196 lines
6.9 KiB
Rust
196 lines
6.9 KiB
Rust
//! See [`PathTransform`].
|
|
|
|
use crate::helpers::mod_path_to_ast;
|
|
use hir::{HirDisplay, SemanticsScope};
|
|
use rustc_hash::FxHashMap;
|
|
use syntax::{
|
|
ast::{self, AstNode},
|
|
ted, SyntaxNode,
|
|
};
|
|
|
|
/// `PathTransform` substitutes path in SyntaxNodes in bulk.
|
|
///
|
|
/// This is mostly useful for IDE code generation. If you paste some existing
|
|
/// code into a new context (for example, to add method overrides to an `impl`
|
|
/// block), you generally want to appropriately qualify the names, and sometimes
|
|
/// you might want to substitute generic parameters as well:
|
|
///
|
|
/// ```
|
|
/// mod x {
|
|
/// pub struct A<V>;
|
|
/// pub trait T<U> { fn foo(&self, _: U) -> A<U>; }
|
|
/// }
|
|
///
|
|
/// mod y {
|
|
/// use x::T;
|
|
///
|
|
/// impl T<()> for () {
|
|
/// // If we invoke **Add Missing Members** here, we want to copy-paste `foo`.
|
|
/// // But we want a slightly-modified version of it:
|
|
/// fn foo(&self, _: ()) -> x::A<()> {}
|
|
/// }
|
|
/// }
|
|
/// ```
|
|
pub struct PathTransform<'a> {
|
|
generic_def: hir::GenericDef,
|
|
substs: Vec<ast::Type>,
|
|
target_scope: &'a SemanticsScope<'a>,
|
|
source_scope: &'a SemanticsScope<'a>,
|
|
}
|
|
|
|
impl<'a> PathTransform<'a> {
|
|
pub fn trait_impl(
|
|
target_scope: &'a SemanticsScope<'a>,
|
|
source_scope: &'a SemanticsScope<'a>,
|
|
trait_: hir::Trait,
|
|
impl_: ast::Impl,
|
|
) -> PathTransform<'a> {
|
|
PathTransform {
|
|
source_scope,
|
|
target_scope,
|
|
generic_def: trait_.into(),
|
|
substs: get_syntactic_substs(impl_).unwrap_or_default(),
|
|
}
|
|
}
|
|
|
|
pub fn function_call(
|
|
target_scope: &'a SemanticsScope<'a>,
|
|
source_scope: &'a SemanticsScope<'a>,
|
|
function: hir::Function,
|
|
generic_arg_list: ast::GenericArgList,
|
|
) -> PathTransform<'a> {
|
|
PathTransform {
|
|
source_scope,
|
|
target_scope,
|
|
generic_def: function.into(),
|
|
substs: get_type_args_from_arg_list(generic_arg_list).unwrap_or_default(),
|
|
}
|
|
}
|
|
|
|
pub fn apply(&self, syntax: &SyntaxNode) {
|
|
if let Some(ctx) = self.build_ctx() {
|
|
ctx.apply(syntax)
|
|
}
|
|
}
|
|
|
|
fn build_ctx(&self) -> Option<Ctx<'a>> {
|
|
let db = self.source_scope.db;
|
|
let target_module = self.target_scope.module()?;
|
|
let source_module = self.source_scope.module()?;
|
|
let skip = match self.generic_def {
|
|
// this is a trait impl, so we need to skip the first type parameter -- this is a bit hacky
|
|
hir::GenericDef::Trait(_) => 1,
|
|
_ => 0,
|
|
};
|
|
let substs_by_param: FxHashMap<_, _> = self
|
|
.generic_def
|
|
.type_params(db)
|
|
.into_iter()
|
|
.skip(skip)
|
|
// The actual list of trait type parameters may be longer than the one
|
|
// used in the `impl` block due to trailing default type parameters.
|
|
// For that case we extend the `substs` with an empty iterator so we
|
|
// can still hit those trailing values and check if they actually have
|
|
// a default type. If they do, go for that type from `hir` to `ast` so
|
|
// the resulting change can be applied correctly.
|
|
.zip(self.substs.iter().map(Some).chain(std::iter::repeat(None)))
|
|
.filter_map(|(k, v)| match v {
|
|
Some(v) => Some((k, v.clone())),
|
|
None => {
|
|
let default = k.default(db)?;
|
|
Some((
|
|
k,
|
|
ast::make::ty(&default.display_source_code(db, source_module.into()).ok()?),
|
|
))
|
|
}
|
|
})
|
|
.collect();
|
|
let res = Ctx { substs: substs_by_param, target_module, source_scope: self.source_scope };
|
|
Some(res)
|
|
}
|
|
}
|
|
|
|
struct Ctx<'a> {
|
|
substs: FxHashMap<hir::TypeParam, ast::Type>,
|
|
target_module: hir::Module,
|
|
source_scope: &'a SemanticsScope<'a>,
|
|
}
|
|
|
|
impl<'a> Ctx<'a> {
|
|
fn apply(&self, item: &SyntaxNode) {
|
|
for event in item.preorder() {
|
|
let node = match event {
|
|
syntax::WalkEvent::Enter(_) => continue,
|
|
syntax::WalkEvent::Leave(it) => it,
|
|
};
|
|
if let Some(path) = ast::Path::cast(node.clone()) {
|
|
self.transform_path(path);
|
|
}
|
|
}
|
|
}
|
|
fn transform_path(&self, path: ast::Path) -> Option<()> {
|
|
if path.qualifier().is_some() {
|
|
return None;
|
|
}
|
|
if path.segment().map_or(false, |s| {
|
|
s.param_list().is_some() || (s.self_token().is_some() && path.parent_path().is_none())
|
|
}) {
|
|
// don't try to qualify `Fn(Foo) -> Bar` paths, they are in prelude anyway
|
|
// don't try to qualify sole `self` either, they are usually locals, but are returned as modules due to namespace clashing
|
|
return None;
|
|
}
|
|
|
|
let resolution = self.source_scope.speculative_resolve(&path)?;
|
|
|
|
match resolution {
|
|
hir::PathResolution::TypeParam(tp) => {
|
|
if let Some(subst) = self.substs.get(&tp) {
|
|
ted::replace(path.syntax(), subst.clone_subtree().clone_for_update().syntax())
|
|
}
|
|
}
|
|
hir::PathResolution::Def(def) => {
|
|
let found_path =
|
|
self.target_module.find_use_path(self.source_scope.db.upcast(), def)?;
|
|
let res = mod_path_to_ast(&found_path).clone_for_update();
|
|
if let Some(args) = path.segment().and_then(|it| it.generic_arg_list()) {
|
|
if let Some(segment) = res.segment() {
|
|
let old = segment.get_or_create_generic_arg_list();
|
|
ted::replace(old.syntax(), args.clone_subtree().syntax().clone_for_update())
|
|
}
|
|
}
|
|
ted::replace(path.syntax(), res.syntax())
|
|
}
|
|
hir::PathResolution::Local(_)
|
|
| hir::PathResolution::ConstParam(_)
|
|
| hir::PathResolution::SelfType(_)
|
|
| hir::PathResolution::Macro(_)
|
|
| hir::PathResolution::AssocItem(_) => (),
|
|
}
|
|
Some(())
|
|
}
|
|
}
|
|
|
|
// FIXME: It would probably be nicer if we could get this via HIR (i.e. get the
|
|
// trait ref, and then go from the types in the substs back to the syntax).
|
|
fn get_syntactic_substs(impl_def: ast::Impl) -> Option<Vec<ast::Type>> {
|
|
let target_trait = impl_def.trait_()?;
|
|
let path_type = match target_trait {
|
|
ast::Type::PathType(path) => path,
|
|
_ => return None,
|
|
};
|
|
let generic_arg_list = path_type.path()?.segment()?.generic_arg_list()?;
|
|
|
|
get_type_args_from_arg_list(generic_arg_list)
|
|
}
|
|
|
|
fn get_type_args_from_arg_list(generic_arg_list: ast::GenericArgList) -> Option<Vec<ast::Type>> {
|
|
let mut result = Vec::new();
|
|
for generic_arg in generic_arg_list.generic_args() {
|
|
if let ast::GenericArg::TypeArg(type_arg) = generic_arg {
|
|
result.push(type_arg.ty()?)
|
|
}
|
|
}
|
|
|
|
Some(result)
|
|
}
|