# Clarify the flex debug trace by substituting first line of each rule.
# Francois Pinard <
[email protected]>, July 1990.
#
# Rewritten to process correctly \n's in scanner input.
# BEGIN section modified to correct a collection of rules.
# Michal Jaegermann <
[email protected]>, December 1993
#
# Sample usage:
# flex -d PROGRAM.l
# gcc -o PROGRAM PROGRAM.c -lfl
# PROGRAM 2>&1 | gawk -f debflex.awk PROGRAM.l
#
# (VP's note: this script presently does not work with either "old" or
# "new" awk; fixes so it does will be welcome)
BEGIN {
# Insure proper usage.
if (ARGC != 2) {
print "usage: gawk -f debflex.awk FLEX_SOURCE <DEBUG_OUTPUT";
exit (1);
}
# Remove and save the name of flex source.
source = ARGV[1];
ARGC--;
# Swallow the flex source file.
line = 0;
section = 1;
while (getline <source) {
# Count the lines.
line++;
# Count the sections. When encountering section 3,
# break out of the awk BEGIN block.
if (match ($0, /^%%/)) {
section++;
if (section == 3) {
break;
}
}
else {
# Only the lines in section 2 which do not begin in a
# tab or space might be referred to by the flex debug
# trace. Save only those lines.
if (section == 2 && match ($0, /^[^ \t]/)) {
rules[line] = $0;
}
}
}
dashes = "-----------------------------------------------------------";
collect = "";
line = 0;
}
# collect complete rule output from a scanner
$0 !~ /^--/ {
collect = collect "\n" $0;
next;
}
# otherwise we have a new rule - process what we got so far
{
process();
}
# and the same thing if we hit EOF
END {
process();
}
function process() {
# splitting this way we loose some double dashes and
# left parentheses from echoed input - a small price to pay
n = split(collect, field, "\n--|[(]");
# this loop kicks in only when we already collected something
for (i = 1; i <= n; i++) {
if (0 != line) {
# we do not care for traces of newlines.
if (0 == match(field[i], /\"\n+\"[)]/)) {
if (rules[line]) {
text = field[i];
while ( ++i <= n) {
text = text field[i];
}
printf("%s:%d: %-8s -- %s\n",
source, line, text, rules[line]);
}
else {
print;
printf "%s:%d: *** No such rule.\n", source, line;
}
}
line = 0;
break;
}
if ("" != field[i]) {
if ("end of buffer or a NUL)" == field[i]) {
print dashes; # Simplify trace of buffer reloads
continue;
}
if (match(field[i], /accepting rule at line /)) {
# force interpretation of line as a number
line = 0 + substr(field[i], RLENGTH);
continue;
}
# echo everything else
printf("--%s\n", field[i]);
}
}
collect = "\n" $0; # ... and start next trace
}
