Changeset 83b52f1 for src

Timestamp:

Jul 24, 2019, 10:40:28 AM (6 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

77d2432, 96ac72c0

Parents:

6130304 (diff), 8fc15cf (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

Location:

src

Files:

• InitTweak/InitTweak.cc (modified) (2 diffs)
• InitTweak/InitTweak.h (modified) (2 diffs)
• ResolvExpr/Alternative.h (modified) (1 diff)
• ResolvExpr/FindOpenVars.cc (modified) (9 diffs)
• ResolvExpr/FindOpenVars.h (modified) (1 diff)
• ResolvExpr/Occurs.cc (modified) (3 diffs)
• ResolvExpr/ResolveAssertions.cc (modified) (1 diff)
• ResolvExpr/TypeEnvironment.cc (modified) (7 diffs)
• ResolvExpr/TypeEnvironment.h (modified) (9 diffs)
• ResolvExpr/typeops.h (modified) (2 diffs)
• SynTree/Type.cc (modified) (2 diffs)
• SynTree/Type.h (modified) (2 diffs)
• Tuples/TupleExpansion.cc (modified) (6 diffs)
• Tuples/Tuples.h (modified) (1 diff)

src/InitTweak/InitTweak.cc

@@ -9 +9 @@
 // Author           : Rob Schluntz
 // Created On       : Fri May 13 11:26:36 2016
-// Last Modified By : Aaron B. Moss
-// Last Modified On : Mon Jun 10 13:30:00 2019
-// Update Count     : 5
+// Last Modified By : Andrew Beach
+// Last Modified On : Fri Jun 19 14:34:00 2019
+// Update Count     : 6
 //
 
@@ -633 +633 @@
                         return nullptr;
                 }
+
+                DeclarationWithType * getFunctionCore( const Expression * expr ) {
+                        if ( const auto * appExpr = dynamic_cast< const ApplicationExpr * >( expr ) ) {
+                                return getCalledFunction( appExpr->function );
+                        } else if ( const auto * untyped = dynamic_cast< const UntypedExpr * >( expr ) ) {
+                                return getCalledFunction( untyped->function );
+                        }
+                        assertf( false, "getFunction with unknown expression: %s", toString( expr ).c_str() );
+                }
         }
 
         DeclarationWithType * getFunction( Expression * expr ) {
-                if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( expr ) ) {
-                        return getCalledFunction( appExpr->get_function() );
-                } else if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * > ( expr ) ) {
-                        return getCalledFunction( untyped->get_function() );
-                }
-                assertf( false, "getFunction received unknown expression: %s", toString( expr ).c_str() );
+                return getFunctionCore( expr );
+        }
+
+        const DeclarationWithType * getFunction( const Expression * expr ) {
+                return getFunctionCore( expr );
         }
 

src/InitTweak/InitTweak.h

@@ -9 +9 @@
 // Author           : Rob Schluntz
 // Created On       : Fri May 13 11:26:36 2016
-// Last Modified By : Aaron B. Moss
-// Last Modified On : Mon Jun 10 13:30:00 2019
-// Update Count     : 5
+// Last Modified By : Andrew Beach
+// Last Modified On : Fri Jul 19 14:18:00 2019
+// Update Count     : 6
 //
 
@@ -61 +61 @@
         /// returns the declaration of the function called by the expr (must be ApplicationExpr or UntypedExpr)
         DeclarationWithType * getFunction( Expression * expr );
+        const DeclarationWithType * getFunction( const Expression * expr );
         const ast::DeclWithType * getFunction( const ast::Expr * expr );
 

src/ResolvExpr/Alternative.h

@@ -29 +29 @@
         /// One assertion to resolve
         struct AssertionItem {
-                DeclarationWithType* decl;
+                const DeclarationWithType* decl;
                 AssertionSetValue info;
-                
+
                 AssertionItem() = default;
-                AssertionItem( DeclarationWithType* decl, const AssertionSetValue& info ) 
+                AssertionItem( const DeclarationWithType* decl, const AssertionSetValue& info )
                 : decl(decl), info(info) {}
                 AssertionItem( const AssertionSet::value_type& e ) : decl(e.first), info(e.second) {}

src/ResolvExpr/FindOpenVars.cc

@@ -9 +9 @@
 // Author           : Richard C. Bilson
 // Created On       : Sun May 17 09:42:48 2015
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Sun May 17 09:45:25 2015
-// Update Count     : 3
+// Last Modified By : Andrew
+// Last Modified On : Fri Jul 12 14:18:00 2019
+// Update Count     : 4
 //
 
@@ -29 +29 @@
                 FindOpenVars_old( OpenVarSet &openVars, OpenVarSet &closedVars, AssertionSet &needAssertions, AssertionSet &haveAssertions, bool firstIsOpen );
 
-                void previsit( PointerType * pointerType );
-                void previsit( ArrayType * arrayType );
-                void previsit( FunctionType * functionType );
-                void previsit( TupleType * tupleType );
+                void previsit( const PointerType * pointerType );
+                void previsit( const ArrayType * arrayType );
+                void previsit( const FunctionType * functionType );
+                void previsit( const TupleType * tupleType );
 
-                void common_action( Type *type );
+                void common_action( const Type *type );
 
                 OpenVarSet &openVars, &closedVars;
@@ -41 +41 @@
         };
 
-        void findOpenVars( Type *type, OpenVarSet &openVars, OpenVarSet &closedVars, AssertionSet &needAssertions, AssertionSet &haveAssertions, bool firstIsOpen ) {
+        void findOpenVars( const Type *type, OpenVarSet &openVars, OpenVarSet &closedVars, AssertionSet &needAssertions, AssertionSet &haveAssertions, bool firstIsOpen ) {
                 PassVisitor<FindOpenVars_old> finder( openVars, closedVars, needAssertions, haveAssertions, firstIsOpen );
                 type->accept( finder );
@@ -50 +50 @@
         }
 
-        void FindOpenVars_old::common_action( Type *type ) {
+        void FindOpenVars_old::common_action( const Type * type ) {
                 if ( nextIsOpen ) {
-                        for ( Type::ForallList::const_iterator i = type->get_forall().begin(); i != type->get_forall().end(); ++i ) {
+                        for ( Type::ForallList::const_iterator i = type->forall.begin(); i != type->forall.end(); ++i ) {
                                 openVars[ (*i)->get_name() ] = TypeDecl::Data{ (*i) };
                                 for ( std::list< DeclarationWithType* >::const_iterator assert = (*i)->get_assertions().begin(); assert != (*i)->get_assertions().end(); ++assert ) {
@@ -61 +61 @@
                         }
                 } else {
-                        for ( Type::ForallList::const_iterator i = type->get_forall().begin(); i != type->get_forall().end(); ++i ) {
+                        for ( Type::ForallList::const_iterator i = type->forall.begin(); i != type->forall.end(); ++i ) {
                                 closedVars[ (*i)->get_name() ] = TypeDecl::Data{ (*i) };
                                 for ( std::list< DeclarationWithType* >::const_iterator assert = (*i)->get_assertions().begin(); assert != (*i)->get_assertions().end(); ++assert ) {
@@ -78 +78 @@
         }
 
-        void FindOpenVars_old::previsit(PointerType *pointerType) {
+        void FindOpenVars_old::previsit(const PointerType * pointerType) {
                 common_action( pointerType );
         }
 
-        void FindOpenVars_old::previsit(ArrayType *arrayType) {
+        void FindOpenVars_old::previsit(const ArrayType * arrayType) {
                 common_action( arrayType );
         }
 
-        void FindOpenVars_old::previsit(FunctionType *functionType) {
+        void FindOpenVars_old::previsit(const FunctionType * functionType) {
                 common_action( functionType );
                 nextIsOpen = ! nextIsOpen;
@@ -92 +92 @@
         }
 
-        void FindOpenVars_old::previsit(TupleType *tupleType) {
+        void FindOpenVars_old::previsit(const TupleType * tupleType) {
                 common_action( tupleType );
         }
@@ -104 +104 @@
                         bool nextIsOpen;
 
-                        FindOpenVars_new( 
-                                ast::OpenVarSet & o, ast::OpenVarSet & c, ast::AssertionSet & n, 
+                        FindOpenVars_new(
+                                ast::OpenVarSet & o, ast::OpenVarSet & c, ast::AssertionSet & n,
                                 ast::AssertionSet & h, FirstMode firstIsOpen )
                         : open( o ), closed( c ), need( n ), have( h ), nextIsOpen( firstIsOpen ) {}
@@ -135 +135 @@
         }
 
-        void findOpenVars( 
-                        const ast::Type * type, ast::OpenVarSet & open, ast::OpenVarSet & closed, 
+        void findOpenVars(
+                        const ast::Type * type, ast::OpenVarSet & open, ast::OpenVarSet & closed,
                         ast::AssertionSet & need, ast::AssertionSet & have, FirstMode firstIsOpen ) {
                 ast::Pass< FindOpenVars_new > finder{ open, closed, need, have, firstIsOpen };

src/ResolvExpr/FindOpenVars.h

@@ -26 +26 @@
 namespace ResolvExpr {
         // Updates open and closed variables and their associated assertions
-        void findOpenVars( Type *type, OpenVarSet &openVars, OpenVarSet &closedVars, AssertionSet &needAssertions, AssertionSet &haveAssertions, bool firstIsOpen );
+        void findOpenVars( const Type *type, OpenVarSet &openVars, OpenVarSet &closedVars, AssertionSet &needAssertions, AssertionSet &haveAssertions, bool firstIsOpen );
 
         enum FirstMode { FirstClosed, FirstOpen };

src/ResolvExpr/Occurs.cc

@@ -24 +24 @@
         struct Occurs : public WithVisitorRef<Occurs> {
                 Occurs( std::string varName, const TypeEnvironment &env );
-                void previsit( TypeInstType * typeInst );
+                void previsit( const TypeInstType * typeInst );
 
                 bool result;
@@ -31 +31 @@
         };
 
-        bool occurs( Type *type, std::string varName, const TypeEnvironment &env ) {
+        bool occurs( const Type *type, const std::string & varName, const TypeEnvironment &env ) {
                 PassVisitor<Occurs> occur( varName, env );
                 type->accept( occur );
@@ -45 +45 @@
         }
 
-        void Occurs::previsit( TypeInstType * typeInst ) {
+        void Occurs::previsit( const TypeInstType * typeInst ) {
                 ///   std::cerr << "searching for vars: ";
 ///   std::copy( eqvVars.begin(), eqvVars.end(), std::ostream_iterator< std::string >( std::cerr, " " ) );

src/ResolvExpr/ResolveAssertions.cc

@@ -73 +73 @@
                 CandidateList matches;
 
-                DeferItem( DeclarationWithType* decl, const AssertionSetValue& info, CandidateList&& matches )
+                DeferItem( const DeclarationWithType* decl, const AssertionSetValue& info, CandidateList&& matches )
                 : decl(decl), info(info), matches(std::move(matches)) {}
 

src/ResolvExpr/TypeEnvironment.cc

@@ -9 +9 @@
 // Author           : Richard C. Bilson
 // Created On       : Sun May 17 12:19:47 2015
-// Last Modified By : Aaron B. Moss
-// Last Modified On : Mon Jun 18 11:58:00 2018
-// Update Count     : 4
+// Last Modified By : Andrew Beach
+// Last Modified On : Fri Jun 18 14:27:00 2019
+// Update Count     : 5
 //
 
@@ -315 +315 @@
         }
 
-        bool isFtype( Type *type ) {
-                if ( dynamic_cast< FunctionType* >( type ) ) {
+        bool isFtype( const Type * type ) {
+                if ( dynamic_cast< const FunctionType * >( type ) ) {
                         return true;
-                } else if ( TypeInstType *typeInst = dynamic_cast< TypeInstType* >( type ) ) {
+                } else if ( const TypeInstType *typeInst = dynamic_cast< const TypeInstType * >( type ) ) {
                         return typeInst->get_isFtype();
                 } // if
@@ -324 +324 @@
         }
 
-        bool tyVarCompatible( const TypeDecl::Data & data, Type *type ) {
+        bool tyVarCompatible( const TypeDecl::Data & data, const Type * type ) {
                 switch ( data.kind ) {
                   case TypeDecl::Dtype:
@@ -336 +336 @@
                   case TypeDecl::Ttype:
                         // ttype unifies with any tuple type
-                        return dynamic_cast< TupleType * >( type ) || Tuples::isTtype( type );
+                        return dynamic_cast< const TupleType * >( type ) || Tuples::isTtype( type );
                   default:
                         assertf(false, "Unhandled tyvar kind: %d", data.kind);
@@ -343 +343 @@
         }
 
-        bool TypeEnvironment::bindVar( TypeInstType *typeInst, Type *bindTo, const TypeDecl::Data & data, AssertionSet &need, AssertionSet &have, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
+        bool TypeEnvironment::bindVar( const TypeInstType *typeInst, Type *bindTo, const TypeDecl::Data & data, AssertionSet &need, AssertionSet &have, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
 
                 // remove references from other, so that type variables can only bind to value types
@@ -361 +361 @@
                                 // attempt to unify equivalence class type (which has qualifiers stripped, so they must be restored) with the type to bind to
                                 std::unique_ptr< Type > newType( curClass->type->clone() );
-                                newType->get_qualifiers() = typeInst->get_qualifiers();
+                                newType->tq = typeInst->tq;
                                 if ( unifyInexact( newType.get(), bindTo, *this, need, have, openVars, widen & WidenMode( curClass->allowWidening, true ), indexer, common ) ) {
                                         if ( common ) {
@@ -386 +386 @@
         }
 
-        bool TypeEnvironment::bindVarToVar( TypeInstType *var1, TypeInstType *var2, 
-                        TypeDecl::Data && data, AssertionSet &need, AssertionSet &have, 
+        bool TypeEnvironment::bindVarToVar( const TypeInstType * var1, const TypeInstType * var2,
+                        TypeDecl::Data && data, AssertionSet &need, AssertionSet &have,
                         const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer ) {
 

src/ResolvExpr/TypeEnvironment.h

@@ -9 +9 @@
 // Author           : Richard C. Bilson
 // Created On       : Sun May 17 12:24:58 2015
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Tue Apr 30 23:04:10 2019
-// Update Count     : 9
+// Last Modified By : Andrew Beach
+// Last Modified On : Fri Jul 19 17:00:10 2019
+// Update Count     : 10
 //
 
@@ -40 +40 @@
         // declarations.
         //
-        // I've seen a TU go from 54 minutes to 1 minute 34 seconds with the addition of this 
+        // I've seen a TU go from 54 minutes to 1 minute 34 seconds with the addition of this
         // comparator.
         //
@@ -46 +46 @@
         // memory layout can alter compilation time in unpredictable ways. For example, the placement
         // of a line directive can reorder type pointers with respect to each other so that assertions
-        // are seen in different orders, causing a potentially different number of unification calls 
-        // when resolving assertions. I've seen a TU go from 36 seconds to 27 seconds by reordering 
-        // line directives alone, so it would be nice to fix this comparison so that assertions compare 
-        // more consistently. I've tried to modify this to compare on mangle name instead of type as 
-        // the second comparator, but this causes some assertions to never be recorded. More 
+        // are seen in different orders, causing a potentially different number of unification calls
+        // when resolving assertions. I've seen a TU go from 36 seconds to 27 seconds by reordering
+        // line directives alone, so it would be nice to fix this comparison so that assertions compare
+        // more consistently. I've tried to modify this to compare on mangle name instead of type as
+        // the second comparator, but this causes some assertions to never be recorded. More
         // investigation is needed.
         struct AssertCompare {
-                bool operator()( DeclarationWithType * d1, DeclarationWithType * d2 ) const {
+                bool operator()( const DeclarationWithType * d1, const DeclarationWithType * d2 ) const {
                         int cmp = d1->get_name().compare( d2->get_name() );
                         return cmp < 0 ||
@@ -65 +65 @@
                 AssertionSetValue() : isUsed(false), resnSlot(0) {}
         };
-        typedef std::map< DeclarationWithType *, AssertionSetValue, AssertCompare > AssertionSet;
+        typedef std::map< const DeclarationWithType *, AssertionSetValue, AssertCompare > AssertionSet;
         typedef std::unordered_map< std::string, TypeDecl::Data > OpenVarSet;
 
@@ -78 +78 @@
         struct EqvClass {
                 std::set< std::string > vars;
-                Type *type;
+                Type * type;
                 bool allowWidening;
                 TypeDecl::Data data;
@@ -111 +111 @@
                 bool isEmpty() const { return env.empty(); }
                 void print( std::ostream &os, Indenter indent = {} ) const;
-                
+
                 /// Simply concatenate the second environment onto this one; no safety checks performed
                 void simpleCombine( const TypeEnvironment &second );
@@ -126 +126 @@
                 /// Returns false if fails, but does NOT roll back partial changes.
                 bool combine( const TypeEnvironment& second, OpenVarSet& openVars, const SymTab::Indexer& indexer );
-                
+
                 void extractOpenVars( OpenVarSet &openVars ) const;
                 TypeEnvironment *clone() const { return new TypeEnvironment( *this ); }
@@ -134 +134 @@
                 void addActual( const TypeEnvironment& actualEnv, OpenVarSet& openVars );
 
-                /// Binds the type class represented by `typeInst` to the type `bindTo`; will add 
+                /// Binds the type class represented by `typeInst` to the type `bindTo`; will add
                 /// the class if needed. Returns false on failure.
-                bool bindVar( TypeInstType *typeInst, Type *bindTo, const TypeDecl::Data & data, AssertionSet &need, AssertionSet &have, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
-                
-                /// Binds the type classes represented by `var1` and `var2` together; will add 
+                bool bindVar( const TypeInstType * typeInst, Type * bindTo, const TypeDecl::Data & data, AssertionSet &need, AssertionSet &have, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
+
+                /// Binds the type classes represented by `var1` and `var2` together; will add
                 /// one or both classes if needed. Returns false on failure.
-                bool bindVarToVar( TypeInstType *var1, TypeInstType *var2, TypeDecl::Data && data, AssertionSet &need, AssertionSet &have, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
+                bool bindVarToVar( const TypeInstType * var1, const TypeInstType * var2, TypeDecl::Data && data, AssertionSet &need, AssertionSet &have, const OpenVarSet &openVars, WidenMode widen, const SymTab::Indexer &indexer );
 
                 /// Disallows widening for all bindings in the environment
@@ -151 +151 @@
           private:
                 ClassList env;
-                
+
                 ClassList::iterator internal_lookup( const std::string &var );
         };

src/ResolvExpr/typeops.h

@@ -149 +149 @@
 
         // in Occurs.cc
-        bool occurs( Type * type, std::string varName, const TypeEnvironment & env );
+        bool occurs( const Type * type, const std::string & varName, const TypeEnvironment & env );
         // new AST version in TypeEnvironment.cpp (only place it was used in old AST)
 
@@ -200 +200 @@
 
         // in TypeEnvironment.cc
-        bool isFtype( Type * type );
+        bool isFtype( const Type * type );
 } // namespace ResolvExpr
 

src/SynTree/Type.cc

@@ -9 +9 @@
 // Author           : Richard C. Bilson
 // Created On       : Mon May 18 07:44:20 2015
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Thu Jan 31 21:54:16 2019
-// Update Count     : 43
+// Last Modified By : Andrew Beach
+// Last Modified On : Fri Jul 12 15:48:00 2019
+// Update Count     : 44
 //
 #include "Type.h"
@@ -141 +141 @@
 }
 
+const Type * Type::stripReferences() const {
+        const Type * type;
+        const ReferenceType * ref;
+        for ( type = this; (ref = dynamic_cast<const ReferenceType *>( type )); type = ref->base );
+        return type;
+}
+
 int Type::referenceDepth() const { return 0; }
 

src/SynTree/Type.h

@@ -172 +172 @@
         /// return type without outer references
         Type * stripReferences();
+        const Type * stripReferences() const;
 
         /// return the number of references occuring consecutively on the outermost layer of this type (i.e. do not count references nested within other types)
@@ -256 +257 @@
         BasicType( const Type::Qualifiers & tq, Kind bt, const std::list< Attribute * > & attributes = std::list< Attribute * >() );
 
-        Kind get_kind() { return kind; }
+        Kind get_kind() const { return kind; }
         void set_kind( Kind newValue ) { kind = newValue; }
 

src/Tuples/TupleExpansion.cc

@@ -9 +9 @@
 // Author           : Rodolfo G. Esteves
 // Created On       : Mon May 18 07:44:20 2015
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Wed Feb 13 18:14:12 2019
-// Update Count     : 21
+// Last Modified By : Andrew Beach
+// Last Modified On : Fri Jul 19 14:39:00 2019
+// Update Count     : 22
 //
 
@@ -350 +350 @@
         }
 
+        const TypeInstType * isTtype( const Type * type ) {
+                if ( const TypeInstType * inst = dynamic_cast< const TypeInstType * >( type ) ) {
+                        if ( inst->baseType && inst->baseType->kind == TypeDecl::Ttype ) {
+                                return inst;
+                        }
+                }
+                return nullptr;
+        }
+
         const ast::TypeInstType * isTtype( const ast::Type * type ) {
                 if ( const ast::TypeInstType * inst = dynamic_cast< const ast::TypeInstType * >( type ) ) {
@@ -364 +373 @@
                         ImpurityDetector( bool ignoreUnique ) : ignoreUnique( ignoreUnique ) {}
 
-                        void previsit( ApplicationExpr * appExpr ) {
+                        void previsit( const ApplicationExpr * appExpr ) {
                                 visit_children = false;
-                                if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
-                                        if ( function->get_linkage() == LinkageSpec::Intrinsic ) {
-                                                if ( function->get_name() == "*?" || function->get_name() == "?[?]" ) {
+                                if ( const DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
+                                        if ( function->linkage == LinkageSpec::Intrinsic ) {
+                                                if ( function->name == "*?" || function->name == "?[?]" ) {
                                                         // intrinsic dereference, subscript are pure, but need to recursively look for impurity
                                                         visit_children = true;
@@ -377 +386 @@
                                 maybeImpure = true;
                         }
-                        void previsit( UntypedExpr * ) { maybeImpure = true; visit_children = false; }
-                        void previsit( UniqueExpr * ) {
+                        void previsit( const UntypedExpr * ) { maybeImpure = true; visit_children = false; }
+                        void previsit( const UniqueExpr * ) {
                                 if ( ignoreUnique ) {
                                         // bottom out at unique expression.
@@ -393 +402 @@
         } // namespace
 
-        bool maybeImpure( Expression * expr ) {
+        bool maybeImpure( const Expression * expr ) {
                 PassVisitor<ImpurityDetector> detector( false );
                 expr->accept( detector );
@@ -399 +408 @@
         }
 
-        bool maybeImpureIgnoreUnique( Expression * expr ) {
+        bool maybeImpureIgnoreUnique( const Expression * expr ) {
                 PassVisitor<ImpurityDetector> detector( true );
                 expr->accept( detector );

src/Tuples/Tuples.h

@@ -52 +52 @@
         /// returns a TypeInstType if `type` is a ttype, nullptr otherwise
         TypeInstType * isTtype( Type * type );
+        const TypeInstType * isTtype( const Type * type );
         const ast::TypeInstType * isTtype( const ast::Type * type );
 
         /// returns true if the expression may contain side-effects.
-        bool maybeImpure( Expression * expr );
+        bool maybeImpure( const Expression * expr );
         bool maybeImpure( const ast::Expr * expr );
 
         /// Returns true if the expression may contain side-effect,
         /// ignoring the presence of unique expressions.
-        bool maybeImpureIgnoreUnique( Expression * expr );
+        bool maybeImpureIgnoreUnique( const Expression * expr );
         bool maybeImpureIgnoreUnique( const ast::Expr * expr );
 } // namespace Tuples