The problem

Starting from g++-9 (and for g++-8.3.0) GCC will reject the asm volatile toplevel constructs:

CODE

asm volatile("some thing");

test.cc:1:5: error: expected ‘(’ before ‘volatile’
 asm volatile("some thing ");
    ^19:23, 15 April 2019 (UTC)~~
    (

The fix

The fix is simple: just drop volatile. There is no defined symbol ordering in object file anyway:

CODE

asm ("some thing ");