Auto merge of rust-lang#16060 - Veykril:format-args-orphans, r=Veykril

fix: Fix completion failing in `format_args!` with invalid template

crates/hir-def/src/body/lower.rs

@@ -1611,7 +1611,11 @@ impl ExprCollector<'_> {
  }
  },
  ),
- None => FormatArgs { template: Default::default(), arguments: args.finish() },
+ None => FormatArgs {
+ template: Default::default(),
+ arguments: args.finish(),
+ orphans: Default::default(),
+ },
  };
 
  // Create a list of all _unique_ (argument, format trait) combinations.
@@ -1750,7 +1754,13 @@ impl ExprCollector<'_> {
  });
  let unsafe_arg_new = self.alloc_expr_desugared(Expr::Unsafe {
  id: None,
- statements: Box::default(),
+ // We collect the unused expressions here so that we still infer them instead of
+ // dropping them out of the expression tree
+ statements: fmt
+ .orphans
+ .into_iter()
+ .map(|expr| Statement::Expr { expr, has_semi: true })
+ .collect(),
  tail: Some(unsafe_arg_new),
  });
 

crates/hir-def/src/hir/format_args.rs

@@ -3,6 +3,7 @@ use std::mem;
 
 use hir_expand::name::Name;
 use rustc_dependencies::parse_format as parse;
+use stdx::TupleExt;
 use syntax::{
  ast::{self, IsString},
  SmolStr, TextRange, TextSize,
@@ -14,6 +15,7 @@ use crate::hir::ExprId;
 pub struct FormatArgs {
  pub template: Box<[FormatArgsPiece]>,
  pub arguments: FormatArguments,
+ pub orphans: Vec<ExprId>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -196,7 +198,11 @@ pub(crate) fn parse(
  let is_source_literal = parser.is_source_literal;
  if !parser.errors.is_empty() {
  // FIXME: Diagnose
- return FormatArgs { template: Default::default(), arguments: args.finish() };
+ return FormatArgs {
+ template: Default::default(),
+ arguments: args.finish(),
+ orphans: vec![],
+ };
  }
 
  let to_span = |inner_span: parse::InnerSpan| {
@@ -419,7 +425,11 @@ pub(crate) fn parse(
  // FIXME: Diagnose
  }
 
- FormatArgs { template: template.into_boxed_slice(), arguments: args.finish() }
+ FormatArgs {
+ template: template.into_boxed_slice(),
+ arguments: args.finish(),
+ orphans: unused.into_iter().map(TupleExt::head).collect(),
+ }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]

crates/ide-completion/src/tests/expression.rs

@@ -1094,3 +1094,157 @@ pub struct UnstableButWeAreOnNightlyAnyway;
  "#]],
  );
 }
+
+#[test]
+fn inside_format_args_completions_work() {
+ check_empty(
+ r#"
+//- minicore: fmt
+struct Foo;
+impl Foo {
+ fn foo(&self) {}
+}
+
+fn main() {
+ format_args!("{}", Foo.$0);
+}
+"#,
+ expect![[r#"
+ me foo() fn(&self)
+ sn box Box::new(expr)
+ sn call function(expr)
+ sn dbg dbg!(expr)
+ sn dbgr dbg!(&expr)
+ sn match match expr {}
+ sn ref &expr
+ sn refm &mut expr
+ sn unsafe unsafe {}
+ "#]],
+ );
+ check_empty(
+ r#"
+//- minicore: fmt
+struct Foo;
+impl Foo {
+ fn foo(&self) {}
+}
+
+fn main() {
+ format_args!("{}", Foo.f$0);
+}
+"#,
+ expect![[r#"
+ me foo() fn(&self)
+ sn box Box::new(expr)
+ sn call function(expr)
+ sn dbg dbg!(expr)
+ sn dbgr dbg!(&expr)
+ sn match match expr {}
+ sn ref &expr
+ sn refm &mut expr
+ sn unsafe unsafe {}
+ "#]],
+ );
+}
+
+#[test]
+fn inside_faulty_format_args_completions_work() {
+ check_empty(
+ r#"
+//- minicore: fmt
+struct Foo;
+impl Foo {
+ fn foo(&self) {}
+}
+
+fn main() {
+ format_args!("", Foo.$0);
+}
+"#,
+ expect![[r#"
+ me foo() fn(&self)
+ sn box Box::new(expr)
+ sn call function(expr)
+ sn dbg dbg!(expr)
+ sn dbgr dbg!(&expr)
+ sn match match expr {}
+ sn ref &expr
+ sn refm &mut expr
+ sn unsafe unsafe {}
+ "#]],
+ );
+ check_empty(
+ r#"
+//- minicore: fmt
+struct Foo;
+impl Foo {
+ fn foo(&self) {}
+}
+
+fn main() {
+ format_args!("", Foo.f$0);
+}
+"#,
+ expect![[r#"
+ me foo() fn(&self)
+ sn box Box::new(expr)
+ sn call function(expr)
+ sn dbg dbg!(expr)
+ sn dbgr dbg!(&expr)
+ sn match match expr {}
+ sn ref &expr
+ sn refm &mut expr
+ sn unsafe unsafe {}
+ "#]],
+ );
+ check_empty(
+ r#"
+//- minicore: fmt
+struct Foo;
+impl Foo {
+ fn foo(&self) {}
+}
+
+fn main() {
+ format_args!("{} {named} {captured} {named} {}", a, named = c, Foo.f$0);
+}
+"#,
+ expect![[r#"
+ me foo() fn(&self)
+ sn box Box::new(expr)
+ sn call function(expr)
+ sn dbg dbg!(expr)
+ sn dbgr dbg!(&expr)
+ sn match match expr {}
+ sn ref &expr
+ sn refm &mut expr
+ sn unsafe unsafe {}
+ "#]],
+ );
+ check_empty(
+ r#"
+//- minicore: fmt
+struct Foo;
+impl Foo {
+ fn foo(&self) {}
+}
+
+fn main() {
+ format_args!("{", Foo.f$0);
+}
+"#,
+ expect![[r#"
+ sn box Box::new(expr)
+ sn call function(expr)
+ sn dbg dbg!(expr)
+ sn dbgr dbg!(&expr)
+ sn if if expr {}
+ sn match match expr {}
+ sn not !expr
+ sn ref &expr
+ sn refm &mut expr
+ sn unsafe unsafe {}
+ sn while while expr {}
+ "#]],
+ );
+}

crates/ide/src/view_hir.rs

@@ -1,7 +1,7 @@
 use hir::{DefWithBody, Semantics};
 use ide_db::base_db::FilePosition;
 use ide_db::RootDatabase;
-use syntax::{algo::find_node_at_offset, ast, AstNode};
+use syntax::{algo::ancestors_at_offset, ast, AstNode};
 
 // Feature: View Hir
 //
@@ -19,7 +19,9 @@ fn body_hir(db: &RootDatabase, position: FilePosition) -> Option<String> {
  let sema = Semantics::new(db);
  let source_file = sema.parse(position.file_id);
 
- let item = find_node_at_offset::<ast::Item>(source_file.syntax(), position.offset)?;
+ let item = ancestors_at_offset(source_file.syntax(), position.offset)
+ .filter(|it| ast::MacroCall::can_cast(it.kind()))
+ .find_map(ast::Item::cast)?;
  let def: DefWithBody = match item {
  ast::Item::Fn(it) => sema.to_def(&it)?.into(),
  ast::Item::Const(it) => sema.to_def(&it)?.into(),

crates/ide/src/view_mir.rs

@@ -1,7 +1,7 @@
 use hir::{DefWithBody, Semantics};
 use ide_db::base_db::FilePosition;
 use ide_db::RootDatabase;
-use syntax::{algo::find_node_at_offset, ast, AstNode};
+use syntax::{algo::ancestors_at_offset, ast, AstNode};
 
 // Feature: View Mir
 //
@@ -18,7 +18,9 @@ fn body_mir(db: &RootDatabase, position: FilePosition) -> Option<String> {
  let sema = Semantics::new(db);
  let source_file = sema.parse(position.file_id);
 
- let item = find_node_at_offset::<ast::Item>(source_file.syntax(), position.offset)?;
+ let item = ancestors_at_offset(source_file.syntax(), position.offset)
+ .filter(|it| ast::MacroCall::can_cast(it.kind()))
+ .find_map(ast::Item::cast)?;
  let def: DefWithBody = match item {
  ast::Item::Fn(it) => sema.to_def(&it)?.into(),
  ast::Item::Const(it) => sema.to_def(&it)?.into(),

crates/rust-analyzer/tests/slow-tests/tidy.rs

@@ -250,6 +250,7 @@ fn check_dbg(path: &Path, text: &str) {
  // We have .dbg postfix
  "ide-completion/src/completions/postfix.rs",
  "ide-completion/src/completions/keyword.rs",
+ "ide-completion/src/tests/expression.rs",
  "ide-completion/src/tests/proc_macros.rs",
  // The documentation in string literals may contain anything for its own purposes
  "ide-completion/src/lib.rs",