Skip to content

refactor(macros): bump syn to v3 #679

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
AudaciousAxiom wants to merge 2 commits into
base: master
Choose a base branch
from
+4 −4
Open

refactor(macros): bump syn to v3 #679

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
c5dc35f
refactor(cortex-m-rt-macros): bump `syn` to v3
AudaciousAxiom Aug 5, 2026
3ed9ea5
chore(cortex-m-macros): allow `syn` v3
AudaciousAxiom Aug 5, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 1 addition & 1 deletion cortex-m-rt/macros/Cargo.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,4 +19,4 @@ proc-macro2 = "1.0"

[dependencies.syn]
features = ["extra-traits", "full"]
version = "2.0"
version = "3.0"
4 changes: 2 additions & 2 deletions cortex-m-rt/macros/src/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -240,7 +240,7 @@ pub fn exception(args: TokenStream, input: TokenStream) -> TokenStream {
}
};

if f.sig.unsafety.is_none() {
if !matches!(f.sig.safety, syn::Safety::Unsafe(_)) {

@AudaciousAxiom AudaciousAxiom Aug 5, 2026

Copy link
Copy Markdown
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Function "safety" is now encoded with a 3-variant enum.

@AudaciousAxiom AudaciousAxiom Aug 5, 2026

Copy link
Copy Markdown
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Function "safety" is now encoded with a 3-variant enum.

match exn {
Exception::DefaultHandler | Exception::HardFault(_) | Exception::NonMaskableInt => {
// These are unsafe to define.
Expand Down Expand Up @@ -635,7 +635,7 @@ pub fn pre_init(args: TokenStream, input: TokenStream) -> TokenStream {
// check the function signature
let valid_signature = f.sig.constness.is_none()
&& f.vis == Visibility::Inherited
&& f.sig.unsafety.is_some()
&& matches!(f.sig.safety, syn::Safety::Unsafe(_))
&& f.sig.abi.is_none()
&& f.sig.inputs.is_empty()
&& f.sig.generics.params.is_empty()
Expand Down
2 changes: 1 addition & 1 deletion cortex-m/macros/Cargo.toml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@ proc-macro = true
[dependencies]
proc-macro2 = "1.0.106"
quote = "1.0.45"
syn = { version = "2.0.117", features = ["extra-traits", "full"] }
syn = { version = ">= 2.0.117, < 4", features = ["extra-traits", "full"] }

@AudaciousAxiom AudaciousAxiom Aug 5, 2026

Copy link
Copy Markdown
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

cortex-m-macros seems to work with either syn v2 or v3: this allows both but, because cortex-m-rt-macros does depend on the v3 specifically, and as most dependents use both, you may prefer to depend on the v3 to simplify this a bit:

Suggested change
syn = { version = ">= 2.0.117, < 4", features = ["extra-traits", "full"] }
syn = { version = "3.0", features = ["extra-traits", "full"] }

Allowing both versions allows dependents that only depend on cortex-m-macros and don't otherwise have a (transitive) dependency on syn v3 to only use syn v2, thus avoiding the dependency duplication.


[dev-dependencies]
macrotest = "1.2.1"
Expand Down