2004-05-28 Gonzalo Paniagua Javier <gonzalo@ximian.com>
[mono.git] / mono / metadata / assembly.c
index 229a50c86e60c97ef7e7c2d3db0e2de061edb170..d5b4fdcd8d6b19e78c1aad09fb5f1364cce91e89 100644 (file)
 #ifdef WITH_BUNDLE
 #include "mono-bundle.h"
 #endif
+#include <mono/metadata/loader.h>
+#include <mono/metadata/tabledefs.h>
 #include <mono/io-layer/io-layer.h>
+#include <mono/utils/mono-uri.h>
+#include <mono/metadata/mono-config.h>
+#include <mono/utils/mono-digest.h>
+#ifdef PLATFORM_WIN32
+#include <mono/os/util.h>
+#endif
 
 /* the default search path is just MONO_ASSEMBLIES */
 static const char*
@@ -42,33 +50,104 @@ static MonoAssembly *corlib;
 /* This protects loaded_assemblies and image->references */
 static CRITICAL_SECTION assemblies_mutex;
 
-#ifdef PLATFORM_WIN32
+/* A hastable of thread->assembly list mappings */
+static GHashTable *assemblies_loading;
 
-static void
-init_default_path (void)
+static char **extra_gac_paths = NULL;
+
+static gchar*
+encode_public_tok (const guchar *token, gint32 len)
 {
+       static gchar allowed [] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
+       gchar *res;
        int i;
 
-       default_path [0] = g_strdup (MONO_ASSEMBLIES);
-       for (i = strlen (MONO_ASSEMBLIES) - 1; i >= 0; i--) {
-               if (default_path [0][i] == '/')
-                       ((char*) default_path [0])[i] = '\\';
+       res = g_malloc (len * 2 + 1);
+       for (i = 0; i < len; i++) {
+               res [i * 2] = allowed [token [i] >> 4];
+               res [i * 2 + 1] = allowed [token [i] & 0xF];
        }
+       res [len * 2] = 0;
+       return res;
 }
-#endif
 
 static void
-check_env (void) {
+check_path_env (void) {
        const char *path;
        char **splitted;
        
-       path = getenv ("MONO_PATH");
+       path = g_getenv ("MONO_PATH");
        if (!path)
                return;
+
        splitted = g_strsplit (path, G_SEARCHPATH_SEPARATOR_S, 1000);
        if (assemblies_path)
                g_strfreev (assemblies_path);
        assemblies_path = splitted;
+       if (g_getenv ("MONO_DEBUG") == NULL)
+               return;
+
+       while (*splitted) {
+               if (**splitted && !g_file_test (*splitted, G_FILE_TEST_IS_DIR))
+                       g_warning ("'%s' in MONO_PATH doesn't exist or has wrong permissions.", *splitted);
+
+               splitted++;
+       }
+}
+
+static void
+check_extra_gac_path_env (void) {
+       const char *path;
+       char **splitted;
+       
+       path = g_getenv ("MONO_GAC_PATH");
+       if (!path)
+               return;
+
+       splitted = g_strsplit (path, G_SEARCHPATH_SEPARATOR_S, 1000);
+       if (extra_gac_paths)
+               g_strfreev (extra_gac_paths);
+       extra_gac_paths = splitted;
+       if (g_getenv ("MONO_DEBUG") == NULL)
+               return;
+
+       while (*splitted) {
+               if (**splitted && !g_file_test (*splitted, G_FILE_TEST_IS_DIR))
+                       g_warning ("'%s' in MONO_GAC_PATH doesn't exist or has wrong permissions.", *splitted);
+
+               splitted++;
+       }
+}
+
+static gboolean
+mono_assembly_names_equal (MonoAssemblyName *l, MonoAssemblyName *r)
+{
+       if (!l->name || !r->name)
+               return FALSE;
+
+       if (strcmp (l->name, r->name))
+               return FALSE;
+
+        /*
+         * simply compare names until some other issues are resolved
+         * (version info not getting set correctly for custom
+         * attributes).
+         */
+        /*
+       if (l->major != r->major || l->minor != r->minor ||
+                       l->build != r->build || l->revision != r->revision)
+               return FALSE;
+
+       if (!l->public_tok_value && !r->public_tok_value)
+               return TRUE;
+
+       if ((l->public_tok_value && !r->public_tok_value) || (!l->public_tok_value && r->public_tok_value))
+               return FALSE;
+
+       if (strcmp (l->public_tok_value, r->public_tok_value))
+               return FALSE;
+        */
+       return TRUE;
 }
 
 /* assemblies_mutex must be held by the caller */
@@ -77,18 +156,31 @@ search_loaded (MonoAssemblyName* aname)
 {
        GList *tmp;
        MonoAssembly *ass;
+       GList *loading;
        
        for (tmp = loaded_assemblies; tmp; tmp = tmp->next) {
                ass = tmp->data;
-               if (!ass->aname.name)
-                       continue;
-               /* we just compare the name, but later we'll do all the checks */
                /* g_print ("compare %s %s\n", aname->name, ass->aname.name); */
-               if (strcmp (aname->name, ass->aname.name))
+               if (!mono_assembly_names_equal (aname, &ass->aname))
                        continue;
                /* g_print ("success\n"); */
+
                return ass;
        }
+
+       /*
+        * The assembly might be under load by this thread. In this case, it is
+        * safe to return an incomplete instance to prevent loops.
+        */
+       loading = g_hash_table_lookup (assemblies_loading, GetCurrentThread ());
+       for (tmp = loading; tmp; tmp = tmp->next) {
+               ass = tmp->data;
+               if (!mono_assembly_names_equal (aname, &ass->aname))
+                       continue;
+
+               return ass;
+       }
+
        return NULL;
 }
 
@@ -128,6 +220,12 @@ mono_assembly_setrootdir (const char *root_dir)
        default_path [0] = g_strdup (root_dir);
 }
 
+G_CONST_RETURN gchar *
+mono_assembly_getrootdir (void)
+{
+       return default_path [0];
+}
+
 /**
  * mono_assemblies_init:
  *
@@ -137,24 +235,83 @@ void
 mono_assemblies_init (void)
 {
 #ifdef PLATFORM_WIN32
-       init_default_path ();
+       mono_set_rootdir ();
 #endif
 
-       check_env ();
+       check_path_env ();
+       check_extra_gac_path_env ();
 
        InitializeCriticalSection (&assemblies_mutex);
+
+       assemblies_loading = g_hash_table_new (NULL, NULL);
+}
+
+gboolean
+mono_assembly_fill_assembly_name (MonoImage *image, MonoAssemblyName *aname)
+{
+       MonoTableInfo *t = &image->tables [MONO_TABLE_ASSEMBLY];
+       guint32 cols [MONO_ASSEMBLY_SIZE];
+
+       if (!t->rows)
+               return FALSE;
+
+       mono_metadata_decode_row (t, 0, cols, MONO_ASSEMBLY_SIZE);
+
+       aname->hash_len = 0;
+       aname->hash_value = NULL;
+       aname->name = mono_metadata_string_heap (image, cols [MONO_ASSEMBLY_NAME]);
+       aname->culture = mono_metadata_string_heap (image, cols [MONO_ASSEMBLY_CULTURE]);
+       aname->flags = cols [MONO_ASSEMBLY_FLAGS];
+       aname->major = cols [MONO_ASSEMBLY_MAJOR_VERSION];
+       aname->minor = cols [MONO_ASSEMBLY_MINOR_VERSION];
+       aname->build = cols [MONO_ASSEMBLY_BUILD_NUMBER];
+       aname->revision = cols [MONO_ASSEMBLY_REV_NUMBER];
+       aname->hash_alg = cols [MONO_ASSEMBLY_HASH_ALG];
+       if (cols [MONO_ASSEMBLY_PUBLIC_KEY])
+               aname->public_key = mono_metadata_blob_heap (image, cols [MONO_ASSEMBLY_PUBLIC_KEY]);
+       else
+               aname->public_key = 0;
+
+       return TRUE;
+}
+
+static gchar*
+assemblyref_public_tok (MonoImage *image, guint32 key_index, guint32 flags)
+{
+       const gchar *public_tok;
+       int len;
+
+       public_tok = mono_metadata_blob_heap (image, key_index);
+       len = mono_metadata_decode_blob_size (public_tok, &public_tok);
+
+       if (flags & ASSEMBLYREF_FULL_PUBLIC_KEY_FLAG) {
+               gchar token [8];
+               mono_digest_get_public_token (token, public_tok, len);
+               return encode_public_tok (token, 8);
+       }
+
+       return encode_public_tok (public_tok, len);
 }
 
 void
-mono_image_load_references (MonoImage *image, MonoImageOpenStatus *status) {
+mono_assembly_load_references (MonoImage *image, MonoImageOpenStatus *status)
+{
        MonoTableInfo *t;
        guint32 cols [MONO_ASSEMBLYREF_SIZE];
        const char *hash;
        int i;
-       MonoAssembly **references;
+       MonoAssembly **references = NULL;
 
        *status = MONO_IMAGE_OK;
-       if (image->references)
+       
+       /*
+        * image->references is shared between threads, so we need to access
+        * it inside a critical section.
+        */
+       EnterCriticalSection (&assemblies_mutex);
+       references = image->references;
+       LeaveCriticalSection (&assemblies_mutex);
+       if (references)
                return;
 
        t = &image->tables [MONO_TABLE_ASSEMBLYREF];
@@ -180,28 +337,83 @@ mono_image_load_references (MonoImage *image, MonoImageOpenStatus *status) {
                aname.build = cols [MONO_ASSEMBLYREF_BUILD_NUMBER];
                aname.revision = cols [MONO_ASSEMBLYREF_REV_NUMBER];
 
+               if (cols [MONO_ASSEMBLYREF_PUBLIC_KEY]) {
+                       aname.public_tok_value = assemblyref_public_tok (image,
+                                       cols [MONO_ASSEMBLYREF_PUBLIC_KEY], aname.flags);
+               } else {
+                       aname.public_tok_value = NULL;
+               } 
+
                references [i] = mono_assembly_load (&aname, image->assembly->basedir, status);
+
                if (references [i] == NULL){
                        int j;
-                       
-                       for (j = 0; j < i; j++)
-                               mono_assembly_close (references [j]);
-                       g_free (references);
 
-                       g_warning ("Could not find assembly %s", aname.name);
-                       *status = MONO_IMAGE_MISSING_ASSEMBLYREF;
-                       return;
+                       /*
+                       ** Temporary work around: any System.* which are 3300 build, will get
+                       ** remapped, this is to keep old applications running that might have
+                       ** been linked against our 5000 API, before we were strongnamed, and
+                       ** hence were labeled as 3300 builds by reflection.c
+                       */
+                       if (aname.build == 3300 && strncmp (aname.name, "System", 6) == 0){
+                               aname.build = 5000;
+                               
+                               references [i] = mono_assembly_load (&aname, image->assembly->basedir, status);
+                       }
+                       if (references [i] != NULL){
+                               if (g_getenv ("MONO_SILENT_WARNING") == NULL)
+                                       g_printerr ("Compat mode: the request from %s to load %s was remapped (http://www.go-mono.com/remap.html)\n",
+                                                image->name, aname.name);
+                               
+                       } else {
+                       
+                               for (j = 0; j < i; j++)
+                                       mono_assembly_close (references [j]);
+                               g_free (references);
+                               
+                               g_warning ("Could not find assembly %s, references from %s (assemblyref_index=%d)\n"
+                                          "     Major/Minor: %d,%d\n"
+                                          "     Build:       %d,%d\n"
+                                          "     Token:       %s\n",
+                                          aname.name, image->name, i,
+                                          aname.major, aname.minor, aname.build, aname.revision,
+                                          aname.public_tok_value);
+                               *status = MONO_IMAGE_MISSING_ASSEMBLYREF;
+                               return;
+                       }
                }
+
+               /* 
+                * This check is disabled since lots of people seem to have an older
+                * corlib which triggers this.
+                */
+               /* 
+               if (image->references [i]->image == image)
+                       g_error ("Error: Assembly %s references itself", image->name);
+               */
        }
        references [i] = NULL;
 
+       /* resolve assembly references for modules */
+       t = &image->tables [MONO_TABLE_MODULEREF];
+       for (i = 0; i < t->rows; i++){
+               if (image->modules [i]) {
+                       image->modules [i]->assembly = image->assembly;
+                       mono_assembly_load_references (image->modules [i], status);
+               }
+       }
+
        EnterCriticalSection (&assemblies_mutex);
-       if (image->references)
-               /* Somebody got in before us */
-               g_free (references);
-       else
+       if (!image->references)
                image->references = references;
        LeaveCriticalSection (&assemblies_mutex);
+
+       if (image->references != references) {
+               /* Somebody loaded it before us */
+               for (i = 0; i < t->rows; i++)
+                       mono_assembly_close (references [i]);
+               g_free (references);
+       }
 }
 
 typedef struct AssemblyLoadHook AssemblyLoadHook;
@@ -282,7 +494,7 @@ absolute_dir (const gchar *filename)
        gchar *mixed;
        gchar **parts;
        gchar *part;
-       GSList *list, *tmp;
+       GList *list, *tmp;
        GString *result;
        gchar *res;
        gint i;
@@ -303,14 +515,14 @@ absolute_dir (const gchar *filename)
 
                if (!strcmp (part, "..")) {
                        if (list && list->next) /* Don't remove root */
-                               list = g_slist_delete_link (list, list);
+                               list = g_list_delete_link (list, list);
                } else {
-                       list = g_slist_prepend (list, part);
+                       list = g_list_prepend (list, part);
                }
        }
 
        result = g_string_new ("");
-       list = g_slist_reverse (list);
+       list = g_list_reverse (list);
 
        /* Ignores last data pointer, which should be the filename */
        for (tmp = list; tmp && tmp->next != NULL; tmp = tmp->next)
@@ -320,7 +532,7 @@ absolute_dir (const gchar *filename)
        
        res = result->str;
        g_string_free (result, FALSE);
-       g_slist_free (list);
+       g_list_free (list);
        g_strfreev (parts);
        if (*res == '\0') {
                g_free (res);
@@ -343,12 +555,8 @@ do_mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
        
        if (dot)
                *dot = 0;
-       if (strcmp (name, "corlib") == 0) {
-               g_free (name);
-               name = g_strdup ("mscorlib");
-       }
-       /* we do a very simple search for bundled assemblies: it's not a general purpouse
-        * assembly loading mechanism.
+       /* we do a very simple search for bundled assemblies: it's not a general 
+        * purpose assembly loading mechanism.
         */
        EnterCriticalSection (&assemblies_mutex);
        for (tmp = loaded_assemblies; tmp; tmp = tmp->next) {
@@ -360,18 +568,24 @@ do_mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
                image = ass->image;
                break;
        }
-       LeaveCriticalSection (&assemblies_mutex);
+
        for (i = 0; !image && bundled_assemblies [i]; ++i) {
                if (strcmp (bundled_assemblies [i]->name, name) == 0) {
                        image = mono_image_open_from_data ((char*)bundled_assemblies [i]->data, bundled_assemblies [i]->size, FALSE, status);
                        break;
                }
        }
+       LeaveCriticalSection (&assemblies_mutex);
        g_free (name);
-       if (image)
+       if (image) {
+               mono_image_addref (image);
                return image;
+       }
 #endif
+       EnterCriticalSection (&assemblies_mutex);
        image = mono_image_open (filename, status);
+       LeaveCriticalSection (&assemblies_mutex);
+       
        return image;
 }
 
@@ -389,12 +603,8 @@ do_mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
 MonoAssembly *
 mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
 {
-       MonoAssembly *ass, *ass2;
        MonoImage *image;
-       MonoTableInfo *t;
-       guint32 cols [MONO_ASSEMBLY_SIZE];
-       int i;
-       char *base_dir, *aot_name;
+       MonoAssembly *ass;
        MonoImageOpenStatus def_status;
        gchar *fname;
        
@@ -407,6 +617,7 @@ mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
        if (strncmp (filename, "file://", 7) == 0) {
                GError *error = NULL;
                gchar *uri = (gchar *) filename;
+               gchar *tmpuri;
 
                /*
                 * MS allows file://c:/... and fails on file://localhost/c:/... 
@@ -414,10 +625,14 @@ mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
                 */
                if (uri [7] != '/')
                        uri = g_strdup_printf ("file:///%s", uri + 7);
-               
+       
+               tmpuri = uri;
+               uri = mono_escape_uri_string (tmpuri);
                fname = g_filename_from_uri (uri, NULL, &error);
-               if (uri != filename)
-                       g_free (uri);
+               g_free (uri);
+
+               if (tmpuri != filename)
+                       g_free (tmpuri);
 
                if (error != NULL) {
                        g_warning ("%s\n", error->message);
@@ -437,9 +652,28 @@ mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
                return NULL;
        }
 
+       ass = mono_assembly_load_from (image, fname, status);
+
+       mono_config_for_assembly (ass->image);
+
+       g_free (fname);
+
+       return ass;
+}
+
+MonoAssembly *
+mono_assembly_load_from (MonoImage *image, const char*fname, 
+                        MonoImageOpenStatus *status)
+{
+       MonoAssembly *ass, *ass2;
+       char *base_dir;
+       GList *loading;
+
 #if defined (PLATFORM_WIN32)
        {
                gchar *tmp_fn;
+               int i;
+
                tmp_fn = g_strdup (fname);
                for (i = strlen (tmp_fn) - 1; i >= 0; i--) {
                        if (tmp_fn [i] == '/')
@@ -453,6 +687,14 @@ mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
        base_dir = absolute_dir (fname);
 #endif
 
+       /*
+        * To avoid deadlocks and scalability problems, we load assemblies outside
+        * the assembly lock. This means that multiple threads might try to load
+        * the same assembly at the same time. The first one to load it completely
+        * "wins", the other threads free their copy and use the one loaded by
+        * the winning thread.
+        */
+
        /*
         * Create assembly struct, and enter it into the assembly cache
         */
@@ -460,36 +702,7 @@ mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
        ass->basedir = base_dir;
        ass->image = image;
 
-       /* load aot compiled module */
-       aot_name = g_strdup_printf ("%s.so", fname);
-       g_free (fname);
-       ass->aot_module = g_module_open (aot_name, G_MODULE_BIND_LAZY);
-       g_free (aot_name);
-
-       if (ass->aot_module) {
-               char *saved_guid = NULL;
-               g_module_symbol (ass->aot_module, "mono_assembly_guid", (gpointer *) &saved_guid);
-
-               if (!saved_guid || strcmp (image->guid, saved_guid)) {
-                       g_module_close (ass->aot_module);
-                       ass->aot_module = NULL;
-               }
-       }
-
-       t = &image->tables [MONO_TABLE_ASSEMBLY];
-       if (t->rows) {
-               mono_metadata_decode_row (t, 0, cols, MONO_ASSEMBLY_SIZE);
-               
-               ass->aname.hash_len = 0;
-               ass->aname.hash_value = NULL;
-               ass->aname.name = mono_metadata_string_heap (image, cols [MONO_ASSEMBLY_NAME]);
-               ass->aname.culture = mono_metadata_string_heap (image, cols [MONO_ASSEMBLY_CULTURE]);
-               ass->aname.flags = cols [MONO_ASSEMBLY_FLAGS];
-               ass->aname.major = cols [MONO_ASSEMBLY_MAJOR_VERSION];
-               ass->aname.minor = cols [MONO_ASSEMBLY_MINOR_VERSION];
-               ass->aname.build = cols [MONO_ASSEMBLY_BUILD_NUMBER];
-               ass->aname.revision = cols [MONO_ASSEMBLY_REV_NUMBER];
-       }
+       mono_assembly_fill_assembly_name (image, &ass->aname);
 
        /* 
         * Atomically search the loaded list and add ourselves to it if necessary.
@@ -500,72 +713,219 @@ mono_assembly_open (const char *filename, MonoImageOpenStatus *status)
                if ((ass2 = search_loaded (&ass->aname))) {
                        g_free (ass);
                        g_free (base_dir);
+                       mono_image_close (image);
                        *status = MONO_IMAGE_OK;
                        LeaveCriticalSection (&assemblies_mutex);
                        return ass2;
                }
-       /* register right away to prevent loops */
-       loaded_assemblies = g_list_prepend (loaded_assemblies, ass);
+       loading = g_hash_table_lookup (assemblies_loading, GetCurrentThread ());
+       loading = g_list_prepend (loading, ass);
+       g_hash_table_insert (assemblies_loading, GetCurrentThread (), loading);
        LeaveCriticalSection (&assemblies_mutex);
 
        image->assembly = ass;
 
-       mono_image_load_references (image, status);
+       /*
+        * We load referenced assemblies outside the lock to prevent deadlocks
+        * with regards to preload hooks.
+        */
+       mono_assembly_load_references (image, status);
+
+       EnterCriticalSection (&assemblies_mutex);
+
+       loading = g_hash_table_lookup (assemblies_loading, GetCurrentThread ());
+       loading = g_list_remove (loading, ass);
+       if (loading == NULL)
+               /* Prevent memory leaks */
+               g_hash_table_remove (assemblies_loading, GetCurrentThread ());
+       else
+               g_hash_table_insert (assemblies_loading, GetCurrentThread (), loading);
        if (*status != MONO_IMAGE_OK) {
-               /* FIXME: What happens when another thread already grabbed this
-                  assembly from the loaded_assemblies list ??? */
+               LeaveCriticalSection (&assemblies_mutex);
                mono_assembly_close (ass);
                return NULL;
        }
 
-       /* resolve assembly references for modules */
-       t = &image->tables [MONO_TABLE_MODULEREF];
-       for (i = 0; i < t->rows; i++){
-               if (image->modules [i]) {
-                       image->modules [i]->assembly = ass;
-                       mono_image_load_references (image->modules [i], status);
+       if (ass->aname.name) {
+               ass2 = search_loaded (&ass->aname);
+               if (ass2) {
+                       /* Somebody else has loaded the assembly before us */
+                       LeaveCriticalSection (&assemblies_mutex);
+                       mono_assembly_close (ass);
+                       return ass2;
                }
-               /* 
-                * FIXME: what do we do here? it could be a native dll...
-                * We should probably do lazy-loading of modules.
-                */
-               *status = MONO_IMAGE_OK;
        }
 
+       loaded_assemblies = g_list_prepend (loaded_assemblies, ass);
+       LeaveCriticalSection (&assemblies_mutex);
+
        mono_assembly_invoke_load_hook (ass);
 
        return ass;
 }
 
+static MonoAssembly*
+probe_for_partial_name (const char *basepath, const char *fullname, MonoImageOpenStatus *status)
+{
+       MonoAssembly *res = NULL;
+       gchar *fullpath;
+       GDir *dirhandle;
+       const char* direntry;
+
+       dirhandle = g_dir_open (basepath, 0, NULL);
+       if (!dirhandle)
+               return NULL;
+
+       while ((direntry = g_dir_read_name (dirhandle))) {
+               fullpath = g_build_path (G_DIR_SEPARATOR_S, basepath, direntry, fullname, NULL);
+               res = mono_assembly_open (fullpath, status);
+               g_free (fullpath);
+               if (res)
+                       break;
+       }
+       g_dir_close (dirhandle);
+
+       return res;
+}
+
+MonoAssembly*
+mono_assembly_load_with_partial_name (const char *name, MonoImageOpenStatus *status)
+{
+       MonoAssembly *res;
+       MonoAssemblyName aname;
+       gchar *fullname, *gacpath;
+       gchar **paths;
+
+       memset (&aname, 0, sizeof (MonoAssemblyName));
+       aname.name = name;
+
+       res = mono_assembly_loaded (&aname);
+
+       if (res)
+               return res;
+
+       fullname = g_strdup_printf ("%s.dll", name);
+
+       if (extra_gac_paths) {
+               paths = extra_gac_paths;
+               while (!res && *paths) {
+                       gacpath = g_build_path (G_DIR_SEPARATOR_S, *paths, "gac", name, NULL);
+                       res = probe_for_partial_name (gacpath, fullname, status);
+                       g_free (gacpath);
+                       paths++;
+               }
+       }
+
+       if (res) {
+               res->in_gac = TRUE;
+               g_free (fullname);
+               return res;
+               
+       }
+
+       gacpath = g_build_path (G_DIR_SEPARATOR_S, mono_assembly_getrootdir (), "mono", "gac", name, NULL);
+       res = probe_for_partial_name (gacpath, fullname, status);
+       g_free (gacpath);
+
+       if (res)
+               res->in_gac = TRUE;
+
+       g_free (fullname);
+
+       return res;
+}
+
+/**
+ * mono_assembly_load_from_gac
+ *
+ * @aname: The assembly name object
+ */
+static MonoAssembly*
+mono_assembly_load_from_gac (MonoAssemblyName *aname,  gchar *filename, MonoImageOpenStatus *status)
+{
+       MonoAssembly *result = NULL;
+       gchar *name, *version, *fullpath, *subpath;
+       gint32 len;
+       gchar **paths;
+
+       if (!aname->public_tok_value) {
+               return NULL;
+       }
+
+       if (strstr (aname->name, ".dll")) {
+               len = strlen (filename) - 4;
+               name = g_malloc (len);
+               strncpy (name, aname->name, len);
+       } else {
+               name = g_strdup (aname->name);
+       }
+
+       version = g_strdup_printf ("%d.%d.%d.%d_%s_%s", aname->major,
+                       aname->minor, aname->build, aname->revision,
+                       aname->culture == NULL ? "" : aname->culture,
+                       aname->public_tok_value);
+       
+       subpath = g_build_path (G_DIR_SEPARATOR_S, name, version, filename, NULL);
+       g_free (name);
+       g_free (version);
+
+       if (extra_gac_paths) {
+               paths = extra_gac_paths;
+               while (!result && *paths) {
+                       fullpath = g_build_path (G_DIR_SEPARATOR_S, *paths, "gac", subpath, NULL);
+                       result = mono_assembly_open (fullpath, status);
+                       g_free (fullpath);
+                       paths++;
+               }
+       }
+
+       if (result) {
+               result->in_gac = TRUE;
+               g_free (subpath);
+               return result;
+       }
+
+       fullpath = g_build_path (G_DIR_SEPARATOR_S, mono_assembly_getrootdir (),
+                       "mono", "gac", subpath, NULL);
+       result = mono_assembly_open (fullpath, status);
+       g_free (fullpath);
+
+       if (result)
+               result->in_gac = TRUE;
+       
+       g_free (subpath);
+
+       return result;
+}
+
+       
 MonoAssembly*
 mono_assembly_load (MonoAssemblyName *aname, const char *basedir, MonoImageOpenStatus *status)
 {
        MonoAssembly *result;
        char *fullpath, *filename;
 
-       check_env ();
-
        result = invoke_assembly_preload_hook (aname, assemblies_path);
        if (result)
                return result;
-
        /* g_print ("loading %s\n", aname->name); */
        /* special case corlib */
-       if ((strcmp (aname->name, "mscorlib") == 0) || (strcmp (aname->name, "corlib") == 0)) {
+       if (strcmp (aname->name, "mscorlib") == 0) {
                if (corlib) {
                        /* g_print ("corlib already loaded\n"); */
                        return corlib;
                }
                /* g_print ("corlib load\n"); */
                if (assemblies_path) {
-                       corlib = load_in_path (CORLIB_NAME, (const char**)assemblies_path, status);
+                       corlib = load_in_path ("mscorlib.dll", (const char**)assemblies_path, status);
                        if (corlib)
                                return corlib;
                }
-               corlib = load_in_path (CORLIB_NAME, default_path, status);
+               corlib = load_in_path ("mscorlib.dll", default_path, status);
                return corlib;
        }
        result = search_loaded (aname);
+
        if (result)
                return result;
        /* g_print ("%s not found in cache\n", aname->name); */
@@ -573,11 +933,19 @@ mono_assembly_load (MonoAssemblyName *aname, const char *basedir, MonoImageOpenS
                filename = g_strdup (aname->name);
        else
                filename = g_strconcat (aname->name, ".dll", NULL);
+
+       result = mono_assembly_load_from_gac (aname, filename, status);
+       if (result) {
+               g_free (filename);
+               return result;
+       }
+
        if (basedir) {
                fullpath = g_build_filename (basedir, filename, NULL);
                result = mono_assembly_open (fullpath, status);
                g_free (fullpath);
                if (result) {
+                       result->in_gac = FALSE;
                        g_free (filename);
                        return result;
                }
@@ -585,15 +953,31 @@ mono_assembly_load (MonoAssemblyName *aname, const char *basedir, MonoImageOpenS
        if (assemblies_path) {
                result = load_in_path (filename, (const char**)assemblies_path, status);
                if (result) {
+                       result->in_gac = FALSE;
                        g_free (filename);
                        return result;
                }
        }
        result = load_in_path (filename, default_path, status);
+       
+       if (result)
+               result->in_gac = FALSE;
        g_free (filename);
        return result;
 }
 
+MonoAssembly*
+mono_assembly_loaded (MonoAssemblyName *aname)
+{
+       MonoAssembly *res;
+
+       EnterCriticalSection (&assemblies_mutex);
+       res = search_loaded (aname);
+       LeaveCriticalSection (&assemblies_mutex);
+
+       return res;
+}
+
 void
 mono_assembly_close (MonoAssembly *assembly)
 {
@@ -615,13 +999,26 @@ mono_assembly_close (MonoAssembly *assembly)
                        mono_image_close (image->references [i]->image);
                g_free (image->references);
        }
-            
+
        mono_image_close (assembly->image);
 
        g_free (assembly->basedir);
        g_free (assembly);
 }
 
+MonoImage*
+mono_assembly_load_module (MonoAssembly *assembly, guint32 idx)
+{
+       MonoImageOpenStatus status;
+       MonoImage *module;
+
+       module = mono_image_load_file_for_image (assembly->image, idx);
+       if (module)
+               mono_assembly_load_references (module, &status);
+
+       return module;
+}
+
 void
 mono_assembly_foreach (GFunc func, gpointer user_data)
 {
@@ -656,3 +1053,5 @@ mono_assembly_get_main (void)
 {
        return(main_assembly);
 }
+
+