Ping! [PATCH]: Tracking and reporting uninitialized variables

[Caroline Tice <ctice@apple.com>]

On May 1, 2007, at 5:14 PM, Caroline Tice wrote:

>
> As part of some work I have been doing on improving debugging of  
> optimized code, I
> have created a GCC patch that tags variables it believes are  
> uninitialized with a new
> Dwarf op (an extension), DW_OP_GNU_uninit.   I have submitted that  
> patch to the
> GCC patches list and am waiting for approval to commit it.   I have  
> also created the
> following gdb patch to recognize the new op and inform the user when  
> a variable
> the user requests to see is uninitialized.
>
> I have tested this patch on some small testcases and I have run the  
> gdb dejagnu
> testsuite with no regressions.  I am new to submitting things to  
> this list, so if there
> is anything else I ought to have done, please let me know (kindly!).
>
> Is this patch okay to commit to gdb?
>
> -- Caroline Tice
> ctice@apple.com
>
>
>
> 2007-05-01  Caroline Tice  <ctice@apple.com>
>
>        * c-valprint.c (c_value_print):  If the var_status field of the
>        value struct is 0, print out "[uninitialized]" before the  
> value.
>        * dwarf2expr.c (add_piece): Make function non-static.
>        (unsigned_address_type): Likewise.
>        (signed_address_type): Likewise.
>        (execute_stack_op): Initialize ctx->var_status field; allow
>        DW_OP_GNU_uninit as legal op following a DW_OP_reg op or a
>        DW_OP_regx op; add case for DW_OP_GNU_uninit and update
>        ctx->var_status appropriately.
>        * dwarf2expr.h (struct dwarf_expr_context): New field,  
> var_status.
>        (unsigned_address_type): Add extern declaration.
>        (signed_address_type): Likewise.
>        (add_piece): Likewise.
>        * dwarf2loc.c (dwarf2_evaluate_loc_desc): Add call to
>        set_var_status.
>        * dwarf2read.c (dwarf_stack_op_name): Add case for  
> DW_OP_GNU_uninit.
>        (decode_locdesc): Add case for DW_OP_GNU_uninit.
>        * value.c (struct value):  New field, var_status.
>        (allocate_value): Initialize new field.
>        (set_var_status): New function.
>        (value_var_status): New function.
>        * value.h (value_var_status): New extern declaration.
>        (set_var_status): Likewise.
>        * include/elf/dwarf2.h: (enum dwarf_location_atom): Add new  
> DW_OP,
>        DW_OP_GNU_uninit.
>
>
> <fsf-gdb-patch.txt>