Debugging of Flex and Bison

2. Official website and documentation (SourceForge I often encounter an inaccessible situation when using, do it yourself, you know)

1. flex:http://flex.sourceforge.net/

   Document: http://flex.sourceforge.net/manual/
   

2. bison:http://www.gnu.org/software/bison/

   Document: Https://www.gnu.org/software/bison/manual/html_node/index.html

3. The versions I am currently using are: Flex 2.5.37, Bison 3.0.2, yum installation

4. Debug parameters

   As you can see through--HELP, the Flex debug switch-d,bison the debug switch to-T, adding both parameters when generating the code.
   

6. Manually adjust the Bison code, the light switch is not enough, open gram.c, you can see a lot of macro definitions inside are: "if (yydebug)", search "int yydebug;" definition to: "int yydebug = 1;" Another way is to set yydebug nonzero before starting the grammar engine in other files .

   See section: https://www.gnu.org/software/bison/manual/html_node/Tracing.html

8. Scan.c bug fix, I could not compile the file in the version I used, error:

1. in file included from gram.y:14877:0:scan.c: in function  ' Core_yylex ': scan.c:9263:47: error: macro  "fprintf"  requires 3 arguments, but only  2 given     fprintf ( stderr,  "--scanner backing up\n"  );                                                 ^scan.c:9263:5: warning:  statement with no effect [-wunused-value]     fprintf (  stderr,  "--scanner backing up\n"  );     ^scan.c:9266:52:  error: macro  "fprintf"  passed 4 arguments, but takes just 3                (long) yy_rule_linenum[yy_act], yytext );                                                       ^scan.c:9265:5:  warning: statement with no effect [-wunused-value]      fprintf ( stderr,  "--accepting rule at line %ld  (\"%s\ ") \ n",      ^ &NBSP, .....

3. Open the SCAN.C Discovery macro definition:

1. #undef fprintf#define fprintf (file, FMT, msg) fprintf_to_ereport (FMT, msg) static voidfprintf_to_ereport (const char *FMT , const char *msg) {ereport (ERROR, (Errmsg_internal ("%s", msg));}

5. In conflict with the usage of fprintf below, comment out these lines

Debugging of Flex and Bison