On 2017-07-23, at 4:14 PM, John David Anglin wrote:
> Perl_custom_op_get_field (my_perl=0x1e3008, o=0x5aee38, field=XOPe_xop_peep)
> at op.c:14853
> 14853 if (!he && PL_custom_op_names &&
> (gdb)
> 14879 if(field == XOPe_xop_ptr) {
> (gdb)
> 14902 switch(field) {
> (gdb)
> 14884 switch(field) {
Gcc optimizes the two switch statements in Perl_custom_op_get_field() into one.
It appears the
address of xop gets lost when xop points to xop_null.
The attached patch seems to work around the problem compiling op.c. This would
appear to be
a generic gcc bug.
I also removed the hppa optimization hack for compiling op.c. It no longer
seems to work as the
last -O option is -O2. Adrian's optimization work around changed the last
optimization to -O0.
Maybe the patch will also fix the sh build.
Dave
--
John David Anglin dave.ang...@bell.net
Index: perl-5.26.0/op.c
===================================================================
--- perl-5.26.0.orig/op.c
+++ perl-5.26.0/op.c
@@ -14832,6 +14832,7 @@ Perl_custom_op_get_field(pTHX_ const OP
SV *keysv;
HE *he = NULL;
XOP *xop;
+ XOPRETANY any;
static const XOP xop_null = { 0, 0, 0, 0, 0 };
@@ -14874,58 +14875,37 @@ Perl_custom_op_get_field(pTHX_ const OP
else
xop = INT2PTR(XOP *, SvIV(HeVAL(he)));
}
- {
- XOPRETANY any;
- if(field == XOPe_xop_ptr) {
- any.xop_ptr = xop;
- } else {
- const U32 flags = XopFLAGS(xop);
- if(flags & field) {
- switch(field) {
- case XOPe_xop_name:
- any.xop_name = xop->xop_name;
- break;
- case XOPe_xop_desc:
- any.xop_desc = xop->xop_desc;
- break;
- case XOPe_xop_class:
- any.xop_class = xop->xop_class;
- break;
- case XOPe_xop_peep:
- any.xop_peep = xop->xop_peep;
- break;
- default:
- NOT_REACHED; /* NOTREACHED */
- break;
- }
- } else {
- switch(field) {
- case XOPe_xop_name:
- any.xop_name = XOPd_xop_name;
- break;
- case XOPe_xop_desc:
- any.xop_desc = XOPd_xop_desc;
- break;
- case XOPe_xop_class:
- any.xop_class = XOPd_xop_class;
- break;
- case XOPe_xop_peep:
- any.xop_peep = XOPd_xop_peep;
- break;
- default:
- NOT_REACHED; /* NOTREACHED */
- break;
- }
- }
+
+ if(field == XOPe_xop_ptr) {
+ any.xop_ptr = xop;
+ } else {
+ const U32 flags = XopFLAGS(xop);
+ switch(field) {
+ case XOPe_xop_name:
+ any.xop_name = (flags & field) ? xop->xop_name : XOPd_xop_name;
+ break;
+ case XOPe_xop_desc:
+ any.xop_desc = (flags & field) ? xop->xop_desc : XOPd_xop_desc;
+ break;
+ case XOPe_xop_class:
+ any.xop_class = (flags & field) ? xop->xop_class : XOPd_xop_class;
+ break;
+ case XOPe_xop_peep:
+ any.xop_peep = (flags & field) ? xop->xop_peep : XOPd_xop_peep;
+ break;
+ default:
+ NOT_REACHED; /* NOTREACHED */
+ break;
}
- /* On some platforms (HP-UX, IA64) gcc emits a warning for this
function:
- * op.c: In function 'Perl_custom_op_get_field':
- * op.c:...: warning: 'any.xop_name' may be used uninitialized in this
function [-Wmaybe-uninitialized]
- * This is because on those platforms (with -DEBUGGING) NOT_REACHED
- * expands to assert(0), which expands to ((0) ? (void)0 :
- * __assert(...)), and gcc doesn't know that __assert can never
return. */
- return any;
}
+
+ /* On some platforms (HP-UX, IA64) gcc emits a warning for this function:
+ * op.c: In function 'Perl_custom_op_get_field':
+ * op.c:...: warning: 'any.xop_name' may be used uninitialized in this
function [-Wmaybe-uninitialized]
+ * This is because on those platforms (with -DEBUGGING) NOT_REACHED
+ * expands to assert(0), which expands to ((0) ? (void)0 :
+ * __assert(...)), and gcc doesn't know that __assert can never return. */
+ return any;
}
/*
