From d69a582e72ea6eee67b5f659dd57c75e936a98dc Mon Sep 17 00:00:00 2001
From: TheCharlatan <seb.kung@gmail.com>
Date: Sun, 1 Jun 2025 18:31:40 +0200
Subject: [PATCH 1/2] kernel: Remove some unnecessary non-kernel includes

Specifically gets rid of batchpriority, chainparams, script/sign.h and
system includes.

Also take the opportunity of cleaning up the headers for the effected
files and adding them to the iwyu-enforced set.
---
 ci/test/03_test_script.sh  |  2 +-
 src/core_read.cpp          | 16 +++++++++++++---
 src/node/blockstorage.cpp  | 15 +++++++++++----
 src/node/blockstorage.h    |  5 +++++
 src/node/utxo_snapshot.cpp |  2 +-
 src/node/utxo_snapshot.h   | 10 +++++++---
 src/signet.cpp             | 13 +++++++------
 src/signet.h               |  6 +++++-
 8 files changed, 50 insertions(+), 19 deletions(-)

diff --git a/ci/test/03_test_script.sh b/ci/test/03_test_script.sh
index 39e13945e25..7f8fad71408 100755
--- a/ci/test/03_test_script.sh
+++ b/ci/test/03_test_script.sh
@@ -209,7 +209,7 @@ if [ "${RUN_TIDY}" = "true" ]; then
   fi
 
   # TODO: Consider enforcing IWYU across the entire codebase.
-  FILES_WITH_ENFORCED_IWYU="/src/(crypto|index)/.*\\.cpp"
+  FILES_WITH_ENFORCED_IWYU="/src/((crypto|index)/.*\\.cpp|node/blockstorage.cpp|node/utxo_snapshot.cpp|core_read.cpp|signet.cpp)"
   jq --arg patterns "$FILES_WITH_ENFORCED_IWYU" 'map(select(.file | test($patterns)))' "${BASE_BUILD_DIR}/compile_commands.json" > "${BASE_BUILD_DIR}/compile_commands_iwyu_errors.json"
   jq --arg patterns "$FILES_WITH_ENFORCED_IWYU" 'map(select(.file | test($patterns) | not))' "${BASE_BUILD_DIR}/compile_commands.json" > "${BASE_BUILD_DIR}/compile_commands_iwyu_warnings.json"
 
diff --git a/src/core_read.cpp b/src/core_read.cpp
index 59e011e0661..935f465983d 100644
--- a/src/core_read.cpp
+++ b/src/core_read.cpp
@@ -4,17 +4,27 @@
 
 #include <core_io.h>
 
-#include <primitives/block.h>
+#include <primitives/block.h> // IWYU pragma: keep
 #include <primitives/transaction.h>
+#include <script/interpreter.h>
 #include <script/script.h>
-#include <script/sign.h>
 #include <serialize.h>
 #include <streams.h>
 #include <util/result.h>
 #include <util/strencodings.h>
+#include <util/string.h>
+#include <util/translation.h>
 
 #include <algorithm>
-#include <string>
+#include <compare>
+#include <cstdint>
+#include <exception>
+#include <map>
+#include <optional>
+#include <span>
+#include <stdexcept>
+#include <utility>
+#include <vector>
 
 using util::SplitString;
 
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index 71578843947..b0d54add7c1 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -7,12 +7,10 @@
 #include <arith_uint256.h>
 #include <chain.h>
 #include <consensus/params.h>
-#include <consensus/validation.h>
 #include <dbwrapper.h>
 #include <flatfile.h>
 #include <hash.h>
 #include <kernel/blockmanager_opts.h>
-#include <kernel/chain.h>
 #include <kernel/chainparams.h>
 #include <kernel/messagestartchars.h>
 #include <kernel/notifications_interface.h>
@@ -24,16 +22,17 @@
 #include <random.h>
 #include <serialize.h>
 #include <signet.h>
-#include <span.h>
 #include <streams.h>
 #include <sync.h>
 #include <tinyformat.h>
 #include <uint256.h>
 #include <undo.h>
-#include <util/batchpriority.h>
 #include <util/check.h>
+#include <util/expected.h>
 #include <util/fs.h>
 #include <util/obfuscation.h>
+#include <util/overflow.h>
+#include <util/result.h>
 #include <util/signalinterrupt.h>
 #include <util/strencodings.h>
 #include <util/syserror.h>
@@ -41,9 +40,17 @@
 #include <util/translation.h>
 #include <validation.h>
 
+#include <cerrno>
+#include <compare>
 #include <cstddef>
+#include <cstdio>
+#include <exception>
 #include <map>
 #include <optional>
+#include <ostream>
+#include <span>
+#include <stdexcept>
+#include <system_error>
 #include <unordered_map>
 
 namespace kernel {
diff --git a/src/node/blockstorage.h b/src/node/blockstorage.h
index f6bbfae1420..3fb6cc3e5bf 100644
--- a/src/node/blockstorage.h
+++ b/src/node/blockstorage.h
@@ -14,17 +14,22 @@
 #include <kernel/cs_main.h>
 #include <kernel/messagestartchars.h>
 #include <primitives/block.h>
+#include <serialize.h>
 #include <streams.h>
 #include <sync.h>
 #include <uint256.h>
 #include <util/expected.h>
 #include <util/fs.h>
 #include <util/hasher.h>
+#include <util/obfuscation.h>
 
+#include <algorithm>
 #include <array>
 #include <atomic>
+#include <cstddef>
 #include <cstdint>
 #include <functional>
+#include <iosfwd>
 #include <limits>
 #include <map>
 #include <memory>
diff --git a/src/node/utxo_snapshot.cpp b/src/node/utxo_snapshot.cpp
index c2048377f2f..f11e979a357 100644
--- a/src/node/utxo_snapshot.cpp
+++ b/src/node/utxo_snapshot.cpp
@@ -8,7 +8,6 @@
 #include <streams.h>
 #include <sync.h>
 #include <tinyformat.h>
-#include <txdb.h>
 #include <uint256.h>
 #include <util/fs.h>
 #include <validation.h>
@@ -16,6 +15,7 @@
 #include <cassert>
 #include <cstdio>
 #include <optional>
+#include <span>
 #include <string>
 
 namespace node {
diff --git a/src/node/utxo_snapshot.h b/src/node/utxo_snapshot.h
index 7d470246b63..d8b3ca616c8 100644
--- a/src/node/utxo_snapshot.h
+++ b/src/node/utxo_snapshot.h
@@ -6,18 +6,22 @@
 #ifndef BITCOIN_NODE_UTXO_SNAPSHOT_H
 #define BITCOIN_NODE_UTXO_SNAPSHOT_H
 
-#include <chainparams.h>
 #include <kernel/chainparams.h>
 #include <kernel/cs_main.h>
-#include <serialize.h>
+#include <kernel/messagestartchars.h>
 #include <sync.h>
+#include <tinyformat.h>
 #include <uint256.h>
 #include <util/chaintype.h>
-#include <util/check.h>
 #include <util/fs.h>
 
+#include <algorithm>
+#include <array>
 #include <cstdint>
+#include <ios>
 #include <optional>
+#include <set>
+#include <string>
 #include <string_view>
 
 // UTXO set snapshot magic bytes
diff --git a/src/signet.cpp b/src/signet.cpp
index 6524ebff45e..787f5ae42ee 100644
--- a/src/signet.cpp
+++ b/src/signet.cpp
@@ -4,24 +4,25 @@
 
 #include <signet.h>
 
-#include <common/system.h>
 #include <consensus/merkle.h>
 #include <consensus/params.h>
 #include <consensus/validation.h>
-#include <core_io.h>
-#include <hash.h>
 #include <logging.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 #include <script/interpreter.h>
-#include <span.h>
+#include <script/script.h>
 #include <streams.h>
 #include <uint256.h>
-#include <util/strencodings.h>
+#include <util/check.h>
 
 #include <algorithm>
-#include <array>
+#include <cstddef>
 #include <cstdint>
+#include <exception>
+#include <memory>
+#include <span>
+#include <utility>
 #include <vector>
 
 static constexpr uint8_t SIGNET_HEADER[4] = {0xec, 0xc7, 0xda, 0xa2};
diff --git a/src/signet.h b/src/signet.h
index fa347bdef43..9ebae840838 100644
--- a/src/signet.h
+++ b/src/signet.h
@@ -5,12 +5,16 @@
 #ifndef BITCOIN_SIGNET_H
 #define BITCOIN_SIGNET_H
 
-#include <consensus/params.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
 
 #include <optional>
 
+class CScript;
+namespace Consensus {
+struct Params;
+} // namespace Consensus
+
 /**
  * Extract signature and check whether a block has a valid solution
  */

From d3a479cb077d9a9a4451dc4ecb43fe0daf94f172 Mon Sep 17 00:00:00 2001
From: TheCharlatan <seb.kung@gmail.com>
Date: Sun, 1 Jun 2025 19:39:12 +0200
Subject: [PATCH 2/2] kernel: Move BlockInfo to a kernel file

This should avoid having to include interfaces/chain.h from a kernel
module. interfaces/chain.h in turn includes a bunch of non-kernel
headers, that break the desired library topology and might introduce
entanglement regressions.
---
 ci/test/03_test_script.sh |  2 +-
 src/index/base.cpp        |  1 -
 src/interfaces/chain.h    | 17 +----------------
 src/kernel/chain.cpp      |  5 +++--
 src/kernel/chain.h        | 23 +++++++++++++++++++++--
 5 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/ci/test/03_test_script.sh b/ci/test/03_test_script.sh
index 7f8fad71408..d29de80c3e4 100755
--- a/ci/test/03_test_script.sh
+++ b/ci/test/03_test_script.sh
@@ -209,7 +209,7 @@ if [ "${RUN_TIDY}" = "true" ]; then
   fi
 
   # TODO: Consider enforcing IWYU across the entire codebase.
-  FILES_WITH_ENFORCED_IWYU="/src/((crypto|index)/.*\\.cpp|node/blockstorage.cpp|node/utxo_snapshot.cpp|core_read.cpp|signet.cpp)"
+  FILES_WITH_ENFORCED_IWYU="/src/((crypto|index)/.*\\.cpp|node/blockstorage.cpp|node/utxo_snapshot.cpp|core_read.cpp|signet.cpp|kernel/chain.cpp)"
   jq --arg patterns "$FILES_WITH_ENFORCED_IWYU" 'map(select(.file | test($patterns)))' "${BASE_BUILD_DIR}/compile_commands.json" > "${BASE_BUILD_DIR}/compile_commands_iwyu_errors.json"
   jq --arg patterns "$FILES_WITH_ENFORCED_IWYU" 'map(select(.file | test($patterns) | not))' "${BASE_BUILD_DIR}/compile_commands.json" > "${BASE_BUILD_DIR}/compile_commands_iwyu_warnings.json"
 
diff --git a/src/index/base.cpp b/src/index/base.cpp
index 425f9f7eb18..7f77d13a574 100644
--- a/src/index/base.cpp
+++ b/src/index/base.cpp
@@ -9,7 +9,6 @@
 #include <dbwrapper.h>
 #include <interfaces/chain.h>
 #include <interfaces/types.h>
-#include <kernel/chain.h>
 #include <kernel/types.h>
 #include <logging.h>
 #include <node/abort.h>
diff --git a/src/interfaces/chain.h b/src/interfaces/chain.h
index 686da67bfd2..e6847b9b161 100644
--- a/src/interfaces/chain.h
+++ b/src/interfaces/chain.h
@@ -7,6 +7,7 @@
 
 #include <blockfilter.h>
 #include <common/settings.h>
+#include <kernel/chain.h> // IWYU pragma: export
 #include <node/types.h>
 #include <primitives/transaction.h>
 #include <util/result.h>
@@ -78,22 +79,6 @@ public:
     mutable bool found = false;
 };
 
-//! Block data sent with blockConnected, blockDisconnected notifications.
-struct BlockInfo {
-    const uint256& hash;
-    const uint256* prev_hash = nullptr;
-    int height = -1;
-    int file_number = -1;
-    unsigned data_pos = 0;
-    const CBlock* data = nullptr;
-    const CBlockUndo* undo_data = nullptr;
-    // The maximum time in the chain up to and including this block.
-    // A timestamp that can only move forward.
-    unsigned int chain_time_max{0};
-
-    BlockInfo(const uint256& hash LIFETIMEBOUND) : hash(hash) {}
-};
-
 //! The action to be taken after updating a settings value.
 //! WRITE indicates that the updated value must be written to disk,
 //! while SKIP_WRITE indicates that the change will be kept in memory-only
diff --git a/src/kernel/chain.cpp b/src/kernel/chain.cpp
index da515a05f36..0a33e9a1f71 100644
--- a/src/kernel/chain.cpp
+++ b/src/kernel/chain.cpp
@@ -2,9 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <chain.h>
-#include <interfaces/chain.h>
 #include <kernel/chain.h>
+
+#include <chain.h>
+#include <kernel/cs_main.h>
 #include <kernel/types.h>
 #include <sync.h>
 #include <uint256.h>
diff --git a/src/kernel/chain.h b/src/kernel/chain.h
index 9675bb0f547..5afa51f4dda 100644
--- a/src/kernel/chain.h
+++ b/src/kernel/chain.h
@@ -5,12 +5,31 @@
 #ifndef BITCOIN_KERNEL_CHAIN_H
 #define BITCOIN_KERNEL_CHAIN_H
 
-#include<iostream>
+#include <attributes.h>
+
+#include <iostream>
 
 class CBlock;
 class CBlockIndex;
+class CBlockUndo;
+class uint256;
+
 namespace interfaces {
-struct BlockInfo;
+//! Block data sent with blockConnected, blockDisconnected notifications.
+struct BlockInfo {
+    const uint256& hash;
+    const uint256* prev_hash = nullptr;
+    int height = -1;
+    int file_number = -1;
+    unsigned data_pos = 0;
+    const CBlock* data = nullptr;
+    const CBlockUndo* undo_data = nullptr;
+    // The maximum time in the chain up to and including this block.
+    // A timestamp that can only move forward.
+    unsigned int chain_time_max{0};
+
+    BlockInfo(const uint256& hash LIFETIMEBOUND) : hash(hash) {}
+};
 } // namespace interfaces
 
 namespace kernel {