Changeset 0a60c04

Timestamp:

Dec 4, 2017, 3:37:28 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:

866f560

Parents:

ac57659

Message:

Introduce a temporary for with expressions that may contain side-effects and evaluate the expression once

File:

• src/ResolvExpr/Resolver.cc (modified) (4 diffs)

src/ResolvExpr/Resolver.cc

@@ -26 +26 @@
 #include "Common/utility.h"              // for ValueGuard, group_iterate
 #include "CurrentObject.h"               // for CurrentObject
+#include "InitTweak/GenInit.h"
 #include "InitTweak/InitTweak.h"         // for isIntrinsicSingleArgCallStmt
 #include "RenameVars.h"                  // for RenameVars, global_renamer
@@ -40 +41 @@
 #include "SynTree/TypeSubstitution.h"    // for TypeSubstitution
 #include "SynTree/Visitor.h"             // for acceptAll, maybeAccept
+#include "Tuples/Tuples.h"
 #include "typeops.h"                     // for extractResultType
 #include "Unify.h"                       // for unify
@@ -46 +48 @@
 
 namespace ResolvExpr {
-        struct Resolver final : public WithIndexer, public WithGuards, public WithVisitorRef<Resolver>, public WithShortCircuiting {
+        struct Resolver final : public WithIndexer, public WithGuards, public WithVisitorRef<Resolver>, public WithShortCircuiting, public WithStmtsToAdd {
                 Resolver() {}
                 Resolver( const SymTab::Indexer & other ) {
@@ -611 +613 @@
                         expr = alt.expr;
                         alt.expr = nullptr;
+
+                        // if with expression might be impure, create a temporary so that it is evaluated once
+                        if ( Tuples::maybeImpure( expr ) ) {
+                                static UniqueName tmpNamer( "_with_tmp_" );
+                                ObjectDecl * tmp = ObjectDecl::newObject( tmpNamer.newName(), expr->result->clone(), new SingleInit( expr ) );
+                                expr = new VariableExpr( tmp );
+                                stmtsToAddBefore.push_back( new DeclStmt( tmp ) );
+                                if ( InitTweak::isConstructable( tmp->type ) ) {
+                                        // generate ctor/dtor and resolve them
+                                        tmp->init = InitTweak::genCtorInit( tmp );
+                                        tmp->accept( *visitor );
+                                }
+                        }
                 }
         }