Merge bitcoin/bitcoin#28348: build: Bump g++ minimum supported version to 10

fa5423b5b582aaf8c5b7c516806157244cf20c74 refactor: Remove unused gcc-9 workaround in txrequest (MarcoFalke)
fa918d397dd97114a00ca3d6297f1bb293a8de08 Always enable -Wsuggest-override (MarcoFalke)
faea58eee412d36a020aecf5568e4e3e1f0c5b22 Bump g++ minimum supported version to 10 (MarcoFalke)

Pull request description:

  All supported operating systems ship with g++ 10 (or later), so bumping the minimum should not cause any issues. The bump allows to drop some now-unused workarounds.

  For reference:
  * https://packages.debian.org/bullseye/g++ (`g++-10`)
  * https://packages.ubuntu.com/focal/g++-10
  * FreeBSD 12/13 ships with g++ 12
  * CentOS-like 9 ships with g++ 11
  * OpenSuse Tumbleweed ships with g++ 13 https://software.opensuse.org/package/gcc13-c++ (No idea about OpenSuse Leap)

  This is for Bitcoin Core 27.0 in 2024 (next year), not the soon upcoming 26.0 next month.

ACKs for top commit:
  fanquake:
    ACK fa5423b5b582aaf8c5b7c516806157244cf20c74

Tree-SHA512: 6f0697ae4c0f578873591b7872bf158aba3af17f171c3556b593a70ec379bf94c7a9dd7697e8e79173edd4ac3c81a376e0cbbc0cfabde1a1cfe5f9b5eaea6831

5 files changed, 11 insertions, 21 deletions

diff --git a/ci/test/00_setup_env_native_qt5.sh b/ci/test/00_setup_env_native_qt5.sh
index 32c8557eeb..f351298f1e 100755
--- a/ci/test/00_setup_env_native_qt5.sh
+++ b/ci/test/00_setup_env_native_qt5.sh
@@ -8,14 +8,13 @@ export LC_ALL=C.UTF-8
 
 export CONTAINER_NAME=ci_native_qt5
 export CI_IMAGE_NAME_TAG="docker.io/debian:bullseye"
-# Use minimum supported python3.9 and gcc-9, see doc/dependencies.md
-export PACKAGES="gcc-9 g++-9 python3-zmq qtbase5-dev qttools5-dev-tools libdbus-1-dev libharfbuzz-dev"
-export DEP_OPTS="NO_QT=1 NO_UPNP=1 NO_NATPMP=1 DEBUG=1 ALLOW_HOST_PACKAGES=1 CC=gcc-9 CXX=g++-9"
+# Use minimum supported python3.9 and gcc-10, see doc/dependencies.md
+export PACKAGES="gcc-10 g++-10 python3-zmq qtbase5-dev qttools5-dev-tools libdbus-1-dev libharfbuzz-dev"
+export DEP_OPTS="NO_QT=1 NO_UPNP=1 NO_NATPMP=1 DEBUG=1 ALLOW_HOST_PACKAGES=1 CC=gcc-10 CXX=g++-10"
 export TEST_RUNNER_EXTRA="--previous-releases --coverage --extended --exclude feature_dbcrash"  # Run extended tests so that coverage does not fail, but exclude the very slow dbcrash
 export RUN_UNIT_TESTS_SEQUENTIAL="true"
 export RUN_UNIT_TESTS="false"
 export GOAL="install"
-export NO_WERROR=1  # -Werror=maybe-uninitialized
 export DOWNLOAD_PREVIOUS_RELEASES="true"
 export BITCOIN_CONFIG="--enable-zmq --with-libs=no --with-gui=qt5 --enable-reduce-exports --enable-debug \
 CFLAGS=\"-g0 -O2 -funsigned-char\" CPPFLAGS='-DBOOST_MULTI_INDEX_ENABLE_SAFE_MODE' CXXFLAGS=\"-g0 -O2 -funsigned-char\""
diff --git a/configure.ac b/configure.ac
index d6a9a1161c..6dfd2abfb2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -447,10 +447,7 @@ if test "$CXXFLAGS_overridden" = "no"; then
   AX_CHECK_COMPILE_FLAG([-Wduplicated-cond], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wduplicated-cond"], [], [$CXXFLAG_WERROR])
   AX_CHECK_COMPILE_FLAG([-Wlogical-op], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wlogical-op"], [], [$CXXFLAG_WERROR])
   AX_CHECK_COMPILE_FLAG([-Woverloaded-virtual], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Woverloaded-virtual"], [], [$CXXFLAG_WERROR])
-  dnl -Wsuggest-override is broken with GCC before 9.2
-  dnl https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78010
-  AX_CHECK_COMPILE_FLAG([-Wsuggest-override], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wsuggest-override"], [], [$CXXFLAG_WERROR],
-                        [AC_LANG_SOURCE([[struct A { virtual void f(); }; struct B : A { void f() final; };]])])
+  AX_CHECK_COMPILE_FLAG([-Wsuggest-override], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wsuggest-override"], [], [$CXXFLAG_WERROR])
   AX_CHECK_COMPILE_FLAG([-Wunreachable-code-loop-increment], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wunreachable-code-loop-increment"], [], [$CXXFLAG_WERROR])
   AX_CHECK_COMPILE_FLAG([-Wimplicit-fallthrough], [WARN_CXXFLAGS="$WARN_CXXFLAGS -Wimplicit-fallthrough"], [], [$CXXFLAG_WERROR])
 
diff --git a/doc/dependencies.md b/doc/dependencies.md
index a9a32fe8bd..9d9380bf79 100644
--- a/doc/dependencies.md
+++ b/doc/dependencies.md
@@ -9,7 +9,7 @@ You can find installation instructions in the `build-*.md` file for your platfor
 | [Autoconf](https://www.gnu.org/software/autoconf/) | [2.69](https://github.com/bitcoin/bitcoin/pull/17769) |
 | [Automake](https://www.gnu.org/software/automake/) | [1.13](https://github.com/bitcoin/bitcoin/pull/18290) |
 | [Clang](https://clang.llvm.org) | [13.0](https://github.com/bitcoin/bitcoin/pull/28210) |
-| [GCC](https://gcc.gnu.org) | [9.1](https://github.com/bitcoin/bitcoin/pull/27662) |
+| [GCC](https://gcc.gnu.org) | [10.1](https://github.com/bitcoin/bitcoin/pull/28348) |
 | [Python](https://www.python.org) (scripts, tests) | [3.9](https://github.com/bitcoin/bitcoin/pull/28211) |
 | [systemtap](https://sourceware.org/systemtap/) ([tracing](tracing.md))| N/A |
 
diff --git a/src/txrequest.cpp b/src/txrequest.cpp
index 4c94d4562d..b9a41f26ff 100644
--- a/src/txrequest.cpp
+++ b/src/txrequest.cpp
@@ -72,16 +72,10 @@ struct Announcement {
     /** Whether this is a wtxid request. */
     const bool m_is_wtxid : 1;
 
-    /** What state this announcement is in.
-     *  This is a uint8_t instead of a State to silence a GCC warning in versions prior to 9.3.
-     *  See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61414 */
-    uint8_t m_state : 3;
-
-    /** Convert m_state to a State enum. */
-    State GetState() const { return static_cast<State>(m_state); }
-
-    /** Convert a State enum to a uint8_t and store it in m_state. */
-    void SetState(State state) { m_state = static_cast<uint8_t>(state); }
+    /** What state this announcement is in. */
+    State m_state : 3;
+    State GetState() const { return m_state; }
+    void SetState(State state) { m_state = state; }
 
     /** Whether this announcement is selected. There can be at most 1 selected peer per txhash. */
     bool IsSelected() const
@@ -105,7 +99,7 @@ struct Announcement {
     Announcement(const GenTxid& gtxid, NodeId peer, bool preferred, std::chrono::microseconds reqtime,
         SequenceNumber sequence) :
         m_txhash(gtxid.GetHash()), m_time(reqtime), m_peer(peer), m_sequence(sequence), m_preferred(preferred),
-        m_is_wtxid(gtxid.IsWtxid()), m_state(static_cast<uint8_t>(State::CANDIDATE_DELAYED)) {}
+        m_is_wtxid{gtxid.IsWtxid()}, m_state{State::CANDIDATE_DELAYED} {}
 };
 
 //! Type alias for priorities.
diff --git a/src/util/hasher.h b/src/util/hasher.h
index 506ae9415d..3ad6d5bb94 100644
--- a/src/util/hasher.h
+++ b/src/util/hasher.h
@@ -45,7 +45,7 @@ public:
      * a slight performance penalty (around 1.6%), but this is compensated by
      * memory savings of about 9% which allow for a larger dbcache setting.
      *
-     * @see https://gcc.gnu.org/onlinedocs/gcc-9.2.0/libstdc++/manual/manual/unordered_associative.html
+     * @see https://gcc.gnu.org/onlinedocs/gcc-13.2.0/libstdc++/manual/manual/unordered_associative.html
      */
     size_t operator()(const COutPoint& id) const noexcept {
         return SipHashUint256Extra(k0, k1, id.hash, id.n);