linx

cmparser.y

%{ #include <stdio.h> #include <string.h> #include <stdlib.h> #include "ast.h" #include "symbolTable.h" #include "util.h" /* other external function prototypes */ extern int yylex(); extern int initLex(int , char **); extern AstNodePtr new_Node(NodeKind kind); /* external global variables */ extern int yydebug; extern int yylineno; extern SymbolTableStackEntryPtr symbolStackTop; extern int scopeDepth; /* function prototypes */ void yyerror(const char *); /* global variables */ AstNodePtr program; FILE *outfile; %} /* YYSTYPE */ %union { AstNodePtr nodePtr; int iVal; char *cVal; Type *type; } /* terminals */ %token TOK_ELSE TOK_IF TOK_RETURN TOK_VOID TOK_INT TOK_WHILE %token TOK_PLUS TOK_MINUS TOK_MULT TOK_DIV TOK_LT TOK_LE TOK_GT TOK_GE TOK_EQ TOK_NE TOK_ASSIGN TOK_SEMI TOK_COMMA %token TOK_LPAREN TOK_RPAREN TOK_LSQ TOK_RSQ TOK_LBRACE TOK_RBRACE TOK_ERROR %token <cVal> TOK_ID %token <iVal> TOK_NUM %type <nodePtr> Declarations Functions Fun_Declaration %type <type> Type_Specifier %type <nodePtr> Compound_Stmt Statements Statement %type <nodePtr> Expr_Statement If_Else_Statement Selection_Stmt Iteration_Stmt Return_Stmt %type <nodePtr> Expression Simple_Expression Additive_Expression Factor Var Call Term %type <nodePtr> Args Args_List %type <nodePtr> Params Param_List Param /* associativity and precedence */ %nonassoc TOK_IF %nonassoc TOK_ELSE %right TOK_ASSIGN %left TOK_EQ TOK_NE %nonassoc TOK_LT TOK_GT TOK_LE TOK_GE %left TOK_PLUS TOK_SUB %left TOK_MULT TOK_DIV %nonassoc error %% Start : Declarations {} ; Declarations : Functions { program = $1;} | Var_Declaration Declarations { } ; Functions : Fun_Declaration { $$ = $1 } | Fun_Declaration Functions { $1->sibling = $2; $$ = $1 } ; Var_Declaration : Type_Specifier TOK_ID TOK_SEMI { if ($1->kind != INT){ yyerror("non-int variable declared\n"); yyerror($2); } ElementPtr symElement = symLookup($2); if(!symElement || scopeDepth != symElement->scope) symInsert($2,$1,yylineno); else { yyerror("Redeclaration of variable"); yyerror($2); free($1); } } | Type_Specifier TOK_ID TOK_LSQ TOK_NUM TOK_RSQ TOK_SEMI { if ($1->kind != INT){ yyerror("non-int variable declared\n"); yyerror($2); } ElementPtr symElement = symLookup($2); if(!symElement || scopeDepth != symElement->scope) { /* reuse Type for storing dimension */ $1->kind = ARRAY; $1->dimension = $4; $1->function = NULL; symInsert($2,$1,yylineno); } else { yyerror("Redeclaration of variable"); yyerror($2); free($1); } } ; Fun_Declaration : Type_Specifier TOK_ID TOK_LPAREN { $<nodePtr>$ = new_Node(METHOD); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->nType = $1; ElementPtr symElement = symLookup($2); if(!symElement || scopeDepth != symElement->scope) { $<nodePtr>$->nSymbolPtr = symInsert($2,$1,yylineno); $<nodePtr>$->nSymbolPtr->stype->function = (Type*) malloc(sizeof(Type)); $<nodePtr>$->nSymbolPtr->stype->function->kind = $1->kind; $<nodePtr>$->nSymbolPtr->snode = $<nodePtr>$; $1->kind = FUNCTION; enterScope(); } else { yyerror("Redeclaration of function"); yyerror($2); free($1); } } Params TOK_RPAREN { $<nodePtr>4->children[0] = $5; } Compound_Stmt { $<nodePtr>4->children[1] = $8; $$ = $<nodePtr>4; leaveScope(); } ; Params : Param_List {$$ = $1} | TOK_VOID {$$=NULL;} ; Param_List : Param_List TOK_COMMA Param { $<nodePtr>$ = $1; while($<nodePtr>$->sibling) $<nodePtr>$ = $<nodePtr>$->sibling; $<nodePtr>$->sibling = $3; $3->sibling = NULL; $$ = $1; } | Param { $1->sibling = NULL; $$ = $1; } ; Param : Type_Specifier TOK_ID { ElementPtr symElement = symLookup($2); if(!symElement || scopeDepth != symElement->scope) { $$ = new_Node(FORMALVAR); $$->nLinenumber = yylineno; if ($1->kind != INT){ yyerror("non-int variable declared\n"); } else{ $$->nSymbolPtr = symInsert($2,$1,yylineno); $$->nType = $1; } } else { yyerror("Redeclaration of variable"); yyerror($2); free($1); } } | Type_Specifier TOK_ID TOK_LSQ TOK_RSQ { ElementPtr symElement = symLookup($2); if(!symElement || scopeDepth != symElement->scope) { Type *typ; if ($1->kind != INT){ yyerror("non-int array declared\n"); } typ = new_type(ARRAY); $$ = new_Node(FORMALVAR); $$->nLinenumber = yylineno; $$->nSymbolPtr = symInsert($2,typ,yylineno); $$->nType = typ; free($1); } else { yyerror("Redeclaration of variable\n"); yyerror($2); free($1); } } ; Type_Specifier : TOK_INT { $$ = (Type*) new_type(INT); } | TOK_VOID { $$ = (Type*) new_type(VOID); } ; Compound_Stmt : TOK_LBRACE { enterScope(); $<nodePtr>$ = new_StmtNode(COMPOUND_STMT); $<nodePtr>$->nSymbolTabPtr = symbolStackTop->symbolTablePtr; $<nodePtr>$->nLinenumber = yylineno; } Statements { $<nodePtr>2->children[0] = $3; } // shud point to first statement TOK_RBRACE { leaveScope(); $$ = $<nodePtr>2; } | TOK_LBRACE { enterScope(); $<nodePtr>$ = new_StmtNode(COMPOUND_STMT); $<nodePtr>$->nSymbolTabPtr = symbolStackTop->symbolTablePtr; $<nodePtr>$->nLinenumber = yylineno; } Local_Declarations Statements { $<nodePtr>2->children[0] = $4;} // shud point to first statement TOK_RBRACE { leaveScope(); $$ = $<nodePtr>2; } ; Local_Declarations : Var_Declaration Local_Declarations {} | Var_Declaration {} ; Statements : Statement Statements { $1->sibling = $2; $$ = $1; } | {$$=NULL} ; Statement : Expr_Statement { $$ = $1; } | Compound_Stmt { $$ = $1; } | Selection_Stmt { $$ = $1; } | Iteration_Stmt { $$ = $1; } | Return_Stmt { $$ = $1; } ; Expr_Statement : Expression TOK_SEMI { $$ = new_StmtNode(EXPRESSION_STMT); $$->nLinenumber = yylineno; $$->children[0] = $1; } | TOK_SEMI { $$ = new_StmtNode(EXPRESSION_STMT) ; $$->nLinenumber = yylineno; $$->children[0] = NULL; } ; Selection_Stmt : If_Else_Statement %prec TOK_IF { $$ = $1; } | If_Else_Statement TOK_ELSE Statement { $$ = $1; $$->children[2]= $3; } ; If_Else_Statement : TOK_IF TOK_LPAREN Expression { $<nodePtr>$ = new_StmtNode(IF_THEN_ELSE_STMT); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $3; } TOK_RPAREN Statement { $<nodePtr>4->children[1] = $6; $$ = $<nodePtr>4; } ; Iteration_Stmt : TOK_WHILE TOK_LPAREN Expression { $<nodePtr>$ = new_StmtNode(WHILE_STMT); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $3; } TOK_RPAREN Statement { $<nodePtr>4->children[1] = $6; $$ = $<nodePtr>4; $<nodePtr>$->nLinenumber = yylineno; } ; Return_Stmt : TOK_RETURN Expression TOK_SEMI { $$ = new_StmtNode(RETURN_STMT); $$->nLinenumber = yylineno; $$->children[0] = $2; } | TOK_RETURN TOK_SEMI { $$ = new_StmtNode(RETURN_STMT); $$->nLinenumber = yylineno; $$->children[0] = NULL; } ; Expression : Var TOK_ASSIGN { $<nodePtr>$ = new_ExprNode(ASSI_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Expression { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Simple_Expression { $$ = $1; } ; Var : TOK_ID { $$ = new_ExprNode(VAR_EXP); $$->nLinenumber = yylineno; $$->nSymbolPtr = symLookup($1); if(!$$->nSymbolPtr) { yyerror("Variable must be declared before use"); yyerror($1); free($$); } } | TOK_ID TOK_LSQ Expression TOK_RSQ { $$ = new_ExprNode(ARRAY_EXP); $$->nLinenumber = yylineno; $$->nSymbolPtr = symLookup($1); if(!$$->nSymbolPtr) { yyerror("Variable must be declared before use"); yyerror($1); free($$); } else $$->children[0] = $3; } ; Simple_Expression : Additive_Expression TOK_GT { $<nodePtr>$ = new_ExprNode(GT_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Additive_Expression { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Additive_Expression TOK_LT { $<nodePtr>$ = new_ExprNode(LT_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Additive_Expression { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Additive_Expression TOK_GE { $<nodePtr>$ = new_ExprNode(GE_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Additive_Expression { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Additive_Expression TOK_LE { $<nodePtr>$ = new_ExprNode(LE_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Additive_Expression { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Additive_Expression TOK_EQ { $<nodePtr>$ = new_ExprNode(EQ_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Additive_Expression { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Additive_Expression TOK_NE { $<nodePtr>$ = new_ExprNode(NE_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Additive_Expression { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Additive_Expression { $$ = $1 } ; Additive_Expression : Additive_Expression TOK_PLUS { $<nodePtr>$ = new_ExprNode(ADD_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Term { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Additive_Expression TOK_MINUS { $<nodePtr>$ = new_ExprNode(SUB_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Term { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Term { $$ = $1; } ; Term : Term TOK_MULT { $<nodePtr>$ = new_ExprNode(MULT_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Factor { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Term TOK_DIV { $<nodePtr>$ = new_ExprNode(DIV_EXP); $<nodePtr>$->nLinenumber = yylineno; $<nodePtr>$->children[0] = $1; } Factor { $<nodePtr>3->children[1] = $4; $$ = $<nodePtr>3; } | Factor { $$ = $1; } ; Factor : TOK_LPAREN Expression TOK_RPAREN { $$ = $2; } | Var { $$ = $1 } | Call { $$ = $1 } | TOK_NUM { $$ = new_ExprNode(CONST_EXP); $$->nLinenumber = yylineno; $$->nValue = $1; } ; Call : TOK_ID TOK_LPAREN Args TOK_RPAREN { $$= new_ExprNode(CALL_EXP); $$->nLinenumber = yylineno; $$->nSymbolPtr = symLookup($1); if(!$$->nSymbolPtr) { printf("function %s not found, forward reference\n", $1); $$->fname = strdup($1); } $$->children[0] = $3; } ; Args : Args_List {$$=$1;} | { $$ = NULL; } ; Args_List : Args_List TOK_COMMA Expression { $<nodePtr>$ = $1; while($<nodePtr>$->sibling) $<nodePtr>$ = $<nodePtr>$->sibling; $<nodePtr>$->sibling = $3; $3->sibling = NULL; $$ = $1; } | Expression { $1->sibling = NULL; $$ = $1; } ; %% void yyerror (char const *s) { fprintf (stderr, "Error at line %d: %s\n", yylineno, s); exit(1); } int main(int argc, char **argv){ initLex(argc,argv); #ifdef YYLLEXER while (gettok() !=0) ; //gettok returns 0 on EOF return; #else initSymbolTable(); yyparse(); #endif }