1 files changed, 65 insertions, 0 deletions
diff --git a/engine-macros/src/util.rs b/engine-macros/src/util.rs
new file mode 100644
index 0000000..515b066
--- /dev/null
+++ b/engine-macros/src/util.rs
@@ -0,0 +1,65 @@
+use std::fmt::Write;
+
+use quote::ToTokens;
+
+macro_rules! syn_path {
+    ($first_segment: ident $(::$segment: ident)*) => {
+        ::syn::Path {
+            leading_colon: None,
+            segments: ::syn::punctuated::Punctuated::from_iter([
+                syn_path_segment!($first_segment),
+                $(syn_path_segment!($segment),)*
+            ])
+        }
+    };
+}
+
+macro_rules! syn_path_segment {
+    ($segment: ident) => {
+        ::syn::PathSegment {
+            ident: ::proc_macro2::Ident::new(
+                stringify!($segment),
+                ::proc_macro2::Span::call_site(),
+            ),
+            arguments: ::syn::PathArguments::None,
+        }
+    };
+}
+
+pub fn find_engine_crate_path() -> Option<syn::Path>
+{
+    let cargo_crate_name = std::env::var("CARGO_CRATE_NAME").ok()?;
+    let cargo_pkg_name = std::env::var("CARGO_PKG_NAME").ok()?;
+
+    if cargo_pkg_name == "engine" && cargo_crate_name != "engine" {
+        // Macro is used by a crate example/test/benchmark
+        return Some(syn_path!(engine));
+    }
+
+    if cargo_crate_name == "engine" {
+        return Some(syn_path!(crate));
+    }
+
+    Some(syn_path!(engine))
+}
+
+pub fn syn_path_to_string(path: &syn::Path) -> String
+{
+    let mut output = String::with_capacity(2 + path.segments.len() * 8);
+
+    if let Some(leading_colon) = path.leading_colon {
+        write!(output, "{}", leading_colon.to_token_stream()).unwrap();
+    }
+
+    for (segment, punct) in path.segments.pairs().map(syn::punctuated::Pair::into_tuple) {
+        let segment_ident = &segment.ident;
+
+        write!(output, "{segment_ident}",).unwrap();
+
+        if let Some(punct) = punct {
+            write!(output, "{}", punct.to_token_stream()).unwrap();
+        }
+    }
+
+    output
+}