diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index da31787450..3b418fe6e8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -163,10 +163,7 @@ jobs:
     timeout-minutes: 45
     steps:
       - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: nightly-2025-05-16  # https://github.com/rust-lang/miri/issues/4323
-          components: miri, rust-src
+      - uses: dtolnay/rust-toolchain@miri
       - run: cargo miri setup
       - run: cargo miri test --all-features ${{github.event_name == 'pull_request' && '--tests' || ''}}
         env:
diff --git a/Cargo.toml b/Cargo.toml
index e024848f39..65f5fb1d7e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "syn"
-version = "2.0.104"
+version = "2.0.105"
 authors = ["David Tolnay <dtolnay@gmail.com>"]
 categories = ["development-tools::procedural-macro-helpers", "parser-implementations"]
 description = "Parser for Rust source code"
diff --git a/benches/rust.rs b/benches/rust.rs
index d0abce5c9e..b5edab1272 100644
--- a/benches/rust.rs
+++ b/benches/rust.rs
@@ -59,10 +59,9 @@ mod librustc_parse {
     extern crate rustc_span;
 
     use crate::repo;
-    use rustc_error_messages::FluentBundle;
     use rustc_errors::emitter::Emitter;
     use rustc_errors::registry::Registry;
-    use rustc_errors::translation::Translate;
+    use rustc_errors::translation::Translator;
     use rustc_errors::{DiagCtxt, DiagInner};
     use rustc_session::parse::ParseSess;
     use rustc_span::source_map::{FilePathMapping, SourceMap};
@@ -78,13 +77,7 @@ mod librustc_parse {
             fn source_map(&self) -> Option<&SourceMap> {
                 None
             }
-        }
-
-        impl Translate for SilentEmitter {
-            fn fluent_bundle(&self) -> Option<&FluentBundle> {
-                None
-            }
-            fn fallback_fluent_bundle(&self) -> &FluentBundle {
+            fn translator(&self) -> &Translator {
                 panic!("silent emitter attempted to translate a diagnostic");
             }
         }
diff --git a/codegen/Cargo.toml b/codegen/Cargo.toml
index b31b126894..bf010b80d7 100644
--- a/codegen/Cargo.toml
+++ b/codegen/Cargo.toml
@@ -24,7 +24,7 @@ serde = "1.0.88"
 serde_json = "1.0.38"
 syn = { version = "2", features = ["derive", "full", "parsing", "printing"], default-features = false }
 syn-codegen = { path = "../json", default-features = false }
-toml = { version = "0.8", default-features = false, features = ["parse"] }
+toml = { version = "0.9", default-features = false, features = ["parse", "serde"] }
 
 [workspace]
 [patch.crates-io]
diff --git a/codegen/src/parse.rs b/codegen/src/parse.rs
index 06afd7ddc7..3d6ba4c8e8 100644
--- a/codegen/src/parse.rs
+++ b/codegen/src/parse.rs
@@ -185,7 +185,7 @@ fn introspect_type(item: &syn::Type, lookup: &Lookup) -> types::Type {
             if mac.path.segments.last().unwrap().ident == "Token" =>
         {
             let content = mac.tokens.to_string();
-            let ty = lookup.tokens.get(&content).unwrap().to_string();
+            let ty = lookup.tokens.get(&content).unwrap().clone();
 
             types::Type::Token(ty)
         }
@@ -422,7 +422,7 @@ mod parsing {
             expansion.parse::<Token![$]>()?;
             let path: Path = expansion.parse()?;
             let ty = path.segments.last().unwrap().ident.to_string();
-            tokens.insert(token, ty.to_string());
+            tokens.insert(token, ty.clone());
         }
         Ok(tokens)
     }
diff --git a/src/item.rs b/src/item.rs
index a24623edb6..0b7707bf8c 100644
--- a/src/item.rs
+++ b/src/item.rs
@@ -2593,7 +2593,6 @@ pub(crate) mod parsing {
             input.parse::<Token![const]>()?;
         }
 
-        let begin = input.fork();
         let polarity = if input.peek(Token![!]) && !input.peek2(token::Brace) {
             Some(input.parse::<Token![!]>()?)
         } else {
@@ -2631,13 +2630,14 @@ pub(crate) mod parsing {
                 trait_ = None;
             }
             self_ty = input.parse()?;
+        } else if let Some(polarity) = polarity {
+            return Err(Error::new(
+                polarity.span,
+                "inherent impls cannot be negative",
+            ));
         } else {
             trait_ = None;
-            self_ty = if polarity.is_none() {
-                first_ty
-            } else {
-                Type::Verbatim(verbatim::between(&begin, input))
-            };
+            self_ty = first_ty;
         }
 
         generics.where_clause = input.parse()?;
diff --git a/src/lib.rs b/src/lib.rs
index cdf4efbc19..1d2ccc310a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -249,7 +249,7 @@
 //!   dynamic library libproc_macro from rustc toolchain.
 
 // Syn types in rustdoc of other crates get linked to here.
-#![doc(html_root_url = "https://docs.rs/syn/2.0.104")]
+#![doc(html_root_url = "https://docs.rs/syn/2.0.105")]
 #![cfg_attr(docsrs, feature(doc_cfg))]
 #![deny(unsafe_op_in_unsafe_fn)]
 #![allow(non_camel_case_types)]
diff --git a/syn.json b/syn.json
index d955962a89..9263a62a39 100644
--- a/syn.json
+++ b/syn.json
@@ -1,5 +1,5 @@
 {
-  "version": "2.0.104",
+  "version": "2.0.105",
   "types": [
     {
       "ident": "Abi",
diff --git a/tests/common/eq.rs b/tests/common/eq.rs
index f8059a6e88..6df66de677 100644
--- a/tests/common/eq.rs
+++ b/tests/common/eq.rs
@@ -21,7 +21,6 @@ use rustc_ast::ast::AttrItem;
 use rustc_ast::ast::AttrKind;
 use rustc_ast::ast::AttrStyle;
 use rustc_ast::ast::Attribute;
-use rustc_ast::ast::BareFnTy;
 use rustc_ast::ast::BinOpKind;
 use rustc_ast::ast::BindingMode;
 use rustc_ast::ast::Block;
@@ -53,6 +52,7 @@ use rustc_ast::ast::Fn;
 use rustc_ast::ast::FnContract;
 use rustc_ast::ast::FnDecl;
 use rustc_ast::ast::FnHeader;
+use rustc_ast::ast::FnPtrTy;
 use rustc_ast::ast::FnRetTy;
 use rustc_ast::ast::FnSig;
 use rustc_ast::ast::ForLoopKind;
@@ -117,6 +117,7 @@ use rustc_ast::ast::Mutability;
 use rustc_ast::ast::NodeId;
 use rustc_ast::ast::NormalAttr;
 use rustc_ast::ast::Param;
+use rustc_ast::ast::Parens;
 use rustc_ast::ast::ParenthesizedArgs;
 use rustc_ast::ast::Pat;
 use rustc_ast::ast::PatField;
@@ -142,6 +143,7 @@ use rustc_ast::ast::StructRest;
 use rustc_ast::ast::Term;
 use rustc_ast::ast::Trait;
 use rustc_ast::ast::TraitBoundModifiers;
+use rustc_ast::ast::TraitImplHeader;
 use rustc_ast::ast::TraitObjectSyntax;
 use rustc_ast::ast::TraitRef;
 use rustc_ast::ast::Ty;
@@ -176,8 +178,8 @@ use rustc_ast::tokenstream::{
 };
 use rustc_data_structures::packed::Pu128;
 use rustc_span::source_map::Spanned;
-use rustc_span::symbol::{sym, Ident};
-use rustc_span::{ErrorGuaranteed, Span, Symbol, SyntaxContext, DUMMY_SP};
+use rustc_span::symbol::{sym, ByteSymbol, Ident, Symbol};
+use rustc_span::{ErrorGuaranteed, Span, SyntaxContext, DUMMY_SP};
 use std::borrow::Cow;
 use std::collections::HashMap;
 use std::hash::{BuildHasher, Hash};
@@ -318,6 +320,7 @@ spanless_eq_partial_eq!(str);
 spanless_eq_partial_eq!(String);
 spanless_eq_partial_eq!(Pu128);
 spanless_eq_partial_eq!(Symbol);
+spanless_eq_partial_eq!(ByteSymbol);
 spanless_eq_partial_eq!(CommentKind);
 spanless_eq_partial_eq!(Delimiter);
 spanless_eq_partial_eq!(InlineAsmOptions);
@@ -479,7 +482,6 @@ spanless_eq_struct!(AttrItem; unsafety path args tokens);
 spanless_eq_struct!(AttrTokenStream; 0);
 spanless_eq_struct!(Attribute; kind id style span);
 spanless_eq_struct!(AttrsTarget; attrs tokens);
-spanless_eq_struct!(BareFnTy; safety ext generic_params decl decl_span);
 spanless_eq_struct!(BindingMode; 0 1);
 spanless_eq_struct!(Block; stmts id rules span tokens);
 spanless_eq_struct!(Closure; binder capture_clause constness coroutine_kind movability fn_decl body !fn_decl_span !fn_arg_span);
@@ -497,16 +499,17 @@ spanless_eq_struct!(Fn; defaultness ident generics sig contract define_opaque bo
 spanless_eq_struct!(FnContract; requires ensures);
 spanless_eq_struct!(FnDecl; inputs output);
 spanless_eq_struct!(FnHeader; constness coroutine_kind safety ext);
+spanless_eq_struct!(FnPtrTy; safety ext generic_params decl decl_span);
 spanless_eq_struct!(FnSig; header decl span);
 spanless_eq_struct!(ForeignMod; extern_span safety abi items);
 spanless_eq_struct!(FormatArgPosition; index kind span);
-spanless_eq_struct!(FormatArgs; span template arguments uncooked_fmt_str);
+spanless_eq_struct!(FormatArgs; span template arguments uncooked_fmt_str is_source_literal);
 spanless_eq_struct!(FormatArgument; kind expr);
 spanless_eq_struct!(FormatOptions; width precision alignment fill sign alternate zero_pad debug_hex);
 spanless_eq_struct!(FormatPlaceholder; argument span format_trait format_options);
 spanless_eq_struct!(GenericParam; id ident attrs bounds is_placeholder kind !colon_span);
 spanless_eq_struct!(Generics; params where_clause span);
-spanless_eq_struct!(Impl; defaultness safety generics constness polarity of_trait self_ty items);
+spanless_eq_struct!(Impl; generics of_trait self_ty items);
 spanless_eq_struct!(InlineAsm; asm_macro template template_strs operands clobber_abis options line_spans);
 spanless_eq_struct!(InlineAsmSym; id qself path);
 spanless_eq_struct!(Item<K>; attrs id span vis kind !tokens);
@@ -528,15 +531,16 @@ spanless_eq_struct!(Pat; id kind span tokens);
 spanless_eq_struct!(PatField; ident pat is_shorthand attrs id span is_placeholder);
 spanless_eq_struct!(Path; span segments tokens);
 spanless_eq_struct!(PathSegment; ident id args);
-spanless_eq_struct!(PolyTraitRef; bound_generic_params modifiers trait_ref span);
+spanless_eq_struct!(PolyTraitRef; bound_generic_params modifiers trait_ref span parens);
 spanless_eq_struct!(QSelf; ty path_span position);
 spanless_eq_struct!(StaticItem; ident ty safety mutability expr define_opaque);
 spanless_eq_struct!(Stmt; id kind span);
 spanless_eq_struct!(StrLit; symbol suffix symbol_unescaped style span);
 spanless_eq_struct!(StructExpr; qself path fields rest);
 spanless_eq_struct!(Token; kind span);
-spanless_eq_struct!(Trait; safety is_auto ident generics bounds items);
+spanless_eq_struct!(Trait; constness safety is_auto ident generics bounds items);
 spanless_eq_struct!(TraitBoundModifiers; constness asyncness polarity);
+spanless_eq_struct!(TraitImplHeader; defaultness safety constness polarity trait_ref);
 spanless_eq_struct!(TraitRef; path ref_id);
 spanless_eq_struct!(Ty; id kind span tokens);
 spanless_eq_struct!(TyAlias; defaultness ident generics where_clauses bounds ty);
@@ -561,7 +565,7 @@ spanless_eq_enum!(AttrStyle; Outer Inner);
 spanless_eq_enum!(AttrTokenTree; Token(0 1) Delimited(0 1 2 3) AttrsTarget(0));
 spanless_eq_enum!(BinOpKind; Add Sub Mul Div Rem And Or BitXor BitAnd BitOr Shl Shr Eq Lt Le Ne Ge Gt);
 spanless_eq_enum!(BlockCheckMode; Default Unsafe(0));
-spanless_eq_enum!(BorrowKind; Ref Raw);
+spanless_eq_enum!(BorrowKind; Ref Raw Pin);
 spanless_eq_enum!(BoundAsyncness; Normal Async(0));
 spanless_eq_enum!(BoundConstness; Never Always(0) Maybe(0));
 spanless_eq_enum!(BoundPolarity; Positive Negative(0) Maybe(0));
@@ -587,7 +591,7 @@ spanless_eq_enum!(GenBlockKind; Async Gen AsyncGen);
 spanless_eq_enum!(GenericArg; Lifetime(0) Type(0) Const(0));
 spanless_eq_enum!(GenericArgs; AngleBracketed(0) Parenthesized(0) ParenthesizedElided(0));
 spanless_eq_enum!(GenericBound; Trait(0) Outlives(0) Use(0 1));
-spanless_eq_enum!(GenericParamKind; Lifetime Type(default) Const(ty kw_span default));
+spanless_eq_enum!(GenericParamKind; Lifetime Type(default) Const(ty span default));
 spanless_eq_enum!(ImplPolarity; Positive Negative(0));
 spanless_eq_enum!(Inline; Yes No);
 spanless_eq_enum!(InlineAsmRegOrRegClass; Reg(0) RegClass(0));
@@ -604,6 +608,7 @@ spanless_eq_enum!(MetaItemInner; MetaItem(0) Lit(0));
 spanless_eq_enum!(ModKind; Loaded(0 1 2 3) Unloaded);
 spanless_eq_enum!(Movability; Static Movable);
 spanless_eq_enum!(Mutability; Mut Not);
+spanless_eq_enum!(Parens; Yes No);
 spanless_eq_enum!(PatFieldsRest; Rest Recovered(0) None);
 spanless_eq_enum!(PreciseCapturingArg; Lifetime(0) Arg(0 1));
 spanless_eq_enum!(RangeEnd; Included(0) Excluded);
@@ -615,7 +620,7 @@ spanless_eq_enum!(StrStyle; Cooked Raw(0));
 spanless_eq_enum!(StructRest; Base(0) Rest(0) None);
 spanless_eq_enum!(Term; Ty(0) Const(0));
 spanless_eq_enum!(TokenTree; Token(0 1) Delimited(0 1 2 3));
-spanless_eq_enum!(TraitObjectSyntax; Dyn DynStar None);
+spanless_eq_enum!(TraitObjectSyntax; Dyn None);
 spanless_eq_enum!(TyPatKind; Range(0 1 2) Or(0) Err(0));
 spanless_eq_enum!(UintTy; Usize U8 U16 U32 U64 U128);
 spanless_eq_enum!(UnOp; Deref Not Neg);
@@ -653,7 +658,7 @@ spanless_eq_enum!(PatKind; Missing Wild Ident(0 1 2) Struct(0 1 2 3)
     TupleStruct(0 1 2) Or(0) Path(0 1) Tuple(0) Box(0) Deref(0) Ref(0 1) Expr(0)
     Range(0 1 2) Slice(0) Rest Never Guard(0 1) Paren(0) MacCall(0) Err(0));
 spanless_eq_enum!(TyKind; Slice(0) Array(0 1) Ptr(0) Ref(0 1) PinnedRef(0 1)
-    BareFn(0) UnsafeBinder(0) Never Tup(0) Path(0 1) TraitObject(0 1)
+    FnPtr(0) UnsafeBinder(0) Never Tup(0) Path(0 1) TraitObject(0 1)
     ImplTrait(0 1) Paren(0) Typeof(0) Infer ImplicitSelf MacCall(0) CVarArgs
     Pat(0 1) Dummy Err(0));
 
diff --git a/tests/macros/mod.rs b/tests/macros/mod.rs
index 024075c046..9c9a957f71 100644
--- a/tests/macros/mod.rs
+++ b/tests/macros/mod.rs
@@ -1,11 +1,3 @@
-#![allow(unused_macros, unused_macro_rules)]
-
-#[path = "../debug/mod.rs"]
-pub mod debug;
-
-use std::str::FromStr;
-use syn::parse::Result;
-
 macro_rules! errorf {
     ($($tt:tt)*) => {{
         use ::std::io::Write;
@@ -13,81 +5,3 @@ macro_rules! errorf {
         write!(stderr.lock(), $($tt)*).unwrap();
     }};
 }
-
-macro_rules! punctuated {
-    ($($e:expr,)+) => {{
-        let mut seq = ::syn::punctuated::Punctuated::new();
-        $(
-            seq.push($e);
-        )+
-        seq
-    }};
-
-    ($($e:expr),+) => {
-        punctuated!($($e,)+)
-    };
-}
-
-macro_rules! snapshot {
-    ($($args:tt)*) => {
-        snapshot_impl!(() $($args)*)
-    };
-}
-
-macro_rules! snapshot_impl {
-    (($expr:ident) as $t:ty, @$snapshot:literal) => {
-        let tokens = crate::macros::TryIntoTokens::try_into_tokens($expr).unwrap();
-        let $expr: $t = syn::parse_quote!(#tokens);
-        let debug = crate::macros::debug::Lite(&$expr);
-        if !cfg!(miri) {
-            #[allow(clippy::needless_raw_string_hashes)] // https://github.com/mitsuhiko/insta/issues/389
-            {
-                insta::assert_debug_snapshot!(debug, @$snapshot);
-            }
-        }
-    };
-    (($($expr:tt)*) as $t:ty, @$snapshot:literal) => {{
-        let tokens = crate::macros::TryIntoTokens::try_into_tokens($($expr)*).unwrap();
-        let syntax_tree: $t = syn::parse_quote!(#tokens);
-        let debug = crate::macros::debug::Lite(&syntax_tree);
-        if !cfg!(miri) {
-            #[allow(clippy::needless_raw_string_hashes)]
-            {
-                insta::assert_debug_snapshot!(debug, @$snapshot);
-            }
-        }
-        syntax_tree
-    }};
-    (($($expr:tt)*) , @$snapshot:literal) => {{
-        let syntax_tree = $($expr)*;
-        let debug = crate::macros::debug::Lite(&syntax_tree);
-        if !cfg!(miri) {
-            #[allow(clippy::needless_raw_string_hashes)]
-            {
-                insta::assert_debug_snapshot!(debug, @$snapshot);
-            }
-        }
-        syntax_tree
-    }};
-    (($($expr:tt)*) $next:tt $($rest:tt)*) => {
-        snapshot_impl!(($($expr)* $next) $($rest)*)
-    };
-}
-
-pub trait TryIntoTokens {
-    #[allow(dead_code)]
-    fn try_into_tokens(self) -> Result<proc_macro2::TokenStream>;
-}
-
-impl TryIntoTokens for &str {
-    fn try_into_tokens(self) -> Result<proc_macro2::TokenStream> {
-        let tokens = proc_macro2::TokenStream::from_str(self)?;
-        Ok(tokens)
-    }
-}
-
-impl TryIntoTokens for proc_macro2::TokenStream {
-    fn try_into_tokens(self) -> Result<proc_macro2::TokenStream> {
-        Ok(self)
-    }
-}
diff --git a/tests/repo/mod.rs b/tests/repo/mod.rs
index 81b29e2a0c..81573456cd 100644
--- a/tests/repo/mod.rs
+++ b/tests/repo/mod.rs
@@ -222,7 +222,11 @@ static EXCLUDE_FILES: &[&str] = &[
     // Rustc bug: https://github.com/rust-lang/rust/issues/132080
     "src/tools/rust-analyzer/crates/parser/test_data/parser/ok/0073_safe_declarations_in_extern_blocks.rs",
 
-    // Compile-fail expr parameter in const generic position: f::<1 + 2>()
+    // Negative inherent impl: `impl !Box<JoinHandle> {}`
+    "src/tools/rustfmt/tests/source/negative-impl.rs",
+    "src/tools/rustfmt/tests/target/negative-impl.rs",
+
+    // Compile-fail expr parameter in const generic position: `f::<1 + 2>()`
     "tests/ui/const-generics/early/closing-args-token.rs",
     "tests/ui/const-generics/early/const-expression-parameter.rs",
 
diff --git a/tests/snapshot/mod.rs b/tests/snapshot/mod.rs
new file mode 100644
index 0000000000..98d2aebc9d
--- /dev/null
+++ b/tests/snapshot/mod.rs
@@ -0,0 +1,68 @@
+#![allow(unused_macros, unused_macro_rules)]
+
+use std::str::FromStr;
+use syn::parse::Result;
+
+macro_rules! snapshot {
+    ($($args:tt)*) => {
+        snapshot_impl!(() $($args)*)
+    };
+}
+
+macro_rules! snapshot_impl {
+    (($expr:ident) as $t:ty, @$snapshot:literal) => {
+        let tokens = crate::snapshot::TryIntoTokens::try_into_tokens($expr).unwrap();
+        let $expr: $t = syn::parse_quote!(#tokens);
+        let debug = crate::debug::Lite(&$expr);
+        if !cfg!(miri) {
+            #[allow(clippy::needless_raw_string_hashes)] // https://github.com/mitsuhiko/insta/issues/389
+            {
+                insta::assert_debug_snapshot!(debug, @$snapshot);
+            }
+        }
+    };
+    (($($expr:tt)*) as $t:ty, @$snapshot:literal) => {{
+        let tokens = crate::snapshot::TryIntoTokens::try_into_tokens($($expr)*).unwrap();
+        let syntax_tree: $t = syn::parse_quote!(#tokens);
+        let debug = crate::debug::Lite(&syntax_tree);
+        if !cfg!(miri) {
+            #[allow(clippy::needless_raw_string_hashes)]
+            {
+                insta::assert_debug_snapshot!(debug, @$snapshot);
+            }
+        }
+        syntax_tree
+    }};
+    (($($expr:tt)*) , @$snapshot:literal) => {{
+        let syntax_tree = $($expr)*;
+        let debug = crate::debug::Lite(&syntax_tree);
+        if !cfg!(miri) {
+            #[allow(clippy::needless_raw_string_hashes)]
+            {
+                insta::assert_debug_snapshot!(debug, @$snapshot);
+            }
+        }
+        syntax_tree
+    }};
+    (($($expr:tt)*) $next:tt $($rest:tt)*) => {
+        snapshot_impl!(($($expr)* $next) $($rest)*)
+    };
+}
+
+pub trait TryIntoTokens {
+    #[allow(dead_code)]
+    fn try_into_tokens(self) -> Result<proc_macro2::TokenStream>;
+}
+
+impl TryIntoTokens for &str {
+    fn try_into_tokens(self) -> Result<proc_macro2::TokenStream> {
+        let tokens = proc_macro2::TokenStream::from_str(self)?;
+        Ok(tokens)
+    }
+}
+
+impl TryIntoTokens for proc_macro2::TokenStream {
+    fn try_into_tokens(self) -> Result<proc_macro2::TokenStream> {
+        Ok(self)
+    }
+}
diff --git a/tests/test_asyncness.rs b/tests/test_asyncness.rs
index 09dbfc582c..c7aee3285b 100644
--- a/tests/test_asyncness.rs
+++ b/tests/test_asyncness.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use syn::{Expr, Item};
 
diff --git a/tests/test_attribute.rs b/tests/test_attribute.rs
index a19dd0b38f..81c485e6b2 100644
--- a/tests/test_attribute.rs
+++ b/tests/test_attribute.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use syn::parse::Parser;
 use syn::{Attribute, Meta};
diff --git a/tests/test_derive_input.rs b/tests/test_derive_input.rs
index 11467c7155..790e2792ad 100644
--- a/tests/test_derive_input.rs
+++ b/tests/test_derive_input.rs
@@ -8,7 +8,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use quote::quote;
 use syn::{Data, DeriveInput};
diff --git a/tests/test_expr.rs b/tests/test_expr.rs
index e23d0bd905..e21373cf96 100644
--- a/tests/test_expr.rs
+++ b/tests/test_expr.rs
@@ -13,8 +13,11 @@
 
 #[macro_use]
 mod macros;
+#[macro_use]
+mod snapshot;
 
 mod common;
+mod debug;
 
 use crate::common::visit::{AsIfPrinted, FlattenParens};
 use proc_macro2::{Delimiter, Group, Ident, Span, TokenStream};
@@ -900,9 +903,9 @@ fn test_fixup() {
             original == reconstructed,
             "original: {}\n{:#?}\nreconstructed: {}\n{:#?}",
             original.to_token_stream(),
-            crate::macros::debug::Lite(&original),
+            crate::debug::Lite(&original),
             reconstructed.to_token_stream(),
-            crate::macros::debug::Lite(&reconstructed),
+            crate::debug::Lite(&reconstructed),
         );
     }
 }
@@ -1663,7 +1666,7 @@ fn test_permutations() -> ExitCode {
             fail!(
                 "failed to parse: {}\n{:#?}",
                 tokens,
-                crate::macros::debug::Lite(&original),
+                crate::debug::Lite(&original),
             );
         };
         AsIfPrinted.visit_expr_mut(&mut original);
@@ -1672,9 +1675,9 @@ fn test_permutations() -> ExitCode {
             fail!(
                 "before: {}\n{:#?}\nafter: {}\n{:#?}",
                 tokens,
-                crate::macros::debug::Lite(&original),
+                crate::debug::Lite(&original),
                 parsed.to_token_stream(),
-                crate::macros::debug::Lite(&parsed),
+                crate::debug::Lite(&parsed),
             );
         }
         let mut tokens_no_paren = tokens.clone();
diff --git a/tests/test_generics.rs b/tests/test_generics.rs
index 4dc183c00c..c96a786644 100644
--- a/tests/test_generics.rs
+++ b/tests/test_generics.rs
@@ -7,7 +7,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use quote::quote;
 use syn::{DeriveInput, ItemFn, TypeParamBound, WhereClause, WherePredicate};
diff --git a/tests/test_grouping.rs b/tests/test_grouping.rs
index 5d4b62914d..b466c7e721 100644
--- a/tests/test_grouping.rs
+++ b/tests/test_grouping.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use proc_macro2::{Delimiter, Group, Literal, Punct, Spacing, TokenStream, TokenTree};
 use syn::Expr;
diff --git a/tests/test_item.rs b/tests/test_item.rs
index 0a12b7aadc..d9a7b5b6b0 100644
--- a/tests/test_item.rs
+++ b/tests/test_item.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use proc_macro2::{Delimiter, Group, Ident, Span, TokenStream, TokenTree};
 use quote::quote;
@@ -51,8 +53,6 @@ fn test_macro_variable_attr() {
 
 #[test]
 fn test_negative_impl() {
-    // Rustc parses all of the following.
-
     #[cfg(any())]
     impl ! {}
     let tokens = quote! {
@@ -65,18 +65,11 @@ fn test_negative_impl() {
     }
     "#);
 
-    #[cfg(any())]
-    #[rustfmt::skip]
-    impl !Trait {}
     let tokens = quote! {
         impl !Trait {}
     };
-    snapshot!(tokens as Item, @r#"
-    Item::Impl {
-        generics: Generics,
-        self_ty: Type::Verbatim(`! Trait`),
-    }
-    "#);
+    let err = syn::parse2::<Item>(tokens).unwrap_err();
+    assert_eq!(err.to_string(), "inherent impls cannot be negative");
 
     #[cfg(any())]
     impl !Trait for T {}
@@ -107,19 +100,6 @@ fn test_negative_impl() {
         },
     }
     "#);
-
-    #[cfg(any())]
-    #[rustfmt::skip]
-    impl !! {}
-    let tokens = quote! {
-        impl !! {}
-    };
-    snapshot!(tokens as Item, @r#"
-    Item::Impl {
-        generics: Generics,
-        self_ty: Type::Verbatim(`! !`),
-    }
-    "#);
 }
 
 #[test]
diff --git a/tests/test_iterators.rs b/tests/test_iterators.rs
index 525d77b1f3..57c21bf9f4 100644
--- a/tests/test_iterators.rs
+++ b/tests/test_iterators.rs
@@ -8,8 +8,19 @@
 use syn::punctuated::{Pair, Punctuated};
 use syn::{parse_quote, GenericParam, Generics, Lifetime, LifetimeParam, Token};
 
-#[macro_use]
-mod macros;
+macro_rules! punctuated {
+    ($($e:expr,)+) => {{
+        let mut seq = ::syn::punctuated::Punctuated::new();
+        $(
+            seq.push($e);
+        )+
+        seq
+    }};
+
+    ($($e:expr),+) => {
+        punctuated!($($e,)+)
+    };
+}
 
 macro_rules! check_exact_size_iterator {
     ($iter:expr) => {{
diff --git a/tests/test_lit.rs b/tests/test_lit.rs
index 6a7208a239..f2367b4416 100644
--- a/tests/test_lit.rs
+++ b/tests/test_lit.rs
@@ -9,7 +9,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use proc_macro2::{Delimiter, Group, Literal, Span, TokenStream, TokenTree};
 use quote::ToTokens;
diff --git a/tests/test_meta.rs b/tests/test_meta.rs
index 519b3ecf43..30d393c153 100644
--- a/tests/test_meta.rs
+++ b/tests/test_meta.rs
@@ -7,7 +7,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use syn::{Meta, MetaList, MetaNameValue};
 
diff --git a/tests/test_parse_quote.rs b/tests/test_parse_quote.rs
index 33665e068a..600870bab5 100644
--- a/tests/test_parse_quote.rs
+++ b/tests/test_parse_quote.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use syn::punctuated::Punctuated;
 use syn::{parse_quote, Attribute, Field, Lit, Pat, Stmt, Token};
diff --git a/tests/test_pat.rs b/tests/test_pat.rs
index 615de6a14b..f778928bc9 100644
--- a/tests/test_pat.rs
+++ b/tests/test_pat.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use proc_macro2::{Delimiter, Group, TokenStream, TokenTree};
 use quote::{quote, ToTokens as _};
diff --git a/tests/test_path.rs b/tests/test_path.rs
index 39aa91c08c..7f9e515d26 100644
--- a/tests/test_path.rs
+++ b/tests/test_path.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream, TokenTree};
 use quote::{quote, ToTokens};
diff --git a/tests/test_precedence.rs b/tests/test_precedence.rs
index 58d3a9891d..33af2746a9 100644
--- a/tests/test_precedence.rs
+++ b/tests/test_precedence.rs
@@ -264,7 +264,9 @@ fn librustc_parenthesize(mut librustc_expr: Box<ast::Expr>) -> Box<ast::Expr> {
                     fields,
                     rest,
                 } = expr.deref_mut();
-                vis.visit_qself(qself);
+                if let Some(qself) = qself {
+                    vis.visit_qself(qself);
+                }
                 vis.visit_path(path);
                 fields.flat_map_in_place(|field| flat_map_field(field, vis));
                 if let StructRest::Base(rest) = rest {
diff --git a/tests/test_receiver.rs b/tests/test_receiver.rs
index b0e2a91fa2..98194101fd 100644
--- a/tests/test_receiver.rs
+++ b/tests/test_receiver.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use syn::{parse_quote, TraitItemFn};
 
diff --git a/tests/test_shebang.rs b/tests/test_shebang.rs
index 20450b74e5..3b55ddfdd5 100644
--- a/tests/test_shebang.rs
+++ b/tests/test_shebang.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 #[test]
 fn test_basic() {
diff --git a/tests/test_stmt.rs b/tests/test_stmt.rs
index ba1e63af7c..101c1b1c90 100644
--- a/tests/test_stmt.rs
+++ b/tests/test_stmt.rs
@@ -7,7 +7,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use proc_macro2::{Delimiter, Group, Ident, Span, TokenStream, TokenTree};
 use quote::{quote, ToTokens as _};
diff --git a/tests/test_token_trees.rs b/tests/test_token_trees.rs
index 3dc3734cbc..1b473858cd 100644
--- a/tests/test_token_trees.rs
+++ b/tests/test_token_trees.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use proc_macro2::TokenStream;
 use quote::quote;
diff --git a/tests/test_ty.rs b/tests/test_ty.rs
index c85f592add..5f29220114 100644
--- a/tests/test_ty.rs
+++ b/tests/test_ty.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream, TokenTree};
 use quote::{quote, ToTokens as _};
diff --git a/tests/test_visibility.rs b/tests/test_visibility.rs
index 0bc98b15f8..cf15574b51 100644
--- a/tests/test_visibility.rs
+++ b/tests/test_visibility.rs
@@ -5,7 +5,9 @@
 )]
 
 #[macro_use]
-mod macros;
+mod snapshot;
+
+mod debug;
 
 use proc_macro2::{Delimiter, Group, Ident, Punct, Spacing, Span, TokenStream, TokenTree};
 use quote::quote;