Trans - Only codegen drop impls if needed

2 files changed, 8 insertions, 1 deletions

diff --git a/src/hir/path.hpp b/src/hir/path.hpp
index 7734b657..addfba05 100644
--- a/src/hir/path.hpp
+++ b/src/hir/path.hpp
@@ -110,6 +110,12 @@ struct PathParams
     Compare compare_with_placeholders(const Span& sp, const PathParams& x, t_cb_resolve_type resolve_placeholder) const;
     Compare match_test_generics_fuzz(const Span& sp, const PathParams& x, t_cb_resolve_type resolve_placeholder, t_cb_match_generics) const;
 
+    /// Indicates that params exist (and thus the target requires monomorphisation)
+    /// - Ignores lifetime params
+    bool has_params() const {
+        return !m_types.empty();
+    }
+
     bool operator==(const PathParams& x) const;
     bool operator!=(const PathParams& x) const { return !(*this == x); }
     bool operator<(const PathParams& x) const { return ord(x) == OrdLess; }
diff --git a/src/trans/enumerate.cpp b/src/trans/enumerate.cpp
index 54bf4ed7..283617f2 100644
--- a/src/trans/enumerate.cpp
+++ b/src/trans/enumerate.cpp
@@ -1035,7 +1035,8 @@ void Trans_Enumerate_Types(EnumState& state)
                 )
                 ASSERT_BUG(Span(), markings_ptr, "Path binding not set correctly - " << ty);
 
-                if( markings_ptr->has_drop_impl )
+                // If the type has a drop impl, and it's either defined in this crate or has params (and thus was monomorphised)
+                if( markings_ptr->has_drop_impl && (te.path.m_data.as_Generic().m_path.m_crate_name == state.crate.m_crate_name || te.path.m_data.as_Generic().m_params.has_params()) )
                 {
                     // Add the Drop impl to the codegen list
                     Trans_Enumerate_FillFrom_Path(state,  ::HIR::Path( ty.clone(), state.crate.get_lang_item_path(sp, "drop"), "drop"), {});