Re: Weird error from a very short bash script involving gfortran and flang compile/execution

[Kenneth Wolcott]

Hi Dave;

  Thanks for the debugging info hint...

  Here's my new ./test_it.bash file:

cat -n ./test_it.bash
     1 #!/bin/bash
     2
     3 printf "\nUsing gfortran-mp-14 ...\n"
     4 # gfortran-mp-14 -x none -o ./non_decimal_radices_convert
./non_decimal_radices_convert.f90
     5 stem="./non_decimal_radices_convert"
     6 source="${stem}.f90"
     7 gfortran-mp-14 -g -O0 -fbacktrace -fcheck=all -Wall -x none -o
$stem $source
     8
     9 if [ -f $stem ]; then
    10 $stem
    11 rm $stem
    12 fi
    13
    14 if [ -f ./conversion.mod ]; then
    15    rm ./conversion.mod
    16 fi
    17
    18 printf "\nUsing flang-mp-20...\n"
    19 /opt/local/bin/flang-mp-20 -o $stem $source
    20 if [ -f $stem ]; then
    21 $stem
    22 rm $stem
    23 fi
    24
    25 if [ -f ./conversion.mod ]; then
    26    rm ./conversion.mod
    27 fi

And here's the output:

./test_it.bash

Using gfortran-mp-14 ...
          26

Program received signal SIGBUS: Access to an undefined portion of a
memory object.

Backtrace for this error:
#0  0x104446083 in ???
#1  0x104445357 in ???
#2  0x1850b56a3 in ???

Could not print backtrace: DW_FORM_line_strp out of range in .debug_line at 38
#3  0x104310c67 in ???
#4  0x104310c67 in ???
#5  0x104310cc7 in ???
./test_it.bash: line 12: 97090 Bus error: 10           $stem

Using flang-mp-20...
 26
 1a

Thanks,
Ken
On Fri, Aug 1, 2025 at 2:31 PM Dave Allured - NOAA Affiliate
<dave.allu...@noaa.gov> wrote:
>
> This feels like subscript out of bounds.  Please add standard gfortran 
> debugging options before asking for deeper analysis.  In particular, 
> `-fcheck=all` will check for most subscripts out of bounds, including string 
> indexing.  It will then give intelligent legible diagnostics.
>
>      `gfortran -g -O0 -fbacktrace -fcheck=all -Wall`
>
>
> On Fri, Aug 1, 2025 at 2:59 PM Kenneth Wolcott <kennethwolc...@gmail.com> 
> wrote:
>>
>> Hi;
>>
>> Weird error from a very short bash script involving gfortran and flang
>> compile/execution...
>>
>> I'm trying to compile and execute a Rosetta Code task written in Fortran:
>>
>> https://rosettacode.org/wiki/Non-decimal_radices/Convert#Fortran
>>
>> *****************************
>> Here is my ./test_it.bash script:
>>
>> cat -n ./test_it.bash
>>      1 #!/bin/bash
>>      2
>>      3 printf "\nUsing gfortran-mp-14 ...\n"
>>      4 gfortran-mp-14 -x none -o ./non_decimal_radices_convert
>> ./non_decimal_radices_convert.f90
>>      5 if [ -f ./non_decimal_radices_convert ]; then
>>      6 ./non_decimal_radices_convert
>>      7 rm ./non_decimal_radices_convert
>>      8 fi
>>      9
>>     10 printf "\nUsing flang-mp-20...\n"
>>     11 /opt/local/bin/flang-mp-20 -o ./non_decimal_radices_convert
>> ./non_decimal_radices_convert.f90
>>     12 if [ -f ./non_decimal_radices_convert ]; then
>>     13 ./non_decimal_radices_convert
>>     14 rm ./non_decimal_radices_convert
>>     15 fi
>>
>> *****************************
>> *****************************
>> Here are the results:
>>
>> ./test_it.bash
>>
>> Using gfortran-mp-14 ...
>>           26
>>
>> Program received signal SIGBUS: Access to an undefined portion of a
>> memory object.
>>
>> Backtrace for this error:
>> #0  0x102e520a7
>> #1  0x102e51357
>> #2  0x1850b56a3
>> #3  0x102c7c997
>> #4  0x102c7c997
>> #5  0x102c7c9ef
>> ./test_it.bash: line 8: 93614 Bus error: 10
>> ./non_decimal_radices_convert
>>
>> Using flang-mp-20...
>>  26
>>  1a
>> *****************************
>>
>> Was the executable generated by gfortran still executing when I deleted it?
>>
>> Why is there a difference?
>>
>> Is there a bug here?
>>
>> Thanks,
>> Ken Wolcott