Re: [PATCH v2] gdb/testsuite: Skip dump ihex for 64-bit address in gdb.base/dump.exp

[Tiezhu Yang <yangtiezhu@loongson.cn>]

On 4/10/23 09:52, Hui Li wrote:
> (1) Description of problem
> 
> In the current code, when execute the following test on LoongArch:
> 
> $make check-gdb TESTS="gdb.base/dump.exp"
> ```
> FAIL: gdb.base/dump.exp: dump array as value, intel hex
> FAIL: gdb.base/dump.exp: dump struct as value, intel hex
> FAIL: gdb.base/dump.exp: dump array as memory, ihex
> FAIL: gdb.base/dump.exp: dump struct as memory, ihex
> 
> ```
> These tests passed on the X86_64,
> 
> (2) Root cause
> 
> On LoongArch, variable intarray address 0x120008068 out of range for IHEX,
> so dump ihex test failed.
> 
> gdb.base/dump.exp has the following code to check 64-bit address
> 
> ```
>   # Check the address of a variable.  If it is bigger than 32-bit,
>   # assume our target has 64-bit addresses that are not supported by SREC,
>   # IHEX and TEKHEX.  We skip those tests then.
>   set max_32bit_address "0xffffffff"
>   set data_address [get_hexadecimal_valueof "&intarray" 0x100000000]
>   if {${data_address} > ${max_32bit_address}} {
>      set is64bitonly "yes"
> }
> ```
> 
> We check the "&intarray" on different target as follow:
> 
> ```
> $gdb gdb/testsuite/outputs/gdb.base/dump/dump
> ...
> (gdb) start
> ...
> 
> On X86_64:
> (gdb) print /x &intarray
> $1 = 0x404060
> 
> On LoongArch:
> (gdb) print /x &intarray
> $1 = 0x120008068
> ```
> The variable address difference here is due to the link script
> of linker.
> 
> ```
> On X86_64:
> $ld --verbose
> ...
> PROVIDE (__executable_start = SEGMENT_START("text-segment", 0x400000));
> . = SEGMENT_START("text-segment", 0x400000) + SIZEOF_HEADERS;
> 
> On LoongArch:
> $ld --verbose
> ...
> PROVIDE (__executable_start = SEGMENT_START("text-segment", 0x120000000));
> . = SEGMENT_START("text-segment", 0x120000000) + SIZEOF_HEADERS;
> 
> ```
> 
> (3) How to fix
> 
> Because 64-bit variable address out of range for IHEX, it's not an
> functional problem for LoongArch. Refer to the handling of 64-bit
> targets in this testsuite, use the "is64bitonly" flag to skip those
> tests for the target has 64-bit addresses.
> 
> Signed-off-by: Hui Li <lihui@loongson.cn>

Tested on LoongArch, pushed.

Thanks,
Tiezhu