Twiddle the set of warnings that we test against in super-test.sh.

I've added -Wextra as well as removed some of the -Wno-* flags and fixed issues in the code.

Also fixed the cmake build to put user-defined flags after default flags so that they can be overridden.

c++/CMakeLists.txt

@@ -7,7 +7,7 @@ include(CheckIncludeFileCXX)
 if(MSVC)
   check_include_file_cxx(initializer_list HAS_CXX11)
 else()
-  check_include_file_cxx(initializer_list HAS_CXX11 "-std=c++11")
+  check_include_file_cxx(initializer_list HAS_CXX11 "-std=gnu++0x")
 endif()
 if(NOT HAS_CXX11)
   message(SEND_ERROR "Requires a C++11 compiler and standard library.")
@@ -61,9 +61,24 @@ else()
 endif()
 
 if(MSVC)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /W3 ${CAPNP_LITE_FLAG}")
+  # TODO(cleanup): Enable higher warning level in MSVC, but make sure to test
+  #   build with that warning level and clean out false positives.
+  set(CMAKE_CXX_FLAGS "${CAPNP_LITE_FLAG} ${CMAKE_CXX_FLAGS}")
 else()
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra -Wno-unused-parameter -std=c++11 -pthread ${CAPNP_LITE_FLAG}")
+  # Note that it's important to add new CXXFLAGS before ones specified by the
+  # user, so that the user's flags override them. This is particularly
+  # important if -Werror was enabled and then certain warnings need to be
+  # disabled, as is done in super-test.sh.
+  #
+  # We enable a lot of warnings, but then disable some:
+  # * strict-aliasing: We use type-punning in known-safe ways that GCC doesn't
+  #   recognize as safe.
+  # * sign-compare: Low S/N ratio.
+  # * unused-parameter: Low S/N ratio.
+  #
+  # We have to use -std=gnu++0x isntead of -std=c++11 because otherwise we lose
+  # GNU extensions that we need.
+  set(CMAKE_CXX_FLAGS "-std=gnu++0x -Wall -Wextra -Wno-strict-aliasing -Wno-sign-compare -Wno-unused-parameter -pthread ${CAPNP_LITE_FLAG} ${CMAKE_CXX_FLAGS}")
 endif()
 
 # Source =======================================================================

c++/Makefile.am

@@ -37,7 +37,7 @@ clean-local:
 # the cmake build.
 distcheck-hook:
 	rm -rf distcheck-cmake
-	(which cmake && mkdir distcheck-cmake && cd distcheck-cmake && cmake ../$(distdir) && make -j6 check)
+	(mkdir distcheck-cmake && cd distcheck-cmake && cmake ../$(distdir) && make -j6 check)
 	rm -rf distcheck-cmake
 
 AM_CXXFLAGS = -I$(srcdir)/src -I$(builddir)/src -DKJ_HEADER_WARNINGS -DCAPNP_HEADER_WARNINGS -DCAPNP_INCLUDE_DIR='"$(includedir)"' $(PTHREAD_CFLAGS)

c++/src/capnp/rpc.h

@@ -333,7 +333,10 @@ kj::Promise<kj::Own<_::VatNetworkBase::Connection>>
 
 template <typename SturdyRef>
 Capability::Client SturdyRefRestorer<SturdyRef>::baseRestore(AnyPointer::Reader ref) {
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   return restore(ref.getAs<SturdyRef>());
+#pragma GCC diagnostic pop
 }
 
 template <typename VatId>

c++/src/capnp/serialize-test.c++

@@ -274,7 +274,7 @@ public:
     data.append(reinterpret_cast<const char*>(buffer), size);
   }
 
-  const bool dataEquals(kj::ArrayPtr<const word> other) {
+  bool dataEquals(kj::ArrayPtr<const word> other) {
     return data ==
         std::string(other.asChars().begin(), other.asChars().size());
   }

c++/src/kj/async-unix.c++

@@ -149,7 +149,12 @@ void registerReservedSignal() {
   registerSignalHandler(reservedSignal);
 
   // We also disable SIGPIPE because users of UnixEventLoop almost certainly don't want it.
-  KJ_SYSCALL(signal(SIGPIPE, SIG_IGN));
+  while (signal(SIGPIPE, SIG_IGN) == SIG_ERR) {
+    int error = errno;
+    if (error != EINTR) {
+      KJ_FAIL_SYSCALL("signal(SIGPIPE, SIG_IGN)", error);
+    }
+  }
 }
 
 pthread_once_t registerReservedSignalOnce = PTHREAD_ONCE_INIT;
@@ -746,7 +751,8 @@ bool UnixEventPort::wait() {
 }
 
 bool UnixEventPort::poll() {
-  bool woken = false;
+  // volatile so that longjmp() doesn't clobber it.
+  volatile bool woken = false;
 
   sigset_t pending;
   sigset_t waitMask;

mega-test.cfg

-linux-gcc-4.9      9081 ./super-test.sh tmpdir capnp-gcc-4.9 gcc-4.9
-linux-gcc-4.8      8358 ./super-test.sh tmpdir capnp-gcc-4.8 gcc-4.8
-linux-clang        9165 ./super-test.sh tmpdir capnp-clang clang
-mac                6421 ./super-test.sh remote beat caffeinate
-cygwin             9770 ./super-test.sh remote Kenton@flashman
-exotic             4216 ./super-test.sh tmpdir exotic exotic
+linux-gcc-4.9     10520 ./super-test.sh tmpdir capnp-gcc-4.9 gcc-4.9
+linux-gcc-4.8      9800 ./super-test.sh tmpdir capnp-gcc-4.8 gcc-4.8
+linux-clang       10616 ./super-test.sh tmpdir capnp-clang clang
+mac                7942 ./super-test.sh remote beat caffeinate
+cygwin             9044 ./super-test.sh remote Kenton@flashman
+exotic             5581 ./super-test.sh tmpdir exotic exotic

super-test.sh

@@ -60,7 +60,7 @@ while [ $# -gt 0 ]; do
       echo "Pushing code to $HOST..."
       echo "========================================================================="
       BRANCH=$(git rev-parse --abbrev-ref HEAD)
-      ssh $HOST 'rm -rf tmp-test-capnp && mkdir tmp-test-capnp && git init tmp-test-capnp'
+      ssh $HOST 'chmod -R +w tmp-test-capnp && rm -rf tmp-test-capnp && mkdir tmp-test-capnp && git init tmp-test-capnp'
       git push ssh://$HOST/~/tmp-test-capnp "$BRANCH:test"
       ssh $HOST "cd tmp-test-capnp && git checkout test"
       scp -qr c++/gtest $HOST:~/tmp-test-capnp/c++/gtest
@@ -209,8 +209,9 @@ done
 # Enable lots of warnings and make sure the build breaks if they fire.  Disable strict-aliasing
 # because GCC warns about code that I know is OK.  Disable sign-compare because I've fixed more
 # sign-compare warnings than probably all other warnings combined and I've never seen it flag a
-# real problem.
-export CXXFLAGS="-O2 -DDEBUG -Wall -Werror -Wno-strict-aliasing -Wno-sign-compare -Wno-deprecated-declarations"
+# real problem. Disable unused parameters because it's stupidly noisy and never a real problem.
+# Disable missing-field-initializers because unfortuntaley gtest contains a warning of this class.
+export CXXFLAGS="-O2 -DDEBUG -Wall -Wextra -Werror -Wno-strict-aliasing -Wno-sign-compare -Wno-unused-parameter -Wno-missing-field-initializers"
 
 STAGING=$PWD/tmp-staging
 
@@ -238,14 +239,13 @@ else
 fi
 
 if [ $IS_CLANG = yes ]; then
-  # There's an unused private field in gtest.
-  export CXXFLAGS="$CXXFLAGS -Wno-unused-private-field"
+  # There's an unused private field in gtest, which Clang dislikes.
+  #
+  # Also, don't fail out on this ridiculous "argument unused during compilation" warning.
+  export CXXFLAGS="$CXXFLAGS -Wno-unused-private-field -Wno-error=unused-command-line-argument"
 else
-  # GCC 4.8 emits a weird uninitialized warning in kj/parse/char-test, deep in one of the parser
-  # combinators.  It could be a real bug but there is just not enough information to figure out
-  # where the problem is coming from, because GCC does not provide any description of the inlining
-  # that has occurred.  Since I have not observed any actual problem (tests pass, etc.), I'm
-  # muting it for now.
+  # GCC emits uninitialized warnings all over and they seem bogus. We use valgrind to test for
+  # uninitialized memory usage later on.
   CXXFLAGS="$CXXFLAGS -Wno-maybe-uninitialized"
 fi