feat: add internal logging for macros

5 files changed, 123 insertions, 0 deletions

diff --git a/macros/Cargo.toml b/macros/Cargo.toml
index ccf10cd..4764221 100644
--- a/macros/Cargo.toml
+++ b/macros/Cargo.toml
@@ -30,6 +30,10 @@ once_cell = "1.13.1"
 thiserror = "1.0.37"
 proc-macro-error = "1.0.4"
 
+[target.'cfg(syrette_macros_logging)'.dependencies]
+tracing = "0.1.37"
+tracing-subscriber = "0.3.17"
+
 [dev_dependencies]
 syrette = { version = "0.4.2", path = ".." }
 mockall = "0.11.4"
diff --git a/macros/src/caster.rs b/macros/src/caster.rs
index c36aa1f..417a881 100644
--- a/macros/src/caster.rs
+++ b/macros/src/caster.rs
@@ -18,16 +18,27 @@ use quote::{format_ident, quote, ToTokens};
 use uuid::adapter::Simple;
 use uuid::Uuid;
 
+#[cfg(syrette_macros_logging)]
+use crate::util::tokens::ToTokensExt;
+
 const CASTER_FN_NAME_PREFIX: &[u8] = b"__";
 
 const FN_BUF_LEN: usize = CASTER_FN_NAME_PREFIX.len() + Simple::LENGTH;
 
+#[cfg_attr(syrette_macros_logging, tracing::instrument(skip(ty, dst_trait)))]
 pub fn generate_caster(
     ty: &impl ToTokens,
     dst_trait: &impl ToTokens,
     sync: bool,
 ) -> TokenStream
 {
+    #[cfg(syrette_macros_logging)]
+    tracing::debug!(
+        source = %ty.to_str_pretty(),
+        destination = %ty.to_str_pretty(),
+        "Generating caster",
+    );
+
     let fn_ident = create_caster_fn_ident(Uuid::new_v4());
 
     let new_caster = if sync {
diff --git a/macros/src/lib.rs b/macros/src/lib.rs
index 2fc3c21..41001ae 100644
--- a/macros/src/lib.rs
+++ b/macros/src/lib.rs
@@ -482,6 +482,9 @@ pub fn declare_interface(input: TokenStream) -> TokenStream
         .map_or_else(|| Ok(false), MacroFlag::get_bool)
         .unwrap_or_abort();
 
+    #[cfg(syrette_macros_logging)]
+    init_logging();
+
     let interface_type = if interface == implementation {
         Type::Path(interface)
     } else {
@@ -545,3 +548,18 @@ pub fn named(_: TokenStream, _: TokenStream) -> TokenStream
 {
     TokenStream::new()
 }
+
+#[cfg(syrette_macros_logging)]
+fn init_logging()
+{
+    use tracing::Level;
+    use tracing_subscriber::FmtSubscriber;
+
+    let subscriber = FmtSubscriber::builder()
+        .with_max_level(Level::DEBUG)
+        .finish();
+
+    // The error can be ignored because it doesn't matter if the global default
+    // has already been set
+    tracing::subscriber::set_global_default(subscriber).ok();
+}
diff --git a/macros/src/util/mod.rs b/macros/src/util/mod.rs
index d3edb67..2244229 100644
--- a/macros/src/util/mod.rs
+++ b/macros/src/util/mod.rs
@@ -3,6 +3,7 @@ pub mod item_impl;
 pub mod iterator_ext;
 pub mod string;
 pub mod syn_path;
+pub mod tokens;
 
 macro_rules! to_option {
     ($($tokens: tt)+) => {
diff --git a/macros/src/util/tokens.rs b/macros/src/util/tokens.rs
new file mode 100644
index 0000000..c614ea0
--- /dev/null
+++ b/macros/src/util/tokens.rs
@@ -0,0 +1,89 @@
+use std::fmt::Write;
+
+use proc_macro2::{Delimiter, Spacing, TokenTree};
+use quote::ToTokens;
+
+pub trait ToTokensExt
+{
+    fn to_str_pretty(&self) -> String;
+}
+
+impl<T: ToTokens> ToTokensExt for T
+{
+    fn to_str_pretty(&self) -> String
+    {
+        let mut spaceable = Spaceable::None;
+
+        self.to_token_stream()
+            .into_iter()
+            .fold(String::new(), |mut acc, token_tree| {
+                let prev_spaceable = spaceable;
+
+                spaceable = get_tt_spaceable(&token_tree);
+
+                if matches!(prev_spaceable, Spaceable::Left | Spaceable::LeftRight)
+                    && matches!(spaceable, Spaceable::Right | Spaceable::LeftRight)
+                {
+                    write!(acc, " ").ok();
+                }
+
+                match token_tree {
+                    TokenTree::Group(group) => match group.delimiter() {
+                        Delimiter::Parenthesis => {
+                            write!(acc, "({})", group.stream().to_str_pretty()).ok();
+                        }
+                        Delimiter::Brace => {
+                            write!(acc, "{{{}}}", group.stream().to_str_pretty()).ok();
+                        }
+                        Delimiter::Bracket => {
+                            write!(acc, "[{}]", group.stream().to_str_pretty()).ok();
+                        }
+                        Delimiter::None => {
+                            write!(acc, "{}", group.stream().to_str_pretty()).ok();
+                        }
+                    },
+                    tt => {
+                        write!(acc, "{tt}").ok();
+                    }
+                }
+
+                acc
+            })
+    }
+}
+
+fn get_tt_spaceable(token_tree: &TokenTree) -> Spaceable
+{
+    match &token_tree {
+        TokenTree::Ident(_) => Spaceable::LeftRight,
+        TokenTree::Punct(punct)
+            if punct.spacing() == Spacing::Alone && (punct.as_char() == '+') =>
+        {
+            Spaceable::LeftRight
+        }
+        TokenTree::Punct(punct)
+            if punct.spacing() == Spacing::Alone
+                && (punct.as_char() == '>' || punct.as_char() == ',') =>
+        {
+            Spaceable::Left
+        }
+        TokenTree::Punct(punct)
+            if punct.spacing() == Spacing::Joint && punct.as_char() == '-' =>
+        {
+            // Is part of ->
+            Spaceable::Right
+        }
+        TokenTree::Punct(punct) if punct.as_char() == '&' => Spaceable::Right,
+        TokenTree::Group(_) => Spaceable::Left,
+        _ => Spaceable::None,
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+enum Spaceable
+{
+    Left,
+    Right,
+    LeftRight,
+    None,
+}