changes

生成C++的词法/语法分析的Flex语法分析器

Changes between 2.3.8-7 and 2.3.8-8
	- flexskel.{cc,h} flex++.1.dman destructor does call YY_DELETE_BUFFER, and %define DESTRUCTOR_CODE. memory leakage avoided !
	- (same files)flexskel.{cc,h} flex++.1.dman %define CURRENT_BUFFER created to rename YY_CURRENT_BUFFER. there is no more yy_current_buffer member, but just the YY_CURRENT_BUFFER by default or YY_@_CURRENT_BUFFER.
Changes between 2.3.8-6 and 2.3.8-7
	- flexskel.cc flexskel.h flex++.1.dman: support iostream
	- samples show IOSTREAM calpability
Changes between 3.0.3 and 2.3.8-6
	- scan.l : add a header_skeleton_out() in rule ^"%%".* in
        order to include header skeleton section between section 1 and 2
Changes between 3.0.3 and 2.3.8-5
	- sent to CUG 
Changes between 3.0.3 and 2.3.8-4
	- main.c: change version name to (flex version-flex++ release), ie flex++-2.3.8-4
        - flexskel.cc : add #define YY_USE_CLASS if C++  line 39
        - main.cc :  line 876. accept the digits in #ifndef guard symbol name, instead of mapping them to underscore.
Changes between 3.0.2 and 3.0.3 
	- regenerated scan.c (and initscan.c) to use newest skeleton
	- Makefile:make test does not fail if diff fail, because it is always
         the case. The #line directives are always differents .
	- makefile: mail big test will fail on fast table, because there
	 is variable trailing context. don't worry
	- Notes.txt : creation of this file, with mail transaction
Version 3.0.2 sent to compiler.iecc.com
Changes between 3.0.1 and 3.0.2
	- flexskel.cc : remove include osfcn.h for dos
	- flexskel.cc : define _MSDOS if MSDOS defined or __MSDOS__
	- flexskel.cc : dquote remaining at end of line in debug code only. corrected.
	- main.c : mismatch between FILE* and char* when searching skeletons in getenv("INIT") on DOS.corrected.
	- main.c : mismatch that make .cpp suffix not to be replaced by .h in header. corrected.
	- flex++.1.dman : class declaration added in man page.
Changes between 3.0.0 and 3.0.1
	- use Patch #8 (21Feb93) of flex 2.3.8:
	- flex++.1.dman : remove stupid reference to %define PARSE_PARAM...
> Changes between 2.3 Patch #8 (21Feb93) and 2.3 Patch #7:
> 
> 	- Fixed bugs in dynamic memory allocation leading to grievous
> 	  fencepost problems when generating large scanners.
> 	- Fixed bug causing infinite loops on character classes with 8-bit
> 	  characters in them.
> 	- Fixed bug in matching repetitions with a lower bound of 0.
> 	- Fixed bug in scanning NUL characters using an "interactive" scanner.
> 	- Fixed bug in using yymore() at the end of a file.
> 	- Fixed bug in misrecognizing rules with variable trailing context.
> 	- Fixed bug compiling flex on Suns using gcc 2.
> 	- Fixed bug in not recognizing that input files with the character
> 	  ASCII 128 in them require the -8 flag.
> 	- Fixed bug that could cause an infinite loop writing out
> 	  error messages.
> 	- Fixed bug in not recognizing old-style lex % declarations if
> 	  followed by a tab instead of a space.
> 	- Fixed potential crash when flex terminated early (usually due
> 	  to a bad flag) and the -v flag had been given.
> 	- Added some missing declarations of void functions.
> 	- Changed to only use '\a' for __STDC__ compilers.
> 	- Updated mailing addresses.
> 
> 
Changes between 3.0.0 and 2.3.7 by [e-mail]
	- many things changed !!!
	- header can be generated
	- %header{ in section 1 and 2 
	- %define in section 1 
	- %name in section 1 
	- use 2 skeletons header and code flexskel.cc and flexskel.h
	- if no header generated, merge with code, else #include 
	- -g option change the name of #include 
	- -h option activate header generation and choose name 
	- -o option choose output name 
	- -h without name use lex.yy.h or the output (-o) appended/replaced with .h suffix. 
	- -H option change header skeleton 
	- skeleton support C++, and generate classes
	- many things can be changed by %define (names...)
	- compatibility with older version,  if no header generated.
	- C++ comment supported
	- #line automaticaly added in skeleton
	- coherent with bison++ version proposed by same author
Changes between 2.3 Patch #7 (28Mar91) and 2.3 Patch #6:

	- Fixed out-of-bounds array access that caused bad tables
	  to be produced on machines where the bad reference happened
	  to yield a 1.  This caused problems installing or running
	  flex on some Suns, in particular.


Changes between 2.3 Patch #6 (29Aug90) and 2.3 Patch #5:

	- Fixed a serious bug in yymore() which basically made it
	  completely broken.  Thanks goes to Jean Christophe of
	  the Nethack development team for finding the problem
	  and passing along the fix.


Changes between 2.3 Patch #5 (16Aug90) and 2.3 Patch #4:

	- An up-to-date version of initscan.c so "make test" will
	  work after applying the previous patches


Changes between 2.3 Patch #4 (14Aug90) and 2.3 Patch #3:

	- Fixed bug in hexadecimal escapes which allowed only digits,
	  not letters, in escapes
	- Fixed bug in previous "Changes" file!


Changes between 2.3 Patch #3 (03Aug90) and 2.3 Patch #2:

	- Correction to patch #2 for gcc compilation; thanks goes to
	  Paul Eggert for catching this.


Changes between 2.3 Patch #2 (02Aug90) and original 2.3 release:

	- Fixed (hopefully) headaches involving declaring malloc()
	  and free() for gcc, which defines __STDC__ but (often) doesn't
	  come with the standard include files such as <stdlib.h>.
	  Reordered #ifdef maze in the scanner skeleton in the hope of
	  getting the declarations right for cfront and g++, too.

	- Note that this patch supercedes patch #1 for release 2.3,
	  which was never announced but was available briefly for
	  anonymous ftp.


Changes between 2.3 (full) release of 28Jun90 and 2.2 (alpha) release:

    User-visible:

	- A lone <<EOF>> rule (that is, one which is not qualified with
	  a list of start conditions) now specifies the EOF action for
	  *all* start conditions which haven't already had <<EOF>> actions
	  given.  To specify an end-of-file action for just the initial
	  state, use <INITIAL><<EOF>>.

	- -d debug output is now contigent on the global yy_flex_debug
	  being set to a non-zero value, which it is by default.

	- A new macro, YY_USER_INIT, is provided for the user to specify
	  initialization action to be taken on the first call to the
	  scanner.  This action is done before the scanner does its
	  own initialization.

	- yy_new_buffer() has been added as an alias for yy_create_buffer()

	- Comments beginning with '#' and extending to the end of the line
	  now work, but have been deprecated (in anticipation of making
	  flex recognize #line directives).

	- The funky restrictions on when semi-colons could follow the
	  YY_NEW_FILE and yyless macros have been removed.  They now
	  behave identically to functions.

	- A bug in the sample redefinition of YY_INPUT in the documentation
	  has been corrected.

	- A bug in the sample simple tokener in the documentation has
	  been corrected.

	- The documentation on the incompatibilities between flex and
	  lex has been reordered so that the discussion of yylineno
	  and input() come first, as it's anticipated that these will
	  be the most common source of headaches.


    Things which didn't used to be documented but now are:

	- flex interprets "^foo|bar" differently from lex.  flex interprets
	  it as "match either a 'foo' or a 'bar', providing it comes at the
	  beginning of a line", whereas lex interprets it as "match either
	  a 'foo' at the beginning of a line, or a 'bar' anywhere".

	- flex initializes the global "yyin" on the first call to the
	  scanner, while lex initializes it at compile-time.

	- yy_switch_to_buffer() can be used in the yywrap() macro/routine.

	- flex scanners do not use stdio for their input, and hence when
	  writing an interactive scanner one must explictly call fflush()
	  after writing out a prompt.

	- flex scanner can be made reentrant (after a fashion) by using
	  "yyrestart( yyin );".  This is useful for interactive scanners
	  which have interrupt handlers that long-jump out of the scanner.

	- a defense of why yylineno is not supported is included, along
	  with a suggestion on how to convert scanners which rely on it.


    Other changes:

	- Prototypes and proper declarations of void routines have
	  been added to the flex source code, courtesy of Kevin B. Kenny.

	- Routines dealing with memory allocation now use void* pointers
	  instead of char* - see Makefile for porting implications.

	- Error-checking is now done when flex closes a file.

	- Various lint tweaks were added to reduce the number of gripes.

	- Makefile has been further parameterized to aid in porting.

	- Support for SCO Unix added.

	- Flex now sports the latest & greatest UC copyright notice
	  (which is only slightly different from the previous one).

	- A note has been added to flexdoc.1 mentioning work in progress
	  on modifying flex to generate straight C code rather than a
	  table-driven automaton, with an email address of whom to contact
	  if you are working along similar lines.