Update syn requirement from 1.0.107 to 2.0.48 (#881)

* Update syn requirement from 1.0.107 to 2.0.48

Updates the requirements on [syn](https://github.com/dtolnay/syn) to permit the latest version.
- [Release notes](https://github.com/dtolnay/syn/releases)
- [Commits](https://github.com/dtolnay/syn/compare/1.0.107...2.0.48)

---
updated-dependencies:
- dependency-name: syn
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

* rtic-macros: attr.path -> attr.path()

* rtic-macros: tokens -> parse_args()

Fix parsing of InitArgs, IdleArgs, *Args

Including HardwareTaskArgs, SoftwareTaskArgs

* rtic-macros: Rename content to input

As syn2 removes the surrounding parenthesis as
part of parse_args() the distinction between
input and content is redundant

* rtic-macros: Handle removal of Expr::Type

Manually parse local_resources

With type ascription de-RFCd syn2 dropped
Expr::Type

* rtic-macros: Syn upgrade CHANGELOG

* rtic-macro: Retain most old errors as they were

Spans are not equal, but good enough

* rtic-macros: syn2 changed some error messages

Additionally some spans were not retained
with the manual parsing workaround

* rtic-macros: clippy fixes

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Henrik Tjäder <henrik@tjaders.com>

1 files changed, 23 insertions, 30 deletions

diff --git a/rtic-macros/src/syntax/parse.rs b/rtic-macros/src/syntax/parse.rs
index 823bd82..aae8a50 100644
--- a/rtic-macros/src/syntax/parse.rs
+++ b/rtic-macros/src/syntax/parse.rs
@@ -8,7 +8,7 @@ mod util;
 
 use proc_macro2::TokenStream as TokenStream2;
 use syn::{
-    braced, parenthesized,
+    braced,
     parse::{self, Parse, ParseStream, Parser},
     token::Brace,
     Ident, Item, LitInt, Token,
@@ -70,15 +70,12 @@ fn init_args(tokens: TokenStream2) -> parse::Result<InitArgs> {
 
         let mut local_resources = None;
 
-        let content;
-        parenthesized!(content in input);
-
-        if !content.is_empty() {
+        if !input.is_empty() {
             loop {
                 // Parse identifier name
-                let ident: Ident = content.parse()?;
+                let ident: Ident = input.parse()?;
                 // Handle equal sign
-                let _: Token![=] = content.parse()?;
+                let _: Token![=] = input.parse()?;
 
                 match &*ident.to_string() {
                     "local" => {
@@ -89,18 +86,18 @@ fn init_args(tokens: TokenStream2) -> parse::Result<InitArgs> {
                             ));
                         }
 
-                        local_resources = Some(util::parse_local_resources(&content)?);
+                        local_resources = Some(util::parse_local_resources(input)?);
                     }
                     _ => {
                         return Err(parse::Error::new(ident.span(), "unexpected argument"));
                     }
                 }
 
-                if content.is_empty() {
+                if input.is_empty() {
                     break;
                 }
                 // Handle comma: ,
-                let _: Token![,] = content.parse()?;
+                let _: Token![,] = input.parse()?;
             }
         }
 
@@ -131,14 +128,12 @@ fn idle_args(tokens: TokenStream2) -> parse::Result<IdleArgs> {
         let mut shared_resources = None;
         let mut local_resources = None;
 
-        let content;
-        parenthesized!(content in input);
-        if !content.is_empty() {
+        if !input.is_empty() {
             loop {
                 // Parse identifier name
-                let ident: Ident = content.parse()?;
+                let ident: Ident = input.parse()?;
                 // Handle equal sign
-                let _: Token![=] = content.parse()?;
+                let _: Token![=] = input.parse()?;
 
                 match &*ident.to_string() {
                     "shared" => {
@@ -149,7 +144,7 @@ fn idle_args(tokens: TokenStream2) -> parse::Result<IdleArgs> {
                             ));
                         }
 
-                        shared_resources = Some(util::parse_shared_resources(&content)?);
+                        shared_resources = Some(util::parse_shared_resources(input)?);
                     }
 
                     "local" => {
@@ -160,19 +155,19 @@ fn idle_args(tokens: TokenStream2) -> parse::Result<IdleArgs> {
                             ));
                         }
 
-                        local_resources = Some(util::parse_local_resources(&content)?);
+                        local_resources = Some(util::parse_local_resources(input)?);
                     }
 
                     _ => {
                         return Err(parse::Error::new(ident.span(), "unexpected argument"));
                     }
                 }
-                if content.is_empty() {
+                if input.is_empty() {
                     break;
                 }
 
                 // Handle comma: ,
-                let _: Token![,] = content.parse()?;
+                let _: Token![,] = input.parse()?;
             }
         }
 
@@ -196,19 +191,17 @@ fn task_args(tokens: TokenStream2) -> parse::Result<Either<HardwareTaskArgs, Sof
         let mut local_resources = None;
         let mut prio_span = None;
 
-        let content;
-        parenthesized!(content in input);
         loop {
-            if content.is_empty() {
+            if input.is_empty() {
                 break;
             }
 
             // Parse identifier name
-            let ident: Ident = content.parse()?;
+            let ident: Ident = input.parse()?;
             let ident_s = ident.to_string();
 
             // Handle equal sign
-            let _: Token![=] = content.parse()?;
+            let _: Token![=] = input.parse()?;
 
             match &*ident_s {
                 "binds" => {
@@ -220,7 +213,7 @@ fn task_args(tokens: TokenStream2) -> parse::Result<Either<HardwareTaskArgs, Sof
                     }
 
                     // Parse identifier name
-                    let ident = content.parse()?;
+                    let ident = input.parse()?;
 
                     binds = Some(ident);
                 }
@@ -234,7 +227,7 @@ fn task_args(tokens: TokenStream2) -> parse::Result<Either<HardwareTaskArgs, Sof
                     }
 
                     // #lit
-                    let lit: LitInt = content.parse()?;
+                    let lit: LitInt = input.parse()?;
 
                     if !lit.suffix().is_empty() {
                         return Err(parse::Error::new(
@@ -263,7 +256,7 @@ fn task_args(tokens: TokenStream2) -> parse::Result<Either<HardwareTaskArgs, Sof
                         ));
                     }
 
-                    shared_resources = Some(util::parse_shared_resources(&content)?);
+                    shared_resources = Some(util::parse_shared_resources(input)?);
                 }
 
                 "local" => {
@@ -274,7 +267,7 @@ fn task_args(tokens: TokenStream2) -> parse::Result<Either<HardwareTaskArgs, Sof
                         ));
                     }
 
-                    local_resources = Some(util::parse_local_resources(&content)?);
+                    local_resources = Some(util::parse_local_resources(input)?);
                 }
 
                 _ => {
@@ -282,12 +275,12 @@ fn task_args(tokens: TokenStream2) -> parse::Result<Either<HardwareTaskArgs, Sof
                 }
             }
 
-            if content.is_empty() {
+            if input.is_empty() {
                 break;
             }
 
             // Handle comma: ,
-            let _: Token![,] = content.parse()?;
+            let _: Token![,] = input.parse()?;
         }
         let shared_resources = shared_resources.unwrap_or_default();
         let local_resources = local_resources.unwrap_or_default();