> Ok, I applied a fix for PR52134 and am preparing a fix for PR52578.
> It seems we might not be able to rely on
>
> tree maxsize = size_diffop (TYPE_SIZE_UNIT (DECL_CONTEXT (field)),
> DECL_FIELD_OFFSET (repr));
> gcc_assert (host_integerp (maxsize, 1));
>
> but at least until we get a testcase that shows so I won't add
> (unexercised) code that handles it. Eventually we'd need to treat
> tail-padding specially for some languages anyway, via a new langhook.
This caused 3 classes of problems in Ada:
1. failure of the above assertion (pack7.ads)
2. ICE in tree_low_cst (pack16.adb, pack16_pkg.ads)
3. miscompilation (to be dealt with later).
1. and 2. appear to come from variable-sized fields (and 3. from record types
with variant part). Testcases attached, they can be installed as:
gnat.dg/pack16.adb
gnat.dg/pack16_pkg.ads
gnat.dg/specs/pack7.ads
in the testsuite.
--
Eric Botcazou
-- { dg-do compile }
-- { dg-options "-gnatws" }
with Pack16_Pkg; use Pack16_Pkg;
procedure Pack16 is
type Sample_Table_T is array (1 .. N) of Integer;
type Clock_T is record
N_Ticks : Integer := 0;
end record;
type Sampling_Descriptor_T is record
Values : Sample_Table_T;
Valid : Boolean;
Tstamp : Clock_T;
end record;
pragma Pack (Sampling_Descriptor_T);
Sampling_Data : Sampling_Descriptor_T;
begin
null;
end;
package Pack16_Pkg is
N : Natural := 16;
end Pack16_Pkg;
-- { dg-do compile }
package Pack7 is
type R (D : Natural) is record
S : String (1 .. D);
N : Natural;
B : Boolean;
end record;
for R'Alignment use 4;
pragma Pack (R);
end Pack7;
