[Bug c++/90829] New: -fopenacc expects iteration declaration or initialization

[zhonghao at pku dot org.cn]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90829

            Bug ID: 90829
           Summary: -fopenacc  expects iteration declaration or
                    initialization
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zhonghao at pku dot org.cn
  Target Milestone: ---

My gcc is 10.0.0, and the code is:

void foo(float *f, double *r) {
#pragma acc kernels loop create(f) copy(r)
for(;;) {}
}

gcc accepts the code, but with -fopenacc, it rejects it:

<source>: In function 'void foo(float*, double*)':

<source>:3:1: error: expected iteration declaration or initialization

    3 | for(;;) {}

      | ^~~

Compiler returned: 1

Shall programmers explicitly provide iteration declaration or initialization,
with -fopenacc? If it is case, it is worth mentioning the requirement in its
manual.