From b28c54a2c239acd73f2eea80fda9ee3960d2c046 Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Thu, 13 Aug 2020 16:28:27 +0200 Subject: Rename ra_hir_def -> hir_def --- crates/hir_def/src/path/lower.rs | 215 +++++++++++++++++++++++++++++ crates/hir_def/src/path/lower/lower_use.rs | 120 ++++++++++++++++ 2 files changed, 335 insertions(+) create mode 100644 crates/hir_def/src/path/lower.rs create mode 100644 crates/hir_def/src/path/lower/lower_use.rs (limited to 'crates/hir_def/src/path') diff --git a/crates/hir_def/src/path/lower.rs b/crates/hir_def/src/path/lower.rs new file mode 100644 index 000000000..07b9723ce --- /dev/null +++ b/crates/hir_def/src/path/lower.rs @@ -0,0 +1,215 @@ +//! Transforms syntax into `Path` objects, ideally with accounting for hygiene + +mod lower_use; + +use std::sync::Arc; + +use either::Either; +use hir_expand::{ + hygiene::Hygiene, + name::{name, AsName}, +}; +use syntax::ast::{self, AstNode, TypeBoundsOwner}; + +use super::AssociatedTypeBinding; +use crate::{ + body::LowerCtx, + path::{GenericArg, GenericArgs, ModPath, Path, PathKind}, + type_ref::{TypeBound, TypeRef}, +}; + +pub(super) use lower_use::lower_use_tree; + +/// Converts an `ast::Path` to `Path`. Works with use trees. +/// It correctly handles `$crate` based path from macro call. +pub(super) fn lower_path(mut path: ast::Path, hygiene: &Hygiene) -> Option { + let mut kind = PathKind::Plain; + let mut type_anchor = None; + let mut segments = Vec::new(); + let mut generic_args = Vec::new(); + let ctx = LowerCtx::with_hygiene(hygiene); + loop { + let segment = path.segment()?; + + if segment.coloncolon_token().is_some() { + kind = PathKind::Abs; + } + + match segment.kind()? { + ast::PathSegmentKind::Name(name_ref) => { + // FIXME: this should just return name + match hygiene.name_ref_to_name(name_ref) { + Either::Left(name) => { + let args = segment + .generic_arg_list() + .and_then(|it| lower_generic_args(&ctx, it)) + .or_else(|| { + lower_generic_args_from_fn_path( + &ctx, + segment.param_list(), + segment.ret_type(), + ) + }) + .map(Arc::new); + segments.push(name); + generic_args.push(args) + } + Either::Right(crate_id) => { + kind = PathKind::DollarCrate(crate_id); + break; + } + } + } + ast::PathSegmentKind::Type { type_ref, trait_ref } => { + assert!(path.qualifier().is_none()); // this can only occur at the first segment + + let self_type = TypeRef::from_ast(&ctx, type_ref?); + + match trait_ref { + // ::foo + None => { + type_anchor = Some(Box::new(self_type)); + kind = PathKind::Plain; + } + // >::Foo desugars to Trait::Foo + Some(trait_ref) => { + let path = Path::from_src(trait_ref.path()?, hygiene)?; + kind = path.mod_path.kind; + + let mut prefix_segments = path.mod_path.segments; + prefix_segments.reverse(); + segments.extend(prefix_segments); + + let mut prefix_args = path.generic_args; + prefix_args.reverse(); + generic_args.extend(prefix_args); + + // Insert the type reference (T in the above example) as Self parameter for the trait + let last_segment = generic_args.last_mut()?; + if last_segment.is_none() { + *last_segment = Some(Arc::new(GenericArgs::empty())); + }; + let args = last_segment.as_mut().unwrap(); + let mut args_inner = Arc::make_mut(args); + args_inner.has_self_type = true; + args_inner.args.insert(0, GenericArg::Type(self_type)); + } + } + } + ast::PathSegmentKind::CrateKw => { + kind = PathKind::Crate; + break; + } + ast::PathSegmentKind::SelfKw => { + kind = PathKind::Super(0); + break; + } + ast::PathSegmentKind::SuperKw => { + let nested_super_count = if let PathKind::Super(n) = kind { n } else { 0 }; + kind = PathKind::Super(nested_super_count + 1); + } + } + path = match qualifier(&path) { + Some(it) => it, + None => break, + }; + } + segments.reverse(); + generic_args.reverse(); + + // handle local_inner_macros : + // Basically, even in rustc it is quite hacky: + // https://github.com/rust-lang/rust/blob/614f273e9388ddd7804d5cbc80b8865068a3744e/src/librustc_resolve/macros.rs#L456 + // We follow what it did anyway :) + if segments.len() == 1 && kind == PathKind::Plain { + if let Some(macro_call) = path.syntax().parent().and_then(ast::MacroCall::cast) { + if macro_call.is_bang() { + if let Some(crate_id) = hygiene.local_inner_macros() { + kind = PathKind::DollarCrate(crate_id); + } + } + } + } + + let mod_path = ModPath { kind, segments }; + return Some(Path { type_anchor, mod_path, generic_args }); + + fn qualifier(path: &ast::Path) -> Option { + if let Some(q) = path.qualifier() { + return Some(q); + } + // FIXME: this bottom up traversal is not too precise. + // Should we handle do a top-down analysis, recording results? + let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?; + let use_tree = use_tree_list.parent_use_tree(); + use_tree.path() + } +} + +pub(super) fn lower_generic_args( + lower_ctx: &LowerCtx, + node: ast::GenericArgList, +) -> Option { + let mut args = Vec::new(); + let mut bindings = Vec::new(); + for generic_arg in node.generic_args() { + match generic_arg { + ast::GenericArg::TypeArg(type_arg) => { + let type_ref = TypeRef::from_ast_opt(lower_ctx, type_arg.ty()); + args.push(GenericArg::Type(type_ref)); + } + ast::GenericArg::AssocTypeArg(assoc_type_arg) => { + if let Some(name_ref) = assoc_type_arg.name_ref() { + let name = name_ref.as_name(); + let type_ref = assoc_type_arg.ty().map(|it| TypeRef::from_ast(lower_ctx, it)); + let bounds = if let Some(l) = assoc_type_arg.type_bound_list() { + l.bounds().map(|it| TypeBound::from_ast(lower_ctx, it)).collect() + } else { + Vec::new() + }; + bindings.push(AssociatedTypeBinding { name, type_ref, bounds }); + } + } + // Lifetimes and constants are ignored for now. + ast::GenericArg::LifetimeArg(_) | ast::GenericArg::ConstArg(_) => (), + } + } + + if args.is_empty() && bindings.is_empty() { + return None; + } + Some(GenericArgs { args, has_self_type: false, bindings }) +} + +/// Collect `GenericArgs` from the parts of a fn-like path, i.e. `Fn(X, Y) +/// -> Z` (which desugars to `Fn<(X, Y), Output=Z>`). +fn lower_generic_args_from_fn_path( + ctx: &LowerCtx, + params: Option, + ret_type: Option, +) -> Option { + let mut args = Vec::new(); + let mut bindings = Vec::new(); + if let Some(params) = params { + let mut param_types = Vec::new(); + for param in params.params() { + let type_ref = TypeRef::from_ast_opt(&ctx, param.ty()); + param_types.push(type_ref); + } + let arg = GenericArg::Type(TypeRef::Tuple(param_types)); + args.push(arg); + } + if let Some(ret_type) = ret_type { + let type_ref = TypeRef::from_ast_opt(&ctx, ret_type.ty()); + bindings.push(AssociatedTypeBinding { + name: name![Output], + type_ref: Some(type_ref), + bounds: Vec::new(), + }); + } + if args.is_empty() && bindings.is_empty() { + None + } else { + Some(GenericArgs { args, has_self_type: false, bindings }) + } +} diff --git a/crates/hir_def/src/path/lower/lower_use.rs b/crates/hir_def/src/path/lower/lower_use.rs new file mode 100644 index 000000000..53cecb05f --- /dev/null +++ b/crates/hir_def/src/path/lower/lower_use.rs @@ -0,0 +1,120 @@ +//! Lowers a single complex use like `use foo::{bar, baz};` into a list of paths like +//! `foo::bar`, `foo::baz`; + +use std::iter; + +use either::Either; +use hir_expand::{hygiene::Hygiene, name::AsName}; +use syntax::ast::{self, NameOwner}; +use test_utils::mark; + +use crate::path::{ImportAlias, ModPath, PathKind}; + +pub(crate) fn lower_use_tree( + prefix: Option, + tree: ast::UseTree, + hygiene: &Hygiene, + cb: &mut dyn FnMut(ModPath, &ast::UseTree, bool, Option), +) { + if let Some(use_tree_list) = tree.use_tree_list() { + let prefix = match tree.path() { + // E.g. use something::{{{inner}}}; + None => prefix, + // E.g. `use something::{inner}` (prefix is `None`, path is `something`) + // or `use something::{path::{inner::{innerer}}}` (prefix is `something::path`, path is `inner`) + Some(path) => match convert_path(prefix, path, hygiene) { + Some(it) => Some(it), + None => return, // FIXME: report errors somewhere + }, + }; + for child_tree in use_tree_list.use_trees() { + lower_use_tree(prefix.clone(), child_tree, hygiene, cb); + } + } else { + let alias = tree.rename().map(|a| { + a.name().map(|it| it.as_name()).map_or(ImportAlias::Underscore, ImportAlias::Alias) + }); + let is_glob = tree.star_token().is_some(); + if let Some(ast_path) = tree.path() { + // Handle self in a path. + // E.g. `use something::{self, <...>}` + if ast_path.qualifier().is_none() { + if let Some(segment) = ast_path.segment() { + if segment.kind() == Some(ast::PathSegmentKind::SelfKw) { + if let Some(prefix) = prefix { + cb(prefix, &tree, false, alias); + return; + } + } + } + } + if let Some(path) = convert_path(prefix, ast_path, hygiene) { + cb(path, &tree, is_glob, alias) + } + // FIXME: report errors somewhere + // We get here if we do + } else if is_glob { + mark::hit!(glob_enum_group); + if let Some(prefix) = prefix { + cb(prefix, &tree, is_glob, None) + } + } + } +} + +fn convert_path(prefix: Option, path: ast::Path, hygiene: &Hygiene) -> Option { + let prefix = if let Some(qual) = path.qualifier() { + Some(convert_path(prefix, qual, hygiene)?) + } else { + prefix + }; + + let segment = path.segment()?; + let res = match segment.kind()? { + ast::PathSegmentKind::Name(name_ref) => { + match hygiene.name_ref_to_name(name_ref) { + Either::Left(name) => { + // no type args in use + let mut res = prefix.unwrap_or_else(|| ModPath { + kind: PathKind::Plain, + segments: Vec::with_capacity(1), + }); + res.segments.push(name); + res + } + Either::Right(crate_id) => { + return Some(ModPath::from_segments( + PathKind::DollarCrate(crate_id), + iter::empty(), + )) + } + } + } + ast::PathSegmentKind::CrateKw => { + if prefix.is_some() { + return None; + } + ModPath::from_segments(PathKind::Crate, iter::empty()) + } + ast::PathSegmentKind::SelfKw => { + if prefix.is_some() { + return None; + } + ModPath::from_segments(PathKind::Super(0), iter::empty()) + } + ast::PathSegmentKind::SuperKw => { + let nested_super_count = match prefix.map(|p| p.kind) { + Some(PathKind::Super(n)) => n, + Some(_) => return None, + None => 0, + }; + + ModPath::from_segments(PathKind::Super(nested_super_count + 1), iter::empty()) + } + ast::PathSegmentKind::Type { .. } => { + // not allowed in imports + return None; + } + }; + Some(res) +} -- cgit v1.2.3