| Message ID | 20200603224903.26268-3-joe.slater@windriver.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Use QLNULL for null lockable | expand |
On 6/3/20 5:49 PM, Joe Slater wrote: > If we use QLNULL for null lockables, we can always > use referencing unknown_lock_type as a link time > error indicator. > > Signed-off-by: Joe Slater <joe.slater@windriver.com> > --- > include/qemu/lockable.h | 19 ++++++------------- > 1 file changed, 6 insertions(+), 13 deletions(-) > > diff --git a/include/qemu/lockable.h b/include/qemu/lockable.h > index 7f7aebb..7fc5750 100644 > --- a/include/qemu/lockable.h > +++ b/include/qemu/lockable.h > @@ -24,21 +24,14 @@ struct QemuLockable { > QemuLockUnlockFunc *unlock; > }; > > -#define QLNULL ((QemuLockable *)0) > - > - > -/* This function gives an error if an invalid, non-NULL pointer type is passed > - * to QEMU_MAKE_LOCKABLE. For optimized builds, we can rely on dead-code elimination > - * from the compiler, and give the errors already at link time. > +/* > + * If unknown_lock_type() is referenced, it means we have tried to passed something > + * not recognized as lockable to the macros below. Use QLNULL to intentionally pass > + * a null lockable. > */ > -#if defined(__OPTIMIZE__) && !defined(__SANITIZE_ADDRESS__) > +#define QLNULL ((QemuLockable *)0) Looks like a bit of churn (especially if you take my comment on 1/2 to spell it NULL instead of 0). Should these be combined into a single patch? > void unknown_lock_type(void *); > -#else > -static inline void unknown_lock_type(void *unused) > -{ > - abort(); > -} > -#endif > + > > static inline __attribute__((__always_inline__)) QemuLockable * > qemu_make_lockable(void *x, QemuLockable *lockable) Reading further in the file: /* Auxiliary macros to simplify QEMU_MAKE_LOCABLE. */ We should fix that typo while improving things. /* QEMU_MAKE_LOCKABLE - Make a polymorphic QemuLockable * * @x: a lock object (currently one of QemuMutex, QemuRecMutex, CoMutex, QemuSpin). * * Returns a QemuLockable object that can be passed around * to a function that can operate with locks of any kind, or * NULL if @x is %NULL. Should this comment be tweaked to call out %QLNULL?
diff --git a/include/qemu/lockable.h b/include/qemu/lockable.h index 7f7aebb..7fc5750 100644 --- a/include/qemu/lockable.h +++ b/include/qemu/lockable.h @@ -24,21 +24,14 @@ struct QemuLockable { QemuLockUnlockFunc *unlock; }; -#define QLNULL ((QemuLockable *)0) - - -/* This function gives an error if an invalid, non-NULL pointer type is passed - * to QEMU_MAKE_LOCKABLE. For optimized builds, we can rely on dead-code elimination - * from the compiler, and give the errors already at link time. +/* + * If unknown_lock_type() is referenced, it means we have tried to passed something + * not recognized as lockable to the macros below. Use QLNULL to intentionally pass + * a null lockable. */ -#if defined(__OPTIMIZE__) && !defined(__SANITIZE_ADDRESS__) +#define QLNULL ((QemuLockable *)0) void unknown_lock_type(void *); -#else -static inline void unknown_lock_type(void *unused) -{ - abort(); -} -#endif + static inline __attribute__((__always_inline__)) QemuLockable * qemu_make_lockable(void *x, QemuLockable *lockable)
If we use QLNULL for null lockables, we can always use referencing unknown_lock_type as a link time error indicator. Signed-off-by: Joe Slater <joe.slater@windriver.com> --- include/qemu/lockable.h | 19 ++++++------------- 1 file changed, 6 insertions(+), 13 deletions(-)