devwren.c:12:7: warning: declaration does not declare anything
  QLock;
       ^
devwren.c:91:8: warning: passing argument 1 of ‘qlock’ from incompatible pointer type [-Wincompatible-pointer-types]
  qlock(w);
        ^
/home/seh/src/plan9port/include/libc.h:492:19: note: expected ‘QLock *’ {aka ‘struct QLock *’} but argument is of type ‘Wren *’ {aka ‘struct Wren *’}
 extern void qlock(QLock*);
                   ^~~~~~
devwren.c:96:10: warning: passing argument 1 of ‘qunlock’ from incompatible pointer type [-Wincompatible-pointer-types]
  qunlock(w);
          ^
/home/seh/src/plan9port/include/libc.h:493:21: note: expected ‘QLock *’ {aka ‘struct QLock *’} but argument is of type ‘Wren *’ {aka ‘struct Wren *’}
 extern void qunlock(QLock*);
                     ^~~~~~
devwren.c:157:8: warning: passing argument 1 of ‘qlock’ from incompatible pointer type [-Wincompatible-pointer-types]
  qlock(w);
        ^
/home/seh/src/plan9port/include/libc.h:492:19: note: expected ‘QLock *’ {aka ‘struct QLock *’} but argument is of type ‘Wren *’ {aka ‘struct Wren *’}
 extern void qlock(QLock*);
                   ^~~~~~
devwren.c:159:10: warning: passing argument 1 of ‘qunlock’ from incompatible pointer type [-Wincompatible-pointer-types]
  qunlock(w);
          ^
/home/seh/src/plan9port/include/libc.h:493:21: note: expected ‘QLock *’ {aka ‘struct QLock *’} but argument is of type ‘Wren *’ {aka ‘struct Wren *’}
 extern void qunlock(QLock*);
                     ^~~~~~
devwren.c:173:8: warning: passing argument 1 of ‘qlock’ from incompatible pointer type [-Wincompatible-pointer-types]
  qlock(w);
        ^
/home/seh/src/plan9port/include/libc.h:492:19: note: expected ‘QLock *’ {aka ‘struct QLock *’} but argument is of type ‘Wren *’ {aka ‘struct Wren *’}
 extern void qlock(QLock*);
                   ^~~~~~
devwren.c:175:10: warning: passing argument 1 of ‘qunlock’ from incompatible pointer type [-Wincompatible-pointer-types]
  qunlock(w);
          ^
/home/seh/src/plan9port/include/libc.h:493:21: note: expected ‘QLock *’ {aka ‘struct QLock *’} but argument is of type ‘Wren *’ {aka ‘struct Wren *’}
 extern void qunlock(QLock*);
                     ^~~~~~