From 1d81b59163fd5e43bc28248fd659940efdf70fd7 Mon Sep 17 00:00:00 2001
From: Andrey Tkachenko <a.tkachenko@kryptonite.ru>
Date: Tue, 28 Mar 2023 17:26:03 +0400
Subject: [PATCH] Derive derives on Error not ErrorKind

---
 Cargo.toml        |  6 +--
 derive/Cargo.toml |  4 +-
 derive/src/lib.rs | 94 +++++++++++++++++++++++++++--------------------
 3 files changed, 60 insertions(+), 44 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index bc4f466..dbce9c8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ctxerr"
-version = "0.2.0"
+version = "0.2.3"
 authors = ["Andrey Tkachenko <andrey@aidev.ru>"]
 repository = "https://github.com/andreytkachenko/ctxerr.git"
 keywords = ["error", "handling", "thiserror", "context", "backtrace"]
@@ -15,5 +15,5 @@ resolver = "2"
 members = ["derive"]
 
 [dependencies]
-ctxerr_derive = {version = "0.3.0", path = "derive"}
-thiserror = "1.0.39"
+ctxerr_derive = {version = "0.4.0", path = "derive"}
+thiserror = "1.0.40"
diff --git a/derive/Cargo.toml b/derive/Cargo.toml
index 0cc622e..078901f 100644
--- a/derive/Cargo.toml
+++ b/derive/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "ctxerr_derive"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Andrey Tkachenko <andrey@aidev.ru>"]
 repository = "https://github.com/andreytkachenko/ctxerr.git"
 keywords = ["error", "handling", "thiserror", "context", "backtrace"]
@@ -16,4 +16,4 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1"
 quote = "1"
-syn = {version = "1", features = ["full"]}
+syn = {version = "2", features = ["full"]}
diff --git a/derive/src/lib.rs b/derive/src/lib.rs
index 5b8757e..aeb1ab4 100644
--- a/derive/src/lib.rs
+++ b/derive/src/lib.rs
@@ -11,7 +11,7 @@ pub fn ctxerr(
     _metadata: proc_macro::TokenStream,
     input: proc_macro::TokenStream,
 ) -> proc_macro::TokenStream {
-    let ast: DeriveInput = syn::parse(input).unwrap();
+    let mut ast: DeriveInput = syn::parse(input).unwrap();
     let name = ast.ident.to_string();
     if !name.ends_with("Kind") {
         panic!("Ttypename should ends with `Kind`!");
@@ -19,53 +19,69 @@ pub fn ctxerr(
 
     let name_ident = &ast.ident;
     let base_name = Ident::new(&name[0..name.len() - 4], ast.ident.span());
+    let attrs = ast
+        .attrs
+        .drain(..)
+        .filter_map(|x| match x.meta {
+            syn::Meta::List(list) => Some(list.tokens),
+            _ => None,
+        })
+        .collect::<Vec<_>>();
+
     let tokens = quote! {
-        #[derive(Debug, ctxerr::thiserror::Error)]
-        #ast
+        pub use __private::*;
 
-        #[derive(ctxerr::thiserror::Error)]
-        pub struct #base_name {
-            kind: #name_ident,
-            backtrace: Option<std::backtrace::Backtrace>,
-            location: Option<&'static core::panic::Location<'static>>,
-        }
+        mod __private {
+            use super::*;
+            use ctxerr::thiserror;
 
-        impl std::fmt::Debug for #base_name {
-            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-                writeln!(f, "{:?}: {}", self.kind, self.kind)?;
-                if let Some(b) = &self.backtrace {
-                    writeln!(f, "backtrace: \n{}", b)?;
-                }
+            #[derive(Debug, ctxerr::thiserror::Error)]
+            #ast
 
-                Ok(())
+            #[derive(ctxerr::thiserror::Error #(, #attrs)*)]
+            pub struct #base_name {
+                kind: #name_ident,
+                backtrace: Option<std::backtrace::Backtrace>,
+                location: Option<&'static core::panic::Location<'static>>,
             }
-        }
 
-        impl std::fmt::Display for #base_name {
-            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-                write!(f, "{:?}: {}", self.kind, self.kind)?;
-                if let Some(loc) = self.location {
-                    writeln!(f, " file: {}:{}:{}", loc.file(), loc.line(), loc.column())?;
-                } else {
-                    writeln!(f)?;
+            impl std::fmt::Debug for #base_name {
+                fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                    writeln!(f, "{:?}: {}", self.kind, self.kind)?;
+                    if let Some(b) = &self.backtrace {
+                        writeln!(f, "backtrace: \n{}", b)?;
+                    }
+
+                    Ok(())
                 }
-
-                if let Some(b) = &self.backtrace {
-                    writeln!(f, "backtrace: \n{}", b)?;
-                }
-
-                Ok(())
             }
-        }
 
-        impl<T: Into<ErrorKind>> From<T> for #base_name {
-            #[track_caller]
-            fn from(val: T) -> Self {
-                let b = std::backtrace::Backtrace::capture();
-                Self{
-                    kind: val.into(),
-                    backtrace: Some(std::backtrace::Backtrace::capture()),
-                    location: Some(core::panic::Location::caller()),
+            impl std::fmt::Display for #base_name {
+                fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                    write!(f, "{:?}: {}", self.kind, self.kind)?;
+                    if let Some(loc) = self.location {
+                        writeln!(f, " file: {}:{}:{}", loc.file(), loc.line(), loc.column())?;
+                    } else {
+                        writeln!(f)?;
+                    }
+
+                    if let Some(b) = &self.backtrace {
+                        writeln!(f, "backtrace: \n{}", b)?;
+                    }
+
+                    Ok(())
+                }
+            }
+
+            impl<T: Into<ErrorKind>> From<T> for #base_name {
+                #[track_caller]
+                fn from(val: T) -> Self {
+                    let b = std::backtrace::Backtrace::capture();
+                    Self{
+                        kind: val.into(),
+                        backtrace: Some(std::backtrace::Backtrace::capture()),
+                        location: Some(core::panic::Location::caller()),
+                    }
                 }
             }
         }