error message for $(( a )) doesn't have location

[andychu]

14.2 Empty variables in arithmetic expressions

The second most type of warnings is this.

$ osh -c 'a=; echo $((a))'
[??? no location ???] warning: Invalid integer constant ''

Originally posted by @akinomyoga in #653 (comment)

[andychu]

BTW this behavior could be relaxed, e.g. hidden behind shopt -s strict_arith. It depends how many programs are broken by it.

But it is probably better to get through the high priority (double star) issues on #653 before working on that.

[andychu]

After fixing the location. I think the EXIT and RETURN need to be turned into associative arrays, not indexed arrays?

$ ~/git/oilshell/oil/bin/osh -O parse_unimplemented
[osh] lisa ~/git/wild/ble.sh$ source out/ble.osh
    ((!fail))
       ^~~~
out/ble.osh:224: warning: Invalid integer constant ''
    ((!fail))
       ^~~~
out/ble.osh:224: warning: Invalid integer constant ''
      _ble_builtin_trap_signames[index]=$name
                                 ^
[ array LValue in out/ble.osh ]:1833: warning: Invalid integer constant 'EXIT'
      _ble_builtin_trap_signames[index]=$name
                                 ^
[ array LValue in out/ble.osh ]:1833: warning: Invalid integer constant 'RETURN'
      builtin printf -v ret '%d' "'${1:$2:1}"
                                       ^~
out/ble.osh:4619: warning: Invalid integer constant ''
      builtin printf -v ret '%d' "'${1:$2:1}"
                                       ^~
out/ble.osh:4619: warning: Invalid integer constant ''
      builtin printf -v ret '%d' "'${1:$2:1}"
                                       ^~
out/ble.osh:4619: warning: Invalid integer constant ''
      builtin printf -v ret '%d' "'${1:$2:1}"
                                       ^~
out/ble.osh:4619: warning: Invalid integer constant ''

[akinomyoga]

After fixing the location. I think the EXIT and RETURN need to be turned into associative arrays, not indexed arrays?

Thank you for the report! But EXIT and RETURN must not appear here in original ble.sh. It seems there are some problems in upstream of the code, which causes the wrong values of $index.

Ah, this is caused by the format difference of trap -l between Bash and Oil. Looking at Oil trap -l outputs, ble.sh considers EXIT to be the value of ERR and RETURN to be the value of DEBUG.

bash$ builtin trap -l
 1) SIGHUP       2) SIGINT       3) SIGQUIT      4) SIGILL       5) SIGTRAP
 6) SIGABRT      7) SIGBUS       8) SIGFPE       9) SIGKILL     10) SIGUSR1
11) SIGSEGV     12) SIGUSR2     13) SIGPIPE     14) SIGALRM     15) SIGTERM
(snip)

osh$ builtin trap -l
   EXIT
   ERR
   RETURN
   DEBUG
 1 HUP
 2 INT
 3 QUIT
(snip)

[andychu]

Fixed: http://www.oilshell.org/blog/2020/03/release-0.8.pre3.html