Changeset 623ecf3 for src

Timestamp:

Mar 21, 2017, 3:26:09 PM (8 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:

597db97

Parents:

f5392c1

Message:

trim type environment for specialized expressions

File:

• src/GenPoly/Specialize.cc (modified) (2 diffs)

src/GenPoly/Specialize.cc

@@ -168 +168 @@
         }
 
+        struct EnvTrimmer : public Visitor {
+                TypeSubstitution * env, * newEnv;
+                EnvTrimmer( TypeSubstitution * env, TypeSubstitution * newEnv ) : env( env ), newEnv( newEnv ){}
+                virtual void visit( TypeDecl * tyDecl ) {
+                        // transfer known bindings for seen type variables
+                        if ( Type * t = env->lookup( tyDecl->get_name() ) ) {
+                                newEnv->add( tyDecl->get_name(), t );
+                        }
+                }
+        };
+
+        /// reduce environment to just the parts that are referenced in a given expression
+        TypeSubstitution * trimEnv( ApplicationExpr * expr, TypeSubstitution * env ) {
+                if ( env ) {
+                        TypeSubstitution * newEnv = new TypeSubstitution();
+                        EnvTrimmer trimmer( env, newEnv );
+                        expr->accept( trimmer );
+                        return newEnv;
+                }
+                return nullptr;
+        }
+
         /// Generates a thunk that calls `actual` with type `funType` and returns its address
         Expression * Specialize::createThunkFunction( FunctionType *funType, Expression *actual, InferredParams *inferParams ) {
@@ -211 +233 @@
                 }
 
-                appExpr->set_env( maybeClone( env ) );
+                appExpr->set_env( trimEnv( appExpr, env ) );
                 if ( inferParams ) {
                         appExpr->get_inferParams() = *inferParams;