SSR: Fix for path resolution of locals

It seems that Semantics::scope, if given a statement node, won't resolve
locals that were defined in the current scope, only in parent scopes.
Not sure if this is intended / expected behavior, but we work around it
for now by finding another nearby node to use as the scope (e.g. the
expression inside the EXPR_STMT).
This commit is contained in:
David Lattimore 2020-07-26 17:43:47 +10:00
parent bb587fae1d
commit b3ca36b2d9
2 changed files with 65 additions and 0 deletions

View file

@ -152,6 +152,7 @@ impl<'db> ResolutionScope<'db> {
.left_biased()
.map(|token| token.parent())
.unwrap_or_else(|| file.syntax().clone());
let node = pick_node_for_resolution(node);
let scope = sema.scope(&node);
ResolutionScope {
scope,
@ -185,6 +186,33 @@ impl<'db> ResolutionScope<'db> {
}
}
/// Returns a suitable node for resolving paths in the current scope. If we create a scope based on
/// a statement node, then we can't resolve local variables that were defined in the current scope
/// (only in parent scopes). So we find another node, ideally a child of the statement where local
/// variable resolution is permitted.
fn pick_node_for_resolution(node: SyntaxNode) -> SyntaxNode {
match node.kind() {
SyntaxKind::EXPR_STMT => {
if let Some(n) = node.first_child() {
mark::hit!(cursor_after_semicolon);
return n;
}
}
SyntaxKind::LET_STMT | SyntaxKind::BIND_PAT => {
if let Some(next) = node.next_sibling() {
return pick_node_for_resolution(next);
}
}
SyntaxKind::NAME => {
if let Some(parent) = node.parent() {
return pick_node_for_resolution(parent);
}
}
_ => {}
}
node
}
/// Returns whether `path` or any of its qualifiers contains type arguments.
fn path_contains_type_arguments(path: Option<ast::Path>) -> bool {
if let Some(path) = path {

View file

@ -885,3 +885,40 @@ fn ufcs_matches_method_call() {
"#]],
);
}
#[test]
fn replace_local_variable_reference() {
// The pattern references a local variable `foo` in the block containing the cursor. We should
// only replace references to this variable `foo`, not other variables that just happen to have
// the same name.
mark::check!(cursor_after_semicolon);
assert_ssr_transform(
"foo + $a ==>> $a - foo",
r#"
fn bar1() -> i32 {
let mut res = 0;
let foo = 5;
res += foo + 1;
let foo = 10;
res += foo + 2;<|>
res += foo + 3;
let foo = 15;
res += foo + 4;
res
}
"#,
expect![[r#"
fn bar1() -> i32 {
let mut res = 0;
let foo = 5;
res += foo + 1;
let foo = 10;
res += 2 - foo;
res += 3 - foo;
let foo = 15;
res += foo + 4;
res
}
"#]],
)
}