1 files changed, 70 insertions, 0 deletions
diff --git a/util/path.c b/util/path.c
new file mode 100644
index 000000000..8e174eb43
--- /dev/null
+++ b/util/path.c
@@ -0,0 +1,70 @@
+/* Code to mangle pathnames into those matching a given prefix.
+   eg. open("/lib/foo.so") => open("/usr/gnemul/i386-linux/lib/foo.so");
+
+   The assumption is that this area does not change.
+*/
+#include "qemu/osdep.h"
+#include <sys/param.h>
+#include <dirent.h>
+#include "qemu/cutils.h"
+#include "qemu/path.h"
+#include "qemu/thread.h"
+
+static const char *base;
+static GHashTable *hash;
+static QemuMutex lock;
+
+void init_paths(const char *prefix)
+{
+    if (prefix[0] == '\0' || !strcmp(prefix, "/")) {
+        return;
+    }
+
+    if (prefix[0] == '/') {
+        base = g_strdup(prefix);
+    } else {
+        char *cwd = g_get_current_dir();
+        base = g_build_filename(cwd, prefix, NULL);
+        g_free(cwd);
+    }
+
+    hash = g_hash_table_new(g_str_hash, g_str_equal);
+    qemu_mutex_init(&lock);
+}
+
+/* Look for path in emulation dir, otherwise return name. */
+const char *path(const char *name)
+{
+    gpointer key, value;
+    const char *ret;
+
+    /* Only do absolute paths: quick and dirty, but should mostly be OK.  */
+    if (!base || !name || name[0] != '/') {
+        return name;
+    }
+
+    qemu_mutex_lock(&lock);
+
+    /* Have we looked up this file before?  */
+    if (g_hash_table_lookup_extended(hash, name, &key, &value)) {
+        ret = value ? value : name;
+    } else {
+        char *save = g_strdup(name);
+        char *full = g_build_filename(base, name, NULL);
+
+        /* Look for the path; record the result, pass or fail.  */
+        if (access(full, F_OK) == 0) {
+            /* Exists.  */
+            g_hash_table_insert(hash, save, full);
+            ret = full;
+        } else {
+            /* Does not exist.  */
+            g_free(full);
+            g_hash_table_insert(hash, save, NULL);
+            ret = name;
+        }
+    }
+
+    qemu_mutex_unlock(&lock);
+    return ret;
+}