Stop using "config_suite_offset=-1" to indicate "no config suite."

Instead, create a separate "has_config_suite" boolean, so that only
top-level formats with config_suites need to declare an offset at
all.

3 files changed, 15 insertions, 5 deletions

diff --git a/src/lib/conf/conftypes.h b/src/lib/conf/conftypes.h
index d4e2ea218a..dfe51cfba1 100644
--- a/src/lib/conf/conftypes.h
+++ b/src/lib/conf/conftypes.h
@@ -335,8 +335,14 @@ typedef struct config_format_t {
   /** If present, extra denotes a LINELIST variable for unrecognized
    * lines.  Otherwise, unrecognized lines are an error. */
   const struct_member_t *extra;
-  /** The position of a config_suite_t pointer within the toplevel object,
-   * or -1 if there is no such pointer. */
+  /**
+   * If true, this format describes a top-level configuration, with
+   * a suite containing multiple sub-configuration objects.
+   */
+  bool has_config_suite;
+  /** The position of a config_suite_t pointer within the toplevel object.
+   * Ignored unless have_config_suite is true.
+   */
   ptrdiff_t config_suite_offset;
 } config_format_t;
 
diff --git a/src/lib/confmgt/confmgt.c b/src/lib/confmgt/confmgt.c
index 1c1a1595ec..a96c7f96bf 100644
--- a/src/lib/confmgt/confmgt.c
+++ b/src/lib/confmgt/confmgt.c
@@ -169,9 +169,14 @@ config_mgr_register_fmt(config_mgr_t *mgr,
               "it had been frozen.");
 
   if (object_idx != IDX_TOPLEVEL) {
-    tor_assertf(fmt->config_suite_offset < 0,
+    tor_assertf(! fmt->has_config_suite,
           "Tried to register a toplevel format in a non-toplevel position");
   }
+  if (fmt->config_suite_offset) {
+    tor_assertf(fmt->has_config_suite,
+                "config_suite_offset was set, but has_config_suite was not.");
+  }
+
   tor_assertf(fmt != mgr->toplevel &&
               ! smartlist_contains(mgr->subconfigs, fmt),
               "Tried to register an already-registered format.");
@@ -223,7 +228,7 @@ config_mgr_add_format(config_mgr_t *mgr,
 static inline config_suite_t **
 config_mgr_get_suite_ptr(const config_mgr_t *mgr, void *toplevel)
 {
-  if (mgr->toplevel->config_suite_offset < 0)
+  if (! mgr->toplevel->has_config_suite)
     return NULL;
   return STRUCT_VAR_P(toplevel, mgr->toplevel->config_suite_offset);
 }
diff --git a/src/lib/crypt_ops/crypto_init.c b/src/lib/crypt_ops/crypto_init.c
index 4b08456197..fbd4da4704 100644
--- a/src/lib/crypt_ops/crypto_init.c
+++ b/src/lib/crypt_ops/crypto_init.c
@@ -293,7 +293,6 @@ static const config_format_t crypto_options_fmt = {
              offsetof(crypto_options_t, magic) },
   .vars = crypto_options_t_vars,
   .validate_fn = crypto_options_validate,
-  .config_suite_offset = -1,
 };
 
 /**