Change to -std=gnu11.

Replace QEMU_GENERIC with _Generic.
 Remove configure detect of _Static_assert.
 -----BEGIN PGP SIGNATURE-----
 
 iQFRBAABCgA7FiEEekgeeIaLTbaoWgXAZN846K9+IV8FAmDJVLAdHHJpY2hhcmQu
 aGVuZGVyc29uQGxpbmFyby5vcmcACgkQZN846K9+IV8ZqggAvFjHlhJM/eAcRSVu
 kw7dZ6ntbQABMvovsTa+pl3oNpy+z6i54L+HRGmuioEc8jZWjcpT7dswLFuTxy6s
 eQST0zPfu18Vu6kVzxep9BLxsGdO1FItu5xgPG5Dm9KWzod7ZZ1hp1QzEmnRkFpx
 fgnpTDDcstm7jokMzigipijdOrnwnDBHuKIP/pQzevA07IuaoBhRs/KxCHbM/BTz
 vgm/aYdVk7HB1595fwGR7pHALs31A5hNTUv8wcNlwKeli9tmg+u3b4Pwgc4EQAn+
 ZAC+hqU8d6XLLVBC+Xs8ko4aoygUbNxWGX9TJ5U+73gB8Hfh4MsPRoXeMFH+fah2
 UNsPTA==
 =yFhD
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/rth-gitlab/tags/pull-c11-20210615' into staging

Change to -std=gnu11.
Replace QEMU_GENERIC with _Generic.
Remove configure detect of _Static_assert.

# gpg: Signature made Wed 16 Jun 2021 02:32:32 BST
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* remotes/rth-gitlab/tags/pull-c11-20210615:
  configure: Remove probe for _Static_assert
  qemu/compiler: Remove QEMU_GENERIC
  include/qemu/lockable: Use _Generic instead of QEMU_GENERIC
  util: Use unique type for QemuRecMutex in thread-posix.h
  util: Pass file+line to qemu_rec_mutex_unlock_impl
  util: Use real functions for thread-posix QemuRecMutex
  softfloat: Use _Generic instead of QEMU_GENERIC
  configure: Use -std=gnu11

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

configure

@@ -159,7 +159,7 @@ update_cxxflags() {
     # options which some versions of GCC's C++ compiler complain about
     # because they only make sense for C programs.
     QEMU_CXXFLAGS="$QEMU_CXXFLAGS -D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS"
-    CONFIGURE_CXXFLAGS=$(echo "$CONFIGURE_CFLAGS" | sed s/-std=gnu99/-std=gnu++11/)
+    CONFIGURE_CXXFLAGS=$(echo "$CONFIGURE_CFLAGS" | sed s/-std=gnu11/-std=gnu++11/)
     for arg in $QEMU_CFLAGS; do
         case $arg in
             -Wstrict-prototypes|-Wmissing-prototypes|-Wnested-externs|\
@@ -538,7 +538,7 @@ QEMU_CFLAGS="-Wstrict-prototypes -Wredundant-decls $QEMU_CFLAGS"
 QEMU_CFLAGS="-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE $QEMU_CFLAGS"
 
 # Flags that are needed during configure but later taken care of by Meson
-CONFIGURE_CFLAGS="-std=gnu99 -Wall"
+CONFIGURE_CFLAGS="-std=gnu11 -Wall"
 CONFIGURE_LDFLAGS=
 
 
@@ -5090,20 +5090,6 @@ if compile_prog "" "" ; then
     have_sysmacros=yes
 fi
 
-##########################################
-# check for _Static_assert()
-
-have_static_assert=no
-cat > $TMPC << EOF
-_Static_assert(1, "success");
-int main(void) {
-    return 0;
-}
-EOF
-if compile_prog "" "" ; then
-    have_static_assert=yes
-fi
-
 ##########################################
 # check for utmpx.h, it is missing e.g. on OpenBSD
 
@@ -6035,10 +6021,6 @@ if test "$have_sysmacros" = "yes" ; then
   echo "CONFIG_SYSMACROS=y" >> $config_host_mak
 fi
 
-if test "$have_static_assert" = "yes" ; then
-  echo "CONFIG_STATIC_ASSERT=y" >> $config_host_mak
-fi
-
 if test "$have_utmpx" = "yes" ; then
   echo "HAVE_UTMPX=y" >> $config_host_mak
 fi

fpu/softfloat.c

@@ -686,11 +686,13 @@ static float128 float128_pack_raw(const FloatParts128 *p)
 #include "softfloat-specialize.c.inc"
 
 #define PARTS_GENERIC_64_128(NAME, P) \
-    QEMU_GENERIC(P, (FloatParts128 *, parts128_##NAME), parts64_##NAME)
+    _Generic((P), FloatParts64 *: parts64_##NAME, \
+                  FloatParts128 *: parts128_##NAME)
 
 #define PARTS_GENERIC_64_128_256(NAME, P) \
-    QEMU_GENERIC(P, (FloatParts256 *, parts256_##NAME), \
+    _Generic((P), FloatParts64 *: parts64_##NAME, \
-                 (FloatParts128 *, parts128_##NAME), parts64_##NAME)
+                  FloatParts128 *: parts128_##NAME, \
+                  FloatParts256 *: parts256_##NAME)
 
 #define parts_default_nan(P, S)    PARTS_GENERIC_64_128(default_nan, P)(P, S)
 #define parts_silence_nan(P, S)    PARTS_GENERIC_64_128(silence_nan, P)(P, S)
@@ -892,11 +894,13 @@ static void parts128_log2(FloatParts128 *a, float_status *s, const FloatFmt *f);
  */
 
 #define FRAC_GENERIC_64_128(NAME, P) \
-    QEMU_GENERIC(P, (FloatParts128 *, frac128_##NAME), frac64_##NAME)
+    _Generic((P), FloatParts64 *: frac64_##NAME, \
+                  FloatParts128 *: frac128_##NAME)
 
 #define FRAC_GENERIC_64_128_256(NAME, P) \
-    QEMU_GENERIC(P, (FloatParts256 *, frac256_##NAME), \
+    _Generic((P), FloatParts64 *: frac64_##NAME, \
-                 (FloatParts128 *, frac128_##NAME), frac64_##NAME)
+                  FloatParts128 *: frac128_##NAME, \
+                  FloatParts256 *: frac256_##NAME)
 
 static bool frac64_add(FloatParts64 *r, FloatParts64 *a, FloatParts64 *b)
 {

include/qemu/compiler.h

@@ -72,18 +72,7 @@
         int:(x) ? -1 : 1; \
     }
 
-/* QEMU_BUILD_BUG_MSG() emits the message given if _Static_assert is
- * supported; otherwise, it will be omitted from the compiler error
- * message (but as it remains present in the source code, it can still
- * be useful when debugging). */
-#if defined(CONFIG_STATIC_ASSERT)
 #define QEMU_BUILD_BUG_MSG(x, msg) _Static_assert(!(x), msg)
-#elif defined(__COUNTER__)
-#define QEMU_BUILD_BUG_MSG(x, msg) typedef QEMU_BUILD_BUG_ON_STRUCT(x) \
-    glue(qemu_build_bug_on__, __COUNTER__) __attribute__((unused))
-#else
-#define QEMU_BUILD_BUG_MSG(x, msg)
-#endif
 
 #define QEMU_BUILD_BUG_ON(x) QEMU_BUILD_BUG_MSG(x, "not expecting: " #x)
 
@@ -173,46 +162,6 @@
 #define QEMU_ALWAYS_INLINE
 #endif
 
-/* Implement C11 _Generic via GCC builtins.  Example:
- *
- *    QEMU_GENERIC(x, (float, sinf), (long double, sinl), sin) (x)
- *
- * The first argument is the discriminator.  The last is the default value.
- * The middle ones are tuples in "(type, expansion)" format.
- */
-
-/* First, find out the number of generic cases.  */
-#define QEMU_GENERIC(x, ...) \
-    QEMU_GENERIC_(typeof(x), __VA_ARGS__, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
-
-/* There will be extra arguments, but they are not used.  */
-#define QEMU_GENERIC_(x, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9, count, ...) \
-    QEMU_GENERIC##count(x, a0, a1, a2, a3, a4, a5, a6, a7, a8, a9)
-
-/* Two more helper macros, this time to extract items from a parenthesized
- * list.
- */
-#define QEMU_FIRST_(a, b) a
-#define QEMU_SECOND_(a, b) b
-
-/* ... and a final one for the common part of the "recursion".  */
-#define QEMU_GENERIC_IF(x, type_then, else_)                                   \
-    __builtin_choose_expr(__builtin_types_compatible_p(x,                      \
-                                                       QEMU_FIRST_ type_then), \
-                          QEMU_SECOND_ type_then, else_)
-
-/* CPP poor man's "recursion".  */
-#define QEMU_GENERIC1(x, a0, ...) (a0)
-#define QEMU_GENERIC2(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC1(x, __VA_ARGS__))
-#define QEMU_GENERIC3(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC2(x, __VA_ARGS__))
-#define QEMU_GENERIC4(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC3(x, __VA_ARGS__))
-#define QEMU_GENERIC5(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC4(x, __VA_ARGS__))
-#define QEMU_GENERIC6(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC5(x, __VA_ARGS__))
-#define QEMU_GENERIC7(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC6(x, __VA_ARGS__))
-#define QEMU_GENERIC8(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC7(x, __VA_ARGS__))
-#define QEMU_GENERIC9(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC8(x, __VA_ARGS__))
-#define QEMU_GENERIC10(x, a0, ...) QEMU_GENERIC_IF(x, a0, QEMU_GENERIC9(x, __VA_ARGS__))
-
 /**
  * qemu_build_not_reached()
  *

include/qemu/lockable.h

@@ -24,79 +24,71 @@ struct QemuLockable {
     QemuLockUnlockFunc *unlock;
 };
 
-/* 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 defined(__OPTIMIZE__) && !defined(__SANITIZE_ADDRESS__)
-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)
 {
-    /* We cannot test this in a macro, otherwise we get compiler
+    /*
+     * We cannot test this in a macro, otherwise we get compiler
      * warnings like "the address of 'm' will always evaluate as 'true'".
      */
     return x ? lockable : NULL;
 }
 
-/* Auxiliary macros to simplify QEMU_MAKE_LOCABLE.  */
+static inline __attribute__((__always_inline__)) QemuLockable *
-#define QEMU_LOCK_FUNC(x) ((QemuLockUnlockFunc *)    \
+qemu_null_lockable(void *x)
-    QEMU_GENERIC(x,                                  \
+{
-                 (QemuMutex *, qemu_mutex_lock),     \
+    if (x != NULL) {
-                 (QemuRecMutex *, qemu_rec_mutex_lock), \
+        qemu_build_not_reached();
-                 (CoMutex *, qemu_co_mutex_lock),    \
+    }
-                 (QemuSpin *, qemu_spin_lock),       \
+    return NULL;
-                 unknown_lock_type))
+}
 
-#define QEMU_UNLOCK_FUNC(x) ((QemuLockUnlockFunc *)  \
+/*
-    QEMU_GENERIC(x,                                  \
+ * In C, compound literals have the lifetime of an automatic variable.
-                 (QemuMutex *, qemu_mutex_unlock),   \
-                 (QemuRecMutex *, qemu_rec_mutex_unlock), \
-                 (CoMutex *, qemu_co_mutex_unlock),  \
-                 (QemuSpin *, qemu_spin_unlock),     \
-                 unknown_lock_type))
-
-/* In C, compound literals have the lifetime of an automatic variable.
  * In C++ it would be different, but then C++ wouldn't need QemuLockable
  * either...
  */
-#define QEMU_MAKE_LOCKABLE_(x) (&(QemuLockable) {     \
+#define QML_OBJ_(x, name) (&(QemuLockable) {                            \
         .object = (x),                                                  \
-        .lock = QEMU_LOCK_FUNC(x),                   \
+        .lock = (QemuLockUnlockFunc *) qemu_ ## name ## _lock,          \
-        .unlock = QEMU_UNLOCK_FUNC(x),               \
+        .unlock = (QemuLockUnlockFunc *) qemu_ ## name ## _unlock       \
     })
 
-/* QEMU_MAKE_LOCKABLE - Make a polymorphic QemuLockable
+/**
+ * QEMU_MAKE_LOCKABLE - Make a polymorphic QemuLockable
  *
- * @x: a lock object (currently one of QemuMutex, QemuRecMutex, CoMutex, QemuSpin).
+ * @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.
+ *
+ * Note the special case for void *, so that we may pass "NULL".
  */
 #define QEMU_MAKE_LOCKABLE(x)                                           \
-    QEMU_GENERIC(x,                                  \
+    _Generic((x), QemuLockable *: (x),                                  \
-                 (QemuLockable *, (x)),              \
+             void *: qemu_null_lockable(x),                             \
-                 qemu_make_lockable((x), QEMU_MAKE_LOCKABLE_(x)))
+             QemuMutex *: qemu_make_lockable(x, QML_OBJ_(x, mutex)),    \
+             QemuRecMutex *: qemu_make_lockable(x, QML_OBJ_(x, rec_mutex)), \
+             CoMutex *: qemu_make_lockable(x, QML_OBJ_(x, co_mutex)),   \
+             QemuSpin *: qemu_make_lockable(x, QML_OBJ_(x, spin)))
 
-/* QEMU_MAKE_LOCKABLE_NONNULL - Make a polymorphic QemuLockable
+/**
+ * QEMU_MAKE_LOCKABLE_NONNULL - Make a polymorphic QemuLockable
  *
- * @x: a lock object (currently one of QemuMutex, QemuRecMutex, CoMutex, QemuSpin).
+ * @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.
  */
 #define QEMU_MAKE_LOCKABLE_NONNULL(x)                           \
-    QEMU_GENERIC(x,                                  \
+    _Generic((x), QemuLockable *: (x),                          \
-                 (QemuLockable *, (x)),              \
+                  QemuMutex *: QML_OBJ_(x, mutex),              \
-                 QEMU_MAKE_LOCKABLE_(x))
+                  QemuRecMutex *: QML_OBJ_(x, rec_mutex),       \
+                  CoMutex *: QML_OBJ_(x, co_mutex),             \
+                  QemuSpin *: QML_OBJ_(x, spin))
 
 static inline void qemu_lockable_lock(QemuLockable *x)
 {

include/qemu/thread-posix.h

@@ -4,12 +4,6 @@
 #include <pthread.h>
 #include <semaphore.h>
 
-typedef QemuMutex QemuRecMutex;
-#define qemu_rec_mutex_destroy qemu_mutex_destroy
-#define qemu_rec_mutex_lock_impl    qemu_mutex_lock_impl
-#define qemu_rec_mutex_trylock_impl qemu_mutex_trylock_impl
-#define qemu_rec_mutex_unlock qemu_mutex_unlock
-
 struct QemuMutex {
     pthread_mutex_t lock;
 #ifdef CONFIG_DEBUG_MUTEX
@@ -19,6 +13,14 @@ struct QemuMutex {
     bool initialized;
 };
 
+/*
+ * QemuRecMutex cannot be a typedef of QemuMutex lest we have two
+ * compatible cases in _Generic.  See qemu/lockable.h.
+ */
+typedef struct QemuRecMutex {
+    QemuMutex m;
+} QemuRecMutex;
+
 struct QemuCond {
     pthread_cond_t cond;
     bool initialized;

include/qemu/thread-win32.h

@@ -18,12 +18,6 @@ struct QemuRecMutex {
     bool initialized;
 };
 
-void qemu_rec_mutex_destroy(QemuRecMutex *mutex);
-void qemu_rec_mutex_lock_impl(QemuRecMutex *mutex, const char *file, int line);
-int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file,
-                                int line);
-void qemu_rec_mutex_unlock(QemuRecMutex *mutex);
-
 struct QemuCond {
     CONDITION_VARIABLE var;
     bool initialized;

include/qemu/thread.h

@@ -28,6 +28,12 @@ int qemu_mutex_trylock_impl(QemuMutex *mutex, const char *file, const int line);
 void qemu_mutex_lock_impl(QemuMutex *mutex, const char *file, const int line);
 void qemu_mutex_unlock_impl(QemuMutex *mutex, const char *file, const int line);
 
+void qemu_rec_mutex_init(QemuRecMutex *mutex);
+void qemu_rec_mutex_destroy(QemuRecMutex *mutex);
+void qemu_rec_mutex_lock_impl(QemuRecMutex *mutex, const char *file, int line);
+int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file, int line);
+void qemu_rec_mutex_unlock_impl(QemuRecMutex *mutex, const char *file, int line);
+
 typedef void (*QemuMutexLockFunc)(QemuMutex *m, const char *f, int l);
 typedef int (*QemuMutexTrylockFunc)(QemuMutex *m, const char *f, int l);
 typedef void (*QemuRecMutexLockFunc)(QemuRecMutex *m, const char *f, int l);
@@ -104,6 +110,9 @@ extern QemuCondTimedWaitFunc qemu_cond_timedwait_func;
 #define qemu_mutex_unlock(mutex) \
         qemu_mutex_unlock_impl(mutex, __FILE__, __LINE__)
 
+#define qemu_rec_mutex_unlock(mutex) \
+        qemu_rec_mutex_unlock_impl(mutex, __FILE__, __LINE__)
+
 static inline void (qemu_mutex_lock)(QemuMutex *mutex)
 {
     qemu_mutex_lock(mutex);
@@ -129,8 +138,10 @@ static inline int (qemu_rec_mutex_trylock)(QemuRecMutex *mutex)
     return qemu_rec_mutex_trylock(mutex);
 }
 
-/* Prototypes for other functions are in thread-posix.h/thread-win32.h.  */
+static inline void (qemu_rec_mutex_unlock)(QemuRecMutex *mutex)
-void qemu_rec_mutex_init(QemuRecMutex *mutex);
+{
+    qemu_rec_mutex_unlock(mutex);
+}
 
 void qemu_cond_init(QemuCond *cond);
 void qemu_cond_destroy(QemuCond *cond);

meson.build

@@ -1,5 +1,5 @@
 project('qemu', ['c'], meson_version: '>=0.55.0',
-        default_options: ['warning_level=1', 'c_std=gnu99', 'cpp_std=gnu++11', 'b_colorout=auto'] +
+        default_options: ['warning_level=1', 'c_std=gnu11', 'cpp_std=gnu++11', 'b_colorout=auto'] +
                          (meson.version().version_compare('>=0.56.0') ? [ 'b_staticpic=false' ] : []),
         version: run_command('head', meson.source_root() / 'VERSION').stdout().strip())
 

util/qemu-thread-posix.c

@@ -116,12 +116,32 @@ void qemu_rec_mutex_init(QemuRecMutex *mutex)
 
     pthread_mutexattr_init(&attr);
     pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
-    err = pthread_mutex_init(&mutex->lock, &attr);
+    err = pthread_mutex_init(&mutex->m.lock, &attr);
     pthread_mutexattr_destroy(&attr);
     if (err) {
         error_exit(err, __func__);
     }
-    mutex->initialized = true;
+    mutex->m.initialized = true;
+}
+
+void qemu_rec_mutex_destroy(QemuRecMutex *mutex)
+{
+    qemu_mutex_destroy(&mutex->m);
+}
+
+void qemu_rec_mutex_lock_impl(QemuRecMutex *mutex, const char *file, int line)
+{
+    qemu_mutex_lock_impl(&mutex->m, file, line);
+}
+
+int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file, int line)
+{
+    return qemu_mutex_trylock_impl(&mutex->m, file, line);
+}
+
+void qemu_rec_mutex_unlock_impl(QemuRecMutex *mutex, const char *file, int line)
+{
+    qemu_mutex_unlock_impl(&mutex->m, file, line);
 }
 
 void qemu_cond_init(QemuCond *cond)

util/qemu-thread-win32.c

@@ -105,7 +105,7 @@ int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file, int line)
     return !TryEnterCriticalSection(&mutex->lock);
 }
 
-void qemu_rec_mutex_unlock(QemuRecMutex *mutex)
+void qemu_rec_mutex_unlock_impl(QemuRecMutex *mutex, const char *file, int line)
 {
     assert(mutex->initialized);
     LeaveCriticalSection(&mutex->lock);