grammar.y

利用语言编写的有限元分析软件

 *  ---------------------- */

quantity:  NUMBER                           { $$ = Code(Push_Dimensionless); 
                                              Code3(Push_Constant, (Inst)$1, Dimension_Eval); }
        |  NUMBER dimensions                { Code3(Push_Constant, (Inst)$1, Dimension_Eval); $$ = $2;}
        |  VAR                              { $$ =  Code3(Push_Variable, (Inst)$1,  Variable_Eval); }
        |  BLTIN_QUANTITY '(' ')'           { Code2( Bltin_Quantity, (Inst)$1->u.quantityptr); }
        |  BLTIN1_QUANTITY '(' quantity ')' { Code2( Bltin1_Quantity, (Inst)$1->u.quantityptr); }
        |  BLTIN2_QUANTITY '(' quantity ','
                               quantity ')' { Code2( Bltin2_Quantity, (Inst)$1->u.quantityptr); }
        |  BLTIN3_QUANTITY '(' matrix   ')' { Code2( Bltin3_Quantity, (Inst)$1->u.quantityptr); }
        |  BLTINVar_QUANTITY '('quantity_row ')'
                                            { Code2(Push_Variable, (Inst)$3);
                                              $$ = Code2(BltinVar_Quantity, (Inst)$1->u.quantityptr); }
	|  '-' quantity  %prec  UNARYMINUS  { Code(Quantity_Negate); }
	|  '+' quantity  %prec  UNARYPLUS   { Code(Quantity_Affirm); }
	|  m_to_quantity	            { $$ = $1; }
        |  quantity_assign                  { ;} 
        |  conditional_quantity             { $$ = $1;} 
        |  '(' quantity ')'                 { $$ = $2; }
        |  quantity '+' quantity            { Code(Quantity_Add); }
        |  quantity '-' quantity            { Code(Quantity_Sub); }
        |  quantity '*' quantity            { Code(Quantity_Mul); }
        |  quantity '/' quantity            { Code(Quantity_Div); }
        |  quantity '^' quantity            { Code(Quantity_Power); }
        ;

conditional_quantity:  quantity GT  quantity  { Code(Quantity_Gt);   }
	            |  quantity GE  quantity  { Code(Quantity_Ge);   }
	            |  quantity LT  quantity  { Code(Quantity_Lt);   }
	            |  quantity LE  quantity  { Code(Quantity_Le);   }
	            |  quantity EQ  quantity  { Code(Quantity_Eq);   }
	            |  quantity NE  quantity  { Code(Quantity_Ne);   }
	            |  quantity AND quantity  { Code(Quantity_And);  }
	            |  quantity OR  quantity  { Code(Quantity_Or);   }
	            |  NOT quantity           { Code(Quantity_Not); $$ = $2; }
	            ;	

quantity_assign : VAR '=' quantity  {  Code2( Push_Variable, (Inst)$1);
                                       Code( Assign_Quantity); $$ = $3; }
                | MATX '[' quantity ']' '[' quantity ']' '=' quantity { 
                                       Code2( Push_Matrix, (Inst)$1);
                                       Code( Assign_Matrix_Item ); $$ = $9;}
	        ;	

m_to_quantity : MATX '[' quantity ']' '[' quantity ']' {
                                       Code3( Push_Matrix, (Inst)$1, Matrix_Eval);
                                        Code( Quantity_Extract); }
              ;

dimensions: DIMENSION                 { $$ = Code2( Push_Dimension, (Inst)$1); }
	  |  '(' dimensions ')'       {  $$ = $2; }
	  | dimensions '*' dimensions {  Code( Dimension_Mult ); }
	  | dimensions '/' dimensions {  Code( Dimension_Div); }
	  | dimensions '^' quantity   {  $$ = $1; Code( Dimension_Power); }
	  ;	
%%


/*
 *  ------------------------------
 *  Lexical Analysis
 *  ------------------------------
 */

#include <stdio.h>       
#include <ctype.h>		
#include <signal.h>
#include <setjmp.h>

char   *progname;
extern int      lineno;
extern char    *infile;
extern FILE       *fin;
extern FILE      *finp;
extern jmp_buf   begin;

int indef, c;

int  backslash();
int  follow();
int  yyerror();
void warning();
void EXECUTION_ERROR();
void fpecatch();
void Defn_Only();

yylex()
{
int finished;

  /* [a] : Eat blank space, tab, and newline input -- read comment statements */
       
     while((c = fgetc(fin)) == ' ' || c == '\t' || c == '\n' || c == '/') {

          if(c == '\n') 
             lineno++;

          if(fin == stdin && finp != stdin) {
             if(c == '\n') {
                printf("ALADDIN : ");
                fflush(stdout);
             }
             fputc(c, finp);
          }

          if(c == '/') {
             if(follow('*', TRUE, FALSE) == TRUE) {
                c = fgetc(fin);
                finished = FALSE;
                while(finished == FALSE) {
                    c = fgetc(fin);

                    if(c == '\n') 
                       lineno++;

                    if(c == EOF) 
                       FatalError("ERROR >> ... file ended with unbalanced comment !!\n",
                                  (char *)NULL);
                    if((c == '*') && (follow('/', TRUE, FALSE) == TRUE)) {
                       finished = TRUE;
                    }
               }
             } else {
               return c;
             } 
          }
     }

  /* [b] : return end-of-file */

     if(c == EOF) {
        return END_OF_FILE;
     }

  /* [c] : read and store floating-point numbers */

     if (c == '.' || isdigit(c)) {
 	 double value;
	 ungetc(c, fin);
	 fscanf(fin, "%lf",  &value);

         if(fin == stdin && finp != stdin) fprintf(finp, "%lf", value);

	 yylval.sym = build_table("", NUMBER, value);
	 return NUMBER;
     }

  /* [d] : read and store variable */

     if (isalpha(c) || c == '_') {
 	 SYMBOL *s;
	 char	sbuf[100], *p = sbuf;

	 do {	
	    if(p >= sbuf + sizeof(sbuf) - 1) {
	       p = '\0';
	       EXECUTION_ERROR("ERROR >> name too long");
	    }
	    *p++ = c;
	 } while ((( c = fgetc(fin)) != EOF) && (isalnum(c) || (c == '_' )));

         ungetc(c, fin);
	 *p = '\0';

         if(fin == stdin && finp != stdin) fprintf(finp, "%s", sbuf);

	 if ((s = lookup(sbuf)) == 0) {
	      s = build_table(sbuf, VAR, 0.0);
	 }
	 yylval.sym = s;

         switch((int) s->type) {
 	    case  UNDEF:
            case  VAR:
            case  QUAN:
                  return VAR;
            default:
                  return (s->type);
         }
     }

  /* [e] : Get Quoted String */

     if (c == '"') {
         char sbuf[100], *p;
         if(fin == stdin && finp != stdin) fputc(c, finp);

	 for(p = sbuf; (c = fgetc(fin)) != '"'; p++) {
             if(c == '\n' || c == EOF)
                EXECUTION_ERROR("ERROR >> missing quote");
             if(p >= sbuf + sizeof(sbuf) - 1) {
                p = '\0';
                EXECUTION_ERROR("ERROR >> string name too long");
             }
             if((fin == stdin && finp != stdin))
                 fputc(c, finp);

		*p = backslash(c);
	 }
	 *p = 0;

         yylval.sym = (SYMBOL *) SaveString(sbuf);

         if(fin == stdin && finp != stdin) fputc(c, finp);

	 return STRING;
    }

    if(fin == stdin && finp != stdin) {
       fputc(c, finp);
    }

    switch(c) {
        case '>': 
             return follow('=',  GE,  GT);
        case '<':
             return follow('=',  LE,  LT);
        case '=':
             return follow('=',  EQ, '=');
        case '!':
             return follow('=',  NE, NOT);
        case '|':
             return follow('|',  OR, '|');
        case '&':
             return follow('&', AND, '&');
        case '\n':
             lineno = lineno + 1;
             return '\n';
        default:
	     return c;
    }
}

/* Error Traceback Routines */

int yyerror(s)
char *s;
{
     warning(s, (char *) 0);
}

int backslash(c)
int c;
{
char *index();
static char transtab[] = "b\bf\fn\nr\rt\t";

    if(c != '\\')
       return c;

    c = fgetc(fin);

    if(fin == stdin && finp != stdin) fputc(c, finp);

    if(islower(c) && index(transtab, c))
       return index(transtab, c)[1];

    return c;
}

int follow(expect, ifyes, ifno)
int expect, ifyes, ifno;
{
int c = fgetc(fin);

    if(c == expect) {
       if(fin == stdin && finp != stdin && ( c != '*' && c != '/') )  
          fputc(c, finp);

       return ifyes;
    }

    ungetc(c, fin);
    return ifno;
}

void Defn_Only(s)
char *s;
{
   if(!indef)
      EXECUTION_ERROR("ERROR >> Variable used outside definition", (char *) 0);
}

void fpecatch()
{
     EXECUTION_ERROR("Floating point exception", (char *) 0);
}

void EXECUTION_ERROR(s, t)
char *s, *t;
{
	warning(s, t);
	fseek(fin,0L,2);
	longjmp(begin,0);
}

void warning(s, t)
char *s, *t;
{
	fprintf(stderr, "%s: %s", progname, s);
	if(t)
	  fprintf(stderr,"ERROR >> %s",t);
	if(infile)
	  fprintf(stderr," in file '%s' ",infile);

        fprintf(stderr,"near line %d\n",lineno);
        FatalError("In Warning()",(char *)NULL);

        /* flush rest on file input */
	while(c == '\n' && c != EOF)
	      c = fgetc(fin);

	if(c == '\n')
	   lineno = lineno + 1;
}