[Qemu-devel] [PATCH v3] Introduce format string for pid_t

[Andreas Färber]

BeOS and Haiku on i386 use long for 32-bit types, including pid_t.
Using %d with pid_t therefore results in a warning.

Unfortunately POSIX:2008 does not define a PRId* string for pid_t.

In some places pid_t was previously casted to long and %ld hardcoded.
The predecessor of this patch added another upcast for the simpletrace
filename but was not applied to date.

Since new uses of pid_t with %d keep creeping in, let's instead define
an OS-dependent format string and use that consistently.

Cc: Stefan Hajnoczi <address@hidden>
Cc: Blue Swirl <address@hidden>
Cc: Ingo Weinhold <address@hidden>
Cc: Gleb Natapov <address@hidden>
Signed-off-by: Andreas Färber <address@hidden>
---
 v2: Use %ld and long instead of %lu for Haiku for x86_64 compatibility.
 
 configure  |    2 +-
 os-posix.c |    2 +-
 os-win32.c |    2 +-
 osdep.h    |    6 ++++++
 vl.c       |    2 +-
 5 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/configure b/configure
index a318d37..0f2b6bf 100755
--- a/configure
+++ b/configure
@@ -3037,7 +3037,7 @@ if test "$trace_backend" = "simple"; then
 fi
 # Set the appropriate trace file.
 if test "$trace_backend" = "simple"; then
-  trace_file="\"$trace_file-%u\""
+  trace_file="\"$trace_file-\" FMT_pid"
 fi
 if test "$trace_backend" = "dtrace" -a "$trace_backend_stap" = "yes" ; then
   echo "CONFIG_SYSTEMTAP_TRACE=y" >> $config_host_mak
diff --git a/os-posix.c b/os-posix.c
index 3204197..7dfb278 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -368,7 +368,7 @@ int qemu_create_pidfile(const char *filename)
     if (lockf(fd, F_TLOCK, 0) == -1) {
         return -1;
     }
-    len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());
+    len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
     if (write(fd, buffer, len) != len) {
         return -1;
     }
diff --git a/os-win32.c b/os-win32.c
index d6d54c6..b6652af 100644
--- a/os-win32.c
+++ b/os-win32.c
@@ -258,7 +258,7 @@ int qemu_create_pidfile(const char *filename)
     if (file == INVALID_HANDLE_VALUE) {
         return -1;
     }
-    len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());
+    len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid());
     ret = WriteFileEx(file, (LPCVOID)buffer, (DWORD)len,
                      &overlap, NULL);
     if (ret == 0) {
diff --git a/osdep.h b/osdep.h
index 970d767..97d167a 100644
--- a/osdep.h
+++ b/osdep.h
@@ -127,6 +127,12 @@ void qemu_vfree(void *ptr);
 
 int qemu_madvise(void *addr, size_t len, int advice);
 
+#if defined(__HAIKU__) && defined(__i386__)
+#define FMT_pid "%ld"
+#else
+#define FMT_pid "%d"
+#endif
+
 int qemu_create_pidfile(const char *filename);
 int qemu_get_thread_id(void);
 
diff --git a/vl.c b/vl.c
index b362871..b7b98f0 100644
--- a/vl.c
+++ b/vl.c
@@ -1191,7 +1191,7 @@ void qemu_kill_report(void)
              */
             fputc('\n', stderr);
         } else {
-            fprintf(stderr, " from pid %d\n", shutdown_pid);
+            fprintf(stderr, " from pid " FMT_pid "\n", shutdown_pid);
         }
         shutdown_signal = -1;
     }
-- 
1.7.5.2.317.g391b14