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 . 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 <> 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 <> actions given. To specify an end-of-file action for just the initial state, use <>. - -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. Changes between 2.2 Patch #3 (30Mar90) and 2.2 Patch #2: - fixed bug which caused -I scanners to bomb Changes between 2.2 Patch #2 (27Mar90) and 2.2 Patch #1: - fixed bug writing past end of input buffer in yyunput() - fixed bug detecting NUL's at the end of a buffer Changes between 2.2 Patch #1 (23Mar90) and 2.2 (alpha) release: - Makefile fixes: definition of MAKE variable for systems which don't have it; installation of flexdoc.1 along with flex.1; fixed two bugs which could cause "bigtest" to fail. - flex.skel fix for compiling with g++. - README and flexdoc.1 no longer list an out-of-date BITNET address for contacting me. - minor typos and formatting changes to flex.1 and flexdoc.1. Changes between 2.2 (alpha) release of March '90 and previous release: User-visible: - Full user documentation now available. - Support for 8-bit scanners. - Scanners now accept NUL's. - A facility has been added for dealing with multiple input buffers. - Two manual entries now. One which fully describes flex (rather than just its differences from lex), and the other for quick(er) reference. - A number of changes to bring flex closer into compliance with the latest POSIX lex draft: %t support flex now accepts multiple input files and concatenates them together to form its input previous -c (compress) flag renamed -C do-nothing -c and -n flags added Any indented code or code within %{}'s in section 2 is now copied to the output - yyleng is now a bona fide global integer. - -d debug information now gives the line number of the matched rule instead of which number rule it was from the beginning of the file. - -v output now includes a summary of the flags used to generate the scanner. - unput() and yyrestart() are now globally callable. - yyrestart() no longer closes the previous value of yyin. - C++ support; generated scanners can be compiled with C++ compiler. - Primitive -lfl library added, containing default main() which calls yylex(). A number of routines currently living in the scanner skeleton will probably migrate to here in the future (in particular, yywrap() will probably cease to be a macro and instead be a function in the -lfl library). - Hexadecimal (\x) escape sequences added. - Support for MS-DOS, VMS, and Turbo-C integrated. - The %used/%unused operators have been deprecated. They may go away soon. Other changes: - Makefile enhanced for easier testing and installation. - The parser has been tweaked to detect some erroneous constructions which previously were missed. - Scanner input buffer overflow is now detected. - Bugs with missing "const" declarations fixed. - Out-of-date Minix/Atari patches provided. - Scanners no longer require printf() unless FLEX_DEBUG is being used. - A subtle input() bug has been fixed. - Line numbers for "continued action" rules (those following the special '|' action) are now correct. - unput() bug fixed; had been causing problems porting flex to VMS. - yymore() handling rewritten to fix bug with interaction between yymore() and trailing context. - EOF in actions now generates an error message. - Bug involving -CFe and generating equivalence classes fixed. - Bug which made -CF be treated as -Cf fixed. - Support for SysV tmpnam() added. - Unused #define's for scanner no longer generated. - Error messages which are associated with a particular input line are now all identified with their input line in standard format. - % directives which are valid to lex but not to flex are now ignored instead of generating warnings. - -DSYS_V flag can now also be specified -DUSG for System V compilation. Changes between 2.1 beta-test release of June '89 and previous release: User-visible: - -p flag generates a performance report to stderr. The report consists of comments regarding features of the scanner rules which result in slower scanners. - -b flag generates backtracking information to lex.backtrack. This is a list of scanner states which require backtracking and the characters on which they do so. By adding rules one can remove backtracking states. If all backtracking states are eliminated, the generated scanner will run faster. Backtracking is not yet documented in the manual entry. - Variable trailing context now works, i.e., one can have rules like "(foo)*/[ \t]*bletch". Some trailing context patterns still cannot be properly matched and generate error messages. These are patterns where the ending of the first part of the rule matches the beginning of the second part, such as "zx*/xy*", where the 'x*' matches the 'x' at the beginning of the trailing context. Lex won't get these patterns right either. - Faster scanners. - End-of-file rules. The special rule "<>" indicates actions which are to be taken when an end-of-file is encountered and yywrap() returns non-zero (i.e., indicates no further files to process). See manual entry for example. - The -r (reject used) flag is gone. flex now scans the input for occurrences of the string "REJECT" to determine if the action is needed. It tries to be intelligent about this but can be fooled. One can force the presence or absence of REJECT by adding a line in the first section of the form "%used REJECT" or "%unused REJECT". - yymore() has been implemented. Similarly to REJECT, flex detects the use of yymore(), which can be overridden using "%used" or "%unused". - Patterns like "x{0,3}" now work (i.e., with lower-limit == 0). - Removed '\^x' for ctrl-x misfeature. - Added '\a' and '\v' escape sequences. - \ now works for octal escape sequences; previously \0 was required. - Better error reporting; line numbers are associated with rules. - yyleng is a macro; it cannot be accessed outside of the scanner source file. - yytext and yyleng should not be modified within a flex action. - Generated scanners #define the name FLEX_SCANNER. - Rules are internally separated by YY_BREAK in lex.yy.c rather than break, to allow redefinition. - The macro YY_USER_ACTION can be redefined to provide an action which is always executed prior to the matched rule's action. - yyrestart() is a new action which can be used to restart the scanner after it has seen an end-of-file (a "real" one, that is, one for which yywrap() returned non-zero). It takes a FILE* argument indicating a new file to scan and sets things up so that a subsequent call to yylex() will start scanning that file. - Internal scanner names all preceded by "yy_" - lex.yy.c is deleted if errors are encountered during processing. - Comments may be put in the first section of the input by preceding them with '#'. Other changes: - Some portability-related bugs fixed, in particular for machines with unsigned characters or sizeof( int* ) != sizeof( int ). Also, tweaks for VMS and Microsoft C (MS-DOS), and identifiers all trimmed to be 31 or fewer characters. Shortened file names for dinosaur OS's. Checks for allocating > 64K memory on 16 bit'ers. Amiga tweaks. Compiles using gcc on a Sun-3. - Compressed and fast scanner skeletons merged. - Skeleton header files done away with. - Generated scanner uses prototypes and "const" for __STDC__. - -DSV flag is now -DSYS_V for System V compilation. - Removed all references to FTL language. - Software now covered by BSD Copyright. - flex will replace lex in subsequent BSD releases.