[dsdp-dd-dev] local variables view modes

[John Cortell <john.cortell@xxxxxxxxxxxxx>]

There is a feature we've developed in our CDT-based debugger that we 
would like to contribute if there is general interest in it.

A function can contain any number of local variables. Typically, not 
all of the variables are necessarily "live" at every point along the 
function code, but often there is a storage representation for each. 
Consider the following simple scenario

void foo()
{
   int var1;
   {
      int var2;
   }
   var1 = 0;   <--- program is stopped here
   int var3 = 0;
}

Our debugger can support  showing "all locals", which means that the 
variables view will display all three local variables (depending on 
the sym information), even though only one is in scope at the stopped 
location (PC). Our debugger also has the ability to show only "live" 
variables, which means that in the above example, it would just show 
var1. Finally, our debugger also has the ability to show only 
variables that are referenced within a few source lines of the 
current PC; here it does a very simple scan (i.e., grep) of the 
source to make that determination (no preprocessor support).

The user can cycle through these modes during a debug session.

Does anyone with a CDT based debugger find this feature useful? 
Distinguishing variables between "all" and "live" requires debugger 
backend involvement. The "near PC" mode does not. We had to enhance 
CDT/CDI to implement this feature. We'd like to contribute this to 
the community and have it be out of our customization domain, but if 
no one else has a need for this, we won't bother trying.

John