[PATCH 1/2] Remove GCC version checks (all < 4.8)

[marcandre . lureau]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

Since commit efc6c07 ("configure: Add a test for the minimum compiler
version"), QEMU explicitely depends on GCC >= 4.8.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 include/qemu/atomic.h         | 17 -----------------
 include/qemu/compiler.h       | 22 ++++++----------------
 include/qemu/qemu-plugin.h    |  9 ++-------
 tools/virtiofsd/fuse_common.h |  4 +---
 accel/tcg/cpu-exec.c          |  2 +-
 tests/tcg/arm/fcvt.c          |  8 +++-----
 6 files changed, 13 insertions(+), 49 deletions(-)

diff --git a/include/qemu/atomic.h b/include/qemu/atomic.h
index c1d211a351..8f4b3a80fb 100644
--- a/include/qemu/atomic.h
+++ b/include/qemu/atomic.h
@@ -241,23 +241,6 @@
 
 #else /* __ATOMIC_RELAXED */
 
-/*
- * We use GCC builtin if it's available, as that can use mfence on
- * 32-bit as well, e.g. if built with -march=pentium-m. However, on
- * i386 the spec is buggy, and the implementation followed it until
- * 4.3 (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36793).
- */
-#if defined(__i386__) || defined(__x86_64__)
-#if !QEMU_GNUC_PREREQ(4, 4)
-#if defined __x86_64__
-#define smp_mb()    ({ asm volatile("mfence" ::: "memory"); (void)0; })
-#else
-#define smp_mb()    ({ asm volatile("lock; addl $0,0(%%esp) " ::: "memory"); 
(void)0; })
-#endif
-#endif
-#endif
-
-
 #ifdef __alpha__
 #define smp_read_barrier_depends()   asm volatile("mb":::"memory")
 #endif
diff --git a/include/qemu/compiler.h b/include/qemu/compiler.h
index c76281f354..e391de15ef 100644
--- a/include/qemu/compiler.h
+++ b/include/qemu/compiler.h
@@ -44,10 +44,6 @@
 #endif
 
 #ifndef likely
-#if __GNUC__ < 3
-#define __builtin_expect(x, n) (x)
-#endif
-
 #define likely(x)   __builtin_expect(!!(x), 1)
 #define unlikely(x)   __builtin_expect(!!(x), 0)
 #endif
@@ -104,20 +100,14 @@
                                    sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)))
 
 #if defined __GNUC__
-# if !QEMU_GNUC_PREREQ(4, 4)
-   /* gcc versions before 4.4.x don't support gnu_printf, so use printf. */
-#  define GCC_FMT_ATTR(n, m) __attribute__((format(printf, n, m)))
-# else
-   /* Use gnu_printf when supported (qemu uses standard format strings). */
-#  define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
-#  if defined(_WIN32)
-    /* Map __printf__ to __gnu_printf__ because we want standard format strings
-     * even when MinGW or GLib include files use __printf__. */
-#   define __printf__ __gnu_printf__
-#  endif
+# define GCC_FMT_ATTR(n, m) __attribute__((format(gnu_printf, n, m)))
+# if defined(_WIN32)
+   /* Map __printf__ to __gnu_printf__ because we want standard format strings
+    * even when MinGW or GLib include files use __printf__. */
+#  define __printf__ __gnu_printf__
 # endif
 #else
-#define GCC_FMT_ATTR(n, m)
+# define GCC_FMT_ATTR(n, m)
 #endif
 
 #ifndef __has_warning
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h
index bab8b0d4b3..5775e82c4e 100644
--- a/include/qemu/qemu-plugin.h
+++ b/include/qemu/qemu-plugin.h
@@ -28,13 +28,8 @@
   #endif
   #define QEMU_PLUGIN_LOCAL
 #else
-  #if __GNUC__ >= 4
-    #define QEMU_PLUGIN_EXPORT __attribute__((visibility("default")))
-    #define QEMU_PLUGIN_LOCAL  __attribute__((visibility("hidden")))
-  #else
-    #define QEMU_PLUGIN_EXPORT
-    #define QEMU_PLUGIN_LOCAL
-  #endif
+  #define QEMU_PLUGIN_EXPORT __attribute__((visibility("default")))
+  #define QEMU_PLUGIN_LOCAL  __attribute__((visibility("hidden")))
 #endif
 
 typedef uint64_t qemu_plugin_id_t;
diff --git a/tools/virtiofsd/fuse_common.h b/tools/virtiofsd/fuse_common.h
index 5aee5193eb..2f073578fe 100644
--- a/tools/virtiofsd/fuse_common.h
+++ b/tools/virtiofsd/fuse_common.h
@@ -810,9 +810,7 @@ void fuse_remove_signal_handlers(struct fuse_session *se);
  * On 32bit systems please add -D_FILE_OFFSET_BITS=64 to your compile flags!
  */
 
-#if defined(__GNUC__) &&                                      \
-    (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 6) && \
-    !defined __cplusplus
+#if defined(__GNUC__) && !defined __cplusplus
 _Static_assert(sizeof(off_t) == 8, "fuse: off_t must be 64bit");
 #else
 struct _fuse_off_t_must_be_64bit_dummy_struct {
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 58aea605d8..37a88edb6d 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -724,7 +724,7 @@ int cpu_exec(CPUState *cpu)
 
     /* prepare setjmp context for exception handling */
     if (sigsetjmp(cpu->jmp_env, 0) != 0) {
-#if defined(__clang__) || !QEMU_GNUC_PREREQ(4, 6)
+#if defined(__clang__)
         /* Some compilers wrongly smash all local variables after
          * siglongjmp. There were bug reports for gcc 4.5.0 and clang.
          * Reload essential local variables here for those compilers.
diff --git a/tests/tcg/arm/fcvt.c b/tests/tcg/arm/fcvt.c
index 617626bc63..7ac47b564e 100644
--- a/tests/tcg/arm/fcvt.c
+++ b/tests/tcg/arm/fcvt.c
@@ -73,11 +73,9 @@ static void print_int64(int i, int64_t num)
 
 #ifndef SNANF
 /* Signaling NaN macros, if supported.  */
-# if __GNUC_PREREQ(3, 3)
-#  define SNANF (__builtin_nansf (""))
-#  define SNAN (__builtin_nans (""))
-#  define SNANL (__builtin_nansl (""))
-# endif
+# define SNANF (__builtin_nansf (""))
+# define SNAN (__builtin_nans (""))
+# define SNANL (__builtin_nansl (""))
 #endif
 
 float single_numbers[] = { -SNANF,
-- 
2.29.0