he91_com
- 浏览: 375742 次
-
文章分类
最新评论
-
tedeum：
美帝人民不为钱写代码是因为万恶的资本主义社会保障制度
读《20个月赚130亿》有感 -
novembersky：
还好你没相信那个大饼
谁坑了程序员的职业道德？送给初入职的码农，和宣传奴性的领导。 -
禀圣含华：
也不要着急进一家公司，就因为那公司急着招人。。急着招人背后又是 ...
谁坑了程序员的职业道德？送给初入职的码农，和宣传奴性的领导。 -
haohao-xuexi02：
每个码奴辛辛苦苦最后，还不能干脆的走。。各种被坑。。。
找工作 ...
谁坑了程序员的职业道德？送给初入职的码农，和宣传奴性的领导。 -
hot002：
BuN_Ny 写道真实项目中的6种人：1.怂恿者2.批评者3. ...
一个优秀创业团队需要的6种人
《flex与bison》读书笔记--ch01 flex和bison简介（上）
说起flex，大多数人第一感觉是adobe的 Flex，包括百度、Google也是这么认为，看来Flex确实是热火朝天啊，等有空了也玩下Adobe的Flex。为了不和Adobe的产品混淆，这里统统用flex来指快速文法分析器。
--------------------------------------------------------------
flex和bison是用来生成程序的工具，它们所生成的程序能够处理结构化输入。
词法分析和语法分析
词法分析（lexical analysis，或scanning）把输入分割成一个个有意义的词块，称为记号（token）。用编译原理课本中的话来说，词法分析的过程就是识别单词的过程，输入的是字符串，输出的是单词。
语法分析（syntax analysis，或parsing）确定这些记号是如何彼此关联的。用编译原理课本中的话来说，语法分析的过程就是识别句子的过程，输入的是单词，输出的是句子。
正则表达式和词法分析
词法分析通常所做的就是在输入中寻找字符的模式（pattern）。一种简洁明了的模式描述方式就是正则表达式（regular expression，常简写为regex或regexp）。编辑器ed和vi以及搜索程序grep就是用这种方式来描述其所要查找的文本。flex程序主要由一系列带有指令的正则表达式组成，这些指令确定了正则表达式匹配后响应的动作（action）。由flex生成的词法分析器可以读取输入，匹配输入与所有的正则表达式并且执行每次匹配后适当的关联动作。flex会把所有的正则表达式翻译成一种高效的内部格式，这使它几乎可以同时处理所有需要匹配的模式，因此它的速度可以成百倍地提高。这种内部格式使用确定性有穷自动机（DeterministicFiniteAutomation，DFA）。对于DFA，他们的处理速度与模式的个数和复杂度无关。
/* wc程序 */
%{
int chars = 0;
int words = 0;
int lines = 0;
}%
%%
[a-zA-Z]+ { words++; chars += strlen(yytext);}
\n { chars++; lines++;}
. { chars++;}
%%
main(int argc, char **argv)
{
yylex();
printf("%8d%8d%8d\n", lines, words, chars);
}
flex程序包含3个部分，各部分之间通过仅有%%的行来分割。
第1部分：包含声明和选项设置。在这部分，%{和}%之间的代码会被原样照抄到生成的C文件的开头部分。在这个例子里面，它只是用来设定了行数、单词数和字符数的变量。
第2部分：一系列的模式和动作。这部分中，每个模式处在一行的开头处，接着是模式匹配时所需要执行的C代码。这儿的C代码使用{}括住的一行或者多行语句。（模式必须在行首出现，因为flex认为以空白开始的行都是代码而把它们照抄到生成的C程序中。）
第3部分：会被拷贝到生成的词法分析器里面的C代码，它们一般是一些与动作代码相关的例程。这个主程序负责调用flex提供的词法分析例程yylex（），并输出结果。在没有任何其他改变的情况下，词法分析器将读取标准输入。
将上面的代码存为wc.l并执行：flex -o wc.c wc.l 后生成wc.c文件，其内容如下：
#line 2 "wc.c"
#line 4 "wc.c"
#define YY_INT_ALIGNED short int
/* A lexical scanner generated by flex */
#define FLEX_SCANNER
#define YY_FLEX_MAJOR_VERSION 2
#define YY_FLEX_MINOR_VERSION 5
#define YY_FLEX_SUBMINOR_VERSION 37
#if YY_FLEX_SUBMINOR_VERSION > 0
#define FLEX_BETA
#endif
/* First, we deal with platform-specific or compiler-specific issues. */
/* begin standard C headers. */
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
/* end standard C headers. */
/* flex integer type definitions */
#ifndef FLEXINT_H
#define FLEXINT_H
/* C99 systems have <inttypes.h>. Non-C99 systems may or may not. */
#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
/* C99 says to define __STDC_LIMIT_MACROS before including stdint.h,
* if you want the limit (max/min) macros for int types.
*/
#ifndef __STDC_LIMIT_MACROS
#define __STDC_LIMIT_MACROS 1
#endif
#include <inttypes.h>
typedef int8_t flex_int8_t;
typedef uint8_t flex_uint8_t;
typedef int16_t flex_int16_t;
typedef uint16_t flex_uint16_t;
typedef int32_t flex_int32_t;
typedef uint32_t flex_uint32_t;
#else
typedef signed char flex_int8_t;
typedef short int flex_int16_t;
typedef int flex_int32_t;
typedef unsigned char flex_uint8_t;
typedef unsigned short int flex_uint16_t;
typedef unsigned int flex_uint32_t;
/* Limits of integral types. */
#ifndef INT8_MIN
#define INT8_MIN (-128)
#endif
#ifndef INT16_MIN
#define INT16_MIN (-32767-1)
#endif
#ifndef INT32_MIN
#define INT32_MIN (-2147483647-1)
#endif
#ifndef INT8_MAX
#define INT8_MAX (127)
#endif
#ifndef INT16_MAX
#define INT16_MAX (32767)
#endif
#ifndef INT32_MAX
#define INT32_MAX (2147483647)
#endif
#ifndef UINT8_MAX
#define UINT8_MAX (255U)
#endif
#ifndef UINT16_MAX
#define UINT16_MAX (65535U)
#endif
#ifndef UINT32_MAX
#define UINT32_MAX (4294967295U)
#endif
#endif /* ! C99 */
#endif /* ! FLEXINT_H */
#ifdef __cplusplus
/* The "const" storage-class-modifier is valid. */
#define YY_USE_CONST
#else /* ! __cplusplus */
/* C99 requires __STDC__ to be defined as 1. */
#if defined (__STDC__)
#define YY_USE_CONST
#endif /* defined (__STDC__) */
#endif /* ! __cplusplus */
#ifdef YY_USE_CONST
#define yyconst const
#else
#define yyconst
#endif
/* Returned upon end-of-file. */
#define YY_NULL 0
/* Promotes a possibly negative, possibly signed char to an unsigned
* integer for use as an array index. If the signed char is negative,
* we want to instead treat it as an 8-bit unsigned char, hence the
* double cast.
*/
#define YY_SC_TO_UI(c) ((unsigned int) (unsigned char) c)
/* Enter a start condition. This macro really ought to take a parameter,
* but we do it the disgusting crufty way forced on us by the ()-less
* definition of BEGIN.
*/
#define BEGIN (yy_start) = 1 + 2 *
/* Translate the current start state into a value that can be later handed
* to BEGIN to return to the state. The YYSTATE alias is for lex
* compatibility.
*/
#define YY_START (((yy_start) - 1) / 2)
#define YYSTATE YY_START
/* Action number for EOF rule of a given start state. */
#define YY_STATE_EOF(state) (YY_END_OF_BUFFER + state + 1)
/* Special action meaning "start processing a new file". */
#define YY_NEW_FILE yyrestart(yyin )
#define YY_END_OF_BUFFER_CHAR 0
/* Size of default input buffer. */
#ifndef YY_BUF_SIZE
#define YY_BUF_SIZE 16384
#endif
/* The state buf must be large enough to hold one state per character in the main buffer.
*/
#define YY_STATE_BUF_SIZE ((YY_BUF_SIZE + 2) * sizeof(yy_state_type))
#ifndef YY_TYPEDEF_YY_BUFFER_STATE
#define YY_TYPEDEF_YY_BUFFER_STATE
typedef struct yy_buffer_state *YY_BUFFER_STATE;
#endif
#ifndef YY_TYPEDEF_YY_SIZE_T
#define YY_TYPEDEF_YY_SIZE_T
typedef size_t yy_size_t;
#endif
extern yy_size_t yyleng;
extern FILE *yyin, *yyout;
#define EOB_ACT_CONTINUE_SCAN 0
#define EOB_ACT_END_OF_FILE 1
#define EOB_ACT_LAST_MATCH 2
#define YY_LESS_LINENO(n)
/* Return all but the first "n" matched characters back to the input stream. */
#define yyless(n) \
do \
{ \
/* Undo effects of setting up yytext. */ \
int yyless_macro_arg = (n); \
YY_LESS_LINENO(yyless_macro_arg);\
*yy_cp = (yy_hold_char); \
YY_RESTORE_YY_MORE_OFFSET \
(yy_c_buf_p) = yy_cp = yy_bp + yyless_macro_arg - YY_MORE_ADJ; \
YY_DO_BEFORE_ACTION; /* set up yytext again */ \
} \
while ( 0 )
#define unput(c) yyunput( c, (yytext_ptr) )
#ifndef YY_STRUCT_YY_BUFFER_STATE
#define YY_STRUCT_YY_BUFFER_STATE
struct yy_buffer_state
{
FILE *yy_input_file;
char *yy_ch_buf; /* input buffer */
char *yy_buf_pos; /* current position in input buffer */
/* Size of input buffer in bytes, not including room for EOB
* characters.
*/
yy_size_t yy_buf_size;
/* Number of characters read into yy_ch_buf, not including EOB
* characters.
*/
yy_size_t yy_n_chars;
/* Whether we "own" the buffer - i.e., we know we created it,
* and can realloc() it to grow it, and should free() it to
* delete it.
*/
int yy_is_our_buffer;
/* Whether this is an "interactive" input source; if so, and
* if we're using stdio for input, then we want to use getc()
* instead of fread(), to make sure we stop fetching input after
* each newline.
*/
int yy_is_interactive;
/* Whether we're considered to be at the beginning of a line.
* If so, '^' rules will be active on the next match, otherwise
* not.
*/
int yy_at_bol;
int yy_bs_lineno; /**< The line count. */
int yy_bs_column; /**< The column count. */
/* Whether to try to fill the input buffer when we reach the
* end of it.
*/
int yy_fill_buffer;
int yy_buffer_status;
#define YY_BUFFER_NEW 0
#define YY_BUFFER_NORMAL 1
/* When an EOF's been seen but there's still some text to process
* then we mark the buffer as YY_EOF_PENDING, to indicate that we
* shouldn't try reading from the input source any more. We might
* still have a bunch of tokens to match, though, because of
* possible backing-up.
*
* When we actually see the EOF, we change the status to "new"
* (via yyrestart()), so that the user can continue scanning by
* just pointing yyin at a new input file.
*/
#define YY_BUFFER_EOF_PENDING 2
};
#endif /* !YY_STRUCT_YY_BUFFER_STATE */
/* Stack of input buffers. */
static size_t yy_buffer_stack_top = 0; /**< index of top of stack. */
static size_t yy_buffer_stack_max = 0; /**< capacity of stack. */
static YY_BUFFER_STATE * yy_buffer_stack = 0; /**< Stack as an array. */
/* We provide macros for accessing buffer states in case in the
* future we want to put the buffer states in a more general
* "scanner state".
*
* Returns the top of the stack, or NULL.
*/
#define YY_CURRENT_BUFFER ( (yy_buffer_stack) \
? (yy_buffer_stack)[(yy_buffer_stack_top)] \
: NULL)
/* Same as previous macro, but useful when we know that the buffer stack is not
* NULL or when we need an lvalue. For internal use only.
*/
#define YY_CURRENT_BUFFER_LVALUE (yy_buffer_stack)[(yy_buffer_stack_top)]
/* yy_hold_char holds the character lost when yytext is formed. */
static char yy_hold_char;
static yy_size_t yy_n_chars; /* number of characters read into yy_ch_buf */
yy_size_t yyleng;
/* Points to current character in buffer. */
static char *yy_c_buf_p = (char *) 0;
static int yy_init = 0; /* whether we need to initialize */
static int yy_start = 0; /* start state number */
/* Flag which is used to allow yywrap()'s to do buffer switches
* instead of setting up a fresh yyin. A bit of a hack ...
*/
static int yy_did_buffer_switch_on_eof;
void yyrestart (FILE *input_file );
void yy_switch_to_buffer (YY_BUFFER_STATE new_buffer );
YY_BUFFER_STATE yy_create_buffer (FILE *file,int size );
void yy_delete_buffer (YY_BUFFER_STATE b );
void yy_flush_buffer (YY_BUFFER_STATE b );
void yypush_buffer_state (YY_BUFFER_STATE new_buffer );
void yypop_buffer_state (void );
static void yyensure_buffer_stack (void );
static void yy_load_buffer_state (void );
static void yy_init_buffer (YY_BUFFER_STATE b,FILE *file );
#define YY_FLUSH_BUFFER yy_flush_buffer(YY_CURRENT_BUFFER )
YY_BUFFER_STATE yy_scan_buffer (char *base,yy_size_t size );
YY_BUFFER_STATE yy_scan_string (yyconst char *yy_str );
YY_BUFFER_STATE yy_scan_bytes (yyconst char *bytes,yy_size_t len );
void *yyalloc (yy_size_t );
void *yyrealloc (void *,yy_size_t );
void yyfree (void * );
#define yy_new_buffer yy_create_buffer
#define yy_set_interactive(is_interactive) \
{ \
if ( ! YY_CURRENT_BUFFER ){ \
yyensure_buffer_stack (); \
YY_CURRENT_BUFFER_LVALUE = \
yy_create_buffer(yyin,YY_BUF_SIZE ); \
} \
YY_CURRENT_BUFFER_LVALUE->yy_is_interactive = is_interactive; \
}
#define yy_set_bol(at_bol) \
{ \
if ( ! YY_CURRENT_BUFFER ){\
yyensure_buffer_stack (); \
YY_CURRENT_BUFFER_LVALUE = \
yy_create_buffer(yyin,YY_BUF_SIZE ); \
} \
YY_CURRENT_BUFFER_LVALUE->yy_at_bol = at_bol; \
}
#define YY_AT_BOL() (YY_CURRENT_BUFFER_LVALUE->yy_at_bol)
/* Begin user sect3 */
typedef unsigned char YY_CHAR;
FILE *yyin = (FILE *) 0, *yyout = (FILE *) 0;
typedef int yy_state_type;
extern int yylineno;
int yylineno = 1;
extern char *yytext;
#define yytext_ptr yytext
static yy_state_type yy_get_previous_state (void );
static yy_state_type yy_try_NUL_trans (yy_state_type current_state );
static int yy_get_next_buffer (void );
static void yy_fatal_error (yyconst char msg[] );
/* Done after the current pattern has been matched and before the
* corresponding action - sets up yytext.
*/
#define YY_DO_BEFORE_ACTION \
(yytext_ptr) = yy_bp; \
yyleng = (size_t) (yy_cp - yy_bp); \
(yy_hold_char) = *yy_cp; \
*yy_cp = '\0'; \
(yy_c_buf_p) = yy_cp;
#define YY_NUM_RULES 4
#define YY_END_OF_BUFFER 5
/* This struct is not used in this scanner,
but its presence is necessary. */
struct yy_trans_info
{
flex_int32_t yy_verify;
flex_int32_t yy_nxt;
};
static yyconst flex_int16_t yy_accept[9] =
{ 0,
0, 0, 5, 3, 2, 1, 1, 0
} ;
static yyconst flex_int32_t yy_ec[256] =
{ 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 2,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
1, 1, 1, 1, 1, 1, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
3, 3, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1
} ;
static yyconst flex_int32_t yy_meta[4] =
{ 0,
1, 1, 2
} ;
static yyconst flex_int16_t yy_base[10] =
{ 0,
0, 0, 5, 6, 6, 0, 0, 6, 2
} ;
static yyconst flex_int16_t yy_def[10] =
{ 0,
8, 1, 8, 8, 8, 9, 9, 0, 8
} ;
static yyconst flex_int16_t yy_nxt[10] =
{ 0,
4, 5, 6, 7, 8, 3, 8, 8, 8
} ;
static yyconst flex_int16_t yy_chk[10] =
{ 0,
1, 1, 1, 9, 3, 8, 8, 8, 8
} ;
static yy_state_type yy_last_accepting_state;
static char *yy_last_accepting_cpos;
extern int yy_flex_debug;
int yy_flex_debug = 0;
/* The intent behind this definition is that it'll catch
* any uses of REJECT which flex missed.
*/
#define REJECT reject_used_but_not_detected
#define yymore() yymore_used_but_not_detected
#define YY_MORE_ADJ 0
#define YY_RESTORE_YY_MORE_OFFSET
char *yytext;
#line 1 "wc.l"
/* wc */
#line 3 "wc.l"
int chars = 0;
int words = 0;
int lines = 0;
#line 456 "wc.c"
#define INITIAL 0
#ifndef YY_NO_UNISTD_H
/* Special case for "unistd.h", since it is non-ANSI. We include it way
* down here because we want the user's section 1 to have been scanned first.
* The user has a chance to override it with an option.
*/
#include <unistd.h>
#endif
#ifndef YY_EXTRA_TYPE
#define YY_EXTRA_TYPE void *
#endif
static int yy_init_globals (void );
/* Accessor methods to globals.
These are made visible to non-reentrant scanners for convenience. */
int yylex_destroy (void );
int yyget_debug (void );
void yyset_debug (int debug_flag );
YY_EXTRA_TYPE yyget_extra (void );
void yyset_extra (YY_EXTRA_TYPE user_defined );
FILE *yyget_in (void );
void yyset_in (FILE * in_str );
FILE *yyget_out (void );
void yyset_out (FILE * out_str );
yy_size_t yyget_leng (void );
char *yyget_text (void );
int yyget_lineno (void );
void yyset_lineno (int line_number );
/* Macros after this point can all be overridden by user definitions in
* section 1.
*/
#ifndef YY_SKIP_YYWRAP
#ifdef __cplusplus
extern "C" int yywrap (void );
#else
extern int yywrap (void );
#endif
#endif
static void yyunput (int c,char *buf_ptr );
#ifndef yytext_ptr
static void yy_flex_strncpy (char *,yyconst char *,int );
#endif
#ifdef YY_NEED_STRLEN
static int yy_flex_strlen (yyconst char * );
#endif
#ifndef YY_NO_INPUT
#ifdef __cplusplus
static int yyinput (void );
#else
static int input (void );
#endif
#endif
/* Amount of stuff to slurp up with each read. */
#ifndef YY_READ_BUF_SIZE
#define YY_READ_BUF_SIZE 8192
#endif
/* Copy whatever the last rule matched to the standard output. */
#ifndef ECHO
/* This used to be an fputs(), but since the string might contain NUL's,
* we now use fwrite().
*/
#define ECHO do { if (fwrite( yytext, yyleng, 1, yyout )) {} } while (0)
#endif
/* Gets input and stuffs it into "buf". number of characters read, or YY_NULL,
* is returned in "result".
*/
#ifndef YY_INPUT
#define YY_INPUT(buf,result,max_size) \
if ( YY_CURRENT_BUFFER_LVALUE->yy_is_interactive ) \
{ \
int c = '*'; \
size_t n; \
for ( n = 0; n < max_size && \
(c = getc( yyin )) != EOF && c != '\n'; ++n ) \
buf[n] = (char) c; \
if ( c == '\n' ) \
buf[n++] = (char) c; \
if ( c == EOF && ferror( yyin ) ) \
YY_FATAL_ERROR( "input in flex scanner failed" ); \
result = n; \
} \
else \
{ \
errno=0; \
while ( (result = fread(buf, 1, max_size, yyin))==0 && ferror(yyin)) \
{ \
if( errno != EINTR) \
{ \
YY_FATAL_ERROR( "input in flex scanner failed" ); \
break; \
} \
errno=0; \
clearerr(yyin); \
} \
}\
\
#endif
/* No semi-colon after return; correct usage is to write "yyterminate();" -
* we don't want an extra ';' after the "return" because that will cause
* some compilers to complain about unreachable statements.
*/
#ifndef yyterminate
#define yyterminate() return YY_NULL
#endif
/* Number of entries by which start-condition stack grows. */
#ifndef YY_START_STACK_INCR
#define YY_START_STACK_INCR 25
#endif
/* Report a fatal error. */
#ifndef YY_FATAL_ERROR
#define YY_FATAL_ERROR(msg) yy_fatal_error( msg )
#endif
/* end tables serialization structures and prototypes */
/* Default declaration of generated scanner - a define so the user can
* easily add parameters.
*/
#ifndef YY_DECL
#define YY_DECL_IS_OURS 1
extern int yylex (void);
#define YY_DECL int yylex (void)
#endif /* !YY_DECL */
/* Code executed at the beginning of each rule, after yytext and yyleng
* have been set up.
*/
#ifndef YY_USER_ACTION
#define YY_USER_ACTION
#endif
/* Code executed at the end of each rule. */
#ifndef YY_BREAK
#define YY_BREAK break;
#endif
#define YY_RULE_SETUP \
YY_USER_ACTION
/** The main scanner function which does all the work.
*/
YY_DECL
{
register yy_state_type yy_current_state;
register char *yy_cp, *yy_bp;
register int yy_act;
#line 8 "wc.l"
#line 641 "wc.c"
if ( !(yy_init) )
{
(yy_init) = 1;
#ifdef YY_USER_INIT
YY_USER_INIT;
#endif
if ( ! (yy_start) )
(yy_start) = 1; /* first start state */
if ( ! yyin )
yyin = stdin;
if ( ! yyout )
yyout = stdout;
if ( ! YY_CURRENT_BUFFER ) {
yyensure_buffer_stack ();
YY_CURRENT_BUFFER_LVALUE =
yy_create_buffer(yyin,YY_BUF_SIZE );
}
yy_load_buffer_state( );
}
while ( 1 ) /* loops until end-of-file is reached */
{
yy_cp = (yy_c_buf_p);
/* Support of yytext. */
*yy_cp = (yy_hold_char);
/* yy_bp points to the position in yy_ch_buf of the start of
* the current run.
*/
yy_bp = yy_cp;
yy_current_state = (yy_start);
yy_match:
do
{
register YY_CHAR yy_c = yy_ec[YY_SC_TO_UI(*yy_cp)];
if ( yy_accept[yy_current_state] )
{
(yy_last_accepting_state) = yy_current_state;
(yy_last_accepting_cpos) = yy_cp;
}
while ( yy_chk[yy_base[yy_current_state] + yy_c] != yy_current_state )
{
yy_current_state = (int) yy_def[yy_current_state];
if ( yy_current_state >= 9 )
yy_c = yy_meta[(unsigned int) yy_c];
}
yy_current_state = yy_nxt[yy_base[yy_current_state] + (unsigned int) yy_c];
++yy_cp;
}
while ( yy_base[yy_current_state] != 6 );
yy_find_action:
yy_act = yy_accept[yy_current_state];
if ( yy_act == 0 )
{ /* have to back up */
yy_cp = (yy_last_accepting_cpos);
yy_current_state = (yy_last_accepting_state);
yy_act = yy_accept[yy_current_state];
}
YY_DO_BEFORE_ACTION;
do_action: /* This label is used only to access EOF actions. */
switch ( yy_act )
{ /* beginning of action switch */
case 0: /* must back up */
/* undo the effects of YY_DO_BEFORE_ACTION */
*yy_cp = (yy_hold_char);
yy_cp = (yy_last_accepting_cpos);
yy_current_state = (yy_last_accepting_state);
goto yy_find_action;
case 1:
YY_RULE_SETUP
#line 10 "wc.l"
{words++; chars += strlen(yytext);}
YY_BREAK
case 2:
/* rule 2 can match eol */
YY_RULE_SETUP
#line 11 "wc.l"
{chars++; lines++;}
YY_BREAK
case 3:
YY_RULE_SETUP
#line 12 "wc.l"
{chars++;}
YY_BREAK
case 4:
YY_RULE_SETUP
#line 14 "wc.l"
ECHO;
YY_BREAK
#line 745 "wc.c"
case YY_STATE_EOF(INITIAL):
yyterminate();
case YY_END_OF_BUFFER:
{
/* Amount of text matched not including the EOB char. */
int yy_amount_of_matched_text = (int) (yy_cp - (yytext_ptr)) - 1;
/* Undo the effects of YY_DO_BEFORE_ACTION. */
*yy_cp = (yy_hold_char);
YY_RESTORE_YY_MORE_OFFSET
if ( YY_CURRENT_BUFFER_LVALUE->yy_buffer_status == YY_BUFFER_NEW )
{
/* We're scanning a new file or input source. It's
* possible that this happened because the user
* just pointed yyin at a new source and called
* yylex(). If so, then we have to assure
* consistency between YY_CURRENT_BUFFER and our
* globals. Here is the right place to do so, because
* this is the first action (other than possibly a
* back-up) that will match for the new input source.
*/
(yy_n_chars) = YY_CURRENT_BUFFER_LVALUE->yy_n_chars;
YY_CURRENT_BUFFER_LVALUE->yy_input_file = yyin;
YY_CURRENT_BUFFER_LVALUE->yy_buffer_status = YY_BUFFER_NORMAL;
}
/* Note that here we test for yy_c_buf_p "<=" to the position
* of the first EOB in the buffer, since yy_c_buf_p will
* already have been incremented past the NUL character
* (since all states make transitions on EOB to the
* end-of-buffer state). Contrast this with the test
* in input().
*/
if ( (yy_c_buf_p) <= &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[(yy_n_chars)] )
{ /* This was really a NUL. */
yy_state_type yy_next_state;
(yy_c_buf_p) = (yytext_ptr) + yy_amount_of_matched_text;
yy_current_state = yy_get_previous_state( );
/* Okay, we're now positioned to make the NUL
* transition. We couldn't have
* yy_get_previous_state() go ahead and do it
* for us because it doesn't know how to deal
* with the possibility of jamming (and we don't
* want to build jamming into it because then it
* will run more slowly).
*/
yy_next_state = yy_try_NUL_trans( yy_current_state );
yy_bp = (yytext_ptr) + YY_MORE_ADJ;
if ( yy_next_state )
{
/* Consume the NUL. */
yy_cp = ++(yy_c_buf_p);
yy_current_state = yy_next_state;
goto yy_match;
}
else
{
yy_cp = (yy_c_buf_p);
goto yy_find_action;
}
}
else switch ( yy_get_next_buffer( ) )
{
case EOB_ACT_END_OF_FILE:
{
(yy_did_buffer_switch_on_eof) = 0;
if ( yywrap( ) )
{
/* Note: because we've taken care in
* yy_get_next_buffer() to have set up
* yytext, we can now set up
* yy_c_buf_p so that if some total
* hoser (like flex itself) wants to
* call the scanner after we return the
* YY_NULL, it'll still work - another
* YY_NULL will get returned.
*/
(yy_c_buf_p) = (yytext_ptr) + YY_MORE_ADJ;
yy_act = YY_STATE_EOF(YY_START);
goto do_action;
}
else
{
if ( ! (yy_did_buffer_switch_on_eof) )
YY_NEW_FILE;
}
break;
}
case EOB_ACT_CONTINUE_SCAN:
(yy_c_buf_p) =
(yytext_ptr) + yy_amount_of_matched_text;
yy_current_state = yy_get_previous_state( );
yy_cp = (yy_c_buf_p);
yy_bp = (yytext_ptr) + YY_MORE_ADJ;
goto yy_match;
case EOB_ACT_LAST_MATCH:
(yy_c_buf_p) =
&YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[(yy_n_chars)];
yy_current_state = yy_get_previous_state( );
yy_cp = (yy_c_buf_p);
yy_bp = (yytext_ptr) + YY_MORE_ADJ;
goto yy_find_action;
}
break;
}
default:
YY_FATAL_ERROR(
"fatal flex scanner internal error--no action found" );
} /* end of action switch */
} /* end of scanning one token */
} /* end of yylex */
/* yy_get_next_buffer - try to read in a new buffer
*
* Returns a code representing an action:
* EOB_ACT_LAST_MATCH -
* EOB_ACT_CONTINUE_SCAN - continue scanning from current position
* EOB_ACT_END_OF_FILE - end of file
*/
static int yy_get_next_buffer (void)
{
register char *dest = YY_CURRENT_BUFFER_LVALUE->yy_ch_buf;
register char *source = (yytext_ptr);
register int number_to_move, i;
int ret_val;
if ( (yy_c_buf_p) > &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[(yy_n_chars) + 1] )
YY_FATAL_ERROR(
"fatal flex scanner internal error--end of buffer missed" );
if ( YY_CURRENT_BUFFER_LVALUE->yy_fill_buffer == 0 )
{ /* Don't try to fill the buffer, so this is an EOF. */
if ( (yy_c_buf_p) - (yytext_ptr) - YY_MORE_ADJ == 1 )
{
/* We matched a single character, the EOB, so
* treat this as a final EOF.
*/
return EOB_ACT_END_OF_FILE;
}
else
{
/* We matched some text prior to the EOB, first
* process it.
*/
return EOB_ACT_LAST_MATCH;
}
}
/* Try to read more data. */
/* First move last chars to start of buffer. */
number_to_move = (int) ((yy_c_buf_p) - (yytext_ptr)) - 1;
for ( i = 0; i < number_to_move; ++i )
*(dest++) = *(source++);
if ( YY_CURRENT_BUFFER_LVALUE->yy_buffer_status == YY_BUFFER_EOF_PENDING )
/* don't do the read, it's not guaranteed to return an EOF,
* just force an EOF
*/
YY_CURRENT_BUFFER_LVALUE->yy_n_chars = (yy_n_chars) = 0;
else
{
yy_size_t num_to_read =
YY_CURRENT_BUFFER_LVALUE->yy_buf_size - number_to_move - 1;
while ( num_to_read <= 0 )
{ /* Not enough room in the buffer - grow it. */
/* just a shorter name for the current buffer */
YY_BUFFER_STATE b = YY_CURRENT_BUFFER_LVALUE;
int yy_c_buf_p_offset =
(int) ((yy_c_buf_p) - b->yy_ch_buf);
if ( b->yy_is_our_buffer )
{
yy_size_t new_size = b->yy_buf_size * 2;
if ( new_size <= 0 )
b->yy_buf_size += b->yy_buf_size / 8;
else
b->yy_buf_size *= 2;
b->yy_ch_buf = (char *)
/* Include room in for 2 EOB chars. */
yyrealloc((void *) b->yy_ch_buf,b->yy_buf_size + 2 );
}
else
/* Can't grow it, we don't own it. */
b->yy_ch_buf = 0;
if ( ! b->yy_ch_buf )
YY_FATAL_ERROR(
"fatal error - scanner input buffer overflow" );
(yy_c_buf_p) = &b->yy_ch_buf[yy_c_buf_p_offset];
num_to_read = YY_CURRENT_BUFFER_LVALUE->yy_buf_size -
number_to_move - 1;
}
if ( num_to_read > YY_READ_BUF_SIZE )
num_to_read = YY_READ_BUF_SIZE;
/* Read in more data. */
YY_INPUT( (&YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[number_to_move]),
(yy_n_chars), num_to_read );
YY_CURRENT_BUFFER_LVALUE->yy_n_chars = (yy_n_chars);
}
if ( (yy_n_chars) == 0 )
{
if ( number_to_move == YY_MORE_ADJ )
{
ret_val = EOB_ACT_END_OF_FILE;
yyrestart(yyin );
}
else
{
ret_val = EOB_ACT_LAST_MATCH;
YY_CURRENT_BUFFER_LVALUE->yy_buffer_status =
YY_BUFFER_EOF_PENDING;
}
}
else
ret_val = EOB_ACT_CONTINUE_SCAN;
if ((yy_size_t) ((yy_n_chars) + number_to_move) > YY_CURRENT_BUFFER_LVALUE->yy_buf_size) {
/* Extend the array by 50%, plus the number we really need. */
yy_size_t new_size = (yy_n_chars) + number_to_move + ((yy_n_chars) >> 1);
YY_CURRENT_BUFFER_LVALUE->yy_ch_buf = (char *) yyrealloc((void *) YY_CURRENT_BUFFER_LVALUE->yy_ch_buf,new_size );
if ( ! YY_CURRENT_BUFFER_LVALUE->yy_ch_buf )
YY_FATAL_ERROR( "out of dynamic memory in yy_get_next_buffer()" );
}
(yy_n_chars) += number_to_move;
YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[(yy_n_chars)] = YY_END_OF_BUFFER_CHAR;
YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[(yy_n_chars) + 1] = YY_END_OF_BUFFER_CHAR;
(yytext_ptr) = &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[0];
return ret_val;
}
/* yy_get_previous_state - get the state just before the EOB char was reached */
static yy_state_type yy_get_previous_state (void)
{
register yy_state_type yy_current_state;
register char *yy_cp;
yy_current_state = (yy_start);
for ( yy_cp = (yytext_ptr) + YY_MORE_ADJ; yy_cp < (yy_c_buf_p); ++yy_cp )
{
register YY_CHAR yy_c = (*yy_cp ? yy_ec[YY_SC_TO_UI(*yy_cp)] : 1);
if ( yy_accept[yy_current_state] )
{
(yy_last_accepting_state) = yy_current_state;
(yy_last_accepting_cpos) = yy_cp;
}
while ( yy_chk[yy_base[yy_current_state] + yy_c] != yy_current_state )
{
yy_current_state = (int) yy_def[yy_current_state];
if ( yy_current_state >= 9 )
yy_c = yy_meta[(unsigned int) yy_c];
}
yy_current_state = yy_nxt[yy_base[yy_current_state] + (unsigned int) yy_c];
}
return yy_current_state;
}
/* yy_try_NUL_trans - try to make a transition on the NUL character
*
* synopsis
* next_state = yy_try_NUL_trans( current_state );
*/
static yy_state_type yy_try_NUL_trans (yy_state_type yy_current_state )
{
register int yy_is_jam;
register char *yy_cp = (yy_c_buf_p);
register YY_CHAR yy_c = 1;
if ( yy_accept[yy_current_state] )
{
(yy_last_accepting_state) = yy_current_state;
(yy_last_accepting_cpos) = yy_cp;
}
while ( yy_chk[yy_base[yy_current_state] + yy_c] != yy_current_state )
{
yy_current_state = (int) yy_def[yy_current_state];
if ( yy_current_state >= 9 )
yy_c = yy_meta[(unsigned int) yy_c];
}
yy_current_state = yy_nxt[yy_base[yy_current_state] + (unsigned int) yy_c];
yy_is_jam = (yy_current_state == 8);
return yy_is_jam ? 0 : yy_current_state;
}
static void yyunput (int c, register char * yy_bp )
{
register char *yy_cp;
yy_cp = (yy_c_buf_p);
/* undo effects of setting up yytext */
*yy_cp = (yy_hold_char);
if ( yy_cp < YY_CURRENT_BUFFER_LVALUE->yy_ch_buf + 2 )
{ /* need to shift things up to make room */
/* +2 for EOB chars. */
register yy_size_t number_to_move = (yy_n_chars) + 2;
register char *dest = &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[
YY_CURRENT_BUFFER_LVALUE->yy_buf_size + 2];
register char *source =
&YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[number_to_move];
while ( source > YY_CURRENT_BUFFER_LVALUE->yy_ch_buf )
*--dest = *--source;
yy_cp += (int) (dest - source);
yy_bp += (int) (dest - source);
YY_CURRENT_BUFFER_LVALUE->yy_n_chars =
(yy_n_chars) = YY_CURRENT_BUFFER_LVALUE->yy_buf_size;
if ( yy_cp < YY_CURRENT_BUFFER_LVALUE->yy_ch_buf + 2 )
YY_FATAL_ERROR( "flex scanner push-back overflow" );
}
*--yy_cp = (char) c;
(yytext_ptr) = yy_bp;
(yy_hold_char) = *yy_cp;
(yy_c_buf_p) = yy_cp;
}
#ifndef YY_NO_INPUT
#ifdef __cplusplus
static int yyinput (void)
#else
static int input (void)
#endif
{
int c;
*(yy_c_buf_p) = (yy_hold_char);
if ( *(yy_c_buf_p) == YY_END_OF_BUFFER_CHAR )
{
/* yy_c_buf_p now points to the character we want to return.
* If this occurs *before* the EOB characters, then it's a
* valid NUL; if not, then we've hit the end of the buffer.
*/
if ( (yy_c_buf_p) < &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[(yy_n_chars)] )
/* This was really a NUL. */
*(yy_c_buf_p) = '\0';
else
{ /* need more input */
yy_size_t offset = (yy_c_buf_p) - (yytext_ptr);
++(yy_c_buf_p);
switch ( yy_get_next_buffer( ) )
{
case EOB_ACT_LAST_MATCH:
/* This happens because yy_g_n_b()
* sees that we've accumulated a
* token and flags that we need to
* try matching the token before
* proceeding. But for input(),
* there's no matching to consider.
* So convert the EOB_ACT_LAST_MATCH
* to EOB_ACT_END_OF_FILE.
*/
/* Reset buffer status. */
yyrestart(yyin );
/*FALLTHROUGH*/
case EOB_ACT_END_OF_FILE:
{
if ( yywrap( ) )
return EOF;
if ( ! (yy_did_buffer_switch_on_eof) )
YY_NEW_FILE;
#ifdef __cplusplus
return yyinput();
#else
return input();
#endif
}
case EOB_ACT_CONTINUE_SCAN:
(yy_c_buf_p) = (yytext_ptr) + offset;
break;
}
}
}
c = *(unsigned char *) (yy_c_buf_p); /* cast for 8-bit char's */
*(yy_c_buf_p) = '\0'; /* preserve yytext */
(yy_hold_char) = *++(yy_c_buf_p);
return c;
}
#endif /* ifndef YY_NO_INPUT */
/** Immediately switch to a different input stream.
* @param input_file A readable stream.
*
* @note This function does not reset the start condition to @c INITIAL .
*/
void yyrestart (FILE * input_file )
{
if ( ! YY_CURRENT_BUFFER ){
yyensure_buffer_stack ();
YY_CURRENT_BUFFER_LVALUE =
yy_create_buffer(yyin,YY_BUF_SIZE );
}
yy_init_buffer(YY_CURRENT_BUFFER,input_file );
yy_load_buffer_state( );
}
/** Switch to a different input buffer.
* @param new_buffer The new input buffer.
*
*/
void yy_switch_to_buffer (YY_BUFFER_STATE new_buffer )
{
/* TODO. We should be able to replace this entire function body
* with
* yypop_buffer_state();
* yypush_buffer_state(new_buffer);
*/
yyensure_buffer_stack ();
if ( YY_CURRENT_BUFFER == new_buffer )
return;
if ( YY_CURRENT_BUFFER )
{
/* Flush out information for old buffer. */
*(yy_c_buf_p) = (yy_hold_char);
YY_CURRENT_BUFFER_LVALUE->yy_buf_pos = (yy_c_buf_p);
YY_CURRENT_BUFFER_LVALUE->yy_n_chars = (yy_n_chars);
}
YY_CURRENT_BUFFER_LVALUE = new_buffer;
yy_load_buffer_state( );
/* We don't actually know whether we did this switch during
* EOF (yywrap()) processing, but the only time this flag
* is looked at is after yywrap() is called, so it's safe
* to go ahead and always set it.
*/
(yy_did_buffer_switch_on_eof) = 1;
}
static void yy_load_buffer_state (void)
{
(yy_n_chars) = YY_CURRENT_BUFFER_LVALUE->yy_n_chars;
(yytext_ptr) = (yy_c_buf_p) = YY_CURRENT_BUFFER_LVALUE->yy_buf_pos;
yyin = YY_CURRENT_BUFFER_LVALUE->yy_input_file;
(yy_hold_char) = *(yy_c_buf_p);
}
/** Allocate and initialize an input buffer state.
* @param file A readable stream.
* @param size The character buffer size in bytes. When in doubt, use @c YY_BUF_SIZE.
*
* @return the allocated buffer state.
*/
YY_BUFFER_STATE yy_create_buffer (FILE * file, int size )
{
YY_BUFFER_STATE b;
b = (YY_BUFFER_STATE) yyalloc(sizeof( struct yy_buffer_state ) );
if ( ! b )
YY_FATAL_ERROR( "out of dynamic memory in yy_create_buffer()" );
b->yy_buf_size = size;
/* yy_ch_buf has to be 2 characters longer than the size given because
* we need to put in 2 end-of-buffer characters.
*/
b->yy_ch_buf = (char *) yyalloc(b->yy_buf_size + 2 );
if ( ! b->yy_ch_buf )
YY_FATAL_ERROR( "out of dynamic memory in yy_create_buffer()" );
b->yy_is_our_buffer = 1;
yy_init_buffer(b,file );
return b;
}
/** Destroy the buffer.
* @param b a buffer created with yy_create_buffer()
*
*/
void yy_delete_buffer (YY_BUFFER_STATE b )
{
if ( ! b )
return;
if ( b == YY_CURRENT_BUFFER ) /* Not sure if we should pop here. */
YY_CURRENT_BUFFER_LVALUE = (YY_BUFFER_STATE) 0;
if ( b->yy_is_our_buffer )
yyfree((void *) b->yy_ch_buf );
yyfree((void *) b );
}
/* Initializes or reinitializes a buffer.
* This function is sometimes called more than once on the same buffer,
* such as during a yyrestart() or at EOF.
*/
static void yy_init_buffer (YY_BUFFER_STATE b, FILE * file )
{
int oerrno = errno;
yy_flush_buffer(b );
b->yy_input_file = file;
b->yy_fill_buffer = 1;
/* If b is the current buffer, then yy_init_buffer was _probably_
* called from yyrestart() or through yy_get_next_buffer.
* In that case, we don't want to reset the lineno or column.
*/
if (b != YY_CURRENT_BUFFER){
b->yy_bs_lineno = 1;
b->yy_bs_column = 0;
}
b->yy_is_interactive = file ? (isatty( fileno(file) ) > 0) : 0;
errno = oerrno;
}
/** Discard all buffered characters. On the next scan, YY_INPUT will be called.
* @param b the buffer state to be flushed, usually @c YY_CURRENT_BUFFER.
*
*/
void yy_flush_buffer (YY_BUFFER_STATE b )
{
if ( ! b )
return;
b->yy_n_chars = 0;
/* We always need two end-of-buffer characters. The first causes
* a transition to the end-of-buffer state. The second causes
* a jam in that state.
*/
b->yy_ch_buf[0] = YY_END_OF_BUFFER_CHAR;
b->yy_ch_buf[1] = YY_END_OF_BUFFER_CHAR;
b->yy_buf_pos = &b->yy_ch_buf[0];
b->yy_at_bol = 1;
b->yy_buffer_status = YY_BUFFER_NEW;
if ( b == YY_CURRENT_BUFFER )
yy_load_buffer_state( );
}
/** Pushes the new state onto the stack. The new state becomes
* the current state. This function will allocate the stack
* if necessary.
* @param new_buffer The new state.
*
*/
void yypush_buffer_state (YY_BUFFER_STATE new_buffer )
{
if (new_buffer == NULL)
return;
yyensure_buffer_stack();
/* This block is copied from yy_switch_to_buffer. */
if ( YY_CURRENT_BUFFER )
{
/* Flush out information for old buffer. */
*(yy_c_buf_p) = (yy_hold_char);
YY_CURRENT_BUFFER_LVALUE->yy_buf_pos = (yy_c_buf_p);
YY_CURRENT_BUFFER_LVALUE->yy_n_chars = (yy_n_chars);
}
/* Only push if top exists. Otherwise, replace top. */
if (YY_CURRENT_BUFFER)
(yy_buffer_stack_top)++;
YY_CURRENT_BUFFER_LVALUE = new_buffer;
/* copied from yy_switch_to_buffer. */
yy_load_buffer_state( );
(yy_did_buffer_switch_on_eof) = 1;
}
/** Removes and deletes the top of the stack, if present.
* The next element becomes the new top.
*
*/
void yypop_buffer_state (void)
{
if (!YY_CURRENT_BUFFER)
return;
yy_delete_buffer(YY_CURRENT_BUFFER );
YY_CURRENT_BUFFER_LVALUE = NULL;
if ((yy_buffer_stack_top) > 0)
--(yy_buffer_stack_top);
if (YY_CURRENT_BUFFER) {
yy_load_buffer_state( );
(yy_did_buffer_switch_on_eof) = 1;
}
}
/* Allocates the stack if it does not exist.
* Guarantees space for at least one push.
*/
static void yyensure_buffer_stack (void)
{
yy_size_t num_to_alloc;
if (!(yy_buffer_stack)) {
/* First allocation is just for 2 elements, since we don't know if this
* scanner will even need a stack. We use 2 instead of 1 to avoid an
* immediate realloc on the next call.
*/
num_to_alloc = 1;
(yy_buffer_stack) = (struct yy_buffer_state**)yyalloc
(num_to_alloc * sizeof(struct yy_buffer_state*)
);
if ( ! (yy_buffer_stack) )
YY_FATAL_ERROR( "out of dynamic memory in yyensure_buffer_stack()" );
memset((yy_buffer_stack), 0, num_to_alloc * sizeof(struct yy_buffer_state*));
(yy_buffer_stack_max) = num_to_alloc;
(yy_buffer_stack_top) = 0;
return;
}
if ((yy_buffer_stack_top) >= ((yy_buffer_stack_max)) - 1){
/* Increase the buffer to prepare for a possible push. */
int grow_size = 8 /* arbitrary grow size */;
num_to_alloc = (yy_buffer_stack_max) + grow_size;
(yy_buffer_stack) = (struct yy_buffer_state**)yyrealloc
((yy_buffer_stack),
num_to_alloc * sizeof(struct yy_buffer_state*)
);
if ( ! (yy_buffer_stack) )
YY_FATAL_ERROR( "out of dynamic memory in yyensure_buffer_stack()" );
/* zero only the new slots.*/
memset((yy_buffer_stack) + (yy_buffer_stack_max), 0, grow_size * sizeof(struct yy_buffer_state*));
(yy_buffer_stack_max) = num_to_alloc;
}
}
/** Setup the input buffer state to scan directly from a user-specified character buffer.
* @param base the character buffer
* @param size the size in bytes of the character buffer
*
* @return the newly allocated buffer state object.
*/
YY_BUFFER_STATE yy_scan_buffer (char * base, yy_size_t size )
{
YY_BUFFER_STATE b;
if ( size < 2 ||
base[size-2] != YY_END_OF_BUFFER_CHAR ||
base[size-1] != YY_END_OF_BUFFER_CHAR )
/* They forgot to leave room for the EOB's. */
return 0;
b = (YY_BUFFER_STATE) yyalloc(sizeof( struct yy_buffer_state ) );
if ( ! b )
YY_FATAL_ERROR( "out of dynamic memory in yy_scan_buffer()" );
b->yy_buf_size = size - 2; /* "- 2" to take care of EOB's */
b->yy_buf_pos = b->yy_ch_buf = base;
b->yy_is_our_buffer = 0;
b->yy_input_file = 0;
b->yy_n_chars = b->yy_buf_size;
b->yy_is_interactive = 0;
b->yy_at_bol = 1;
b->yy_fill_buffer = 0;
b->yy_buffer_status = YY_BUFFER_NEW;
yy_switch_to_buffer(b );
return b;
}
/** Setup the input buffer state to scan a string. The next call to yylex() will
* scan from a @e copy of @a str.
* @param yystr a NUL-terminated string to scan
*
* @return the newly allocated buffer state object.
* @note If you want to scan bytes that may contain NUL values, then use
* yy_scan_bytes() instead.
*/
YY_BUFFER_STATE yy_scan_string (yyconst char * yystr )
{
return yy_scan_bytes(yystr,strlen(yystr) );
}
/** Setup the input buffer state to scan the given bytes. The next call to yylex() will
* scan from a @e copy of @a bytes.
* @param yybytes the byte buffer to scan
* @param _yybytes_len the number of bytes in the buffer pointed to by @a bytes.
*
* @return the newly allocated buffer state object.
*/
YY_BUFFER_STATE yy_scan_bytes (yyconst char * yybytes, yy_size_t _yybytes_len )
{
YY_BUFFER_STATE b;
char *buf;
yy_size_t n;
int i;
/* Get memory for full buffer, including space for trailing EOB's. */
n = _yybytes_len + 2;
buf = (char *) yyalloc(n );
if ( ! buf )
YY_FATAL_ERROR( "out of dynamic memory in yy_scan_bytes()" );
for ( i = 0; i < _yybytes_len; ++i )
buf[i] = yybytes[i];
buf[_yybytes_len] = buf[_yybytes_len+1] = YY_END_OF_BUFFER_CHAR;
b = yy_scan_buffer(buf,n );
if ( ! b )
YY_FATAL_ERROR( "bad buffer in yy_scan_bytes()" );
/* It's okay to grow etc. this buffer, and we should throw it
* away when we're done.
*/
b->yy_is_our_buffer = 1;
return b;
}
#ifndef YY_EXIT_FAILURE
#define YY_EXIT_FAILURE 2
#endif
static void yy_fatal_error (yyconst char* msg )
{
(void) fprintf( stderr, "%s\n", msg );
exit( YY_EXIT_FAILURE );
}
/* Redefine yyless() so it works in section 3 code. */
#undef yyless
#define yyless(n) \
do \
{ \
/* Undo effects of setting up yytext. */ \
int yyless_macro_arg = (n); \
YY_LESS_LINENO(yyless_macro_arg);\
yytext[yyleng] = (yy_hold_char); \
(yy_c_buf_p) = yytext + yyless_macro_arg; \
(yy_hold_char) = *(yy_c_buf_p); \
*(yy_c_buf_p) = '\0'; \
yyleng = yyless_macro_arg; \
} \
while ( 0 )
/* Accessor methods (get/set functions) to struct members. */
/** Get the current line number.
*
*/
int yyget_lineno (void)
{
return yylineno;
}
/** Get the input stream.
*
*/
FILE *yyget_in (void)
{
return yyin;
}
/** Get the output stream.
*
*/
FILE *yyget_out (void)
{
return yyout;
}
/** Get the length of the current token.
*
*/
yy_size_t yyget_leng (void)
{
return yyleng;
}
/** Get the current token.
*
*/
char *yyget_text (void)
{
return yytext;
}
/** Set the current line number.
* @param line_number
*
*/
void yyset_lineno (int line_number )
{
yylineno = line_number;
}
/** Set the input stream. This does not discard the current
* input buffer.
* @param in_str A readable stream.
*
* @see yy_switch_to_buffer
*/
void yyset_in (FILE * in_str )
{
yyin = in_str ;
}
void yyset_out (FILE * out_str )
{
yyout = out_str ;
}
int yyget_debug (void)
{
return yy_flex_debug;
}
void yyset_debug (int bdebug )
{
yy_flex_debug = bdebug ;
}
static int yy_init_globals (void)
{
/* Initialization is the same as for the non-reentrant scanner.
* This function is called from yylex_destroy(), so don't allocate here.
*/
(yy_buffer_stack) = 0;
(yy_buffer_stack_top) = 0;
(yy_buffer_stack_max) = 0;
(yy_c_buf_p) = (char *) 0;
(yy_init) = 0;
(yy_start) = 0;
/* Defined in main.c */
#ifdef YY_STDINIT
yyin = stdin;
yyout = stdout;
#else
yyin = (FILE *) 0;
yyout = (FILE *) 0;
#endif
/* For future reference: Set errno on error, since we are called by
* yylex_init()
*/
return 0;
}
/* yylex_destroy is for both reentrant and non-reentrant scanners. */
int yylex_destroy (void)
{
/* Pop the buffer stack, destroying each element. */
while(YY_CURRENT_BUFFER){
yy_delete_buffer(YY_CURRENT_BUFFER );
YY_CURRENT_BUFFER_LVALUE = NULL;
yypop_buffer_state();
}
/* Destroy the stack itself. */
yyfree((yy_buffer_stack) );
(yy_buffer_stack) = NULL;
/* Reset the globals. This is important in a non-reentrant scanner so the next time
* yylex() is called, initialization will occur. */
yy_init_globals( );
return 0;
}
/*
* Internal utility routines.
*/
#ifndef yytext_ptr
static void yy_flex_strncpy (char* s1, yyconst char * s2, int n )
{
register int i;
for ( i = 0; i < n; ++i )
s1[i] = s2[i];
}
#endif
#ifdef YY_NEED_STRLEN
static int yy_flex_strlen (yyconst char * s )
{
register int n;
for ( n = 0; s[n]; ++n )
;
return n;
}
#endif
void *yyalloc (yy_size_t size )
{
return (void *) malloc( size );
}
void *yyrealloc (void * ptr, yy_size_t size )
{
/* The cast to (char *) in the following accommodates both
* implementations that use char* generic pointers, and those
* that use void* generic pointers. It works with the latter
* because both ANSI C and C++ allow castless assignment from
* any pointer type to void*, and deal with argument conversions
* as though doing an assignment.
*/
return (void *) realloc( (char *) ptr, size );
}
void yyfree (void * ptr )
{
free( (char *) ptr ); /* see yyrealloc() for (char *) cast */
}
#define YYTABLES_NAME "yytables"
#line 14 "wc.l"
main(int argc, char** argv)
{
yylex();
printf("%8d%8d%8d\n", lines, words, chars);
}
最后编译：gcc -owcwc.c -lfl生成可执行程序wc。
执行：./wc < wc.c
输出： 1748 6555 44017
分享到：
发表评论
相关推荐
资源包含flex-2.5.4+bison-2.4.1+mingw，此外包含本人写的测试源码，编译命令及详细过程，另附一些有用的文章pdf，用于编译原理课程学习。详细使用参考文章：...
Visual Studio中创建Flex+Bison项目，源码中包含多个vs2010可编译通过的demo，用win_flex_bison-2.5.18 其中包含《Visual Studio中创建Flex+Bison项目.pdf》学习flex bison入门资料《flex与bison中文版.pdf》
此压缩包中包含flex和bison两个安装程序，是qgis编译所需的两个必备安装包。
原版Flex and Bison，强大的语法分析工具，本书主要用于...想深入的话需要结合项目或分析一些开源软件的实际应用，flex和bison在开源软件中应用还是挺广的，像内核的dts描述文件，iptables的指令语法均是通过其解析的。
flex.exe和bison.exe for windows
编译器
课程设计，附实验报告。使用Flex&Bison;生成的DLL文件用作计算器后端，使用Flask框架和HTML CSS做前端。
Flex和Bison是为编译器和解释器的编程人员特别设计的工具，其前身分别是lex和Yacc，该压缩包中包含了适合于Windows系统的Flex和Bison程序，版本分别是较新的2.5.37和2.7，解压后需要将Flex和Bison的exe文件路径添加...
Flex与Bison使用教程
Linux下的flex+bison1
flex&bison 英文PDF 及随书代码，编译器设计的工具， 可以提高编译器设计的效率。 文件包内还包含了lex&yacc的中文翻译版及其lex与yacc的程序开发者写的手册。
windows操作系统下的flex与bison，合并了flex与bison工具。
win_flex_bison文件 系统下 编译原理课程所需，下载可直接使用
安装gcc必备的安装包，gcc的安装具有非常强的依赖关系，bison是linux内核必须的安装包，这里提供的是rpm包。
Windows下的flex和bison,用于编程辅助
离线安装包，亲测可用
编译原理的词法分析实验，用flex和bison做的，能识别关键字和自定义的变量。包含与之相对应的实验报告。可以直接拿来交给老师的。
win-flex-bison工具，方便、可用。
Flex and bison are tools designed for writers of compilers and interpreters, although they are also useful for many applications that will interest noncompiler writers. Any application that looks for ...
针对linux系统太老，无法在线安装的情况；...执行 flex --version ，bison --version 。如果能活动版本号则说明安装成功 5.去网上找两个符合规则的测试文件，如 flex ceshi.l ;bison -d ceshi.y ，即可生成c代码