Thank you for your insight. I will investigate further and see if I can
find out what is going on.
J'
On Thu, Sep 13, 2018 at 01:33:34PM -0400, Jason Merrill wrote:
Well, that's curious, given that GCC doesn't have that address type either.
Ah, looking closer, I see that we aren't dealing with the EH unwind
information, but rather the normal DWARF unwind information, which
uses
/* The encoding for FDE's in a normal .debug_frame section
depends on the target address size. */
cie->encoding = DW_EH_PE_absptr;
it seems strange that GDB then wants to use one of the other codes as
a proxy for loading a particular number of bytes.
I also notice that the default definition of DWARF2_ADDR_SIZE in GCC
has a comment,
/* The size of addresses as they appear in the Dwarf 2 data.
Some architectures use word addresses to refer to code locations,
but Dwarf 2 info always uses byte addresses. On such machines,
Dwarf 2 addresses need to be larger than the architecture's
pointers. */
#define DWARF2_ADDR_SIZE ((POINTER_SIZE + BITS_PER_UNIT - 1) /
BITS_PER_UNIT)
And many targets with smaller pointers override this in GCC and GAS, e.g.
./gas/config/tc-msp430.h:#define DWARF2_ADDR_SIZE(bfd) 4
./gas/config/tc-s12z.h:#define DWARF2_ADDR_SIZE(bfd) 4
./gas/config/tc-wasm32.h:#define DWARF2_ADDR_SIZE(bfd) 4
./gas/config/tc-xgate.h:#define DWARF2_ADDR_SIZE(bfd) 4
./gas/config/tc-aarch64.c:/* Implement DWARF2_ADDR_SIZE. */
./gas/config/tc-csky.h:#define DWARF2_ADDR_SIZE(bfd) 4
./gas/config/tc-avr.h:#define DWARF2_ADDR_SIZE(bfd) 4
Is this appropriate for your target, as well?
Perhaps GCC should double check that DWARF2_ADDR_SIZE is 2, 4, or 8.
Jason
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