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  1. Changes between 2.3 Patch #7 (28Mar91) and 2.3 Patch #6:
  2. - Fixed out-of-bounds array access that caused bad tables
  3. to be produced on machines where the bad reference happened
  4. to yield a 1. This caused problems installing or running
  5. flex on some Suns, in particular.
  6. Changes between 2.3 Patch #6 (29Aug90) and 2.3 Patch #5:
  7. - Fixed a serious bug in yymore() which basically made it
  8. completely broken. Thanks goes to Jean Christophe of
  9. the Nethack development team for finding the problem
  10. and passing along the fix.
  11. Changes between 2.3 Patch #5 (16Aug90) and 2.3 Patch #4:
  12. - An up-to-date version of initscan.c so "make test" will
  13. work after applying the previous patches
  14. Changes between 2.3 Patch #4 (14Aug90) and 2.3 Patch #3:
  15. - Fixed bug in hexadecimal escapes which allowed only digits,
  16. not letters, in escapes
  17. - Fixed bug in previous "Changes" file!
  18. Changes between 2.3 Patch #3 (03Aug90) and 2.3 Patch #2:
  19. - Correction to patch #2 for gcc compilation; thanks goes to
  20. Paul Eggert for catching this.
  21. Changes between 2.3 Patch #2 (02Aug90) and original 2.3 release:
  22. - Fixed (hopefully) headaches involving declaring malloc()
  23. and free() for gcc, which defines __STDC__ but (often) doesn't
  24. come with the standard include files such as <stdlib.h>.
  25. Reordered #ifdef maze in the scanner skeleton in the hope of
  26. getting the declarations right for cfront and g++, too.
  27. - Note that this patch supercedes patch #1 for release 2.3,
  28. which was never announced but was available briefly for
  29. anonymous ftp.
  30. Changes between 2.3 (full) release of 28Jun90 and 2.2 (alpha) release:
  31. User-visible:
  32. - A lone <<EOF>> rule (that is, one which is not qualified with
  33. a list of start conditions) now specifies the EOF action for
  34. *all* start conditions which haven't already had <<EOF>> actions
  35. given. To specify an end-of-file action for just the initial
  36. state, use <INITIAL><<EOF>>.
  37. - -d debug output is now contigent on the global yy_flex_debug
  38. being set to a non-zero value, which it is by default.
  39. - A new macro, YY_USER_INIT, is provided for the user to specify
  40. initialization action to be taken on the first call to the
  41. scanner. This action is done before the scanner does its
  42. own initialization.
  43. - yy_new_buffer() has been added as an alias for yy_create_buffer()
  44. - Comments beginning with '#' and extending to the end of the line
  45. now work, but have been deprecated (in anticipation of making
  46. flex recognize #line directives).
  47. - The funky restrictions on when semi-colons could follow the
  48. YY_NEW_FILE and yyless macros have been removed. They now
  49. behave identically to functions.
  50. - A bug in the sample redefinition of YY_INPUT in the documentation
  51. has been corrected.
  52. - A bug in the sample simple tokener in the documentation has
  53. been corrected.
  54. - The documentation on the incompatibilities between flex and
  55. lex has been reordered so that the discussion of yylineno
  56. and input() come first, as it's anticipated that these will
  57. be the most common source of headaches.
  58. Things which didn't used to be documented but now are:
  59. - flex interprets "^foo|bar" differently from lex. flex interprets
  60. it as "match either a 'foo' or a 'bar', providing it comes at the
  61. beginning of a line", whereas lex interprets it as "match either
  62. a 'foo' at the beginning of a line, or a 'bar' anywhere".
  63. - flex initializes the global "yyin" on the first call to the
  64. scanner, while lex initializes it at compile-time.
  65. - yy_switch_to_buffer() can be used in the yywrap() macro/routine.
  66. - flex scanners do not use stdio for their input, and hence when
  67. writing an interactive scanner one must explictly call fflush()
  68. after writing out a prompt.
  69. - flex scanner can be made reentrant (after a fashion) by using
  70. "yyrestart( yyin );". This is useful for interactive scanners
  71. which have interrupt handlers that long-jump out of the scanner.
  72. - a defense of why yylineno is not supported is included, along
  73. with a suggestion on how to convert scanners which rely on it.
  74. Other changes:
  75. - Prototypes and proper declarations of void routines have
  76. been added to the flex source code, courtesy of Kevin B. Kenny.
  77. - Routines dealing with memory allocation now use void* pointers
  78. instead of char* - see Makefile for porting implications.
  79. - Error-checking is now done when flex closes a file.
  80. - Various lint tweaks were added to reduce the number of gripes.
  81. - Makefile has been further parameterized to aid in porting.
  82. - Support for SCO Unix added.
  83. - Flex now sports the latest & greatest UC copyright notice
  84. (which is only slightly different from the previous one).
  85. - A note has been added to flexdoc.1 mentioning work in progress
  86. on modifying flex to generate straight C code rather than a
  87. table-driven automaton, with an email address of whom to contact
  88. if you are working along similar lines.
  89. Changes between 2.2 Patch #3 (30Mar90) and 2.2 Patch #2:
  90. - fixed bug which caused -I scanners to bomb
  91. Changes between 2.2 Patch #2 (27Mar90) and 2.2 Patch #1:
  92. - fixed bug writing past end of input buffer in yyunput()
  93. - fixed bug detecting NUL's at the end of a buffer
  94. Changes between 2.2 Patch #1 (23Mar90) and 2.2 (alpha) release:
  95. - Makefile fixes: definition of MAKE variable for systems
  96. which don't have it; installation of flexdoc.1 along with
  97. flex.1; fixed two bugs which could cause "bigtest" to fail.
  98. - flex.skel fix for compiling with g++.
  99. - README and flexdoc.1 no longer list an out-of-date BITNET address
  100. for contacting me.
  101. - minor typos and formatting changes to flex.1 and flexdoc.1.
  102. Changes between 2.2 (alpha) release of March '90 and previous release:
  103. User-visible:
  104. - Full user documentation now available.
  105. - Support for 8-bit scanners.
  106. - Scanners now accept NUL's.
  107. - A facility has been added for dealing with multiple
  108. input buffers.
  109. - Two manual entries now. One which fully describes flex
  110. (rather than just its differences from lex), and the
  111. other for quick(er) reference.
  112. - A number of changes to bring flex closer into compliance
  113. with the latest POSIX lex draft:
  114. %t support
  115. flex now accepts multiple input files and concatenates
  116. them together to form its input
  117. previous -c (compress) flag renamed -C
  118. do-nothing -c and -n flags added
  119. Any indented code or code within %{}'s in section 2 is
  120. now copied to the output
  121. - yyleng is now a bona fide global integer.
  122. - -d debug information now gives the line number of the
  123. matched rule instead of which number rule it was from
  124. the beginning of the file.
  125. - -v output now includes a summary of the flags used to generate
  126. the scanner.
  127. - unput() and yyrestart() are now globally callable.
  128. - yyrestart() no longer closes the previous value of yyin.
  129. - C++ support; generated scanners can be compiled with C++ compiler.
  130. - Primitive -lfl library added, containing default main()
  131. which calls yylex(). A number of routines currently living
  132. in the scanner skeleton will probably migrate to here
  133. in the future (in particular, yywrap() will probably cease
  134. to be a macro and instead be a function in the -lfl library).
  135. - Hexadecimal (\x) escape sequences added.
  136. - Support for MS-DOS, VMS, and Turbo-C integrated.
  137. - The %used/%unused operators have been deprecated. They
  138. may go away soon.
  139. Other changes:
  140. - Makefile enhanced for easier testing and installation.
  141. - The parser has been tweaked to detect some erroneous
  142. constructions which previously were missed.
  143. - Scanner input buffer overflow is now detected.
  144. - Bugs with missing "const" declarations fixed.
  145. - Out-of-date Minix/Atari patches provided.
  146. - Scanners no longer require printf() unless FLEX_DEBUG is being used.
  147. - A subtle input() bug has been fixed.
  148. - Line numbers for "continued action" rules (those following
  149. the special '|' action) are now correct.
  150. - unput() bug fixed; had been causing problems porting flex to VMS.
  151. - yymore() handling rewritten to fix bug with interaction
  152. between yymore() and trailing context.
  153. - EOF in actions now generates an error message.
  154. - Bug involving -CFe and generating equivalence classes fixed.
  155. - Bug which made -CF be treated as -Cf fixed.
  156. - Support for SysV tmpnam() added.
  157. - Unused #define's for scanner no longer generated.
  158. - Error messages which are associated with a particular input
  159. line are now all identified with their input line in standard
  160. format.
  161. - % directives which are valid to lex but not to flex are
  162. now ignored instead of generating warnings.
  163. - -DSYS_V flag can now also be specified -DUSG for System V
  164. compilation.
  165. Changes between 2.1 beta-test release of June '89 and previous release:
  166. User-visible:
  167. - -p flag generates a performance report to stderr. The report
  168. consists of comments regarding features of the scanner rules
  169. which result in slower scanners.
  170. - -b flag generates backtracking information to lex.backtrack.
  171. This is a list of scanner states which require backtracking
  172. and the characters on which they do so. By adding rules
  173. one can remove backtracking states. If all backtracking states
  174. are eliminated, the generated scanner will run faster.
  175. Backtracking is not yet documented in the manual entry.
  176. - Variable trailing context now works, i.e., one can have
  177. rules like "(foo)*/[ \t]*bletch". Some trailing context
  178. patterns still cannot be properly matched and generate
  179. error messages. These are patterns where the ending of the
  180. first part of the rule matches the beginning of the second
  181. part, such as "zx*/xy*", where the 'x*' matches the 'x' at
  182. the beginning of the trailing context. Lex won't get these
  183. patterns right either.
  184. - Faster scanners.
  185. - End-of-file rules. The special rule "<<EOF>>" indicates
  186. actions which are to be taken when an end-of-file is
  187. encountered and yywrap() returns non-zero (i.e., indicates
  188. no further files to process). See manual entry for example.
  189. - The -r (reject used) flag is gone. flex now scans the input
  190. for occurrences of the string "REJECT" to determine if the
  191. action is needed. It tries to be intelligent about this but
  192. can be fooled. One can force the presence or absence of
  193. REJECT by adding a line in the first section of the form
  194. "%used REJECT" or "%unused REJECT".
  195. - yymore() has been implemented. Similarly to REJECT, flex
  196. detects the use of yymore(), which can be overridden using
  197. "%used" or "%unused".
  198. - Patterns like "x{0,3}" now work (i.e., with lower-limit == 0).
  199. - Removed '\^x' for ctrl-x misfeature.
  200. - Added '\a' and '\v' escape sequences.
  201. - \<digits> now works for octal escape sequences; previously
  202. \0<digits> was required.
  203. - Better error reporting; line numbers are associated with rules.
  204. - yyleng is a macro; it cannot be accessed outside of the
  205. scanner source file.
  206. - yytext and yyleng should not be modified within a flex action.
  207. - Generated scanners #define the name FLEX_SCANNER.
  208. - Rules are internally separated by YY_BREAK in lex.yy.c rather
  209. than break, to allow redefinition.
  210. - The macro YY_USER_ACTION can be redefined to provide an action
  211. which is always executed prior to the matched rule's action.
  212. - yyrestart() is a new action which can be used to restart
  213. the scanner after it has seen an end-of-file (a "real" one,
  214. that is, one for which yywrap() returned non-zero). It takes
  215. a FILE* argument indicating a new file to scan and sets
  216. things up so that a subsequent call to yylex() will start
  217. scanning that file.
  218. - Internal scanner names all preceded by "yy_"
  219. - lex.yy.c is deleted if errors are encountered during processing.
  220. - Comments may be put in the first section of the input by preceding
  221. them with '#'.
  222. Other changes:
  223. - Some portability-related bugs fixed, in particular for machines
  224. with unsigned characters or sizeof( int* ) != sizeof( int ).
  225. Also, tweaks for VMS and Microsoft C (MS-DOS), and identifiers all
  226. trimmed to be 31 or fewer characters. Shortened file names
  227. for dinosaur OS's. Checks for allocating > 64K memory
  228. on 16 bit'ers. Amiga tweaks. Compiles using gcc on a Sun-3.
  229. - Compressed and fast scanner skeletons merged.
  230. - Skeleton header files done away with.
  231. - Generated scanner uses prototypes and "const" for __STDC__.
  232. - -DSV flag is now -DSYS_V for System V compilation.
  233. - Removed all references to FTL language.
  234. - Software now covered by BSD Copyright.
  235. - flex will replace lex in subsequent BSD releases.