HIR Typecheck Expr - Draft auto trait impl search

3 files changed, 66 insertions, 1 deletions

diff --git a/src/hir/hir.cpp b/src/hir/hir.cpp
index aa3344eb..40ad9f86 100644
--- a/src/hir/hir.cpp
+++ b/src/hir/hir.cpp
@@ -560,6 +560,26 @@ bool ::HIR::Crate::find_trait_impls(const ::HIR::SimplePath& trait, const ::HIR:
     }
     return false;
 }
+bool ::HIR::Crate::find_auto_trait_impls(const ::HIR::SimplePath& trait, const ::HIR::TypeRef& type, t_cb_resolve_type ty_res, ::std::function<bool(const ::HIR::MarkerImpl&)> callback) const
+{
+    auto its = this->m_marker_impls.equal_range( trait );
+    for( auto it = its.first; it != its.second; ++ it )
+    {
+        const auto& impl = it->second;
+        if( impl.matches_type(type, ty_res) ) {
+            if( callback(impl) ) {
+                return true;
+            }
+        }
+    }
+    for( const auto& ec : this->m_ext_crates )
+    {
+        if( ec.second->find_auto_trait_impls(trait, type, ty_res, callback) ) {
+            return true;
+        }
+    }
+    return false;
+}
 bool ::HIR::Crate::find_type_impls(const ::HIR::TypeRef& type, t_cb_resolve_type ty_res, ::std::function<bool(const ::HIR::TypeImpl&)> callback) const
 {
     for( const auto& impl : this->m_type_impls )
diff --git a/src/hir/hir.hpp b/src/hir/hir.hpp
index e1406067..c439960a 100644
--- a/src/hir/hir.hpp
+++ b/src/hir/hir.hpp
@@ -190,7 +190,7 @@ struct Trait
     ::std::string   m_lifetime;
     ::std::vector< ::HIR::TraitPath >  m_parent_traits;
     
-    bool    m_is_marker;
+    bool    m_is_marker;    // aka OIBIT
     
     ::std::unordered_map< ::std::string, AssociatedType >   m_types;
     ::std::unordered_map< ::std::string, TraitValueItem >   m_values;
@@ -361,6 +361,7 @@ public:
     }
     
     bool find_trait_impls(const ::HIR::SimplePath& path, const ::HIR::TypeRef& type, t_cb_resolve_type ty_res, ::std::function<bool(const ::HIR::TraitImpl&)> callback) const;
+    bool find_auto_trait_impls(const ::HIR::SimplePath& path, const ::HIR::TypeRef& type, t_cb_resolve_type ty_res, ::std::function<bool(const ::HIR::MarkerImpl&)> callback) const;
     bool find_type_impls(const ::HIR::TypeRef& type, t_cb_resolve_type ty_res, ::std::function<bool(const ::HIR::TypeImpl&)> callback) const;
 };
 
diff --git a/src/hir_typeck/helpers.cpp b/src/hir_typeck/helpers.cpp
index e9276601..14c6085f 100644
--- a/src/hir_typeck/helpers.cpp
+++ b/src/hir_typeck/helpers.cpp
@@ -1881,6 +1881,50 @@ bool TraitResolution::find_trait_impls_crate(const Span& sp,
 {
     TRACE_FUNCTION_F(trait << FMT_CB(ss, if(params_ptr) { ss << *params_ptr; } else { ss << "<?>"; }) << " for " << type);
     
+    // Handle auto traits (aka OIBITs)
+    if( m_crate.get_trait_by_path(sp, trait).m_is_marker )
+    {
+        // NOTE: Expected behavior is for Ivars to return false
+        // TODO: Should they return Compare::Fuzzy instead?
+        if( type.m_data.is_Infer() ) {
+            return false;
+        }
+        
+        // - Search for positive impls for this type
+        bool positive_found = this->m_crate.find_auto_trait_impls(trait, type, this->m_ivars.callback_resolve_infer(),
+            [&](const auto& impl) {
+                // Skip any negative impls on this pass
+                if( impl.is_positive != true )
+                    return false;
+                TODO(sp, "Matching positive impl " << trait << " for " << type);
+            });
+        if( positive_found ) {
+            // A positive impl was found, so return true (callback should have been called)
+            return true;
+        }
+        
+        // - Search for negative impls for this type
+        bool negative_found = this->m_crate.find_auto_trait_impls(trait, type, this->m_ivars.callback_resolve_infer(),
+            [&](const auto& impl) {
+                // Skip any positive impls
+                if( impl.is_positive != false )
+                    return false;
+                TODO(sp, "Matching negative impl !" << trait << " for " << type);
+            });
+        if( negative_found ) {
+            // A negative impl _was_ found, so return false
+            return false;
+        }
+        
+        // - If the type is a path (struct/enum/...), search for impls for all contained types.
+        TU_IFLET( ::HIR::TypeRef::Data, type.m_data, Path, e,
+        )
+        // Otherwise, there's no negative so it must be positive
+        else {
+            return true;
+        }
+    }
+    
     return this->m_crate.find_trait_impls(trait, type, this->m_ivars.callback_resolve_infer(),
         [&](const auto& impl) {
             DEBUG("[find_trait_impls_crate] Found impl" << impl.m_params.fmt_args() << " " << trait << impl.m_trait_args << " for " << impl.m_type << " " << impl.m_params.fmt_bounds());