[Spice-commits] common/log.h common/macros.h

[GitLab Mirror]

 common/log.h    |    8 ++++++--
 common/macros.h |    8 ++++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

New commits:
commit 4951c71553af7f4aba9a5e6df200757ff903aa10
Author: Christophe Fergeau <cfergeau at redhat.com>
Date:   Fri Mar 29 17:47:39 2019 +0100

    log: Let gcc know about the logging macros which abort
    
    This commit adds a SPICE_UNREACHABLE macro (courtesy of Frediano)
    so that gcc does not think that code control can go past
    spice_return_{val_,}if_fail(), spice_critical() and spice_error()
    
    This avoids this kind of warnings:
    
    fallthrough.c:
    
     #include "log.h"
    
    int main(int argc, char **argv)
    {
        switch(argc) {
            case 1:
                spice_critical("foo");
           default:
                return 0;
        }
    }
    
    $ gcc  -c    $(pkg-config --cflags --libs glib-2.0 spice-protocol)
           -I common   -Wimplicit-fallthrough=5 ./fallthrough.c
    In file included from ./fallthrough.c:1:
    ./fallthrough.c: In function 'main':
    common/log.h:73:5: warning: this statement may fall through [-Wimplicit-fallthrough=]
       73 |     spice_log(G_LOG_LEVEL_CRITICAL, SPICE_STRLOC, __FUNCTION__, "" format, ## __VA_ARGS__); \
          |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    ./fallthrough.c:8:25: note: in expansion of macro 'spice_critical'
        8 |                         spice_critical("foo");
          |                         ^~~~~~~~~~~~~~
    ./fallthrough.c:9:17: note: here
        9 |                 default:
          |                 ^~~~~~~
    
    Signed-off-by: Christophe Fergeau <cfergeau at redhat.com>
    Acked-by: Frediano Ziglio <fziglio at redhat.com>

diff --git a/common/log.h b/common/log.h
index 7c67e7a..201c87a 100644
--- a/common/log.h
+++ b/common/log.h
@@ -39,16 +39,18 @@ void spice_log(GLogLevelFlags log_level,
                const char *format,
                ...) G_GNUC_PRINTF(4, 5);
 
+/* FIXME: name is misleading, this aborts.. */
 #define spice_return_if_fail(x) G_STMT_START {                          \
     if G_LIKELY(x) { } else {                                           \
-        spice_log(G_LOG_LEVEL_CRITICAL, SPICE_STRLOC, G_STRFUNC, "condition `%s' failed", #x); \
+        spice_critical("condition `%s' failed", #x);                    \
         return;                                                         \
     }                                                                   \
 } G_STMT_END
 
+/* FIXME: name is misleading, this aborts.. */
 #define spice_return_val_if_fail(x, val) G_STMT_START {                 \
     if G_LIKELY(x) { } else {                                           \
-        spice_log(G_LOG_LEVEL_CRITICAL, SPICE_STRLOC, __FUNCTION__, "condition `%s' failed", #x); \
+        spice_critical("condition `%s' failed", #x);                    \
         return (val);                                                   \
     }                                                                   \
 } G_STMT_END
@@ -71,10 +73,12 @@ void spice_log(GLogLevelFlags log_level,
 
 #define spice_critical(format, ...) G_STMT_START {                          \
     spice_log(G_LOG_LEVEL_CRITICAL, SPICE_STRLOC, __FUNCTION__, "" format, ## __VA_ARGS__); \
+    SPICE_UNREACHABLE;                                                                      \
 } G_STMT_END
 
 #define spice_error(format, ...) G_STMT_START {                         \
     spice_log(G_LOG_LEVEL_ERROR, SPICE_STRLOC, __FUNCTION__, "" format, ## __VA_ARGS__); \
+    SPICE_UNREACHABLE;                                                                   \
 } G_STMT_END
 
 #define spice_warn_if_fail(x) G_STMT_START {            \
diff --git a/common/macros.h b/common/macros.h
index 2f24ada..92cd82c 100644
--- a/common/macros.h
+++ b/common/macros.h
@@ -55,4 +55,12 @@
 
 #define SPICE_VERIFY(cond) verify_expr(cond, (void)1)
 
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+#define SPICE_UNREACHABLE __builtin_unreachable()
+#elif defined(_MSC_VER)
+#define SPICE_UNREACHABLE __assume(0)
+#else
+#define SPICE_UNREACHABLE for(;;) continue
+#endif
+
 #endif // H_SPICE_COMMON_MACROS