0. 前言
Flex和Bison是用于构建处理结构化输入的程序的工具。它们最初是用于构建编译器的工具，但它们已被证明在许多其他领域都很有用。
在第一章中，我们将首先看一点(但不是太多)它们背后的理论，然后我们将深入研究一些使用它们的例子。
1. 词法分析&解析
早在20世纪50年代，最早的编译器就使用了专门的技术来分析他们正在编译的程序的源代码的语法。在20世纪60年代
这个领域得到了学术界的广泛关注，到20世纪70年代初，语法分析已经成为一个广为人知的领域。
其中一个关键见解是将这项工作分为两个部分：词汇分析（lexical analysis ，也称为词法分析或扫描）和语法分析（syntax analysis，或解析）。
粗略地说，扫描将输入划分为有意义的块，称为tokens，并通过解析找出tokens之间的关系。例如，考虑以下C代码片段：
alpha = beta + gamma ;
扫描仪将其分为标记alpha、等号、beta、加号、gamma和分号。然后解析器确定beta+gamma是一个表达式，并且
表达式被指定给alpha。
1.1 获取Flex和Bison
大多数Linux和BSD系统都将flex和bison作为基本系统的一部分。如果您的系统没有它们，或者有过时的版本，它们都很容易安装。
Flex是一个Sourceforge项目，网址是http://flex.sourceforge.net/。2009年初的当前版本是2.5.35。版本之间的变化通常很小，所以如果它接近0.35，就没有必要更新你的版本，但有些系统仍然使用2.5.4或2.5.4a版本，这是十多年前的版本。
Bison可从http://www.gnu.org/software/bison/获得。2009年初的当前版本是2.4.1。Bison的开发相当活跃，所以值得购买最新版本，看看有什么新功能。例如，版本2.4增加了对Java解析器的支持。BSD用户通常可以使用ports集合安装flex或bison的当前版本。Linux用户可以找到当前的RPMs。如果没有，flex和bison都使用标准的GNU构建过程，所以要安装它们，从网站上下载并解压缩当前的flex和bison tarball，运行 ./configure然后make来构建它们，然后成为超级用户并make install来安装它们。
Flex和bison都依赖于GNU m4宏处理器。Linux和BSD应该都有m4，但如果他们没有，或者他们有一个古老的版本，当前的GNU m4在http://www.gnu.org/software/m4/。
对于Windows用户，bison和flex都包含在可从http://www.cygwin.com/获得的Cygwin Linux仿真环境中。您可以使用它们用Cygwin开发工具或本机Windows开发工具生成的C或c++代码
1.2 正则表达式和扫描
扫描器通常通过查找输入中的字符模式来工作。例如，在C程序中，整型常量是由一个或多个数字组成的字符串，变量名是一个字母后面跟着零个或多个字母或数字，各种操作符是单个字符或字符对。描述这些模式的一种直接方法是正则表达式（regular expressions），通常简称为regex或regexp。这些模式与编辑器ed和vi以及搜索程序egrep用来描述要搜索的文本的模式相同。flex程序基本上由一个regexps列表组成，其中包含了当输入与其中任何一个regexp匹配时的操作指令，即所谓的操作。flex生成的扫描器读取其输入，将输入与所有regexp进行匹配，并对每个匹配执行适当的操作。Flex将所有regexp转换为一种有效的内部形式，使其能够同时针对所有模式匹配输入，因此对于100个模式和一个模式的速度一样快。★
★ 内部形式称为确定性有限自动化(DFA)。幸运的是，在这一点上，您真正需要知道的关于dfa的唯一一件事是它们非常快，而且速度与模式的数量或复杂性无关。
- 第一个flex程序
Unix系统（我指的是Unix-ish系统，包括Linux和bsd）附带了一个单词计数程序，该程序读取文件并报告文件中的行数、单词数和字符数。Flex允许我们用几十行代码编写wc，如例1-1所示。
/* just like Unix wc */
%{
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);
}
上面flex程序的解释：
对于C程序员来说，这个程序的大部分应该看起来很熟悉，因为它的大部分是C语言。一个flex程序由三个部分组成，用%%行分隔。第一部分包含声明和选项设置。第二部分是模式和操作的列表，第三部分是复制到生成的扫描器中的C代码，通常是与操作中的代码相关的小例程。
在声明部分，%{和%}内部的代码被逐字复制到生成的C源文件开头附近。在本例中，它只是为行（lines）、词（words）和字符（characters）设置变量。
在第二部分中，每个模式位于一行的开头，后面是模式匹配时要执行的C代码。C代码可以是一条语句，也可以是用大括号{}括起来的多行块。（每个模式必须从行首开始，因为flex认为任何以空格开头的行都是要复制到生成的C程序中的代码。）
在这个程序中，只有三种模式。第一个, [a-zA-Z]+匹配一个单词。括号中的字符（称为字符类）匹配任何单个大写或小写字母，+号表示匹配前面的一个或多个字符，这里指的是一串字母或一个单词。action代码更新所看到的单词和字符的数量。在任何flex操作中，变量yytext被设置为指向模式刚刚匹配的输入文本。在这种情况下，我们所关心的是它有多少字符，这样我们就可以适当地更新字符数。
第二个模式\n，只匹配一个新行。该操作更新行数和字符（characters）。
最后一个模式是一个点（.），它是任何字符的正则表达式。(类似于在shell脚本中的问号（?）)动作更新字符的数量。这就是我们需要的所有模式。
最后的C代码是一个主程序，它调用yylex() （flex给扫描器例程的名称），然后打印结果。在没有任何其他安排的情况下，扫描器从标准输入读取。我们运行一下。
[root@node164 0430]# flex 2.l
[root@node164 0430]# ls
2.l lex.yy.c
[root@node164 0430]# gcc lex.yy.c -lfl
首先，我们告诉flex翻译我们的程序，按照经典的Unix方式，因为没有错误，所以它翻译了程序，什么也没说。然后我们编译lex.yy.c，它生成的C程序；链接它与flex库，-lfl；运行它；然后输入一点让它计数。似乎有效。
实际的wc程序对单词的定义略有不同，它是一串非空白字符。一旦我们查找了所有的空白字符是什么，我们只需要将匹配单词的行替换为匹配非空白字符字符串的行：
[^ \t\n\r\f\v]+ { words++; chars += strlen(yytext); }
字符类开头的^表示匹配类中字符以外的任何字符，+再次表示匹配前面的一个或多个模式。这展示了flex的优点之一，对模式进行小的更改是很容易的，并让flex担心这些更改会如何影响生成的代码。
附：lex.yy.c程序的源码
#line 2 "lex.yy.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 6
#define YY_FLEX_SUBMINOR_VERSION 4
#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#ifndef SIZE_MAX
#define SIZE_MAX (~(size_t)0)
#endif#endif /* ! C99 */#endif /* ! FLEXINT_H *//* begin standard C++ headers. *//* TODO: this is always defined, so inline it */
#define yyconst const#if defined(__GNUC__) && __GNUC__ >= 3
#define yynoreturn __attribute__((__noreturn__))
#else
#define yynoreturn
#endif/* Returned upon end-of-file. */
#define YY_NULL 0/* Promotes a possibly negative, possibly signed char to an* integer in range [0..255] for use as an array index.*/
#define YY_SC_TO_UI(c) ((YY_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
#ifdef __ia64__
/* On IA-64, the buffer size is 16k, not 8k.* Moreover, YY_BUF_SIZE is 2*YY_READ_BUF_SIZE in the general case.* Ditto for the __ia64__ case accordingly.*/
#define YY_BUF_SIZE 32768
#else
#define YY_BUF_SIZE 16384
#endif /* __ia64__ */
#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;
#endifextern int 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)#define YY_LINENO_REWIND_TO(ptr)/* 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.*/int yy_buf_size;/* Number of characters read into yy_ch_buf, not including EOB* characters.*/int 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 = NULL; /**< 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 int yy_n_chars; /* number of characters read into yy_ch_buf */
int yyleng;/* Points to current character in buffer. */
static char *yy_c_buf_p = NULL;
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 ( const char *yy_str );
YY_BUFFER_STATE yy_scan_bytes ( const char *bytes, int 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 flex_uint8_t YY_CHAR;FILE *yyin = NULL, *yyout = NULL;typedef int yy_state_type;extern int yylineno;
int yylineno = 1;extern char *yytext;
#ifdef yytext_ptr
#undef yytext_ptr
#endif
#define yytext_ptr yytextstatic 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 yynoreturn yy_fatal_error ( const 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 = (int) (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 const flex_int16_t yy_accept[9] ={ 0,0, 0, 5, 3, 2, 1, 1, 0} ;static const YY_CHAR 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 const YY_CHAR yy_meta[4] ={ 0,1, 1, 2} ;static const flex_int16_t yy_base[10] ={ 0,0, 0, 5, 6, 6, 0, 0, 6, 2} ;static const flex_int16_t yy_def[10] ={ 0,8, 1, 8, 8, 8, 9, 9, 0, 8} ;static const flex_int16_t yy_nxt[10] ={ 0,4, 5, 6, 7, 8, 3, 8, 8, 8} ;static const 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 "2.l"
/* just like Unix wc */
#line 3 "2.l"
int chars = 0;
int words = 0;
int lines = 0;
#line 445 "lex.yy.c"
#line 446 "lex.yy.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 *
#endifstatic 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 );int 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#ifndef YY_NO_UNPUTstatic void yyunput ( int c, char *buf_ptr );#endif#ifndef yytext_ptr
static void yy_flex_strncpy ( char *, const char *, int );
#endif#ifdef YY_NEED_STRLEN
static int yy_flex_strlen ( const 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
#ifdef __ia64__
/* On IA-64, the buffer size is 16k, not 8k */
#define YY_READ_BUF_SIZE 16384
#else
#define YY_READ_BUF_SIZE 8192
#endif /* __ia64__ */
#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, (size_t) 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 = '*'; \int 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 = (int) fread(buf, 1, (yy_size_t) 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 1extern 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 /*LINTED*/break;
#endif#define YY_RULE_SETUP \YY_USER_ACTION/** The main scanner function which does all the work.*/
YY_DECL
{yy_state_type yy_current_state;char *yy_cp, *yy_bp;int yy_act;if ( !(yy_init) ){(yy_init) = 1;#ifdef YY_USER_INITYY_USER_INIT;
#endifif ( ! (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( );}{
#line 7 "2.l"#line 665 "lex.yy.c"while ( /*CONSTCOND*/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{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[yy_c];}yy_current_state = yy_nxt[yy_base[yy_current_state] + 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 8 "2.l"
{ words++; chars += strlen(yytext); }YY_BREAK
case 2:
/* rule 2 can match eol */
YY_RULE_SETUP
#line 9 "2.l"
{ chars++; lines++; }YY_BREAK
case 3:
YY_RULE_SETUP
#line 10 "2.l"
{ chars++; }YY_BREAK
case 4:
YY_RULE_SETUP
#line 11 "2.l"
ECHO;YY_BREAK
#line 743 "lex.yy.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_OFFSETif ( 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 user's declarations */
} /* 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)
{char *dest = YY_CURRENT_BUFFER_LVALUE->yy_ch_buf;char *source = (yytext_ptr);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{int 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 ){int new_size = b->yy_buf_size * 2;if ( new_size <= 0 )b->yy_buf_size += b->yy_buf_size / 8;elseb->yy_buf_size *= 2;b->yy_ch_buf = (char *)/* Include room in for 2 EOB chars. */yyrealloc( (void *) b->yy_ch_buf,(yy_size_t) (b->yy_buf_size + 2) );}else/* Can't grow it, we don't own it. */b->yy_ch_buf = NULL;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;}}elseret_val = EOB_ACT_CONTINUE_SCAN;if (((yy_n_chars) + number_to_move) > YY_CURRENT_BUFFER_LVALUE->yy_buf_size) {/* Extend the array by 50%, plus the number we really need. */int 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, (yy_size_t) new_size );if ( ! YY_CURRENT_BUFFER_LVALUE->yy_ch_buf )YY_FATAL_ERROR( "out of dynamic memory in yy_get_next_buffer()" );/* "- 2" to take care of EOB's */YY_CURRENT_BUFFER_LVALUE->yy_buf_size = (int) (new_size - 2);}(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)
{yy_state_type yy_current_state;char *yy_cp;yy_current_state = (yy_start);for ( yy_cp = (yytext_ptr) + YY_MORE_ADJ; yy_cp < (yy_c_buf_p); ++yy_cp ){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[yy_c];}yy_current_state = yy_nxt[yy_base[yy_current_state] + 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 )
{int yy_is_jam;char *yy_cp = (yy_c_buf_p);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[yy_c];}yy_current_state = yy_nxt[yy_base[yy_current_state] + yy_c];yy_is_jam = (yy_current_state == 8);return yy_is_jam ? 0 : yy_current_state;
}#ifndef YY_NO_UNPUTstatic void yyunput (int c, char * yy_bp )
{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. */int number_to_move = (yy_n_chars) + 2;char *dest = &YY_CURRENT_BUFFER_LVALUE->yy_ch_buf[YY_CURRENT_BUFFER_LVALUE->yy_buf_size + 2];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) = (int) 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;
}#endif#ifndef YY_NO_INPUT
#ifdef __cplusplusstatic int yyinput (void)
#elsestatic 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 */int offset = (int) ((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 0;if ( ! (yy_did_buffer_switch_on_eof) )YY_NEW_FILE;
#ifdef __cplusplusreturn yyinput();
#elsereturn 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( (yy_size_t) (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; /* After all that talk, this was set to 1 anyways... */(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. */yy_size_t 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 NULL;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 = (int) (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 = NULL;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 (const char * yystr )
{return yy_scan_bytes( yystr, (int) 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 (const char * yybytes, int _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 = (yy_size_t) (_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
#endifstatic void yynoreturn yy_fatal_error (const char* msg )
{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.* */
int yyget_leng (void)
{return yyleng;
}/** Get the current token.* */char *yyget_text (void)
{return yytext;
}/** Set the current line number.* @param _line_number 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) = NULL;(yy_buffer_stack_top) = 0;(yy_buffer_stack_max) = 0;(yy_c_buf_p) = NULL;(yy_init) = 0;(yy_start) = 0;/* Defined in main.c */
#ifdef YY_STDINITyyin = stdin;yyout = stdout;
#elseyyin = NULL;yyout = NULL;
#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, const char * s2, int n )
{int i;for ( i = 0; i < n; ++i )s1[i] = s2[i];
}
#endif#ifdef YY_NEED_STRLEN
static int yy_flex_strlen (const char * s )
{int n;for ( n = 0; s[n]; ++n );return n;
}
#endifvoid *yyalloc (yy_size_t size )
{return 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 realloc(ptr, size);
}void yyfree (void * ptr )
{free( (char *) ptr ); /* see yyrealloc() for (char *) cast */
}#define YYTABLES_NAME "yytables"#line 11 "2.l"main(int argc, char **argv)
{yylex();printf("%8d%8d%8d\n", lines, words, chars);
}
![ERROR [internal] load metadata for docker.io/library/node:20-alpine](http://pic.xiahunao.cn/ERROR [internal] load metadata for docker.io/library/node:20-alpine)
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的设计与实现-手把手调试搭建)
