Re: [bug-gawk] 'watch' in gawk debugger gives wrong NR

[Joep van Delft]

Hi Arnold,

Only found time to look at what was committed now; sorry for bringing
this to your attention again after such a long time.


Aharon Robbins schreef op 2015-11-28 22:26:
> The strange ordering you're seeing is the result of breakpoints being
> checked before watchpoints. I have changed the code to check 
> watchpoints
> first.  If you can build from the git repo, you will see behavior that
> makes more sense.

This has not been the problem that I am having.  Frankly, and with all
respect, I believe that the watchpoint1 test in its current form is 
wrong.
If the watchpoint on c triggers, I would assert that nr and NR have the
same values, which currently is not the case.

I believe that this is basically the same issue as Hermann had reported
in "gawk debugger omits watchpoint".

Below you can find a `really_ok` file that might show what I
am after.  To generate it, I took a similar approach as Herman: Put a 
bogus
statement at the end of the action block (line 9), which magically 
convinces
the watchpoint to trigger at a more apt moment.

Comparing the output of the debugger with `trace on` leads me to suspect
that if the watchpoint trigger could somehow be hooked into Op_no_op, 
this
minor issue could be resolved.

Kind regards,

Joep


% cat watchpoint1.really_ok
1       #! /usr/bin/gawk -f
2       BEGIN {
3            c = 0
4       }
5
6       /apple/ {
7            nr = NR
8            c++
9            1+1 # <-- New statement added to watchpoint1.awk
10           # printf "[c, NR] = [%s, %s]\n", c, NR
11      }
12
13      END {
14          print c
15      }
Watchpoint 1: c
1: c = untyped variable
2: nr = untyped variable
3: NR = 0
Breakpoint 2 set at file `watchpoint1.awk', line 6
Starting program:
Stopping in Rule ...
Watchpoint 1: c
  Old value: untyped variable
  New value: 0
main() at `watchpoint1.awk':6
6       /apple/ {
1: c = 0
2: nr = untyped variable
3: NR = 1
Breakpoint 2, main() at `watchpoint1.awk':6
6       /apple/ {
1: c = 0
2: nr = untyped variable
3: NR = 1
Breakpoint 2, main() at `watchpoint1.awk':6
6       /apple/ {
1: c = 0
2: nr = untyped variable
3: NR = 2
Watchpoint 1: c
  Old value: 0
  New value: 1
main() at `watchpoint1.awk':9
9            1+1
1: c = 1
2: nr = 2
3: NR = 2
Breakpoint 2, main() at `watchpoint1.awk':6
6       /apple/ {
1: c = 1
2: nr = 2
3: NR = 3
Breakpoint 2, main() at `watchpoint1.awk':6
6       /apple/ {
1: c = 1
2: nr = 2
3: NR = 4
Watchpoint 1: c
  Old value: 1
  New value: 2
main() at `watchpoint1.awk':9
9            1+1
1: c = 2
2: nr = 4
3: NR = 4