From 0645d473208c2cb7e62a1f1915f46f95b4b990f7 Mon Sep 17 00:00:00 2001 From: PastaPastaPasta <6443210+PastaPastaPasta@users.noreply.github.com> Date: Wed, 22 Dec 2021 03:59:27 -0600 Subject: [PATCH] Merge #15292: Remove 'boost::optional'-related false positive -Wmaybe-uninitialized warnings on GCC compiler (#4635) 2d483142a7051389afe74c57a216843e6306f1a8 Remove 'boost::optional'-related gcc warnings (Hennadii Stepanov) Pull request description: #14711 introduced some warnings when building with gcc compiler. See: - https://github.com/bitcoin/bitcoin/pull/14711#issuecomment-454760017 by @laanwj - https://github.com/bitcoin/bitcoin/pull/14711#pullrequestreview-193702611 by @ryanofsky This gcc [issue](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47679) has been known since version 4.6.0 and last updated in 2017. From the boost [docs](https://www.boost.org/doc/libs/1_69_0/libs/optional/doc/html/boost_optional/quick_start/optional_automatic_variables.html): > The default constructor of `optional` creates an _uninitialized_ `optional` object. Also: [False positive with -Wmaybe-uninitialized](https://www.boost.org/doc/libs/1_69_0/libs/optional/doc/html/boost_optional/tutorial/gotchas/false_positive_with__wmaybe_uninitialized.html) ([pointed out](https://github.com/bitcoin/bitcoin/pull/15292#issuecomment-459063170) by @Empact) This PR removes these warnings. cc: @Empact @practicalswift Tree-SHA512: 752ae3c3ca6282bbf98726236fbc3069ab9d1aee57ae2ec2668b32e4541e7bc1acb15b7d6fa9e2b6daf1ec29c0987a1053ee1ca0f523b71367ff911221c58c94 Co-authored-by: Wladimir J. van der Laan --- src/optional.h | 9 +++++++++ src/wallet/rpcwallet.cpp | 3 ++- src/wallet/wallet.cpp | 3 ++- 3 files changed, 13 insertions(+), 2 deletions(-) diff --git a/src/optional.h b/src/optional.h index 1614c8971836d..95a3b24d0a027 100644 --- a/src/optional.h +++ b/src/optional.h @@ -5,12 +5,21 @@ #ifndef BITCOIN_OPTIONAL_H #define BITCOIN_OPTIONAL_H +#include + #include //! Substitute for C++17 std::optional template using Optional = boost::optional; +//! Substitute for C++17 std::make_optional +template +Optional MakeOptional(bool condition, T&& value) +{ + return boost::make_optional(condition, std::forward(value)); +} + //! Substitute for C++17 std::nullopt static auto& nullopt = boost::none; diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp index c439418886ea2..c0e40e9b4a4eb 100644 --- a/src/wallet/rpcwallet.cpp +++ b/src/wallet/rpcwallet.cpp @@ -1656,7 +1656,8 @@ static UniValue listsinceblock(const JSONRPCRequest& request) LockAnnotation lock(::cs_main); LOCK(pwallet->cs_wallet); - Optional height; // Height of the specified block or the common ancestor, if the block provided was in a deactivated chain. + // The way the 'height' is initialized is just a workaround for the gcc bug #47679 since version 4.6.0. + Optional height = MakeOptional(false, int()); // Height of the specified block or the common ancestor, if the block provided was in a deactivated chain. Optional altheight; // Height of the specified block, even if it's in a deactivated chain. int target_confirms = 1; isminefilter filter = ISMINE_SPENDABLE; diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp index c7b82cf6e40f2..5c886230e9971 100644 --- a/src/wallet/wallet.cpp +++ b/src/wallet/wallet.cpp @@ -2182,7 +2182,8 @@ CWallet::ScanResult CWallet::ScanForWalletTransactions(const uint256& start_bloc fAbortRescan = false; ShowProgress(strprintf("%s " + _("Rescanning..."), GetDisplayName()), 0); // show rescan progress in GUI as dialog or on splashscreen, if -rescan on startup uint256 tip_hash; - Optional block_height; + // The way the 'block_height' is initialized is just a workaround for the gcc bug #47679 since version 4.6.0. + Optional block_height = MakeOptional(false, int()); double progress_begin; double progress_end; {