Re: [PATCH][gdb/exp] Fix assert when adding ptr to imaginary unit

[Tom de Vries <tdevries@suse.de>]

[-- Attachment #1: Type: text/plain, Size: 1878 bytes --]

On 1/29/21 8:04 AM, Tom de Vries wrote:
> On 1/28/21 3:08 PM, Tom Tromey wrote:
>>>>>>> "Tom" == Tom de Vries <tdevries@suse.de> writes:
>>
>> Tom> 2021-01-28  Tom de Vries  <tdevries@suse.de>
>>
>> Tom> 	PR exp/27265
>> Tom> 	* valarith.c (scalar_binop): Don't call complex_binop unless
>> Tom> 	arguments are either complex or can be casted to complex.
>>
>> Thanks for doing this.
>>
>> Tom> +  if ((type1->code () == TYPE_CODE_COMPLEX
>> Tom> +       && (type2->code () == TYPE_CODE_COMPLEX
>> Tom> +	   || type2->code () == TYPE_CODE_INT
>> Tom> +	   || type2->code () == TYPE_CODE_FLT))
>> Tom> +      || ((type2->code () == TYPE_CODE_COMPLEX
>> Tom> +	   && (type1->code () == TYPE_CODE_COMPLEX
>> Tom> +	       || type1->code () == TYPE_CODE_INT
>> Tom> +	       || type1->code () == TYPE_CODE_FLT))))
>> Tom>      return complex_binop (arg1, arg2, op);
>>
>> Maybe it should use is_floating_type || is_integral_type instead?
>> is_scalar_type sounds like it should be right but does something really
>> different instead.  That function looks suspect to me.
>>
>> This approach would still rule out fixed point.  I'm not sure if that's
>> ok to do though.
>>
>> Also weirdly, is_fixed_point_type looks through TYPE_CODE_RANGE (seems
>> reasonable) but is_integral_type does not (seems wrong).
>>
> 
> I managed to create an example using TYPE_CODE_BOOL that used to work
> but was broken by this patch, added it to the tests in the patch.
> 
> I've now gone a different route: instead of trying to narrow down when
> complex_binop can be called, detect the error situation in complex_bin
> and throw an error.
> 
> That avoids speculation about what type is left after promotion.
> Instead, we just check the type after promotion.
> 
> WDYT?

And FWIW, this WIP follow-up patch enables decimal float complex well
enough to do "print (_Decimal32)0 + 5i".

Thanks,
- Tom

[-- Attachment #2: 0005-gdb-exp-Enable-complex-decimal-float.patch --]
[-- Type: text/x-patch, Size: 2096 bytes --]

[gdb/exp] Enable complex decimal float

---
 gdb/gdbtypes.c                           | 2 +-
 gdb/testsuite/gdb.base/complex-parts.exp | 3 ++-
 gdb/valprint.c                           | 4 ++--
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index c736dff2ca8..b618016d427 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -3419,7 +3419,7 @@ bool
 can_create_complex_type (struct type *target_type)
 {
   return (target_type->code () == TYPE_CODE_INT
-	  || target_type->code () == TYPE_CODE_FLT);
+	  || is_floating_type (target_type));
 }
 
 /* Allocate a TYPE_CODE_COMPLEX type structure.  NAME is the type
diff --git a/gdb/testsuite/gdb.base/complex-parts.exp b/gdb/testsuite/gdb.base/complex-parts.exp
index 6385752a2f0..188fbfeab80 100644
--- a/gdb/testsuite/gdb.base/complex-parts.exp
+++ b/gdb/testsuite/gdb.base/complex-parts.exp
@@ -106,7 +106,8 @@ gdb_test "print (_Complex int) (23.75 + 8.88i)" " = 23 \\+ 8i"
 
 set re_reject_arg "Argument to complex arithmetic operation not supported\\."
 gdb_test "print (void *)0 + 5i" $re_reject_arg
-gdb_test "print (_Decimal32)0 + 5i" $re_reject_arg
+
+gdb_test "print (_Decimal32)0 + 5i" "= 0 \\+ 5.000000i"
 
 # Set language to c++.  Avoid warning by not having current frame.
 clean_restart
diff --git a/gdb/valprint.c b/gdb/valprint.c
index 340a329f9d0..36d66058ee7 100644
--- a/gdb/valprint.c
+++ b/gdb/valprint.c
@@ -830,11 +830,11 @@ generic_value_print_complex (struct value *val, struct ui_file *stream,
   fprintf_filtered (stream, "%s", decorations->complex_prefix);
 
   struct value *real_part = value_real_part (val);
-  value_print_scalar_formatted (real_part, options, 0, stream);
+  generic_value_print (real_part, stream, 0, options, decorations);
   fprintf_filtered (stream, "%s", decorations->complex_infix);
 
   struct value *imag_part = value_imaginary_part (val);
-  value_print_scalar_formatted (imag_part, options, 0, stream);
+  generic_value_print (imag_part, stream, 0, options, decorations);
   fprintf_filtered (stream, "%s", decorations->complex_suffix);
 }