while ($a = 1) emits a warning "Found = in conditional, should be ==".
However, until ($a = 1) does not. The parser breaks down until
(condition) into while (!(condition)), which defeats the check in
S_scalarboolean, since it is looking for a conditional that /is/ an
assignment, but we have a conditional that is a thinly veiled assignment.
A similar bug is [perl #127122]. That bug was fixed by treating
unless (a) {b} else {c} as if (a) {c} else {b}, instead of treating it
as if (!a) {b} else {c}. That approach will not work here.
Instead, the test in S_scalarboolean has been widened. It previously
looked for an OP_SASSIGN with op_first OP_CONST, it now also detects an
OP_NOT surrounding that construct.
Tests for both while() and until() were also added to t/lib/warnings/op.
{
PERL_ARGS_ASSERT_SCALARBOOLEAN;
- if (o->op_type == OP_SASSIGN && cBINOPo->op_first->op_type == OP_CONST
- && !(cBINOPo->op_first->op_flags & OPf_SPECIAL)) {
+ if ((o->op_type == OP_SASSIGN && cBINOPo->op_first->op_type == OP_CONST &&
+ !(cBINOPo->op_first->op_flags & OPf_SPECIAL)) ||
+ (o->op_type == OP_NOT && cUNOPo->op_first->op_type == OP_SASSIGN &&
+ cBINOPx(cUNOPo->op_first)->op_first->op_type == OP_CONST &&
+ !(cBINOPx(cUNOPo->op_first)->op_first->op_flags & OPf_SPECIAL))) {
if (ckWARN(WARN_SYNTAX)) {
const line_t oldline = CopLINE(PL_curcop);
Found = in conditional, should be == at - line 4.
########
# op.c
+# NAME while with assignment as condition
+use warnings 'syntax';
+1 while $a = 0;
+while ($a = 0) {
+ 1;
+}
+EXPECT
+Found = in conditional, should be == at - line 3.
+Found = in conditional, should be == at - line 4.
+########
+# op.c
+# NAME until with assignment as condition
+use warnings 'syntax';
+1 until $a = 1;
+until ($a = 1) {
+ 1;
+}
+EXPECT
+Found = in conditional, should be == at - line 3.
+Found = in conditional, should be == at - line 4.
+########
+# op.c
use warnings 'syntax' ;
@a[3];
@a{3};