GDV-58: [CPP] Fix order of includes. (apache#25)

* GDV-58: [CPP] Fix order of includes.

Fixing the order of includes to follow style guideline.
The order to follow is documented here : https://google.github.io/styleguide/cppguide.html#Names_and_Order_of_Includes
Also enabled the check in lint.

Author: praveenbingo

src/gandiva/src/cpp/build-support/cpplint.py

@@ -4636,6 +4636,11 @@ def _ClassifyInclude(fileinfo, include, is_system):
   if is_system and os.path.splitext(include)[1] in ['.hpp', '.hxx', '.h++']:
       is_system = False
 
+  # Arrow and LLVM do not export .hpp headers, forcing to recognize
+  # that these are not c system headers.
+  if is_system and include.split('/')[0] in ['arrow', 'llvm', 'gtest']:
+      is_system = False
+
   if is_system:
     if is_cpp_h:
       return _CPP_SYS_HEADER

src/gandiva/src/cpp/cmake/BuildUtils.cmake

@@ -101,7 +101,7 @@ function(add_lint)
     ${CPPLINT_BIN}
     --verbose=2
     --linelength=90
-    --filter=-whitespace/comments,-readability/todo,-build/header_guard,-build/c++11,-runtime/references,-build/include_order
+    --filter=-whitespace/comments,-readability/todo,-build/header_guard,-build/c++11,-runtime/references
     )
   endif (UNIX)
 endfunction(add_lint)

src/gandiva/src/cpp/include/gandiva/arrow.h

@@ -18,6 +18,7 @@
 
 #include <memory>
 #include <vector>
+
 #include <arrow/builder.h>
 #include <arrow/record_batch.h>
 #include <arrow/type.h>

src/gandiva/src/cpp/include/gandiva/projector.h

@@ -19,6 +19,7 @@
 #include <memory>
 #include <utility>
 #include <vector>
+
 #include "gandiva/arrow.h"
 #include "gandiva/expression.h"
 #include "gandiva/status.h"

src/gandiva/src/cpp/include/gandiva/tree_expr_builder.h

@@ -18,6 +18,7 @@
 
 #include <string>
 #include <vector>
+
 #include "gandiva/expression.h"
 
 namespace gandiva {

src/gandiva/src/cpp/src/codegen/annotator.cc

@@ -12,9 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include "codegen/annotator.h"
+
 #include <memory>
 #include <string>
-#include "codegen/annotator.h"
+
 #include "codegen/field_descriptor.h"
 
 namespace gandiva {

src/gandiva/src/cpp/src/codegen/annotator.h

@@ -17,12 +17,13 @@
 
 #include <list>
 #include <string>
-#include <vector>
 #include <unordered_map>
+#include <vector>
+
+#include "codegen/eval_batch.h"
 #include "gandiva/arrow.h"
 #include "gandiva/gandiva_aliases.h"
 #include "gandiva/logging.h"
-#include "codegen/eval_batch.h"
 
 namespace gandiva {
 

src/gandiva/src/cpp/src/codegen/annotator_test.cc

@@ -12,10 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include "codegen/annotator.h"
+
 #include <memory>
-#include <gtest/gtest.h>
+
 #include <arrow/memory_pool.h>
-#include "codegen/annotator.h"
+#include <gtest/gtest.h>
 #include "codegen/field_descriptor.h"
 
 namespace gandiva {

src/gandiva/src/cpp/src/codegen/dex.h

@@ -17,13 +17,14 @@
 
 #include <string>
 #include <vector>
-#include "gandiva/gandiva_aliases.h"
+
 #include "codegen/dex_visitor.h"
 #include "codegen/field_descriptor.h"
 #include "codegen/func_descriptor.h"
 #include "codegen/literal_holder.h"
 #include "codegen/native_function.h"
 #include "codegen/value_validity_pair.h"
+#include "gandiva/gandiva_aliases.h"
 
 namespace gandiva {
 

src/gandiva/src/cpp/src/codegen/dex_llvm_test.cc

@@ -12,10 +12,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <gtest/gtest.h>
+#include "codegen/dex.h"
+
 #include <map>
 #include <typeinfo>
-#include "codegen/dex.h"
+
+#include <gtest/gtest.h>
 
 namespace gandiva {