https://gcc.gnu.org/bugzilla/show_bug.cgi?id=127411
Bug ID: 127411
Summary: Compilation errors with nonprimitive register-mapped
variables in C++ mode
Product: gcc
Version: 17.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: pskocik at gmail dot com
Target Milestone: ---
Example code:
typedef struct Long { long _; } Long; /*nonprimitive type*/
int main(void){
(void)({ register long x asm("rdx"); asm volatile("":"+r"(x)); x;}); //✓
(void)({ register Long x asm("rdx"); asm volatile("":"+r"(x)); x;}); //✗
g++ :(
#if __cplusplus
(void)[]{ register long x asm("rdx"); asm volatile("":"+r"(x)); return
x;}(); //✓
(void)[]{ register Long x asm("rdx"); asm volatile("":"+r"(x)); return
x;}(); //✗ on g++ :(
#endif
}
This works in C mode and on clang and clang++, but g++ reports: `error:
address of explicit register variable ‘x’ requested` despite no explicit
address-taking.
https://godbolt.org/z/jxP5h3bMT
