1 files changed, 41 insertions, 0 deletions
diff --git a/src/errors/merge_error.rs b/src/errors/merge_error.rs
new file mode 100644
index 0000000..a694b71
--- /dev/null
+++ b/src/errors/merge_error.rs
@@ -0,0 +1,41 @@
+use crate::*;
+
+use ansi::*;
+use log::error;
+
+
+pub struct MergeError<'a> {
+    pub resolver: &'a Resolver,
+    /// A list of source units involved in a cycle.
+    pub cyclic_unit_ids: Vec<usize>,
+}
+
+impl MergeError<'_> {
+    pub fn report(&self) {
+        error!("A cyclic dependency was found between the following libraries:");
+        for id in &self.cyclic_unit_ids {
+            if let Some(unit) = self.resolver.source_units.get(*id) {
+                let path = &unit.source_unit.path();
+                match unit.source_unit.name() {
+                    Some(name) =>
+                        eprintln!("{name}{NORMAL}{DIM} ({path}){NORMAL}"),
+                    None =>
+                        eprintln!("{path}"),
+                };
+                // Print each parent involved in the dependency cycle.
+                for parent_id in &unit.parent_ids {
+                    if !self.cyclic_unit_ids.contains(parent_id) { continue; }
+                    if let Some(parent_unit) = self.resolver.source_units.get(*parent_id) {
+                        let parent_path = &parent_unit.source_unit.path();
+                        match parent_unit.source_unit.name() {
+                            Some(parent_name) =>
+                                eprintln!("  => {parent_name} {DIM}({parent_path}){NORMAL}"),
+                            None =>
+                                eprintln!("  => {parent_path}"),
+                        };
+                    }
+                }
+            }
+        }
+    }
+}