Breaking on C labels?

[Joel Brobecker <brobecker at adacore dot com>]

Hello,

A customer asked us a question about the ability of breaking on labels
inside C code. Consider for instance:

        void
        procedure foo (void)
        {
           [...]
        error_handler:
           [...]
        }

The customer asked if it was possible to break at the error_handler
label. We are helping them with finding alternative solutions, but
I still did a bit of researching...

I discovered without much surprise that DWARF does indeed have provision
for labels (DW_TAG_label). However, I also noticed that GCC already
generates the associated DIEs. We actually even process them. However,
all my attempts in trying to reference them from the debugger failed.
I tried "break error_handler", or more simply "p error_handler", etc.

Did we ever make any attempt in implementing this sort of functionality
in the past?

Looking at the source code, I found in new_symbol ():

        case DW_TAG_label:
          attr = dwarf2_attr (die, DW_AT_low_pc, cu);
          if (attr)
            {
              SYMBOL_VALUE_ADDRESS (sym) = DW_ADDR (attr) + baseaddr;
            }
          SYMBOL_CLASS (sym) = LOC_LABEL;
          break;

So we setup the symbol, but we don't add to any of our symbol lists...
I am left wondering what it is that we'll be doing with this symbol.

Thanks,
-- 
Joel, curious