Re: [PATCH][gdb/testsuite] Fix gdb.base/float128.exp with --with-mpfr=no

[Luis Machado via Gdb-patches <gdb-patches@sourceware.org>]

On 12/10/20 9:53 AM, Tom de Vries wrote:
> Hi,
> 
> When configuring gdb using --with-mpfr=no and running test-case
> gdb.base/float128.exp, we run into:
> ...
> FAIL: gdb.base/float128.exp: print large128 (GDB may be missing MPFR support!)
> ...
> 
> Fix this by detecting that gdb was build without mpfr using the show
> configuration command, and changing the FAIL into UNSUPPORTED.
> 
> Tested on x86_64-linux.
> 
> Any comments?

Would it be more convenient to turn this into a reusable check across 
all tests? Something like "supports_128_floats"?

Then again, if only this particular test will use it, it may not be 
worth it.

> 
> Thanks,
> - Tom
> 
> [gdb/testsuite] Fix gdb.base/float128.exp with --with-mpfr=no
> 
> gdb/testsuite/ChangeLog:
> 
> 2020-12-10  Tom de Vries  <tdevries@suse.de>
> 
> 	PR testsuite/26954
> 	* gdb.base/float128.exp: Detect and handle no mprf support.
> 
> ---
>   gdb/testsuite/gdb.base/float128.exp | 23 ++++++++++++++++++++++-
>   1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/gdb/testsuite/gdb.base/float128.exp b/gdb/testsuite/gdb.base/float128.exp
> index 40babcadc1..66f4d89c12 100644
> --- a/gdb/testsuite/gdb.base/float128.exp
> +++ b/gdb/testsuite/gdb.base/float128.exp
> @@ -78,13 +78,34 @@ gdb_test "print f128" ".* = 20\\.375.*" "the value of f128 is changed to 20.375"
>   # Note: If we get "inf" instead of the correct result, we may have run into
>   # an internal overflow.  This typically happens on host platforms without
>   # native IEEE-128 support where GDB was built without MPFR support.
> +
> +set mpfr_supported -1
> +gdb_test_multiple "show configuration" "" {
> +    -wrap -re "--with-mpfr\r\n.*" {
> +       set mpfr_supported 1
> +    }
> +    -wrap -re "--without-mpfr\r\n.*" {
> +       set mpfr_supported 0
> +    }
> +}
> +
>   set test "print large128"
>   gdb_test_multiple "print large128" "$test" {
>       -re ".* = 1\\.18973149535723176508575932662800702e\\+4932.*$gdb_prompt $" {
>   	pass "$test"
>       }
>       -re ".* = inf.*$gdb_prompt $" {
> -	fail "$test (GDB may be missing MPFR support!)"
> +       if { $mpfr_supported == 0 } {
> +	   if { [istarget "s390*-*-*"] || [istarget "powerpc*-*-*"] } {
> +	       # Some of these archs have native 128-bit float support, in
> +	       # which case this should be passing, even without MPFR support.
> +	       fail $test
> +	   } else {
> +	       unsupported "$test (Missing MPFR support)"
> +	   }
> +       } else {
> +           fail $test
> +       }
>       }
>       -re ".*$gdb_prompt $" {
>   	fail "$test"
>