[tcf-dev] No registers setup in Frame setup from DWARF info

["Lillieskold, Claes" <claes.lillieskold@xxxxxxxxx>]

Hi,

I’m having problem generating a stack frame longer than one.

The problem I’m seeing is in stack_trace.c:trace_stack() where get_next_stack_frame() returns success,

but doesn’t set down.has_reg_data, which leads to only one frame being produced.

If I change the code so that stack crawler (crawl_stack_frame()) is always used to setup ‘down´, I get a full stack.

 

I’m not sure why this happens and have been debugging symbols.elf:get_stack_tracing_info() without

understanding why the number of registers (info->reg_cnt) is zero for the frame.

No exceptions are thrown during the call to get_stack_tracing_info().

 

It seems that the number of registers in the frame are copied from dwarf_stack_trace_regs_cnt,

but this is always zero for me, and when trying to identify where dwarf_stack_trace_regs_cnt could

be set to non-zero, I find the function dwarfframe.c:generate_command(), where calling

functions that can increase dwarf_stack_trace_regs_cnt is never called because reg->rule for

return address register is always zero.

 

    reg = get_reg(&frame_regs, rules.return_address_register);

    if (reg->rule != 0) {

 

Sorry about the imprecise description, but any pointers or suggestions are very welcome.

 

Thanks,

Claes

 

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