gdb/782: GDB can't find local variables in function with switch

[dks at antrim dot com]

>Number:         782
>Category:       gdb
>Synopsis:       GDB can't find local variables in function with switch
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Oct 02 11:58:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     dks@antrim.com
>Release:        gdb 5.2.90_2002-09-27-cv
>Organization:
>Environment:
Linux eng-1.antrim.com 2.4.17-ext3-2 #12 SMP Thu Jun 13 08:10:56 PDT 2002 i686 unknown
GCC version 2.96
This GDB was configured as "i686-pc-linux-gnu"...
>Description:
For the following testcase, if I break anywhere before the "stringstream liness(input);" line, I cannot print the values of any local variables.  Once I reach the "liness" declaration, I can:

--------------------------------------------------------
(gdb) break gdbbug.C:16
Breakpoint 1 at 0x804aa09: file gdbbug.C, line 16.
(gdb) run
Starting program: /home/dks/gdb_test/gdbbug 

Breakpoint 1, getDataSetInfo () at gdbbug.C:16
16         input = inputBuf;
(gdb) print done
No symbol "done" in current context.
(gdb) print inputBuf
No symbol "inputBuf" in current context.
(gdb) next
20               done = true;
(gdb) print done
No symbol "done" in current context.
(gdb) print inputBuf
No symbol "inputBuf" in current context.
(gdb) next
24         stringstream liness(input);
(gdb) print done
$1 = true
(gdb) print inputBuf
$2 = '\0' <repeats 376 times>, ...
--------------------------------------------------------

The testcase follows.  I compile this with:
  g++ -O0 -g -o gdbbug gdbbug.C

Notes:
 + If I replace the liness declaration with the "int x;"
   declaration, the problem goes away.
 + If I get rid of the switch statement surrounding the
   "done = true;" line, the problem goes away.
 + Replacing the "-g" with "-gstabs", "-gdwarf" or 
   "-gdwarf-2" makes no difference.
 + I've also tried GCC 3.2, but it makes no difference
 + I've also tried GDB 5.2.1, but it makes no difference
---------------------------------------------------------
#include <sstream>

int countNumbers(char *input)
{
   return 1;
}

void getDataSetInfo(void)
{
   bool done;

   char *input;
   char inputBuf[4096];

   done = false;
   input = inputBuf;
   switch(input[0])
   {
      default:
         done = true;
         break;
   }
//   int x;
   std::stringstream liness(input);
   unsigned numElts = countNumbers(input);
   unsigned numLines = 0;
   unsigned totalElts = 0;
}

int main(int argc,char *argv[])
{
   getDataSetInfo();
}
>How-To-Repeat:

>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: