Add option to enable -Wextra for gcc/clang.

.travis.yml

@@ -7,7 +7,7 @@ services:
 env:
   global:
     - DOCKER_IMAGE="mellery451/rippled-ci-builder:2019-08-26"
-    - CMAKE_EXTRA_ARGS="-Dwerr=ON"
+    - CMAKE_EXTRA_ARGS="-Dwerr=ON -Dwextra=ON"
     - NINJA_BUILD=true
     # change this if we get more VM capacity
     - MAX_TIME_MIN=80

Builds/CMake/RippledCompiler.cmake

@@ -87,6 +87,9 @@ if (MSVC)
 else ()
   # HACK : because these need to come first, before any warning demotion
   string (APPEND CMAKE_CXX_FLAGS " -Wall -Wdeprecated")
+  if (wextra)
+    string (APPEND CMAKE_CXX_FLAGS " -Wextra -Wno-unused-parameter")
+  endif ()
   # not MSVC
   target_compile_options (common
     INTERFACE

Builds/CMake/RippledSettings.cmake

@@ -16,9 +16,11 @@ if (is_gcc OR is_clang)
     "Include only src/ripple files when generating coverage report. \
     Set to OFF to include all sources in coverage report."
     ON)
+  option (wextra "compile with extra gcc/clang warnings enabled" ON)
 else ()
   set (profile OFF CACHE BOOL "gcc/clang only" FORCE)
   set (coverage OFF CACHE BOOL "gcc/clang only" FORCE)
+  set (wextra OFF CACHE BOOL "gcc/clang only" FORCE)
 endif ()
 if (is_linux)
   option (BUILD_SHARED_LIBS "build shared ripple libraries" OFF)

src/ripple/app/ledger/Ledger.cpp

@@ -433,9 +433,7 @@ Ledger::read (Keylet const& k) const
             item->size()}, item->key());
     if (! k.check(*sle))
         return nullptr;
-    // need move otherwise makes a copy
+    return sle;
-    // because return type is different
-    return std::move(sle);
 }
 
 //------------------------------------------------------------------------------

src/ripple/app/main/Application.cpp

@@ -1567,7 +1567,7 @@ bool ApplicationImp::setup()
         Resource::Charge loadType = Resource::feeReferenceRPC;
         Resource::Consumer c;
         RPC::Context context { journal ("RPCHandler"), jvCommand, *this,
-            loadType, getOPs (), getLedgerMaster(), c, Role::ADMIN };
+            loadType, getOPs (), getLedgerMaster (), c, Role::ADMIN};
 
         Json::Value jvResult;
         RPC::doCommand (context, jvResult);

src/ripple/app/misc/impl/Manifest.cpp

@@ -146,7 +146,7 @@ boost::optional<Manifest> deserializeManifest(Slice s)
             m.signingKey = PublicKey(makeSlice(spk));
         }
 
-        return std::move(m);
+        return m;
     }
     catch (std::exception const&)
     {

src/ripple/app/misc/impl/Transaction.cpp

@@ -24,6 +24,7 @@
 #include <ripple/app/ledger/LedgerMaster.h>
 #include <ripple/app/main/Application.h>
 #include <ripple/app/misc/HashRouter.h>
+#include <ripple/basics/safe_cast.h>
 #include <ripple/protocol/Feature.h>
 #include <ripple/protocol/jss.h>
 #include <boost/optional.hpp>
@@ -63,7 +64,7 @@ void Transaction::setStatus (TransStatus ts, std::uint32_t lseq)
 TransStatus Transaction::sqlTransactionStatus(
     boost::optional<std::string> const& status)
 {
-    char const c = (status) ? (*status)[0] : txnSqlUnknown;
+    char const c = (status) ? (*status)[0] : safe_cast<char>(txnSqlUnknown);
 
     switch (c)
     {

src/ripple/beast/rfc2616.h

@@ -112,7 +112,11 @@ inline
 bool
 is_char(char c)
 {
+#ifdef __CHAR_UNSIGNED__  /* -funsigned-char */
     return c >= 0 && c <= 127;
+#else
+    return c >= 0;
+#endif
 }
 
 template <class FwdIter>

src/ripple/overlay/PeerReservationTable.h

@@ -44,7 +44,7 @@ struct PeerReservation final
 {
 public:
     PublicKey nodeId;
-    std::string description;
+    std::string description {};
 
     auto
     toJson() const -> Json::Value;

src/ripple/protocol/impl/STParsedJSON.cpp

@@ -819,7 +819,7 @@ static boost::optional <STObject> parseObject (
         // Some inner object types have templates.  Attempt to apply that.
         data.applyTemplateFromSField (inName);  // May throw
 
-        return std::move (data);
+        return data;
     }
     catch (STObject::FieldErr const&)
     {

src/ripple/rpc/Context.h

@@ -55,9 +55,9 @@ struct Context
     LedgerMaster& ledgerMaster;
     Resource::Consumer& consumer;
     Role role;
-    std::shared_ptr<JobQueue::Coro> coro;
+    std::shared_ptr<JobQueue::Coro> coro {};
-    InfoSub::pointer infoSub;
+    InfoSub::pointer infoSub {};
-    Headers headers;
+    Headers headers {};
 };
 
 } // RPC

src/ripple/rpc/impl/TransactionSign.cpp

@@ -353,7 +353,7 @@ transactionPreProcessImpl (
     Json::Value jvResult;
     auto const [pk, sk] = keypairForSignature (params, jvResult);
     if (contains_error (jvResult))
-        return std::move (jvResult);
+        return jvResult;
 
     bool const verify = !(params.isMember (jss::offline)
                           && params[jss::offline].asBool());
@@ -402,7 +402,7 @@ transactionPreProcessImpl (
             ledger);
 
         if (RPC::contains_error (err))
-            return std::move (err);
+            return err;
 
         err = checkPayment (
             params,
@@ -414,7 +414,7 @@ transactionPreProcessImpl (
             verify && signingArgs.editFields());
 
         if (RPC::contains_error(err))
-            return std::move (err);
+            return err;
     }
 
     if (signingArgs.editFields())
@@ -495,7 +495,7 @@ transactionPreProcessImpl (
         err [jss::error] = parsed.error [jss::error];
         err [jss::error_code] = parsed.error [jss::error_code];
         err [jss::error_message] = parsed.error [jss::error_message];
-        return std::move (err);
+        return err;
     }
 
     std::shared_ptr<STTx> stpTrans;

src/ripple/shamap/impl/SHAMapTreeNode.cpp

@@ -46,7 +46,7 @@ SHAMapInnerNode::clone(std::uint32_t seq) const
     std::lock_guard lock(childLock);
     for (int i = 0; i < 16; ++i)
         p->mChildren[i] = mChildren[i];
-    return std::move(p);
+    return p;
 }
 
 std::shared_ptr<SHAMapAbstractNode>

src/test/app/LedgerLoad_test.cpp

@@ -48,9 +48,9 @@ class LedgerLoad_test : public beast::unit_test::suite
     struct SetupData
     {
         std::string const dbPath;
-        std::string ledgerFile;
+        std::string ledgerFile {};
-        Json::Value ledger;
+        Json::Value ledger {};
-        Json::Value hashes;
+        Json::Value hashes {};
     };
 
     SetupData

src/test/app/Path_test.cpp

@@ -220,8 +220,8 @@ public:
         auto& app = env.app();
         Resource::Charge loadType = Resource::feeReferenceRPC;
         Resource::Consumer c;
-        RPC::Context context {env.journal, {}, app, loadType,
+        RPC::Context context { env.journal, {}, app, loadType,
-            app.getOPs(), app.getLedgerMaster(), c, Role::USER, {}};
+            app.getOPs(), app.getLedgerMaster(), c, Role::USER};
 
         Json::Value params = Json::objectValue;
         params[jss::command] = "ripple_path_find";
@@ -320,7 +320,7 @@ public:
         Resource::Charge loadType = Resource::feeReferenceRPC;
         Resource::Consumer c;
         RPC::Context context {env.journal, {}, app, loadType,
-            app.getOPs(), app.getLedgerMaster(), c, Role::USER, {}};
+            app.getOPs(), app.getLedgerMaster(), c, Role::USER};
         Json::Value result;
         gate g;
         // Test RPC::Tuning::max_src_cur source currencies.