Changeset 83c7e3c

Timestamp:

Dec 23, 2020, 6:37:35 PM (3 years ago)

Author:

caparsons <caparson@…>

Branches:

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

Children:

a3a76ea, c20533ea

Parents:

4c19647 (diff), 09867ec (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/GenInit.cc (modified) (3 diffs)
• ResolvExpr/CandidateFinder.cpp (modified) (1 diff)
• ResolvExpr/ResolvMode.h (modified) (1 diff)
• SymTab/Validate.cc (modified) (6 diffs)

src/InitTweak/GenInit.cc

@@ -122 +122 @@
         };
 
+        struct HoistArrayDimension_NoResolve final : public WithDeclsToAdd, public WithShortCircuiting, public WithGuards {
+                /// hoist dimension from array types in object declaration so that it uses a single
+                /// const variable of type size_t, so that side effecting array dimensions are only
+                /// computed once.
+                static void hoistArrayDimension( std::list< Declaration * > & translationUnit );
+
+                void premutate( ObjectDecl * objectDecl );
+                DeclarationWithType * postmutate( ObjectDecl * objectDecl );
+                void premutate( FunctionDecl *functionDecl );
+                // should not traverse into any of these declarations to find objects
+                // that need to be constructed or destructed
+                void premutate( AggregateDecl * ) { visit_children = false; }
+                void premutate( NamedTypeDecl * ) { visit_children = false; }
+                void premutate( FunctionType * ) { visit_children = false; }
+
+                void hoist( Type * type );
+
+                Type::StorageClasses storageClasses;
+                bool inFunction = false;
+        };
+
         void genInit( std::list< Declaration * > & translationUnit ) {
-                HoistArrayDimension::hoistArrayDimension( translationUnit );
+                if (!useNewAST) {
+                        HoistArrayDimension::hoistArrayDimension( translationUnit );
+                }
+                else {
+                        HoistArrayDimension_NoResolve::hoistArrayDimension( translationUnit );
+                }
                 fixReturnStatements( translationUnit );
 
@@ -196 +222 @@
 
                         // need to resolve array dimensions in order to accurately determine if constexpr
-                        if (!useNewAST) {
-                                ResolvExpr::findSingleExpression( arrayType->dimension, Validate::SizeType->clone(), indexer );
-                                // array is variable-length when the dimension is not constexpr
-                                arrayType->isVarLen = ! isConstExpr( arrayType->dimension );
-                        }
+                        ResolvExpr::findSingleExpression( arrayType->dimension, Validate::SizeType->clone(), indexer );
+                        // array is variable-length when the dimension is not constexpr
+                        arrayType->isVarLen = ! isConstExpr( arrayType->dimension );
                         // don't need to hoist dimension if it's definitely pure - only need to if there's potential for side effects.
                         // xxx - hoisting has no side effects anyways, so don't skip since we delay resolve
@@ -218 +242 @@
 
         void HoistArrayDimension::premutate( FunctionDecl * ) {
+                GuardValue( inFunction );
+                inFunction = true;
+        }
+
+        // precompute array dimension expression, because constructor generation may duplicate it,
+        // which would be incorrect if it is a side-effecting computation.
+        void HoistArrayDimension_NoResolve::hoistArrayDimension( std::list< Declaration * > & translationUnit ) {
+                PassVisitor<HoistArrayDimension_NoResolve> hoister;
+                mutateAll( translationUnit, hoister );
+        }
+
+        void HoistArrayDimension_NoResolve::premutate( ObjectDecl * objectDecl ) {
+                GuardValue( storageClasses );
+                storageClasses = objectDecl->get_storageClasses();
+        }
+
+        DeclarationWithType * HoistArrayDimension_NoResolve::postmutate( ObjectDecl * objectDecl ) {
+                hoist( objectDecl->get_type() );
+                return objectDecl;
+        }
+
+        void HoistArrayDimension_NoResolve::hoist( Type * type ) {
+                // if in function, generate const size_t var
+                static UniqueName dimensionName( "_array_dim" );
+
+                // C doesn't allow variable sized arrays at global scope or for static variables, so don't hoist dimension.
+                if ( ! inFunction ) return;
+                if ( storageClasses.is_static ) return;
+
+                if ( ArrayType * arrayType = dynamic_cast< ArrayType * >( type ) ) {
+                        if ( ! arrayType->get_dimension() ) return; // xxx - recursive call to hoist?
+                        // don't need to hoist dimension if it's definitely pure - only need to if there's potential for side effects.
+                        // xxx - hoisting has no side effects anyways, so don't skip since we delay resolve
+                        // still try to detect constant expressions
+                        if ( ! Tuples::maybeImpure( arrayType->dimension ) ) return;
+
+                        ObjectDecl * arrayDimension = new ObjectDecl( dimensionName.newName(), storageClasses, LinkageSpec::C, 0, Validate::SizeType->clone(), new SingleInit( arrayType->get_dimension() ) );
+                        arrayDimension->get_type()->set_const( true );
+
+                        arrayType->set_dimension( new VariableExpr( arrayDimension ) );
+                        declsToAddBefore.push_back( arrayDimension );
+
+                        hoist( arrayType->get_base() );
+                        return;
+                }
+        }
+
+        void HoistArrayDimension_NoResolve::premutate( FunctionDecl * ) {
                 GuardValue( inFunction );
                 inFunction = true;

src/ResolvExpr/CandidateFinder.cpp

@@ -905 +905 @@
                         // xxx - is it possible that handleTupleAssignment and main finder both produce candidates?
                         // this means there exists ctor/assign functions with a tuple as first parameter.
-                        funcFinder.find( untypedExpr->func, selfFinder.candidates.empty() ? ResolvMode::withAdjustment() : ResolvMode::withoutFailFast() );
+                        ResolvMode mode = {
+                                true, // adjust
+                                !untypedExpr->func.as<ast::NameExpr>(), // prune if not calling by name
+                                selfFinder.candidates.empty() // failfast if other options are not found
+                        };
+                        funcFinder.find( untypedExpr->func, mode );
                         // short-circuit if no candidates
                         // if ( funcFinder.candidates.empty() ) return;

src/ResolvExpr/ResolvMode.h

@@ -23 +23 @@
                 const bool failFast;         ///< Fail on no resulting alternatives? [true]
 
-        private:
                 constexpr ResolvMode(bool a, bool p, bool ff) 
                 : adjust(a), prune(p), failFast(ff) {}
 
-        public:
                 /// Default settings
                 constexpr ResolvMode() : adjust(false), prune(true), failFast(true) {}

src/SymTab/Validate.cc

@@ -271 +271 @@
         };
 
-        struct ArrayLength : public WithIndexer {
+        struct InitializerLength {
                 /// for array types without an explicit length, compute the length and store it so that it
                 /// is known to the rest of the phases. For example,
@@ -282 +282 @@
 
                 void previsit( ObjectDecl * objDecl );
+        };
+
+        struct ArrayLength : public WithIndexer {
+                static void computeLength( std::list< Declaration * > & translationUnit );
+
                 void previsit( ArrayType * arrayType );
         };
@@ -382 +387 @@
                                         FixObjectType::fix, translationUnit);
                         }
-                        Stats::Time::TimeCall("Array Length",
-                                ArrayLength::computeLength, translationUnit);
+                        Stats::Time::TimeCall("Initializer Length",
+                                InitializerLength::computeLength, translationUnit);
+                        if (!useNewAST) {
+                                Stats::Time::TimeCall("Array Length",
+                                        ArrayLength::computeLength, translationUnit);
+                        }
                         Stats::Time::TimeCall("Find Special Declarations",
                                 Validate::findSpecialDecls, translationUnit);
@@ -1332 +1341 @@
         }
 
+        void InitializerLength::computeLength( std::list< Declaration * > & translationUnit ) {
+                PassVisitor<InitializerLength> len;
+                acceptAll( translationUnit, len );
+        }
+
         void ArrayLength::computeLength( std::list< Declaration * > & translationUnit ) {
                 PassVisitor<ArrayLength> len;
@@ -1337 +1351 @@
         }
 
-        void ArrayLength::previsit( ObjectDecl * objDecl ) {
+        void InitializerLength::previsit( ObjectDecl * objDecl ) {
                 if ( ArrayType * at = dynamic_cast< ArrayType * >( objDecl->type ) ) {
                         if ( at->dimension ) return;
@@ -1347 +1361 @@
 
         void ArrayLength::previsit( ArrayType * type ) {
-                if (!useNewAST) {
-                        if ( type->dimension ) {
-                                // need to resolve array dimensions early so that constructor code can correctly determine
-                                // if a type is a VLA (and hence whether its elements need to be constructed)
-                                ResolvExpr::findSingleExpression( type->dimension, Validate::SizeType->clone(), indexer );
-
-                                // must re-evaluate whether a type is a VLA, now that more information is available
-                                // (e.g. the dimension may have been an enumerator, which was unknown prior to this step)
-                                type->isVarLen = ! InitTweak::isConstExpr( type->dimension );
-                        }
+                if ( type->dimension ) {
+                        // need to resolve array dimensions early so that constructor code can correctly determine
+                        // if a type is a VLA (and hence whether its elements need to be constructed)
+                        ResolvExpr::findSingleExpression( type->dimension, Validate::SizeType->clone(), indexer );
+
+                        // must re-evaluate whether a type is a VLA, now that more information is available
+                        // (e.g. the dimension may have been an enumerator, which was unknown prior to this step)
+                        type->isVarLen = ! InitTweak::isConstExpr( type->dimension );
                 }
         }