[Bug ipa/97945] New: undefined reference err when a function defined inline

[dongjianqiang2 at huawei dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97945

            Bug ID: 97945
           Summary: undefined reference err when a function defined inline
           Product: gcc
           Version: 10.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dongjianqiang2 at huawei dot com
                CC: marxin at gcc dot gnu.org
  Target Milestone: ---

$ cat z1.c
#define likely(x) __builtin_expect((x), 1)
#define unlikely(x) __builtin_expect((x), 0)
int a=10;
inline void test() {
 __builtin_puts("hot");
 a++;
 __builtin_puts("hot");
}

void main() {
    __builtin_puts("hot");
    if (unlikely(a==2)) {
      test();
    }
    __builtin_puts("hot");
}

gcc test.c -O2

in function `main':
test.c:(.text.startup+0x38): undefined reference to `test'
collect2: error: ld returned 1 exit status

But succeed when compiling with -fgnu89-inline.