcx, matcher), arm_delim)
+ .unwrap();
+ }
+ out
+}
+
+pub(super) fn display_macro_source(
+ cx: &mut DocContext<'_>,
+ name: Symbol,
+ def: &ast::MacroDef,
+ def_id: DefId,
+ vis: Visibility,
+) -> String {
+ let tts: Vec<_> = def.body.inner_tokens().into_trees().collect();
+ // Extract the spans of all matchers. They represent the "interface" of the macro.
+ let matchers = tts.chunks(4).map(|arm| &arm[0]);
+
+ if def.macro_rules {
+ format!("macro_rules! {} {{\n{}}}", name, render_macro_arms(cx.tcx, matchers, ";"))
+ } else {
+ if matchers.len() <= 1 {
+ format!(
+ "{}macro {}{} {{\n ...\n}}",
+ vis.to_src_with_space(cx.tcx, def_id),
+ name,
+ matchers.map(|matcher| render_macro_matcher(cx.tcx, matcher)).collect::<String>(),
+ )
+ } else {
+ format!(
+ "{}macro {} {{\n{}}}",
+ vis.to_src_with_space(cx.tcx, def_id),
+ name,
+ render_macro_arms(cx.tcx, matchers, ","),
+ )
+ }
+ }
+}