Re: [PATCH 4/5] gdb: print unknown part of flag enum in hex

[Luis Machado <luis dot machado at linaro dot org>]

On 2/13/20 5:30 PM, Simon Marchi wrote:
> When we print the "unknown" part of a flag enum, it is printed in
> decimal.  I think it would be more useful if it was printed in hex, as
> it helps to determine which bits are set more than a decimal value.

Would it be better to mention the offending bit position explicitly? The 
hex value could be displayed along with it as well.

I mean, in both decimal and hex you'd need to do some calculations to 
figure out the bit position anyway. Might as well make it easier for 
developers by displaying the information.

> gdb/ChangeLog:
>
> 	* valprint.c (generic_val_print_enum_1): Print unknown part of
> 	flag enum in hex.
>
> gdb/testsuite/ChangeLog:
>
> 	* gdb.base/printcmds.exp (test_print_enums): Expect hex values
> 	for "unknown".
> ---
>   gdb/testsuite/gdb.base/printcmds.exp | 4 ++--
>   gdb/valprint.c                       | 4 ++--
>   2 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/gdb/testsuite/gdb.base/printcmds.exp b/gdb/testsuite/gdb.base/printcmds.exp
> index 6afb965af066..d6f5c75650bf 100644
> --- a/gdb/testsuite/gdb.base/printcmds.exp
> +++ b/gdb/testsuite/gdb.base/printcmds.exp
> @@ -743,10 +743,10 @@ proc test_print_enums {} {
>       gdb_test "print (enum flag_enum) 0x0" [string_to_regexp " = FE_NONE"]
>   
>       # Print a flag enum with value 0, where no enumerator has value 0.
> -    gdb_test "print flag_enum_without_zero" [string_to_regexp " = (unknown: 0)"]
> +    gdb_test "print flag_enum_without_zero" [string_to_regexp " = (unknown: 0x0)"]
>   
>       # Print a flag enum with unknown bits set.
> -    gdb_test "print (enum flag_enum) 0xf1" [string_to_regexp " = (FE_ONE | unknown: 240)"]
> +    gdb_test "print (enum flag_enum) 0xf1" [string_to_regexp " = (FE_ONE | unknown: 0xf0)"]
>   
>       # Test printing an enum not considered a "flag enum" (because one of its
>       # enumerators has multiple bits set).
> diff --git a/gdb/valprint.c b/gdb/valprint.c
> index 77b9a4993d79..bd21be69e1bf 100644
> --- a/gdb/valprint.c
> +++ b/gdb/valprint.c
> @@ -659,8 +659,8 @@ generic_val_print_enum_1 (struct type *type, LONGEST val,
>   	{
>   	  if (!first)
>   	    fputs_filtered (" | ", stream);
> -	  fputs_filtered ("unknown: ", stream);
> -	  print_longest (stream, 'd', 0, val);
> +	  fputs_filtered ("unknown: 0x", stream);
> +	  print_longest (stream, 'x', 0, val);
>   	}
>   
>         fputs_filtered (")", stream);