Changeset 6e50a6b

Timestamp:

Jun 18, 2021, 12:20:59 PM (21 months ago)

Author:

Michael Brooks <mlbrooks@…>

Branches:

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.

Files:

• libcfa/src/containers/array.hfa (modified) (3 diffs)
• src/AST/Convert.cpp (modified) (1 diff)
• src/AST/Decl.cpp (modified) (1 diff)
• src/AST/Decl.hpp (modified) (1 diff)
• src/CodeGen/CodeGenerator.cc (modified) (1 diff)
• src/CodeGen/CodeGenerator.h (modified) (1 diff)
• src/Common/PassVisitor.h (modified) (3 diffs)
• src/Common/PassVisitor.impl.h (modified) (4 diffs)
• src/Parser/DeclarationNode.cc (modified) (1 diff)
• src/Parser/ExpressionNode.cc (modified) (1 diff)
• src/Parser/ParseNode.h (modified) (1 diff)
• src/Parser/TypedefTable.cc (modified) (2 diffs)
• src/Parser/parser.yy (modified) (5 diffs)
• src/SymTab/Indexer.cc (modified) (3 diffs)
• src/SymTab/Indexer.h (modified) (2 diffs)
• src/SymTab/Validate.cc (modified) (14 diffs)
• src/SynTree/Declaration.h (modified) (1 diff)
• src/SynTree/Expression.h (modified) (1 diff)
• src/SynTree/Mutator.h (modified) (1 diff)
• src/SynTree/SynTree.h (modified) (1 diff)
• src/SynTree/TypeDecl.cc (modified) (1 diff)
• src/SynTree/TypeExpr.cc (modified) (1 diff)
• src/SynTree/Visitor.h (modified) (1 diff)
• tests/array-container/.expect/language-dim-mismatch.txt (added)
• tests/array-container/array-basic.cfa (modified) (3 diffs)
• tests/array-container/array-md-sbscr-cases.cfa (modified) (2 diffs)
• tests/array-container/language-dim-mismatch.cfa (added)

libcfa/src/containers/array.hfa

@@ -1 +1 @@
 
 
-// a type whose size is n
-#define Z(n) char[n]
-
-// the inverse of Z(-)
-#define z(N) sizeof(N)
-
-forall( T & ) struct tag {};
+forall( __CFA_tysys_id_only_X & ) struct tag {};
 #define ttag(T) ((tag(T)){})
-#define ztag(n) ttag(Z(n))
+#define ztag(n) ttag(n)
 
 
@@ -18 +12 @@
 forall( [N], S & | sized(S), Timmed &, Tbase & ) {
     struct arpk {
-        S strides[z(N)];
+        S strides[N];
     };
 
@@ -56 +50 @@
 
     static inline size_t ?`len( arpk(N, S, Timmed, Tbase) & a ) {
-        return z(N);
+        return N;
     }
 
     // workaround #226 (and array relevance thereof demonstrated in mike102/otype-slow-ndims.cfa)
     static inline void ?{}( arpk(N, S, Timmed, Tbase) & this ) {
-        void ?{}( S (&inner)[z(N)] ) {}
+        void ?{}( S (&inner)[N] ) {}
         ?{}(this.strides);
     }
     static inline void ^?{}( arpk(N, S, Timmed, Tbase) & this ) {
-        void ^?{}( S (&inner)[z(N)] ) {}
+        void ^?{}( S (&inner)[N] ) {}
         ^?{}(this.strides);
     }

src/AST/Convert.cpp

@@ -2415 +2415 @@
         }
 
+        virtual void visit( const DimensionExpr * old ) override final {
+                // DimensionExpr gets desugared away in Validate.
+                // As long as new-AST passes don't use it, this cheap-cheerful error
+                // detection helps ensure that these occurrences have been compiled
+                // away, as expected.  To move the DimensionExpr boundary downstream
+                // or move the new-AST translation boundary upstream, implement
+                // DimensionExpr in the new AST and implement a conversion.
+                (void) old;
+                assert(false && "DimensionExpr should not be present at new-AST boundary");
+        }
+
         virtual void visit( const AsmExpr * old ) override final {
                 this->node = visitBaseExpr( old,

src/AST/Decl.cpp

@@ -78 +78 @@
 
 const char * TypeDecl::typeString() const {
-        static const char * kindNames[] = { "sized data type", "sized data type", "sized object type", "sized function type", "sized tuple type", "sized array length type" };
+        static const char * kindNames[] = { "sized data type", "sized data type", "sized object type", "sized function type", "sized tuple type", "sized length value" };
         static_assert( sizeof(kindNames) / sizeof(kindNames[0]) == TypeDecl::NUMBER_OF_KINDS, "typeString: kindNames is out of sync." );
         assertf( kind < TypeDecl::NUMBER_OF_KINDS, "TypeDecl kind is out of bounds." );

src/AST/Decl.hpp

@@ -175 +175 @@
 class TypeDecl final : public NamedTypeDecl {
   public:
-        enum Kind { Dtype, DStype, Otype, Ftype, Ttype, ALtype, NUMBER_OF_KINDS };
+        enum Kind { Dtype, DStype, Otype, Ftype, Ttype, Dimension, NUMBER_OF_KINDS };
 
         Kind kind;

src/CodeGen/CodeGenerator.cc

@@ -589 +589 @@
                         output << nameExpr->get_name();
                 } // if
+        }
+
+        void CodeGenerator::postvisit( DimensionExpr * dimensionExpr ) {
+                extension( dimensionExpr );
+                output << "/*non-type*/" << dimensionExpr->get_name();
         }
 

src/CodeGen/CodeGenerator.h

@@ -92 +92 @@
                 void postvisit( TupleIndexExpr * tupleExpr );
                 void postvisit( TypeExpr *typeExpr );
+                void postvisit( DimensionExpr *dimensionExpr );
                 void postvisit( AsmExpr * );
                 void postvisit( StmtExpr * );

src/Common/PassVisitor.h

@@ -167 +167 @@
         virtual void visit( TypeExpr * typeExpr ) override final;
         virtual void visit( const TypeExpr * typeExpr ) override final;
+        virtual void visit( DimensionExpr * dimensionExpr ) override final;
+        virtual void visit( const DimensionExpr * dimensionExpr ) override final;
         virtual void visit( AsmExpr * asmExpr ) override final;
         virtual void visit( const AsmExpr * asmExpr ) override final;
@@ -309 +311 @@
         virtual Expression * mutate( CommaExpr * commaExpr ) override final;
         virtual Expression * mutate( TypeExpr * typeExpr ) override final;
+        virtual Expression * mutate( DimensionExpr * dimensionExpr ) override final;
         virtual Expression * mutate( AsmExpr * asmExpr ) override final;
         virtual Expression * mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) override final;
@@ -542 +545 @@
 class WithIndexer {
 protected:
-        WithIndexer() {}
+        WithIndexer( bool trackIdentifiers = true ) : indexer(trackIdentifiers) {}
         ~WithIndexer() {}
 

src/Common/PassVisitor.impl.h

@@ -2519 +2519 @@
 
 //--------------------------------------------------------------------------
+// DimensionExpr
+template< typename pass_type >
+void PassVisitor< pass_type >::visit( DimensionExpr * node ) {
+        VISIT_START( node );
+
+        indexerScopedAccept( node->result, *this );
+
+        VISIT_END( node );
+}
+
+template< typename pass_type >
+void PassVisitor< pass_type >::visit( const DimensionExpr * node ) {
+        VISIT_START( node );
+
+        indexerScopedAccept( node->result, *this );
+
+        VISIT_END( node );
+}
+
+template< typename pass_type >
+Expression * PassVisitor< pass_type >::mutate( DimensionExpr * node ) {
+        MUTATE_START( node );
+
+        indexerScopedMutate( node->env   , *this );
+        indexerScopedMutate( node->result, *this );
+
+        MUTATE_END( Expression, node );
+}
+
+//--------------------------------------------------------------------------
 // AsmExpr
 template< typename pass_type >
@@ -3157 +3187 @@
 
         maybeAccept_impl( node->forall, *this );
-        // xxx - should PointerType visit/mutate dimension?
+        maybeAccept_impl( node->dimension, *this );
         maybeAccept_impl( node->base, *this );
 
@@ -3168 +3198 @@
 
         maybeAccept_impl( node->forall, *this );
-        // xxx - should PointerType visit/mutate dimension?
+        maybeAccept_impl( node->dimension, *this );
         maybeAccept_impl( node->base, *this );
 
@@ -3179 +3209 @@
 
         maybeMutate_impl( node->forall, *this );
-        // xxx - should PointerType visit/mutate dimension?
+        maybeMutate_impl( node->dimension, *this );
         maybeMutate_impl( node->base, *this );
 

src/Parser/DeclarationNode.cc

@@ -1076 +1076 @@
         if ( variable.tyClass != TypeDecl::NUMBER_OF_KINDS ) {
                 // otype is internally converted to dtype + otype parameters
-                static const TypeDecl::Kind kindMap[] = { TypeDecl::Dtype, TypeDecl::DStype, TypeDecl::Dtype, TypeDecl::Ftype, TypeDecl::Ttype, TypeDecl::Dtype };
+                static const TypeDecl::Kind kindMap[] = { TypeDecl::Dtype, TypeDecl::DStype, TypeDecl::Dtype, TypeDecl::Ftype, TypeDecl::Ttype, TypeDecl::Dimension };
                 static_assert( sizeof(kindMap) / sizeof(kindMap[0]) == TypeDecl::NUMBER_OF_KINDS, "DeclarationNode::build: kindMap is out of sync." );
                 assertf( variable.tyClass < sizeof(kindMap)/sizeof(kindMap[0]), "Variable's tyClass is out of bounds." );
-                TypeDecl * ret = new TypeDecl( *name, Type::StorageClasses(), nullptr, kindMap[ variable.tyClass ], variable.tyClass == TypeDecl::Otype || variable.tyClass == TypeDecl::ALtype, variable.initializer ? variable.initializer->buildType() : nullptr );
+                TypeDecl * ret = new TypeDecl( *name, Type::StorageClasses(), nullptr, kindMap[ variable.tyClass ], variable.tyClass == TypeDecl::Otype, variable.initializer ? variable.initializer->buildType() : nullptr );
                 buildList( variable.assertions, ret->get_assertions() );
                 return ret;

src/Parser/ExpressionNode.cc

@@ -509 +509 @@
 } // build_varref
 
+DimensionExpr * build_dimensionref( const string * name ) {
+        DimensionExpr * expr = new DimensionExpr( *name );
+        delete name;
+        return expr;
+} // build_varref
 // TODO: get rid of this and OperKinds and reuse code from OperatorTable
 static const char * OperName[] = {                                              // must harmonize with OperKinds

src/Parser/ParseNode.h

@@ -183 +183 @@
 
 NameExpr * build_varref( const std::string * name );
+DimensionExpr * build_dimensionref( const std::string * name );
 
 Expression * build_cast( DeclarationNode * decl_node, ExpressionNode * expr_node );

src/Parser/TypedefTable.cc

@@ -10 +10 @@
 // Created On       : Sat May 16 15:20:13 2015
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Mon Mar 15 20:56:47 2021
-// Update Count     : 260
+// Last Modified On : Wed May 19 08:30:14 2021
+// Update Count     : 262
 //
 
@@ -31 +31 @@
         switch ( kind ) {
           case IDENTIFIER: return "identifier";
+          case TYPEDIMname: return "typedim";
           case TYPEDEFname: return "typedef";
           case TYPEGENname: return "typegen";

src/Parser/parser.yy

@@ -10 +10 @@
 // Created On       : Sat Sep  1 20:22:55 2001
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Mon Apr 26 18:41:54 2021
-// Update Count     : 4990
+// Last Modified On : Wed May 19 14:20:36 2021
+// Update Count     : 5022
 //
 
@@ -287 +287 @@
 
 // names and constants: lexer differentiates between identifier and typedef names
-%token<tok> IDENTIFIER          QUOTED_IDENTIFIER       TYPEDEFname             TYPEGENname
+%token<tok> IDENTIFIER          QUOTED_IDENTIFIER       TYPEDIMname             TYPEDEFname             TYPEGENname
 %token<tok> TIMEOUT                     WOR                                     CATCH                   RECOVER                 CATCHRESUME             FIXUP           FINALLY         // CFA
 %token<tok> INTEGERconstant     CHARACTERconstant       STRINGliteral
@@ -586 +586 @@
         | quasi_keyword
                 { $$ = new ExpressionNode( build_varref( $1 ) ); }
+        | TYPEDIMname                                                                           // CFA, generic length argument
+                // { $$ = new ExpressionNode( new TypeExpr( maybeMoveBuildType( DeclarationNode::newFromTypedef( $1 ) ) ) ); }
+                // { $$ = new ExpressionNode( build_varref( $1 ) ); }
+                { $$ = new ExpressionNode( build_dimensionref( $1 ) ); }
         | tuple
         | '(' comma_expression ')'
@@ -2535 +2539 @@
         | '[' identifier_or_type_name ']'
                 {
-                        typedefTable.addToScope( *$2, TYPEDEFname, "9" );
-                        $$ = DeclarationNode::newTypeParam( TypeDecl::ALtype, $2 );
+                        typedefTable.addToScope( *$2, TYPEDIMname, "9" );
+                        $$ = DeclarationNode::newTypeParam( TypeDecl::Dimension, $2 );
                 }
         // | type_specifier identifier_parameter_declarator
@@ -2590 +2594 @@
                 { $$ = new ExpressionNode( new TypeExpr( maybeMoveBuildType( $1 ) ) ); }
         | assignment_expression
-                { SemanticError( yylloc, toString("Expression generic parameters are currently unimplemented: ", $1->build()) ); $$ = nullptr; }
         | type_list ',' type
                 { $$ = (ExpressionNode *)($1->set_last( new ExpressionNode( new TypeExpr( maybeMoveBuildType( $3 ) ) ) )); }
         | type_list ',' assignment_expression
-                { SemanticError( yylloc, toString("Expression generic parameters are currently unimplemented: ", $3->build()) ); $$ = nullptr; }
-                // { $$ = (ExpressionNode *)( $1->set_last( $3 )); }
+                { $$ = (ExpressionNode *)( $1->set_last( $3 )); }
         ;
 

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;
         }
 

src/SynTree/Declaration.h

@@ -201 +201 @@
         typedef NamedTypeDecl Parent;
   public:
-        enum Kind { Dtype, DStype, Otype, Ftype, Ttype, ALtype, NUMBER_OF_KINDS };
+        enum Kind { Dtype, DStype, Otype, Ftype, Ttype, Dimension, NUMBER_OF_KINDS };
 
         Kind kind;

src/SynTree/Expression.h

@@ -587 +587 @@
 };
 
+/// DimensionExpr represents a type-system provided value used in an expression ( forrall([N]) ... N + 1 )
+class DimensionExpr : public Expression {
+  public:
+        std::string name;
+
+        DimensionExpr( std::string name );
+        DimensionExpr( const DimensionExpr & other );
+        virtual ~DimensionExpr();
+
+        const std::string & get_name() const { return name; }
+        void set_name( std::string newValue ) { name = newValue; }
+
+        virtual DimensionExpr * clone() const override { return new DimensionExpr( * this ); }
+        virtual void accept( Visitor & v ) override { v.visit( this ); }
+        virtual void accept( Visitor & v ) const override { v.visit( this ); }
+        virtual Expression * acceptMutator( Mutator & m ) override { return m.mutate( this ); }
+        virtual void print( std::ostream & os, Indenter indent = {} ) const override;
+};
+
 /// AsmExpr represents a GCC 'asm constraint operand' used in an asm statement: [output] "=f" (result)
 class AsmExpr : public Expression {

src/SynTree/Mutator.h

@@ -80 +80 @@
         virtual Expression * mutate( CommaExpr * commaExpr ) = 0;
         virtual Expression * mutate( TypeExpr * typeExpr ) = 0;
+        virtual Expression * mutate( DimensionExpr * dimensionExpr ) = 0;
         virtual Expression * mutate( AsmExpr * asmExpr ) = 0;
         virtual Expression * mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) = 0;

src/SynTree/SynTree.h

@@ -85 +85 @@
 class CommaExpr;
 class TypeExpr;
+class DimensionExpr;
 class AsmExpr;
 class ImplicitCopyCtorExpr;

src/SynTree/TypeDecl.cc

@@ -33 +33 @@
 
 const char * TypeDecl::typeString() const {
-        static const char * kindNames[] = { "sized data type", "sized data type", "sized object type", "sized function type", "sized tuple type", "sized array length type" };
+        static const char * kindNames[] = { "sized data type", "sized data type", "sized object type", "sized function type", "sized tuple type", "sized length value" };
         static_assert( sizeof(kindNames) / sizeof(kindNames[0]) == TypeDecl::NUMBER_OF_KINDS, "typeString: kindNames is out of sync." );
         assertf( kind < TypeDecl::NUMBER_OF_KINDS, "TypeDecl kind is out of bounds." );

src/SynTree/TypeExpr.cc

@@ -35 +35 @@
 }
 
+DimensionExpr::DimensionExpr( std::string name ) : Expression(), name(name) {
+        assertf(name != "0", "Zero is not a valid name");
+        assertf(name != "1", "One is not a valid name");
+}
+
+DimensionExpr::DimensionExpr( const DimensionExpr & other ) : Expression( other ), name( other.name ) {
+}
+
+DimensionExpr::~DimensionExpr() {}
+
+void DimensionExpr::print( std::ostream & os, Indenter indent ) const {
+        os << "Type-Sys Value: " << get_name();
+        Expression::print( os, indent );
+}
 // Local Variables: //
 // tab-width: 4 //

src/SynTree/Visitor.h

@@ -135 +135 @@
         virtual void visit( TypeExpr * node ) { visit( const_cast<const TypeExpr *>(node) ); }
         virtual void visit( const TypeExpr * typeExpr ) = 0;
+        virtual void visit( DimensionExpr * node ) { visit( const_cast<const DimensionExpr *>(node) ); }
+        virtual void visit( const DimensionExpr * typeExpr ) = 0;
         virtual void visit( AsmExpr * node ) { visit( const_cast<const AsmExpr *>(node) ); }
         virtual void visit( const AsmExpr * asmExpr ) = 0;

tests/array-container/array-basic.cfa

@@ -61 +61 @@
 forall( [Nw], [Nx], [Ny], [Nz] )
 void fillHelloData( array( float, Nw, Nx, Ny, Nz ) & wxyz ) {
-    for (w; z(Nw))
-    for (x; z(Nx))
-    for (y; z(Ny))
-    for (z; z(Nz))
+    for (w; Nw)
+    for (x; Nx)
+    for (y; Ny)
+    for (z; Nz)
         wxyz[w][x][y][z] = getMagicNumber(w, x, y, z);
 }
 
-forall( [Zn]
+forall( [N]
       , S & | sized(S)
       )
-float total1d_low( arpk(Zn, S, float, float ) & a ) {
+float total1d_low( arpk(N, S, float, float ) & a ) {
     float total = 0.0f;
-    for (i; z(Zn))
+    for (i; N)
         total += a[i];
     return total;
@@ -98 +98 @@
 
     expect = 0;
-    for (i; z(Nw))
+    for (i; Nw)
         expect += getMagicNumber( i, slice_ix, slice_ix, slice_ix );
     printf("expect Ws             = %f\n", expect);
@@ -117 +117 @@
 
     expect = 0;
-    for (i; z(Nx))
+    for (i; Nx)
         expect += getMagicNumber( slice_ix, i, slice_ix, slice_ix );
     printf("expect Xs             = %f\n", expect);

tests/array-container/array-md-sbscr-cases.cfa

@@ -20 +20 @@
 forall( [Nw], [Nx], [Ny], [Nz] )
 void fillHelloData( array( float, Nw, Nx, Ny, Nz ) & wxyz ) {
-    for (w; z(Nw))
-    for (x; z(Nx))
-    for (y; z(Ny))
-    for (z; z(Nz))
+    for (w; Nw)
+    for (x; Nx)
+    for (y; Ny)
+    for (z; Nz)
         wxyz[w][x][y][z] = getMagicNumber(w, x, y, z);
 }
@@ -246 +246 @@
     assert(( wxyz[[2,  3,  4,  5]] == valExpected ));
 
-    for ( i; z(Nw) ) {
+    for ( i; Nw ) {
         assert(( wxyz[[ i, 3, 4, 5 ]] == getMagicNumber(i, 3, 4, 5) ));
     }
 
-    for ( i; z(Nx) ) {
+    for ( i; Nx ) {
         assert(( wxyz[[ 2, i, 4, 5 ]] == getMagicNumber(2, i, 4, 5) ));
     }
 
-    for ( i; z(Ny) ) {
+    for ( i; Ny ) {
         assert(( wxyz[[ 2, 3, i, 5 ]] == getMagicNumber(2, 3, i, 5) ));
     }
 
-    for ( i; z(Nz) ) {
+    for ( i; Nz ) {
         assert(( wxyz[[ 2, 3, 4, i ]] == getMagicNumber(2, 3, 4, i) ));
     }
 
-    for ( i; z(Nw) ) {
+    for ( i; Nw ) {
         assert(( wxyz[[ i, all, 4, 5 ]][3] == getMagicNumber(i, 3, 4, 5) ));
     }
 
-    for ( i; z(Nw) ) {
+    for ( i; Nw ) {
         assert(( wxyz[[ all, 3, 4, 5 ]][i] == getMagicNumber(i, 3, 4, 5) ));
     }