kernel: disallow invalid wiping option combination

Instead of failing the chainstate_manager_create call, disallow
setting the set_wipe_block_tree_db and set_wipe_chainstate_db
options to invalid combinations. This improves user error feedback,
removing the need to inspect the logs when creating a
ChainstateManager fails.

src/kernel/bitcoinkernel.cpp

@@ -769,12 +769,18 @@ kernel_ChainstateManagerOptions* kernel_chainstate_manager_options_create(
     }
 }
 
-void kernel_chainstate_manager_options_set_wipe_chainstate_db(
+bool kernel_chainstate_manager_options_set_wipe_chainstate_db(
     kernel_ChainstateManagerOptions* chainstate_manager_opts_,
     bool wipe_chainstate_db)
 {
     auto chainstate_load_opts{cast_chainstate_load_options(chainstate_manager_opts_)};
+    auto block_manager_opts{cast_block_manager_options(chainstate_manager_opts_)};
+    if (block_manager_opts->block_tree_db_params.wipe_data && !wipe_chainstate_db) {
+        LogWarning("Wiping the block tree db without also wiping the chainstate db is currently unsupported.");
+        return false;
+    }
     chainstate_load_opts->wipe_chainstate_db = wipe_chainstate_db;
+    return true;
 }
 
 void kernel_chainstate_manager_options_set_chainstate_db_in_memory(
@@ -798,12 +804,18 @@ void kernel_chainstate_manager_options_destroy(kernel_ChainstateManagerOptions*
     }
 }
 
-void kernel_chainstate_manager_options_set_wipe_block_tree_db(
+bool kernel_chainstate_manager_options_set_wipe_block_tree_db(
     kernel_ChainstateManagerOptions* chainstate_manager_opts_,
     bool wipe_block_tree_db)
 {
     auto block_manager_options{cast_block_manager_options(chainstate_manager_opts_)};
+    auto chainstate_load_opts{cast_chainstate_load_options(chainstate_manager_opts_)};
+    if (wipe_block_tree_db && !chainstate_load_opts->wipe_chainstate_db) {
+        LogWarning("Wiping the block tree db without also wiping the chainstate db is currently unsupported.");
+        return false;
+    }
     block_manager_options->block_tree_db_params.wipe_data = wipe_block_tree_db;
+    return true;
 }
 
 void kernel_chainstate_manager_options_set_block_tree_db_in_memory(

src/kernel/bitcoinkernel.h

@@ -767,11 +767,16 @@ BITCOINKERNEL_API kernel_ChainstateManagerOptions* BITCOINKERNEL_WARN_UNUSED_RES
 
 /**
  * @brief Sets wipe block tree db in the chainstate manager options.
+ *        If wipe_chainstate_db is set to False, this option may not be
+ *        set to True.
  *
  * @param[in] chainstate_manager_options Non-null, options to be set.
  * @param[in] wipe_block_tree_db    Set wipe block tree db.
+ *
+ * @return  True if the set was successful, False if the set failed
+ *          due to wipe_chainstate_db incompatibility.
  */
-BITCOINKERNEL_API void kernel_chainstate_manager_options_set_wipe_block_tree_db(
+BITCOINKERNEL_API bool BITCOINKERNEL_WARN_UNUSED_RESULT kernel_chainstate_manager_options_set_wipe_block_tree_db(
     kernel_ChainstateManagerOptions* chainstate_manager_options,
     bool wipe_block_tree_db) BITCOINKERNEL_ARG_NONNULL(1);
 
@@ -788,11 +793,15 @@ BITCOINKERNEL_API void kernel_chainstate_manager_options_set_block_tree_db_in_me
 
 /**
  * @brief Sets wipe chainstate db in the chainstate manager options.
+ *        If wipe_block_tree_db is set to True, this must be set to True.
  *
  * @param[in] chainstate_manager_options Non-null, options to be set.
  * @param[in] wipe_chainstate_db      Set wipe chainstate db.
+ *
+ * @return  True if the set was successful, False if the set failed
+ *          due to wipe_block_tree_db incompatibility.
  */
-BITCOINKERNEL_API void kernel_chainstate_manager_options_set_wipe_chainstate_db(
+BITCOINKERNEL_API bool BITCOINKERNEL_WARN_UNUSED_RESULT kernel_chainstate_manager_options_set_wipe_chainstate_db(
     kernel_ChainstateManagerOptions* chainstate_manager_options,
     bool wipe_chainstate_db) BITCOINKERNEL_ARG_NONNULL(1);
 

src/kernel/bitcoinkernel_wrapper.h

@@ -401,19 +401,19 @@ class ChainstateManagerOptions
     {
     }
 
-    void SetWipeBlockTreeDb(bool wipe_block_tree) const noexcept
+    bool SetWipeBlockTreeDb(bool wipe_block_tree) const noexcept
     {
-        kernel_chainstate_manager_options_set_wipe_block_tree_db(m_options.get(), wipe_block_tree);
+        return kernel_chainstate_manager_options_set_wipe_block_tree_db(m_options.get(), wipe_block_tree);
     }
 
     void SetBlockTreeDbInMemory(bool block_tree_db_in_memory) const noexcept
     {
         kernel_chainstate_manager_options_set_block_tree_db_in_memory(m_options.get(), block_tree_db_in_memory);
     }
 
-    void SetWipeChainstateDb(bool wipe_chainstate) const noexcept
+    bool SetWipeChainstateDb(bool wipe_chainstate) const noexcept
     {
-        kernel_chainstate_manager_options_set_wipe_chainstate_db(m_options.get(), wipe_chainstate);
+        return kernel_chainstate_manager_options_set_wipe_chainstate_db(m_options.get(), wipe_chainstate);
     }
 
     void SetChainstateDbInMemory(bool chainstate_db_in_memory) const noexcept

src/test/kernel/test_kernel.cpp

@@ -375,6 +375,7 @@ void chainman_test()
 
     ChainstateManagerOptions chainman_opts{context, test_directory.m_directory.string(), (test_directory.m_directory / "blocks").string()};
     assert(chainman_opts);
+    assert(!chainman_opts.SetWipeBlockTreeDb(true)); // Can't set wipe_block_tree_db to true when wipe_chainstate_db is false
     chainman_opts.SetWorkerThreads(4);
 
     ChainMan chainman{context, chainman_opts};
@@ -392,11 +393,11 @@ std::unique_ptr<ChainMan> create_chainman(TestDirectory& test_directory,
     assert(chainman_opts);
 
     if (reindex) {
-        chainman_opts.SetWipeBlockTreeDb(reindex);
-        chainman_opts.SetWipeChainstateDb(reindex);
+        assert(chainman_opts.SetWipeChainstateDb(reindex));
+        assert(chainman_opts.SetWipeBlockTreeDb(reindex));
     }
     if (wipe_chainstate) {
-        chainman_opts.SetWipeChainstateDb(wipe_chainstate);
+        assert(chainman_opts.SetWipeChainstateDb(wipe_chainstate));
     }
     if (block_tree_db_in_memory) {
         chainman_opts.SetBlockTreeDbInMemory(block_tree_db_in_memory);