📄 y.tab.c
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//return TRUE;
}
void emitCode( enum code_ops operation, int src1 ,int src2 , int dest )
{
code[code_off].op = operation;
code[code_off].src1.isrc1 = src1;
code[code_off].src2 = src2;
code[code_off].dest = dest;
code_off++;
}
void emitFCode( enum code_ops operation, double src1 ,int src2 , int dest )
{
code[code_off].op = operation;
code[code_off].src1.fsrc1 = src1;
code[code_off].src2 = src2;
code[code_off].dest = dest;
code_off++;
}
void backpatch( struct Jmplist * list, int jmp_dest) /*把指令序号i所相应的指令地址回填到由指针p指向的转移指令中*/
{
struct Jmplist * temp=list; /*回填后释放内存,*/
while(list!=NULL)
{
code[list->index].dest = jmp_dest;
list=list->next;
free(temp); /*释放内存*/
temp=list;
}
}
struct Jmplist * merge(struct Jmplist * list1,struct Jmplist * list2)
{
list1->next = list2;
return list1;
}
struct Jmplist * makelist(int i) /*建立仅含有指令诒i的新转移指令表,回头该表的指针*/
{
struct Jmplist * list = (struct Jmplist *)malloc(sizeof(struct Jmplist));
list->index = i;
list->next = NULL;
return list;
}
void yyerror(char * s)
{
fflush(stdout);
printf("ERROR:line %d",yylineno);
}
void type_error()
{
printf("ERROR: line %d type error",yylineno);
}
#line 445 "y.tab.c"
#define YYABORT goto yyabort
#define YYACCEPT goto yyaccept
#define YYERROR goto yyerrlab
#if YYDEBUG
#ifdef __cplusplus
extern "C" char *getenv();
#else
extern char *getenv();
#endif
#endif
int
yyparse()
{
register int yym, yyn, yystate;
register YYSTYPE *yyvsp;
register short *yyssp;
short *yysse;
#if YYDEBUG
register YYCONST char *yys;
if (yys = getenv("YYDEBUG"))
{
yyn = *yys;
if (yyn >= '0' && yyn <= '9')
yydebug = yyn - '0';
}
#endif
yynerrs = 0;
yyerrflag = 0;
yychar = (-1);
if (yyss == 0)
{
yyss = (short *) yymalloc (YYSTACKSIZE * sizeof (short));
if (yyss == 0)
goto yyabort;
yyvs = (YYSTYPE *) yymalloc (YYSTACKSIZE * sizeof (YYSTYPE));
if (yyvs == 0)
{
yyfree (yyss);
goto yyabort;
}
yystacksize = YYSTACKSIZE;
}
yysse = yyss + yystacksize - 1;
yyssp = yyss;
yyvsp = yyvs;
*yyssp = yystate = 0;
goto yyloop;
yypush_lex:
yyval = yylval;
yystate = yytable[yyn];
yypush:
if (yyssp >= yysse)
{
int depth = yyssp - yyss;
if (yygrow() != 0)
goto yyoverflow;
yysse = yyss + yystacksize -1;
yyssp = depth + yyss;
yyvsp = depth + yyvs;
}
*++yyssp = yystate;
*++yyvsp = yyval;
yyloop:
if (yyn = yydefred[yystate]) goto yyreduce;
yyn = yysindex[yystate];
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";
printf("yydebug: state %d, reading %d (%s)\n", yystate,
yychar, yys);
}
#endif
}
if (yyn != 0
&& ((yyn += yychar), ((unsigned)yyn <= (unsigned)YYTABLESIZE))
&& yycheck[yyn] == yychar)
{
#if YYDEBUG
if (yydebug)
printf("yydebug: state %d, shifting to state %d\n",
yystate, yytable[yyn]);
#endif
if (yyerrflag > 0) --yyerrflag;
yychar = (-1);
goto yypush_lex;
}
yyn = yyrindex[yystate];
if (yyn != 0
&& ((yyn += yychar), ((unsigned)yyn <= (unsigned)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 (;;)
{
yyn = yysindex[*yyssp];
if (yyn != 0
&& ((yyn += YYERRCODE), ((unsigned)yyn <= (unsigned)YYTABLESIZE))
&& yycheck[yyn] == YYERRCODE)
{
#if YYDEBUG
if (yydebug)
printf("yydebug: state %d, error recovery shifting\
to state %d\n", *yyssp, yytable[yyn]);
#endif
goto yypush_lex;
}
else
{
#if YYDEBUG
if (yydebug)
printf("yydebug: error recovery discarding state %d\n",
*yyssp);
#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";
printf("yydebug: state %d, error recovery discards token %d (%s)\n",
yystate, yychar, yys);
}
#endif
yychar = (-1);
goto yyloop;
}
yyreduce:
#if YYDEBUG
if (yydebug)
printf("yydebug: state %d, reducing by rule %d (%s)\n",
yystate, yyn, yyrule[yyn]);
#endif
yym = yylen[yyn];
yyval = yyvsp[1-yym];
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);}
yyvsp[0].sym_off=p;
yyval.sym_off=sym_off++;
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