Simple tests for nested configuration formats

One test makes sure that the toplevel magic numbers are distinct.

One test makes sure that we can parse a configuration object
with two sub-objects.

src/app/config/confparse.c

@@ -234,7 +234,7 @@ config_mgr_get_suite_ptr(const config_mgr_t *mgr, void *toplevel)
  * to configuration objects for other modules.  This function gets
  * the sub-object for a particular modules.
  */
-static void *
+STATIC void *
 config_mgr_get_obj_mutable(const config_mgr_t *mgr, void *toplevel, int idx)
 {
   tor_assert(mgr);
@@ -253,7 +253,7 @@ config_mgr_get_obj_mutable(const config_mgr_t *mgr, void *toplevel, int idx)
 }
 
 /** As config_mgr_get_obj_mutable(), but return a const pointer. */
-static const void *
+STATIC const void *
 config_mgr_get_obj(const config_mgr_t *mgr, const void *toplevel, int idx)
 {
   return config_mgr_get_obj_mutable(mgr, (void*)toplevel, idx);

src/app/config/confparse.h

@@ -146,6 +146,10 @@ bool config_var_is_contained(const config_var_t *var);
 #ifdef CONFPARSE_PRIVATE
 STATIC void config_reset_line(const config_mgr_t *mgr, void *options,
                               const char *key, int use_defaults);
+STATIC void *config_mgr_get_obj_mutable(const config_mgr_t *mgr,
+                                        void *toplevel, int idx);
+STATIC const void *config_mgr_get_obj(const config_mgr_t *mgr,
+                                       const void *toplevel, int idx);
 #endif
 
 #endif /* !defined(TOR_CONFPARSE_H) */

src/test/test_confmgr.c

@@ -8,6 +8,7 @@
  * formats and configuration objects.
  */
 
+#define CONFPARSE_PRIVATE
 #include "orconfig.h"
 
 #include "core/or/or.h"
@@ -128,12 +129,15 @@ static const config_format_t alpaca_fmt = {
   .deprecations = alpaca_deprecations,
 };
 
+#define LLAMA_IDX 0
+#define ALPACA_IDX 1
+
 static config_mgr_t *
 get_mgr(bool freeze)
 {
   config_mgr_t *mgr = config_mgr_new(&pasture_fmt);
-  tt_int_op(0, OP_EQ, config_mgr_add_format(mgr, &llama_fmt));
-  tt_int_op(1, OP_EQ, config_mgr_add_format(mgr, &alpaca_fmt));
+  tt_int_op(LLAMA_IDX, OP_EQ, config_mgr_add_format(mgr, &llama_fmt));
+  tt_int_op(ALPACA_IDX, OP_EQ, config_mgr_add_format(mgr, &alpaca_fmt));
   if (freeze)
     config_mgr_freeze(mgr);
   return mgr;
@@ -173,10 +177,92 @@ test_confmgr_init(void *arg)
   config_mgr_free(mgr);
 }
 
+static void
+test_confmgr_magic(void *args)
+{
+  (void)args;
+  // Every time we build a manager, it is supposed to get a different magic
+  // number.  Let's test that.
+  config_mgr_t *mgr1 = get_mgr(true);
+  config_mgr_t *mgr2 = get_mgr(true);
+  config_mgr_t *mgr3 = get_mgr(true);
+
+  pasture_cfg_t *p1 = NULL, *p2 = NULL, *p3 = NULL;
+
+  tt_assert(mgr1);
+  tt_assert(mgr2);
+  tt_assert(mgr3);
+
+  p1 = config_new(mgr1);
+  p2 = config_new(mgr2);
+  p3 = config_new(mgr3);
+
+  tt_assert(p1);
+  tt_assert(p2);
+  tt_assert(p3);
+
+  // By chance, two managers get the same magic with P=2^-32.  Let's
+  // make sure that at least two of them are different, so that our
+  // odds of a false positive are 1/2^-64.
+  tt_assert((p1->magic != p2->magic) || (p2->magic != p3->magic));
+
+ done:
+  config_free(mgr1, p1);
+  config_free(mgr2, p2);
+  config_free(mgr3, p3);
+
+  config_mgr_free(mgr1);
+  config_mgr_free(mgr2);
+  config_mgr_free(mgr3);
+}
+
+static const char *simple_pasture =
+  "LLamaname hugo\n"
+  "Alpacaname daphne\n"
+  "gentillesse 42\n"
+  "address 123 Camelid ave\n";
+
+static void
+test_confmgr_parse(void *arg)
+{
+  (void)arg;
+  config_mgr_t *mgr = get_mgr(true);
+  pasture_cfg_t *p = config_new(mgr);
+  config_line_t *lines = NULL;
+  char *msg = NULL;
+
+  config_init(mgr, p); // set defaults.
+
+  int r = config_get_lines(simple_pasture, &lines, 0);
+  tt_int_op(r, OP_EQ, 0);
+  r = config_assign(mgr, p, lines, 0, &msg);
+  tt_int_op(r, OP_EQ, 0);
+
+  tt_int_op(p->opentopublic, OP_EQ, 1);
+  tt_str_op(p->address, OP_EQ, "123 Camelid ave");
+
+  // We are using this API directly; modules outside confparse will, in the
+  // future, not.
+  const alpaca_cfg_t *ac = config_mgr_get_obj(mgr, p, ALPACA_IDX);
+  const llama_cfg_t *lc = config_mgr_get_obj(mgr, p, LLAMA_IDX);
+  tt_str_op(lc->llamaname, OP_EQ, "hugo");
+  tt_str_op(ac->alpacaname, OP_EQ, "daphne");
+  tt_int_op(lc->cuteness, OP_EQ, 42);
+  tt_int_op(ac->fuzziness, OP_EQ, 50);
+
+ done:
+  config_free_lines(lines);
+  config_free(mgr, p);
+  config_mgr_free(mgr);
+  tor_free(msg);
+}
+
 #define CONFMGR_TEST(name, flags)                       \
   { #name, test_confmgr_ ## name, flags, NULL, NULL }
 
 struct testcase_t confmgr_tests[] = {
   CONFMGR_TEST(init, 0),
+  CONFMGR_TEST(magic, 0),
+  CONFMGR_TEST(parse, 0),
   END_OF_TESTCASES
 };