[Sdcc-user] sdcdb problem - executes if and else ?

[Dafni & R. B. <da...@ho...>]

Dear all,

I encountered another problem with sdcdb (I took the latest version from
CVS)

To reproduce it, I attach four files and a copy of my session:

BE_seria.c and BE_serial.h should look familiar to you, I took them from the
lib and include directories of SDCC and just renamed them and all variables
and functions inside.

1.) build it:

>make
sdcc -c -mmcs51 --model-small --debug   --nogcse --noinvariant --noinduction
 --nojtbound --noloopreverse --no-peep  BE_serial.c
sdcc -mmcs51 --model-small --debug      --nogcse --noinvariant --noinduction
 --nojtbound --noloopreverse --no-peep  serial_test1.c BE_serial.rel

library file /export/usr/local/share/lib/small/libsdcc.lib
library file /export/usr/local/share/lib/small/libint.lib
library file /export/usr/local/share/lib/small/liblong.lib
library file /export/usr/local/share/lib/small/libfloat.lib

2.) run sdcdb

> gmake debug

3.) set breakpoint in serial BE_serial_interrupt_handler and step

(sdcdb) b BE_serial.c:BE_serial_interrupt_handler
Breakpoint 1 at 0x94: file BE_serial.c, line 47.
(sdcdb) run
Starting program
Breakpoint 1, BE_serial_interrupt_handler() at BE_serial.c:47
47      void BE_serial_interrupt_handler(void) interrupt 4 using 1
(sdcdb) s
BE_serial_interrupt_handler () at BE_serial.c:49
49          ES=0;
(sdcdb) s
50          if ( TI )
(sdcdb) s
52                  TI = 0;
(sdcdb) s
53                  if (BE_stx_index_out == BE_stx_index_in )
(sdcdb) s
55                          BE_tx_serial_buffer_empty = 1;
(sdcdb) s
56                          BE_work_flag_buffer_transfered = 1;
(sdcdb) s
60                      SBUF = BE_stx_buffer[BE_stx_index_out++];
(sdcdb) s
63          if ( RI )
(sdcdb) q

If you look at the source code, you'll see, that the line 60 is in an else
and should not be executed if the debugger goes into the if (line 53).

Here is just this code snippet:

 if (BE_stx_index_out == BE_stx_index_in )
 {
    BE_tx_serial_buffer_empty = 1;
    BE_work_flag_buffer_transfered = 1;
 }
 else
 {
    SBUF = BE_stx_buffer[BE_stx_index_out++];
 }

What's happening ??

Could you please help ?

regards,

Robert


Dafni & Robert Berger
Pharmacist & Embedded Systems Engineer
Stratigou Rogakou 24
15125 Polydrosso - Maroussi
Athens
Greece
Tel, Fax.: ++30 1 6847881
email: da...@ho...
http://users.hol.gr/~dafniz/