[Qemu-devel] [PATCH v18 01/10] util: Split out qemu_exec_dir from os_find_datadir

[Paolo Bonzini <pbonzini@redhat.com>]

From: Fam Zheng <famz@redhat.com>

This can be reused by module loading routines.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 include/qemu/osdep.h |  4 ++++
 os-posix.c           | 40 ++++++----------------------------------
 os-win32.c           | 19 +------------------
 util/oslib-posix.c   | 45 +++++++++++++++++++++++++++++++++++++++++++++
 util/oslib-win32.c   | 24 ++++++++++++++++++++++++
 5 files changed, 80 insertions(+), 52 deletions(-)

diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index eac7172..9e329ca 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -215,6 +215,10 @@ bool fips_get_state(void);
  */
 char *qemu_get_local_state_pathname(const char *relative_pathname);
 
+/* Find program directory with best effort. Try platform API first, then parse
+ * argv0 if it's not NULL. The returned string needs to be g_free'ed */
+char *qemu_exec_dir(const char *argv0);
+
 /**
  * qemu_getauxval:
  * @type: the auxiliary vector key to lookup
diff --git a/os-posix.c b/os-posix.c
index d39261d..c5e0722 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -86,44 +86,15 @@ void os_setup_signal_handling(void)
 #define BUILD_SUFFIX "/pc-bios"
 char *os_find_datadir(const char *argv0)
 {
-    char *dir;
-    char *p = NULL;
+    char *dir, *exec_dir;
     char *res;
-    char buf[PATH_MAX];
     size_t max_len;
 
-#if defined(__linux__)
-    {
-        int len;
-        len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
-        if (len > 0) {
-            buf[len] = 0;
-            p = buf;
-        }
-    }
-#elif defined(__FreeBSD__)
-    {
-        static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
-        size_t len = sizeof(buf) - 1;
-
-        *buf = '\0';
-        if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
-            *buf) {
-            buf[sizeof(buf) - 1] = '\0';
-            p = buf;
-        }
-    }
-#endif
-    /* If we don't have any way of figuring out the actual executable
-       location then try argv[0].  */
-    if (!p) {
-        p = realpath(argv0, buf);
-        if (!p) {
-            return NULL;
-        }
+    exec_dir = qemu_exec_dir(argv0);
+    if (exec_dir == NULL) {
+        return NULL;
     }
-    dir = dirname(p);
-    dir = dirname(dir);
+    dir = dirname(exec_dir);
 
     max_len = strlen(dir) +
         MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1;
@@ -137,6 +108,7 @@ char *os_find_datadir(const char *argv0)
         }
     }
 
+    g_free(exec_dir);
     return res;
 }
 #undef SHARE_SUFFIX
diff --git a/os-win32.c b/os-win32.c
index 50b7f6f..564d5b4 100644
--- a/os-win32.c
+++ b/os-win32.c
@@ -86,24 +86,7 @@ void os_setup_early_signal_handling(void)
 /* Look for support files in the same directory as the executable.  */
 char *os_find_datadir(const char *argv0)
 {
-    char *p;
-    char buf[MAX_PATH];
-    DWORD len;
-
-    len = GetModuleFileName(NULL, buf, sizeof(buf) - 1);
-    if (len == 0) {
-        return NULL;
-    }
-
-    buf[len] = 0;
-    p = buf + len - 1;
-    while (p != buf && *p != '\\')
-        p--;
-    *p = 0;
-    if (access(buf, R_OK) == 0) {
-        return g_strdup(buf);
-    }
-    return NULL;
+    return qemu_exec_dir(argv0);
 }
 
 void os_set_line_buffering(void)
diff --git a/util/oslib-posix.c b/util/oslib-posix.c
index d5dca47..372b2f9 100644
--- a/util/oslib-posix.c
+++ b/util/oslib-posix.c
@@ -57,6 +57,7 @@ extern int daemon(int, int);
 #include "trace.h"
 #include "qemu/sockets.h"
 #include <sys/mman.h>
+#include <libgen.h>
 
 #ifdef CONFIG_LINUX
 #include <sys/syscall.h>
@@ -274,3 +275,47 @@ void qemu_set_tty_echo(int fd, bool echo)
 
     tcsetattr(fd, TCSANOW, &tty);
 }
+
+char *qemu_exec_dir(const char *argv0)
+{
+    char *dir;
+    char *p = NULL;
+    char buf[PATH_MAX];
+
+#if defined(__linux__)
+    {
+        int len;
+        len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
+        if (len > 0) {
+            buf[len] = 0;
+            p = buf;
+        }
+    }
+#elif defined(__FreeBSD__)
+    {
+        static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
+        size_t len = sizeof(buf) - 1;
+
+        *buf = '\0';
+        if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
+            *buf) {
+            buf[sizeof(buf) - 1] = '\0';
+            p = buf;
+        }
+    }
+#endif
+    /* If we don't have any way of figuring out the actual executable
+       location then try argv[0].  */
+    if (!p) {
+        if (!argv0) {
+            return NULL;
+        }
+        p = realpath(argv0, buf);
+        if (!p) {
+            return NULL;
+        }
+    }
+    dir = dirname(p);
+
+    return g_strdup(dir);
+}
diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index 50be044..9ce22a1 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -208,3 +208,27 @@ void qemu_set_tty_echo(int fd, bool echo)
                        dwMode & ~(ENABLE_ECHO_INPUT | ENABLE_LINE_INPUT));
     }
 }
+
+char *qemu_exec_dir(const char *argv0)
+{
+
+    char *p;
+    char buf[MAX_PATH];
+    DWORD len;
+
+    len = GetModuleFileName(NULL, buf, sizeof(buf) - 1);
+    if (len == 0) {
+        return NULL;
+    }
+
+    buf[len] = 0;
+    p = buf + len - 1;
+    while (p != buf && *p != '\\') {
+        p--;
+    }
+    *p = 0;
+    if (access(buf, R_OK) == 0) {
+        return g_strdup(buf);
+    }
+    return NULL;
+}
-- 
1.8.3.1