From 92d33b718142b1f952aef5ab9e3b09adb0a26548 Mon Sep 17 00:00:00 2001
From: David Pedersen <david.pdrsn@gmail.com>
Date: Thu, 23 Mar 2023 23:38:59 +0100
Subject: [PATCH] macros: update syn (#5572)

---
 tokio-macros/Cargo.toml    |  2 +-
 tokio-macros/src/entry.rs  | 36 ++++++++++++++++--------------------
 tokio-macros/src/select.rs |  7 +++----
 3 files changed, 20 insertions(+), 25 deletions(-)

diff --git a/tokio-macros/Cargo.toml b/tokio-macros/Cargo.toml
index 79772bdb470..bec401c08a0 100644
--- a/tokio-macros/Cargo.toml
+++ b/tokio-macros/Cargo.toml
@@ -24,7 +24,7 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1.0.7"
 quote = "1"
-syn = { version = "1.0.56", features = ["full"] }
+syn = { version = "2.0", features = ["full"] }
 
 [dev-dependencies]
 tokio = { version = "1.0.0", path = "../tokio", features = ["full"] }
diff --git a/tokio-macros/src/entry.rs b/tokio-macros/src/entry.rs
index 0c14bfb77ba..3b124cff98e 100644
--- a/tokio-macros/src/entry.rs
+++ b/tokio-macros/src/entry.rs
@@ -4,7 +4,7 @@ use quote::{quote, quote_spanned, ToTokens};
 use syn::{parse::Parser, Ident, Path};
 
 // syn::AttributeArgs does not implement syn::Parse
-type AttributeArgs = syn::punctuated::Punctuated<syn::NestedMeta, syn::Token![,]>;
+type AttributeArgs = syn::punctuated::Punctuated<syn::Meta, syn::Token![,]>;
 
 #[derive(Clone, Copy, PartialEq)]
 enum RuntimeFlavor {
@@ -245,7 +245,7 @@ fn build_config(
 
     for arg in args {
         match arg {
-            syn::NestedMeta::Meta(syn::Meta::NameValue(namevalue)) => {
+            syn::Meta::NameValue(namevalue) => {
                 let ident = namevalue
                     .path
                     .get_ident()
@@ -254,34 +254,26 @@ fn build_config(
                     })?
                     .to_string()
                     .to_lowercase();
+                let lit = match &namevalue.value {
+                    syn::Expr::Lit(syn::ExprLit { lit, .. }) => lit,
+                    expr => return Err(syn::Error::new_spanned(expr, "Must be a literal")),
+                };
                 match ident.as_str() {
                     "worker_threads" => {
-                        config.set_worker_threads(
-                            namevalue.lit.clone(),
-                            syn::spanned::Spanned::span(&namevalue.lit),
-                        )?;
+                        config.set_worker_threads(lit.clone(), syn::spanned::Spanned::span(lit))?;
                     }
                     "flavor" => {
-                        config.set_flavor(
-                            namevalue.lit.clone(),
-                            syn::spanned::Spanned::span(&namevalue.lit),
-                        )?;
+                        config.set_flavor(lit.clone(), syn::spanned::Spanned::span(lit))?;
                     }
                     "start_paused" => {
-                        config.set_start_paused(
-                            namevalue.lit.clone(),
-                            syn::spanned::Spanned::span(&namevalue.lit),
-                        )?;
+                        config.set_start_paused(lit.clone(), syn::spanned::Spanned::span(lit))?;
                     }
                     "core_threads" => {
                         let msg = "Attribute `core_threads` is renamed to `worker_threads`";
                         return Err(syn::Error::new_spanned(namevalue, msg));
                     }
                     "crate" => {
-                        config.set_crate_name(
-                            namevalue.lit.clone(),
-                            syn::spanned::Spanned::span(&namevalue.lit),
-                        )?;
+                        config.set_crate_name(lit.clone(), syn::spanned::Spanned::span(lit))?;
                     }
                     name => {
                         let msg = format!(
@@ -292,7 +284,7 @@ fn build_config(
                     }
                 }
             }
-            syn::NestedMeta::Meta(syn::Meta::Path(path)) => {
+            syn::Meta::Path(path) => {
                 let name = path
                     .get_ident()
                     .ok_or_else(|| syn::Error::new_spanned(&path, "Must have specified ident"))?
@@ -478,7 +470,11 @@ pub(crate) fn test(args: TokenStream, item: TokenStream, rt_multi_thread: bool)
         Ok(it) => it,
         Err(e) => return token_stream_with_error(item, e),
     };
-    let config = if let Some(attr) = input.attrs.iter().find(|attr| attr.path.is_ident("test")) {
+    let config = if let Some(attr) = input
+        .attrs
+        .iter()
+        .find(|attr| attr.meta.path().is_ident("test"))
+    {
         let msg = "second test attribute is supplied";
         Err(syn::Error::new_spanned(attr, msg))
     } else {
diff --git a/tokio-macros/src/select.rs b/tokio-macros/src/select.rs
index 8c5ae306e67..dd491f848c3 100644
--- a/tokio-macros/src/select.rs
+++ b/tokio-macros/src/select.rs
@@ -1,7 +1,7 @@
 use proc_macro::{TokenStream, TokenTree};
 use proc_macro2::Span;
 use quote::quote;
-use syn::Ident;
+use syn::{parse::Parser, Ident};
 
 pub(crate) fn declare_output_enum(input: TokenStream) -> TokenStream {
     // passed in is: `(_ _ _)` with one `_` per branch
@@ -46,7 +46,7 @@ pub(crate) fn clean_pattern_macro(input: TokenStream) -> TokenStream {
     // If this isn't a pattern, we return the token stream as-is. The select!
     // macro is using it in a location requiring a pattern, so an error will be
     // emitted there.
-    let mut input: syn::Pat = match syn::parse(input.clone()) {
+    let mut input: syn::Pat = match syn::Pat::parse_single.parse(input.clone()) {
         Ok(it) => it,
         Err(_) => return input,
     };
@@ -58,7 +58,6 @@ pub(crate) fn clean_pattern_macro(input: TokenStream) -> TokenStream {
 // Removes any occurrences of ref or mut in the provided pattern.
 fn clean_pattern(pat: &mut syn::Pat) {
     match pat {
-        syn::Pat::Box(_box) => {}
         syn::Pat::Lit(_literal) => {}
         syn::Pat::Macro(_macro) => {}
         syn::Pat::Path(_path) => {}
@@ -94,7 +93,7 @@ fn clean_pattern(pat: &mut syn::Pat) {
             }
         }
         syn::Pat::TupleStruct(tuple) => {
-            for elem in tuple.pat.elems.iter_mut() {
+            for elem in tuple.elems.iter_mut() {
                 clean_pattern(elem);
             }
         }