On 2020-12-12 5:21 p.m., John David Anglin wrote:
> On 2020-12-12 4:26 p.m., John Paul Adrian Glaubitz wrote:
>> I assume the crash has got something to do how values are packed and unpacked
>> into the SCM object type. I have not been able to find the problem yet
>> myself,
>> unfortunately which is why I am reporting this issue here.
> I see this in scm.h:
>
> /* The 0?: constructions makes sure that the code is never executed, and
> that there is no performance hit. However, the alternative is
> compiled, and does generate a warning when used with the wrong
> pointer type. We use a volatile pointer type to avoid warnings from
> clang.
>
> The Tru64 and ia64-hp-hpux11.23 compilers fail on `case (0?0=0:x)'
> statements, so for them type-checking is disabled. */
> # if defined __DECC || defined __HP_cc
> # define SCM_UNPACK(x) ((scm_t_bits) (x))
> # else
> # define SCM_UNPACK(x) ((scm_t_bits) (0? (*(volatile SCM *)0=(x)): x))
> # endif
Also just before, there is:
/* But as external interface, we define SCM, which may, according to the
desired level of type checking, be defined in several ways. */
#if (SCM_DEBUG_TYPING_STRICTNESS == 2)
typedef union SCM { struct { scm_t_bits n; } n; } SCM;
# define SCM_UNPACK(x) ((x).n.n)
# define SCM_PACK(x) ((SCM) { { (scm_t_bits) (x) } })
#elif (SCM_DEBUG_TYPING_STRICTNESS == 1)
/* This is the default, which provides an intermediate level of compile
time type checking while still resulting in very efficient code. */
typedef struct scm_unused_struct { char scm_unused_field; } *SCM;
The fault on hppa appears to be at strictness 1.
Regards,
Dave
--
John David Anglin dave.ang...@bell.net
