📄 y_tab.c
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{
if (1 < yyrhs_count)
{ /* draw the graphics for the reduction */
YYDEBUG_INDENT(yynew_indent);
while(1 < yyrhs_count--)
printf("%s", YYDEBUG_REDUCE_STRING);
putchar('+'); /* left rotated L would look nice */
putchar('\n');
YYDEBUG_INDENT(yynew_indent);
putchar('|'); /* down arrow would look nice */
putchar('\n');
}
YYDEBUG_INDENT(yynew_indent);
/* Only print the resulting token name */
while (*yyrule_string && ' ' != *yyrule_string)
putchar(*yyrule_string++);
putchar('\n');
}
#endif /* YYDEBUG_REDUCE */
#ifndef YYDEBUG_SHIFT_LEXEME
YYDEBUG_SHIFT_LEXEME(yyold_state, yynew_state, yytoken_string, yynew_indent)
int yyold_state;
int yynew_state;
char * yytoken_string;
int yynew_indent;
{
YYDEBUG_INDENT(yynew_indent);
printf("%s <-- `%s'\n", yytoken_string, YYDEBUG_LEXER_TEXT);
}
#endif /* YYDEBUG_SHIFT_LEXEME */
#ifndef YYDEBUG_LOOK_AHEAD
YYDEBUG_LOOK_AHEAD(yynew_state, yytoken_num, yytoken_string, yyindent)
int yynew_state;
int yytoken_num;
char * yytoken_string;
int yyindent;
{
YYDEBUG_INDENT(yyindent);
printf(" .... look ahead at %s `%s'\n",
yytoken_string,
(0 == yytoken_num)? "\0": YYDEBUG_LEXER_TEXT);
}
#endif /* YYDEBUG_LOOK_AHEAD */
#ifndef YYDEBUG_DISCARD_STATE
YYDEBUG_DISCARD_STATE(yynew_state, yyindent)
int yynew_state;
int yyindent;
{
if (0 < yyindent)
{ /* draw the graphics for the reduction */
YYDEBUG_INDENT(yyindent-1);
printf("%s", YYDEBUG_REDUCE_STRING);
putchar('+'); /* left rotated L would look nice */
printf(" discarding state\n");
YYDEBUG_INDENT(yyindent-1);
putchar('|'); /* down arrow would look nice */
putchar('\n');
}
else
{
if (0 == yyindent)
printf("discarding state\n");
else
printf("no more states to discard: parser will abort\n");
}
}
#endif /* YYDEBUG_DISCARD_STATE */
#ifndef YYDEBUG_DISCARD_TOKEN
YYDEBUG_DISCARD_TOKEN(yynew_state, yytoken_num, yytoken_string, yyindent)
int yynew_state;
int yytoken_num;
char * yytoken_string;
int yyindent;
{
YYDEBUG_INDENT(yyindent);
printf("discarding token %s\n", yytoken_string);
}
#endif /* YYDEBUG_DISCARD_TOKEN */
#ifndef YYDEBUG_SHIFT_ERROR_LEXEME
YYDEBUG_SHIFT_ERROR_LEXEME(yyold_state, yynew_state, yyindent)
int yyold_state;
int yynew_state;
int yyindent;
{
YYDEBUG_INDENT(yyindent);
printf("error\n");
}
#endif /* YYDEBUG_SHIFT_ERROR_LEXEME */
#endif /* YYDEBUG */
int
yyparse()
{
register int yym, yyn, yystate;
#if YYDEBUG
register char *yys;
extern char *getenv();
if (yys = getenv("YYDEBUG"))
{
yyn = *yys;
if (yyn >= '0' && yyn <= '9')
yydebug = yyn - '0';
}
#endif
yynerrs = 0;
yyerrflag = 0;
yychar = (-1);
yyssp = yyss;
yyvsp = yyvs;
*yyssp = yystate = 0;
yyloop:
if (yyn = yydefred[yystate]) goto yyreduce;
if (yychar < 0)
{
if ((yychar = yylex()) < 0) yychar = 0;
#if YYDEBUG
if (yydebug)
{
yys = 0;
if (yychar <= YYMAXTOKEN) yys = yyname[yychar];
if (!yys) yys = "illegal-symbol";
if (5 > yydebug)
printf("yydebug: state %d, reading %d (%s)\n", yystate,
yychar, yys);
else
YYDEBUG_LOOK_AHEAD(yystate, yychar, yys, yyssp-yyss);
}
#endif
}
if ((yyn = yysindex[yystate]) && (yyn += yychar) >= 0 &&
yyn <= YYTABLESIZE && yycheck[yyn] == yychar)
{
#if YYDEBUG
if (yydebug)
if (5 > yydebug)
printf("yydebug: state %d, shifting to state %d\n",
yystate, yytable[yyn]);
else
YYDEBUG_SHIFT_LEXEME(yystate, yytable[yyn], yys, yyssp-yyss);
#endif
if (yyssp >= yyss + yystacksize - 1)
{
goto yyoverflow;
}
*++yyssp = yystate = yytable[yyn];
*++yyvsp = yylval;
yychar = (-1);
if (yyerrflag > 0) --yyerrflag;
goto yyloop;
}
if ((yyn = yyrindex[yystate]) && (yyn += yychar) >= 0 &&
yyn <= YYTABLESIZE && yycheck[yyn] == yychar)
{
yyn = yytable[yyn];
goto yyreduce;
}
if (yyerrflag) goto yyinrecovery;
#ifdef lint
goto yynewerror;
#endif
yynewerror:
yyerror("syntax error");
#ifdef lint
goto yyerrlab;
#endif
yyerrlab:
++yynerrs;
yyinrecovery:
if (yyerrflag < 3)
{
yyerrflag = 3;
for (;;)
{
if ((yyn = yysindex[*yyssp]) && (yyn += YYERRCODE) >= 0 &&
yyn <= YYTABLESIZE && yycheck[yyn] == YYERRCODE)
{
#if YYDEBUG
if (yydebug)
if (5 > yydebug)
printf("yydebug: state %d, error recovery shifting\
to state %d\n", *yyssp, yytable[yyn]);
else
YYDEBUG_SHIFT_ERROR_LEXEME(*yyssp, yytable[yyn], yyssp-yyss);
#endif
if (yyssp >= yyss + yystacksize - 1)
{
goto yyoverflow;
}
*++yyssp = yystate = yytable[yyn];
*++yyvsp = yylval;
goto yyloop;
}
else
{
#if YYDEBUG
if (yydebug)
if (5 > yydebug)
printf("yydebug: error recovery discarding state %d\n",
*yyssp);
else
YYDEBUG_DISCARD_STATE(*yyssp, yyssp-yyss-1);
#endif
if (yyssp <= yyss) goto yyabort;
--yyssp;
--yyvsp;
}
}
}
else
{
if (yychar == 0) goto yyabort;
#if YYDEBUG
if (yydebug)
{
yys = 0;
if (yychar <= YYMAXTOKEN) yys = yyname[yychar];
if (!yys) yys = "illegal-symbol";
if (5 > yydebug)
printf("yydebug: state %d, error recovery discards token %d (%s)\n",
yystate, yychar, yys);
else
YYDEBUG_DISCARD_TOKEN(yystate, yychar, yys, yyssp-yyss);
}
#endif
yychar = (-1);
goto yyloop;
}
yyreduce:
yym = yylen[yyn];
yyval = yyvsp[1-yym];
#if YYDEBUG
if (yydebug)
if (5 > yydebug)
printf("yydebug: state %d, reducing by rule %d (%s)\n",
yystate, yyn, yyrule[yyn]);
else
YYDEBUG_REDUCE(yystate, yyn, yyrule[yyn], yyssp-yyss-yym, yym);
#endif
switch (yyn)
{
case 1:
#line 77 "grammer.y"
{int i;printf("sym_off(符号个数)=%d\ncode_off(代码行数)=%d\n",sym_off,code_off);YYACCEPT;}
break;
case 2:
#line 79 "grammer.y"
{offset = 0;}
break;
case 3:
#line 80 "grammer.y"
{}
break;
case 4:
#line 81 "grammer.y"
{}
break;
case 5:
#line 83 "grammer.y"
{int p = lookup(yyvsp[-2].idname);
if(p!=-1){printf("error: line %d variable %s redefinition",yylineno,name+yyvsp[-2].idname);exit(1);}
/*$2.sym_off=p;*/
enterID(sym_off,yyvsp[-2].idname,symtab[yyvsp[0].sym_off].type);
yyvsp[-2].sym_off=sym_off++;
addType(yyvsp[-2].sym_off,symtab[yyvsp[0].sym_off].type);/*变量合法,add type and alloc memery space*/}
break;
case 6:
#line 92 "grammer.y"
{yyval.sym_off=sym_off++;symtab[yyval.sym_off].type=REAL;}
break;
case 7:
#line 93 "grammer.y"
{yyval.sym_off=sym_off++;symtab[yyval.sym_off].type=INT;}
break;
case 8:
#line 95 "grammer.y"
{backpatch(symtab[yyvsp[-1].sym_off].nextlist,symtab[yyvsp[0].sym_off].place);}
break;
case 9:
#line 97 "grammer.y"
{yyval.sym_off=sym_off++;
symtab[yyval.sym_off].nextlist=symtab[yyvsp[-1].sym_off].nextlist;
}
break;
case 10:
#line 101 "grammer.y"
{backpatch(symtab[yyvsp[-3].sym_off].nextlist,symtab[yyvsp[-1].sym_off].place);
yyval.sym_off=yyvsp[0].sym_off; }
break;
case 11:
#line 103 "grammer.y"
{yyval.sym_off=yyvsp[0].sym_off;}
break;
case 12:
#line 105 "grammer.y"
{yyval.sym_off=yyvsp[0].sym_off;}
break;
case 13:
#line 106 "grammer.y"
{yyval.sym_off=yyvsp[0].sym_off;}
break;
case 14:
#line 107 "grammer.y"
{yyval.sym_off=yyvsp[0].sym_off;}
break;
case 15:
#line 108 "grammer.y"
{yyval.sym_off=yyvsp[0].sym_off;}
break;
case 16:
#line 109 "grammer.y"
{yyval.sym_off=yyvsp[0].sym_off;}
break;
case 17:
#line 110 "grammer.y"
{yyval.sym_off=yyvsp[0].sym_off;}
break;
case 18:
#line 112 "grammer.y"
{if(symtab[yyvsp[-7].sym_off].type==BOOL/*&&symtab[$4.sym_off].type==symtab[$6.sym_off].type*/)
{/*不对语句设置类型*/
yyval.sym_off = sym_off++;
backpatch(symtab[yyvsp[-7].sym_off].truelist,symtab[yyvsp[-6].sym_off].place);
backpatch(symtab[yyvsp[-7].sym_off].falselist,symtab[yyvsp[-2].sym_off].place);
symtab[yyval.sym_off].nextlist = merge(symtab[yyvsp[-4].sym_off].nextlist,symtab[yyvsp[-1].sym_off].nextlist);
/*symtab[$$.sym_off].nextlist = merge(symtab[$$.sym_off].nextlist,symtab[$6.sym_off].nextlist); //开始按照教材上写,在ELSE前有符号N,再加上这一句,不能正确回填,去掉后正常*/
}
else type_error();}
break;
case 19:
#line 121 "grammer.y"
{if(symtab[yyvsp[-4].sym_off].type==BOOL)
{
yyval.sym_off = sym_off++;
backpatch(symtab[yyvsp[-4].sym_off].truelist,symtab[yyvsp[-3].sym_off].place);
symtab[yyval.sym_off].nextlist=merge(symtab[yyvsp[-4].sym_off].falselist,symtab[yyvsp[-1].sym_off].nextlist);
}
else type_error();}
break;
case 20:
#line 129 "grammer.y"
{yyval.sym_off=sym_off++;symtab[yyval.sym_off].place=code_off;}
break;
case 21:
#line 131 "grammer.y"
{
backpatch(symtab[yyvsp[0].sym_off].nextlist,symtab[yyvsp[-4].sym_off].place);
backpatch(symtab[yyvsp[-3].sym_off].truelist,symtab[yyvsp[-1].sym_off].place);
symtab[yyval.sym_off].nextlist=symtab[yyvsp[-3].sym_off].falselist;
/*emitCode(op_jmp,-1,-1,symtab[$2.sym_off].place);*/
}
break;
case 22:
#line 138 "grammer.y"
{int temp=0;
int p=lookup(yyvsp[-2].idname);
if(p==-1){printf("ERROR: line %d identifier %s undefined.",yylineno,name+yyvsp[-2].idname);exit(1);}
yyvsp[-2].sym_off=p;
yyval.sym_off=sym_off++;
if(symtab[yyvsp[-2].sym_off].type==symtab[yyvsp[0].sym_off].type)
{
symtab[yyval.sym_off].nextlist = makelist(code_off+1);
emitCode(op_mov,symtab[yyvsp[0].sym_off].place,-1,symtab[yyvsp[-2].sym_off].place);
emitCode(op_jmp,-1,-1,-1);
}
else if(symtab[yyvsp[-2].sym_off].type==REAL&&symtab[yyvsp[0].sym_off].type==INT)/*需要类型转换*/
{
/*symtab[$3.sym_off].type=REAL; //不能修改变量类型,原为bug*/
symtab[yyval.sym_off].nextlist = makelist(code_off+3);
temp=mem_off;
emitCode(op_mov,symtab[yyvsp[0].sym_off].place,-1,temp);
emitCode(op_inttoreal,temp,-1,temp);/*考虑到表达式的值只是临时变量,所以就在其上类型转换*/
emitCode(op_mov,temp,-1,symtab[yyvsp[-2].sym_off].place);
emitCode(op_jmp,-1,-1,-1);
}
else if(symtab[yyvsp[-2].sym_off].type==INT&&symtab[yyvsp[0].sym_off].type==REAL)/*需要类型转换*/
{
/*symtab[$3.sym_off].type=INT;*/
symtab[yyval.sym_off].nextlist = makelist(code_off+3); /*此处设置不正确,导致bug*/
temp=mem_off;
emitCode(op_mov,symtab[yyvsp[0].sym_off].place,-1,temp);
emitCode(op_realtoint,temp,-1,temp);/*考虑到表达式的值只是临时变量,所以就在其上类型转换*/
emitCode(op_mov,temp,-1,symtab[yyvsp[-2].sym_off].place);
emitCode(op_jmp,-1,-1,-1);
}
else type_error();}
break;
case 23:
#line 172 "grammer.y"
{int p=lookup(yyvsp[0].idname);
if(p==-1){printf("ERROR: line %d identifier %s is undefined.",yylineno,name+yyvsp[0].idname);exit(1);}
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