[PATCH v2 0/8] configure: Change to -std=gnu11

[PATCH v2 0/8] configure: Change to -std=gnu11

[Richard Henderson]

Now that we assume gcc 7.5 as a minimum, we have the option of
changing to a newer C standard.  The two major new features that
I think apply are _Generic and _Static_assert.

While Paolo created a remarkably functional replacement for _Generic
using builtins, the error messages that you get out of the keyword
are *vastly* more intelligable, and the syntax is easier to read.

While I'd like to prefer _Static_assert over QEMU_BUILD_BUG_ON
going forward, and would like to convert existing uses, that is
a much bigger job.  Especially since the test condition is inverted.
In the meantime, can drop the configure detection.

Changes for v2:
  * Remove QEMU_LOCK_FUNC and QEMU_UNLOCK_FUNC as unused.


r~


Richard Henderson (8):
  configure: Use -std=gnu11
  softfloat: Use _Generic instead of QEMU_GENERIC
  util: Use real functions for thread-posix QemuRecMutex
  util: Pass file+line to qemu_rec_mutex_unlock_impl
  util: Use unique type for QemuRecMutex in thread-posix.h
  include/qemu/lockable: Use _Generic instead of QEMU_GENERIC
  qemu/compiler: Remove QEMU_GENERIC
  configure: Remove probe for _Static_assert

 configure                   | 22 +--------
 meson.build                 |  2 +-
 include/qemu/compiler.h     | 51 ---------------------
 include/qemu/lockable.h     | 90 +++++++++++++++++--------------------
 include/qemu/thread-posix.h | 14 +++---
 include/qemu/thread-win32.h |  6 ---
 include/qemu/thread.h       | 15 ++++++-
 fpu/softfloat.c             | 16 ++++---
 util/qemu-thread-posix.c    | 24 +++++++++-
 util/qemu-thread-win32.c    |  2 +-
 10 files changed, 98 insertions(+), 144 deletions(-)

-- 
2.25.1

[PATCH v2 1/8] configure: Use -std=gnu11

[Richard Henderson]

Now that the minimum gcc version is 7.5, we can use C11.
This will allow lots of cleanups to the code, currently
hidden behind macros in include/qemu/compiler.h.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 configure   | 4 ++--
 meson.build | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/configure b/configure
index 8dcb9965b2..0489864667 100755
--- a/configure
+++ b/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=
 
 
diff --git a/meson.build b/meson.build
index a2311eda6e..d8a92666fb 100644
--- a/meson.build
+++ b/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())
 
-- 
2.25.1

Re: [PATCH v2 1/8] configure: Use -std=gnu11

[Thomas Huth]

On 15/06/2021 01.31, Richard Henderson wrote:
> Now that the minimum gcc version is 7.5, we can use C11.
> This will allow lots of cleanups to the code, currently
> hidden behind macros in include/qemu/compiler.h.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   configure   | 4 ++--
>   meson.build | 2 +-
>   2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/configure b/configure
> index 8dcb9965b2..0489864667 100755
> --- a/configure
> +++ b/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=
>   
>   
> diff --git a/meson.build b/meson.build
> index a2311eda6e..d8a92666fb 100644
> --- a/meson.build
> +++ b/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())

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [PATCH v2 1/8] configure: Use -std=gnu11

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> Now that the minimum gcc version is 7.5, we can use C11.
> This will allow lots of cleanups to the code, currently
> hidden behind macros in include/qemu/compiler.h.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

Re: [PATCH v2 1/8] configure: Use -std=gnu11

[Philippe Mathieu-Daudé]

On 6/15/21 1:31 AM, Richard Henderson wrote:
> Now that the minimum gcc version is 7.5, we can use C11.
> This will allow lots of cleanups to the code, currently
> hidden behind macros in include/qemu/compiler.h.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  configure   | 4 ++--
>  meson.build | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

[PATCH v2 2/8] softfloat: Use _Generic instead of QEMU_GENERIC

[Richard Henderson]

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 fpu/softfloat.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index 4d0160fe9c..6e769f990c 100644
--- a/fpu/softfloat.c
+++ b/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), \
-                 (FloatParts128 *, parts128_##NAME), parts64_##NAME)
+    _Generic((P), FloatParts64 *: 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), \
-                 (FloatParts128 *, frac128_##NAME), frac64_##NAME)
+    _Generic((P), FloatParts64 *: frac64_##NAME, \
+                  FloatParts128 *: frac128_##NAME, \
+                  FloatParts256 *: frac256_##NAME)
 
 static bool frac64_add(FloatParts64 *r, FloatParts64 *a, FloatParts64 *b)
 {
-- 
2.25.1

Re: [PATCH v2 2/8] softfloat: Use _Generic instead of QEMU_GENERIC

[Thomas Huth]

On 15/06/2021 01.31, Richard Henderson wrote:
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   fpu/softfloat.c | 16 ++++++++++------
>   1 file changed, 10 insertions(+), 6 deletions(-)
> 
> diff --git a/fpu/softfloat.c b/fpu/softfloat.c
> index 4d0160fe9c..6e769f990c 100644
> --- a/fpu/softfloat.c
> +++ b/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), \
> -                 (FloatParts128 *, parts128_##NAME), parts64_##NAME)
> +    _Generic((P), FloatParts64 *: 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), \
> -                 (FloatParts128 *, frac128_##NAME), frac64_##NAME)
> +    _Generic((P), FloatParts64 *: frac64_##NAME, \
> +                  FloatParts128 *: frac128_##NAME, \
> +                  FloatParts256 *: frac256_##NAME)
>   
>   static bool frac64_add(FloatParts64 *r, FloatParts64 *a, FloatParts64 *b)
>   {
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [PATCH v2 2/8] softfloat: Use _Generic instead of QEMU_GENERIC

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

[PATCH v2 3/8] util: Use real functions for thread-posix QemuRecMutex

[Richard Henderson]

Move the declarations from thread-win32.h into thread.h
and remove the macro redirection from thread-posix.h.
This will be required by following cleanups.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/qemu/thread-posix.h |  4 ----
 include/qemu/thread-win32.h |  6 ------
 include/qemu/thread.h       |  9 ++++++---
 util/qemu-thread-posix.c    | 20 ++++++++++++++++++++
 4 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h
index c903525062..cf8bc90468 100644
--- a/include/qemu/thread-posix.h
+++ b/include/qemu/thread-posix.h
@@ -5,10 +5,6 @@
 #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;
diff --git a/include/qemu/thread-win32.h b/include/qemu/thread-win32.h
index d0a1a9597e..d95af4498f 100644
--- a/include/qemu/thread-win32.h
+++ b/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;
diff --git a/include/qemu/thread.h b/include/qemu/thread.h
index 5435763184..2c0d85f3bc 100644
--- a/include/qemu/thread.h
+++ b/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(QemuRecMutex *mutex);
+
 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);
@@ -129,9 +135,6 @@ 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.  */
-void qemu_rec_mutex_init(QemuRecMutex *mutex);
-
 void qemu_cond_init(QemuCond *cond);
 void qemu_cond_destroy(QemuCond *cond);
 
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index dcff5e7c5d..8e2b6653f5 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -124,6 +124,26 @@ void qemu_rec_mutex_init(QemuRecMutex *mutex)
     mutex->initialized = true;
 }
 
+void qemu_rec_mutex_destroy(QemuRecMutex *mutex)
+{
+    qemu_mutex_destroy(mutex);
+}
+
+void qemu_rec_mutex_lock_impl(QemuRecMutex *mutex, const char *file, int line)
+{
+    qemu_mutex_lock_impl(mutex, file, line);
+}
+
+int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file, int line)
+{
+    return qemu_mutex_trylock_impl(mutex, file, line);
+}
+
+void qemu_rec_mutex_unlock(QemuRecMutex *mutex)
+{
+    qemu_mutex_unlock(mutex);
+}
+
 void qemu_cond_init(QemuCond *cond)
 {
     int err;
-- 
2.25.1

Re: [PATCH v2 3/8] util: Use real functions for thread-posix QemuRecMutex

[Thomas Huth]

On 15/06/2021 01.31, Richard Henderson wrote:
> Move the declarations from thread-win32.h into thread.h
> and remove the macro redirection from thread-posix.h.
> This will be required by following cleanups.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   include/qemu/thread-posix.h |  4 ----
>   include/qemu/thread-win32.h |  6 ------
>   include/qemu/thread.h       |  9 ++++++---
>   util/qemu-thread-posix.c    | 20 ++++++++++++++++++++
>   4 files changed, 26 insertions(+), 13 deletions(-)
> 
> diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h
> index c903525062..cf8bc90468 100644
> --- a/include/qemu/thread-posix.h
> +++ b/include/qemu/thread-posix.h
> @@ -5,10 +5,6 @@
>   #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;
> diff --git a/include/qemu/thread-win32.h b/include/qemu/thread-win32.h
> index d0a1a9597e..d95af4498f 100644
> --- a/include/qemu/thread-win32.h
> +++ b/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;
> diff --git a/include/qemu/thread.h b/include/qemu/thread.h
> index 5435763184..2c0d85f3bc 100644
> --- a/include/qemu/thread.h
> +++ b/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(QemuRecMutex *mutex);
> +
>   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);
> @@ -129,9 +135,6 @@ 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.  */
> -void qemu_rec_mutex_init(QemuRecMutex *mutex);
> -
>   void qemu_cond_init(QemuCond *cond);
>   void qemu_cond_destroy(QemuCond *cond);
>   
> diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
> index dcff5e7c5d..8e2b6653f5 100644
> --- a/util/qemu-thread-posix.c
> +++ b/util/qemu-thread-posix.c
> @@ -124,6 +124,26 @@ void qemu_rec_mutex_init(QemuRecMutex *mutex)
>       mutex->initialized = true;
>   }
>   
> +void qemu_rec_mutex_destroy(QemuRecMutex *mutex)
> +{
> +    qemu_mutex_destroy(mutex);
> +}
> +
> +void qemu_rec_mutex_lock_impl(QemuRecMutex *mutex, const char *file, int line)
> +{
> +    qemu_mutex_lock_impl(mutex, file, line);
> +}
> +
> +int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file, int line)
> +{
> +    return qemu_mutex_trylock_impl(mutex, file, line);
> +}
> +
> +void qemu_rec_mutex_unlock(QemuRecMutex *mutex)
> +{
> +    qemu_mutex_unlock(mutex);
> +}
> +
>   void qemu_cond_init(QemuCond *cond)
>   {
>       int err;
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [PATCH v2 3/8] util: Use real functions for thread-posix QemuRecMutex

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> Move the declarations from thread-win32.h into thread.h
> and remove the macro redirection from thread-posix.h.
> This will be required by following cleanups.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

[PATCH v2 4/8] util: Pass file+line to qemu_rec_mutex_unlock_impl

[Richard Henderson]

Create macros for file+line expansion in qemu_rec_mutex_unlock
like we have for qemu_mutex_unlock.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/qemu/thread.h    | 10 +++++++++-
 util/qemu-thread-posix.c |  4 ++--
 util/qemu-thread-win32.c |  2 +-
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/include/qemu/thread.h b/include/qemu/thread.h
index 2c0d85f3bc..460568d67d 100644
--- a/include/qemu/thread.h
+++ b/include/qemu/thread.h
@@ -32,7 +32,7 @@ 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(QemuRecMutex *mutex);
+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);
@@ -110,6 +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);
@@ -135,6 +138,11 @@ static inline int (qemu_rec_mutex_trylock)(QemuRecMutex *mutex)
     return qemu_rec_mutex_trylock(mutex);
 }
 
+static inline void (qemu_rec_mutex_unlock)(QemuRecMutex *mutex)
+{
+    qemu_rec_mutex_unlock(mutex);
+}
+
 void qemu_cond_init(QemuCond *cond);
 void qemu_cond_destroy(QemuCond *cond);
 
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index 8e2b6653f5..d990826ed8 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -139,9 +139,9 @@ int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file, int line)
     return qemu_mutex_trylock_impl(mutex, file, line);
 }
 
-void qemu_rec_mutex_unlock(QemuRecMutex *mutex)
+void qemu_rec_mutex_unlock_impl(QemuRecMutex *mutex, const char *file, int line)
 {
-    qemu_mutex_unlock(mutex);
+    qemu_mutex_unlock_impl(mutex, file, line);
 }
 
 void qemu_cond_init(QemuCond *cond)
diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c
index cb5aa2018c..52eb19f351 100644
--- a/util/qemu-thread-win32.c
+++ b/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);
-- 
2.25.1

Re: [PATCH v2 4/8] util: Pass file+line to qemu_rec_mutex_unlock_impl

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> Create macros for file+line expansion in qemu_rec_mutex_unlock
> like we have for qemu_mutex_unlock.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

Re: [PATCH v2 4/8] util: Pass file+line to qemu_rec_mutex_unlock_impl

[Philippe Mathieu-Daudé]

On 6/15/21 1:31 AM, Richard Henderson wrote:
> Create macros for file+line expansion in qemu_rec_mutex_unlock
> like we have for qemu_mutex_unlock.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  include/qemu/thread.h    | 10 +++++++++-
>  util/qemu-thread-posix.c |  4 ++--
>  util/qemu-thread-win32.c |  2 +-
>  3 files changed, 12 insertions(+), 4 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

[PATCH v2 5/8] util: Use unique type for QemuRecMutex in thread-posix.h

[Richard Henderson]

We will shortly convert lockable.h to _Generic, and we cannot
have two compatible types in the same expansion.  Wrap QemuMutex
in a struct, and unwrap in qemu-thread-posix.c.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/qemu/thread-posix.h | 10 ++++++++--
 util/qemu-thread-posix.c    | 12 ++++++------
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h
index cf8bc90468..b792e6ef37 100644
--- a/include/qemu/thread-posix.h
+++ b/include/qemu/thread-posix.h
@@ -4,8 +4,6 @@
 #include <pthread.h>
 #include <semaphore.h>
 
-typedef QemuMutex QemuRecMutex;
-
 struct QemuMutex {
     pthread_mutex_t lock;
 #ifdef CONFIG_DEBUG_MUTEX
@@ -15,6 +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;
diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index d990826ed8..fd9d714038 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -116,32 +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);
+    qemu_mutex_destroy(&mutex->m);
 }
 
 void qemu_rec_mutex_lock_impl(QemuRecMutex *mutex, const char *file, int line)
 {
-    qemu_mutex_lock_impl(mutex, file, 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, file, 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, file, line);
+    qemu_mutex_unlock_impl(&mutex->m, file, line);
 }
 
 void qemu_cond_init(QemuCond *cond)
-- 
2.25.1

Re: [PATCH v2 5/8] util: Use unique type for QemuRecMutex in thread-posix.h

[Thomas Huth]

On 15/06/2021 01.31, Richard Henderson wrote:
> We will shortly convert lockable.h to _Generic, and we cannot
> have two compatible types in the same expansion.  Wrap QemuMutex
> in a struct, and unwrap in qemu-thread-posix.c.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   include/qemu/thread-posix.h | 10 ++++++++--
>   util/qemu-thread-posix.c    | 12 ++++++------
>   2 files changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h
> index cf8bc90468..b792e6ef37 100644
> --- a/include/qemu/thread-posix.h
> +++ b/include/qemu/thread-posix.h
> @@ -4,8 +4,6 @@
>   #include <pthread.h>
>   #include <semaphore.h>
>   
> -typedef QemuMutex QemuRecMutex;
> -
>   struct QemuMutex {
>       pthread_mutex_t lock;
>   #ifdef CONFIG_DEBUG_MUTEX
> @@ -15,6 +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;
> diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
> index d990826ed8..fd9d714038 100644
> --- a/util/qemu-thread-posix.c
> +++ b/util/qemu-thread-posix.c
> @@ -116,32 +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);
> +    qemu_mutex_destroy(&mutex->m);
>   }
>   
>   void qemu_rec_mutex_lock_impl(QemuRecMutex *mutex, const char *file, int line)
>   {
> -    qemu_mutex_lock_impl(mutex, file, 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, file, 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, file, line);
> +    qemu_mutex_unlock_impl(&mutex->m, file, line);
>   }
>   
>   void qemu_cond_init(QemuCond *cond)
> 

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [PATCH v2 5/8] util: Use unique type for QemuRecMutex in thread-posix.h

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> We will shortly convert lockable.h to _Generic, and we cannot
> have two compatible types in the same expansion.  Wrap QemuMutex
> in a struct, and unwrap in qemu-thread-posix.c.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

[PATCH v2 6/8] include/qemu/lockable: Use _Generic instead of QEMU_GENERIC

[Richard Henderson]

This is both more and less complicated than our expansion
using __builtin_choose_expr and __builtin_types_compatible_p.

The expansion through QEMU_MAKE_LOCKABLE_ doesn't work because
we're not emumerating all of the types within the same _Generic,
which results in errors about unhandled cases.  We must also
handle void* explicitly, so that the NULL constant can be used.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/qemu/lockable.h | 90 +++++++++++++++++++----------------------
 1 file changed, 41 insertions(+), 49 deletions(-)

diff --git a/include/qemu/lockable.h b/include/qemu/lockable.h
index b620023141..86db7cb04c 100644
--- a/include/qemu/lockable.h
+++ b/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.  */
-#define QEMU_LOCK_FUNC(x) ((QemuLockUnlockFunc *)    \
-    QEMU_GENERIC(x,                                  \
-                 (QemuMutex *, qemu_mutex_lock),     \
-                 (QemuRecMutex *, qemu_rec_mutex_lock), \
-                 (CoMutex *, qemu_co_mutex_lock),    \
-                 (QemuSpin *, qemu_spin_lock),       \
-                 unknown_lock_type))
+static inline __attribute__((__always_inline__)) QemuLockable *
+qemu_null_lockable(void *x)
+{
+    if (x != NULL) {
+        qemu_build_not_reached();
+    }
+    return NULL;
+}
 
-#define QEMU_UNLOCK_FUNC(x) ((QemuLockUnlockFunc *)  \
-    QEMU_GENERIC(x,                                  \
-                 (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, 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) {     \
-        .object = (x),                               \
-        .lock = QEMU_LOCK_FUNC(x),                   \
-        .unlock = QEMU_UNLOCK_FUNC(x),               \
+#define QML_OBJ_(x, name) (&(QemuLockable) {                            \
+        .object = (x),                                                  \
+        .lock = (QemuLockUnlockFunc *) qemu_ ## name ## _lock,          \
+        .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.
- */
-#define QEMU_MAKE_LOCKABLE(x)                        \
-    QEMU_GENERIC(x,                                  \
-                 (QemuLockable *, (x)),              \
-                 qemu_make_lockable((x), QEMU_MAKE_LOCKABLE_(x)))
-
-/* QEMU_MAKE_LOCKABLE_NONNULL - Make a polymorphic QemuLockable
  *
- * @x: a lock object (currently one of QemuMutex, QemuRecMutex, CoMutex, QemuSpin).
+ * Note the special case for void *, so that we may pass "NULL".
+ */
+#define QEMU_MAKE_LOCKABLE(x)                                           \
+    _Generic((x), QemuLockable *: (x),                                  \
+             void *: qemu_null_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
+ *
+ * @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,                                  \
-                 (QemuLockable *, (x)),              \
-                 QEMU_MAKE_LOCKABLE_(x))
+#define QEMU_MAKE_LOCKABLE_NONNULL(x)                           \
+    _Generic((x), QemuLockable *: (x),                          \
+                  QemuMutex *: QML_OBJ_(x, mutex),              \
+                  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)
 {
-- 
2.25.1

Re: [PATCH v2 6/8] include/qemu/lockable: Use _Generic instead of QEMU_GENERIC

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> This is both more and less complicated than our expansion
> using __builtin_choose_expr and __builtin_types_compatible_p.
>
> The expansion through QEMU_MAKE_LOCKABLE_ doesn't work because
> we're not emumerating all of the types within the same _Generic,
> which results in errors about unhandled cases.  We must also
> handle void* explicitly, so that the NULL constant can be used.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

and I checked that sync-profile was still working so:

Tested-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

[PATCH v2 7/8] qemu/compiler: Remove QEMU_GENERIC

[Richard Henderson]

All previous users now use C11 _Generic.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 include/qemu/compiler.h | 40 ----------------------------------------
 1 file changed, 40 deletions(-)

diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 091c45248b..5766d61589 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -173,46 +173,6 @@
 #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()
  *
-- 
2.25.1

Re: [PATCH v2 7/8] qemu/compiler: Remove QEMU_GENERIC

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> All previous users now use C11 _Generic.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

[PATCH v2 8/8] configure: Remove probe for _Static_assert

[Richard Henderson]

_Static_assert is part of C11, which is now required.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 configure               | 18 ------------------
 include/qemu/compiler.h | 11 -----------
 2 files changed, 29 deletions(-)

diff --git a/configure b/configure
index 0489864667..debd50c085 100755
--- a/configure
+++ b/configure
@@ -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
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index 5766d61589..3baa5e3790 100644
--- a/include/qemu/compiler.h
+++ 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)
 
-- 
2.25.1

Re: [PATCH v2 8/8] configure: Remove probe for _Static_assert

[Thomas Huth]

On 15/06/2021 01.31, Richard Henderson wrote:
> _Static_assert is part of C11, which is now required.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   configure               | 18 ------------------
>   include/qemu/compiler.h | 11 -----------
>   2 files changed, 29 deletions(-)
> 
> diff --git a/configure b/configure
> index 0489864667..debd50c085 100755
> --- a/configure
> +++ b/configure
> @@ -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
> diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
> index 5766d61589..3baa5e3790 100644
> --- a/include/qemu/compiler.h
> +++ 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)

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [PATCH v2 8/8] configure: Remove probe for _Static_assert

[Alex Bennée]

Richard Henderson <richard.henderson@linaro.org> writes:

> _Static_assert is part of C11, which is now required.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

Re: [PATCH v2 0/8] configure: Change to -std=gnu11

[no-reply]

Patchew URL: https://patchew.org/QEMU/20210614233143.1221879-1-richard.henderson@linaro.org/



Hi,

This series seems to have some coding style problems. See output below for
more information:

Type: series
Message-id: 20210614233143.1221879-1-richard.henderson@linaro.org
Subject: [PATCH v2 0/8] configure: Change to -std=gnu11

=== TEST SCRIPT BEGIN ===
#!/bin/bash
git rev-parse base > /dev/null || exit 0
git config --local diff.renamelimit 0
git config --local diff.renames True
git config --local diff.algorithm histogram
./scripts/checkpatch.pl --mailback base..
=== TEST SCRIPT END ===

Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384
From https://github.com/patchew-project/qemu
 * [new tag]         patchew/20210614233143.1221879-1-richard.henderson@linaro.org -> patchew/20210614233143.1221879-1-richard.henderson@linaro.org
Switched to a new branch 'test'
1a974ee configure: Remove probe for _Static_assert
8a8c552 qemu/compiler: Remove QEMU_GENERIC
d52ca80 include/qemu/lockable: Use _Generic instead of QEMU_GENERIC
d751cc8 util: Use unique type for QemuRecMutex in thread-posix.h
aafe079 util: Pass file+line to qemu_rec_mutex_unlock_impl
069b4e3 util: Use real functions for thread-posix QemuRecMutex
df9952e softfloat: Use _Generic instead of QEMU_GENERIC
067736a configure: Use -std=gnu11

=== OUTPUT BEGIN ===
1/8 Checking commit 067736abd82a (configure: Use -std=gnu11)
2/8 Checking commit df9952ebdce3 (softfloat: Use _Generic instead of QEMU_GENERIC)
ERROR: spaces required around that '*' (ctx:WxO)
#22: FILE: fpu/softfloat.c:689:
+    _Generic((P), FloatParts64 *: parts64_##NAME, \
                                ^

ERROR: spaces required around that ':' (ctx:OxW)
#22: FILE: fpu/softfloat.c:689:
+    _Generic((P), FloatParts64 *: parts64_##NAME, \
                                 ^

ERROR: spaces required around that '*' (ctx:WxO)
#23: FILE: fpu/softfloat.c:690:
+                  FloatParts128 *: parts128_##NAME)
                                 ^

ERROR: spaces required around that ':' (ctx:OxW)
#23: FILE: fpu/softfloat.c:690:
+                  FloatParts128 *: parts128_##NAME)
                                  ^

ERROR: spaces required around that '*' (ctx:WxO)
#28: FILE: fpu/softfloat.c:693:
+    _Generic((P), FloatParts64 *: parts64_##NAME, \
                                ^

ERROR: spaces required around that ':' (ctx:OxW)
#28: FILE: fpu/softfloat.c:693:
+    _Generic((P), FloatParts64 *: parts64_##NAME, \
                                 ^

ERROR: spaces required around that '*' (ctx:WxO)
#29: FILE: fpu/softfloat.c:694:
+                  FloatParts128 *: parts128_##NAME, \
                                 ^

ERROR: spaces required around that ':' (ctx:OxW)
#29: FILE: fpu/softfloat.c:694:
+                  FloatParts128 *: parts128_##NAME, \
                                  ^

ERROR: spaces required around that '*' (ctx:WxO)
#30: FILE: fpu/softfloat.c:695:
+                  FloatParts256 *: parts256_##NAME)
                                 ^

ERROR: spaces required around that ':' (ctx:OxW)
#30: FILE: fpu/softfloat.c:695:
+                  FloatParts256 *: parts256_##NAME)
                                  ^

ERROR: spaces required around that '*' (ctx:WxO)
#39: FILE: fpu/softfloat.c:897:
+    _Generic((P), FloatParts64 *: frac64_##NAME, \
                                ^

ERROR: spaces required around that ':' (ctx:OxW)
#39: FILE: fpu/softfloat.c:897:
+    _Generic((P), FloatParts64 *: frac64_##NAME, \
                                 ^

ERROR: spaces required around that '*' (ctx:WxO)
#40: FILE: fpu/softfloat.c:898:
+                  FloatParts128 *: frac128_##NAME)
                                 ^

ERROR: spaces required around that ':' (ctx:OxW)
#40: FILE: fpu/softfloat.c:898:
+                  FloatParts128 *: frac128_##NAME)
                                  ^

ERROR: spaces required around that '*' (ctx:WxO)
#45: FILE: fpu/softfloat.c:901:
+    _Generic((P), FloatParts64 *: frac64_##NAME, \
                                ^

ERROR: spaces required around that ':' (ctx:OxW)
#45: FILE: fpu/softfloat.c:901:
+    _Generic((P), FloatParts64 *: frac64_##NAME, \
                                 ^

ERROR: spaces required around that '*' (ctx:WxO)
#46: FILE: fpu/softfloat.c:902:
+                  FloatParts128 *: frac128_##NAME, \
                                 ^

ERROR: spaces required around that ':' (ctx:OxW)
#46: FILE: fpu/softfloat.c:902:
+                  FloatParts128 *: frac128_##NAME, \
                                  ^

ERROR: spaces required around that '*' (ctx:WxO)
#47: FILE: fpu/softfloat.c:903:
+                  FloatParts256 *: frac256_##NAME)
                                 ^

ERROR: spaces required around that ':' (ctx:OxW)
#47: FILE: fpu/softfloat.c:903:
+                  FloatParts256 *: frac256_##NAME)
                                  ^

total: 20 errors, 0 warnings, 32 lines checked

Patch 2/8 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

3/8 Checking commit 069b4e39c6b3 (util: Use real functions for thread-posix QemuRecMutex)
WARNING: line over 80 characters
#63: FILE: include/qemu/thread.h:34:
+int qemu_rec_mutex_trylock_impl(QemuRecMutex *mutex, const char *file, int line);

total: 0 errors, 1 warnings, 69 lines checked

Patch 3/8 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
4/8 Checking commit aafe07917c3a (util: Pass file+line to qemu_rec_mutex_unlock_impl)
WARNING: line over 80 characters
#27: FILE: include/qemu/thread.h:35:
+void qemu_rec_mutex_unlock_impl(QemuRecMutex *mutex, const char *file, int line);

total: 0 errors, 1 warnings, 47 lines checked

Patch 4/8 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.
5/8 Checking commit d751cc87cfad (util: Use unique type for QemuRecMutex in thread-posix.h)
6/8 Checking commit d52ca8068133 (include/qemu/lockable: Use _Generic instead of QEMU_GENERIC)
ERROR: spaces required around that '*' (ctx:WxO)
#117: FILE: include/qemu/lockable.h:70:
+    _Generic((x), QemuLockable *: (x),                                  \
                                ^

ERROR: spaces required around that ':' (ctx:OxW)
#117: FILE: include/qemu/lockable.h:70:
+    _Generic((x), QemuLockable *: (x),                                  \
                                 ^

ERROR: spaces required around that '*' (ctx:WxO)
#118: FILE: include/qemu/lockable.h:71:
+             void *: qemu_null_lockable(x),                             \
                   ^

ERROR: spaces required around that ':' (ctx:OxW)
#118: FILE: include/qemu/lockable.h:71:
+             void *: qemu_null_lockable(x),                             \
                    ^

ERROR: spaces required around that '*' (ctx:WxO)
#119: FILE: include/qemu/lockable.h:72:
+             QemuMutex *: qemu_make_lockable(x, QML_OBJ_(x, mutex)),    \
                        ^

ERROR: spaces required around that ':' (ctx:OxW)
#119: FILE: include/qemu/lockable.h:72:
+             QemuMutex *: qemu_make_lockable(x, QML_OBJ_(x, mutex)),    \
                         ^

ERROR: spaces required around that '*' (ctx:WxO)
#120: FILE: include/qemu/lockable.h:73:
+             QemuRecMutex *: qemu_make_lockable(x, QML_OBJ_(x, rec_mutex)), \
                           ^

ERROR: spaces required around that ':' (ctx:OxW)
#120: FILE: include/qemu/lockable.h:73:
+             QemuRecMutex *: qemu_make_lockable(x, QML_OBJ_(x, rec_mutex)), \
                            ^

ERROR: spaces required around that '*' (ctx:WxO)
#121: FILE: include/qemu/lockable.h:74:
+             CoMutex *: qemu_make_lockable(x, QML_OBJ_(x, co_mutex)),   \
                      ^

ERROR: spaces required around that ':' (ctx:OxW)
#121: FILE: include/qemu/lockable.h:74:
+             CoMutex *: qemu_make_lockable(x, QML_OBJ_(x, co_mutex)),   \
                       ^

ERROR: spaces required around that '*' (ctx:WxO)
#122: FILE: include/qemu/lockable.h:75:
+             QemuSpin *: qemu_make_lockable(x, QML_OBJ_(x, spin)))
                       ^

ERROR: spaces required around that ':' (ctx:OxW)
#122: FILE: include/qemu/lockable.h:75:
+             QemuSpin *: qemu_make_lockable(x, QML_OBJ_(x, spin)))
                        ^

ERROR: spaces required around that '*' (ctx:WxO)
#138: FILE: include/qemu/lockable.h:87:
+    _Generic((x), QemuLockable *: (x),                          \
                                ^

ERROR: spaces required around that ':' (ctx:OxW)
#138: FILE: include/qemu/lockable.h:87:
+    _Generic((x), QemuLockable *: (x),                          \
                                 ^

ERROR: spaces required around that '*' (ctx:WxO)
#139: FILE: include/qemu/lockable.h:88:
+                  QemuMutex *: QML_OBJ_(x, mutex),              \
                             ^

ERROR: spaces required around that ':' (ctx:OxW)
#139: FILE: include/qemu/lockable.h:88:
+                  QemuMutex *: QML_OBJ_(x, mutex),              \
                              ^

ERROR: spaces required around that '*' (ctx:WxO)
#140: FILE: include/qemu/lockable.h:89:
+                  QemuRecMutex *: QML_OBJ_(x, rec_mutex),       \
                                ^

ERROR: spaces required around that ':' (ctx:OxW)
#140: FILE: include/qemu/lockable.h:89:
+                  QemuRecMutex *: QML_OBJ_(x, rec_mutex),       \
                                 ^

ERROR: spaces required around that '*' (ctx:WxO)
#141: FILE: include/qemu/lockable.h:90:
+                  CoMutex *: QML_OBJ_(x, co_mutex),             \
                           ^

ERROR: spaces required around that ':' (ctx:OxW)
#141: FILE: include/qemu/lockable.h:90:
+                  CoMutex *: QML_OBJ_(x, co_mutex),             \
                            ^

ERROR: spaces required around that '*' (ctx:WxO)
#142: FILE: include/qemu/lockable.h:91:
+                  QemuSpin *: QML_OBJ_(x, spin))
                            ^

ERROR: spaces required around that ':' (ctx:OxW)
#142: FILE: include/qemu/lockable.h:91:
+                  QemuSpin *: QML_OBJ_(x, spin))
                             ^

total: 22 errors, 0 warnings, 120 lines checked

Patch 6/8 has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

7/8 Checking commit 8a8c55217a6f (qemu/compiler: Remove QEMU_GENERIC)
8/8 Checking commit 1a974eea8590 (configure: Remove probe for _Static_assert)
=== OUTPUT END ===

Test command exited with code: 1


The full log is available at
http://patchew.org/logs/20210614233143.1221879-1-richard.henderson@linaro.org/testing.checkpatch/?type=message.
---
Email generated automatically by Patchew [https://patchew.org/].
Please send your feedback to patchew-devel@redhat.com

Re: [PATCH v2 0/8] configure: Change to -std=gnu11

[Paolo Bonzini]

On 15/06/21 01:31, Richard Henderson wrote:
> Now that we assume gcc 7.5 as a minimum, we have the option of
> changing to a newer C standard.  The two major new features that
> I think apply are _Generic and _Static_assert.
> 
> While Paolo created a remarkably functional replacement for _Generic
> using builtins, the error messages that you get out of the keyword
> are *vastly* more intelligable, and the syntax is easier to read.
> 
> While I'd like to prefer _Static_assert over QEMU_BUILD_BUG_ON
> going forward, and would like to convert existing uses, that is
> a much bigger job.  Especially since the test condition is inverted.
> In the meantime, can drop the configure detection.
> 
> Changes for v2:
>    * Remove QEMU_LOCK_FUNC and QEMU_UNLOCK_FUNC as unused.
> 
> 
> r~
> 
> 
> Richard Henderson (8):
>    configure: Use -std=gnu11
>    softfloat: Use _Generic instead of QEMU_GENERIC
>    util: Use real functions for thread-posix QemuRecMutex
>    util: Pass file+line to qemu_rec_mutex_unlock_impl
>    util: Use unique type for QemuRecMutex in thread-posix.h
>    include/qemu/lockable: Use _Generic instead of QEMU_GENERIC
>    qemu/compiler: Remove QEMU_GENERIC
>    configure: Remove probe for _Static_assert
> 
>   configure                   | 22 +--------
>   meson.build                 |  2 +-
>   include/qemu/compiler.h     | 51 ---------------------
>   include/qemu/lockable.h     | 90 +++++++++++++++++--------------------
>   include/qemu/thread-posix.h | 14 +++---
>   include/qemu/thread-win32.h |  6 ---
>   include/qemu/thread.h       | 15 ++++++-
>   fpu/softfloat.c             | 16 ++++---
>   util/qemu-thread-posix.c    | 24 +++++++++-
>   util/qemu-thread-win32.c    |  2 +-
>   10 files changed, 98 insertions(+), 144 deletions(-)
> 

Queued, thanks.

Paolo