- CMake: added option to turn fail compilation if warning occurs, and warning level 4 with MSVC.

- Fixed some warnings

CMakeLists.txt

@@ -4,6 +4,7 @@ ENABLE_TESTING()
 
 OPTION(JSONCPP_WITH_TESTS "Compile and run JsonCpp test executables" ON)
 OPTION(JSONCPP_WITH_POST_BUILD_UNITTEST "Automatically run unit-tests as a post build step" ON)
+OPTION(JSONCPP_WITH_WARNING_AS_ERROR "Force compilation to fail if a warning occurs" OFF)
 
 # Ensures that CMAKE_BUILD_TYPE is visible in cmake-gui on Unix
 IF(NOT WIN32)
@@ -61,9 +62,27 @@ MESSAGE(STATUS "JsonCpp Version: ${JSONCPP_VERSION_MAJOR}.${JSONCPP_VERSION_MINO
 CONFIGURE_FILE( "${PROJECT_SOURCE_DIR}/src/lib_json/version.h.in"
                 "${PROJECT_SOURCE_DIR}/include/json/version.h" )
 
+macro(UseCompilationWarningAsError)
+	if ( MSVC )
+        # Only enabled in debug because some old versions of VS STL generate
+        # warnings when compiled in release configuration.
+		set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /WX ")
+	endif( MSVC )
+endmacro() 
+
 # Include our configuration header
 INCLUDE_DIRECTORIES( ${CMAKE_SOURCE_DIR}/include )
 
+if ( MSVC )
+    # Only enabled in debug because some old versions of VS STL generate
+    # unreachable code warning when compiled in release configuration.
+    set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /W4 ")
+endif( MSVC )
+
+IF(JSONCPP_WITH_WARNING_AS_ERROR)
+    UseCompilationWarningAsError()
+ENDIF(JSONCPP_WITH_WARNING_AS_ERROR)
+
 # Build the different applications
 ADD_SUBDIRECTORY( src )
 

src/lib_json/json_value.cpp

@@ -1805,7 +1805,7 @@ Path::makePath( const std::string &path,
 
 
 void 
-Path::addPathInArg( const std::string &path, 
+Path::addPathInArg( const std::string &/*path*/, 
                     const InArgs &in, 
                     InArgs::const_iterator &itInArg, 
                     PathArgument::Kind kind )
@@ -1826,8 +1826,8 @@ Path::addPathInArg( const std::string &path,
 
 
 void 
-Path::invalidPath( const std::string &path, 
+Path::invalidPath( const std::string &/*path*/, 
-                   int location )
+                   int /*location*/ )
 {
    // Error: invalid path.
 }

src/test_lib_json/jsontest.cpp

@@ -480,10 +480,10 @@ Runner::runCommandLine( int argc, const char *argv[] ) const
 }
 
 
-#if defined(_MSC_VER)
+#if defined(_MSC_VER)  &&  defined(_DEBUG)
 // Hook MSVCRT assertions to prevent dialog from appearing
 static int 
-msvcrtSilentReportHook( int reportType, char *message, int *returnValue )
+msvcrtSilentReportHook( int reportType, char *message, int * /*returnValue*/ )
 {
    // The default CRT handling of error and assertion is to display
    // an error dialog to the user.
@@ -517,9 +517,11 @@ msvcrtSilentReportHook( int reportType, char *message, int *returnValue )
 void 
 Runner::preventDialogOnCrash()
 {
-#if defined(_MSC_VER)
+#if defined(_MSC_VER)  &&  defined(_DEBUG)
    // Install a hook to prevent MSVCRT error and assertion from
-   // popping a dialog.
+   // popping a dialog
+   // This function a NO-OP in release configuration 
+   // (which cause warning since msvcrtSilentReportHook is not referenced)
    _CrtSetReportHook( &msvcrtSilentReportHook );
 #endif // if defined(_MSC_VER)
 

src/test_lib_json/jsontest.h

@@ -193,7 +193,7 @@ namespace JsonTest {
       if ( static_cast< U >( expected ) != actual )
       {
          result.addFailure( file, line, expr );
-         result << "Expected: " << expected << "\n";
+         result << "Expected: " << static_cast< U >( expected ) << "\n";
          result << "Actual  : " << actual;
       }
       return result;