On 7 Feb 2025, at 14:17, Jason Merrill wrote:
> On 2/7/25 4:41 AM, Simon Martin wrote:
>> We've been rejecting the following valid code since GCC 4
>>
>> === cut here ===
>> struct A {
>> explicit A (int);
>> operator void* () const;
>> };
>> void foo (const A& x) {
>> auto res = 0 ? x : 0;
>> }
>> int main () {
>> A a{5};
>> foo(a);
>> }
>> === cut here ===
>>
>> The problem is that for COND_EXPR, add_builtin_candidate has an early
>> return if the true and false values are not pointers that does not take
>> null pointer constants into account. This causes to not find any valid
>> conversion, and fail to compile.
>>
>> This patch fixes the condition to also pass if the true/false values are
>> not pointers but null pointer constants, which resolves the PR.
>>
>> Successfully tested on x86_64-pc-linux-gnu. Given this regression's age,
>> I don't think it make much sense to fix it during stage 4 (let me know
>> if you disagree), so OK for GCC16?
>
> This looks safe enough, OK for GCC 15.
Cool, thanks. Merged as r15-7416-g0b2f34ca19edf2.
Simon
