Changeset e6cee92 for src/ResolvExpr

Timestamp:

Jul 17, 2017, 3:25:58 PM (7 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:

795d450

Parents:

7ebaa56

Message:

Fix TupleAssignment? code for references

Location:

src/ResolvExpr

Files:

• AlternativeFinder.cc (modified) (1 diff)
• CommonType.cc (modified) (1 diff)
• Unify.cc (modified) (1 diff)

src/ResolvExpr/AlternativeFinder.cc

@@ -815 +815 @@
 
         Expression * restructureCast( Expression * argExpr, Type * toType ) {
-                if ( argExpr->get_result()->size() > 1 && ! toType->isVoid() ) {
-                        // Argument expression is a tuple and the target type is not void. Cast each member of the tuple
-                        // to its corresponding target type, producing the tuple of those cast expressions. If there are
-                        // more components of the tuple than components in the target type, then excess components do not
-                        // come out in the result expression (but UniqueExprs ensure that side effects will still be done).
+                if ( argExpr->get_result()->size() > 1 && ! toType->isVoid() && ! dynamic_cast<ReferenceType *>( toType ) ) {
+                        // Argument expression is a tuple and the target type is not void and not a reference type.
+                        // Cast each member of the tuple to its corresponding target type, producing the tuple of those
+                        // cast expressions. If there are more components of the tuple than components in the target type,
+                        // then excess components do not come out in the result expression (but UniqueExprs ensure that
+                        // side effects will still be done).
                         if ( Tuples::maybeImpure( argExpr ) && ! dynamic_cast< UniqueExpr * >( argExpr ) ) {
                                 // expressions which may contain side effects require a single unique instance of the expression.

src/ResolvExpr/CommonType.cc

@@ -81 +81 @@
                 CommonType visitor( type2, widenFirst, widenSecond, indexer, env, openVars );
 
-                ReferenceType * refType1 = dynamic_cast< ReferenceType * >( type1 );
-                ReferenceType * refType2 = dynamic_cast< ReferenceType * >( type2 );
-                if ( (refType1 || refType2) && (! refType1 || ! refType2) ) {
-                        // handle the case where exactly one of the types is a reference type specially
-                        if ( refType1 ) {
-                                return handleReference( refType1, type2, widenFirst, widenSecond, indexer, env, openVars );
-                        } else if ( refType2 ) {
-                                return handleReference( refType2, type1, widenSecond, widenFirst, indexer, env, openVars );
-                        }
+                int depth1 = type1->referenceDepth();
+                int depth2 = type2->referenceDepth();
+                if ( depth1 > 0 || depth2 > 0 ) {
+                        int diff = depth1-depth2;
+                        // TODO: should it be possible for commonType to generate complicated conversions? I would argue no, only conversions that involve types of the same reference level or a difference of 1 should be allowed.
+                        if ( diff > 1 || diff < -1 ) return nullptr;
+
+                        // special case where one type has a reference depth of 1 larger than the other
+                        if ( diff > 0 ) {
+                                return handleReference( safe_dynamic_cast<ReferenceType *>( type1 ), type2, widenFirst, widenSecond, indexer, env, openVars );
+                        } else if ( diff < 0 ) {
+                                return handleReference( safe_dynamic_cast<ReferenceType *>( type2 ), type1, widenSecond, widenFirst, indexer, env, openVars );
+                        }
+                        // otherwise, both are reference types of the same depth and this is handled by the CommonType visitor.
                 }
 

src/ResolvExpr/Unify.cc

@@ -377 +377 @@
                                 } // if
                         } else {
+                                common = type1->clone();
+                                common->get_qualifiers() = tq1 | tq2;
                                 result = true;
                         } // if