[Bug c/66132] New: Undefined reference to inline function

[shea at shealevy dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66132

            Bug ID: 66132
           Summary: Undefined reference to inline function
           Product: gcc
           Version: 5.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: shea at shealevy dot com
  Target Milestone: ---

When compiling with the default optimization level, this code:

inline int foo() {
        return 1;
}

int main(int argc, char ** argv) {
        return foo();
}

results in an undefined reference error:

/tmp/ccRBjwvf.o: In function `main':
test.c:(.text+0x15): undefined reference to `foo'
collect2: error: ld returned 1 exit status

This goes away at -O2 (presumably because the function is actually inlined?)