各位大虾，现急需一c程序，有意者，还来看看啊！！！！1

[changlong876]

我们让学一个c语言语法分析程序，语言不限，但最好用c语言来实现！！！！！！

[iu_81]

http://dev.21tx.com/2005/05/12/15870.html

[yzcurry]

没下文了啊?
没看明白什么

[freshui]

Lex & Yacc
再加上C语言
我正在用这个做assembler

[freshui]

ANSI C grammar, Lex specification
In 1985, Jeff Lee published this Lex specification together with a Yacc grammar for the April 30, 1985 ANSI C draft. Tom Stockfisch reposted both to net.sources in 1987; that original, as mentioned in the answer to question 17.25 of the comp.lang.c FAQ, can be ftp'ed from ftp.uu.net, file usenet/net.sources/ansi.c.grammar.Z.
I intend to keep this version as close to the current C Standard grammar as possible; please let me know if you discover discrepancies.

Jutta Degener, 1995



--------------------------------------------------------------------------------


D [0-9]
L [a-zA-Z_]
H [a-fA-F0-9]
E [Ee][+-]?{D}+
FS (f|F|l|L)
IS (u|U|l|L)*

%{
#include <stdio.h>
#include "y.tab.h"

void count();
%}

%%
"/*" { comment(); }

"auto" { count(); return(AUTO); }
"break" { count(); return(BREAK); }
"case" { count(); return(CASE); }
"char" { count(); return(CHAR); }
"const" { count(); return(CONST); }
"continue" { count(); return(CONTINUE); }
"default" { count(); return(DEFAULT); }
"do" { count(); return(DO); }
"double" { count(); return(DOUBLE); }
"else" { count(); return(ELSE); }
"enum" { count(); return(ENUM); }
"extern" { count(); return(EXTERN); }
"float" { count(); return(FLOAT); }
"for" { count(); return(FOR); }
"goto" { count(); return(GOTO); }
"if" { count(); return(IF); }
"int" { count(); return(INT); }
"long" { count(); return(LONG); }
"register" { count(); return(REGISTER); }
"return" { count(); return(RETURN); }
"short" { count(); return(SHORT); }
"signed" { count(); return(SIGNED); }
"sizeof" { count(); return(SIZEOF); }
"static" { count(); return(STATIC); }
"struct" { count(); return(STRUCT); }
"switch" { count(); return(SWITCH); }
"typedef" { count(); return(TYPEDEF); }
"union" { count(); return(UNION); }
"unsigned" { count(); return(UNSIGNED); }
"void" { count(); return(VOID); }
"volatile" { count(); return(VOLATILE); }
"while" { count(); return(WHILE); }

{L}({L}|{D})* { count(); return(check_type()); }

0[xX]{H}+{IS}? { count(); return(CONSTANT); }
0{D}+{IS}? { count(); return(CONSTANT); }
{D}+{IS}? { count(); return(CONSTANT); }
'(\\.|[^\\'])+' { count(); return(CONSTANT); }

{D}+{E}{FS}? { count(); return(CONSTANT); }
{D}*"."{D}+({E})?{FS}? { count(); return(CONSTANT); }
{D}+"."{D}*({E})?{FS}? { count(); return(CONSTANT); }

\"(\\.|[^\\"])*\" { count(); return(STRING_LITERAL); }

"..." { count(); return(ELLIPSIS); }
">>=" { count(); return(RIGHT_ASSIGN); }
"<<=" { count(); return(LEFT_ASSIGN); }
"+=" { count(); return(ADD_ASSIGN); }
"-=" { count(); return(SUB_ASSIGN); }
"*=" { count(); return(MUL_ASSIGN); }
"/=" { count(); return(DIV_ASSIGN); }
"%=" { count(); return(MOD_ASSIGN); }
"&=" { count(); return(AND_ASSIGN); }
"^=" { count(); return(XOR_ASSIGN); }
"|=" { count(); return(OR_ASSIGN); }
">>" { count(); return(RIGHT_OP); }
"<<" { count(); return(LEFT_OP); }
"++" { count(); return(INC_OP); }
"--" { count(); return(DEC_OP); }
"->" { count(); return(PTR_OP); }
"&&" { count(); return(AND_OP); }
"||" { count(); return(OR_OP); }
"<=" { count(); return(LE_OP); }
">=" { count(); return(GE_OP); }
"==" { count(); return(EQ_OP); }
"!=" { count(); return(NE_OP); }
";" { count(); return(';'); }
"{" { count(); return('{'); }
"}" { count(); return('}'); }
"," { count(); return(','); }
":" { count(); return(':'); }
"=" { count(); return('='); }
"(" { count(); return('('); }
")" { count(); return(')'); }
"[" { count(); return('['); }
"]" { count(); return(']'); }
"." { count(); return('.'); }
"&" { count(); return('&'); }
"!" { count(); return('!'); }
"~" { count(); return('~'); }
"-" { count(); return('-'); }
"+" { count(); return('+'); }
"*" { count(); return('*'); }
"/" { count(); return('/'); }
"%" { count(); return('%'); }
"<" { count(); return('<'); }
">" { count(); return('>'); }
"^" { count(); return('^'); }
"|" { count(); return('|'); }
"?" { count(); return('?'); }

[ \t\v\n\f] { count(); }
. { /* ignore bad characters */ }

%%

yywrap()
{
return(1);
}


comment()
{
char c, c1;

loop:
while ((c = input()) != '*' && c != 0)
putchar(c);

if ((c1 = input()) != '/' && c != 0)
{
unput(c1);
goto loop;
}

if (c != 0)
putchar(c1);
}


int column = 0;

void count()
{
int i;

for (i = 0; yytext[i] != '\0'; i++)
if (yytext[i] == '\n')
column = 0;
else if (yytext[i] == '\t')
column += 8 - (column % 8);
else
column++;

ECHO;
}


int check_type()
{
/*
* pseudo code --- this is what it should check
*
* if (yytext == type_name)
* return(TYPE_NAME);
*
* return(IDENTIFIER);
*/

/*
* it actually will only return IDENTIFIER
*/

return(IDENTIFIER);
}

[freshui]

ANSI C Yacc grammar
In 1985, Jeff Lee published his Yacc grammar (which is accompanied by a matching Lex specification) for the April 30, 1985 draft version of the ANSI C standard. Tom Stockfisch reposted it to net.sources in 1987; that original, as mentioned in the answer to question 17.25 of the comp.lang.c FAQ, can be ftp'ed from ftp.uu.net, file usenet/net.sources/ansi.c.grammar.Z.
I intend to keep this version as close to the current C Standard grammar as possible; please let me know if you discover discrepancies.

Jutta Degener, 1995



--------------------------------------------------------------------------------

%token IDENTIFIER CONSTANT STRING_LITERAL SIZEOF
%token PTR_OP INC_OP DEC_OP LEFT_OP RIGHT_OP LE_OP GE_OP EQ_OP NE_OP
%token AND_OP OR_OP MUL_ASSIGN DIV_ASSIGN MOD_ASSIGN ADD_ASSIGN
%token SUB_ASSIGN LEFT_ASSIGN RIGHT_ASSIGN AND_ASSIGN
%token XOR_ASSIGN OR_ASSIGN TYPE_NAME

%token TYPEDEF EXTERN STATIC AUTO REGISTER
%token CHAR SHORT INT LONG SIGNED UNSIGNED FLOAT DOUBLE CONST VOLATILE VOID
%token STRUCT UNION ENUM ELLIPSIS

%token CASE DEFAULT IF ELSE SWITCH WHILE DO FOR GOTO CONTINUE BREAK RETURN

%start translation_unit
%%

primary_expression
: IDENTIFIER
| CONSTANT
| STRING_LITERAL
| '(' expression ')'
;

postfix_expression
: primary_expression
| postfix_expression '[' expression ']'
| postfix_expression '(' ')'
| postfix_expression '(' argument_expression_list ')'
| postfix_expression '.' IDENTIFIER
| postfix_expression PTR_OP IDENTIFIER
| postfix_expression INC_OP
| postfix_expression DEC_OP
;

argument_expression_list
: assignment_expression
| argument_expression_list ',' assignment_expression
;

unary_expression
: postfix_expression
| INC_OP unary_expression
| DEC_OP unary_expression
| unary_operator cast_expression
| SIZEOF unary_expression
| SIZEOF '(' type_name ')'
;

unary_operator
: '&'
| '*'
| '+'
| '-'
| '~'
| '!'
;

cast_expression
: unary_expression
| '(' type_name ')' cast_expression
;

multiplicative_expression
: cast_expression
| multiplicative_expression '*' cast_expression
| multiplicative_expression '/' cast_expression
| multiplicative_expression '%' cast_expression
;

additive_expression
: multiplicative_expression
| additive_expression '+' multiplicative_expression
| additive_expression '-' multiplicative_expression
;

shift_expression
: additive_expression
| shift_expression LEFT_OP additive_expression
| shift_expression RIGHT_OP additive_expression
;

relational_expression
: shift_expression
| relational_expression '<' shift_expression
| relational_expression '>' shift_expression
| relational_expression LE_OP shift_expression
| relational_expression GE_OP shift_expression
;

equality_expression
: relational_expression
| equality_expression EQ_OP relational_expression
| equality_expression NE_OP relational_expression
;

and_expression
: equality_expression
| and_expression '&' equality_expression
;

exclusive_or_expression
: and_expression
| exclusive_or_expression '^' and_expression
;

inclusive_or_expression
: exclusive_or_expression
| inclusive_or_expression '|' exclusive_or_expression
;

logical_and_expression
: inclusive_or_expression
| logical_and_expression AND_OP inclusive_or_expression
;

logical_or_expression
: logical_and_expression
| logical_or_expression OR_OP logical_and_expression
;

conditional_expression
: logical_or_expression
| logical_or_expression '?' expression ':' conditional_expression
;

assignment_expression
: conditional_expression
| unary_expression assignment_operator assignment_expression
;

assignment_operator
: '='
| MUL_ASSIGN
| DIV_ASSIGN
| MOD_ASSIGN
| ADD_ASSIGN
| SUB_ASSIGN
| LEFT_ASSIGN
| RIGHT_ASSIGN
| AND_ASSIGN
| XOR_ASSIGN
| OR_ASSIGN
;