Changeset b95fe40 for src/GenPoly/InstantiateGeneric.cc

Timestamp:

Nov 22, 2017, 3:40:12 PM (6 years ago)

Author:

Rob Schluntz <rschlunt@…>

Branches:

ADT, aaron-thesis, arm-eh, ast-experimental, cleanup-dtors, deferred_resn, demangler, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, pthread-emulation, qualifiedEnum, resolv-new, with_gc

Children:

7e4c4f4

Parents:

98a249fb

Message:

Add casts to dtype-static member expressions to prevent loss of type information [fixes #42] [fixes #59]

File:

• src/GenPoly/InstantiateGeneric.cc (modified) (4 diffs)

src/GenPoly/InstantiateGeneric.cc

@@ -27 +27 @@
 #include "Common/utility.h"            // for deleteAll, cloneAll
 #include "GenPoly.h"                   // for isPolyType, typesPolyCompatible
+#include "ResolvExpr/typeops.h"
 #include "ScopedSet.h"                 // for ScopedSet, ScopedSet<>::iterator
 #include "ScrubTyVars.h"               // for ScrubTyVars
@@ -151 +152 @@
                 return gt;
         }
+
+        /// Add cast to dtype-static member expressions so that type information is not lost in GenericInstantiator
+        struct FixDtypeStatic final {
+                Expression * postmutate( MemberExpr * memberExpr );
+
+                template<typename AggrInst>
+                Expression * fixMemberExpr( AggrInst * inst, MemberExpr * memberExpr );
+        };
 
         /// Mutator pass that replaces concrete instantiations of generic types with actual struct declarations, scoped appropriately
@@ -198 +207 @@
 
         void instantiateGeneric( std::list< Declaration* > &translationUnit ) {
+                PassVisitor<FixDtypeStatic> fixer;
                 PassVisitor<GenericInstantiator> instantiator;
+
+                mutateAll( translationUnit, fixer );
                 mutateAll( translationUnit, instantiator );
+        }
+
+        bool isDtypeStatic( const std::list< TypeDecl* >& baseParams ) {
+                return std::all_of( baseParams.begin(), baseParams.end(), []( TypeDecl * td ) { return ! td->isComplete(); } );
         }
 
@@ -479 +495 @@
         }
 
+        template< typename AggrInst >
+        Expression * FixDtypeStatic::fixMemberExpr( AggrInst * inst, MemberExpr * memberExpr ) {
+                // need to cast dtype-static member expressions to their actual type before that type is erased.
+                auto & baseParams = *inst->get_baseParameters();
+                if ( isDtypeStatic( baseParams ) ) {
+                        if ( ! ResolvExpr::typesCompatible( memberExpr->result, memberExpr->member->get_type(), SymTab::Indexer() ) ) {
+                                // type of member and type of expression differ, so add cast to actual type
+                                return new CastExpr( memberExpr, memberExpr->result->clone() );
+                        }
+                }
+                return memberExpr;
+        }
+
+        Expression * FixDtypeStatic::postmutate( MemberExpr * memberExpr ) {
+                Type * aggrType = memberExpr->aggregate->result;
+                if ( isGenericType( aggrType ) ) {
+                        if ( StructInstType * inst = dynamic_cast< StructInstType * >( aggrType ) ) {
+                                return fixMemberExpr( inst, memberExpr );
+                        } else if ( UnionInstType * inst = dynamic_cast< UnionInstType * >( aggrType ) ) {
+                                return fixMemberExpr( inst, memberExpr );
+                        }
+                }
+                return memberExpr;
+        }
+
 } // namespace GenPoly