使用flex和bison实现的sql引擎解析(二)

接下来是对词的语法识别

%{
#include 
#include 
#include 
#include 
#include 
char * parsetreeroot=NULL;
extern "C" int yylex();
extern "C" int yyparse();
extern "C" void yyerror(const char *s, ...);
char globalInputText[10000];
int globalReadOffset;
int readInputForLexer( char *buffer, int *numBytesRead, int maxBytesToRead );
char * mystrcat(char *s1,char *s2)
{
	char *p1=(char *)malloc(strlen(s1)+strlen(s2)+1);
	strcpy(p1,s1);
	strcat(p1,s2);
	return p1;
}
%}
%locations
%union {
	int intval;		
	double floatval;	
	char *strval;
	int subtok;
}
%token  NAME
%token  STRING
%token  INTNUM
%token  BOOL
%token  APPROXNUM
%token  USERVAR

%type  stmt_root  create_stmt para_list definition  data_type pro_block pro_parameters declare_list set_list 
%type  assign_var  pro_body pro_stmt_list sql_stmt expr



%right ASSIGN
%left OR
%left XOR
%left ANDOP

%left NOT '!'
%left BETWEEN
%left  COMPARISON /* = <> < > <= >= <=> */
%left '|'
%left '&'
%left  SHIFT /* << >> */
%left '+' '-'
%left '*' '/' '%' MOD
%left '^'

%token CREATE
%token PROCEDURE
%token PRONAME
%token DECLARE
%token SET
%token BEGINT
%token END
%token SQL

%token INT





%token VARCHAR
%token DATE
%token TIME
%token DOUBLE

%token IF
%token NOT
%token EXISTS
%token THEN
%token ELSE
%token ENDIF
%token FOR
%token WHEN
%token WHILE
%start stmt_root
%%

stmt_root: create_stmt pro_block { $$=mystrcat($1,$2); parsetreeroot=$$;}
;
create_stmt: CREATE PROCEDURE  NAME '(' para_list ')' 
		{
			char *temp=mystrcat("create procedure ",$3);
			temp=mystrcat(temp,"(");
			temp=mystrcat(temp,$5);
			$$=mystrcat(temp,")(create)\n");
		}
;
/*
opt_if_not_exists:	      { $$ = 0; } 
   | IF NOT EXISTS            { $$ = 1; } 
   ;
*/
para_list: definition { $$=$1; }
|definition ',' para_list 
		{	
			
			char *temp=mystrcat($1,",");
			$$=mystrcat(temp,$3); 
		}
;
definition: USERVAR data_type 
		{	
			
			char *temp=mystrcat($1," ");
			$$=mystrcat(temp,$2);
			
		}
;

data_type:
   DATE 					{$$="date"; }
   | TIME					{$$="time"; }
   | VARCHAR '(' INTNUM ')' 			{$$="varchar"; }
   | INT 					{$$="int"; }
   | DOUBLE 					{$$="double"; }	
   ;

pro_block: BEGINT pro_parameters pro_body END 
		{ 
			char *temp=mystrcat("begin\n",$2);
			temp=mystrcat(temp,"");
			temp=mystrcat(temp,$3);
			$$=mystrcat(temp,"end");
			//printf("pro_body %s\n",$3);
		}
;

pro_parameters: declare_list ';' { $$=mystrcat($1,";(declare)\n");}
|pro_parameters  declare_list ';' 
		{ 
			char *temp=mystrcat($1,$2);
			$$=mystrcat(temp,";(declare)\n");
		}
|pro_parameters  set_list ';' 
		{
	 		char *temp=mystrcat($1,$2);
			$$=mystrcat(temp,";(set)\n");
		}
;

declare_list:
|DECLARE definition 
		{
			$$=mystrcat("declare ",$2);
		}
|declare_list ',' definition 
		{ 
			char *temp=mystrcat($1,",");
			$$=mystrcat(temp,$3); 
		}
;

set_list:
|SET assign_var 
		{
			$$=mystrcat("set ",