Fix macOS Sequoia build with GCC 15 and update README

- Update compiler references from gcc-8 to gcc-15 across build system
  (build-mac.sh, darwin.mk, Makefile_custom)
- Use system Rust (rustup) instead of bundled Rust 1.32.0 for librustzcash
  to fix rlib linker incompatibility on macOS Sequoia
- Replace deprecated std::random_shuffle with std::shuffle (net.cpp,
  transaction_builder.cpp, wallet.cpp)
- Fix -std=gnu17 -> -std=gnu++17 for C++ targets (libzcash, libhush)
- Fix nodiscard warning in glibcxx_sanity.cpp
- Replace deprecated OSMemoryBarrier with std::atomic_thread_fence in LevelDB
- Add -Wno-error=deprecated-declarations to CXXFLAGS for third-party headers
- Fix REMAINING_ARGS unbound variable in build.sh
- Add --disable-tests handling to build-mac.sh
- Update README with correct macOS build dependencies and instructions

src/Makefile.am

@@ -594,7 +594,7 @@ libzcash_a_CPPFLAGS = -DMULTICORE -fopenmp -fPIC -DBOOST_SPIRIT_THREADSAFE -DHAV
 #libzcash_a_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 #libzcash_a_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) -DMONTGOMERY_OUTPUT
 
-libzcash_a_CXXFLAGS = $(SAN_CXXFLAGS) $(HARDENED_CXXFLAGS) -fwrapv -fno-strict-aliasing -std=gnu17
+libzcash_a_CXXFLAGS = $(SAN_CXXFLAGS) $(HARDENED_CXXFLAGS) -fwrapv -fno-strict-aliasing -std=gnu++17
 libzcash_a_LDFLAGS = $(SAN_LDFLAGS) $(HARDENED_LDFLAGS)
 libzcash_a_CPPFLAGS += -DMONTGOMERY_OUTPUT
 
@@ -636,7 +636,7 @@ libhush_a_SOURCES = \
 
 libhush_a_CPPFLAGS = -DMULTICORE -fopenmp -fPIC -DBINARY_OUTPUT -DCURVE_ALT_BN128 -DBOOST_SPIRIT_THREADSAFE -DHAVE_BUILD_INFO -D__STDC_FORMAT_MACROS $(HARDENED_CPPFLAGS) -pipe -O1 -g  -Wstack-protector -fstack-protector-all -fPIE -fvisibility=hidden -DSTATIC $(BITCOIN_INCLUDES)
 
-libhush_a_CXXFLAGS = $(HARDENED_CXXFLAGS) -fwrapv -fno-strict-aliasing -std=gnu17
+libhush_a_CXXFLAGS = $(HARDENED_CXXFLAGS) -fwrapv -fno-strict-aliasing -std=gnu++17
 
 libhush_a_LDFLAGS = $(HARDENED_LDFLAGS)
 

src/cc/Makefile_custom

@@ -1,5 +1,5 @@
 SHELL		= /bin/sh
-CC_DARWIN	= g++-8
+CC_DARWIN	= g++-15
 CC_WIN		= x86_64-w64-mingw32-gcc-posix
 CC_AARCH64	= aarch64-linux-gnu-g++
 CFLAGS_DARWIN	= -DBUILD_CUSTOMCC -std=c++11 -arch x86_64 -I../secp256k1/include -I../../depends/$(shell echo `../..//depends/config.guess`/include) -I../univalue/include -I../leveldb/include -I.. -I. -fPIC -Wl,-undefined -Wl,dynamic_lookup -Wno-write-strings -shared -dynamiclib

src/compat/glibcxx_sanity.cpp

@@ -47,7 +47,7 @@ bool sanity_test_range_fmt()
 {
     std::string test;
     try {
-        test.at(1);
+        (void)test.at(1);
     } catch (const std::out_of_range&) {
         return true;
     } catch (...) {

src/leveldb/port/atomic_pointer.h

@@ -51,8 +51,9 @@ namespace port {
 
 // Mac OS
 #elif defined(OS_MACOSX)
+#include <atomic>
 inline void MemoryBarrier() {
-  OSMemoryBarrier();
+  std::atomic_thread_fence(std::memory_order_seq_cst);
 }
 #define LEVELDB_HAVE_MEMORY_BARRIER
 

src/net.cpp

@@ -33,6 +33,8 @@
 #include "crypto/common.h"
 #include "hush/utiltls.h"
 #include <random.h>
+#include <random>
+#include <limits>
 #ifdef _WIN32
 #include <string.h>
 #else
@@ -2004,7 +2006,7 @@ void ThreadMessageHandler()
         // Randomize the order in which we process messages from/to our peers.
         // This prevents attacks in which an attacker exploits having multiple
         // consecutive connections in the vNodes list.
-        random_shuffle(vNodesCopy.begin(), vNodesCopy.end(), GetRandInt);
+        std::shuffle(vNodesCopy.begin(), vNodesCopy.end(), std::mt19937(GetRand(std::numeric_limits<uint32_t>::max())));
 
         BOOST_FOREACH(CNode* pnode, vNodesCopy)
         {
@@ -2516,7 +2518,7 @@ void RelayTransaction(const CTransaction& tx, const CDataStream& ss)
     // We always round down, except when we have only 1 connection
     auto newSize = (vNodes.size() / 2) == 0 ? 1 : (vNodes.size() / 2);
 
-    random_shuffle( vRelayNodes.begin(), vRelayNodes.end(), GetRandInt );
+    std::shuffle( vRelayNodes.begin(), vRelayNodes.end(), std::mt19937(GetRand(std::numeric_limits<uint32_t>::max())) );
 
     vRelayNodes.resize(newSize);
     if (HUSH_TESTNODE==1 && vNodes.size() == 0) {

src/transaction_builder.cpp

@@ -11,6 +11,8 @@
 #include <boost/optional/optional_io.hpp>
 #include <librustzcash.h>
 #include "zcash/Note.hpp"
+#include <random>
+#include <limits>
 extern bool fZDebug;
 
 SpendDescriptionInfo::SpendDescriptionInfo(
@@ -66,7 +68,7 @@ void TransactionBuilder::AddSaplingOutput(
 void TransactionBuilder::ShuffleOutputs()
 {
     LogPrintf("%s: Shuffling %d zouts\n", __func__, outputs.size() );
-    random_shuffle( outputs.begin(), outputs.end(), GetRandInt );
+    std::shuffle( outputs.begin(), outputs.end(), std::mt19937(GetRand(std::numeric_limits<uint32_t>::max())) );
 }
 
 void TransactionBuilder::AddTransparentInput(COutPoint utxo, CScript scriptPubKey, CAmount value, uint32_t _nSequence)

src/wallet/wallet.cpp

@@ -39,6 +39,8 @@
 #include "coins.h"
 #include "wallet/asyncrpcoperation_saplingconsolidation.h"
 #include "wallet/asyncrpcoperation_sweep.h"
+#include <random>
+#include <limits>
 #include "zcash/zip32.h"
 #include "cc/CCinclude.h"
 #include <assert.h>
@@ -3416,7 +3418,7 @@ bool CWallet::SelectCoinsMinConf(const CAmount& nTargetValue, int nConfMine, int
     vector<pair<CAmount, pair<const CWalletTx*,unsigned int> > > vValue;
     CAmount nTotalLower = 0;
 
-    random_shuffle(vCoins.begin(), vCoins.end(), GetRandInt);
+    std::shuffle(vCoins.begin(), vCoins.end(), std::mt19937(GetRand(std::numeric_limits<uint32_t>::max())));
 
     BOOST_FOREACH(const COutput &output, vCoins)
     {