Invent structure tags for the storage.h abstractions.

Most of these were 'void *' because they weren't even reliably a
structure type underneath - the per-OS storage systems would directly
cast read/write/enum settings handles to and from random things like
FILE *, Unix DIR *, or Windows HKEY. So I've wrapped them in tiny
structs for the sake of having a sensible structure tag visible
elsewhere in the code.

7 files changed, 131 insertions, 97 deletions

diff --git a/defs.h b/defs.h
index 1bc8f9b8..ba61708b 100644
--- a/defs.h
+++ b/defs.h
@@ -61,6 +61,10 @@ typedef struct share_channel share_channel;
 
 typedef struct dlgparam dlgparam;
 
+typedef struct settings_w settings_w;
+typedef struct settings_r settings_r;
+typedef struct settings_e settings_e;
+
 /* Note indirection: for historical reasons (it used to be closer to
  * the OS socket type), the type that most code uses for a socket is
  * 'Socket', not 'Socket *'. So an implementation of Socket or Plug
diff --git a/putty.h b/putty.h
index 7b1f90e4..dd43e8c4 100644
--- a/putty.h
+++ b/putty.h
@@ -1074,9 +1074,9 @@ const struct Backend_vtable *backend_vt_from_name(const char *name);
 const struct Backend_vtable *backend_vt_from_proto(int proto);
 char *get_remote_username(Conf *conf); /* dynamically allocated */
 char *save_settings(const char *section, Conf *conf);
-void save_open_settings(void *sesskey, Conf *conf);
+void save_open_settings(settings_w *sesskey, Conf *conf);
 void load_settings(const char *section, Conf *conf);
-void load_open_settings(void *sesskey, Conf *conf);
+void load_open_settings(settings_r *sesskey, Conf *conf);
 void get_sesslist(struct sesslist *, int allocate);
 void do_defaults(const char *, Conf *);
 void registry_cleanup(void);
diff --git a/settings.c b/settings.c
index ecdb3a4b..ab735488 100644
--- a/settings.c
+++ b/settings.c
@@ -502,7 +502,7 @@ static void read_clip_setting(void *handle, const char *savekey,
 
 char *save_settings(const char *section, Conf *conf)
 {
-    void *sesskey;
+    struct settings_w *sesskey;
     char *errmsg;
 
     sesskey = open_settings_w(section, &errmsg);
@@ -513,7 +513,7 @@ char *save_settings(const char *section, Conf *conf)
     return NULL;
 }
 
-void save_open_settings(void *sesskey, Conf *conf)
+void save_open_settings(settings_w *sesskey, Conf *conf)
 {
     int i;
     const char *p;
@@ -760,7 +760,7 @@ void save_open_settings(void *sesskey, Conf *conf)
 
 void load_settings(const char *section, Conf *conf)
 {
-    void *sesskey;
+    settings_r *sesskey;
 
     sesskey = open_settings_r(section);
     load_open_settings(sesskey, conf);
@@ -770,7 +770,7 @@ void load_settings(const char *section, Conf *conf)
         add_session_to_jumplist(section);
 }
 
-void load_open_settings(void *sesskey, Conf *conf)
+void load_open_settings(settings_r *sesskey, Conf *conf)
 {
     int i;
     char *prot;
@@ -1242,7 +1242,7 @@ void get_sesslist(struct sesslist *list, int allocate)
     char otherbuf[2048];
     int buflen, bufsize, i;
     char *p, *ret;
-    void *handle;
+    settings_e *handle;
 
     if (allocate) {
 
diff --git a/storage.h b/storage.h
index 8e07ef0c..6186e91d 100644
--- a/storage.h
+++ b/storage.h
@@ -28,12 +28,14 @@
  * 
  * Any returned error message must be freed after use.
  */
-void *open_settings_w(const char *sessionname, char **errmsg);
-void write_setting_s(void *handle, const char *key, const char *value);
-void write_setting_i(void *handle, const char *key, int value);
-void write_setting_filename(void *handle, const char *key, Filename *value);
-void write_setting_fontspec(void *handle, const char *key, FontSpec *font);
-void close_settings_w(void *handle);
+settings_w *open_settings_w(const char *sessionname, char **errmsg);
+void write_setting_s(settings_w *handle, const char *key, const char *value);
+void write_setting_i(settings_w *handle, const char *key, int value);
+void write_setting_filename(settings_w *handle,
+                            const char *key, Filename *value);
+void write_setting_fontspec(settings_w *handle,
+                            const char *key, FontSpec *font);
+void close_settings_w(settings_w *handle);
 
 /*
  * Read a saved session. The caller is expected to call
@@ -51,12 +53,12 @@ void close_settings_w(void *handle);
  * should invent a sensible default. If an integer setting is not
  * present, read_setting_i() returns its provided default.
  */
-void *open_settings_r(const char *sessionname);
-char *read_setting_s(void *handle, const char *key);
-int read_setting_i(void *handle, const char *key, int defvalue);
-Filename *read_setting_filename(void *handle, const char *key);
-FontSpec *read_setting_fontspec(void *handle, const char *key);
-void close_settings_r(void *handle);
+settings_r *open_settings_r(const char *sessionname);
+char *read_setting_s(settings_r *handle, const char *key);
+int read_setting_i(settings_r *handle, const char *key, int defvalue);
+Filename *read_setting_filename(settings_r *handle, const char *key);
+FontSpec *read_setting_fontspec(settings_r *handle, const char *key);
+void close_settings_r(settings_r *handle);
 
 /*
  * Delete a whole saved session.
@@ -66,9 +68,9 @@ void del_settings(const char *sessionname);
 /*
  * Enumerate all saved sessions.
  */
-void *enum_settings_start(void);
-char *enum_settings_next(void *handle, char *buffer, int buflen);
-void enum_settings_finish(void *handle);
+settings_e *enum_settings_start(void);
+char *enum_settings_next(settings_e *handle, char *buffer, int buflen);
+void enum_settings_finish(settings_e *handle);
 
 /* ----------------------------------------------------------------------
  * Functions to access PuTTY's host key database.
diff --git a/unix/uxstore.c b/unix/uxstore.c
index 15801785..54a20b8a 100644
--- a/unix/uxstore.c
+++ b/unix/uxstore.c
@@ -218,7 +218,11 @@ static char *make_filename(int index, const char *subname)
     return ret;
 }
 
-void *open_settings_w(const char *sessionname, char **errmsg)
+struct settings_w {
+    FILE *fp;
+};
+
+settings_w *open_settings_w(const char *sessionname, char **errmsg)
 {
     char *filename, *err;
     FILE *fp;
@@ -256,25 +260,26 @@ void *open_settings_w(const char *sessionname, char **errmsg)
 	return NULL;                   /* can't open */
     }
     sfree(filename);
-    return fp;
+
+    settings_w *toret = snew(settings_w);
+    toret->fp = fp;
+    return toret;
 }
 
-void write_setting_s(void *handle, const char *key, const char *value)
+void write_setting_s(settings_w *handle, const char *key, const char *value)
 {
-    FILE *fp = (FILE *)handle;
-    fprintf(fp, "%s=%s\n", key, value);
+    fprintf(handle->fp, "%s=%s\n", key, value);
 }
 
-void write_setting_i(void *handle, const char *key, int value)
+void write_setting_i(settings_w *handle, const char *key, int value)
 {
-    FILE *fp = (FILE *)handle;
-    fprintf(fp, "%s=%d\n", key, value);
+    fprintf(handle->fp, "%s=%d\n", key, value);
 }
 
-void close_settings_w(void *handle)
+void close_settings_w(settings_w *handle)
 {
-    FILE *fp = (FILE *)handle;
-    fclose(fp);
+    fclose(handle->fp);
+    sfree(handle);
 }
 
 /*
@@ -347,12 +352,16 @@ const char *get_setting(const char *key)
     return x_get_default(key);
 }
 
-void *open_settings_r(const char *sessionname)
+struct settings_r {
+    tree234 *t;
+};
+
+settings_r *open_settings_r(const char *sessionname)
 {
     char *filename;
     FILE *fp;
     char *line;
-    tree234 *ret;
+    settings_r *toret;
 
     filename = make_filename(INDEX_SESSION, sessionname);
     fp = fopen(filename, "r");
@@ -360,7 +369,8 @@ void *open_settings_r(const char *sessionname)
     if (!fp)
 	return NULL;		       /* can't open */
 
-    ret = newtree234(keycmp);
+    toret = snew(settings_r);
+    toret->t = newtree234(keycmp);
 
     while ( (line = fgetline(fp)) ) {
         char *value = strchr(line, '=');
@@ -376,25 +386,24 @@ void *open_settings_r(const char *sessionname)
         kv = snew(struct skeyval);
         kv->key = dupstr(line);
         kv->value = dupstr(value);
-        add234(ret, kv);
+        add234(toret->t, kv);
 
         sfree(line);
     }
 
     fclose(fp);
 
-    return ret;
+    return toret;
 }
 
-char *read_setting_s(void *handle, const char *key)
+char *read_setting_s(settings_r *handle, const char *key)
 {
-    tree234 *tree = (tree234 *)handle;
     const char *val;
     struct skeyval tmp, *kv;
 
     tmp.key = key;
-    if (tree != NULL &&
-        (kv = find234(tree, &tmp, NULL)) != NULL) {
+    if (handle != NULL &&
+        (kv = find234(handle->t, &tmp, NULL)) != NULL) {
         val = kv->value;
         assert(val != NULL);
     } else
@@ -406,15 +415,14 @@ char *read_setting_s(void *handle, const char *key)
 	return dupstr(val);
 }
 
-int read_setting_i(void *handle, const char *key, int defvalue)
+int read_setting_i(settings_r *handle, const char *key, int defvalue)
 {
-    tree234 *tree = (tree234 *)handle;
     const char *val;
     struct skeyval tmp, *kv;
 
     tmp.key = key;
-    if (tree != NULL &&
-        (kv = find234(tree, &tmp, NULL)) != NULL) {
+    if (handle != NULL &&
+        (kv = find234(handle->t, &tmp, NULL)) != NULL) {
         val = kv->value;
         assert(val != NULL);
     } else
@@ -426,7 +434,7 @@ int read_setting_i(void *handle, const char *key, int defvalue)
 	return atoi(val);
 }
 
-FontSpec *read_setting_fontspec(void *handle, const char *name)
+FontSpec *read_setting_fontspec(settings_r *handle, const char *name)
 {
     /*
      * In GTK1-only PuTTY, we used to store font names simply as a
@@ -464,7 +472,7 @@ FontSpec *read_setting_fontspec(void *handle, const char *name)
 	return NULL;
     }
 }
-Filename *read_setting_filename(void *handle, const char *name)
+Filename *read_setting_filename(settings_r *handle, const char *name)
 {
     char *tmp = read_setting_s(handle, name);
     if (tmp) {
@@ -475,7 +483,7 @@ Filename *read_setting_filename(void *handle, const char *name)
 	return NULL;
 }
 
-void write_setting_fontspec(void *handle, const char *name, FontSpec *fs)
+void write_setting_fontspec(settings_w *handle, const char *name, FontSpec *fs)
 {
     /*
      * read_setting_fontspec had to handle two cases, but when
@@ -486,27 +494,28 @@ void write_setting_fontspec(void *handle, const char *name, FontSpec *fs)
     write_setting_s(handle, suffname, fs->name);
     sfree(suffname);
 }
-void write_setting_filename(void *handle, const char *name, Filename *result)
+void write_setting_filename(settings_w *handle,
+                            const char *name, Filename *result)
 {
     write_setting_s(handle, name, result->path);
 }
 
-void close_settings_r(void *handle)
+void close_settings_r(settings_r *handle)
 {
-    tree234 *tree = (tree234 *)handle;
     struct skeyval *kv;
 
-    if (!tree)
+    if (!handle)
         return;
 
-    while ( (kv = index234(tree, 0)) != NULL) {
-        del234(tree, kv);
+    while ( (kv = index234(handle->t, 0)) != NULL) {
+        del234(handle->t, kv);
         sfree((char *)kv->key);
         sfree((char *)kv->value);
         sfree(kv);
     }
 
-    freetree234(tree);
+    freetree234(handle->t);
+    sfree(handle);
 }
 
 void del_settings(const char *sessionname)
@@ -517,7 +526,11 @@ void del_settings(const char *sessionname)
     sfree(filename);
 }
 
-void *enum_settings_start(void)
+struct settings_e {
+    DIR *dp;
+};
+
+settings_e *enum_settings_start(void)
 {
     DIR *dp;
     char *filename;
@@ -526,12 +539,13 @@ void *enum_settings_start(void)
     dp = opendir(filename);
     sfree(filename);
 
-    return dp;
+    settings_e *toret = snew(settings_e);
+    toret->dp = dp;
+    return toret;
 }
 
-char *enum_settings_next(void *handle, char *buffer, int buflen)
+char *enum_settings_next(settings_e *handle, char *buffer, int buflen)
 {
-    DIR *dp = (DIR *)handle;
     struct dirent *de;
     struct stat st;
     char *fullpath;
@@ -541,7 +555,7 @@ char *enum_settings_next(void *handle, char *buffer, int buflen)
     fullpath = make_filename(INDEX_SESSIONDIR, NULL);
     maxlen = len = strlen(fullpath);
 
-    while ( (de = readdir(dp)) != NULL ) {
+    while ( (de = readdir(handle->dp)) != NULL ) {
         thislen = len + 1 + strlen(de->d_name);
 	if (maxlen < thislen) {
 	    maxlen = thislen;
@@ -566,10 +580,10 @@ char *enum_settings_next(void *handle, char *buffer, int buflen)
     return NULL;
 }
 
-void enum_settings_finish(void *handle)
+void enum_settings_finish(settings_e *handle)
 {
-    DIR *dp = (DIR *)handle;
-    closedir(dp);
+    closedir(handle->dp);
+    sfree(handle);
 }
 
 /*
diff --git a/windows/winjump.c b/windows/winjump.c
index 7e7b34e8..e42ba275 100644
--- a/windows/winjump.c
+++ b/windows/winjump.c
@@ -383,7 +383,6 @@ static IShellLink *make_shell_link(const char *appname,
 {
     IShellLink *ret;
     char *app_path, *param_string, *desc_string;
-    void *psettings_tmp;
     IPropertyStore *pPS;
     PROPVARIANT pv;
 
@@ -409,7 +408,7 @@ static IShellLink *make_shell_link(const char *appname,
 
     /* Check if this is a valid session, otherwise don't add. */
     if (sessionname) {
-        psettings_tmp = open_settings_r(sessionname);
+        settings_r *psettings_tmp = open_settings_r(sessionname);
         if (!psettings_tmp) {
             sfree(app_path);
             return NULL;
diff --git a/windows/winstore.c b/windows/winstore.c
index 26cbf634..7c4be074 100644
--- a/windows/winstore.c
+++ b/windows/winstore.c
@@ -74,7 +74,11 @@ static void unmungestr(const char *in, char *out, int outlen)
     return;
 }
 
-void *open_settings_w(const char *sessionname, char **errmsg)
+struct settings_w {
+    HKEY sesskey;
+};
+
+settings_w *open_settings_w(const char *sessionname, char **errmsg)
 {
     HKEY subkey1, sesskey;
     int ret;
@@ -104,29 +108,37 @@ void *open_settings_w(const char *sessionname, char **errmsg)
 	return NULL;
     }
     sfree(p);
-    return (void *) sesskey;
+
+    settings_w *toret = snew(settings_w);
+    toret->sesskey = sesskey;
+    return toret;
 }
 
-void write_setting_s(void *handle, const char *key, const char *value)
+void write_setting_s(settings_w *handle, const char *key, const char *value)
 {
     if (handle)
-	RegSetValueEx((HKEY) handle, key, 0, REG_SZ, (CONST BYTE *)value,
+        RegSetValueEx(handle->sesskey, key, 0, REG_SZ, (CONST BYTE *)value,
 		      1 + strlen(value));
 }
 
-void write_setting_i(void *handle, const char *key, int value)
+void write_setting_i(settings_w *handle, const char *key, int value)
 {
     if (handle)
-	RegSetValueEx((HKEY) handle, key, 0, REG_DWORD,
+        RegSetValueEx(handle->sesskey, key, 0, REG_DWORD,
 		      (CONST BYTE *) &value, sizeof(value));
 }
 
-void close_settings_w(void *handle)
+void close_settings_w(settings_w *handle)
 {
-    RegCloseKey((HKEY) handle);
+    RegCloseKey(handle->sesskey);
+    sfree(handle);
 }
 
-void *open_settings_r(const char *sessionname)
+struct settings_r {
+    HKEY sesskey;
+};
+
+settings_r *open_settings_r(const char *sessionname)
 {
     HKEY subkey1, sesskey;
     char *p;
@@ -148,10 +160,12 @@ void *open_settings_r(const char *sessionname)
 
     sfree(p);
 
-    return (void *) sesskey;
+    settings_r *toret = snew(settings_r);
+    toret->sesskey = sesskey;
+    return toret;
 }
 
-char *read_setting_s(void *handle, const char *key)
+char *read_setting_s(settings_r *handle, const char *key)
 {
     DWORD type, allocsize, size;
     char *ret;
@@ -160,14 +174,14 @@ char *read_setting_s(void *handle, const char *key)
 	return NULL;
 
     /* Find out the type and size of the data. */
-    if (RegQueryValueEx((HKEY) handle, key, 0,
+    if (RegQueryValueEx(handle->sesskey, key, 0,
 			&type, NULL, &size) != ERROR_SUCCESS ||
 	type != REG_SZ)
 	return NULL;
 
     allocsize = size+1;         /* allow for an extra NUL if needed */
     ret = snewn(allocsize, char);
-    if (RegQueryValueEx((HKEY) handle, key, 0,
+    if (RegQueryValueEx(handle->sesskey, key, 0,
 			&type, (BYTE *)ret, &size) != ERROR_SUCCESS ||
 	type != REG_SZ) {
         sfree(ret);
@@ -180,13 +194,13 @@ char *read_setting_s(void *handle, const char *key)
     return ret;
 }
 
-int read_setting_i(void *handle, const char *key, int defvalue)
+int read_setting_i(settings_r *handle, const char *key, int defvalue)
 {
     DWORD type, val, size;
     size = sizeof(val);
 
     if (!handle ||
-	RegQueryValueEx((HKEY) handle, key, 0, &type,
+        RegQueryValueEx(handle->sesskey, key, 0, &type,
 			(BYTE *) &val, &size) != ERROR_SUCCESS ||
 	size != sizeof(val) || type != REG_DWORD)
 	return defvalue;
@@ -194,7 +208,7 @@ int read_setting_i(void *handle, const char *key, int defvalue)
 	return val;
 }
 
-FontSpec *read_setting_fontspec(void *handle, const char *name)
+FontSpec *read_setting_fontspec(settings_r *handle, const char *name)
 {
     char *settingname;
     char *fontname;
@@ -234,7 +248,8 @@ FontSpec *read_setting_fontspec(void *handle, const char *name)
     return ret;
 }
 
-void write_setting_fontspec(void *handle, const char *name, FontSpec *font)
+void write_setting_fontspec(settings_w *handle,
+                            const char *name, FontSpec *font)
 {
     char *settingname;
 
@@ -250,7 +265,7 @@ void write_setting_fontspec(void *handle, const char *name, FontSpec *font)
     sfree(settingname);
 }
 
-Filename *read_setting_filename(void *handle, const char *name)
+Filename *read_setting_filename(settings_r *handle, const char *name)
 {
     char *tmp = read_setting_s(handle, name);
     if (tmp) {
@@ -261,14 +276,16 @@ Filename *read_setting_filename(void *handle, const char *name)
 	return NULL;
 }
 
-void write_setting_filename(void *handle, const char *name, Filename *result)
+void write_setting_filename(settings_w *handle,
+                            const char *name, Filename *result)
 {
     write_setting_s(handle, name, result->path);
 }
 
-void close_settings_r(void *handle)
+void close_settings_r(settings_r *handle)
 {
-    RegCloseKey((HKEY) handle);
+    RegCloseKey(handle->sesskey);
+    sfree(handle);
 }
 
 void del_settings(const char *sessionname)
@@ -289,20 +306,20 @@ void del_settings(const char *sessionname)
     remove_session_from_jumplist(sessionname);
 }
 
-struct enumsettings {
+struct settings_e {
     HKEY key;
     int i;
 };
 
-void *enum_settings_start(void)
+settings_e *enum_settings_start(void)
 {
-    struct enumsettings *ret;
+    settings_e *ret;
     HKEY key;
 
     if (RegOpenKey(HKEY_CURRENT_USER, puttystr, &key) != ERROR_SUCCESS)
 	return NULL;
 
-    ret = snew(struct enumsettings);
+    ret = snew(settings_e);
     if (ret) {
 	ret->key = key;
 	ret->i = 0;
@@ -311,9 +328,8 @@ void *enum_settings_start(void)
     return ret;
 }
 
-char *enum_settings_next(void *handle, char *buffer, int buflen)
+char *enum_settings_next(settings_e *e, char *buffer, int buflen)
 {
-    struct enumsettings *e = (struct enumsettings *) handle;
     char *otherbuf;
     otherbuf = snewn(3 * buflen, char);
     if (RegEnumKey(e->key, e->i++, otherbuf, 3 * buflen) == ERROR_SUCCESS) {
@@ -326,9 +342,8 @@ char *enum_settings_next(void *handle, char *buffer, int buflen)
     }
 }
 
-void enum_settings_finish(void *handle)
+void enum_settings_finish(settings_e *e)
 {
-    struct enumsettings *e = (struct enumsettings *) handle;
     RegCloseKey(e->key);
     sfree(e);
 }
@@ -656,7 +671,7 @@ static int transform_jumplist_registry
     (const char *add, const char *rem, char **out)
 {
     int ret;
-    HKEY pjumplist_key, psettings_tmp;
+    HKEY pjumplist_key;
     DWORD type;
     DWORD value_length;
     char *old_value, *new_value;
@@ -741,7 +756,7 @@ static int transform_jumplist_registry
         while (*piterator_old != '\0') {
             if (!rem || strcmp(piterator_old, rem) != 0) {
                 /* Check if this is a valid session, otherwise don't add. */
-                psettings_tmp = open_settings_r(piterator_old);
+                settings_r *psettings_tmp = open_settings_r(piterator_old);
                 if (psettings_tmp != NULL) {
                     close_settings_r(psettings_tmp);
                     strcpy(piterator_new, piterator_old);