Hi,
At the beginning I would like to thank you for the great project Ragel.
It allows us (www.knot-dns.cz) to have realy fast parser for DNS zone files.
But I have recently noticed that there is a small bug in C code
generation with G{0,1,2},
because there is different behaviour between G and T, F modes.
Meaningless and very pruned snippet of code which can demonstrate the
problem:
== test.rl ==
#include <stdlib.h>
#include <stdio.h>
%%{
machine zone_scanner;
newline = '\n';
comment = ';' . (^newline)*;
wchar = [ \t\n;];
sep = ( [ \t]
| (comment? . newline) when { 0 }
)+;
err_line := (^newline)* . newline @{ fgoto main; };
action _text_char_error {
printf("!TXT_ERROR!\n");
fhold; fgoto err_line;
}
text = ^wchar . (alpha $!_text_char_error)+;
main := "$INCLUDE" . sep . text . newline;
}%%
%% write data;
int main(int argc, char **argv)
{
char buffer[4096];
FILE* f;
long numbytes;
f = fopen(argv[1], "r");
fseek(f, 0, SEEK_END);
numbytes = ftell(f);
fseek(f, 0, SEEK_SET);
fread(buffer, 1, numbytes, f);
char *p = buffer;
char *pe = buffer + numbytes;
char *eof = pe;
int stack[16];
int cs = zone_scanner_start;
int top;
%% write exec;
if (cs == zone_scanner_error) {
printf("!MISC_ERROR!\n");
return -1;
}
return 0;
}
== input.txt ==
$INCLUDE ; Missing filename
==========
ragel -T0 test.rl -o testT.c
gcc testT.c -o testT
./testT ./input.txt
!MISC_ERROR!
ragel -G0 test.rl -o testG.c
gcc testG.c -o testG
./testG ./input.txt
!TXT_ERROR!
Here you can see the state machines stop in different states.
Although this problem is marginal in our project, it would be nice if
Ragel is absolute perfect :-)
Best regards,
Dan
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