Re: [PATCH] [gdb/testsuite] Fix gdb.ada/float-bits.exp for powerpc64le

[Luis Machado <luis.machado@arm.com>]

This change seems to be causing a timeout on aarch64-linux Ubuntu 22.04.

FAIL: gdb.ada/float-bits.exp: maint print architecture (timeout)

# of expected passes            12
# of unexpected failures        1

It is as if the listing of the architecture fields didn't have time to finish.

On 11/30/22 14:00, Tom de Vries via Gdb-patches wrote:
> On powerpc64le-linux, I run into:
> ...
> (gdb) print 16llf#4000921fb54442d18469898cc51701b8#^M
> $9 = <invalid float value>^M
> (gdb) FAIL: gdb.ada/float-bits.exp: print \
>    16llf#4000921fb54442d18469898cc51701b8#
> ...
> 
> The problem is that we're using a hex string for the 128-bit IEEE quad long
> double format, but the actual long double float format is:
> ...
> gdbarch_dump: long_double_format = floatformat_ibm_long_double_little^M
> ...
> 
> Fix this by using the hex string obtained by compiling test.c:
> ...
> long double a = 5.0e+25L;
> ...
> like so:
> ...
> $ gcc -mlittle test.c -c -g
> ...
> and running gdb:
> ...
> $ gdb -q -batch test.o -ex "p /x a"
> $1 = 0xc1e1c000000000004544adf4b7320335
> ...
> and likewise for -mbig:
> ...
> $ gdb -q -batch test.o -ex "p /x a"
> $1 = 0x4544adf4b7320335c1e1c00000000000
> ...
> 
> Tested on powerpc64le-linux.
> 
> I excercised the case of floatformat_ibm_long_double_big by
> using "set endian big" in the test-case.
> 
> Note that for this patch to work correctly, recent commit aaa79cd62b8 ("[gdb]
> Improve printing of float formats") is required.
> 
> PR testsuite/29816
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29816
> ---
>   gdb/testsuite/gdb.ada/float-bits.exp | 28 ++++++++++++++++++++++++++++
>   1 file changed, 28 insertions(+)
> 
> diff --git a/gdb/testsuite/gdb.ada/float-bits.exp b/gdb/testsuite/gdb.ada/float-bits.exp
> index 55a0566580c..921fe36a4bd 100644
> --- a/gdb/testsuite/gdb.ada/float-bits.exp
> +++ b/gdb/testsuite/gdb.ada/float-bits.exp
> @@ -73,12 +73,40 @@ set gdb_long_double_size [float_size "16llf#0#" ]
>   # example, IEEE quad versus i387 long doubles.  Account for that in the
>   # tests below.
>   
> +# Get the used long double format.
> +set long_double_format ""
> +gdb_test_multiple "maint print architecture" "" {
> +    -re "\r\ngdbarch_dump: long_double_format = (\[^\r\n\]*)" {
> +	set long_double_format $expect_out(1,string)
> +	exp_continue
> +    }
> +    -re -wrap "" {
> +	pass $gdb_test_name
> +    }
> +}
> +
>   # Set default values for 128-bit IEEE quad long doubles.
>   set valid_long_double "16llf#4000921fb54442d18469898cc51701b8#"
>   set printed_long_double "3.1415926535897932384626433832795028"
>   set invalid_long_double ""
>   set has_invalid_long_double 0
>   
> +switch -glob $long_double_format {
> +    floatformat_ibm_long_double_* {
> +	set w1 c1e1c00000000000
> +	set w2 4544adf4b7320335
> +	switch $long_double_format {
> +	    floatformat_ibm_long_double_big {
> +		set valid_long_double "16llf#$w2$w1#"
> +	    }
> +	    floatformat_ibm_long_double_little {
> +		set valid_long_double "16llf#$w1$w2#"
> +	    }
> +	}
> +	set printed_long_double "50000000000000000000000000.0"
> +    }
> +}
> +
>   if { [istarget x86_64-*-* ] || [istarget i?86-*-*] } {
>       # i387 long double have invalid values
>       set has_invalid_long_double 1
> 
> base-commit: aaa79cd62b873be672e3163eb267513c97ec4399