dvander@195: /* vim: set ts=4 sw=4 tw=99 et:
dvander@195:  *
dvander@195:  * Copyright (C) 2012 David Anderson
dvander@195:  *
dvander@195:  * This file is part of JITCraft.
dvander@195:  *
dvander@195:  * JITCraft is free software: you can redistribute it and/or modify it under
dvander@195:  * the terms of the GNU General Public License as published by the Free
dvander@195:  * Software Foundation, either version 3 of the License, or (at your option)
dvander@195:  * any later version.
dvander@195:  * 
dvander@195:  * Foobar is distributed in the hope that it will be useful, but WITHOUT ANY
dvander@195:  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
dvander@195:  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
dvander@195:  *
dvander@195:  * You should have received a copy of the GNU General Public License along with
dvander@195:  * JITCraft. If not, see http://www.gnu.org/licenses/.
dvander@195:  */
dvander@195: #ifndef _include_semantic_analysis_h_
dvander@195: #define _include_semantic_analysis_h_
dvander@195: 
dvander@195: #include <assert.h>
dvander@195: #include "AST.h"
dvander@195: #include "../Types.h"
dvander@195: 
dvander@195: namespace ke {
dvander@195: 
dvander@195: class Box;
dvander@195: 
dvander@195: class SemanticAnalysis : public AstVisitor
dvander@195: {
dvander@195:     Zone *zone_;
dvander@195:     CompileContext &cc_;
dvander@195:     ParseTree *tree_;
dvander@195:     Scope *scope_;
dvander@195:     NamedFunction *function_;
dvander@195: 
dvander@195:     enum ReturnStatus
dvander@195:     {
dvander@195:         Returns_Never,
dvander@195:         Returns_Sometimes,
dvander@195:         Returns_Always
dvander@195:     };
dvander@195: 
dvander@195:     // Tuple that describes whether a path terminates control flow, and
dvander@195:     // if it is guaranteed to end in a return.
dvander@195:     class ControlStatus
dvander@195:     {
dvander@195:         bool terminates_;
dvander@195:         ReturnStatus returns_;
dvander@195: 
dvander@195:       public:
dvander@195:         ControlStatus(bool terminates, ReturnStatus returns)
dvander@195:           : terminates_(terminates),
dvander@195:             returns_(returns)
dvander@195:         {
dvander@195:         }
dvander@195: 
dvander@195:         bool terminates() const {
dvander@195:             return terminates_;
dvander@195:         }
dvander@195:         ReturnStatus returns() const {
dvander@195:             return returns_;
dvander@195:         }
dvander@195:     };
dvander@195: 
dvander@195:     // Used to keep track of terminating control flow and return statements
dvander@195:     // inside control structures.
dvander@195:     class ControlScope
dvander@195:     {
dvander@195:         ReturnStatus returns_;
dvander@195:         ControlScope **prevp_;
dvander@195:         ControlScope *prev_;
dvander@195:         bool terminates_;
dvander@195: 
dvander@195:       public:
dvander@195:         ControlScope(ControlScope **prev)
dvander@195:           : returns_(Returns_Never),
dvander@195:             prevp_(prev),
dvander@195:             prev_(*prev),
dvander@195:             terminates_(false)
dvander@195:         {
dvander@195:             *prevp_ = this;
dvander@195:         }
dvander@195: 
dvander@195:         ControlStatus status() const {
dvander@195:             return ControlStatus(terminates_, returns_);
dvander@195:         }
dvander@195: 
dvander@195:         // We allow multiple terminators, but only the first one takes effect.
dvander@195:         // For example, |break; continue;| is legal but the continue is
dvander@195:         // unreachable.
dvander@195:         void returns(ReturnStatus status) {
dvander@195:             if (terminates_)
dvander@195:                 return;
dvander@195:             if (status > returns_)
dvander@195:                 returns_ = status;
dvander@195:         }
dvander@195:         void terminate(ReturnStatus status) {
dvander@195:             if (terminates_)
dvander@195:                 return;
dvander@195:             terminates_ = true;
dvander@195:             returns_ = status;
dvander@195:         }
dvander@195:         void merge(const ControlStatus &left, const ControlStatus &right);
dvander@195:         void inherit(const ControlStatus &other);
dvander@195: 
dvander@195:         ~ControlScope()
dvander@195:         {
dvander@195:             *prevp_ = prev_;
dvander@195:         }
dvander@195:     };
dvander@195: 
dvander@195:     class LoopScope
dvander@195:     {
dvander@195:         LoopScope **prevp_;
dvander@195:         LoopScope *prev_;
dvander@195:         unsigned breaks_;
dvander@195:         unsigned continues_;
dvander@195: 
dvander@195:       public:
dvander@195:         LoopScope(LoopScope **prev)
dvander@195:           : prevp_(prev),
dvander@195:             prev_(*prev),
dvander@195:             breaks_(0),
dvander@195:             continues_(0)
dvander@195:         {
dvander@195:             *prevp_ = this;
dvander@195:         }
dvander@195: 
dvander@195:         ~LoopScope()
dvander@195:         {
dvander@195:             *prevp_ = prev_;
dvander@195:         }
dvander@195: 
dvander@195:         void addBreak() {
dvander@195:             breaks_++;
dvander@195:         }
dvander@195:         void addContinue() {
dvander@195:             continues_++;
dvander@195:         }
dvander@195:         unsigned breaks() const {
dvander@195:             return breaks_;
dvander@195:         }
dvander@195:         unsigned continues() const {
dvander@195:             return continues_;
dvander@195:         }
dvander@195:     };
dvander@195: 
dvander@195:     ControlScope *control_;
dvander@195:     LoopScope *loop_;
dvander@195: 
dvander@195:   private:
dvander@195:     bool canTest(AstNode *node, Handle<Type> type);
dvander@195:     void typeMismatch(const SourcePosition &pos, Handle<Type> actual, Handle<Type> given);
dvander@195:     void unaryTypeError(AstNode *node, TokenKind token, Handle<Type> type);
dvander@195:     void binaryTypeError(AstNode *node, TokenKind token, Handle<Type> left, Handle<Type> right);
dvander@195:     Type *typeCheckBinary(AstNode *node, TokenKind token, Handle<Type> left, Handle<Type> right);
dvander@195: 
dvander@195:     Type *bindType(const SourcePosition &pos, BoundName *name);
dvander@195: 
dvander@195:     // These check if one type is compatible with another type, for various
dvander@195:     // purposes, like:
dvander@195:     //      return (expr) matches function return type
dvander@195:     //      call(a, b)    matches expected arg type
dvander@195:     //      a = b         matches declared type
dvander@195:     //
dvander@195:     bool typeCheckArrayAssignment(const SourcePosition &pos, Handle<Type> given, Handle<Type> actual, bool forAssign);
dvander@195:     bool typeCheckAssignment(const SourcePosition &pos, Handle<Type> given, Handle<Type> actual, bool forAssign);
dvander@195:     bool typeCheckParameter(AstNode *node, Handle<Type> given, Handle<Type> actual);
dvander@195: 
dvander@195:     Type *visitForLoad(Expression *expression);
dvander@195:     bool preanalyze(FunctionStatement *node);
dvander@195:     Type *visitForLValue(Expression *expression);
dvander@195:     Type *visitAndApplyType(Expression *expression);
dvander@195:     ControlStatus visitForControl(Statement *statement);
dvander@195: 
dvander@195:     bool evaluateDimensions(ExpressionList *exprs, int dims[MAX_ARRAY_DEPTH]);
dvander@195:     bool inferFixedArrayLiteral(ArrayLiteral *literal,
dvander@195:                                 Handle<Type> type,
dvander@195:                                 int dims[MAX_ARRAY_DEPTH],
dvander@195:                                 unsigned dimcount,
dvander@195:                                 unsigned level);
dvander@195: 
dvander@195:     // Builds an array type used for parameters, returns, or field entries.
dvander@195:     Type *buildArrayType(Handle<Type> type, ExpressionList *dimensions, bool isConst);
dvander@195: 
dvander@195:     Box *evaluateDefaultParameter(Handle<Type> type, Parameter *parameter);
dvander@195:     bool checkArgumentCount(Handle<Type> type, unsigned actual);
dvander@195:     bool buildFunctionArgs(AstNode *node, TokenKind kind, const FunctionSignature &sig,
dvander@195:                            FixedArray **args, FixedArray **defaults);
dvander@195: 
dvander@195:     void markCallResultUsed(CallExpression *call);
dvander@195: 
dvander@195:     bool determineLiveFunctions();
dvander@195: 
dvander@195:   public:
dvander@195:     SemanticAnalysis(Zone *zone, CompileContext &cc, ParseTree *tree);
dvander@195:     bool analyze();
dvander@195: 
dvander@195:   public:
dvander@195:     void visit(NameProxy *name);
dvander@195:     void visit(Assignment *node);
dvander@195:     void visit(BinaryExpression *node);
dvander@195:     void visit(ReturnStatement *node);
dvander@195:     void visit(ForStatement *node);
dvander@195:     void visit(BlockStatement *node);
dvander@195:     void visit(VariableDeclaration *node);
dvander@195:     void visit(IntegerLiteral *node);
dvander@195:     void visit(ExpressionStatement *node);
dvander@195:     void visit(FunctionStatement *node);
dvander@195:     void visit(CallExpression *node);
dvander@195:     void visit(IfStatement *node);
dvander@195:     void visit(IndexExpression *node);
dvander@195:     void visit(EnumStatement *node);
dvander@195:     void visit(FloatLiteral *node);
dvander@195:     void visit(WhileStatement *node);
dvander@195:     void visit(BreakStatement *node);
dvander@195:     void visit(ContinueStatement *node);
dvander@195:     void visit(StringLiteral *node);
dvander@195:     void visit(IncDecExpression *node);
dvander@195:     void visit(UnaryExpression *node);
dvander@195:     void visit(TernaryExpression *node);
dvander@195:     void visit(BooleanLiteral *node);
dvander@195:     void visit(StructureStatement *node);
dvander@195:     void visit(FieldExpression *node);
dvander@195:     void visit(SwitchStatement *node);
dvander@195:     void visit(FunctionTypeStatement *node);
dvander@195:     void visit(ArrayLiteral *node);
dvander@195:     void visit(ImportStatement *node);
dvander@195: };
dvander@195: 
dvander@195: const char *GetTypeName(Type *type);
dvander@195: 
dvander@195: } // namespace ke
dvander@195: 
dvander@195: #endif // _include_semantic_analysis_h_