Changeset 6e50a6b for src/SymTab

Timestamp:

Jun 18, 2021, 12:20:59 PM (4 years ago)

Author:

Michael Brooks <mlbrooks@…>

Branches:

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

Children:

c7d8696a

Parents:

dcbfcbc

Message:

Implementing language-provided syntax for (array) dimensions.

Former z(i) and Z(N) macros are eliminated.

Location:

src/SymTab

Files:

• Indexer.cc (modified) (3 diffs)
• Indexer.h (modified) (2 diffs)
• Validate.cc (modified) (14 diffs)

src/SymTab/Indexer.cc

@@ -74 +74 @@
         }
 
-        Indexer::Indexer()
+        Indexer::Indexer( bool trackIdentifiers )
         : idTable(), typeTable(), structTable(), enumTable(), unionTable(), traitTable(),
-          prevScope(), scope( 0 ), repScope( 0 ) { ++* stats().count; }
+          prevScope(), scope( 0 ), repScope( 0 ), trackIdentifiers( trackIdentifiers ) { ++* stats().count; }
 
         Indexer::~Indexer() {
@@ -110 +110 @@
 
         void Indexer::lookupId( const std::string & id, std::list< IdData > &out ) const {
+                assert( trackIdentifiers );
+
                 ++* stats().lookup_calls;
                 if ( ! idTable ) return;
@@ -434 +436 @@
                         const Declaration * deleteStmt ) {
                 ++* stats().add_calls;
+                if ( ! trackIdentifiers ) return;
                 const std::string &name = decl->name;
                 if ( name == "" ) return;

src/SymTab/Indexer.h

@@ -31 +31 @@
         class Indexer : public std::enable_shared_from_this<SymTab::Indexer> {
         public:
-                explicit Indexer();
+                explicit Indexer( bool trackIdentifiers = true );
                 virtual ~Indexer();
 
@@ -180 +180 @@
                 /// returns true if there exists a declaration with C linkage and the given name with a different mangled name
                 bool hasIncompatibleCDecl( const std::string & id, const std::string & mangleName ) const;
+
+            bool trackIdentifiers;
         };
 } // namespace SymTab

src/SymTab/Validate.cc

@@ -105 +105 @@
 
         struct FixQualifiedTypes final : public WithIndexer {
+                FixQualifiedTypes() : WithIndexer(false) {}
                 Type * postmutate( QualifiedType * );
         };
@@ -174 +175 @@
         };
 
+        /// Does early resolution on the expressions that give enumeration constants their values
+        struct ResolveEnumInitializers final : public WithIndexer, public WithGuards, public WithVisitorRef<ResolveEnumInitializers>, public WithShortCircuiting {
+                ResolveEnumInitializers( const Indexer * indexer );
+                void postvisit( EnumDecl * enumDecl );
+
+          private:
+                const Indexer * local_indexer;
+
+        };
+
         /// Replaces array and function types in forall lists by appropriate pointer type and assigns each Object and Function declaration a unique ID.
         struct ForallPointerDecay_old final {
@@ -260 +271 @@
                 void previsit( StructInstType * inst );
                 void previsit( UnionInstType * inst );
+        };
+
+        /// desugar declarations and uses of dimension paramaters like [N],
+        /// from type-system managed values, to tunnneling via ordinary types,
+        /// as char[-] in and sizeof(-) out
+        struct TranslateDimensionGenericParameters : public WithIndexer, public WithGuards {
+                static void translateDimensions( std::list< Declaration * > &translationUnit );
+                TranslateDimensionGenericParameters();
+
+                bool nextVisitedNodeIsChildOfSUIT = false; // SUIT = Struct or Union -Inst Type
+                bool visitingChildOfSUIT = false;
+                void changeState_ChildOfSUIT( bool newVal );
+                void premutate( StructInstType * sit );
+                void premutate( UnionInstType * uit );
+                void premutate( BaseSyntaxNode * node );
+
+                TypeDecl * postmutate( TypeDecl * td );
+                Expression * postmutate( DimensionExpr * de );
+                Expression * postmutate( Expression * e );
         };
 
@@ -307 +337 @@
                 PassVisitor<EnumAndPointerDecay_old> epc;
                 PassVisitor<LinkReferenceToTypes_old> lrt( nullptr );
+                PassVisitor<ResolveEnumInitializers> rei( nullptr );
                 PassVisitor<ForallPointerDecay_old> fpd;
                 PassVisitor<CompoundLiteral> compoundliteral;
@@ -326 +357 @@
                         Stats::Heap::newPass("validate-B");
                         Stats::Time::BlockGuard guard("validate-B");
-                        Stats::Time::TimeBlock("Link Reference To Types", [&]() {
-                                acceptAll( translationUnit, lrt ); // must happen before autogen, because sized flag needs to propagate to generated functions
-                        });
-                        Stats::Time::TimeBlock("Fix Qualified Types", [&]() {
-                                mutateAll( translationUnit, fixQual ); // must happen after LinkReferenceToTypes_old, because aggregate members are accessed
-                        });
-                        Stats::Time::TimeBlock("Hoist Structs", [&]() {
-                                HoistStruct::hoistStruct( translationUnit ); // must happen after EliminateTypedef, so that aggregate typedefs occur in the correct order
-                        });
-                        Stats::Time::TimeBlock("Eliminate Typedefs", [&]() {
-                                EliminateTypedef::eliminateTypedef( translationUnit ); //
-                        });
+                        acceptAll( translationUnit, lrt ); // must happen before autogen, because sized flag needs to propagate to generated functions
+                        mutateAll( translationUnit, fixQual ); // must happen after LinkReferenceToTypes_old, because aggregate members are accessed
+                        HoistStruct::hoistStruct( translationUnit );
+                        EliminateTypedef::eliminateTypedef( translationUnit );
                 }
                 {
                         Stats::Heap::newPass("validate-C");
                         Stats::Time::BlockGuard guard("validate-C");
-                        acceptAll( translationUnit, genericParams );  // check as early as possible - can't happen before LinkReferenceToTypes_old
-                        ReturnChecker::checkFunctionReturns( translationUnit );
-                        InitTweak::fixReturnStatements( translationUnit ); // must happen before autogen
+                        Stats::Time::TimeBlock("Validate Generic Parameters", [&]() {
+                                acceptAll( translationUnit, genericParams );  // check as early as possible - can't happen before LinkReferenceToTypes_old; observed failing when attempted before eliminateTypedef
+                        });
+                        Stats::Time::TimeBlock("Translate Dimensions", [&]() {
+                                TranslateDimensionGenericParameters::translateDimensions( translationUnit );
+                        });
+                        Stats::Time::TimeBlock("Resolve Enum Initializers", [&]() {
+                                acceptAll( translationUnit, rei ); // must happen after translateDimensions because rei needs identifier lookup, which needs name mangling
+                        });
+                        Stats::Time::TimeBlock("Check Function Returns", [&]() {
+                                ReturnChecker::checkFunctionReturns( translationUnit );
+                        });
+                        Stats::Time::TimeBlock("Fix Return Statements", [&]() {
+                                InitTweak::fixReturnStatements( translationUnit ); // must happen before autogen
+                        });
                 }
                 {
@@ -644 +679 @@
         }
 
-        LinkReferenceToTypes_old::LinkReferenceToTypes_old( const Indexer * other_indexer ) {
+        LinkReferenceToTypes_old::LinkReferenceToTypes_old( const Indexer * other_indexer ) : WithIndexer( false ) {
                 if ( other_indexer ) {
                         local_indexer = other_indexer;
@@ -664 +699 @@
         }
 
-        void checkGenericParameters( ReferenceToType * inst ) {
-                for ( Expression * param : inst->parameters ) {
-                        if ( ! dynamic_cast< TypeExpr * >( param ) ) {
-                                SemanticError( inst, "Expression parameters for generic types are currently unsupported: " );
-                        }
-                }
-        }
-
         void LinkReferenceToTypes_old::postvisit( StructInstType * structInst ) {
                 const StructDecl * st = local_indexer->lookupStruct( structInst->name );
@@ -682 +709 @@
                         forwardStructs[ structInst->name ].push_back( structInst );
                 } // if
-                checkGenericParameters( structInst );
         }
 
@@ -695 +721 @@
                         forwardUnions[ unionInst->name ].push_back( unionInst );
                 } // if
-                checkGenericParameters( unionInst );
         }
 
@@ -807 +832 @@
                                 forwardEnums.erase( fwds );
                         } // if
-
-                        for ( Declaration * member : enumDecl->members ) {
-                                ObjectDecl * field = strict_dynamic_cast<ObjectDecl *>( member );
-                                if ( field->init ) {
-                                        // need to resolve enumerator initializers early so that other passes that determine if an expression is constexpr have the appropriate information.
-                                        SingleInit * init = strict_dynamic_cast<SingleInit *>( field->init );
-                                        ResolvExpr::findSingleExpression( init->value, new BasicType( Type::Qualifiers(), BasicType::SignedInt ), indexer );
-                                }
-                        }
                 } // if
         }
@@ -878 +894 @@
                                 typeInst->set_isFtype( typeDecl->kind == TypeDecl::Ftype );
                         } // if
+                } // if
+        }
+
+        ResolveEnumInitializers::ResolveEnumInitializers( const Indexer * other_indexer ) : WithIndexer( true ) {
+                if ( other_indexer ) {
+                        local_indexer = other_indexer;
+                } else {
+                        local_indexer = &indexer;
+                } // if
+        }
+
+        void ResolveEnumInitializers::postvisit( EnumDecl * enumDecl ) {
+                if ( enumDecl->body ) {
+                        for ( Declaration * member : enumDecl->members ) {
+                                ObjectDecl * field = strict_dynamic_cast<ObjectDecl *>( member );
+                                if ( field->init ) {
+                                        // need to resolve enumerator initializers early so that other passes that determine if an expression is constexpr have the appropriate information.
+                                        SingleInit * init = strict_dynamic_cast<SingleInit *>( field->init );
+                                        ResolvExpr::findSingleExpression( init->value, new BasicType( Type::Qualifiers(), BasicType::SignedInt ), indexer );
+                                }
+                        }
                 } // if
         }
@@ -1223 +1260 @@
         }
 
+        // Test for special name on a generic parameter.  Special treatment for the
+        // special name is a bootstrapping hack.  In most cases, the worlds of T's
+        // and of N's don't overlap (normal treamtemt).  The foundations in
+        // array.hfa use tagging for both types and dimensions.  Tagging treats
+        // its subject parameter even more opaquely than T&, which assumes it is
+        // possible to have a pointer/reference to such an object.  Tagging only
+        // seeks to identify the type-system resident at compile time.  Both N's
+        // and T's can make tags.  The tag definition uses the special name, which
+        // is treated as "an N or a T."  This feature is not inteded to be used
+        // outside of the definition and immediate uses of a tag.
+        static inline bool isReservedTysysIdOnlyName( const std::string & name ) {
+                // name's prefix was __CFA_tysys_id_only, before it got wrapped in __..._generic
+                int foundAt = name.find("__CFA_tysys_id_only");
+                if (foundAt == 0) return true;
+                if (foundAt == 2 && name[0] == '_' && name[1] == '_') return true;
+                return false;
+        }
+
         template< typename Aggr >
         void validateGeneric( Aggr * inst ) {
@@ -1239 +1294 @@
                         TypeSubstitution sub;
                         auto paramIter = params->begin();
-                        for ( size_t i = 0; paramIter != params->end(); ++paramIter, ++i ) {
-                                if ( i < args.size() ) {
-                                        TypeExpr * expr = strict_dynamic_cast< TypeExpr * >( * std::next( args.begin(), i ) );
-                                        sub.add( (* paramIter)->get_name(), expr->get_type()->clone() );
-                                } else if ( i == args.size() ) {
+                        auto argIter = args.begin();
+                        for ( ; paramIter != params->end(); ++paramIter, ++argIter ) {
+                                if ( argIter != args.end() ) {
+                                        TypeExpr * expr = dynamic_cast< TypeExpr * >( * argIter );
+                                        if ( expr ) {
+                                                sub.add( (* paramIter)->get_name(), expr->get_type()->clone() );
+                                        }
+                                } else {
                                         Type * defaultType = (* paramIter)->get_init();
                                         if ( defaultType ) {
                                                 args.push_back( new TypeExpr( defaultType->clone() ) );
                                                 sub.add( (* paramIter)->get_name(), defaultType->clone() );
+                                                argIter = std::prev(args.end());
+                                        } else {
+                                                SemanticError( inst, "Too few type arguments in generic type " );
                                         }
                                 }
+                                assert( argIter != args.end() );
+                                bool typeParamDeclared = (*paramIter)->kind != TypeDecl::Kind::Dimension;
+                                bool typeArgGiven;
+                                if ( isReservedTysysIdOnlyName( (*paramIter)->name ) ) {
+                                        // coerce a match when declaration is reserved name, which means "either"
+                                        typeArgGiven = typeParamDeclared;
+                                } else {
+                                        typeArgGiven = dynamic_cast< TypeExpr * >( * argIter );
+                                }
+                                if ( ! typeParamDeclared &&   typeArgGiven ) SemanticError( inst, "Type argument given for value parameter: " );
+                                if (   typeParamDeclared && ! typeArgGiven ) SemanticError( inst, "Expression argument given for type parameter: " );
                         }
 
                         sub.apply( inst );
-                        if ( args.size() < params->size() ) SemanticError( inst, "Too few type arguments in generic type " );
                         if ( args.size() > params->size() ) SemanticError( inst, "Too many type arguments in generic type " );
                 }
@@ -1264 +1335 @@
         void ValidateGenericParameters::previsit( UnionInstType * inst ) {
                 validateGeneric( inst );
+        }
+
+        void TranslateDimensionGenericParameters::translateDimensions( std::list< Declaration * > &translationUnit ) {
+                PassVisitor<TranslateDimensionGenericParameters> translator;
+                mutateAll( translationUnit, translator );
+        }
+
+        TranslateDimensionGenericParameters::TranslateDimensionGenericParameters() : WithIndexer( false ) {}
+
+        // Declaration of type variable:           forall( [N] )          ->  forall( N & | sized( N ) )
+        TypeDecl * TranslateDimensionGenericParameters::postmutate( TypeDecl * td ) {
+                if ( td->kind == TypeDecl::Dimension ) {
+                        td->kind = TypeDecl::Dtype;
+                        if ( ! isReservedTysysIdOnlyName( td->name ) ) {
+                                td->sized = true;
+                        }
+                }
+                return td;
+        }
+
+        // Situational awareness:
+        // array( float, [[currentExpr]]     )  has  visitingChildOfSUIT == true
+        // array( float, [[currentExpr]] - 1 )  has  visitingChildOfSUIT == false
+        // size_t x =    [[currentExpr]]        has  visitingChildOfSUIT == false
+        void TranslateDimensionGenericParameters::changeState_ChildOfSUIT( bool newVal ) {
+                GuardValue( nextVisitedNodeIsChildOfSUIT );
+                GuardValue( visitingChildOfSUIT );
+                visitingChildOfSUIT = nextVisitedNodeIsChildOfSUIT;
+                nextVisitedNodeIsChildOfSUIT = newVal;
+        }
+        void TranslateDimensionGenericParameters::premutate( StructInstType * sit ) {
+                (void) sit;
+                changeState_ChildOfSUIT(true);
+        }
+        void TranslateDimensionGenericParameters::premutate( UnionInstType * uit ) {
+                (void) uit;
+                changeState_ChildOfSUIT(true);
+        }
+        void TranslateDimensionGenericParameters::premutate( BaseSyntaxNode * node ) {
+                (void) node;
+                changeState_ChildOfSUIT(false);
+        }
+
+        // Passing values as dimension arguments:  array( float,     7 )  -> array( float, char[             7 ] )
+        // Consuming dimension parameters:         size_t x =    N - 1 ;  -> size_t x =          sizeof(N) - 1   ;
+        // Intertwined reality:                    array( float, N     )  -> array( float,              N        )
+        //                                         array( float, N - 1 )  -> array( float, char[ sizeof(N) - 1 ] )
+        // Intertwined case 1 is not just an optimization.
+        // Avoiding char[sizeof(-)] is necessary to enable the call of f to bind the value of N, in:
+        //   forall([N]) void f( array(float, N) & );
+        //   array(float, 7) a;
+        //   f(a);
+
+        Expression * TranslateDimensionGenericParameters::postmutate( DimensionExpr * de ) {
+                // Expression de is an occurrence of N in LHS of above examples.
+                // Look up the name that de references.
+                // If we are in a struct body, then this reference can be to an entry of the stuct's forall list.
+                // Whether or not we are in a struct body, this reference can be to an entry of a containing function's forall list.
+                // If we are in a struct body, then the stuct's forall declarations are innermost (functions don't occur in structs).
+                // Thus, a potential struct's declaration is highest priority.
+                // A struct's forall declarations are already renamed with _generic_ suffix.  Try that name variant first.
+
+                std::string useName = "__" + de->name + "_generic_";
+                TypeDecl * namedParamDecl = const_cast<TypeDecl *>( strict_dynamic_cast<const TypeDecl *, nullptr >( indexer.lookupType( useName ) ) );
+
+                if ( ! namedParamDecl ) {
+                        useName = de->name;
+                        namedParamDecl = const_cast<TypeDecl *>( strict_dynamic_cast<const TypeDecl *, nullptr >( indexer.lookupType( useName ) ) );
+                }
+
+                // Expect to find it always.  A misspelled name would have been parsed as an identifier.
+                assert( namedParamDecl && "Type-system-managed value name not found in symbol table" );
+
+                delete de;
+
+                TypeInstType * refToDecl = new TypeInstType( 0, useName, namedParamDecl );
+
+                if ( visitingChildOfSUIT ) {
+                        // As in postmutate( Expression * ), topmost expression needs a TypeExpr wrapper
+                        // But avoid ArrayType-Sizeof
+                        return new TypeExpr( refToDecl );
+                } else {
+                        // the N occurrence is being used directly as a runtime value,
+                        // if we are in a type instantiation, then the N is within a bigger value computation
+                        return new SizeofExpr( refToDecl );
+                }
+        }
+
+        Expression * TranslateDimensionGenericParameters::postmutate( Expression * e ) {
+                if ( visitingChildOfSUIT ) {
+                        // e is an expression used as an argument to instantiate a type
+                        if (! dynamic_cast< TypeExpr * >( e ) ) {
+                                // e is a value expression
+                                // but not a DimensionExpr, which has a distinct postmutate
+                                Type * typeExprContent = new ArrayType( 0, new BasicType( 0, BasicType::Char ), e, true, false );
+                                TypeExpr * result = new TypeExpr( typeExprContent );
+                                return result;
+                        }
+                }
+                return e;
         }